The Significant Role of Alcohol in the Relationship between C-Reactive Protein and Self-Reported Osteoarthritis

Despite the known inflammatory nature of osteoarthritis (OA) and the established role of C-reactive protein (CRP) as an inflammation marker, the influence of alcohol consumption on the CRP–OA relationship remains uncertain, with previous research providing conflicting results. This study aims to examine the potential moderating effect of alcohol on the association between CRP concentrations and self-reported OA. We conducted a cross-sectional study involving 50,259 participants, all data collected from NHANES between 2005–2010 and 2015–2018. A multivariable logistic regression model was used to analyze the relationship between CRP and OA. We found a nonsignificant positive association between CRP concentration and prevalence of self-reported OA after adjusting for covariates in the raw dataset or 5 multiple imputed datasets. In the stratified analysis by alcohol drinking, for every 10 mg/L higher in CRP concentration, the prevalence of self-reported OA was higher by 13 % in nondrinkers (P = 0.007, adjusted for covariates). Conversely, for every 10 mg/L higher in CRP concentration, the prevalence of self-reported OA was lower by 59 % in drinkers (P = 0.005, adjusted for covariates). Furthermore, we discovered that the directions of the association between CRP concentrations (10 mg/L) and prevalence of self-reported OA [odds ratio (OR) < 1 in the drinking subgroup and OR > 1 in the no-drinking subgroup] were stable in both the main and sensitivity analyses. The significant interaction between CRP concentration and alcohol drinking on the prevalence of self-reported OA was shown in most of our analyses (P-interaction < 0.05). Alcohol consumption may be an interaction factor between CRP and self-reported OA. To our knowledge, our findings are the first to highlight the importance of incorporating analysis of alcohol consumption differences into future studies of CRP and self-reported OA.