METABOLIC IMPROVEMENT OF POORLY CONTROLLED NONINSULIN-DEPENDENT DIABETES-MELLITUS DECREASES BONE TURNOVER

Patients with poorly controlled noninsulin dependent diabetes mellitus (NIDDM) are shown to have higher bone mass. However, the influence of changes in glycemic control on bone turnover is not known. To clarify whether metabolic improvement of poorly controlled NIDDM affects bone turnover, markers for glucose, mineral, and bone metabolism were asse ssed before and after glycemic control for 3 weeks in 78 poorly contro lled NIDDM patients with initial hemoglobin Ale over 8%. Metabolic imp rovement caused a reduction in urinary calcium (Ca) and phosphate (Pi) and serum 1,25(OH)(2)D levels, and an increase in serum Pi without ch anges in serum Ca or parathyroid hormone levels. Bone resorption marke rs, urinary deoxypyridinoline (Dpd) and type I collagen carboxy-termin al telopeptide (CTx), as well as a bone formation marker, serum bone t ype alkaline phosphatase (BALP), were reduced. However, another bone f ormation marker, serum osteocalcin (OC), was low before treatment and was elevated after treatment. The decrease in Dpd, CTx and BALP, but n ot the increase in OC, correlated with each other and with the improve ment in glycemic indices. In conclusion, metabolic improvement of poor ly controlled NIDDM decreases bone turnover within a short period. Thu s, glycemic control may protect NIDDM patients from bone loss. It is p ossible that serum OC is affected by hyperglycemia per se, and may not correctly reflect bone turnover.