Relationship between commonly defined metabolic health phenotypes and obesity with lung function in a working population: A cross-sectional study.

BACKGROUND: Four phenotypes relate metabolism and obesity: metabolically healthy (MHO) and unhealthy (MUO) people with obesity and metabolically healthy (MHNO) and unhealthy (MUNO) people without obesity. No studies have addressed the association between these categories and lung function in the working population.

OBJECTIVES: The aim was to determine the relationship of phenotypes to lung ageing as measured by lung age and its relationship to lung dysfunction.

METHODS: A descriptive cross-sectional study was conducted in a working population. The outcome variable was lung function assessed by lung age. The four phenotypes of obesity and metabolic health (MHNO, MHO, MUO and MUNO) were determined using NCEP-ATP III criteria. Lung dysfunctions were classified into restrictive, obstructive, and mixed patterns.

RESULTS: The mean age of the participants was 43.7 years, ranging from 18 to 67 years. Of the 1860 workers, 51.3 % were women. The prevalences found were 71.4 %, 12 %, 10.6 % and 6 % for MHNO, MUO, MHO, and MUNO, respectively. MHO (β = 0.66; p = 0.591) was not associated with increased lung ageing compared with MHNO, but MUO (β = 7.1; p < 0.001) and MUNO (β = 6.6; p < 0.001) were. Concerning pulmonary dysfunctions, MUNO (OR = 1.93; p < 0.001) and MUO (OR = 2.91; p < 0.001) were found to be related to the presence of a restrictive pattern, and MUNO (OR = 2.40; p = 0.028) to the mixed pattern.

CONCLUSION: The results show that metabolic abnormalities, not obesity, are responsible for premature lung ageing and, therefore, lung function decline. In our study, having obesity without metabolic abnormality was not significantly associated with the presence of dysfunctional respiratory patterns.