Adult height and cryptogenic fibrosing alveolitis: A case-control study using the UK General Practice Research Database

Background - The reasons why cryptogenic fibrosing alveolitis has emerged as a new clinical entity during the second half of the 20th century are unclear. Some environmental exposures have been identified as potential risk factors including occupational dust, cigarette smoking and antidepressants, but there have been no studies of the role of early life exposures. Since adult height reflects, in part, early life experience, we have examined the relation between adult height and the risk of cryptogenic fibrosing alveolitis. Methods - A case-control study of 569 cases and 3669 age, sex, and community matched controls drawn from the UK General Practice Research Database was undertaken. Results - Evidence was found of an inverse association between quintile of height and cryptogenic fibrosing alveolitis (odds ratio (OR) per increase in height quintile 0.93, 95% CI 0.86 to 0.99). This association was not diminished by adjustment for smoking status (OR 0.93, 95% CI 0.87 to 1.00), but some minor attenuation did occur after adjustment for oral corticosteroid use (OR 0.94, 95% CI 0.88 to 1.02). There was a significant interaction with sex such that the effect of height was strong in women (OR 0.85, 95% CI 0.75 to 0.97) and absent in men (OR 1.00, 95% CI 0.91 to 1.09). Conclusions - These findings raise the possibility that early life exposures may be important in determining the lifetime risk of developing cryptogenic fibrosing alveolitis.