Obesity Paradox in Lung Diseases: What Explains It?

Abstract

<b><i>Background:</i></b> Obesity is a globally increasing health problem that impacts multiple organ systems and a potentially modifiable risk factor for many diseases. Obesity has a significant impact on lung function and is strongly linked to the pathophysiology that contributes to lung diseases. On the other hand, reports have emerged that obesity is associated with a better prognosis than for normal weight individuals in some lung diseases, including pneumonia, acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, and lung cancer. The lesser mortality and better prognosis in patients with obesity is known as obesity paradox. While obesity paradox is both recognized and disputed in epidemiological studies, recent research has suggested possible mechanisms. <b><i>Summary:</i></b> In this review, we attempted to explain and summarize these factors and mechanisms, including immune response, pulmonary fibrosis, lung function, microbiota, fat and muscle reserves, which are significantly altered by obesity and may contribute to the obesity paradox in lung diseases. We also discuss contrary literature that attributes the “obesity paradox” to confounding. <b><i>Key Messages:</i></b> The review will illustrate the possible role of obesity in the prognosis or course of lung diseases, leading to a better understanding of the obesity paradox and provide hints for further basic and clinical research in lung diseases.

Tamping Down the Fire: Taming Pyroptosis through RNA Methylation in Acute Lung Injury

“…SNPs in the first intron of the FTO gene are associated with predisposition to both childhood and adult obesity ( 14 – 16 ). Although obese people exhibit higher morbidity associated with ARDS and are more likely to be hospitalized, they are paradoxically protected from mortality—the so-called “obesity paradox” ( 17 ). It is unknown how these FTO variants affect the methylation of individual RNAs or regulate gene expression programs that may affect responses to lung injury.…”