Diabetes increased risk for major osteoporotic, hip fracture

Diabetes is a stand-alone risk factor for major osteoporotic fractures but does not alter the effect of Fracture Risk Assessment Tool risk factors or prior fracture site, according to a presentation at the American Society for Bone and Mineral Research 2014 Annual Meeting.

The chronic disease was found to exert a stronger effect in younger individuals than older in terms of hip fracture risk, which warrants consideration when predicting hip fractures, according to Canadian researchers.

“Older patients with diabetes have 32% higher major osteoporotic fracture risk than expected, given their higher bone mineral density and BMI,” William Leslie, MD, of the University of Manitoba, told Endocrine Today.

William Leslie

“Despite this, major osteoporotic fracture prediction in diabetes can use conventional risk factors since there was no significant effect modification by diabetes: Lower BMD increases risk for fracture to the same extent in those with and without diabetes; higher BMI is protective for fracture; prior fracture predicts future fractures,” Leslie said.

Based on a clinical DXA results registry for Manitoba, Leslie and colleagues identified women and men aged at least 40 years undergoing baseline DXA between 1996 and 2011. The researchers used health services data to identify diabetes diagnosis, Fracture Risk Assessment Tool (FRAX) risk factors and incident fractures through previously validated algorithms.

Prior fracture was stratified into categories of clinical vertebral, hip, humerus, forearm, pelvis and other. The researchers tested for statistical interactions of diabetes with FRAX clinical risk factors and prior fracture site using Cox proportional hazards models.

At follow-up, on average 6 years, there were 4,218 major osteoporotic fractures and 1,108 hip fractures. Diabetes was an independent risk factor for major osteoporotic fractures, with adjustments for FRAX risk factors including BMD (HR=1.32; 95% CI, 1.20-1.46). No significant interactions of FRAX risk factors or prior fracture site with diabetes were observed through major osteoporotic fractures analyses.

For hip fracture prediction, age significantly modified the effect of diabetes:

Younger than 60 years, HR=4.67 (95% CI, 2.76-7.89);
Aged 60 to 69 years, HR=2.68 (95% CI, 1.77-4.04);
Aged 70 to 79 years, HR=1.57 (95% CI, 1.2-2.04);
Aged at least 80 years, HR=1.42 (95% CI, 1.1-1.99).

“A simple adjustment to the WHO FRAX major osteoporotic fracture probability output can accommodate the effect of type 2 diabetes,” Leslie said. “For hip fracture prediction, an age-specific adjustment is needed.” — by Allegra Tiver

For more information:

Leslie WD. Abstract #1101. Presented at: American Society for Bone and Mineral Research 2014 Annual Meeting; Sept. 12-15, 2014; Houston.

Leslie WD. Osteoporos Int. 2014;doi:10.1007/s00198-014-2822-2.

Disclosure: Leslie reports no relevant financial disclosures.