Abstract Background and Aims Hypoxia has been considered to be a risk factor for osteoporosis. Several studies have reported on the close associations between the anemia and an increased risk of bone loss. However, the relationship between hemoglobin levels and bone mineral density(BMD) has not been established in chronic kidney disease (CKD) patients. Therefore, the aim of this study is to investigate the relationship between BMD and anemia in a non-dialysis CKD cohort. Method Among 2,238 patients with non-dialysis CKD enrolled in the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD), 2,115 patients who measured hemoglobin(Hb) and BMD were included in the analysis. We defined anemia as hemoglobin(Hb) levels of < 13.0 g/dL and 12.0 g/dL for males and females, respectively. The primary endpoint was the onset of a 15% decline in Hemoglobin during follow-up. Results The mean age was 53.6 ± 12.2 years and 1,292(61.1%) patients were males. The BMD score was positively correlated with hemoglobin levels (β, 0.658; 95% CI, 0.215-1.101; P 0.004). In the multivariable logistic regression model, the prevalence of anemia was significantly higher in the osteoporosis group than that in the normal BMD group (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.03-2.46, P=0.038). Among 1010 patients without data of following hemoglobin levels, 396 (19.7%) patients developed 15% decline in hemoglobin level during a median follow-up duration of 36 (interquartile range, 10-60) months. In the fully adjusted multivariable Cox models, risk of developing the 15% decline of hemoglobin was significantly higher in the osteoporosis group (HR, 1.45; 95% CI, 1.03-2.05; P= 0.035) as compared to normal BMD group. Conclusion This study showed that low bone mass density was independently related with anemia and hemoglobin levels in patients with non-dialysis CKD. Our findings suggest that preserve bone mass be important to maintain the levels of hemoglobin with CKD patients.
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