Overweight and obesity are associated with improved survival, functional outcome, and stroke recurrence after acute stroke or transient ischaemic attack: observations from the TEMPiS trial

Abstract

The aim of the study was to evaluate the association of the body mass index (BMI) with mortality and with non-fatal functional outcome in patients with acute stroke or transient ischaemic attack (TIA). Obesity is an established risk factors in primary cardiovascular disease prevention including stroke. The impact of overweight in patients with stroke or TIA on secondary fatal and non-fatal functional outcomes is less well established. Data from 4428 patients with acute stroke or transient ischaemic attack (TIA) from the Telemedical Project for Integrative Stroke Care (TEMPiS) were studied in this post hoc analysis. The body mass index was available in 1521 patients. Patients were categorized as underweight (BMI <18.5), normal (BMI 18.5 to <25) overweight (BMI 25 to <30), obesity (BMI 30 to <35), advanced obesity (BMI ≥35 all kg/m(2)), and no body weight assessed. Outcome measures after 30 months were all-cause mortality and non-fatal outcomes: recurrent stroke, need for institutional care, and functional impairment (Barthel index <60, modified Rankin score >3). Mortality risk was lower in overweight patients [hazard ratio (HR): 0.69, 95% confidence interval (CI): 0.56-0.86) and lowest in obese (HR: 0.50, 95% CI: 0.35-0.71) and very obese patients (HR: 0.36, 95% CI: 0.20-0.66] compared with normal BMI. Functional, non-fatal outcomes, and recurrent stroke followed the same inverse pattern: underweight patients had the worst outcomes but obese patients had better outcomes than patients with normal BMI (all P < 0.01). After adjustment for multiple confounding factors, obese patients had a lower risk of the combined endpoints of death or institutional care (OR: 0.60, 95% CI: 0.38-0.92), death or high dependency (OR: 0.60, 95% CI: 0.39-0.91) and death or recurrent stroke (OR: 0.56, 95% CI: 0.37-0.86). Mortality was significantly lower in obese patients (all BMI >30 kg/m(2)) than patients with normal weight (HR: 0.70; 95% CI: 0.50-0.98). Underweight patients had consistently the highest risks for all endpoints. Overweight and obese patients with stroke or TIA have better survival and better combined outcomes of survival and non-fatal functional status than patients with the BMI <25 kg/m(2).