Clinical trial NCT00607867: LoBAG30 Diet in Patients on Metformin
Official title: Metabolic Response to a LoBAG30 Diet in Diabetic Patients on Metformin
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: NA
Conditions: Diabetes Mellitus
Diet
Keywords: Diabetes Mellitus (type 2)
Diet
Glycohemoglobin
Lipids
Kidney Function
Glycemic Index
Dietary Protein
Dietary Carbohydrate
Lead sponsor: VA Office of Research and Development
Sponsor class: FED
First posted: 2008-02-06
Enrollment: 20
Sex: ALL
Minimum age (years): 50
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: We will determine the metabolic response to a Low Biologically Available Glucose Diet (LoBAG30) in subjects currently receiving the maximum dose of metformin as monotherapy in whom the glycohemoglobin is not at an acceptable level (\>8.0%). Our hypothesis is that introduction of a LoBAG30 diet to subjects currently treated with a full therapeutic dose of metformin will improve blood glucose control in people who have not achieved an acceptable total glycohemoglobin on metformin alone.

Detailed description: Subjects will ingest a control diet (55% carbohydrate (CHO), 15% protein, 30% fat) or a LoBAG30 diet (30% CHO, 30% protein, 40% fat) in a parallel design with block randomization in pairs of two. Subjects will return to the study center twice each week while on the diets to have blood glucose, glycohemoglobin, lactate, weight and blood pressure measured, and to have urine assayed for urea and creatinine. At the beginning and end of the 5 week study period, the subjects will be admitted to the study center for 28 hours during which time blood will be drawn for 24 hour profiles of glucose, insulin, other hormones and several metabolites. For those subjects randomized to the LoBAG30 arm of the study, the control diet will be given during the first 24 hour study period; the assigned diet will be given at the end of the 5 week period.

Eligibility criteria: Inclusion Criteria:

* People with type 2 diabetes mellitus who currently are receiving the maximal dose of metformin monotherapy (2500 mg/day).
* These subjects will have had a stable glycohemoglobin (tGHb) in an unacceptably high range (8-11%) for at least 4 months prior to beginning the study.
* Subjects with tGHB \> 11% (HbA1c \> 10%) will not be recruited into the study.

Exclusion Criteria:

* Hematological abnormalities
* liver disease
* kidney disease
* macroalbuminuria (\>300 mg albumin/24 hours)
* untreated thyroid disease
* congestive heart failure
* angina
* life-threatening malignancies
* proliferative retinopathy
* severe diabetic neuropathy
* peripheral vascular disease
* serious psychological disorders
* a body mass index \> 35
* and a fasting triglyceride of \>400 mg/dl.

  * Subjects taking slow-release metformin will not be studied.
  * Subjects taking medications other than metformin, known to affect fuel metabolism such as:
* insulin
* the sulfonylureas
* glucagon-like peptide 1 (GLP-1) analogs and metabolic inhibitors
* pramlintide
* prednisone and similar steroids
* thyroid hormone
* antipsychotic medications
* thiazide diuretics
* medroxyprogesterone
* high dose aspirin, also will be excluded.

  * If concentrations of serum folate, B12 or iron are low, the subject will be excluded from the study until corrected, i.e. until normal concentrations are recorded.

Primary outcomes:
measure: Change in %Hemoglobin A1c at 5 Weeks From Baseline
timeFrame: Baseline and 5 weeks after dietary intervention
measure: Change in Total Glucose Area at 5 Weeks From Baseline
timeFrame: Baseline and 5 weeks after dietary intervention
measure: Change in Body Weight at 5 Weeks From Baseline
timeFrame: baseline and 5 weeks after dietary intervention
measure: Change in Overnight Fasting Glucose Concentration at 5 Weeks From Baseline
timeFrame: baseline and 5 weeks after dietary intervention
Secondary outcomes:
measure: Microalbumin Excretion
timeFrame: baseline and 5 weeks after dietary intervention
measure: Change in Fasting Triglycerides at 5 Weeks From Baseline
timeFrame: baseline and 5 weeks after dietary intervention
Other outcomes:
Locations:
city: Minneapolis
country: United States
facility: VA Medical Center, Minneapolis
state: Minnesota
Study officials:
affiliation: Minneapolis Veterans Affairs Medical Center
name: Mary Gannon, PhD
role: PRINCIPAL_INVESTIGATOR
References: