Endocrine Abstracts

Fragile bone fractures due to deteriorating bone quality are increased in patients with type 2 diabetes mellitus. This study aimed to measure serum levels of pentosidine and adipocytokines, e.g. adiponectin and leptin, and compare between those biochemical markers and bone mineral density of lumber in patients with type 2 diabetes mellitus. Serum concentration of adiponectin, leptin and pentosidine was measured in 19 type 2 diabetic patients (mean age 65.9+2.3 years) and 13 normal controls (mean age 67.6+3.1 years). Lumber mineral density was measured by dual-energy X-ray absorptiometry. Moreover, serum tartrate-resistant acid phosphatase 5b (TRAP-5b) and procollagen -1 N-terminal telopeptide (P1NP) were measured. Serum concentration of pentosidine was increased in type 2 diabetic patients. However, serum adiponectin and leptin levels were significantly decreased in type 2 diabetic patients as compared with normal control (P<0.01). Moreover, bone mineral density of lumber and serum concentration of TRAP-5b and P1NP were tendentiously decreased in type 2 diabetic patients compared with normal control. Especially, bone mineral density of lumber was significantly reduced in type 2 diabetic patients with lumbar bone fractures (P<0.05) and serum concentration of pentosidine was strongly increased in type 2 diabetic patients with lumbar bone fractures (P<0.01). We have investigated the relationship between bone mineral density and biochemical marker of adipocytokines and bone turnover in type 2 diabetic patients. Several investigators have reported that both adiponectin and leptin stimulated the osteoblastic activity and suppressed the osteoclastic activity, suggesting that low concentrations of adipocytokines lead to diminish bone mineral density. Our data have presented that lumbar bone mineral density, adiponectin, leptin and P1NP in type 2 diabetic patients were lower than those in normal control. In contrast, the pentosidine is reported to reduce bone quality, and to induce a bone fracture. In conclusion, high concentration of pentosidine and low concentration of adipocytokines might induce osteoporosis and fragile lumbar bone fractures in type 2 diabetes mellitus.