Stroke outcomes in patients with obesity undergoing recanalization therapy

Background The influence of obesity on stroke outcomes remains controversial. Some studies suggest a phenomenon known as the “obesity paradox”, where patients with obesity may recover better. This study investigated the association between obesity and functional outcomes in acute ischemic stroke (AIS) patients undergoing recanalization therapy. Methods The ISOT Study was a prospective cohort study conducted at two comprehensive Stroke Centers in Switzerland between 01/2016 and 09/2021. The study enrolled patients treated with intravenous thrombolysis (IVT) and/or endovascular therapy (EVT) who were functionally independent prior to AIS (modified Rankin Scale [mRS] 0–2). Patients were classified into three weight groups: normal weight (BMI < 25 kg/m²), overweight (BMI 25.0–29.9 kg/m²), and obesity (BMI ≥ 30 kg/m²). Functional outcome was assessed after 3 months and 1 year. Logistic regression analyses adjusted for age and sex were performed. Results Of the 271 patients enrolled (median age 70 years, 65% male, median NIHSS 5 [interquartile range 3–11]), 153 (56%) were treated with IVT, 56 (21%) with EVT and 62 (23%) with IVT + EVT). A total of 96 (35%) had normal weight, 113 (42%) were overweight and 62 (23%) had obesity. Obesity, when compared to normal weight, was associated with poor functional outcomes (mRS 3–6) at three months (24% vs 12%, p = 0.03; adjusted Odds Ratio [aOR] 2.82, 95% confidence interval [CI] 1.16–6.88). At 1 year there was still a trend toward poorer outcomes (aOR 2.50, 95% CI 0.98–6.34). There was no difference between patients with normal weight and those who were overweight. Conclusion In this prospective cohort study, obesity was associated with worse functional outcomes at 3 months with a persistent trend at 1 year in AIS patients undergoing recanalization therapy. These findings provide exploratory, preliminary, hypothesis-generating evidence against the theory of the “obesity paradox” and warrant confirmation in larger cohorts.