Obesity paradox and functional recovery in first-ever acute ischemic stroke survivors: the PREMIER study

Introduction. The 'obesity paradox' is the decreasing risk of death after cardiovascular disease, with a high body mass index (BM!), even when BMI is a risk factor for vasculopathy, in the first place. Our aim was to analyze the influence of obesity on the functional recovery after ischemic stroke. Patients and methods. We studied 510 patients who survived a first-ever acute ischemic stroke, without cerebrovascular disease history, and without recurrence or death after 12 months of follow-up. We also studied 501 healthy subjects who received tetrapolar bioimpedance analysis to compare the waist-to-height ratio (WHtR), abdominal circumference and BMI, as adiposity indices, in order to apply them in stroke patients. Results. In healthy individuals, WHtR performed better than BMI or abdominal circumference in predicting body fat. In a Cox proportional hazards model adjusted for multiple covariables, age (hazard ratio, HR = 1.11; 95% confidence interval, 95% Cl = 1.08-1.14), NIHSS score (HR = 1.03; 95% Cl = 1.01-1.05) and WHtR > 70 (HR = 2.44; 95% Cl = 1.33-4.48) were associated with a high risk of attaining a modified Rankin scale more or equal than 3 at 12 months after stroke; whereas BMI > 35 (HR = 0.33; 95% Cl = 0.11-0.98) was protector. Conclusion. As reflected by WHtR, the excess of adiposity increases the chance of severe disability after ischemic stroke. Since BMI reflects also total lean mass, it is risky to conclude that there is a protective effect of obesity alone in the functional recovery after stroke; nevertheless, it is possible that a certain magnitude of body mass is necessary to prevent severe disability in stroke survivors.