Prognostic nutritional indices and functional outcome in patients with subarachnoid hemorrhage: a meta-analysis

Malnutrition is a prevalent but often overlooked factor influencing neurological recovery in patients with subarachnoid hemorrhage (SAH). Nutritional indices such as the Prognostic Nutritional Index (PNI), Controlling Nutritional Status (CONUT) score, and Geriatric Nutritional Risk Index (GNRI) have been proposed as prognostic markers, yet their association with functional outcomes in aSAH remains unclear.

We conducted a meta-analysis of observational cohort studies evaluating the relationship between malnutrition-defined by low PNI, high CONUT, or low GNRI at admission-and poor functional outcome, defined as modified Rankin Scale ≥ 3 or Glasgow Outcome Scale ≤ 3. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using a random-effects model by incorporating the influence of heterogeneity.

Six studies comprising seven datasets and 1,048 patients were included. Malnutrition was significantly associated with increased odds of poor functional outcome (OR: 1.64; 95% CI: 1.24-2.16; I² = 59%). Subgroup analyses showed consistent associations across PNI (OR: 1.38), CONUT (OR: 2.01), and GNRI (OR: 1.61; p for subgroup difference = 0.24). Stronger associations were observed in studies with ≥ 40% men (OR: 3.07) compared to those with < 40% men (OR: 1.43; p for subgroup difference = 0.04), and in studies with 3-month follow-up (OR: 3.55) compared to those assessing outcomes at discharge (OR: 1.31) or 6 months (OR: 1.32; p for subgroup difference = 0.003).

Admission malnutrition, as identified by nutritional indices, was associated with poor functional outcomes in patients with aneurysmal SAH.