Lacey B, et al. - A prospective cohort study was performed to examine the age-specific association between blood pressure and vascular and non-vascular chronic diseases among adults in China. Systolic blood pressure was continuously related to major vascular disease with no evidence of a threshold down to 120 mm Hg among adults in China. The findings suggested that blood pressure was more strongly correlated with intracerebral haemorrhage than with ischaemic stroke and even small declines in mean blood pressure at a population level could be expected to have a major impact on vascular morbidity and mortality.

Methods

• Between June 25, 2004, and July 15, 2008, five hundred twelve thousand, eight hundred ninety-one adults (59% women) aged 30–79 years were selected into a prospective study from ten areas of China.
• Members attended assessment centres where they were questioned about demographic and lifestyle characteristics, and their blood pressure, height, and weight were measured.
• After that, incident disease was identified through linkage to local mortality records, chronic disease registries, and claims to the national health insurance system.
• Cox regression analysis was used to produce adjusted hazard ratios (HRs) relating systolic blood pressure to disease incidence.
• To estimate associations with long-term average (usual) systolic blood pressure, HRs were corrected for regression dilution.

Results

• Results revealed that there was 88,105 incident vascular and non-vascular chronic disease events (about 90% of strokes events were diagnosed using brain imaging) during a median follow-up of 9 years (IQR 8–10).
• It was noted that at ages 40–79 years (mean age at event 64 years [SD 9]), usual systolic blood pressure was continuously and positively linked with incident major vascular disease throughout the range 120–180 mm Hg: each 10 mm Hg higher usual systolic blood pressure was correlated with an approximately 30% higher risk of ischaemic heart disease (HR 1·31 [95% CI 1·28–1·34]) and ischaemic stroke (1·30 [1·29–1·31]), but the relationship with intracerebral haemorrhage was about twice as steep (1·68 [1·65–1·71]).
• The authors discovered that HRs for vascular disease were twice as steep at ages 40–49 years than at ages 70–79 years.
• Data reported that usual systolic blood pressure was also positively linked with incident chronic kidney disease (1·40 [1·35–1·44]) and diabetes (1·14 [1·12–1·15]).
• According to the findings obtained, about half of all vascular deaths in China were attributable to elevated blood pressure (ie, systolic blood pressure >120 mm Hg), accounting for approximately 1 million deaths (<80 years of age) annually.