Reducing Morbidity and Mortality in Type 2 Diabetes by Lifestyle Intervention: 30-Year Follow-Up of the Da Qing Diabetes Prevention Study

Background Lifestyle interventions delay the onset of type 2 diabetes in people with impaired glucose tolerance (IGT), but whether this leads subsequently to fewer complications or increases longevity is uncertain. We aimed to determine the long-term effects of lifestyle intervention in people with IGT on the incidence of diabetes, its complications, and mortality. Methods In 1986, 577 adults with IGT in Da Qing, China were randomly assigned by clinic to a control group or one of three interventions (diet, exercise, or diet plus exercise) for six years. Participants were then followed for 30 years to assess the effects of intervention on the incidence of diabetes, cardiovascular events, composite microvascular complications, cardiovascular death, and life expectancy. Findings During the 30-year follow-up, the intervention group, compared with controls, had a median delay of 3·96 years (95% CI, 1·25 to 6·67; P=0·0042) in diabetes-onset with 26% fewer cardiovascular events (hazard ratio, 0·74; 95% CI, 0·59 to 0·92; P=0·0060), 28% lower incidence of severe microvascular complications (hazard ratio, 0·72; 95% CI, 0·52 to 0·99; P=0·044), 33% fewer cardiovascular disease deaths (hazard ratio, 0·67; 95% CI ,0·48 to 0·94; P=0·022), and 26% fewer total deaths (hazard ratio, 0·74; 95% CI, 0·61 to 0·89; P=0·0015), and an average increase of 1·44 life years (95% CI, 0·20 to 2·68; P=0·023). Interpretation Lifestyle intervention in people with IGT delayed the onset of type 2 diabetes, reduced the incidence of cardiovascular events, microvascular complications, cardiovascular and all-cause mortality, and increased life expectancy. The study provides strong justification to continue to implement and expand use of such interventions to curb the global diabetes epidemic and its consequences. Funding: CDC/WHO and CDC/Chinese CDC Cooperative Agreements, World Bank, Ministry of Public Health of the People's Republic of China, Da Qing First Hospital, China-Japan Friendship Hospital, National Center of Cardiology & Fuwai Hospital. Declaration of Interest: No potential conflicts of interest relevant to this article have been reported. Ethical Approval: Institutional review boards at the Chinese Centers for Disease Control and Prevention and Fuwai Hospital approved the study.