RESUMO
OBJECTIVE: Elderly people show an increased risk of acute respiratory infections and their complications. This increased susceptibility may be the result of immunosenescence. If lifestyle factors could influence the risk of the infections, this could result in great public health relevance. We investigated the relation between alcohol consumption, smoking, and physical activity with acute respiratory infections. DESIGN: Prospective observational analysis. SETTING: The study took place between September 1998 - June 2000, in the Wageningen area of The Netherlands. PARTICIPANTS: In total 652 relatively healthy elderly people participated. Participants were noninstitutionalized and 60 years and older. MEASUREMENTS: The lifestyle factors were assessed at baseline by means of standardized and validated questionnaires in the participants. Self-reported respiratory infections were assessed from 1998-2000 by nurse telephone contact, and home visits, and were evaluated by microbiological tests in a subset. RESULTS: We detected 1024 acute respiratory infections among 443 participants, the overall incidence rate (IR) was 1.6 infections per person per year. IR ratio (95% confidence interval) of the infections was 1.31 (1.01, 1.70) for occasional (superior 0 glasses/day < 1), 1.22 (0.92, 1.64) for light (1 < glasses/day < 3 (men) and 1< glasses/day < 2 (women)), and 1.33 (1.04, 1.83) at moderate/heavy (superior 3 (men) or superior 2 (women) glasses/day) alcohol consumption after adjustment for age and sex. Alcohol intake was not related to illness severity. Smoking and physical activity were not related to the incidence and severity of the infections. All results remained unaltered after adjustment for lifestyle factors and for other potential risk factors for respiratory infections. CONCLUSION: Our findings suggest that only alcohol intake may be unfavorably associated with the frequency of acute respiratory infections in apparently healthy elderly people. Until our results are confirmed in trials, it is not warranted to recommend elderly people to change their habits of life, such as alcohol consumption, smoking and physical activity in order to reduce the risk of acute respiratory infections.