Somatotypes trajectories during adulthood and its association with Chronic Obstructive Pulmonary Disease (COPD) phenotypes

Abstract Background Chronic obstructive pulmonary disease (COPD) comprises distinct phenotypes, all characterized by airflow limitation. Research Question We hypothesized that somatotype changes -as surrogate of adiposity- from early adulthood follow different trajectories to reach distinct phenotypes. Methods Using the validated Stunkard’s pictogram, 356 COPD patients chose the somatotype that best reflects their current body build and those at ages 18, 30, 40 and 50. An unbiased group-based trajectory modelling was used to determine somatotypes trajectories. We then compared the current COPD related clinical and phenotypic characteristics of subjects belonging to each trajectory. Results At age 18, 88% of the participants described having a lean or medium somatotype (estimated BMI between 19-23 kg·m −2 )while the other 12% a heavier somatotype (estimated BMI between 25-27 kg·m −2 ). From age 18 onwards, five distinct trajectories were observed. Four of them demonstrating a continuous increase in adiposity throughout adulthood with the exception of one, where the initial increase was followed by loss of adiposity after age 40. Patients with this trajectory were primarily females with low BMI and DLCO. A persistently lean trajectory was seen in 14% of the cohort. This group had lower FEV 1 , DLCO, more emphysema and worse BODE score thus resembling the Multiple Organ Loss of Tissue (MOLT) phenotype. Conclusions COPD patients have distinct somatotype trajectories throughout adulthood.Those with the MOLT phenotype maintain a lean trajectory throughout life. Smoking subjects with this lean phenotype in early adulthood deserve particular attention as they seem to develop more severe COPD.