Correlation between grip strength Z-scores and L3-L4 psoas muscle area Z-scores in pediatric intracranial germ cell tumor patients: A prospective cohort study.

BACKGROUND

In pediatric cancer populations, sarcopenia has received increasing attention as a significant clinical concern. Grip strength measurement has emerged as a potential marker for evaluating muscle function, yet its relationship with total psoas muscle area (tPMA) measurements remain underexplored in pediatric intracranial germ cell tumor (iGCT) patients. This study aimed to investigate the association between grip strength z-scores and psoas muscle cross-sectional area at L3-L4 level.

MATERIAL AND

METHODS

In this prospective cohort study, 108 pediatric iGCT patients underwent grip strength measurement using a calibrated Jamar dynamometer and L3-L4 psoas muscle cross-sectional area assessment via MRI. Measurements were converted to age- and sex-specific z-scores. Primary analyses used multivariable linear regression with tPMA z-score as the continuous outcome and grip strength z-score as the exposure. Tertile analyses were prespecified for clinical interpretability and non-linearity probing and are reported as sensitivity estimates in the tables. ROC analyses were conducted as a secondary assessment of diagnostic performance for abnormal tPMA (z-score < -2 SD).

RESULTS

Each standard deviation increase in grip strength z-score was significantly associated with a 0.43 standard deviation increase in psoas muscle area z-score (95 % CI: 0.30-0.55; p < 0.0001) after adjustment for confounders. Receiver operating characteristic (ROC) analysis revealed moderate diagnostic accuracy of grip strength (AUC = 0.755; 95 % CI: 0.647-0.863) for identifying abnormal psoas muscle area (defined as z-score < -2 SD).

CONCLUSIONS

Grip strength measurement correlates significantly with psoas muscle status in pediatric iGCT patients, offering a simple, non-invasive screening tool for early identification of muscle loss risk in this vulnerable population.