HOUSTON — Introducing a carbohydrate-modified diet, alone or in combination with insulin sensitizers, decreased body weight in normoglycemic and hyperinsulinemic women, according to data from the Enhance the Metabolic Profile of Women with Insulin Resistance study.
“Progressive weight gain starting in the fourth and fifth decades [of life] has been associated with various long-term adverse outcomes that include diabetes, coronary heart disease, all-cause mortality and impaired quality of survival after [age] 40,” Harriette Rosen Mogul, MD, MPH, associate professor of clinical medicine at the New York Medical College in Valhalla, N.Y,, said during her presentation here at the Endocrine Society’s 94th Annual Meeting and Expo. “Preventive interventions targeting high-risk populations are critically needed.”
Therefore, she and colleagues conducted the double blind, placebo-controlled, randomized EMPOWIR trial to determine whether insulin sensitizers (2,000 mg metformin and metformin plus 4 mg rosiglitazone) plus a carbohydrate-modified diet could reduce body weight and alleviate risks for diabetes and related cormorbidities among normoglycemic, hyperinsulinemic women with midlife weight gain.
“Our long-term underlying study hypothesis has been that the identification of hyperinsulinemia, prior to the onset of overt glucose abnormalities, and early initiation of insulin sensitizers could alter the pathogenesis and disease progression in midlife women to provide new treatment models for populations at risk for type 2 diabetes and metabolic syndrome,” Mogul said.
The study included 46 women — mean age, 46.6 years; BMI, 30.5; HbA1c, 5.4% — who were randomly assigned to modified diet alone, modified diet plus metformin or modified diet plus metformin and rosiglitazone (Avandia, GlaxoSmithKline).
Mogul and colleagues compared fasting insulin and glucose, body weight, HOMA, blood pressure, lipids, adiponectin and leptin at baseline and 6 months. They also conducted paired t-tests and used multivariate models.
All participants attended four weekly nutrition workshops where they were introduced to the EMPOWIR dietary intervention, which included a food exchange program of 40% carbohydrates-40% protein-20% fat. The intervention promoted the consumption of vegetables, low-glycemic-index fruits, low-fat protein and dairy with the elimination of free sugars and restriction of three allowable additional starches after 4 p.m.
Mean body weight was significantly reduced in all treatment groups (P=.049; P=.005; P=.017). There were significant reductions in fasting glucose and fasting insulin in the metformin arm only (P=.034 and P=.011). In the metformin alone and metformin plus rosiglitazone groups, HOMA decreased (P=.054 and P=.013). In the metformin alone arm, systolic BP decreased (P=.001).
Adiponectin increased in the metformin plus rosiglitazone arm only (P<.001).
There was no decline in leptin among those who achieved body-weight loss (P=.907).
Based on these results, “easily adopted dietary interventions alone, and in combination with metformin, could have important clinical and public health implications,” she concluded. – by Stacey L. Fisher
For more information:
Mogul HR. Abstract #S18-6. Presented at: the Endocrine Society’s 94th Annual Meeting and Expo; June 23-26, 2012; Houston.
Disclosure: Dr. Mogul is principle investigator for GlaxoSmithKline, and Dr. Feras M. Hantash is study investigator for Quest Diagnostics. All other researchers report no relevant financial disclosures.