Table 3_Beyond BMI: independent and opposing effects of overweight and obesity and triglycerides on 90-day functional outcomes after acute ischemic stroke.docx

ObjectiveTo investigate whether the “obesity paradox” in acute ischemic stroke (AIS) is a masking effect of metabolic lipid reserves. We evaluated the independent and opposing associations of body weight status and admission triglycerides (TG) with 90-day functional outcomes to distinguish the structural burden of obesity from metabolic health.
MethodsThis dual-center retrospective cohort study included 571 consecutive AIS patients recruited between 2019 and 2024. Patients were categorized into normal-weight (NW, n = 245; BMI 18.5–23.9 kg/m2) and overweight-or-obesity (OW, n = 326; BMI ≥ 24.0 kg/m2) groups. The primary endpoint was an excellent functional outcome [modified Rankin Scale (mRS) 0–1] at 90 days. Multivariable logistic regression and inverse probability weighting (IPW) were employed to isolate the independent effects of weight status and TG levels.
ResultsAt 90 days, the proportion of patients achieving an excellent outcome was significantly higher in the NW group than in the OW group (60.4% vs. 50.6%; p = 0.020). In univariable analysis, patients who achieved an excellent outcome (mRS 0–1) had significantly higher admission TG levels than those who did not [median 1.33 (IQR 0.97–1.92) vs. 1.13 (IQR 0.90–1.48) mmol/L; p < 0.001]. After adjusting for comprehensive confounders including age, NIHSS, and other lipid profiles, overweight-or-obesity was independently associated with lower odds of an excellent outcome (adjusted OR = 0.611, 95% CI: 0.394–0.945; p = 0.027). Conversely, higher admission TG levels were significantly associated with better recovery (adjusted OR = 1.405 per 1 mmol/L increase, 95% CI: 1.057–1.867; p = 0.019). These opposing associations remained robust in IPW sensitivity analyses.
ConclusionThe “obesity paradox” in AIS appears to be a masking effect driven by TG reserves. Once disentangled from metabolic benefits, overweight and obesity emerge as independent risk factors for poorer recovery. These findings support a phase-specific metabolic management strategy: mitigating the physical and systemic burdens of obesity while ensuring sufficient TG levels within the physiological range to support neural repair during the acute window.