Fatness, Fitness, and Cardiometabolic Risk Factors among Sixth-Grade Youth

Abstract

Purpose Examine whether cardiometabolic risk factors are predicted by fitness or fatness among adolescents. Methods Participants are 4955 (2614 female) sixth-grade students with complete data from 42 US middle schools. Fasting blood samples were analyzed for total cholesterol, HDL- and LDL-cholesterol, triglyceride, glucose, and insulin concentrations. Waist circumference and blood pressure were assessed. Body mass index (BMI) was categorized as normal weight, overweight, or obese as a measure of fatness. Fitness was assessed using the multistage shuttle test and was converted into gender-specific quintiles. Gender-specific regression models, adjusted for race, pubertal status, and household education, were run to identify whether BMI group predicted risk factors. Models were repeated with fitness group and both fitness and fatness groups as predictors. Results Means for each risk factor (except HDL, which was the reverse) were significantly higher (P < 0.0001) with increased fatness and differed across all BMI groups (P < 0.001). Waist circumference, LDL-cholesterol, triglycerides, diastolic blood pressure, and insulin were inversely associated with fitness (P < 0.001). When both fatness and fitness were included in the model, BMI was associated (P < 0.001) with almost all cardiometabolic risk factors; fitness was only associated with waist circumference (both genders), LDL-cholesterol (males), and insulin (both genders). Other associations between fitness and cardiometabolic risk factors were attenuated after adjustment for BMI group. Conclusions Both fatness and fitness are associated with cardiometabolic risk factors among sixth-grade youth, but stronger associations were observed for fatness. Although maintaining high levels of fitness and preventing obesity may positively affect cardiometabolic risk factors, greater benefit may be obtained from obesity prevention.

Obesity as a Mediator of the Influence of Cardiorespiratory Fitness on Cardiometabolic Risk: A Mediation Analysis

“…CRF levels have proven to be an independent predictor for MetS in children and adolescents (8,(13)(14)(15). Consistent with previous studies, our data showed that as CRF levels increased, the metabolic risk profile improved (10,14), but when the influence of BMI was controlled, the association between CRF and cardiometabolic risk factors disappeared or was mitigated (13,15).…”

“…In most of the studies reported to date, CRF appears to be independently associated with cardiometabolic risk even after adjusting for adiposity, although the magnitude of the association appears to be small to moderate when adiposity is included in the models (9,15). Likewise, CRF levels do not completely account for the association between BMI and cardiometabolic risk (15,16).…”

Factors associated with serum lipids of adolescents from the Brazilian South

“…Similar results were reported elsewhere 9,14 suggesting that excess weight during adolescence may be associated with undesirable total cholesterol levels. On the other hand, other studies have not found an association between BMI and cholesterol in adolescents 15,25 .…”

“…Similar variations have been found in other countries 10,11 . Many factors have been associated with dyslipidemia in adolescents, such as socio-environmental conditions, behavior patterns, genes, low birth weight, and excess weight 8,[12][13][14][15][16] . Nevertheless, only a few studies explore the relationship between serum lipids and anthropometric and lifestyle variables, considered important confounding factors.…”

Sleep Duration and Obesity of Young Mexican-heritage Children in Rural California

“…One in three children in the United States is overweight or obese and at-risk for metabolic or cardiac disease [1,2]. Modifiable lifestyle risk factors such as physical activity and diet are common targets of intervention [3][4][5].…”