Early reductions in weight, glycemic levels improved 3-year diabetes risk
Patients with pre-diabetes who lost 10% or more of their body weight within the first 6 months of their diagnosis reduced their 3-year risk for developing diabetes by 85%, according to a review of the multicenter Diabetes Prevention Program.
“We have known for some time that the greater the weight loss, the lower your risk of diabetes,” Nisa Maruthur, MD, MHS, study researcher and assistant professor in the division of general internal medicine at The Johns Hopkins University School of Medicine, said in a press release. “Now we understand that we can see much of the benefit of losing that weight in those first 6 months when people are adjusting to a new way to eating and exercising.”
The 3,041 participants with hyperglycemia were randomly assigned to intensive lifestyle modification (n=1,108), metformin (n=1,036) or placebo (n=987). Those in the lifestyle arm participated in individual counseling for 6 months, followed by group counseling. The goals of the intervention were at least 150 minutes of moderate-intensity physical activity per week and an overall 7% or more reduction in weight.
Participants in the metformin group received 850 mg daily and those in the control group took placebo twice daily. Both groups participated in annual lifestyle counseling sessions.
At 6-month follow-up, 92% of the lifestyle group lost a mean weight of 7.2%; more than 25% of the metformin group lost a mean of 2.4%; and nearly 50% of the placebo group gained weight, with a mean loss of 0.4%.
In the lifestyle group, each percentage of weight loss at 6 months resulted in a 10% decrease in risk for diabetes (HR=0.9; 95% CI, 0.87-0.94), with participants who lost 10% or more of their body weight at an 85% lower risk for developing diabetes within 3 years. Weight loss was associated with lowered diabetes risk in the placebo arm (HR=0.95; 95% CI, 0.92-0.98), but not in the metformin arm (HR=0.98; 95% CI, 0.94-1.02).
Differences in fasting glucose and HbA1c were not statistically different across the arms. In the lifestyle arm, fasting glucose less than 100 mg/dL indicated a lower 3-year risk for diabetes. Those with a fasting glucose of at least 110 mg/dL, yet who still lost weight, decreased their risk for diabetes (P=.038).
At 12 months, post-load glucose was significantly lower in the lifestyle arm than the placebo and metformin arms. Post-load glucose of less than 140 mg/dL was associated with a 62% to 70% lower risk for diabetes. In the metformin arm, post-load glucose levels predicated diabetes risk independent of weight loss.
Participants with incident diabetes (n=61 at 6 months; n=198 at 12 months) were excluded from the analyses.
“Our results suggest that both the weight loss and glycemic status achieved at 6 months are indicators of long-term success in diabetes prevention,” researchers wrote.