Obesity-Related Metabolic Syndrome and Vascular Complications

The epidemic of obesity, a condition defined as a body mass index (BMI) of 30.0 or more, has spread beyond the borders of high-income countries and is now dramatically on the rise also in low-and middle-income nations, particularly in urban settings [1]. One of the most concerning implications of this trend is the association between obesity and an increased risk of developing metabolic and cardiovascular disease in adults [2, 3] and in children [4–7]. Obesity, particularly when in a central body distribution, is frequently associated with the presence of the metabolic syndrome (MetS), a cluster of lipid abnormalities (i.e., elevated triglycerides and low HDL), hypertension, and impaired fasting glucose [8, 9]. Even if the MetS does not encompass risk factors that determine absolute risk (e.g., age, sex, cigarette smoking, and LDL cholesterol), it is associated with a twofold higher risk of cardiovascular disease (CVD) at 5 to 10 years and a 5-fold increase in risk to develop type 2 diabetes mellitus (T2DM) [8]. However, the definition of MetS and the associated CVD risk have been validated for mostly white cohorts and they may not be valid for different populations [10]. Numerous pathophysiological mechanisms have been proposed to link central adiposity, MetS, T2DM, and car-diovascular risk. In particular, adipose tissue dysfunction, insulin resistance/hyperinsulinemia, sympathetic hyperac-tivity, and endothelial dysfunction have emerged as pivotal players [11]. Adipose tissue dysfunction is characterized by the presence of an inflammatory infiltrate, adipokine dysreg-ulation, and release of inflammatory cytokines, which exert deleterious vascular effects in a systemic and paracrine fashion [12]. In turn, the abnormal vascular function may reduce skeletal muscle perfusion, thus worsening insulin sensitivity and establishing a self-perpetuating vascular-metabolic vicious cycle. However, our knowledge of the pathophysiol-ogy of vascular damage in obesity is still incomplete. A better mechanistic understanding could have important clinical implications, leading to the development of novel therapeutic strategies to reduce metabolic and cardiovascular risk in obesity. In this special issue, we have selected six papers investigating various aspects of the association between obesity-related metabolic syndrome and vascular complications. To address the scarcity of studies that have examined the relation between obesity and cardiometabolic risk factors (CRFs) in population-based samples of children and adolescents , T. Lyngdoh et al. assessed the association between BMI, measured both at the age of 12–15 years (longitudinal analysis) and at the present time (cross sectional analysis), and several CRFs in 390 young adults aged 19-20 years …