Prevalence of abnormal serum 25-hydroxyvitamin D and its association with hemoglobin level in pre dialysis CKD patients: a cross-sectional study from Himalayan country

BACKGROUND: CKD has been recognized as risk factors for 25(OH) D deficiency, and Low levels of 25(OH) D have been suggested to be a trigger factor of decreased level of Hb. However, there is lack of information about the magnitude of 25(OH) D deficiency and Hb level in Nepalese CKD patients. Therefore, the aim of present study was to investigate the prevalence of abnormal 25(OH) D in non-dialyzed CKD patients, and further to examine its association with Hb level. METHODS: In this cross-sectional study, we examined 172 clinically stable patients with an eGFR at CKD stage2–5 not on dialysis. Serum 25(OH) D, Hb, levels were evaluated as a core variables and the other variables such as age, sex, co-morbidities (HTN, DM), eGFR, Hb, iPTH, serum phosphate, albumin, calcium, and phosphate level were evaluated as a covariates. Serum 25(OH) D, Hb levels and the factors associated with 25(OH) D level were evaluated. RESULTS: The estimated prevalence of abnormal 25(OH) D metabolite (< 30 ng/mL) in this predialysis patients were (87.8%), with 32 and 55.8% deficiency and insufficiency 25(OH) D metabolite, respectively. On regression analysis, serum 25(OH) D was positively associated with male subjects (P = 0.02), serum albumin(P = 0.002), and eGFR (P = 0.042), while inversely associated with age (P = 0.006), iPTH(P = 0.025). Hb concentration was found to be positively correlated with 25(OH) D (P < 0.05) in both univariate as well as in multivariate analysis. CONCLUSION: A high prevalence of abnormal 25(OH) D metabolite was observed in early CKD patients. Our study shows that lower level of 25(OH) D level are associated with lower level of Hb and higher level of iPTH, and could play a role in the development of anemia and hyperparathyroidism.