The burden of overweight and obesity has reached epidemic levels globally. According to the World Health Organization in 2014, more than 1.9 billion adults and 41 million children under the age of 5 years were overweight. Overweight and obesity are major risk factors for non-communicable diseases such as cardiovascular diseases or diabetes. More recently, overweight and obesity have been longitudinally associated with decreased pulmonary function parameters. Furthermore, a relationship between chronic obstructive pulmonary disease (COPD) and obesity has been recognized in the last years. However, previous studies are limited by a lack of repeated measures on lung function and by a lack of control for potential confounders, such as physical activity and diet. Also, to date, studies have used body mass index (BMI) as the main measure of overweight and obesity, although it has been recently suggested that body composition would be a better marker because of the potential different effects of fat mass and lean body mass on lung function. Fat mass has been shown to have a negative effect on lung function whereas lean mass positively influences respiratory function.
Thus the main objective of my PhD project is to assess the effect of body weight and composition on lung function development in adolescents and decline in adults. To accomplish the main objective, a longitudinal study of multiple cohorts, around Europe and Australia, will be performed. This study is part of the Aging Lungs in European Cohorts (ALEC) project which aims to improve our understanding of the determinants and risk factors for low lung function, respiratory disability and the development of COPD.
At a clinical level, the results of my PhD project will contribute to the inclusion of nutritional counseling for weight loss in clinical practice guidelines of COPD. At a health policy level, it is expected that our results, in combination with the existing research on the role of physical activity and diet in COPD, will result in lifestyle promotion programs adapted to different stages of life.