Suggestion of a deficient osteoblastic function in diabetes mellitus: The possible cause of osteopenia in diabetics

Abstract

The mechanism underlying diabetic osteopenia is still unclear and may involve osteoblastic activity and/or the deficit of insulin's anabolic action. Bone gla protein (BGP) is synthesized by the osteoblast and its synthesis increases with 1,25(OH)2D3 and fluoride. Because 1,25(OH)2D3 also stimulates insulin secretion, sodium fluoride administration can be used to investigate deficient osteoblastic activity in diabetics, as reflected by BGP levels. BGP was determined before and after administering sodium fluoride at a dosage of 50 mg/day/15 days to three groups: 14 patients with insulin-dependent diabetes, 16 diabetics on oral antidiabetic treatment, and 25 controls, all of similar age, sex, and characteristics. Basal BGP values (mean +/- SD) were low in diabetics on insulin treatment (4.3 +/- 1.1 ng/ml) and in diabetics on oral antidiabetics (5.8 +/- 1.2 ng/ml) as compared with controls (6.5 +/- 0.7 ng/ml) (P less than 0.001 and less than 0.05, respectively). After giving fluoride, BGP values did not change in the two diabetic groups but did vary in controls (8.1 +/- 0.6 ng/ml, P less than 0.001). These results suggest that deficient osteoblast function could be responsible for osteopenia in diabetics.

Effect of Glycemic Control on Calcium and Phosphorus Handling and Parathyroid Hormone Level in Patients with Non-Insulin-Dependent Diabetes Mellitus.

“…It is not concluded that the decrease in serum total alkaline-phosphatase was due to the change in its iso-enzyme from bone. Low-normal osteocalcin, observed in our diabetic patients, was consistent with previous reports [9,10]. The function of osteoblasts is suppressed in diabetic animals and human patients [7][8][9][10].…”

“…With respect to bone metabolism, histomorphometric studies have shown that bone turnover is low in diabetic animals [7,8]. Also, serum osteocalcin concentrations are low in diabetic animals and human patients [7][8][9][10]. Urinary loss of minerals can be corrected by appropriate blood glucose control [11][12][13], but it remains unclear whether glycemic control has any effect on PTH secretion or bone turnover.…”

Serum osteocalcin concentrations in relation to glucose and lipid metabolism in Chinese individuals

“…Moreover, we found FPG was independently correlated with osteocalcin in men, and HbA1c was independently correlated with osteocalcin in both premenopausal and postmenopausal women. Studies in vivo or in vitro have demonstrated that in hyperglycemic states, the osteoblast mass and possibly function are decreased, which suppresses osteocalcin synthesis and secretion (18,19), resulting in impaired bone turnover and reduced bone formation (20). Conversely, osteocalcin also has an impact on glucose regulation.…”

HMG-CoA Reductase Inhibitors Increase BMD in Type 2 Diabetes Mellitus Patients

“…Hyperinsulinemia and relatively high BMI are protective against bone loss in type 2 diabetes mellitus (16). By comparison, increased calciuria and decreased osteoblastic function due to hyperglycemia may lead to deterioration of bone mass and have been observed in patients with type 2 diabetes mellitus (17,18). In our study, we matched our subjects for fasting plasma glucose, hemoglobin A 1 c levels, and duration of disease.…”