Outcomes in metabolically healthy obese children and adolescents
Childhood obesity is associated with metabolic complications such as insulin resistance, hypertension, dyslipidemia and inflammation, which may eventually lead to the development of cardiovascular disease (CVD) and type 2 diabetes. Nonetheless, some obese children do not show any of these cardiometabolic disturbances, and they are called metabolically healthy obese (MHO).
It has been suggested that 30% of obese adult patients are metabolically healthy, and that this group have similar insulin sensitivity to lean individuals, lower visceral and liver fat and lower intima media thickness of the carotid artery (cIMT) compared with metabolically unhealthy obese (MUO) patients. Thus, MHO phenotype basically refers to obese individuals who might not be at an increased risk of CVD. Recently, however, several papers have focused on the dangers and long-term outcomes of the MHO phenotype. Indeed, it has been shown that a high number of subjects with MHO eventually develop metabolic unhealthiness or metabolic unhealthy obesity over time, that subjects with MHO still have an increased risk of CVD, particularly heart failure, and even coronary heart disease, and that MHO phenotype MHO is still associated with future risk of metabolic syndrome and CVD.
Whether MHO is associated with subclinical signs of organ damage, such as hepatic steatosis, subclinical atherosclerosis and LVH remains to be determined in childhood. This is an important issue in light of the role of fatty liver disease and subclinical cardiovascular changes (atherosclerosis and cardiac structural abnormalities) as predictors of CV events. Therefore the objectives of the present research will be to assess in a large population of overweight/obese youth, whether MHO is associated with signs of organ damage, in comparison with age- and gender-matched normal weight subjects.