Among patients with impaired glucose tolerance, diet and exercise interventions for 6 years lowered the cumulative incidence of diabetes at 20 years and delayed onset of the disease.
Lifestyle interventions aimed at improving diet and exercise can lower the incidence of diabetes in people with impaired glucose tolerance. No lifestyle intervention has yet been shown to lower diabetes incidence for longer than 4 years after the intervention, or to decrease cardiovascular complications or long-term mortality.
In 1986, investigators in China randomized 577 adults with impaired glucose tolerance (mean age, 45) to one of three lifestyle interventions (diet, exercise, or both) or no intervention for 6 years. After 6 years, the cumulative incidence of diabetes was significantly lower in the combined intervention groups than in the control group (43% vs. 66%). In 1992, all participants were informed of the results, and they resumed routine medical care; in 2006, the authors collected outcome data.
Cumulative diabetes incidence remained significantly lower in the intervention groups than in the control group (80% vs. 93%). Body-mass index, blood pressure, and cholesterol levels remained similar in the two groups throughout the study. The incidences of first adverse cardiovascular events, cardiovascular mortality, and all-cause mortality were lower in the intervention groups than in the control group, but the study was not powered to demonstrate statistical significance for these outcomes.
Comment: The interventions were group-based and inexpensive. Whether they had lasting effects on local healthcare practices, individual behaviors, or patient metabolism is unclear. Regardless, the increasing global burden of diabetes demands further study of any potentially effective long-term preventive measures.
— Bruce Soloway, MD
Published in Journal Watch General Medicine June 26, 2008
Li G et al. The long-term effect of lifestyle interventions to prevent diabetes in the China Da Qing Diabetes Prevention Study: A 20-year follow-up study. Lancet 2008 May 24; 371:1783.