Helicobacter pylori infection as a risk factor for serum bilirubin change and less favourable lipid profiles: a hospital-based health examination survey

BACKGROUND: Helicobacter pylori infection is associated with several extragastric conditions including dyslipidemia and metabolic syndrome. This study aimed to investigate additional metabolic parameters associated with H. pylori infection in a Chinese population. METHODS: Using a case-control approach we studied 617 subjects with (13)C-urea breath test ((13)C-UBT) values ≥10‰ who were defined as being positive for H. pylori (cases), while 617 sex and age- matched subjects with (13)C-UBT values ≤1‰ were defined as H. pylori negative (controls) in Beijing Tongren Hospital from March 2016 to May 2017. Biochemical parameters including serum bilirubin and lipids were tested. RESULTS: A total of 1982 subjects participated in this study. The H. pylori infected subjects had significantly lower serum direct bilirubin concentrations (2.34 ± 0.38 vs. 2.47 ± 0.90 μmol/L, P = 0.008). H. pylori infection was independently associated with lower direct bilirubin levels (OR = 1.497, 95% CI =1.121–1.999, P = 0.006) or total bilirubin levels (OR = 1.322, 95% CI =1.005–1.738, P = 0.046) after adjustment for age, sex, body mass index (BMI), alanine aminotransferase (ALT), aspartate aminotransferase (AST), high-density lipoprotein cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), total cholesterol (TC) and triglycerides(TG). In addition, the H. pylori infected subjects had higher LDL-C levels (2.98 ± 0.76 vs. 2.89 ± 0.75 mmol/L, P = 0.033) and lower HDL-C levels (1.39 ± 0.37 vs. 1.44 ± 0.41 mmol/L, P = 0.044). LDL-C was negatively correlated with direct bilirubin concentration (R = − 0.260, P < 0.0001). CONCLUSIONS: Bilirubin has been found to be a potent endogenous antioxidant and negatively associated with metabolic syndrome. Our results suggest that H. pylori infection is an independent risk factor for serum bilirubin reduction and less favorable lipid profiles. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12879-019-3787-8) contains supplementary material, which is available to authorized users.