Influence of a diet and/or exercise intervention on long‐term mortality and vascular complications in people with impaired glucose tolerance: Da Qing Diabetes Prevention Outcome study

AIM: We aimed to investigate the long-term influence of a diet and/or exercise intervention on long-term mortality and cardiovascular disease (CVD) events. METHODS: The Da Qing Diabetes Prevention Study had 576 participants with impaired glucose tolerance (IGT) randomized to diet-only, exercise-only and diet-plus-exercise intervention group and control group. The participants underwent lifestyle interventions for 6 years. The subsequent Da Qing Diabetes Prevention Outcome Study was a prospective cohort study to follow-up the participants for up to 24 years after the end of 6-year intervention. In total, 540 participants completed the follow-up, while 36 subjects lost in follow-up. Cox proportional hazards analysis was applied to assess the influence of lifestyle interventions on targeted outcomes. RESULTS: Compared with controls, the diet-only intervention in people with IGT was significantly associated with a reduced risk of all-cause death [hazard ratio (HR) 0.77, 95% confidence interval (CI) (0.61-0.97)], CVD death [HR 0.67, 95% CI (0.46-0.97)] and CVD events [HR 0.72, 95% CI (0.54-0.96)]. The diet-plus-exercise intervention was significantly associated with a decreased risk of all-cause death [HR 0.64, 95% CI (0.48-0.84)], CVD death [HR 0.54, 95% CI (0.30-0.97)] and CVD events [HR 0.68, 95% CI (0.52-0.90)]. Unexpectedly, the exercise-only intervention was not significantly associated with the reduction of any of these outcomes, although there was a consistent trend towards reduction. CONCLUSIONS: A diet-only intervention and a diet-plus-exercise intervention in people with IGT were significantly associated with a reduced risk of all-cause death, CVD death and CVD events, while an exercise-only intervention was not. It suggests that diet-related interventions may have a potentially more reliable influence on long-term vascular complications and mortality.