Obesity and cardio-metabolic risk factors in children aged 2--18 years attending a childhood obesity program in central Texas

The prevalence of childhood obesity, including severe obesity has increased markedly over the past 30 years, with significant racial/ethnic disparities evident among children and adolescents of Hispanic and Black origin. Paralleling the increase in obesity among children and adolescents is an increase in prevalence of cardiovascular risk factors. Obese children are at an increased risk for cardiovascular diseases, type 2 diabetes mellitus, and all-cause mortality both during their childhood and adult life. The objective of the current study was to examine the association between obesity and cardio-metabolic risk factors in a racially and ethnic diverse sample of children aged 2-18 years attending the ACES Obesity clinic of Dell Children\u27s Medical Center of Central Texas over a time period spanning from 2010-2012. The study was a secondary data analysis of the ACES database utilizing a cross-sectional study design. The exposure variable was obesity status classified as severe obesity (defined as BMI-for-age percentile at or above 99th and overweight/simple obesity (defined as BMI-for-age percentile between 85th and less than 99th percentile). The outcome variables were cardio-metabolic risk factors including systolic blood pressure, diastolic blood pressure, fasting blood glucose, and blood lipid profile. Linear regressions adjusted for demographic variables including age, race/ethnicity, and gender were run to examine these associations; in additional analyses, the demographic variables were included as effect modifiers. Results showed significant differences in the prevalence of overweight/simple obesity and severe obesity by age groups, but not by race/ethnicity and gender. Severely obese children had higher levels of mean systolic blood pressure, mean diastolic blood pressure and lower blood high-density lipoprotein level, after adjusting for demographic variables, reflecting that this population faces potentially higher health risks. Overall, there was no evidence of an interaction of obesity status with age group, race/ethnicity and gender in determining levels of cardio-metabolic risk factors (except for fasting blood glucose level). Some differences across obesity levels in systolic blood pressure, diastolic blood pressure and high-density lipoprotein level were evident for specific age, race and gender groups, but these were not consistent or systematic. This study emphasizes the importance of further classification of obesity beyond conventional categories in this population by showing that health risks differ between children and adolescents who are simply obese versus those who are severely obese. The lack of interaction between obesity and demographic factors in level of cardio-metabolic risk factors is an important finding, because it underscores that severely obese children are at higher risk of cardio-metabolic diseases, regardless of age, sex or race, and that clinicians need to take this into account when developing treatment plans. For future studies, we recommend conducting a prospective study with a larger sample that will help to detect the differential development of these risk factors by levels of obesity.