The impact of low-carbohydrate diet on glycemic control in Native Americans

Many studies have shown that a low-carbohydrate diet (LCD) is a safe and effective intervention to improve glycemic control. However, published data are limited regarding the use of carbohydrate restriction in the treatment and prevention of type 2 diabetes mellitus (DM) in the Native Americans, in a real-world clinical practice setting. We evaluated the efficacy of an LCD on 50 obese Native Americans with either type 2 DM or impaired fasting blood glucose (IFG) in a primary care/obesity medicine practice. The primary intervention was an LCD defined as an intake of <20 g of carbohydrates per day. The intervention involved providing an educational handout and behavioral counseling assisted by a dedicated weight loss coordinator. We evaluated the effects of this intervention on hemoglobin A1c, body weight, blood pressure, and lipid parameters. The subjects were evaluated at baseline and 6 months. The subjects underwent additional safety and counseling visits throughout the study. Subjects were considered completers if they had baseline and 6-month measurements. The mean age was 55.0 +/- 10.9 years, and 66.7% were female. Subjects had significant improvements in hemoglobin A1c (-1.4%+/- 0.9%, in subjects with DM, P<0.0001), fasting blood glucose (-15 +/- 4.9 mg/dL, in subjects with IFG, P<0.0001), and body mass index (-4.0 +/- 1.7 kg/m(2), P<0.0001). An LCD can lead to clinically and statistically significant improvement in glycemic control and body weight among obese subjects with type 2 DM or IFG over a 6-month period. The results suggest that carbohydrate restriction can be an effective real-world intervention in a primarily Native American clinical practice. However, further studies are needed to assess long-term compliance and potential weight regain.