The Impact of Modified Body Mass Index on Clinical Prognosis in the Elderly With Acute Ischemic Stroke.

Objectives: The modified body mass index (mBMI) combines the body mass index and serum albumin, accurately reflecting the nutritional status. It remains uncertain whether modified body mass index influences neurological function and clinical prognosis in elderly patients with acute ischemic stroke.

Methods: We divided the cohort into quartiles of mBMI (1 to 4). The primary outcome was analyzed using the percentage of patients with a 90-day modified Rankin scale (mRS) score of 0 to 1. There were 7 secondary outcomes, including the disability level at 90 days and the National Institute of Health Stroke Scale (NIHSS) score at 14 and 90 days.

Results: mBMI was negatively associated with clinical prognosis at 90-day mRS score in the primary outcome (β=-0.167; 95% CI -0.311 to 0.023, P=0.023). Moreover, mBMI1 (<896.72) and primary outcomes (β=0.438; 95% CI: -0.018 to 0.894) were positively correlated with higher mBMI. Moreover, the number and percentage of patients completing all the duties and activities are also higher. Age-adjusted Charlson comorbidity index (aCCI) and posterior circulation lesion were positively associated with the clinical prognosis 90-day mRS score in the primary outcome (β=2.218; 95% CI: 1.144-4.300, β=2.771; 95% CI: 1.700-4.516). However, BMI and serum albumin were not associated the with clinical prognosis primary outcome. BMI negatively correlates with secondary outcomes (NIHSS at discharge, β=-0.023; 95% CI: -0.102 to 0.057).

Conclusions: Our study revealed that mBMI and not BMI could be a better primary outcome predictor in the elderly with acute ischemic stroke, and lower mBMI showed a worse prognosis.