Can a Child’s Current BMI Affect Their Future Lung Function? Study Sheds Light - Video

An abnormal BMI in children -- be it high or low -- can now be associated with impaired lung function, but if their BMI is normalised before they reach adulthood, the impairment can be offset, researchers from Karolinska Institutet report. Their results, which are based on data collected under the BAMSE project in Sweden, are presented in The European Respiratory Journal.

One risk factor associated with impaired lung function development is abnormal weight and height. The most common body measurement, BMI (body mass index), takes account of weight, but not muscle and fat composition.

The participants could be divided up into different BMI groups, which had already begun to differentiate themselves by the age of two. Unlike children with a normal BMI, those with a persistently high BMI or an accelerated increasing BMI had impaired lung function as adults, primarily the result of restricted airflow in the lungs, a condition known as obstruction. A stable low BMI could also be linked to reduced lung function caused by inadequate lung growth. In these cases, BMI was not normalised over the course of the study.

The study was based on the BAMSE project, in which over 4,000 children have been followed from birth to the age of 24. BMI has been repeatedly measured over this time, at most 14 times. The present study includes 3,200 participants with at least four BMI measurements.

Lung function was measured using spirometry at the ages of 8, 16 and, finally, 24, at which point the function of the smaller airways was also measured via the volume of exhaled nitrogen. Urine samples were also taken so that an analysis of the substances being metabolised could be performed in collaboration with docent Craig Wheelock at Karolinska Institutet's Institute of Environmental Medicine.

The urine samples from the high BMI group showed elevated levels of metabolites of the amino acid histidine, corroborating the observations of other researchers who found a similar increase in patients with asthma and chronic obstructive pulmonary disease.

Reference: https://news.ki.se/childrens-bmi-can-affect-their-future-lung-function