The Adipose Tissue

Abstract

The adipose tissue, long studied as an energy storage depot and structural tissue, is a key player in maintaining energy homeostasis. Additionally, through its endocrine functions, adipose impacts a wide variety of systems in the body. Adipose is a unique organ in that its mass can vary drastically between individuals, from under 5% of body mass in elite athletes to well over half of body mass in the morbidly obese. Because the range of systems affected by adipose are so broad, it follows that over or under accumulation of this tissue can have vast and important medical consequences. Obesity increases risk for diseases such as type 2 diabetes, high blood pressure, coronary atherosclerosis, gout, cancer, gall bladder disease, sleep apnea, and degenerative arthritis. Lipodystrophy also increases risk for type 2 diabetes. In the US, it is estimated that over 100,000 people die of overweight and obesity related causes each year. Two-thirds of the US population is overweight, and one-third is obese. This raises many questions: What do we know about fat development? What cell or cells give rise to adipose and what triggers this event? The myriad of roles that adipose tissue plays in the body, as well as the increasing relevance of understanding adipose as it relates to obesity, demonstrate the importance of better understanding this tissue. This article aims to provide the reader with an understanding of adipose on a developmental and functional level, as well as present the open questions in the field.