Two‐sided roles of adipose tissue: Rethinking the obesity paradox in various human diseases from a new perspective

Abstract

Summary Overweight and obesity, as a result of excess fat accumulation, have become a worldwide public health issue. Recent studies have shown that obesity is closely related to many human diseases, such as cancer, cardiovascular diseases, and type 2 diabetes mellitus, in which adipose tissue plays a dual role. In addition to thermal and mechanical insulation and a critical role in energy storage and heat production, adipose tissue is also a highly plastic endocrine and signaling organ that secretes multiple bioactive molecules for inter‐organ crosstalk. The phenotypic and biological changes of adipose tissue under pathological conditions, especially in obesity, increase the challenge of deciphering the positive or negative effects of adipose tissue in disease. Despite numerous studies on obesity and adipose tissue, the ambiguous role of adipose tissue on specific organs or tissues in different diseases is not fully understood, and the definite mechanisms remain obscure. In this review, we first summarize the basic biological characteristics of adipose tissue in the physiological state and the abnormal remodeling of adipose tissue during obesity. We then discuss the complex and disparate effects of obesity on various human diseases, with a particular focus on the dual roles and underlying mechanisms of adipose tissue, a quintessential player in obesity, in this process. More importantly, rethinking the causes of the “obesity paradox” phenomenon in diseases from the perspective of adipose homeostasis and dysfunction provides a novel strategy for disease treatment by intervening in fat function.

Impact of Epicardial Adipose Tissue on Infarct Size and Left Ventricular Systolic Function in Patients with Anterior ST-Segment Elevation Myocardial Infarction

“…In patients with large infarctions, however, high EAT and greater subsequent EAT reduction correlates with more preserved LVEF in the chronic phase (Figure 10). In the specific post-infarction setting, this dual and paradoxical influence of EAT somehow resembles the obesity paradox and its yin-yang effects in the field of cardiovascular diseases [13].…”

Impaired Remodeling of White Adipose Tissue in Obesity and Aging: From Defective Adipogenesis to Adipose Organ Dysfunction

“…The AT is able to adapt and respond to internal and environmental stimuli by remodeling both its cellular and extracellular components, which makes it a key player in health and disease [7]. This ability to undergo phenotypic, metabolic, and structural adaptations is called AT plasticity [8].…”