Full Story:  Endocrinology Today

BALTIMORE — Higher concentrations of inflammatory factors were associated with higher risk for hip fracture, according to study results presented here.

“Inflammatory burden may be an important biological factor in fracture etiology, particularly for hip fractures, and now we are seeing this consistency across studies,” Kamil E. Barbour, PhD, MPH, MS, of the CDC, said. “Our association between the inflammatory markers and hip fracture was due in large part to poor renal function, so what is the possible biological mechanism for this? We know that the basic science literature shows glomerular injury may occur directly by cytokines or indirectly through mediation of immune cells. But we must acknowledge the mediation could be in the other direction where poor kidney function results in higher inflammation and subsequently results in higher fracture risk.”

Researchers using data from the year 10 of Study of Osteoporotic Fractures analyzed the assays of 1,339 women (mean age, 80 years) and followed them for a median follow-up time of 6.3 years.

Researchers separated inflammatory marker levels into quartiles, showing that the HR of hip fracture and 95% CI for women in the highest quartile of inflammatory markers, as compared with those lowest quartile, was 1.7 (95% CI, 1.1-2.5) for interleukin-6, 1.5 (95% CI, 1.0-2.1) for IL-6 soluble receptor (SR), 2.0 (95% CI, 1.4-3.1) for tumor necrosis factor (TNF) SR1 and 1.2 (95% CI, 0.8-1.8) for TNF SR2.

Researchers separated inflammatory marker levels into quartiles, showing that the HR and 95% CI of hip fracture for women in the highest quartile of inflammatory markers, as compared with those in the lowestquartile, was 1.7 (95% CI, 1.1-2.5) for interleukin-6, 1.5 (95% CI, 1.0-2.1) for IL-6 soluble receptor (SR), 2.0 (95% CI, 1.4-3.1) for tumor necrosis factor (TNF) SR1 and 1.2 (95% CI, 0.8-1.8) for TNF SR2.

Women with two of the four inflammatory markers in the top quartile had an HR of hip fracture of 1.5 (95% CI, 1.1-2.1); women with three or more inflammatory markers in the top quartile had a hip fracture HR of 1.4 (95% CI, 0.9-2.3), in comparison with those women with zero or one marker (P trend=.03).

After adjusting for six potential mediators, cystatin C was most associated with the most attenuation of the dose-response relationship (P trend=.24), more so than bone mineral density (P trend=.16).

Based on this and other studies, Barbour said older women with high inflammatory markers have a higher risk for hip fracture due in part to high cytokine levels associated with loss of BMD. – by Katrina Altersitz

For more information:

Barbour KE. Oral Presentation #1083. Presented at: the American Society of Bone and Mineral Research 2013 Annual Meeting; Oct. 4-7, 2013; Baltimore.

Disclosure: Barbour reports no financial disclosures.