Evaluating the role of vitamin D metabolites and intact parathyroid hormone across chronic kidney disease stages

Evaluating Vitamin D Metabolites and iPTH in CKD Stages

Abstract

Background: Chronic kidney disease (CKD) is defined by abnormalities in kidney structure or function lasting over three months. Its prevalence rises with age particularly affecting 38% of individuals aged 65 and older. Key biomarkers for assessing CKD severity include low estimated glomerular filtration rate (eGFR) and increased albumin levels in urine, determined by the albumin-to-creatinine ratio (ACR). 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D are impaired in CKD patients due to reduced renal function, leading to deficiencies in active vitamin D forms and contributing to secondary hyperparathyroidism (SHPT). Evaluating the Role of vitamin D metabolites and intact Para Thyroid Hormone in different stages of CKD.

Subjects & Methods: This cross-sectional study was performed at Al-Imam Al-Sadiq Hospital in Babil, Iraq. The study included 164 patients (84 males and 80 females) with CKD stages 2-5. Patients were divided into groups based on CKD stages: 20 patients with stage 2, and 36 with each stages 3a, 3b, 4, and 5. Blood samples were collected for serum analysis of urea, creatinine, 25 OH D, 1,25 (OH)2 D, and intact PTH levels. Urine samples were collected for microalbuminuria assessment. ELISA techniques were used for vitamin D and PTH measurements, while standard biochemical methods were employed for other parameters.

Results: 1,25 (OH)2 D and 25 OH D indicated a significant decline with advancing CKD stages (p ≤ 0.001), while iPTH levels increased significantly (p ≤ 0.001). The 1,25VitD/iPTH ratio decreased significantly across CKD stages (p ≤ 0.001).

Conclusion: The study concluded an important association between deteriorating CKD (destruction of renal), declining vitamin D metabolites (25 OH D, 1,25 OH D), and elevated iPTH levels.