C-reactive protein, bone loss, fracture, and mortality in elderly women: a longitudinal study in the OPRA cohort

Summary This longitudinal study investigates the association between C-reactive protein (CRP), osteoporosis, fractures, and mortality in 1044 elderly women. CRP was not an indi- cator for low bone mineral density (BMD), bone loss, or fracture in elderly women; however, women with elevated CRP levels over a prolonged period lost more bone over the 10-year follow-up, although fracture risk was not increased. Introduction Inflammation may contribute to the pathophys- iology underlying impaired bone metabolism. This study in- vestigates the association between CRP, BMD, bone loss, fracture risk, and mortality in women aged 75 and above. Methods This longitudinal study is based on 1044 women, all age 75 at inclusion, reassessed at ages 80 and 85, with a mean follow-up time of 11.6 years (maximum 16.9 years). Results Women in the lowest CRP quartile (mean 0.63 mg/L) had lower BMD compared to those in the highest CRP quar- tile(mean5.74mg/L) attotalhip(TH)(0.809vs.0.871g/cm 2 , p<0.001) and femoral neck (FN) (0.737 vs. 0.778 g/cm 2 , p= 0.007). A singlemeasurement ofCRPwas not associatedwith bone loss; however, women with persistently elevated CRP, i.e., ≥3 mg/L at ages 75 and 80 had significantly higher bone loss compared to women with CRP <3 mg/L (TH −0.125 vs. −0.085 g/cm 2 , p=0.018 and FN −0.127 vs. −0.078 g/cm 2 , p= 0.005) during 10 years of follow-up. Women in the highest CRPquartilehadalower riskofosteoporoticfractures(hazard ratios (HR) 0.76 (95 % confidence intervals (CI) 0.52-0.98)) compared to those in the lowest, even after adjusting for weight and BMD. Mortality risk was only increased among women with the highest CRP levels. Conclusion CRP was not an indicator for low BMD, bone loss, or fracture in elderly women in this study. Persistently elevated CRP however seemed to be detrimental to bone health and may be associated with a higher rate of bone loss. Only the highest CRP levels were associated with mortality.