bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning backlight for motion‐blur reduction on mobile displays
Authors: Onac Gabriel‐Eugen , Vogels Ingrid , Bartula Marek , Hoevenaars Albert , Louwsma Hendrik Klaas
Published: January 2008

Abstract— Small‐form‐factor liquid‐crystal displays (LCDs) are mainly used in mobile applications (e.g., mobile phones, PDAs, and portable game consoles) but also in digital still cameras, video cameras, automotive applications, etc. Like all active‐matrix LCDs, mobile displays suffer from motion blur caused by the sample‐and‐hold effect. One option for improving the motion portrayal on active‐matrix LCDs is the use of a scanning backlight, which results in an imaging behavior similar to the one present in impulsive displays. In this paper, the realization of a scanning backlight for mobile displays is reported. This employs a backlight with seven individually lit segments for reducing the motion blur. Results of perception experiments performed with two identical displays confirm the benefit of using this technology. Optimal driving conditions result in a major improvement in motion portrayal on mobile LCDs.
Experimental and theoretical luminous efficacies of phosphors used in combination with blue‐emitting LEDs for lighting and backlighting
Authors: Withnall Robert , Silver Jack , Fern George R. , Ireland Terry G. , Lipman Anthony L. , Patel Birju
Published: January 2008

Abstract— Phosphors that absorb blue light and emit in the green, yellow, and red have been synthesized, and their experimental and theoretical luminous efficacies are compared. It is proposed that a blue‐emitting LED in combination with red‐emitting Sr2Si5N8: Eu2+ and green‐emitting SrGa2S4: Eu2+ phosphors is used as an energy‐efficient white‐light source for display backlighting applications.
A study on spot distortion for an in‐line self‐converging system for color CRTs
Authors: Wada Yasufumi
Published: January 2008

Abstract— The spot distortion at the screen periphery of an in‐line self‐converging CRT is formulated by considering four factors; (a) oblique incidence of the beam at the screen periphery, (b) increased path length of the beam, (c) beam compression due to the deflection, and (d) the astigmatism due to the deflection field. The analytic spot size calculated with the formulas agrees well with measurement, though the effects of a particular gun system, spherical aberration, and space‐charge repulsion are not taken into consideration in the formulas while assuming an ideal deflection field. The analytic formulas enable easy evaluation of spot distortion at the screen periphery because they give an intuitive understanding of beam behavior in the in‐line self‐converging system. In addition to the derivation of the formulas, “transposed scanning” is analyzed with the use of the formulas for one of the ways to optimize the spot distortion at the screen periphery.
Managed Pressure Drilling Resolves Pressure Depletion Related Problems in the Development of the HPHT Kristin Field
Authors: Solvang S. A. , Leuchtenberg C. , Gil I. C. , Pinkstone H.
Published: January 2008

Depletion of the Kristin HPHT field (911 bar, 172° C / 13,213 psi, 342° F) is occurring, challenging the drilling of future increased recovery wells. The main concern is uncertainty of the reservoir pressures in development areas of the producing intervals. Initially, the operational window range for the bottomhole pressure (BHP) varied from a pore pressure of 1.97 SG to a fracture pressure of 2.14-2.16 SG. With depletion, the difference has become narrower since fracture pressure is decreasing.

This paper describes the need to implement managed pressure drilling (MPD) techniques in the Kristin field to overcome the problems related to a narrow drilling window. MPD is a technique that allows the use of lower-density drilling fluid, minimizing the overbalance pressure. Thus, BHP can be easily controlled and changed by applying surface-back pressure using a closed and pressurized circulation system and an automated choke. Circulating and static BHP can be increased rapidly, by applying back pressure at surface, if a higher than expected reservoir pressure is encountered. Conversely, BHP can rapidly be reduced, by reducing surface back pressure, should losses be seen down hole.

The paper will discuss the use of a drilling fluid with a density giving a hydrostatic pressure lower than the original pore pressure to facilitate drilling operations and allow better control of the BHP for drilling future wells in the Kristin Field.

The Kristin development wells may be the first wells globally to use MPD techniques in a harsh weather offshore environment on a floating drilling installation. The paper will also discuss some of the new equipment which has been designed to allow the implementation of MPD techniques in a harsh weather offshore environment from a semi submersible rig.
Successful Use of Underbalanced-Drilling in a Cluster of Fields, North Oman
Authors: Carrera Mariano , Al Hadhrami Hamed , Al Jabri Hamed
Published: January 2008

Under-Balance Drilling (UBD) has been used in several carbonate fields of the Cluster, North Oman at Petroleum Development Oman (PDO). The reasons have been to improve productivity and injectivity, real-time reservoir characterization and to reduce/eliminate acid clean out. By using UBD in several fields, a better picture of well candidate selection and benefits has been derived.

In this paper we will present the results of successful utilization of UBD that may be applied to other fields. The results include an improvement in productivity, real-time decision making and a better understanding of reservoir flow characteristics. In summary the success of UBD depends on the selection of the fields which we elaborate on using several examples. These examples will demonstrate in details the history, application and benefits of UBD. The presentation will also illustrate future work planned using UBD.
Constant Bottomhole Pressure: Managed-Pressure Drilling Technique Applied in an Exploratory Well in Saudi Arabia
Authors: Vieira P. , Arnone M. , Russel B. , Cook I. , Moyse K. , Torres F. , Qutob Hani , Yuesheng Chen , Qing Chen
Published: January 2008

The proposed well is an exploratory well where the formation pressures were estimated based on the experience in drilling offset wells in the area. The 8 3/8" and 5 7/8" hole sections, have a wide range of predicted pore pressure, indicating a considerable span of uncertainty in addition to other related conventional drilling problems as tight hole and gas influx. In previous wells drilled in the area, many drilling problems and wellbore stability issues were experienced. One of the possible cuases of the mechanical instability could be attributed to the large fluctuations in the bottom hole pressure that is intrinsic to conventional drilling practices. These fluctuations are originated from the stopping and starting of drilling fluid circulation during jointed pipe connections, specifically, they result from the fluctuation in the equivalent circulating density (ECD), which occurs when the pumps are turned on and off. This fluctuation could triger a kick-Loss scenario that increases the Non Productive Time (NPT). drilling-related flat time further indicate a necessity for a technology that enables more precise wellbore pressure management.

Constant Bottom Hole Pressure (CBHP) which is variation of MPD, is applicable to avoid changes in ECD by applying appropriate levels of surface backpressure, a technique that maintains constant bottom-hole pressure during the complete drilling operation. The primary objective of drilling this well using the Managed Pressured Drilling technology was to reach the target depth with minimum drilling complication, avoid uncontrolled event by maintaining a constant bottom hole pressure and properly managing the well in case an underbalanced condition occurs while drilling the 8 3/8" and 5 7/8" hole sections.

As with any advanced drilling technique, successful application of MPD technology required a detailed understanding of the potential benefits as well as limitations. This paper summarizes the process that was used to identify, plan, and implement MPD as a technology to drill the well to the target depth and prevent conventional. Planning and operational results are presented in this paper.
Combined Underbalanced/Coiled-Tubing Drilling Technologies Have Improved Oil Recovery and Activated Abandoned Wells in Hassi Messaoud Field, Algeria
Authors: Amor Bachir Ben , Ferhat Ali , Messas Rafik , Arnone Maurizio , Schoch Fritz , Vieira Paco , Chopty James , Qutob Hani
Published: January 2008

The combination of Underbalanced and Coiled Tubing Drilling technologies has proven to be a viable solution to successfully drill horizontal re-entry wells in mature fields where the reservoir pressure is adequate to induce underbalanced conditions using single phase or multiphase drilling fluid injection.

This is the first of its kind Underbalanced-Coiled Tubing Drilling project undertaken in Hassi Messaoud field. The candidate wells are from a pool of vertical abandoned wells drilled in the western area of the field and have seized to produce with varying completion string and production casing. The increase in the number of candidates for thru tubing re-entries in addition to the depletion of the reservoir, have raised the importance of using the combined Underbalanced-Coiled Tubing Drilling technologies in Hassi Messaoud field.

The experience in this field has validated the benefits of the combination of these technologies and has been attributed to the excellent balance between drilling cost and improved productivity. For example, the drilling cost in the short radius re-entry wells drilled with coiled tubing are highly reduced due to the elimination of pipe connection procedures, the increase in rate of penetration, prevention of conventional drilling problems such as fluid circulation loses and related differential sticking events, increase in the bit life and reduction in time and drilled distance to reach the profitable production level.

This paper describes the technical basis for the design of the Underbalanced-Coiled Tubing Drilling project in Hassi Messaoud field-Algeria, and highlights the operational results, key factors and challenges faced during three consecutive successful re-entry wells drilled in this field.
MPD Planning: How Much Is Enough?
Authors: Spriggs Paul , Frink Philip J.
Published: January 2008

The purpose of this paper is to address the key drivers and risks associated with the use of Applied Back Pressure Managed Pressure Drilling. One of the two key issues to understand early on is whether the well can be drilled statically overbalanced or needs to be drilled with a statically underbalanced fluid. The second issue to comprehend is the level of service needed to avoid compromising safety and well objectives. Answering these two questions defines the path to be followed for adequate planning.

Detailed planning aspects, such as flow modeling, crew training, operational procedures, process flow diagrams and HAZID / HAZOPs meetings are also described in this paper. By asking the ‘what if’ questions prior to operations, it should become apparent what additional surface equipment is required to safely and efficiently drill in MPD mode. Control of the ‘what if's should help to keep the planning and rig up both reasonable and cost effective.
Underbalanced Drilling Operation for Reservoir Characterization in Jebel Aswad Field, Oman - A Case History
Authors: Nellayappan Karthik , Azzam Zaher , Vieira Paco , Rambo Dean , Moyse Keith , Cook Iain , Kelly Jim , Hengveld Bas
Published: January 2008

Underbalanced (UBD) operations are being utilized with increasing frequency as a means of reducing invasive formation damage, minimizing problems with differential sticking, lost circulation, and increasing rates of penetration in many drilling operations. Additional to the operational benefits, the underbalanced drilling technology is nowadays utilized as a tool formation characterization associated with the reservoir fluids.

Tethys Oil Oman Ltd. has successfully drilled the first underbalanced well, Jebel Aswad 1 in Jebel Aswad field in Block 15. Two lateral re-entry wells were drilled, STK1 & STK2 into Shuaiba and Natih reservoir respectively, using Underbalanced drilling technique. The shuaiba reservoir is composed primarily of micritic lime mudstone, which generally has a moderate to good porosity with poor permeability. The Natih reservoir is a fractured chalky limestone with a predominantly low permeability matrix. The main objective was to drill 6-1/8" hole into the horizontal reservoir sections in underbalance condition to reduce/minimize formation damage and to evaluate production while drilling. Drilling the reservoir in underbalanced mode allowed for an early reservoir characterization.

This paper discusses the objectives, planning, drilling technology used, problems encountered and lessons learned during the first application of Underbalanced Drilling in Jebel Aswad field for Tethy Oil Oman Ltd.
Simplifying MPD: Lessons Learned
Authors: Medley George H. , Moore Dennis , Nauduri Sagar
Published: January 2008

Managed Pressure Drilling has gained widespread popularity and a great deal of press coverage in recent years. By applying MPD techniques, it is possible to drill holes that simultaneously expose formations with pore pressures very close to the frac pressures of other exposed formations with minimal formation influx or mud losses. Complex and expensive systems have been designed and implemented to maintain pressure on the wellbore using hydraulics modeling software, automated chokes, and continuous surface circulating systems, often working in conjunction with each other. These systems usually require several specially trained operators. This aggregation of personnel and equipment increases both the footprint and housing required for implementation, as well as substantially increasing the cost of the operation.

MPD replaces the pressure exerted by static mud weight with dynamic friction pressure to maintain control of the well without losing returns. The objective of the technique is to maintain wellbore pressure between the pore pressure of the highest pressured formation and the frac pressure of the weakest. This is usually done by drilling with a mud weight whose hydrostatic gradient is less than what is required to balance the highest pore pressure, with the difference made up using dynamic friction while circulating. That sounds quite simple but has been made extremely complicated.

The big problem is maintaining constant wellbore pressure while transitioning between circulating with little or no annular pressure and shut-in with proper annular pressure to maintain balance. A great deal of time and money has gone into trying to do this with no change in wellbore pressure throughout the process. Field experience has shown that this is not necessarily cost effective, demanding an answer to the question, "Is all this complexity really necessary?" The answer in many cases is "No."
First Multilateral Well Drilled With Underbalanced Drilling Technology in Sabria Field—Tunisia
Authors: McMechan Roger , Beaudry Julien , Beaudry Raymond , Arnone Maurizio , Al Heureithi Wesam , Vieira Paco , Chopty James
Published: January 2008

Underbalanced Drilling (UBD) technology has been applied around the world to drill wells where it is imperative to obtain benefits, as it minimizes the formation damage that is common result in conventional overbalanced drilling operations. In addition to minimizing formation damage, other benefits related to Underbalanced Drilling include increase of penetration rate, elimination of lost circulation problems, elimination of differential pipe sticking and reservoir evaluation while the well is being drilled.

The reservoir screening analysis and the engineering feasibility study performed during the planning stage of this project determined that the Hamra reservoir is a good candidate for underbalanced drilling technology application.

Based on the reservoir pressure and the Lower Hamra formation depth in the Sabria field, a weighted drilling fluid system was required to achieve a controlled drawdown and therefore underbalanced drilling conditions. Comprehensive hydraulic simulations were carried out to determine the required liquid injection rate and back pressure on the choke manifold to ensure safe and manageable drilling conditions. The simulations were also used to predict the anticipated hole cleaning and the impact of reservoir production due to downhole hydraulic conditions while drilling.

Drilling the Multilateral Well A in underbalanced condition allowed Winstar Resources Ltd to evaluate the reservoir and successfully acquire real time reservoir characterization data and production capability of the well while drilling.

A multidisciplinary team contributed to the engineering, planning and execution of the Underbalanced Drilling operation. This paper discusses the planning phase, operational results, lessons learned and recommendations that will permit to improve the UBD benefits for future wells to be drilled in the area.
Performing the Dynamic Shut-In Procedure Because of a Kick Incident When Using Automatic Coordinated Control of Pump Rates and Choke-Valve Opening
Authors: Carlsen Liv A. , Nygaard Gerhard , Gravdal Jan Einar , Nikolaou Michael , Schubert Jerome
Published: January 2008

Automatic drilling operations using different Managed Pressure Drilling (MPD) technologies such as annulus backpressure systems or dual-gradient systems require investigation of the system's ability to operate during various kick incidents. Due to the increased instrumentation typically available in MPD operations, kick incidents can be identified earlier compared to more traditional methods using evaluation of the pit gain. Since early kick detection is possible, the use of new well shut-in procedures such as the dynamic shut-in procedure will probably be accepted as more appropriate during MPD operations. This paper describes how the dynamic shut-in procedure can be performed during a kick incident occurring during drilling.

The main pumps and the choke valve opening are operated using the automatic coordinated control system. The dynamic shut-in procedure is evaluated using a detailed dynamic multi-phase flow model, and the case used for the evaluation is based on the requirements from an off-shore drilling operation of a well in the North Sea. The dynamic shut-in procedure is followed by a procedure using the automatic coordinated control system to displace the kick, and the procedure is compared to both Driller's Method and the Wait and Weight method.

The results show that using the dynamic shut-in procedure together with the automatic coordinated control system reduces the time needed to establish control of the well as compared to the more traditional well control procedures. The results also indicate that introducing the dynamic shut-in procedure reduces the total risk for the whole drilling operation.
Modeling of an Underbalanced Drilling Operation Utilizing Supercritical Carbon Dioxide
Authors: Al-Adwani Faisal , Langlinais Julius P. , Hughes Richard
Published: January 2008

Mechanistic modeling of an underbalanced drilling operation using carbon dioxide has been developed in this research. The use of carbon dioxide in an underbalanced drilling operation eliminates some of the operational difficulties inherent with gaseous drilling fluids, such as generating enough torque to run a downhole motor. The unique properties of CO2, both inside the drill pipe and the annulus are shown in terms of optimizing the drilling operation by achieving a low bottom hole pressure window. Typically, CO2 becomes supercritical inside the drill pipe at this high density; it thus can generate enough torque to run a downhole motor. As the fluid exits the drill bit it will evaporate to a gas, hence achieving the required low density for underbalanced drilling.

The latest CO2 equation of state to calculate the required thermodynamic fluid properties is used. In addition, a heat transfer model that takes into account varying properties of both pressure and temperature has been developed. A marching algorithm procedure is developed to calculate the circulating fluid pressure and temperature, taking into account the varying parameters. Both single phase CO2 and a mixture of CO2 and water have been studied to show the effect of produced water on corrosion rates. The model also is capable of handling different drill pipe and annular geometries.
Applying Underbalanced Drilling Technology Improves Productivity and Enhances Recovery in Libya
Authors: Gaaim A. M. , Qutob Hani
Published: January 2008

Recent trends in the Oil & Gas industry have been toward the utilization of new technologies in order to optimize production and improve recovery. The National Oil Corporation (NOC) of Libya is considering deploying Under-balanced Drilling (UBD) technology as one of the most effective methods when it is effectively applied in conjunction with horizontal and/or Multi-lateral well drilling and completion techniques

Under-Balanced Drilling Technology has enabled the commercial development of numerous oil and gas reservoirs around the world that would have otherwise not been exploited due to technical and/or economic limitations. Under-Balanced Drilling has only become possible as a result of the integration of many developing technologies that facilitate directional control of the well trajectory, control of the bottom hole circulating pressure and the safe handling of drilling fluids and drill cuttings on surface.

When drilling Under-balanced, the annular pressure profile is maintained below the expected reservoir pore pressure and is particularly beneficial in evaluating the productivity of prospective formations in their virgin state. This means that the formation can be evaluated without being subjected to damage during conventional drilling and the required clean-up operations.

As of today, a total of three wells have been drilled under-balanced by ZUEITINA Oil Company in Libya. Through three examples, the paper will demonstrate that the key to selecting appropriate Reservoir candidates for UBD is achieving a balance of Technical, Safety and Economic factors.

This paper describes the Front End Engineering Design, Project Management, Risk Mitigation, Operational Results and Lessons Learned for this project.
Managed-Pressure Drilling and Downhole Isolation Technologies Deliver High Rate Gas Wells
Authors: Dharma Nyoman , Toralde J. S. S.
Published: January 2008

Pressurized MudCap Drilling (PMCD), a variant of Managed Pressure Drilling (MPD), is known for allowing drilling to continue despite a total loss of circulation, while at the same time monitoring and controlling the entry of influx into the wellbore. A weakness of this technique is that the well still has to be killed prior to pulling out of the hole, which can be timeconsuming and ultimately lead to reservoir damage. Utilizing a downhole isolation system to eliminate the need to kill the well during and after PMCD operations would therefore greatly improve the efficiency and effectiveness of this drilling technique and enhance its acceptability in operations where well productivity is a major consideration.

A combination of MPD and downhole isolation technologies was recently used successfully to drill a highly prolific, fractured gas reservoir in Suban Field, South Sumatra, Indonesia, resulting in wells capable of producing in excess of 300 mmscfd. MPD with downhole isolation allowed drilling to continue even with total loss of circulation, increased the safety margin of operations, reduced the amount of mud and lost circulation materials (LCM) required, minimized formation damage and made the running and installation of the completion assembly possible without the need to kill the well. The project demonstrated the clear and practical advantage that can be gained from combining these two technologies.

This paper focuses on how MPD and downhole isolation technologies were successfully integrated to produce high-rate gas wells in the Suban field and details how the system was effectively utilized for the first time to produce improvements in the safety and efficiency of drilling and completion operations, as compared to previous methods used in the area. It will also present the equipment, set-up, processes and procedures used in integrating these two technologies.
Resting Heart Rate in Middle Age and Diabetes Development in Older Age
Authors: Carnethon Mercedes R. , Yan Lijing , Greenland Philip , Garside Daniel B. , Dyer Alan R. , Metzger Boyd , Daviglus Martha L.
Published: January 2008

OBJECTIVE—Based on prior research showing inverse associations between heart rate and life expectancy, we tested the hypothesis that adults with higher resting heart rate in middle age were more likely to have diagnosed diabetes or to experience diabetes mortality in older age (>65 years).

RESEARCH DESIGN AND METHODS—Resting heart rate was measured at baseline (1967–1973) in the Chicago Heart Association Detection Project in Industry. We used Medicare billing records to identify diabetes-related hospital claims and non–hospital-based diabetes expenses from 1992 to 2002 in 14,992 participants aged 35–64 years who were free from diabetes at baseline. Diabetes-related mortality was determined from 1984 to 2002 using National Death Index codes 250.XX (ICD-8 and -9) and E10–E14 (ICD-10).

RESULTS—After age 65, 1,877 participants had diabetes-related hospital claims and 410 participants had any mention of diabetes on their death certificate. The adjusted (demographic characteristics, cigarette smoking, and years of Medicare eligibility) odds of having a diabetes-related claim was ∼10% higher (odds ratio [OR] 1.10 [95% CI 1.05–1.16]) per 12 bpm higher baseline heart rate. Following adjustment for BMI and postload glucose at baseline, the association attenuated to nonsignificance. Higher heart rate was associated with diabetes mortality in adults aged 35–49 years at baseline following adjustment for postload glucose and BMI (1.21 [1.03–1.41]).

CONCLUSIONS—Higher resting heart rate is associated with diabetes claims and mortality in older age and is only due in part to BMI and concurrently measured glucose.
Transplant Estimated Function
Authors: Caumo Andrea , Maffi Paola , Nano Rita , Bertuzzi Federico , Luzi Livio , Secchi Antonio , Bonifacio Ezio , Piemonti Lorenzo
Published: January 2008

OBJECTIVE—The β-score is a highly regarded approach to the assessment of transplant functionality. Our aim was to develop an index of β-cell function that hinges on the pillars of the β-score (daily insulin requirement and A1C), has a straightforward physiological interpretation, and does not require the execution of an insulin stimulation test.

RESEARCH DESIGN AND METHODS—The new index is denoted transplant estimated function (TEF) and is obtained from the daily insulin requirement and A1C. TEF estimates the amount of insulin secreted daily and can be normalized to the number of transplanted islets, thus permitting evaluation of the cost-effectiveness of the transplant. TEF was compared with the area under the curve of C-peptide [AUC(C-pep)] concentration over 24 h, as well as the acute insulin response to intravenous glucose (AIRglu) and to arginine (AIRarg). The association between TEF and β-score was also investigated.

RESULTS—The correlation of TEF with 24-h AUC(C-pep) was r = 0.73 (P < 0.005), whereas that for β-score versus 24-h AUC(C-pep) was r = 0.33 (NS). The correlation of TEF with AIRglu was r = 0.59 (P < 0.001) and close to that for β-score versus AIRglu (r = 0.65, P < 0.001). The correlation of TEF with AIRarg was r = 0.33 (P < 0.005) and was similar to that for β-score versus AIRarg (r = 0.34, P < 0.005). TEF and β-score were correlated well (r = 0.69, P < 0.0001) and showed similar time profiles.

CONCLUSIONS—TEF estimates daily insulin secretion, it is simpler than the β-score, and its performance against reference indexes of β-cell secretion is in line with that exhibited by β-score. TEF can be normalized to the number of transplanted islets and thereby provides a benchmarking tool to evaluate the cost-effectiveness of the transplant.
Pancreatic Exocrine Dysfunction in Maturity-Onset Diabetes of the Young Type 3
Authors: Vesterhus Mette , Ræder Helge , Johansson Stefan , Molven Anders , Njølstad Pål R.
Published: January 2008

OBJECTIVE—Exocrine pancreas dysfunction is seen in 10–30% of patients with type 1 and 2 diabetes. We have recently identified a syndrome of diabetes and exocrine pancreas dysfunction attributable to mutations in the carboxyl ester lipase (CEL) gene. We wanted to investigate the prevalence of pancreatic exocrine dysfunction in patients with maturity-onset diabetes of the young type 3 (MODY3).

RESEARCH DESIGN AND METHODS—All 119 patients with MODY3 in the Norwegian MODY Registry were invited to participate, and 70 (60.5%) responded, among whom 63 were adults. Control groups included 140 subjects with type 1 diabetes and 78 nondiabetic control subjects. Pancreatic dysfunction was defined by fecal elastase deficiency. Fecal fat excretion was measured in 25 patients with fecal elastase deficiency. CEL was investigated for sequence changes.

RESULTS—We found a prevalence of fecal elastase deficiency of 12.7% in adult patients with MODY3, compared with 18.6% in patients with type 1 diabetes and 3.8% in nondiabetic control subjects. The six patients with MODY3 with fecal elastase deficiency available for analysis all had increased fecal fat excretion. Fecal elastase decreased with age. Controlled for age, patients with MODY3 still had decreased fecal elastase compared with control subjects. Twelve of 70 patients (17%) had single-base insertions in CEL exon 11. Two of these had fecal elastase deficiency.

CONCLUSIONS—The prevalence of pancreatic exocrine dysfunction was 12.7% in a cohort of 63 adult patients with MODY3, similar to the prevalence among type 1 diabetic patients. Fecal fat excretion was increased in all patients with MODY3 with fecal elastase deficiency who were investigated, underscoring the potential clinical importance of the exocrine dysfunction.
Race/Ethnicity and Economic Differences in Cost-Related Medication Underuse Among Insured Adults With Diabetes
Authors: Tseng Chien-Wen , Tierney Edward F. , Gerzoff Robert B. , Dudley R. Adams , Waitzfelder Beth , Ackermann Ronald T. , Karter Andrew J. , Piette John , Crosson Jesse C. , Ngo-Metzger Quyen , Chung Richard , Mangione Carol M.
Published: January 2008

OBJECTIVE—To examine racial/ethnic and economic variation in cost-related medication underuse among insured adults with diabetes.

RESEARCH DESIGN AND METHODS—We surveyed 5,086 participants from the multicenter Translating Research Into Action for Diabetes Study. Respondents reported whether they used less medication because of cost in the past 12 months. We examined unadjusted and adjusted rates of cost-related medication underuse, using hierarchical regression, to determine whether race/ethnicity differences still existed after accounting for economic, health, and other demographic variables.

RESULTS—Participants were 48% white, 14% African American, 14% Latino, 15% Asian/Pacific Islander, and 8% other. Overall, 14% reported cost-related medication underuse. Unadjusted rates were highest for Latinos (23%) and African Americans (17%) compared with whites (13%), Asian/Pacific Islanders (11%), and others (15%). In multivariate analyses, race/ethnicity significantly predicted cost-related medication underuse (P = 0.048). However, adjusted rates were only slightly higher for Latinos (14%) than whites (10%) (P = 0.026) and were not significantly different for African Americans (11%), Asian/Pacific Islanders (7%), and others (11%). Income and out-of-pocket drug costs showed the greatest differences in adjusted rates of cost-related medication underuse (15 vs. 5% for participants with income ≤$25,000 vs. >$50,000 and 24 vs. 7% for participants with out-of-pocket costs >$150 per month vs. ≤$50 per month.

CONCLUSIONS—One in seven participants reported cost-related medication underuse. Rates were highest among African Americans and Latinos but were related to lower incomes and higher out-of-pocket drug costs in these groups. Interventions to decrease racial/ethnic disparities in cost-related medication underuse should focus on decreasing financial barriers to medications.
A Randomized Trial Comparing Continuous Subcutaneous Insulin Infusion of Insulin Aspart Versus Insulin Lispro in Children and Adolescents With Type 1 Diabetes
Authors: Weinzimer Stuart A. , Ternand Christine , Howard Campbell , Chang Cheng-Tao , Becker Dorothy J. , Laffel Lori M.B. ,   for the Insulin Aspart Pediatric Pump Study Group
Published: January 2008

OBJECTIVE—The safety and efficacy of insulin aspart continuous subcutaneous insulin infusion (CSII) was compared with that of insulin lispro CSII in children and adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS—Children and adolescents aged 4–18 years with diagnosed type 1 diabetes ≥1 year previously and treated with insulin analog in a CSII ≥3 months were randomly assigned 2:1 to 16 weeks of insulin aspart CSII (n = 198) or insulin lispro CSII (n = 100) in this open-label, parallel-group, multicenter study. Standard diabetes safety and efficacy parameters were assessed.

RESULTS—Baseline demographics, subject characteristics, and diabetes history were similar between treatment groups. After 16 weeks of treatment, insulin aspart CSII was noninferior to insulin lispro CSII as measured by change in A1C from baseline (aspart, −0.15 ± 0.05%; lispro, −0.05 ± 0.07% [95% CI of the treatment difference −0.27 to 0.07]; P = 0.241). No significant differences between treatment groups were observed in fasting plasma glucose, hyperglycemia, and rates of hypoglycemic episodes. At week 16, 59.7% of subjects in the aspart group and 43.8% of subjects in the lispro groups achieved age-specific American Diabetes Association A1C goals (<8.5% for subjects aged <6 years; <8% for subjects aged 6–18 years) (P = 0.040, corrected for baseline). Daily insulin dose (units per kilogram) was significantly lower at week 16 for subjects treated with aspart compared with those treated with lispro (0.86 ± 0.237 vs. 0.94 ± 0.233, P = 0.018).

CONCLUSIONS—Insulin aspart was as safe and effective as insulin lispro for use in a CSII in children and adolescents with type 1 diabetes.
Metabolic and Clinical Outcomes in Nondiabetic Individuals With the Metabolic Syndrome Assigned to Chlorthalidone, Amlodipine, or Lisinopril as Initial Treatment for Hypertension
Authors: Black Henry R. , Davis Barry , Barzilay Joshua , Nwachuku Chuke , Baimbridge Charles , Marginean Horia , Wright Jackson T. , Basile Jan , Wong Nathan D. , Whelton Paul , Dart Richard A. , Thadani Udho
Published: January 2008

OBJECTIVE—Optimal initial antihypertensive drug therapy in people with the metabolic syndrome is unknown.

RESEARCH DESIGN AND METHODS—We conducted a subgroup analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) to compare metabolic, cardiovascular, and renal outcomes in individuals assigned to initial hypertension treatment with a thiazide-like diuretic (chlorthalidone), a calcium channel blocker (CCB; amlodipine), or an ACE inhibitor (lisinopril) in nondiabetic individuals with or without metabolic syndrome.

RESULTS—In participants with metabolic syndrome, at 4 years of follow-up, the incidence of newly diagnosed diabetes (fasting glucose ≥126 mg/dl) was 17.1% for chlorthalidone, 16.0% for amlodipine (P = 0.49, chlorthalidone vs. amlodipine) and 12.6% for lisinopril (P < 0.05, lisinopril vs. chlorthalidone). For those without metabolic syndrome, the rate of newly diagnosed diabetes was 7.7% for chlorthalidone, 4.2% for amlodipine, and 4.7% for lisinopril (P < 0.05 for both comparisons). There were no differences in relative risks (RRs) for outcomes with amlodipine compared with chlorthalidone in those with metabolic syndrome; in those without metabolic syndrome, there was a higher risk for heart failure (RR 1.55 [95% CI 1.25–1.35]). In comparison with lisinopril, chlorthalidone was superior in those with metabolic syndrome with respect to heart failure (1.31 [1.04–1.64]) and combined cardiovascular disease (CVD) (1.19 [1.07–1.32]). No significant treatment group–metabolic syndrome interaction was noted.

CONCLUSIONS—Despite a less favorable metabolic profile, thiazide-like diuretic initial therapy for hypertension offers similar, and in some instances possibly superior, CVD outcomes in older hypertensive adults with metabolic syndrome, as compared with treatment with CCBs and ACE inhibitors.
Effective Treatment With Oral Sulfonylureas in Patients With Diabetes Due to Sulfonylurea Receptor 1 (SUR1) Mutations
Authors: Rafiq Meena , Flanagan Sarah E. , Patch Ann-Marie , Shields Beverley M. , Ellard Sian , Hattersley Andrew T. ,   The Neonatal Diabetes International Collaborative Group
Published: January 2008

OBJECTIVE—Neonatal diabetes can result from mutations in the Kir6.2 or sulfonylurea receptor 1 (SUR1) subunits of the ATP-sensitive K+ channel. Transfer from insulin to oral sulfonylureas in patients with neonatal diabetes due to Kir6.2 mutations is well described, but less is known about changing therapy in patients with SUR1 mutations. We aimed to describe the response to sulfonylurea therapy in patients with SUR1 mutations and to compare it with Kir6.2 mutations.

RESEARCH DESIGN AND METHODS—We followed 27 patients with SUR1 mutations for at least 2 months after attempted transfer to sulfonylureas. Information was collected on clinical features, treatment before and after transfer, and the transfer protocol used. We compared successful and unsuccessful transfer patients, glycemic control before and after transfer, and treatment requirements in patients with SUR1 and Kir6.2 mutations.

RESULTS—Twenty-three patients (85%) successfully transferred onto sulfonylureas without significant side effects or increased hypoglycemia and did not need insulin injections. In these patients, median A1C fell from 7.2% (interquartile range 6.6–8.2%) on insulin to 5.5% (5.3–6.2%) on sulfonylureas (P = 0.01). When compared with Kir6.2 patients, SUR1 patients needed lower doses of both insulin before transfer (0.4 vs. 0.7 units · kg−1 · day−1; P = 0.002) and sulfonylureas after transfer (0.26 vs. 0.45 mg · kg−1 · day−1; P = 0.005).

CONCLUSIONS—Oral sulfonylurea therapy is safe and effective in the short term in most patients with diabetes due to SUR1 mutations and may successfully replace treatment with insulin injections. A different treatment protocol needs to be developed for this group because they require lower doses of sulfonylureas than required by Kir6.2 patients.
Does Anodyne Light Therapy Improve Peripheral Neuropathy in Diabetes?
Authors: Lavery Lawrence A. , Murdoch Douglas P. , Williams Jayme , Lavery David C.
Published: January 2008

OBJECTIVE—The purpose of this study was to determine the efficacy of anodyne monochromatic infrared photo energy (MIRE) in-home treatments over a 90-day period to improve peripheral sensation and self-reported quality of life in individuals with diabetes.

RESEARCH DESIGN AND METHODS—This was a double-blind, randomized, sham-controlled clinical trail. We randomly assigned 69 individuals with diabetes and a vibration perception threshold (VPT) between 20 and 45 V to two treatment groups: active or sham treatment. Sixty patients (120 limbs) completed the study. Anodyne units were used at home every day for 40 min for 90 days. We evaluated nerve conduction velocities, VPT, Semmes-Weinstein monofilaments (SWM) (4-, 10-, 26-, and 60-g monofilaments), the Michigan Neuropathy Screening Instrument (MNSI), a 10-cm visual analog pain scale, and a neuropathy-specific quality of life instrument. We used a nested repeated-measures multiple ANOVA design. Two sites (great toe and fifth metatarsal) were tested on both the left and right feet of each patient, so two feet were nested within each patient and two sites were nested within each foot. To analyze the ordinal SWM scores, we used a nonparametric factorial analysis for longitudinal data.

RESULTS—There were no significant differences in measures for quality of life, MNSI, VPT, SWM, or nerve conduction velocities in active or sham treatment groups (P > 0.05).

CONCLUSIONS—Anodyne MIRE therapy was no more effective than sham therapy in the treatment of sensory neuropathy in individuals with diabetes.
Objectively Measured Sedentary Time, Physical Activity, and Metabolic Risk
Authors: Healy Genevieve N. , Wijndaele Katrien , Dunstan David W. , Shaw Jonathan E. , Salmon Jo , Zimmet Paul Z. , Owen Neville
Published: January 2008

OBJECTIVE—We examined the associations of objectively measured sedentary time and physical activity with continuous indexes of metabolic risk in Australian adults without known diabetes.

RESEARCH DESIGN AND METHODS—An accelerometer was used to derive the percentage of monitoring time spent sedentary and in light-intensity and moderate-to-vigorous–intensity activity, as well as mean activity intensity, in 169 Australian Diabetes, Obesity and Lifestyle Study (AusDiab) participants (mean age 53.4 years). Associations with waist circumference, triglycerides, HDL cholesterol, resting blood pressure, fasting plasma glucose, and a clustered metabolic risk score were examined.

RESULTS—Independent of time spent in moderate-to-vigorous–intensity activity, there were significant associations of sedentary time, light-intensity time, and mean activity intensity with waist circumference and clustered metabolic risk. Independent of waist circumference, moderate-to-vigorous–intensity activity time was significantly beneficially associated with triglycerides.

CONCLUSIONS—These findings highlight the importance of decreasing sedentary time, as well as increasing time spent in physical activity, for metabolic health.
Hypoglycemia in Type 1 Diabetes
Authors: Shalitin Shlomit , Phillip Moshe
Published: January 2008

The Diabetes Control and Complications Trial demonstrated that in patients with type 1 diabetes, tight metabolic control achieved with intensive insulin therapy can reduce the risk of long-term microvascular complications. However, strict glycemic control carries an increased risk of severe hypoglycemia. Recurrent episodes of hypoglycemia, especially at young ages, can lead to hypoglycemia unawareness, exert adverse effects on neurocognitive function, and cause significant emotional morbidity in the child and parents. Although the introduction of the new insulin analogs in diabetes therapy and the use of continuous subcutaneous insulin infusion raised hopes for a solution to this problem, these modalities have not been associated with the expected reduction in hypoglycemic episodes. The findings suggest that the prevention of hypoglycemia in patients with type 1 diabetes lies in biologically controlled insulin secretion, as in islet transplantation, or the development of an autonomous closed-loop system that efficiently mimics the action of the pancreatic β-cells and maintains blood glucose levels within the desired range.
Treatment of Type 2 Diabetes With Combined Therapy
Authors: Massi-Benedetti Massimo , Orsini-Federici Marco
Published: January 2008

Type 2 diabetes is a progressive syndrome that evolves toward complete insulin deficiency during the patient's life. A stepwise approach for its treatment should be tailored according to the natural course of the disease, including adding insulin when hypoglycemic oral agent failure occurs. Treatment with insulin alone should eventually be considered in a relevant number of cases. Experience has shown the protective effects of insulin on β-cell survival and function, resulting in more stable metabolic control. On the contrary, treatment with most insulin secretagogues has been associated with increased β-cell apoptosis, reduced responsiveness to high glucose, and impairment of myocardial function during ischemic conditions. In addition, macrovascular complications are associated with postprandial hyperglycemia, indicating the need for tight glycemic control. Insulin treatment, especially with rapid-acting analogs, has been demonstrated to successfully control postprandial glucose excursions. Finally, a reason for concern with regard to combined therapy is represented by the evidence that polipharmacy reduces compliance to the treatment regimen. This can be particularly relevant in patients with type 2 diabetes usually taking drugs for complications and for concomitant diseases with consequent deterioration not only of metabolic control but also of other conditions. In conclusion, therapy with insulin alone immediately after hypoglycemic oral agent failure may be a useful and safe therapeutic approach in type 2 diabetes.
Does Increased Oxidative Stress Cause Hypertension?
Authors: Grossman Ehud
Published: January 2008

Hypertension is associated with increased vascular oxidative stress; however, there is still a debate whether oxidative stress is a cause or a result of hypertension. Animal studies have generally supported the hypothesis that increased blood pressure is associated with increased oxidative stress; however, human studies have been inconsistent. Oxidative stress promotes vascular smooth muscle cell proliferation and hypertrophy and collagen deposition, leading to thickening of the vascular media and narrowing of the vascular lumen. In addition, increased oxidative stress may damage the endothelium and impair endothelium-dependent vascular relaxation and increases vascular contractile activity. All these effects on the vasculature may explain how increased oxidative stress can cause hypertension. Treatment with antioxidants has been suggested to lower oxidative stress and therefore blood pressure. However, to date, clinical studies investigating antioxidant supplements have failed to show any consistent benefit. It is noteworthy that lowering blood pressure with antihypertensive medications is associated with reduced oxidative stress. Therefore, it seems that oxygen stress is not the cause, but rather a consequence, of hypertension.
Diastolic Pressure in Type 2 Diabetes
Authors: Osher Etty , Stern Naftali
Published: January 2008

The practicality of vigorous lowering of systolic pressure in diabetes to <130 mmHg remains uncertain. Baseline blood pressure data from several recent trials indicate that, in diabetic subjects, there is nearly a fourfold excess in systolic pressure (the difference between baseline pressure and target pressure) over diastolic pressure with respect to the recommended systolic/diastolic target pressure of <130/80 mmHg. Additionally, systolic pressure was 2–3 mmHg higher and diastolic pressure was 1–3 mmHg lower in diabetic hypertensive than in nondiabetic hypertensive individuals, which adds ∼4 mmHg to pulse pressure and also to the difference between the excess systolic and excess diastolic pressure. We attempted to force (titrate both systolic and excess diastolic pressure) systolic and diastolic blood pressure to <130/85 mmHg based on Joint National Committee VI guidelines in the setting of a clinical practice in 257 diabetic patients. Although target systolic pressure was attained in a third of this cohort, in 57% of the patients, the attained diastolic pressure was ≤70 mmHg. Patients with final diastolic pressure <70 mmHg were older, had a higher prevalence of coronary artery disease, and had higher initial systolic and pulse pressures. Review of achieved blood pressure in studies such as the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) indicates that a significant fraction of the diabetic subjects’ diastolic pressure was also driven down to <70 mmHg or even <60 mmHg. Thus, attempted lowering of blood pressure to target systolic pressure is associated with inordinate lowering of diastolic pressure in a significant number of patients. Whether the benefits of tight systolic control to <130 mmHg outweigh the risks of excessive diastolic reduction, especially in older diabetic subjects or diabetic patients with coronary artery disease, remains unresolved.