Perivascular adipose tissue: epiphenomenon or local risk factor?

Obesity is associated with an increased cardiovascular risk, but the mechanisms underlying the link between increased body weight and vascular disease are incompletely understood. Over the past 15 years, perivascular adipose tissue has emerged as active component of the vessel wall involved in vascular homeostasis. However, perivascular adipose tissue can adopt detrimental properties under the influence of obesity and other factors and contribute actively to the pathophysiology of cardiovascular disease. Conversely, changes of the vessel wall may negatively affect perivascular adipose tissue qualities. In this review, we will discuss the recent literature on the possible direct and indirect connections between perivascular fat alterations and cardiovascular pathologies. In addition to clinical evidence on the association between perivascular fat mass and morphology and anthropometric measures of obesity or the reciprocal connection between perivascular fat and cardiometabolic risk factors and disease, special emphasis will be placed on results in rodent and other models and the possible direct contribution of local fat depots to vascular dysfunction, neointima formation or atherosclerosis. We will briefly highlight results from human and murine genome, miRNome and proteome-wide expression analyses of potential candidate mediators involved in its paracrine activities and present data on how the cardiovascular risk factors obesity, age or diabetes, but also the preventive measures weight loss or exercise impact on perivascular expression patterns. A better understanding of this unique adipose tissue depot, its properties and regulatory mechanisms, may create opportunities for novel diagnostic and therapeutic strategies to combat the cardiovascular consequences of increased body weight.