In the randomized, controlled Look AHEAD trial, an intensive lifestyle intervention (ILI) was associated with partial remission of type 2 diabetes when compared with diabetes education and support (DES).
The study was published in the Dec. 19, 2012, Journal of the American Medical Association. A summary of the study was published in the January ACP DiabetesMonthly. The following commentary by Ma P. Kyithar, MD, and Sean F. Dinneen, MD, FACP, was published in the ACP Journal Club section of the May 21 Annals of Internal Medicine.
The large Look AHEAD trial asked a question of major importance to patients, health care practitioners, and policymakers: Does ILI reduce the incidence of cardiovascular events among obese patients with type 2 diabetes? Look AHEAD found that, compared with DES, ILI did not reduce cardiovascular events. Gregg and colleagues report the results of secondary analyses, some expected (e.g., diabetes remission is more likely among persons with relatively short-duration, compared with longer-duration, type 2 diabetes) and some surprising (e.g., a mean reduction in body weight of almost 9% in year 1 in the ILI group was associated with a complete remission rate of only 1.3%).
Our understanding of the determinants of remission of type 2 diabetes is incomplete, as is our understanding of prevention of type 2 diabetes among persons at risk. An interesting analogy can be drawn between duration of remission (for many Look AHEAD patients the phenomenon was transient) and the controversy around whether lifestyle interventions really prevent, or simply delay, onset of type 2 diabetes. Why does bariatric surgery seem to have a different trajectory of benefit in terms of diabetes remission? What are the relative contributions of improvement in β-cell function, improvement in insulin action, and reduction in liver fat to the effect of ILI on remission? Answering these questions requires further research. In the meantime, the low rate of complete remission and the lack of a statistically significant effect of ILI on major cardiovascular events in Look AHEAD is a setback to the proponents of lifestyle modification (before metformin) in the care pathway for management of type 2 diabetes.