Plasma 25-hydroxycholecalciferol in oral sulfonylurea treated diabetes mellitus.

In oral sulfonylurea treated diabetics, decreased plasma 25-hydroxycholecalciferol and increased activity of bone isoenzyme of serum alkaline phosphatase and urinary hydroxyproline excretion was found when compared with control subjects. In stepwise regression analysis significant relationships were found between bone isoenzyme, urinary hydroxyproline excretion, serum calcium levels and blood glucose levels. The partial correlation and multivariate regression analysis showed that in oral sulfonylurea treated patients, but not in insulin treated patients, the activity of bone isoenzyme of serum alkaline phosphatase was significantly inverse dependent on the 25-hydroxycholecalciferol levels in plasma. Oral sulfonylurea agents which are known to induce the hepatic microsomal system seem to be an additional factor to poor control of diabetes, leading to osteopathy.