CONCLUSIONS Antihypertensive treatment reduces the risk of mortality and cardiovascular morbidity in people with diabetes mellitus and a systolic blood pressure more than 140 mm Hg .
If systolic blood pressure is less than 140 mm Hg , however , further treatment is associated with an increased risk of cardiovascular death , with no observed benefit
OBJECTIVE To assess the effect of antihypertensive treatment on mortality and cardiovascular morbidity in people with diabetes mellitus , at different blood pressure levels .
Use of Enalapril To Attenuate Decline in Renal Function in Normotensive, Normoalbuminuric Patients with Type 2 Diabetes Mellitus
The concept of microalbuminuria has had a major impact on diabetes research and clinical care of patients with diabetes [ 1 - 5 ] . Initial albuminuria is regarded by most research ers as an independent predictor of subsequent progression of nephropathy and risk for cardiovascular morbidity and mortality [ 6 - 8 ] . Angiotensin-converting enzyme ( ACE ) inhibitors have been found to attenuate progression of nephropathy in both types of diabetes in hypertensive [ 9 - 12 ] and normotensive patients [ 13 - 15 ] with microalbuminuria . They were also found to lower urinary albumin excretion in normotensive and normoalbuminuric patients with type 1 diabetes [ 16 ] . The relation between albuminuria and later progression of nephropathy in these patients has not been established , possibly because of short follow-up periods . No data are available on the effect of early introduction of ACE inhibitors in normotensive and normoalbuminuric patients with type 2 diabetes mellitus . We design ed a r and omized , double-blind , placebo-controlled trial of the effect of ACE inhibition on the course of nephropathy in 156 patients with type 2 diabetes . These patients had normal blood pressure and normal urinary albumin excretion at baseline . Methods Patients Potential c and i date s were identified through the computerized records of the central regional laboratory for the northern part of the greater Tel-Aviv area . Persons with hyperglycemia and normal urinalysis results were located through their family physicians . Consent was sought once eligibility was established . Inclusion criteria were age younger than 60 years ; age 40 years or older at diagnosis ; duration of diabetes mellitus less than 10 years with no clinical evidence of malignant , autoimmune , hepatic , cardiovascular , or renal disease ; body mass index less than 30 kg/m2 ; normal blood pressure on at least two consecutive visits ( systolic pressure 140 mm Hg and diastolic pressure 90 mm Hg ; mean pressure 107 mm Hg ) ; serum creatinine concentration of 123 mol/L or less ; and urinary albumin excretion of 30 mg/24 h or less . All baseline data were obtained twice during the run-in prer and omization period . Patients were eligible only if values within the predetermined range were found on both examinations . The average of the values was used as the baseline value . A total of 255 patients who had type 2 diabetes according to World Health Organization criteria [ 17 ] and attended one of eight clinics in the greater Tel-Aviv area were found to be eligible and were contacted during 1990 and 1991 . Of these patients , 214 gave informed consent to participate . Twenty patients were excluded during the observation period : Six had blood pressure values above normal , 5 had microalbuminuria , 3 had serum creatinine concentrations above the trial criterion , 1 patient developed unstable angina pectoris , and 5 withdrew consent . Of the 194 patients included in the study , 102 were women and 92 were men ( mean age SD , 54.9 3.2 years [ range , 37 to 59 years ] ) . The known duration of diabetes was 0 to 9 years ( mean duration , 5.75 2.8 years ) . Patients were instructed to use the st and ard isocaloric diet recommended by the Israeli Diabetic Association , and 69 study patients used diet alone to control their hyperglycemia . Pharmacologic therapy for diabetes was insulin in 34 patients and oral hypoglycemic agents in 91 patients . Protocol The protocol was approved by the hospital review board . After a 2-month observation period , patients were r and omly assigned in a double-blind manner to receive enalapril ( Assia-Riezel Ltd. , Ramat-Gan , Israel ) , 10 mg/d , or placebo .  Ninety-seven patients were assigned to receive enalapril  , and 97 were assigned to receive placebo . R and omization was done central ly by telephone with a r and om number table [ 18 ] . Patient allocation to placebo or enalapril was recorded and kept by one of the authors . The placebo tablets were similar in appearance to the enalapril tablets . The medications , which came in sealed , numbered packages , were central ly prepared and were given to the patients at each visit by one nurse who was otherwise not involved in the study . Patients were followed by their family physicians , who were unaware of allocation . Two semiannual prescheduled visits took place each year , and interim visits were scheduled as clinical ly indicated . At the semiannual visits , hemoglobin A1c values , serum creatinine concentrations , serum electrolyte levels , and 24-hour albumin excretion and urinary creatinine concentrations were measured . Blood pressure was measured by the physicians twice at each visit by using mercury sphygmomanometers with the patients seated after a 5-minute rest ; physicians recorded the average of the two values . The diastolic pressure was determined at Korotkoff phase V. If a systolic blood pressure of 145 mm Hg or more or a diastolic blood pressure of 95 mm Hg or more was found , measurements were repeated weekly . If elevated values persisted on two consecutive visits , a long-acting calcium-channel blocker ( diltiazem or verapamil ) , hydrochlorothiazide , or both were administered . If systolic blood pressure values of 100 mm Hg or less were repeatedly found , the enalapril dosage was reduced to 5 mg/d ( half of a 10-mg enalapril tablet or half of a placebo tablet ) . Fundoscopy was done yearly by an ophthalmologist , and the presence of retinopathy was recorded . For each patient , follow-up was terminated 6 years after r and omization . Measurements All blood and urine sample s were examined by a central laboratory . Assays were not changed during the study period . Glycosylated hemoglobin values were measured by affinity chromatography with a commercial kit ( Isolab , Biochemical Methodology , Akron , Ohio ) . The normal range of this assay is a hemoglobin A1c value of 3.5 % to 5.6 % and an intra-assay and interassay coefficient of variability of less than 3 % . Urinary albumin concentration was measured twice in 24-hour urine sample s by an automated immunoturbidimetric method [ 19 ] . This procedure has intra-assay and interassay coefficients of variability of 5.9 % and 7.6 % , respectively . Creatinine concentrations were determined by using the automated method of Bartels and colleagues [ 20 ] . Creatinine clearance , normalized for 1.73 m2 of body surface area , was calculated for each visit by using the st and ard formula ( urine creatinine x urine volume/plasma creatinine ) . The mean blood pressure ( defined as the diastolic pressure plus one third of the pulse pressure ) was calculated at each visit . Statistical Analysis Data are expressed as the mean ( SD ) with ranges . A P value less than 0.05 was considered significant . On the basis of the assumptions that 15 % of normotensive , normoalbuminuric patients with type 2 diabetes will develop microalbuminuria during 6 years and that treatment with enalapril will reduce the risk for microalbuminuria by 12 % , we calculated that 69 patients were required in each group for a type 1 error of 0.05 and a power of 0.80 [ 21 ] . To test for adequate r and omization and to compare the patients who completed the trial with those who did not complete the trial , the enalapril and placebo groups and the 38 patients who dropped out were compared for mean age ; mean duration of diabetes ; and mean baseline albumin excretion , creatinine clearance , glycosylated hemoglobin value , and blood pressure by using pooled-variance Student t-tests for independent groups and one-way analysis of variance . To compare the annual means of the various measurements between the two groups and within each group , one between-group factor and one repeated- measures factor were used in analysis of variance . For variables shown to be different by analysis of variance , unpaired t-tests were used for between-group parallel annual means and paired t-tests were used for comparison of intragroup sequential annual means . The rate of decrease of creatinine clearance and the rate of increase of albumin excretion were computed by doing linear regression analysis with all of the semiannual values included in the equation . Urinary albumin values were logarithmically transformed before analysis . The degree of albuminuria at baseline was used as a covariate . The funding source had no involvement in the design , conduct , or reporting of the trial . Results Figure 1 shows the flow of participants during the trial . Thirty-eight patients did not complete the trial . Five patients died ( 3 in the enalapril group and 2 in the placebo group ) ; death was related to coronary heart disease in 3 patients , stroke in 1 patient , and ovarian carcinoma in 1 patient . Six patients violated the protocol ( 2 patients in the enalapril group stopped taking their medication for more than 6 months , and 4 patients in the placebo group took an ACE inhibitor prescribed by consultant physicians for more than 6 months ) . Ten patients were lost to follow-up ( 6 in the enalapril group and 4 in the placebo group ) . The trial medication was discontinued in 12 patients : Six developed a disturbing cough ( 4 in the enalapril group and 2 in the placebo group ) , 4 had an allergic skin reaction ( 2 in the enalapril group and 2 in the placebo group ) , 1 patient in the enalapril group developed leukopenia , and 1 patient in the placebo group developed hyperkalemia . Finally , 5 patients developed severe urinary tract infections that had a detectable influence on renal function ( 2 in the enalapril group and 3 in the placebo group ) . A total of 156 patients completed the trial , of whom 77 received enalapril and 79 received placebo . Figure 1 . Flow of participants through the trial . Baseline data for the two groups and for patients who did not complete the trial are shown in Table 1 . The baseline characteristics of patients in the study groups and those who dropped out did not differ significantly . A modest but steady decrease in hemoglobin A1c values was seen in the enalapril and the placebo groups and may reflect the change in attitude toward glucose control among family physicians in the early 1990s . However ,
CONCLUSIONS Antihypertensive treatment reduces the risk of mortality and cardiovascular morbidity in people with diabetes mellitus and a systolic blood pressure more than 140 mm Hg .
If systolic blood pressure is less than 140 mm Hg , however , further treatment is associated with an increased risk of cardiovascular death , with no observed benefit
OBJECTIVE To assess the effect of antihypertensive treatment on mortality and cardiovascular morbidity in people with diabetes mellitus , at different blood pressure levels .