Obesity and the Metabolic Syndrome in Children and Adolescents.

摘要

The metabolic syndrome is a link between insulin resistance and, among other conditions, hypertension, dyslipidemia, and type 2 diabetes. Obesity, the most common cause of insulin resistance in children, also is associated with dyslipidemia and type 2 diabetes as well as vascular complications later in life. This study attempted to relate varying degrees of obesity to the prevalence of the metabolic syndrome. High C-reactive protein (CRP) and interleukin-6 (IL-6) levels and low levels of adiponectin, which are independent risk factors for atherosclerosis in obese, insulin-resistant adults, were sought in 439 obese children and adolescents ranging in age from 4 to 20 years whose body mass indices exceeded the 97th percentile for age and sex. Also studied were 31 overweight and 20 nonobese individuals. Participants consumed at least 250 g of carbohydrates daily for 3 days before the study.Blood levels of glucose, insulin, triglycerides, and IL-6 all rose with increasing obesity, as did the risk of insulin resistance, systolic blood pressure, and impaired glucose tolerance. At the same time, levels of high-density lipoprotein and adiponectin declined. The proportion of subjects with impaired glucose tolerance increased directly with the degree of obesity in all racial and ethnic groups, and this remained the case after adjusting for sex and pubertal status. Metabolic syndrome was diagnosed in 39% of moderately obese and 50% of severely obese subjects. No nonobese or overweight individual met criteria for metabolic syndrome. Three factors-obesity and glucose metabolism, degree of dyslipidemia, and blood pressure-explained 58% of total variance in the data. The prevalence of metabolic syndrome rose significantly with increasing insulin resistance after adjusting for race, ethnic background, and degree of obesity. CRP levels correlated significantly with the degree of obesity but not with the level of insulin resistance. Adiponectin levels declined with increasing obesity. Levels of IL-6 increased significantly with the degree of obesity and correlated with CRP levels but not with the degree of insulin resistance. Ten of 34 subjects who were followed up for a mean of 21.5 months no longer met criteria for the metabolic syndrome. The syndrome developed in 16 of 43 children who did not have it at baseline.Metabolic syndrome appears to be much more frequent in children and adolescents than formerly thought. Its prevalence increases directly with the degree of obesity, and each element of the syndrome becomes worse with increasing obesity. Over time, the syndrome tends to progress clinically. Conceivably, these findings anticipate an epidemic of advanced cardiovascular disease.