Relation between adiposity and vascular events, malignancy and mortality in patients with stable cerebrovascular disease.

ABSTRACT

BACKGROUND: Abdominal adiposity is associated with various risk factors including hypertension, and is therefore particularly relevant in patients with stable cerebrovascular disease (CeVD). A U-shaped relation between body mass index (BMI, kg m-2) and cardiovascular events is often described. Whether this U-shape persists for abdominal adiposity, and consequently which reference values should guide clinical practice, is unclear. We described the relation between multiple adiposity measurements and risk of vascular events, vascular mortality, malignancy and all-cause mortality in patients with clinically stable CeVD. METHODS: During a median follow-up time of 6.8 years, 1767 patients were prospectively followed. Relations were assessed using multivariable adjusted Cox proportional hazards models. Adiposity was assessed with BMI, waist circumference (stratified by gender) and the contribution of visceral fat to total abdominal fat (VAT%) measured using ultrasound. Relations were nonlinear if the χ2-statistic of the nonlinear term was significant (P-value<0.05). Nadirs were reported for nonlinear and hazard ratios (HRs) for linear relations. RESULTS: The relations between BMI and outcomes were nonlinear with nadirs ranging between 27.1 (95% confidence interval (CI) 21.9-29.3) kg m2 for vascular mortality and 28.1 (95% CI, 19.0-38.2)) kg m-2 for malignancy. The relation between waist circumference and all-cause mortality was nonlinear with a nadir of 84.0 (95% CI, 18.7-134.8) cm for females and 94.8 (95% CI, 80.3-100.1) cm for males. No nonlinearity was detected for VAT%. A 1-s.d. (9.8%) increase in VAT% was related to both vascular (HR, 1.23, 95% CI 1.00-1.51) and all-cause mortality (HR, 1.22, 95% CI 1.05-1.42). CONCLUSIONS: In patients with CeVD, a BMI around 27-28 kg m-2 relates to the lowest risk of vascular events, vascular mortality, malignancy and all-cause mortality. However, increasing abdominal adiposity confers a higher risk of all-cause mortality. Thus, whereas traditional BMI cutoffs may be re-evaluated in this population, striving for low abdominal obesity should remain a goal.