Determinants of hand grip strength, knee extension strength and functional status in cancer patients

Decreased functionality and muscle weakness are prominent features in cancer patients. We investigated determinants of muscle function assessed by hand grip and knee extension strength as well as functional status in cancer patients.

189 consecutively admitted cancer patients (age 60.8 ± 12.7 years, 96 male) were recruited. Muscle function was assessed by hand grip and knee extension strength, and percentage of anticipated peak expiratory flow (%PEF). Functional status was determined by the EORTC questionnaire of quality of life. Nutritional status was assessed with Subjective Global Assessment (SGA). Age, gender, SGA, body mass index, clinical variables such as cancer location, presence of distant metastases, tumour burden according to TNM stage, UICC stage, number of drugs per day, number of comorbidities, type of treatment and depression were investigated as potential risk factors for muscle weakness and impaired functional status in a multiple regression analysis.

80 patients (39 male) were classified moderately or severely malnourished. Malnutrition also emerged as an independent determinant for hand grip (estimated effect size 11%, p < 0.01), knee extension strength (estimated effect size 12%, p < 0.001), and peak expiratory flow (estimated effect size 30%, p < 0.008) and functional status (estimated effect size 19.4%, p < 0.001) next to age and gender, which were the strongest predictors. Among the disease parameters, only amount of daily medication exhibited a significant influence on knee extension strength.

Malnutrition is a disease independent risk factor for reduced muscle strength and functional status in cancer patients. Treatment of malnutrition might therefore also restore muscle strength.