Pathophysiology of obesity and its associated diseases

The occurrence of obesity has increased across the whole world. Many epidemiological studies have indicated that obesity strongly contributes to the development of cancer, cardiovascular diseases, type 2 diabetes, liver diseases and other disorders, accounting for a heavy burden on the public and on health-care systems every year. Excess energy uptake induces adipocyte hypertrophy, hyperplasia and formation of visceral fat in other non-adipose tissues to evoke cardiovascular disease, liver diseases. Adipose tissue can also secrete adipokines and inflammatory cytokines to affect the local microenvironment, induce insulin resistance, hyperglycemia, and activate associated inflammatory signaling pathways. This further exacerbates the development and progression of obesity-associated diseases. Although some progress in the treatment of obesity has been achieved in preclinical and clinical studies, the progression and pathogenesis of obesity-induced diseases are complex and unclear. We still need to understand their links to better guide the treatment of obesity and associated diseases. In this review, we review the links between obesity and other diseases, with a view to improve the future management and treatment of obesity and its co-morbidities.