Association between obesity and mortality after acute first-ever stroke: the obesity-stroke paradox.

Background And Purpose: limited data exist concerning obesity and survival in patients after acute stroke. The objective of this study was to investigate the association between obesity and survival in patients with acute first-ever stroke.

Methods: patients were prospectively investigated based on a standard diagnostic protocol over a period of 16 years. Evaluation was performed on admission, at 7 days, at 1, 3, and 6 months after discharge, and yearly thereafter for up to 10 years after stroke. The study patients were divided into 3 groups according to body mass index (BMI): normal weight (<25 kg/m(2)), overweight (25-29.9 kg/m(2)), and obese (≥ 30 kg/m(2)). Overall survival during follow-up was the primary end point. The secondary end point was the overall composite cardiovascular events over the study period.

Results: based on our inclusion criteria, 2785 patients were recruited. According to BMI, 1138 (40.9%) patients were of normal weight, 1113 (41.0%) were overweight, and 504 (18.1%) were obese. NIHSS score on admission (mean, 11.28 ± 8.65) was not different among the study groups. Early (first week) survival in obese (96.4%; 95% CI, 94.8%-97.9%) and overweight patients (92.8%; 95% CI, 91.2%-94.4%) was significantly higher compared to that of normal-weight patients (90.2%; 95% CI, 88.4%-92.0%). Similarly, 10-year survival was 52.5% (95% CI, 46.4%-58.6%) in obese, 47.4% (95% CI, 43.5%-51.3%) in overweight, and 41.5% (95% CI, 39.7%-45.0%) in normal-weight patients (log-rank test=17.7; P<0.0001). Overweight (HR, 0.82; 95% CI, 0.71-0.94) and obese patients (HR, 0.71; 95% CI, 0.59-0.86) had a significantly lower risk of 10-year mortality compared to normal-weight patients after adjusting for all confounding variables.

Conclusions: based on BMI estimation, obese and overweight stroke patients have significantly better early and long-term survival rates compared to those with normal BMI.