Overweight or obesity increases the risk of cardiovascular disease among older Australian adults, even in the absence of cardiometabolic risk factors: a Bayesian survival analysis from the Hunter Community Study.

Abstract

To estimate the risk of cardiovascular disease (CVD) in older adults with overweight or obesity without metabolic risk factors using a Bayesian survival analysis. Prospective cohort study with median follow-up of 9.7 years. Newcastle, New South Wales, Australia. A total of 2313 community-dwelling older men and women. Participants without known CVD and with a body mass index (BMI) ≥ 18.5 kg m2 were stratified by BMI and metabolic risk to create six BMI-metabolic health categories. Metabolic risk was defined according to the International Diabetes Federation criteria for metabolic syndrome. 'Metabolically healthy' was defined as absence of metabolic risk factors. Bayesian survival analysis, incorporating prior information from a previously published meta-analysis was used to assess the effect of BMI-metabolic health categories on time from recruitment to CVD. Incident physician-diagnosed CVD, defined as fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, angina, or coronary revascularisation procedure, was determined by linkage to hospital admissions records and Medicare Australia data. Secondary outcomes were cardiovascular mortality and all-cause mortality. From 2313 adults with complete metabolic health data over a median follow-up of 9.7 years, 283 incident CVD events, 58 CVD related deaths and 277 deaths from any cause occurred. In an adjusted Bayesian survival model of complete cases with informative prior and metabolically healthy normal weight as the reference group, the risk of CVD was increased in metabolically healthy overweight (HR = 1.52, 95% credible interval 0.96-2.36), and in metabolically healthy obesity (HR = 1.86, 95% credible interval 1.14-3.08). Imputation of missing metabolic health and confounding data did not change the results. There was increased risk of CVD in older adults with overweight or obesity, even in the absence of any metabolic abnormality. This argues against the notion of 'metabolically healthy' overweight or obesity.