Fracture burden and risk factors in childhood CKD: Results from the CKiD cohort study

Childhood chronic kidney disease (CHD) poses multiple threats to bone accrual; however, the associated fracture risk is not well characterized. This prospective cohort study included 537 CKD in Children (CKiD) participants. Fracture histories were obtained at baseline, at years 1, 3, and 5 through November 1, 2009, and annually thereafter.We used Cox regression analysis of first incident fracture to evaluate potential correlates of fracture risk. At enrollment, median age was 11 years, and 16% of patients reported a prior fracture. Over a median of 3.9 years, 43 males and 24 females sustained incident fractures, corresponDing to 395 (95% confidence interval [95% CI], 293-533) and 323 (95% CI, 216-481) fractures per 10,000 person-years, respectively. These rates were 2-to 3-fold higher than publishedgeneral population rates.The onlygender difference in fracture risk was a 2.6-fold higher risk in males aged 15 years (570/10,000 person-years, adjusted P=0.04). In multivariable analysis, advanced pubertal stage, greater height Z-score, difficulty walking, and higher average log-transformed parathyroid hormone level were independently associated with greater fracture risk (all P#0.04). Phosphate binder treatment (predominantly calcium-based) was associated with lower fracture risk (hazard ratio, 0.37; 95% CI, 0.15-0.91; P=0.03). Participation in more than one team sport was associated with higher risk (hazardratio, 4.87;95%CI, 2.21-10.75;P,0.001). In conclusion, children withCKDhave a high burden of fracture. RegarDing modifiable factors, higher averageparathyroidhormone level was associated with greater risk of fracture, whereas phosphate binder use was protective in this cohort.