Influence of acute experimental hypercalcemia on peripheral insulin sensitivity in healthy subjects

Since hypercalcemia is thought to have a modifying effect on glucose metabolism, the possible influence of experimental hypercalcemia on peripheral insulin reaction was investigated in 6 healthy control subjects by the euglycemic clamp technique. Each of these subjects was randomly tested twice, in the normocalcemic as well as in the hypercalcemic state (infusion of calcium gluconate 15 mg/kg body wt. over a period of 180 min). Infusion of calcium gluconate caused a 27% increase in plasma calcium levels, whereas the plasma phosphate levels were not significantly changed during the eucalcemic and hypercalcemic clamp protocol. Steady state plasma insulin levels and plasma glucose levels were nearly identical between the 2 clamp protocols. Exogenous hypercalcemia had no significant influence on peripheral glucose utilization measured by the M-value (M = 4.83 +/- 0.6 mg/kg body wt./min in the eucalcemic state, 4.77 +/- 0.7 mg/kg body wt./min in the hypercalcemic state, n.s.). The present data indicate that at least acute experimental hypercalcemia has no significant influence on peripheral glucose utilization.