Ethanol Consumption is Associated with Decreased Risk for Developing RA: Results from the Swedish EIRA Study - OP 0129
Authors: Kallberg, Padyukov, Ronnelid, Klareskog, Alfredsson
Background:
Certain environmental exposures, such as cigarette smoking, have been shown to be powerful risk factors for the development of RA. Alcohol intake has shown to be both protective and detrimental in a number of disease states. Here, Kallberg et al explore the effect of alcohol intake on incident RA.
Methods:
Subjects derived from the Swedish Epidemiological Investigation of RA (EIRA) study, a population-based case-control study of incident adult onset RA from Sweden. Incident RA cases were randomly matched to an age, gender, and geographically compatible control subject without RA. Data on lifestyle factors and environmental exposures, including alcohol consumption, were collected at baseline and compared between cases and controls.
Results:
1,419 incident RA cases were compared to 1,674 non-RA controls enrolled between May 1996 and December 2003. Subjects were classified according to alcohol consumption (none, low (0-3 drinks per week), moderate (4 -10 drinks per week), and high (> 10 drinks per week)). Subjects in the low consumption group were the comparison group.
Odds of Incident RA According to EtOH consumption compared to Low EtOH consumption
|
Odds Ratio |
95% CI |
No EtOH Consumption |
1.1 |
0.8 – 1.4 |
Low EtOH (0-3 drinks per wk) |
referent |
-- |
Moderate EtOH (4 – 10 drinks per wk) |
0.6 |
0.4 – 0.7 |
High EtOH (>10 drinks per wk) |
0.5 |
0.4 – 0.6 |
High alcohol consumption reduced, but did not abrogate, the risk of incident RA in patients with risk factors for RA (i.e. anti-CCP antibody seropositivity, smoking, shared epitope).
Conclusions:
Increasing alcohol consumption was associated with protection against the development of RA.
Editorial Comment:
These are novel findings which deserve more investigation into the mechanistic basis of the effect. The authors cite studies suggesting that alcohol may inhibit intracellular signaling pathways that may be responsible for the development of inflammatory arthritis. However, caution should be used when ascribing a direct pathogenic relationship between an exposure and its putative effect. Moderate alcohol intake is highly associated with a number of health behaviors that may confound the association. For example, the population in question, located in southern Sweden, is generally affluent with wine the most prominent alcoholic beverage consumed. Other epidemiologic studies have shown that people who drink 1 to 2 glasses of wine per day tend toward a higher socioeconomic status and engage in other beneficial health behaviors, such as exercise and maintenance of healthy body composition. It would be interesting to see if very heavy alcohol intake (i.e. alcoholism) remains protective, or whether the effect is centered in a population that is essentially moderate in its consumption of alcohol (i.e. 2 glasses of wine per day or 14 drinks per week).
