Menopause alters temperature sensitivity of muscle force in humans

Isometric maximum voluntary force (MVF) of the adductor pollicis and first dorsal interosseous muscles was measured in 11 pre- and 11 post-menopausal (Pre-M and Post-M) human subjects. The temperature of the hand varied in the range 18 degrees-38 degrees C by water immersion and skin temperature was recorded. MVF at each temperature was expressed relative to the value at skin temperature above 35 degrees C to give MVFREL. The form of the relation between MVFREL and temperature was different in the Pre-M and Post-M groups (p < 0.01). In the Pre-M group the maximum value of MVFREL occurred near 30 degrees C and force fell at both higher and lower temperatures. In the Post-M group MVFREL showed an approximately linear decline with cooling across the whole temperature range. The maximum value of MVFREL for the Post-M group was near 35 degrees C. The values of MVFREL for the Post-M group were significantly lower than for the Pre-M group at temperatures between 18 degrees and 30 degrees C.