Bone Mineral Density Declines Early in Men With Type 1 Diabetes, Study Finds

Bone mineral density (BMD) declines early in the course of type 1 diabetes (T1D) in men but is little affected by the condition in women, according to a 10-year prospective study.

It is already known that T1D is associated with a 6-fold increase of hip fracture, although why this is true is not completely understood. Underlying factors include those specific to bone, both reduced BMD and impaired bone quality, as well as an increased fall risk from sensory and autonomic neuropathy, visual impairment and hypoglycemia.

Most studies have shown a reduction in BMD with T1D, with some reporting a greater decrease in men than in women.

An earlier study found that adult men but not women with T1D had reduced BMD at the hip, femoral neck and spine, compared with matched controls. For this study, the same cohort was analyzed, and researchers were able to reassess 48 of the 102 study participants with diabetes after a mean of 10 years. Of the 48, 20 were males and 28 were females. The mean age was 42 years and the median diabetes duration was 14.6 years at baseline.

After adjustment for age and body mass index, men showed a statistically significant increase in BMD and T-score at the lumbar spine over 10 years (P = 0.009). There was a similar but nonsignificant trend at the forearm. There was no change at the hip or femoral neck.

Women showed no change in BMD or T-score at any site after adjustment for age, BMI and postmenopausal status.

Men in the current study had lower mean BMD than both controls (derived from the National Health and Nutrition Examination Survey III (1988-94) and female counterparts in the present study.

Over the 10 years, men had significant declines in biochemical and hormonal markers of bone metabolism serum total procollagen type 1 N propeptide and osteocalcin and a nonsignificant trend to reduction in beta carboxy-terminal type I collagen telopeptide. There were no other significant changes in biochemical or hormonal markers of bone metabolism in males or females.

BMD, estimated by bone densitometry, or DEXA, is a valuable tool in assessing the likelihood of fracture in older individuals, the study noted. But the researchers said their data and those of others suggest that BMD is likely to have a limited role in the context of younger individuals with type 1 diabetes.

There is a need for studies of bone mineralization early in the course of T1D in males, they suggested, since this seems to be when the reduction in BMD, perhaps as a result of the sex-specific effects of a period of insulin deficiency and poor metabolic control.

Reference

Hamilton EJ, Drinkwater JJ, Chubb SAP, et al. A ten-year prospective study of bone mineral density and bone turnover inmales and females with type 1 diabetes. [published July 18, 2018]. J Clin Endocrinol Metab. doi: 10.1210/jc.2018-00850.