The Look AHEAD Trial: bone loss at 4-year follow-up in type 2 diabetes

To determine whether an intensive lifestyle intervention (ILI) designed to sustain weight loss and improve physical fitness in overweight or obese persons with type 2 diabetes was associated with bone loss after 4 years of follow-up. This randomized controlled trial of intensive weight loss compared an ILI with a diabetes support and education (DSE) group among 1,309 overweight or obese subjects. Bone mineral density was assessed at baseline and after 1 year and 4 years of intervention. ILI was effective in producing significant weight loss (5.3% vs. 1.8% in ILI and DSE, respectively; P < 0.01) and increased fitness (6.4% vs. -0.8%) at year 4. In men, ILI participants had a greater rate of bone loss during the first year (-1.66% vs. -0.09% per year in ILI and DSE, respectively). Differences between groups were diminished by one-half after 4 years (-0.88% vs. -0.05% per year in ILI and DSE, respectively) but remained significant (P < 0.01). The difference in rate of hip bone loss between groups over 4 years was related to increased weight loss in ILI. Among women, the rate of bone loss did not differ between ILI and DSE after 4 years. A 4-year weight loss intervention was significantly associated with a modest increase in bone loss at the hip in men but not in women.