Alcohol consumption plus high-salt diet and alcohol consumption plus family history of gastric cancer: synergistic risk factors and precision screening strategies for Helicobacter pylori infection among adults in Huaihe River Basin

Current Helicobacter pylori (HP) prevention and control strategies are mostly based on single-factor assessments, and whether alcohol consumption, high-salt diet, and family history of gastric cancer exhibit joint effects on HP infection remains unclear. This study aims to determine the current prevalence of HP infection among adults in the Huaihe River Basin, and to analyze whether pairwise additive interactions exist among these three risk factors in increasing infection risk, thereby providing a scientific basis for formulating precision stratified prevention and control strategies in high-incidence areas of gastric cancer.

A cross-sectional study design was adopted. Local permanent adult residents were recruited from 27 districts/counties across 4 provinces (Jiangsu, Anhui, Shandong, and Henan) via a multi-stage stratified cluster random sampling. Demographic characteristics, lifestyle factors, and family history of gastric cancer were collected through questionnaire surveys. HP status was determined using the ¹³C-urea breath test. Height and body weight were measured to calculate body mass index (BMI). Based on the results of HP test, the participants were divided into positive and negative groups. Binary logistic regression models, with progressive adjustment for demographic, socioeconomic, and lifestyle confounders, were employed to evaluate the independent associations of each factor. Multiplicative interaction terms and additive interaction measures [relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (S) ] were calculated to quantify the synergistic effects among these factors.

A total of 7629 participants were included in the study, with an overall HP positivity rate of 29.6% (n=2255). Multivariate logistic regression analysis revealed that preference for high-salt diet (OR=1.36, 95%CI: 1.19 to 1.56, P<0.001) and family history of gastric cancer (OR=1.56, 95%CI: 1.22 to 1.99, P<0.001) were significantly positively associated with HP infection; alcohol consumption was negatively associated with HP infection (OR=0.77, 95%CI: 0.67 to 0.88, P<0.001). Interaction analysis revealed a synergistic effect when alcohol consumption was combined with other risk factors. The combination of alcohol consumption and high-salt diet showed significant positive multiplicative (OR=1.03, 95%CI: 1.01 to 1.04) and additive (AP=0.166, 95%CI: 0.023 to 0.308) interactions, with a coexisting OR of 2.012 (95%CI: 1.680 to 2.630, P<0.001), although the additive interaction indicators RERI and S did not reach statistical significance. Alcohol consumption and family history of gastric cancer showed a positive interaction (AP=0.194, 95%CI: 0.050 to 0.337), with the coexisting OR increasing to 2.521 (95%CI: 1.615 to 3.934, P<0.001), but multiplicative interaction and additive indicators RERI and S did not reach significance. The co-exposure of high-salt diet and family history of gastric cancer also yielded a positive additive trend (AP=0.207, 95%CI: 0.063 to 0.350).

The prevalence of HP infection among adults in the Huaihe River Basin remains relatively high. High-salt diet and family history of gastric cancer are risk factors for HP infection (Alcohol consumption shows a negative association but should not be used for prevention), and lifestyle and genetic background exhibit potential synergistic effects on the infection with public health significance.

Based on the “Healthy China Initiative—Cancer Prevention and Control Action Plan (2023—2030)”, it is recommended to establish a combined exposure screening mechanism integrating “lifestyle plus family history” in gastric cancer high-risk areas, prioritizing “alcohol consumption combined with high-salt diet” and “drinkers with a family history of gastric cancer” as high-risk screening populations. Family-based “simultaneous screening and treatment” should be promoted, integrating salt-reduction environmental modification with eradication therapy for high-risk members. Joint health education on “alcohol limitation and salt reduction” should be strengthened to correct the misconception that “alcohol consumption prevents HP”, hereby promoting organic integration of primary and secondary prevention.