LoBAG30 Diet in Patients on Metformin (LoBAG Diet)

Metabolic Response to a LoBAG30 Diet in Diabetic Patients on Metformin

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.

Study Overview

• Status: Terminated
• Conditions: Diabetes Mellitus; Diet
• Intervention / Treatment: Other: LoBAG30 diet; Other: Control Diet

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.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Minneapolis, Minnesota, United States, 55417
      • VA Medical Center, Minneapolis

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Arm 1; A LoBAG30, weight maintenance diet will be given to subjects on metformin. All food will be provided for 5 weeks.	Other: LoBAG30 diet; A LoBAG30 diet consists of 30% of total energy intake as carbohydrate, 30% protein, and 40% fat.
Placebo Comparator: Arm 2; A weight maintenance, control diet consisting of 55% carbohydrate, 15% protein, 30% fat will be given to subjects on metformin. All food will be provided for 5 weeks.	Other: Control Diet; A control diet consists of 55% of total energy intake as carbohydrate, 15% protein, 30% fat

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in %Hemoglobin A1c at 5 Weeks From Baseline	Hemoglobin A1c measured before and after 5 weeks on the diet	Baseline and 5 weeks after dietary intervention
Change in Total Glucose Area at 5 Weeks From Baseline	The area response is measured using zero as baseline. The area is measured before dietary intervention, and following 5 weeks of dietary intervention.	Baseline and 5 weeks after dietary intervention
Change in Body Weight at 5 Weeks From Baseline	Subjects were to remain weight stable. We expected less than 2 pound weight change over 5 weeks. Weight was measured before dietary intervention, and after 5 weeks of dietary intervention.	baseline and 5 weeks after dietary intervention
Change in Overnight Fasting Glucose Concentration at 5 Weeks From Baseline	Overnight fasting glucose concentration was measured before dietary intervention and after 5 weeks of dietary intervention.	baseline and 5 weeks after dietary intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microalbumin Excretion	change in urinary albumin excretion was measured before dietary intervention and after 5 weeks of dietary intervention	baseline and 5 weeks after dietary intervention
Change in Fasting Triglycerides at 5 Weeks From Baseline	Overnight fasting triglycerides concentration was measured before dietary intervention and after 5 weeks of dietary intervention	baseline and 5 weeks after dietary intervention

Collaborators and Investigators

• Sponsor: US Department of Veterans Affairs
• Investigators: Principal Investigator: Mary Gannon, PhD, Minneapolis Veterans Affairs Medical Center

Study record dates

Study Major Dates

• Study Start: April 1, 2008
• Primary Completion (Actual): January 1, 2011
• Study Completion (Actual): March 1, 2011

Study Registration Dates

• First Submitted: January 31, 2008
• First Submitted That Met QC Criteria: February 5, 2008
• First Posted (Estimate): February 6, 2008

Study Record Updates

• Last Update Posted (Estimate): December 12, 2014
• Last Update Submitted That Met QC Criteria: December 10, 2014
• Last Verified: December 1, 2014

More Information

Terms related to this study

• Keywords: Diet; Lipids; Glycemic Index; Dietary Protein; Dietary Carbohydrate; Kidney Function; Glycohemoglobin; Diabetes Mellitus (type 2)
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus
• Other Study ID Numbers: CLIN-010-07F