Relationship between Parathyroid Hormone Level and Degree of Hepatic Steatosis by Fibroscan among Prevalent Hemodialysis Patients

Abstract Background Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome (MS) which may be related to cardiovascular mortality among hemodialysis (HD) patients. Hepatic steatosis contributed to many factors related to MS, atherogenic dyslipidemia, insulinresistance, and adipose tissue hormones. Elevated parathyroid hormone is associated with insulin resistance and atherosclerosis and may be considered an independent predictor of metabolic syndrome. some studies reported an association between elevated PTH and non-alcoholic steatohepatitis. However, the relationship between hyperparathyroidism and NAFLD in HD patients is not well defined. Aims of the Study To test the hypothesis of a possible association between hyperparathyroidism and the presence of hepatic steatosis and fibrosis by transient elastography and to evaluate the possible risk factors of NAFLD among hemodialysis patients. Patients and Methods This is a Case-control study included: Group I: (30) chronic HD patients with NAFLD, Group II: (25) chronic HD patients without NAFLD, and Group III: 30 healthy volunteers as a control group. Infection with a hepatotropic virus, Diabetes mellitus (DM), patients with a history of recent hepatobiliary surgery, Abdominal Ascites, Active infection, fever, Active malignancy, drugs induce hepatic steatosis, or Alcohol abuse were excluded. All subjects were subjected to full history and clinical examination. Laboratory tests: Complete blood count (CBC), Iron profile, Serum creatinine, Urea, Calcium (Ca), phosphorus, Intact parathyroid hormone (iPTH), Serum Alkaline phosphatase (ALP), γ-glutamyl transferase (GGT), Serum Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Albumin, Total bilirubin, Total cholesterol, High-density lipoprotein cholesterol (HDL), Low-density Lipoprotein cholesterol (LDL), Triglycerides (TG), C -reactive protein (CRP) Titre, HBsAg, HCV Ab and Urea reduction ratio (URR). Transient elastography Fibroscan® for assessment of Controlled attenuation parameter (CAP) to detect liver steatosis grades and liver stiffness measurement to quantitate liver fibrosis was done. Results The mean ±SD values of CAP of liver steatosis (263.7 ± 52.7, 181.3 ± 23, 210.8 ± 33.7) (dB/m) in group I, II and control group respectively (P < 0.001). There were significant differences between the studied group as regard body mass index (BMI), serum Ca, phosphorus, ALP and GGT and CRP titer, PTH and liver function tests, and lipid profile (P < 0.001). Post Hoc analysis revealed a significant statistical difference between group I and II groups as regard ALT, AST, Bilirubin level and serum albumin, CRP titer, and lipid profile (P < 0.5). In HD patients studied groups, the CAP value of liver steatosis was statistically significantly correlated to BMI ALT (r = 0.387, P=0.004), AST (r = 0.365, P = 0.006), Cholesterol (r = 0.785, P < 0.001), LDL (r = 0.692, P < 0.001), TG (r = 0.668, P <0.001), CRP Titre (r=0.384, P=0.004), but not correlated to PTH or other studied parameters (P > 0.05). In control group III, there was a significant correlation between the measured CAP Value of liver steatosis and BMI, PTH, CRP titer, ALT, AST, cholesterol, LDL, and a negative correlation between HDL and CAP value (P < 0.05). liver stiffness /fibrosis was observed in 18 (60.0%) of HD patients in group I versus 8 (32%) patients in group II (P < 0.05). The mean value of liver stiffness (Kpa) was (6.73 ± 6.08, 6.39 ± 5.65, 4.57 ± 0.75) in groups I, II, and the control group respectively (P < 0.001) and post hoc analysis showed a significant difference between Group I and Group II (P = 0.04) and between group I and control group p (<0.001). There was a significant difference between group I and group II and between group I and the control group regarding mean values of liver stiffness (Kpa) (P < 0.05) Conclusions Non-alcoholic liver disease (NAFLD) in prevalent hemodialysis patients is significantly correlated to high cholesterol, LDL, triglycerides, low HDL, increased body mass index, and CRP titer as a marker of inflammation, but not significantly correlated to elevated parathyroid hormone level. NAFLD is a risk for liver stiffness /fibrosis among chronic hemodialysis patients.