Objective: It has been reported that glucose intake creates changes at the levels of some electrolytes in serum and urine. The most important change observed in urine is the increase in calcium levels and this is thought to be the result of increased insulin levels in response to glucose rise. In addition to glucose and insulin, it is wondered how parathormone levels fluctuate during these changes. Our aim was to investigate the changes in electrolytes related with bone metabolism in plasma and urine after oral glucose load.

Materials and Methods: Eightteen healthy male aged between 21-64 years were included in this study. Fasting and 15, 30, 45, 60, 90, 120, 180. minutes venous blood was taken after a 75 gram oral glucose load. Glucose, calcium, phosphorus, magnesium, creatinine, insulin and parathormone levels were determined in plasma samples. Calcium, phosphorus, magnesium and creatinine levels were determined in urine samples at the same time. Wilcoxon test was performed to compare the values obtained at 15, 30, 45, 60, 90, 120, 180. minutes with baseline values by using SPSS 11.0 statistics program.

Results: In three hour period after oral glucose load, a non significant increase (p>0.0.5) at 45th minute and then a decline in plasma calcium levels and a rise in urine calcium/creatinine level which was maximum at the 90th minute was determined. There was a decline in urine phosphorus levels which was in parallel with plasma phosphorus levels. The decrease in plasma magnesium level until 60th minute was significant (p<0.05). Urine magnesium/creatinine level decreased until 30th minute and then began rising. After a fall at 15th minute, an increase was observed in parathormone, similar to glucose and insulin peaks.

Conclusion: The changes in calcium and phosphorus levels after glucose load was thought to be related with their second messenger roles in signal transduction pathways.