Higher blood pressure predicts diabetes and enhances long-term risk of cardiovascular disease events in individuals with impaired glucose tolerance: Twenty-three-year follow-up of the Daqing diabetes prevention study

Background Hypertension is more prevalent in subjects with impaired glucose tolerance (IGT), but whether higher blood pressure per se or the mild hyperglycemia in combination with the hypertension enhanced the risk of cardiovascular disease (CVD) remains unclear. Methods Five hundred and sixty-eight participants with IGT in the original Daqing diabetes prevention study, 297 with hypertension (HBP) and 271 without hypertension (NBP), were enrolled in 1986 and the intervention phase lasted for 6 years. In 2009, they were followed up to assess the outcomes of cardiovascular events (including stroke and myocardial infarction) and incidence of diabetes. Results Over 23 years, the incidence of diabetes was 93.9/1000 person-years in HBP and 72.2/1000 person-years in the NBP group, with an age- and sex-adjusted hazard ratio of 1.26 (95% confidence interval [CI], 1.04-1.54, P = 0.02). The yearly incidence of CVD events was 27.7/1000 person-years and 16.6/1000 person-years, indicating a 35% higher risk in HBP than in the NBP group (95% CI, 1.01-1.81; P = 0.04). Cox proportional hazard analysis showed that a 10-mm Hg increase of the baseline systolic blood pressure was associated with 9% increased risk of the development of diabetes (P = 0.02), together with a 7% higher risk of the CVD events (P = 0.02). Conclusions Hypertension predicted diabetes and enhances long-term risk of CVD events in patients with IGT. An individualized strategy that targets hypertension as well as hyperglycemia is needed for diabetes and its cardiovascular complications.