Systolic BP linked to cerebrovascular complications irrespective of BMI
MedWire News: Elevated systolic blood pressure (SBP) is associated with an increased risk for cardiovascular disease (CVD), coronary heart disease (CHD), and both ischemic and hemorrhagic stroke, irrespective of body mass index (BMI), suggest study results.
Although the effect of increased BP on CVD risk is weaker in people with relatively high BMI, the difference is not sufficiently great to warrant alterations to existing guidelines, Mark Woodward (University of Sydney, Australia) and colleagues write in Stroke.
The team used data from 419,448 participants aged over 30 years from the Asia Pacific Cohort Studies Collaboration who had baseline SBP and BMI information available.
During 2.6 million person-years of follow-up, 10,877 CVD events occurred. The age and smoking-adjusted hazard ratio for CVD increased continuously with increasing SBP irrespective of BMI category. Indeed, for each 10 mmHg increase in SBP, there was a 34% increased risk for CVD, overall.
Irrespective of how BMI was classified (either according to the World Health Organization [WHO] criteria or by fifths of the population) there was evidence to suggest that this association was slightly but significantly attenuated with increasing BMI, such that the most obese individuals had the lowest CVD risk per unit increase in SBP.
However, the authors explain that because the "magnitude of the interaction is modest," it is unlikely to have major implications for current risk scores.
Compared with individuals who had a normal BMI (18.5-23.0 kg/m2 according to the WHO) and an SBP of less than 120 mmHg, obese individuals (30.0-60.0 kg/m2) with an SBP of at least 160 mmHg had a fourfold increased risk for CVD.
For CHD, ischemic stroke, and hemorrhagic stroke, the overall hazard ratios were 1.24, 1.46, and 1.65 per 10 mmHg increase in SBP.
"These analyses, based on prospective data from >400,000 individuals, demonstrate the strong role of BP in determining future risk of CHD and stroke across all levels of BMI," write the authors.
"We conclude that current hypertension and stroke guidelines do not require modification to allow for an individual's current body size."
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By Piriya Mahendra