We investigated the prevalence and risk factors of prehypertension, as well as the predictors of progression from prehypertension to hypertension. To do this, we performed a systematic review and meta-analysis of cross-sectional and longitudinal studies, after unrestricted searches of PubMed and The Cochrane Library through September 2010. In addition, we reviewed references, major textbooks, and review articles. Pooled prevalence, standardized mean differences, and odds ratios were estimated by using a random-effects model.Twenty-six articles met our inclusion criteria; these included 20 cross-sectional and 6 longitudinal studies, with a total sample of 250,741 individuals. The overall pooled prevalence of prehypertension was 36%. The pooled prevalence among males was higher than that among females (40% vs 33%). The pooled standardized mean difference for body mass index was 1.37 (95% confidence interval [CI], 1.20–1.55); for total cholesterol, 8.08 (95% CI, 6.71–9.46); for low-density-lipoprotein cholesterol, 5.14 (95% CI, 3.09–7.18); and for fasting plasma glucose, 4.23 (95% CI, 3.28–5.18); all of which showed more significant results in females. The pooled odds ratio was 1.13 (95% CI, 0.93–1.37) for smoking and 0.98 (95% CI, 0.69–1.39) for drinking. In addition, factors such as older age at baseline, male sex, Mongolian race, and being overweight or obese were predictors of progression to hypertension, according to descriptive analysis.The prevalence of prehypertension was relatively high, especially for males. There were many modifiable risk factors associated with prehypertension, to which healthcare providers should pay more attention.

Background: Prolonged heart rate-corrected QT (QTc) interval has been associated with incident cardiovascular diseases (CVD) in general Western populations. However, this association is unclear in Asian population. We aim to estimate the association between QTc interval and incident CVD in a general Chinese population. Methods: We analyzed 8,867 participants age ≥35 years and free of CVD at baseline in the Northeast China Rural Cardiovascular Health Study. A resting 12-lead electrocardiogram was performed on all participants, and QTc interval computed using the Framingham formula. Cox proportional hazards models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for associations between QTc interval and incident stroke, coronary heart disease, and combined CVD events. Results: Over a median follow-up of 4.66 years, a total of 439 CVD events occurred (298 stroke cases and 152 CHD cases). After full adjustment, prolonged QTc defined by a sex-specific cutoff was associated with increased risk of developing stroke (HR: 1.82, 95% CI 1.20-2.75, P = 0.004) and combined CVD (HR: 1.52, 95% CI 1.05-2.19, P = 0.026). Spline analyses demonstrated no clear thresholds; when modeled as a linear relationship, each 10 ms increase of QTc interval was associated with an HR of 1.12 (95% CI 1.06-1.19, P < 0.001) for stroke and an HR of 1.10 (95% CI 1.05-1.15, P < 0.001) for combined CVD. Baseline QTc interval was not associated with incident CHD with either modeling strategy. Conclusions: Baseline QTc interval is associated with incident stroke and CVD in adults without prior CVD from a general Chinese population.