Weight Change, Lifestyle, and Mortality in Patients With Type 2 Diabetes.

Context: The association between weight change and mortality among participants with incident type 2 diabetes (T2D) was unclear.

Objective: To examine above association and evaluate the impact of lifestyle on it.

Methods: This prospective analysis included 11 262 incident T2D patients from Nurses' Health Study and Health Professionals Follow-up Study. We assessed weight change bracketing T2D diagnosis in relation to mortality. We also examined potential effect modification by a healthy lifestyle consisting of high-quality diet, regular physical activity, nonsmoking status, and moderate alcohol consumption.

Results: On average, T2D patients lost 2.3 kg during a 2-year time window spanning the T2D diagnosis, and body weight increased afterwards following a trajectory similar to that of nondiabetics. Compared with patients with a stable weight, T2D patients who lost ≥10% body weight had a 21% (95% CI, 9%-35%) increased all-cause mortality. Lifestyle significantly modified these associations: the hazard ratios (95% CIs) of all-cause mortality comparing ≥10% weight loss with stable weight were 1.63 (1.26-2.09) among participants with a deteriorated lifestyle, 1.27 (1.11-1.46) for a stable lifestyle, and 1.02 (0.81-1.27) for an improved lifestyle (Pinteraction < 0.001). Major weight loss was associated with increased cause-specific mortality and similar effect modifications by lifestyle were also observed.

Conclusion: Significant weight loss upon T2D incidence was associated with increased mortality, although improved lifestyle quality abolished these associations. These results highlight the role of adopting a healthy lifestyle for newly diagnosed T2D patients, especially among those who might lose weight unintentionally, and improving long-term survival.