The impact of body-mass-index on functional outcomes and bleeding volumes in patients suffering spontaneous intracerebral haemorrhage

The association between obesity and clinical as well as radiological outcomes in patients suffering spontaneous intracerebral haemorrhage (ICH) remains unclear. The obesity paradox suggests a protective effect regarding in-hospital mortality. This study evaluates the impact of body mass index (BMI) on functional long-term outcome and bleeding volume in patients with spontaneous ICH.

A retrospective cohort study including all patients with spontaneous ICH between December 2017 and June 2021, aged 80 years or younger (n = 218), were included. Patients were dichotomized into overweight (OW, BMI ≥ 25 kg/m²) and normal weight (NW, BMI < 25 kg/m²). Functional outcomes were assessed at 1, 3, 6 and 12-months follow-up. To address potential sex-related bias, we conducted exploratory post hoc analyses.

Of 218 patients (66.04 ± 15.18 years) suffering spontaneous ICH, 115 (52.75 %) were OW (29.72 ± 3.82). Multivariate analysis revealed that independent significant predictors of a favourable 12-month functional outcome were smaller haematoma volume (p = 0.01) and symptom onset less than 6 h before arrival at our hospital (p = 0.018), whereas BMI was not, whether analysed dichotomously, continuously, or by WHO categories (p ≥ 0.41). Younger age showed to be a significant predictive factor for a better 12-month outcome in univariate analyses (p = 0.003), but lost significance in multivariate analyses (p = 0.14). Sex distribution (n = 72 females, n = 68 males; p = 1.0), NIHSS at admission (p = 0.69) and overweight prevalence (41.7 % vs. 55.9 %; p = 0.13) did not differ significantly between groups. Stratified BMI-outcome associations remained non-significant in both sexes (p = 0.39 for males, p = 0.21 for females).

Our data suggests that in patients suffering from spontaneous ICH, haematoma volume and age, are independent negative predictors for functional outcome in the long-term. BMI was not associated with 12-month outcome after adjustment, while early presentation (within 6 h of symptom onset) predicted favourable 12-month outcome.