Association of lower serum cholesterol levels with higher risk of osteoporosis in type 2 diabetes.

OBJECTIVE

To determine whether a correlation exists between bone mineral density and circulating lipoprotein levels and whether these variables are independently associated with osteoporosis in patients with type 2 diabetes.

METHODS

In a cross-sectional analysis, 159 patients with type 2 diabetes were compared with 70 patients without diabetes selected from an outpatient endocrinology clinic in a tertiary care institute during a 1-year period. Variables were gathered through history, physical examination, and laboratory findings, including blood chemistry studies and dual-energy x-ray absorptiometry.

RESULTS

Of the 229 study patients, 86 (37.6%) had osteoporosis. In the patients with diabetes, the mean +/- SD of age, weight, total cholesterol, and low-density lipoprotein (LDL) cholesterol in those with and without osteoporosis was 72.3 +/- 10.4 years versus 63.6 +/- 11.0 years, 74.2 +/- 14.4 kg versus 83.7 +/- 15.5 kg, 178.4 +/- 33.7 mg/dL versus 194.1 +/- 33.9 mg/dL, and 100.0 +/- 27.1 mg/dL versus 114.2 +/- 30.2 mg/dL, respectively (P<0.01 for all variables). After adjustment for other variables, multiple logistic regression analysis showed that the presence of diabetes was associated with a lower risk of osteoporosis. Similarly, older age and lower body weight, LDL levels, and serum calcium levels were independently associated with lumbar spine osteoporosis in patients with diabetes, in comparison with older age and lower weight in patients without diabetes. Lower weight and older age were associated with femoral neck and total hip osteoporosis in patients with diabetes, in comparison with only older age in patients without diabetes.

CONCLUSION

The presence of type 2 diabetes is associated with a lower risk of osteoporosis. In patients with type 2 diabetes, a lower LDL level is more likely to be associated with osteoporosis at the lumbar spine.