Relationship between alcohol consumption and rheumatoid factor (RF) with alcohol-induced facial flushing response

This study investigated the relationship between alcohol consumption with alcohol-induced facial flushing response and rheumatoid factor (RF) in adult men. The cohort comprised 1675 men who underwent a general medical check-up between July 2016 and June 2017, including 355 non-drinkers, 498 flushers, and 822 non-flushers. One drink was defined as 14 g of alcohol. RF was considered negative if the level was less than 18 IU/mL and positive if the level was greater than 18 IU/mL. Logistic regression analyses were used. Compared to non-drinkers, the odds ratio for a positive RF among non-flushers was 0.92 (95% confidence interval [CI], 0.37–2.29) for those with an average alcohol consumption of ≤4 drinks per week, 1.64 (95% CI, 0.67–3.98) for those consuming more than 4 drinks per week but fewer than or equal to 8 drinks per week, and 1.17 (95% CI, 0.55–2.50) for those consuming more than 8 drinks per week; the differences were not statistically significant. Compared to non-drinkers, flushers also had a non-significant odds ratio for positive RF of 1.26 (95% CI, 0.54–2.90) among those with an average alcohol consumption of ≤4 drinks per week. However, flushers showed a significantly higher odds ratio for a positive RF of 3.12 (95% CI, 1.18–8.24) among those consuming more than 4 but fewer than or equal to 8 drinks per week, and 3.27 (95% CI, 1.42–7.52) among those consuming more than 8 drinks per week. Additionally, flushers consuming more than 8 drinks per week were associated with significantly higher rates of positive RF than non-flushers (odds ratio, 2.38; 95% CI, 1.05–5.17). Our study revealed that flushers consuming more than 4 drinks per week showed a higher probability of positive RF than non-drinkers. Furthermore, flushers consuming more than 8 drinks per week had a higher probability of positive RF than non-flushers. Our results strongly indicate that the average weekly alcohol consumption level and the presence or absence of flushing should be considered when interpreting the results of RF examinations in healthy men.