Obesity decreases all-cause mortality risk in patients with ischemic stroke and malnutrition: A cohort-based study

The mechanism of the obesity paradox remains uncertain, and malnutrition may be one explanation. Thus, we investigated the interaction between body mass index (BMI) and malnutrition on clinical outcomes in patients with ischemic stroke.

Patients included in Minhang Stroke Cohort study were recruited. The patients were categorized as four groups based on BMI. Nutritional status was evaluated by the Controlling Nutritional Status score. All-cause mortality and poor outcome were compared utilizing multivariate logistic regression analyses, restricted cubic splines, and subgroup analyses.

Among the 3160 people included in the study, overweight (OR: 0.65, 95% CI: 0.44-0.94,p = 0.022) and obese patients (OR: 0.51, 95% CI: 0.28-0.90,p = 0.025) showed significantly lower all-cause mortality risk compared with normal weight individuals. In malnourished population, patients with overweight or obesity showed a reduction in the incidence of all-cause mortality, respectively (overweight: OR: 0.51, 95% CI: 0.32-0.81, p = 0.004; obesity: OR: 0.46, 95% CI: 0.20-0.94, p = 0.044), which were not found in nourished patients.

The obesity paradox is present specifically in malnourished patients with ischemic stroke. When treating patients with malnutrition, the improvement of nutritional status may be more beneficial for prolonged survival.