SAN FRANCISCO — A relatively modest amount of weight loss can normalize fasting plasma glucose and greatly improve insulin sensitivity in people with type 2 diabetes, according to a study reported by Dr. Gerald I. Shulman at the Third World Congress on Insulin Resistance Syndrome.
Eight obese patients with type 2 diabetes achieved these significant improvements after losing an average of just 8 kg (17.6 pounds), equivalent to about 8% of their body weight, said Dr. Shulman of Yale University, New Haven, Conn. Dr. Kitt Falk Petersen was the lead author of the recently published study (Diabetes 2005;54:603–8).
These results have important clinical implications for patients with poorly controlled type 2 diabetes in that a modest weight loss is a psychologically easier goal than achieving normal body weight.
The diabetic patients enrolled in the study began with an average weight of 86 kg and an average body mass index of 30 kg/m
The study diet was a liquid diet formula with 50% carbohydrate, 43% protein, 3% fat, and 12 g of dietary fiber, which was supplemented with raw fruit and vegetables to about 1,200 kcal/day. The patients continued this diet until they achieved euglycemia, which took between 3 and 12 weeks. They were stabilized on an isocaloric diet for 4 weeks before the final metabolic measurements were taken.
Following the diet, the patients weighed an average of 78 kg and had an average BMI of 27.5. Their fasting glucose averaged 6.4 mmol/L, and their fasting insulin averaged 66 pmol/L. All these values represented statistically significant decreases from baseline.
In addition, the patients achieved a marked improvement in glucose responsiveness as measured by a fourfold increase in the glucose infusion rate required to maintain euglycemia during a hyperinsulinemic-euglycemic clamp.
By measuring hepatic glucose metabolism with deuterated glucose, the investigators determined that the weight reduction improved hepatic insulin sensitivity but had no effects on peripheral insulin sensitivity.
