Serum retinol and pulmonary function in young people with cystic fibrosis

Abstract

An article recently published in this journal by Woestenenk et al. [1] cites a study on young people with cystic fibrosis published by our research group [2]. Our paper excluded those patients with vitamin A deficiency and those suffering from acute pulmonary exacerbation (by clinical criteria and determination of C-reactive protein in serum). All 98 participants received the daily supplement of vitamin A recommended in cystic fibrosis [3]. Data on serum retinol, expressed as the standard deviation for age, were above the normal range in 31 patients, although no case reached toxic levels. After adjusting the data for gender, age, body mass index and pancreatic function, pulmonary function was clearly higher in these patients than in those with serum retinol within the normal range (Odds ratio for FEV1 N 80%: 3.78 vs. 0.26). Woestenenk et al. retrospectively studied a sample of young cystic fibrosis patients that they stratified according to year of age. Their data on serum retinol and respiratory function (obtained in annual routine checks) did not show any association between the two variables.