In this study we tested the hypothesis that an increase in protein content of the diet will
result in an increase in the 24-hour integrated circulating growth hormone (GH) and
insulin-like growth factor-1 (IGF-1) concentrations and an increase in lean body mass in
people with untreated type 2 diabetes.
Subjects with untreated type 2 diabetes were studied using a randomized crossover design.
The study began with an initial two-week observation period. Subjects then were randomly
assigned to one arm of the study for 5 weeks. The carbohydrate:protein:fat ratio for the
control diet is 55:15:30 whereas for the test diet it is 40:30:30. Following a five-week
washout period, subjects were assigned to the other arm of the study. All meals were
provided by the SDTU. A six-day rotating meal plan has been devised. At the beginning and
end of the 5-week diet period, the subject was admitted to the SDTU (Special Diagnostic and
Treatment Unit), was provided with the meals appropriate for the test or control arm of the
study, and had blood drawn at various times during a 24-hour period. In addition to
measurement of GH and IGF-1, IGF-binding proteins 1 and 3, ghrelin, and body composition
- People ages 55 - 75 years old with type 2 diabetes, not receiving oral hypoglycemic
agents or insulin.
- Fasting plasma glucose < 250 mg/dl (<14 mM) (tGHb < 14%).
- Subjects will be screened for hematological abnormalities, liver disease, kidney
disease, macroalbuminuria (>300 mg/24 hours), untreated thyroid disease, congestive
heart failure, angina, life-threatening malignancies, proliferative retinopathy,
diabetic neuropathy, peripheral vascular disease, serious psychological disorders, a
body mass index > 35, and a fasting triglyceride of > 400 mg/dl.
- Presence of any of the above will be considered exclusion criteria.