Association between Gastroesophageal Reflux Disease and Elastographic Parameters of Liver Steatosis and Fibrosis: Controlled Attenuation Parameter and Liver Stiffness Measurements

Gastroesophageal reflux disease and non-alcoholic fatty liver disease: a two-sample Mendelian randomization combined with meta-analysis

Accumulating evidence from observational studies have suggested an association between gastroesophageal reflux disease (GERD) and non-alcoholic fatty liver disease (NAFLD). However, due to that such studies are prone to biases, we imported Mendelian randomization (MR) to explore whether the causal association between two diseases exsit. Hence, we aimed to analysis the potential association with MR. The single nucleotide polymorphisms (SNPs) of GERD were retrieved from the genome-wide association study dataset as the exposure. The SNPs of NAFLD were taken from the FinnGen dataset as the outcome. The relationship was analyzed with the assistance of inverse variance weighted, MR-Egger, and weighted median. We also uitilized the MR-Egger intercept, Cochran's Q test, leave-one-out analysis, MR-PRESSO, and Steiger directionality test to evaluate the robustness of the causal association. The meta-analysis were also implemented to give an overall evaluation. Finally, our analysis showed a causal relationship between GERD and NAFLD with aid of MR and meta-analysis (OR 1.71 95% CI 1.40-2.09; P < 0.0001).

The association between Helicobacter pylori with nonalcoholic fatty liver disease assessed by controlled attenuation parameter and other metabolic factors

Aim

Existing studies have suggested an association between Helicobacter pylori (Hp) infection and nonalcoholic fatty liver disease (NAFLD). We investigated the relationship between Hp infection and NAFLD using controlled attenuation parameter (CAP) and other metabolic factors.

Method

We conducted a retrospective cohort study of apparently healthy individuals who underwent liver Fibroscan during health screening tests between January 2018 and December 2018. Diagnosis of Hp infection was based on a serum anti-Hp IgG antibody test and CAP values were used to diagnose NAFLD.

Results

Among the 1,784 subjects (mean age 55.3 years, 83.1% male), 708 (39.7%) subjects showed positive results of Hp serology. In the multivariate analysis, obesity (body mass index ≥25) (odds ratio [OR] 3.44, 95% confidence interval [CI] 2.75–4.29), triglyceride (OR 2.31, 95% CI 1.80–2.97), and the highest tertile of liver stiffness measurement (OR 2.08, 95% CI 1.59–2.71) were found to be associated with NAFLD, defined by CAP ≥248 dB/m, while Hp-seropositivity showed no association with NAFLD. Serum levels of HDL cholesterol significantly decreased in subjects with Hp-seropositivity compared to HP-seronegativity in both groups with and without NAFLD (P<0.001).

Conclusion

While Hp seropositivity was not associated with CAP-defined NAFLD, serum HDL cholesterol level were negatively associated with Hp-seropositivity in both groups with and without NAFLD. Further clinical and experimental studies are necessary to determine the association between Hp infection and NAFLD.

The Association between Vitamin D and Nonalcoholic Fatty Liver Disease Assessed by Controlled Attenuation Parameter

BACKGROUND

An association between nonalcoholic fatty liver disease (NAFLD) and low vitamin D levels has been suggested. We investigated the relationship between vitamin D and NAFLD assessed by controlled attenuation parameter (CAP).

METHODS

We conducted a retrospective cohort study of apparently healthy subjects who underwent Fibroscan during health screening tests. NAFLD was diagnosed using CAP values.

RESULTS

Among the 1202 subjects (mean age 57.2 years, 60.6% male), 630 (52.4%) subjects had NAFLD with CAP ≥ 248 dB/m. Multivariable analysis was conducted after adjusting for metabolic risk factors including diabetes, hypertension, hypercholesterolemia, body mass index, high-density lipoprotein cholesterol, triglyceride and smoking. Higher vitamin D levels showed a lower risk of NAFLD compared to the lowest quartile of vitamin D in a dose-dependent manner (OR 0.68, 95% CI 0.47-1.00 in Q2 vs. Q1; OR 0.65, 95% CI 0.44-0.94 in Q3 vs. Q1; and OR 0.64, 95% CI 0.44-0.94 in Q4 vs. Q1). The highest quartile of vitamin D showed a decreased risk of a severe grade of steatosis (CAP ≥ 302 dB/m) compared to the lowest quartile (OR 0.52, 95% CI 0.31-0.87 in Q4 vs. Q1).

CONCLUSIONS

Higher levels of serum vitamin D were associated with a decreased risk of CAP-defined NAFLD, compared to low levels of serum vitamin D. The association between NAFLD and vitamin D suggests that vitamin D may exert a protective role against NAFLD.