Phase angle is associated with nutritional risk in subacute stroke patients at the beginning of rehabilitation

Malnutrition in stroke is associated with poor clinical outcomes. Bioelectrical impedance analysis-derived phase angle (PhA) is widely used for assessing nutritional status as an index of muscle quality. This study aimed to evaluate the associations between whole body and limb PhAs and nutritional risk in stroke patients. PhA predictors were also identified.

Consecutive subacute stroke patients aged ≥50 y at the beginning of rehabilitation participated in this retrospective analysis. Nutritional risk was assessed using the Geriatric Nutritional Risk Index, the Prognostic Nutritional Index, and the Controlling Nutritional Status score. PhAs at 50 kHz for both whole body and limbs were measured. The associations between PhA and nutritional risk were examined through univariate/multivariate analyses.

Overall, 272 subacute stroke patients were studied (age, 70.1 ± 12.4 y, body mass index, 26.8 ± 3.9 kg/m²). Both whole body and limb PhAs were associated with Geriatric Nutritional Risk Index, Prognostic Nutritional Index, and Controlling Nutritional Status score, and this was also true in patients aged ≥75 y (P < 0.001). Low PhA values were observed in patients at high nutritional risk. The general linear model identified age, female sex, hypertension, diabetes, dysphagia, and time from stroke onset as independent predictors of PhA (R² = 0.468, P < 0.001). Furthermore, PhA emerged as a significant predictor of high nutritional risk according to each screening tool. Finally, optimal cutoffs of whole body PhA for predicting high nutritional risk were around 4.08°.

In stroke patients, low PhA values were associated with high nutritional risk. PhA at the beginning of rehabilitation may serve as a reliable parameter to be considered in the evaluation of nutritional status.