Sex-specific differences in the association between birth weight and lung volume in Japanese young adults.

ABSTRACT

BACKGROUND: Fetal growth disturbances may influence adult lung function and can lead to pulmonary diseases in adulthood. Although the results of previous studies are controversial, low birth weight seems to be associated with poor adult lung function. This study aimed to assess previously unknown information about the sex-specific association between birth weight and adult lung volume in the Japanese population. METHODS: We evaluated pulmonary parameters in 200 consenting young medical students (age, 20-29 years) with a never smoking history at Kochi University. Subjects whose lung function was not sufficiently examined or those with evidence of current or previous respiratory diseases were excluded (n=7). All students underwent spirometry, and their weight records at birth or 3 years of age were obtained from their maternal and child handbooks. Associations between the spirometric parameters and birth/3-year weights were statistically analyzed. RESULTS: We evaluated 91 male and 102 female students. Their mean age was 23.3 years. Assessment revealed that birth weight significantly correlated with the percent predicted value of forced vital capacity (%FVC; rs=0.17, p=0.018) but not with the forced expiratory volume in 1 s/FVC ratio. Sex-specific analysis revealed significant correlations between birth weight and %FVC in males (rs=0.22, p=0.041) but not in females. Body weight at the age of 3 years also significantly correlated with %FVC only in males (rs=0.32, p=0.021). CONCLUSIONS: Birth weight is significantly associated with pulmonary function in Japanese young adults. The associations are especially significant in males.