The obesity paradox and survivors of ischemic stroke

Although obesity is a risk factor for stroke and achieving normal weight is advocated to decrease stroke risk, the risk associated with obesity and weight loss after stroke has not been well established. The aim of this study was to assess the association of obesity at the time of stroke admission and weight loss after stroke with total mortality.

We analyzed 736 consecutive patients (mean age, 66 ± 11 years; 58% men) hospitalized for their first ischemic stroke. Body weight at hospital admission and at the outpatient visit during follow-up was used in the analysis.

After multivariate adjustment, obesity at admission was associated with lower mortality risk as compared with normal weight (hazard ratio [HR], .50, P = .03). At the outpatient visit, with a median follow-up time of 16 months, 21% of patients had lost more than 3 kg of weight. Stroke severity, heart failure, transient ischemic attack, and depression after stroke were independently associated with significant weight loss. Weight loss of more than 3 kg was associated with increased mortality risk (HR, 5.87; P = .001) independently of other factors. Similar results were seen when weight loss was defined as losing more than 3% of baseline weight (HR, 4.97; P = .004). Weight gain of more than 5% of the baseline weight tended to be associated with better survival when compared with no weight change (log-rank test, P = .07).

Normal weight at hospital admission and weight loss after ischemic stroke are independently associated with increased mortality. Overweight and obesity at baseline do not decrease the risk associated with weight loss.