Background/Purpose: There has been much interest in smoking as a modifiable risk factor for increased disease severity in rheumatic diseases. However, the effects of alcohol consumption remain unclear. Alcohol intake has been associated with increased disease susceptibility in psoriatic arthritis but also with reduced disease severity in rheumatoid arthritis. Its role in axial spondyloarthritis (axSpA) has not been studied in detail. The aim of this study was to explore whether alcohol consumption is associated with disease severity in axSpA.

Methods: Alcohol histories were obtained from axSpA patients meeting the ASAS criteria. Participants were categorised as current drinkers or non-drinkers. Quantity of intake was estimated using units per week with heavy consumption defined as >14 u/week. Disease activity (BASDAI, spinal pain, ASDAS) and functional impairment (BASFI) were compared between alcohol drinkers and non-drinkers, using multivariable linear models adjusting for age, gender, TNF inhibition therapy (TNFi), smoking, index of deprivation and self-reported anxiety and depression (A&D). Given their recognised link, interaction terms between alcohol and A&D were included in these models. Association between heavy alcohol consumption and disease severity was explored within drinkers using multivariable models with the above covariates.

Results: We studied 229 axSpA patients: 76% were male with mean age 46.5 (SD±13.8) years. A third were treated with TNFi. The median BASDAI was 5.7 [interquartile range (IQR) 3.3, 7.6] and BASFI 5.7 [IQR 3.3, 7.6]. ASDAS was available for 79% of patients with mean of 2.7 (SD±1.1). Ever-smoking was reported by 47% and A&D by 54%. Alcohol drinking was reported by 64%, with drinkers reporting median intake of 6 u/week [IQR 2 to 20]. Compared with non-drinkers, drinkers had lower BASDAI, ASDAS and BASFI (Table 1). There were no differences in disease severity between heavy and moderate drinkers. Stratified by smoking status, associations between alcohol and disease severity were stronger in never-smokers. There was a significant interaction between alcohol and A&D in smokers: drinkers had lower BASDAI and BASFI in the absence of A&D.

Conclusion: Alcohol consumption appears to be associated with reduced axSpA disease severity in this cross-sectional cohort. These associations were influenced by smoking status and A&D. This novel finding supports the need for further investigation to explore whether lifestyle modification could lead to better disease outcomes in axSpA.