The effect of starvation on skeletal muscle function in man

Measuring skeletal muscle function may be a diagnostic aid to detect malnutrition. To evaluate this hypothesis 11 lean women were studied before and after 5 days of total starvation. Skeletal muscle function was assessed as hand grip strength and as adductor pollicis muscle function after electrical stimulation of the ulnar nerve. The muscle function variables were force of contraction at 5, 10, 20 and 50 Hz stimulation, relaxation rate and endurance. In addition some currently used anthropometric and biochemical nutritional indices were serially determined. Hand grip strength was decreased (p < 0.05) and the function of the adductor pollicis muscle was altered with a higher contraction force at 10 Hz (p < 0.01), a slower relaxation rate (p < 0.05) and a reduced endurance (p < 0.05). These changes were all within the normal ranges. Triceps skin fold and arm muscle circumference were not changed after a mean weight loss of 3.3 kg (p < 0.05). However blood glucose, insulin and triiodothyronine all decreased (p < 0.01) indicating a metabolic adaptation to starvation. Prealbumin (p < 0.05) and fibronectin (p < 0.01) were also lowered. In conclusion, skeletal muscle function was significantly altered after five days of total starvation. However, to identify short term nutritional depletion in clinical practice the changes in muscle function were too small to be diagnostically useful.