Normal quantities of adipose tissue are required in humans, as adipose tissue
stores energy and contributes to endocrine and immune functions. Hormones and
cytokines secreted by the adipose tissue, collectively known as ‘adipokines’, include
adiponectin, leptin, tumor necrosis factor-α, interleukin 6, and plasminogen activator
inhibitor-1. These secretory products play important roles in the maintenance of glucose
and energy homeostasis. Both excess and deficiency of adipose tissue can have a
negative impact metabolically. In the lipodystrophy syndromes, there is partial or
complete loss of adipose tissue, which can lead to insulin resistance, diabetes and
hepatic steatosis. Malnutrition due to starvation and anorexia nervosa has also been
associated with manifestation of diabetes. In contrast, excess of adipose tissue in obesity
has also been associated with insulin resistance, diabetes, fatty liver and cancer. With
obesity on the rise globally, non-communicable diseases including cardiovascular
disease, cerebrovascular disease, diabetes mellitus, dementia, cancer, and fatty liver
disease have increased dramatically in prevalence and are rapidly becoming leading
causes of death around the world. Thus, a normal amount and distribution of adipose
tissue is required to achieve optimal regulation of metabolism and general good health.
Keywords: Adipose tissue, diabetes, insulin resistance, lipodystrophy,
malnutrition, metabolism, obesity, starvation.
