Ambient nitrogen oxides exposure associated with hepatic steatosis in patients with chronic hepatitis B.

BACKGROUND

To investigate the association between air pollution and hepatic steatosis in patients with chronic hepatitis B.

METHODS

This cross-sectional study enrolled 1068 patients with chronic hepatitis B treated with nucleotide/nucleoside analogs from 2020 to 2023 in Kaohsiung and analyzed the incidence and risk factors for hepatic steatosis. Daily air pollutant concentrations were estimated for the year prior to enrolment.

RESULTS

Patients with hepatic steatosis were reported in 340 (31.8%). Patients with hepatic steatosis had higher concentrations of nitrogen oxides (NOx) compared to those without steatosis (27.8 ppb vs. 25.5 ppb; P = 0.001). Logistic regression analysis revealed that non-liver-cirrhosis was the strongest factor associated with hepatic steatosis (odds ratio (OR)/confidence interval (CI): 4.63/2.85-7.52; P < 0.001), followed by hypertriglyceridemia (OR/CI: 2.09/1.29-3.39; P < 0.001),HBeAg seropositivity (OR/CI: 1.54/1.05-2.26; P = 0.04), BMI (OR/CI: 1.10/1.06-1.14; P < 0.001) and concentrations of NOx (OR/CI: 1.018/1.004-1.033; P = 0.01). Among patients without cirrhosis, logistic regression analysis revealed that the strongest factors associated with hepatic steatosis were hypertriglyceridemia (OR/CI: 1.98/1.17-3.35; P = 0.01), followed by HBeAg seropositivity (OR/CI: 1.51/1.05-2.17; P = 0.03), BMI (OR/CI: 1.10/1.05-1.14; P < 0.001) and concentrations of NOx (OR/CI: 1.02/1.01-1.04; P = 0.01). Patients in the highest quartile of annual NOx-concentration exposure had a two-fold increased risk of hepatic steatosis compared with those in the lowest quartile (OR/CI: 2.20/1.37-3.50). Among patients with cirrhosis, logistic regression analysis revealed that the strongest factors associated with hepatic steatosis were hypertriglyceridemia (OR/CI: 3.79/1.22-11.79; P = 0.02), followed by age (OR/CI: 0.95/0.92-0.99; P = 0.02).

CONCLUSIONS

Higher concentrations of NOx were associated with hepatic steatosis in patients with non-cirrhotic chronic hepatitis B.