The influence of somatic maturity on the relationship between the triglyceride/high-density lipoprotein ratio and vascular health in children and adolescents with dyslipidemia.

INTRODUCTION: Both the triglyceride to HDL cholesterol (TG/HDL) ratio and timing of pubertal maturation have been identified as independent contributors to the development of atherosclerosis. OBJECTIVE: The purpose of our study was to determine the relationship between the TG/HDL ratio and measures of vascular health in children and adolescents with dyslipidemia stratified by somatic maturity. We hypothesized that somatic maturity would have a significant interaction with TG/HDL ratio and vascular health. METHODS: This was a longitudinal analysis of 120 children and adolescents (age 8-14 years) with dyslipidemia recruited from a pediatric preventive cardiology clinic. At baseline and each follow-up visit, a non-fasting serum lipid panel was collected and vascular health (carotid artery intima--media thickness, pulse wave velocity, augmentation index) was assessed. Peak height velocity (PHV) was calculated at each visit, and participants were stratified into groups by maturity offset (pre-PHV, mid-PHV, post-PHV). A mixed model design permitted baseline and follow-up visits to be classified as discrete data points. RESULTS: Of the n = 235 data points (pre-PHV = 23%, mid-PHV = 19%, and post-PHV = 58%), we identified no significant interaction between TG/HDL ratio, maturity offset, and measures of vascular structure or function. There was also no significant relationship found between TG/HDL and maturity group. Within the mid-pubertal group, there was weak relationship found between TG/HDL and augmentation index. CONCLUSION: Despite the well-described relationship between early pubertal maturation and development of cardiovascular risk factors in adulthood, we found that vascular damage resulting from an elevated TG/HDL ratio is not independently associated with somatic maturity.

Early cardiac dysfunction in obese adolescents with Down syndrome or autism.

BACKGROUND: Obesity in adolescents with intellectual and developmental disabilities) occurs at twice the frequency as their typically developing peers. Typically developing adolescents with obesity have abnormal cardiac function (as measured by strain echocardiography) and cardiac mass, but the effects of obesity on cardiac health in adolescents with Down syndrome or autism spectrum disorder are unknown. The purpose of this study was to evaluate the impact of body mass index on cardiac function in adolescents with Down syndrome or autism. METHODS: Adolescents (age 12-21 years) with Down syndrome (n = 28), autism (n = 33), and age-/sex-matched typically developing controls (n = 15) received an echocardiogram optimised for strain analysis at a single timepoint. Measures of ventricular function, mass, and size were collected. Regression modelling evaluated the impact of body mass index and intellectual and developmental disabilities diagnosis on these cardiac measures. RESULTS: In regression modelling, an elevated body mass index z-score was associated with diminished systolic biventricular function by global strain (left ventricular longitudinal strain ß 0.87, P < 0.001; left ventricular circumferential strain ß 0.57, p 0.003; right ventricular longitudinal strain ß 0.63, P < 0.001). Diminished left ventricular diastolic function by early diastolic strain rate was also associated with elevated body mass index (global longitudinal end-diastolic strain rate ß -0.7, P < 0.001). No association was found between traditional (non-strain) measures of systolic and diastolic ventricular function and body mass index z-score. CONCLUSIONS: Obesity in adolescents with Down syndrome or autism negatively impacts cardiac function as measured by echocardiographic strain analysis that was not detected by traditional parameters.