July 30, 2010 — Alcohol consumption appears to have an inverse and dose-related association with both risk for and severity of rheumatoid arthritis (RA), according to the results of a study reported online July 28 in Rheumatology. However, the investigators note various limitations of the study.
"We found that patients who had drunk alcohol most frequently had symptoms that were less severe than those who had never drunk alcohol or only drunk it infrequently," said lead author James Maxwell, a consultant rheumatologist at the Rotherham Foundation NHS Trust and an honorary senior clinical lecturer in the Academic Rheumatology Group at the University of Sheffield, Sheffield, United Kingdom, in a news release. "X-rays showed there was less damage to joints, blood tests showed lower levels of inflammation, and there was less joint pain, swelling and disability. This is the first time that a dose-dependent inverse association between frequency of alcohol consumption and severity of RA has been shown in humans."
The goal of the study was to examine the relationship between frequency of alcohol drinking and RA risk and severity. Patients with erosive RA (n = 873) and healthy control subjects (n = 1004) completed a self-reported questionnaire regarding frequency of alcohol consumption. After adjustment for age, sex, and smoking status, odds ratios (ORs) for RA risk were calculated on the basis of alcohol intake. The investigators calculated median values of all RA severity measures according to frequency of alcohol drinking and used the nonparametric trend test to evaluate association. To adjust for potential confounding, they used a negative binomial regression model.
Increased frequency of alcohol drinking was associated with a decreased risk for RA. Compared with participants reporting alcohol consumption on 10 or more days per month, nondrinkers had an OR for RA of 4.17 (95% confidence interval [CI], 3.01 - 5.77; P for trend < .0001).
"This finding agrees with the results from previous studies that have shown a decreased susceptibility to developing RA among alcohol drinkers," Dr. Maxwell said.
Increased frequency of alcohol drinking was inversely associated with all measures of RA severity including C-reactive protein, 28-joint disease activity score, pain visual analog scale, the modified Health Assessment Questionnaire, and modified Larsen score (P for trend, each < .0001). Frequency of alcohol drinking was still significantly and inversely associated with x-ray damage and the modified Health Assessment Questionnaire, even after adjustment for potential confounding in a multivariate regression model.
"There is some evidence to show that alcohol suppresses the activity of the immune system, and that this may influence the pathways by which RA develops," Dr. Maxwell said. "We do know that the changes in the immune system that lead to RA happen months and maybe even years before the arthritis actually develops. Once someone has developed RA, it's possible that the anti-inflammatory and analgesic effects of alcohol may play a role in reducing the severity of symptoms."
The study findings were independent of sex and the presence or absence of both the anticyclic citrullinated peptide (CCP)–positive and negative forms of RA.
"Anti-CCP antibodies are not present in most 'normal' people without arthritis," Dr. Maxwell said. "We know that these antibodies develop prior to the onset of RA, and are probably directly linked to the process which causes RA. Some patients have RA without having anti-CCP antibodies, but we know that the disease is much more severe in patients who do."
Limitations of the study include retrospective cross-sectional design, possible recall bias, and marked differences in age and sex between the RA group and the control group. In addition, frequency rather than quantity of alcohol consumption was recorded, and the predominantly Caucasian population precludes generalization to other ethnic groups.
"Further research is needed to confirm the results of our study and to investigate the mechanisms by which alcohol influences people's susceptibility to RA and the severity of symptoms," Dr. Maxwell concluded. "It is also possible that different types of alcoholic drinks may have different effects on RA."
The Arthritis Research Campaign supported this study. The study authors have disclosed no relevant financial relationships.
Rheumatology. Published online July 28, 2010.
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Cite this: Alcohol Consumption Inversely Associated with Risk for and Severity of Rheumatoid Arthritis - Medscape - Jul 30, 2010.