White adipose tissue expansion as the driver of insulin resistance and secondary endocrine disturbances in obesity- a narrative review.

Obesity represents a rapidly growing and alarming global health issue, with its prevalence nearly tripling over the past four decades. White adipose tissue enhances fat storage by increasing adipocyte size (hypertrophy) or recruiting new adipocytes (hyperplasia). The imbalance between adipocyte hyperplasia and hypertrophy, visceral adiposity, and dysfunction of white adipose tissue, rather than total fat mass, better predicts insulin resistance (the most common hormonal alteration in obesity) and related complications. Moreover, abdominal adiposity is a significant determinant of hormonal disturbances that link obesity to thyroid, adrenal, and gonadal dysfunctions. In addition, alterations in the physiology of hormones regulating food intake (leptin, ghrelin, incretins) are incontestably present in obesity. Importantly, weight loss can help restore metabolic and hormonal imbalances. This review summarizes the selected hormonal disturbances associated with white adipose tissue expansion.