Mechanism of sodium loss with muscle sodium deficiency in sodium supplemented and unsupplemented subjects during hypokinesia.

摘要

BACKGROUND: This study aims at showing the effect of hypokinesia (HK) on sodium (Na+) loss with different muscle Na+ deficiency and different Na+ intake. Muscle Na+ content, plasma Na+ level and Na+ loss with and without Na+ supplementation were measured. METHODS: This study was conducted on 40 healthy male volunteers during a pre-experimental and an experimental period. Subjects were equally divided into four groups: unsupplemented active control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented active control subjects (SACS) and supplemented hypokinetic subjects (SHKS). A daily supplementation of 3.21 mmol of sodium chloride (NaCl) per kg body weight was given to subjects in the SACS and SHKS groups. RESULTS: Muscle Na+ content levels decreased and plasma Na+ levels, and levels of Na+ loss in urine and feces increased (p<0.05) in the SHKS and UHKS groups compared to their pre-experimental values and the values in the respective active control groups (SACS and UACS). However, muscle Na+ content levels decreased more (p<0.05), and plasma Na+ levels and levels of Na+ loss in urine and feces increased more (p<0.05) in the SHKS group than in the UHKS group. CONCLUSIONS: The greater muscle Na+ deficiency with higher than lower Na+ consumption shows that the risk of greater muscle Na+ deficiency is directly related to Na+ consumption. The higher Na+ loss with higher than lower muscle Na+ deficiency shows that the risk of greater muscle Na+ loss is directly related to muscle Na+ deficiency. It is concluded that muscle Na+ deficiency is more evident when Na+ consumption is higher and that muscle Na+ loss was more exacerbated with higher than lower muscle Na+ deficiency indicating that during prolonged HK the muscle Na+ deficiency is due to the inability of the body to use Na+, but not to Na+ shortage in diet.