Responses to lifestyle interventions in people with impaired glucose tolerance (IGT) may differ during the intervention phase: some progress to diabetes, some regress to normal glucose tolerance (NGT) and some retain IGT. Whether these different responses to intervention influence subsequent outcomes is uncertain. In 1986, 576 persons with IGT in Da Qing, China, were randomized to control or intervention (diet, exercise, diet plus exercise) groups for a six-year lifestyle intervention. In 1992, of 540 participants who completed the intervention, 252 (46.7%) had progressed to diabetes, 174 (32.2%) regressed to NGT, and 114 (21.1%) remained as having IGT. In 2016, we conducted a 30-year follow-up study to assess the intervention effect on CVD events, defined as the first occurrence of non-fatal or fatal stroke, myocardial infarction or heart failure, and composite microvascular complications, defined as the first occurrence of severe retinopathy, nephropathy or neuropathy. We compared the difference in those outcomes between the three groups. The 30-year cumulative incidence of CVD was 65.6% (95% CI 58.7-71.5) in the participants with diabetes, 46.1% (95% CI 48.0-53.8) in those with NGT, and 50.6% (95% CI 40.5-59.9) in those with IGT. The corresponding incidence of microvascular complications was 44.3% (95% CI 36.8-51.4), 23.1%, (95% CI 15.7-31.4), and 31.2% (95% CI 21.1-41.7). Adjusting for age and sex, those who had developed diabetes had significantly higher risks than those who had reverted to NGT for both CVD (HR = 1.57, 95% CI 1.18-2.07, P = 0.002) and composite microvascular complications (HR = 2.53, 95% CI 1.62-3.93, P < 0.0001). Our results indicate that delaying the development of diabetes in people with IGT is likely to reduce the incidence of both macro and microvascular adverse outcomes.
Y. Chen: None. P. Zhang: None. J. Wang: None. Q. Gong: None. Y. An: None. E. Gregg: None. P.H. Bennett: Consultant; Self; World Health Organization. Stock/Shareholder; Self; Becton, Dickinson and Company, Eli Lilly and Company, Pfizer Inc., UnitedHealth Group Inc. Other Relationship; Self; American Diabetes Association, Centers for Disease Control and Prevention, European Association for the Study of Diabetes, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health. G. Li: None.
Centers for Disease Control and Prevention/Chinese Center for Disease Control and Prevention (5U19GH000636-05)