Effect of obesity on functional outcomes at 6？months post-stroke among elderly Koreans: a prospective multicentre study

Objectives We examined whether obesity based on body mass index (BMI) was a predictor of functional independence measure (FIM) at 6？months after ischaemic stroke onset while adjusting for stroke risk factors and covariates and stratifying by age group. Design This is an interim report of the Korean Stroke Cohort for Functioning and Rehabilitation that was designed as a nested case study within a nationwide hospital-based cohort. Setting We identified all patients who were admitted to nine representative hospitals in Korea from 2012 until 2014 under a diagnosis of acute first-ever ischaemic stroke. The hospitals were selected from the metropolitan district, mid-sized cities and a small-sized city. Participants The sample included 2057 patients with acute ischaemic stroke who were at least 18？years old. Primary and secondary outcome measures We divided participants into two age levels (<65 and ≥65？years). Participants were classified into five groups according to their baseline BMI at admission: underweight (BMI<18.5), normal (18.5≤BMI<23), overweight (23≤BMI<25), obese (25≤BMI<30) and extremely obese (30≤BMI). Results The proportion of patients who were aged ≥65？years was 55.0%. The proportions of underweight, normal, overweight, obese and extremely obese patients were 2.6%, 24.3%, 29.6%, 37.2% and 6.3%, respectively, in the <65？years group and 5.5%, 34.5%, 27.9%, 28.8% and 3.3%, respectively, in the ≥65？years group. In a multiple linear regression, the 6-month FIM after stroke in the elderly group was significantly associated with being extremely obese (7.95, p<0.05) after adjusting for confounding variables. In the <65？years group, the 6-month FIM was not associated with any weight category. Conclusions This nationwide hospital-based cohort study showed that extreme obesity is a predictor of a good 6-month FIM, especially in patients with ischaemic stroke who are at least 65？years of age