A Prospective Cohort Study:Forecast Fracture Risk With a Serum Marker of Type 2 Diabetes in Guangzhou Community

Inclusion Criteria: * (1) aged 18-65 years; (2) patients were diagnosed with type 2 diabetes based on the definition of diabetes of WHO in 1999. Exclusion Criteria: * 1\. type 1 diabetes and other specific types of diabetes; 2. diabetes related acute complications like diabetic ketoacidosis and hyperglycemic hyperosmolar status. 3. had used drugs that is known to have effect on bone(like active vitamin D, bisphosphonate, calcitonin, estrogen receptor modulators, estrogen, thiazolidinediones); 4. suffer from diseases that is known to have effect on bone (hyperthyroidism, hypothyroidism, hyperparathyroidism, hypoparathyroidism,cushing syndrome,chronic renal failure,renal tubular acidosis,osteoporosis after gastrectomy,osteoporosis caused by liver disease,rheumatoid disease,osteoporosis induced by gastrointestinal absorption dysfunction); 5. disuse osteoporosis; 6. cannot be exposure to sunlight due to skin diseases; 7. use glucocorticoids for over 3 months.