A 6-year program of diet, exercise, or both helped delay the onset of diabetes in adults, and had significant mortality benefits for women 23 years later, researchers reported online in the Lancet Diabetes & Endocrinology.
The Da Qing Diabetes Prevention Study "is the first to show that lifestyle intervention in people with impaired glucose tolerance can both reduce the incidence of diabetes and decrease mortality," said Dr. Guangwei Li at the China-Japan Friendship Hospital in Beijing and his associates.
They added that the results "provide yet further justification to implement lifestyle interventions for people with impaired glucose tolerance.".
The investigators randomized 577 Chinese adults with impaired glucose tolerance to a control group or to a 6-year intervention program consisting of diet, exercise, or both. The exercise program focused on increasing leisure physical activity, while the diet program promoted weight loss when indicated and reduction of carbohydrate and alcohol intake.
At 23-year follow-up, the intervention group had significantly lower rates of cardiovascular mortality, at 11.9% vs. 19.6%, for a relative risk reduction of 41%; all-cause mortality, at 28.1% vs. 38.4%, for a RRR of 29%; and diabetes, at 72.6% vs. 89.9%, yielding a RRR of 45% (Lancet Diabetes Endocrinol. 2014 [doi: 10.1016/S2213-8587(14)70057-9]).
But the mortality benefit was significant only in women, in whom the risk reductions were 54% and 72% for cardiovascular and all-cause death, respectively, compared with just 3% and 9% in men. The researchers said they could not determine why the mortality benefit was seen primarily in women. Controlling for a higher smoking rate in men did not account for the difference, they said.
The U.S. Centers for Disease Control and Prevention, the World Health Organization, the China-Japan Friendship Hospital, and the Da Qing First Hospital funded the study. The investigators reported that they had no competing interests.