Abstract
BACKGROUND: Recent data suggest that sodium (Na(+) ) is stored in the muscle and skin without commensurate water retention in maintenance hemodialysis (MHD) patients. In this study, we hypothesized that excessive Na(+) accumulation would be associated with abnormalities in peripheral insulin action. METHODS: Eleven MHD patients and eight controls underwent hyperinsulinemic-euglycemic-euaminoacidemic clamp studies to measure glucose (GDR) and leucine disposal rates (LDR), as well as lower left leg (23) Na magnetic resonance imaging to measure Na(+) concentration in the muscle and skin tissue. RESULTS: The median GDR and LDR levels were lower, and the median muscle Na(+) concentration was higher in MHD patients compared with controls. No significant difference was found regarding skin Na(+) concentration between group comparisons. Linear regression revealed inverse relationships between muscle Na(+) concentration and GDR and LDR in MHD patients, whereas no relationship was observed in controls. There was no association between skin Na(+) content and GDR or LDR in either MHD patients or controls. CONCLUSIONS: These data suggest that excessive muscle Na(+) content might be a determinant of IR in MHD patients, although the causality and mechanisms remain to be proven.