Disturbances of parathyroid hormone–vitamin D axis in non-cholestatic chronic liver disease: a cross-sectional study

Abstract

Liver has an important role in metabolism of vitamin D. This study aimed to evaluate the patterns of vitamin D-parathyroid hormone (PTH) disturbance and correlate it in patients with non-cholestatic chronic liver disease (CLD). A total of 40 healthy controls and 90 consecutive patients with evidence of non-cholestatic CLD due to hepatitis C (n=28), hepatitis B (n=26), autoimmune hepatitis (n=19), and cryptogenic causes (n=17) were enrolled. Cirrhosis was evident in 51 patients. Serum concentrations of 25-hydroxy vitamin D, PTH, calcium, phosphate, and liver enzymes were measured. Child-Pugh classification was determined in cirrhotic patients. Vitamin D deficiency (<50nmol/l) was found in 46 (51.1%) patients and vitamin D insufficiency (50-80nmol/l) in 15 (16.7%) patients. Secondary hyperparathyroidism (serum PTH>6.8pmol/l) was present in 6 (6.7%) patients. The prevalence of vitamin D deficiency was significantly higher in cirrhotic versus noncirrhotic patients (76.5 vs. 17.9%; P<0.001), whereas there was no significant difference in serum calcium, phosphate, and PTH levels. Child-Pugh class B and C patients had significantly lower vitamin D level compared with class A patients (P<0.001), whereas there was no significant difference in serum calcium, phosphate, and PTH levels. No significant correlation was seen between vitamin D and PTH, calcium or phosphate levels. Lower serum level of vitamin D was associated with coagulopathy, hyperbilirubinemia, hypoalbuminemia, anemia, and thrombocytopenia. Vitamin D inadequacy and the severity of liver dysfunction move in parallel in patients with non-cholestatic CLD. Vitamin D assessment and replacement should be considered in the management of patients with non-cholestatic CLD.