Intensive Weight Loss Intervention and Cancer Risk in Adults with Type 2 Diabetes: Analysis of the Look AHEAD Randomized Clinical Trial.

OBJECTIVE: This study was designed to determine whether intensive lifestyle intervention (ILI) aimed at weight loss lowers cancer incidence and mortality. METHODS: Data from the Look AHEAD trial were examined to investigate whether participants randomized to ILI designed for weight loss would have reduced overall cancer incidence, obesity-related cancer incidence, and cancer mortality, as compared with the diabetes support and education (DSE) comparison group. This analysis included 4,859 participants without a cancer diagnosis at baseline except for nonmelanoma skin cancer. RESULTS: After a median follow-up of 11 years, 684 participants (332 in ILI and 352 in DSE) were diagnosed with cancer. The incidence rates of obesity-related cancers were 6.1 and 7.3 per 1,000 person-years in ILI and DSE, respectively, with a hazard ratio (HR) of 0.84 (95% CI: 0.68-1.04). There was no significant difference between the two groups in total cancer incidence (HR, 0.93; 95% CI: 0.80-1.08), incidence of nonobesity-related cancers (HR, 1.02; 95% CI: 0.83-1.27), or total cancer mortality (HR, 0.92; 95% CI: 0.68-1.25). CONCLUSIONS: An ILI aimed at weight loss lowered incidence of obesity-related cancers by 16% in adults with overweight or obesity and type 2 diabetes. The study sample size likely lacked power to determine effect sizes of this magnitude and smaller.

Improving diabetes outcomes through lifestyle change--A randomized controlled trial.

OBJECTIVE: To compare a diabetes group lifestyle intervention (GLI) with dietitian referral for medical nutrition therapy (RD) for weight loss in the usual care setting. METHODS: Randomized clinical trial was conducted with 57 primary care patients with type 2 diabetes and body mass index (BMI) >25 kg/m(2) who received either a dietitian-led 19-week GLI adapted from the Look AHEAD study or RD. Outcome measures include 6-month and 1-year weight loss, changes in medications, glycemic control, cardiac risk factors, and cost analysis. RESULTS: Patients were mean age 61, 59% male, and 32% non-white, and they weighed 97 kg with mean HbA1c 8.2%. At 6 months, 46% of GLI vs. 21% of RD lost ≥5% body weight (P = 0.04), with mean weight loss 6.6 (SD 7.0) kg with GLI and 2.1 (3.5) kg in RD (P = 0.004). HbA1c improved by 0.70 (1.13) vs. 0.39 (1.51) in GLI vs. RD (P = 0.4), respectively, and 82% vs. 38% stopped or reduced diabetes medications (P < 0.001). Weight loss remained significantly greater in GLI compared to RD at 1 year. GLI program cost was $578 per participant. CONCLUSIONS: An affordable GLI achieved significantly more weight loss and medication reduction than RD in primary care patients with type 2 diabetes.