New aspects of cellular cholesterol regulation on blood glucose control- review and perspective on the impact of statin medications on metabolic health

Cholesterol is an essential component of cell membranes, and during the past several years, diabetes researchers have found that membrane cholesterol levels in adipocytes, skeletal muscle fibers and pancreatic beta cells influence insulin action and insulin secretion. Consequently, it is thought that dysregulated cell cholesterol homeostasis could represent a determinant of type 2 diabetes (T2D). Recent clinical findings compellingly add to this notion by finding increased T2D susceptibility in individuals with alterations in a variety of cholesterol metabolism genes. While it remains imperfectly understood how statins influence glucose metabolism, the fact that they display an influence on blood glucose levels and diabetes susceptibility seems to intensify the emerging importance of understanding cellular cholesterol in glucose metabolism. Taking this into account, this review first presents cell system and animal model findings that demonstrate the negative impact of cellular cholesterol accumulation or diminution on insulin action and insulin secretion. With this framework, a description of how changes in cholesterol metabolism genes are associated with T2D susceptibility will be presented. In addition, the connection between statins and T2D risk will be reviewed with expanded information on pitavastatin, a newer statin medication that displays actions favoring metabolic health