RESUMO
BACKGROUND: The age of onset of hypertension (HTN) is decreasing, and obesity is a significant risk factor. The prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently studied. This study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and HTN. METHODS: Seven thousand, five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8-18 years from the 2013-2015 China Child and Adolescent Cardiovascular Health study and the 2011-2018 National Health and Nutrition Examination Surveys were analyzed. Blood pressure and body composition (fat and muscle) were measured by trained staff. The crude prevalence and age-standardized prevalence rate (ASPR) of primary HTN and its subtypes [isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH)] were calculated based on 2017 American Academy of Pediatrics guidelines. Multivariable-adjusted linear regression coefficients and odds ratios (ORs) were calculated to assess the associations of body composition indicators with HTN, ISH and IDH. RESULTS: The ASPR of HTN was 18.5% in China (CN) and 4.6% in the United States (US), whereas the obesity prevalence was 7.4% and 18.6%, and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in CN. Increased fat mass, muscle mass and body fat percentage mass were associated with a higher risk of HTN in both countries. The percent of muscle body mass had a protective effect on HTN and ISH in both countries [HTN (CN: OR = 0.83, 95% CI = 0.78-0.88; US: OR = 0.72, 95% CI = 0.64-0.81); ISH (CN: OR = 0.87, 95% CI = 0.80-0.94; US: OR = 0.71, 95% CI = 0.62-0.81)], and the protective effect was more common among children and adolescents with high levels of physical activity. CONCLUSIONS: The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US, and the contribution of obesity to HTN was higher in the US than in CN. Augmenting the proportion of muscle mass in body composition has a protective effect against HTN in both populations. Optimizing body composition positively influences blood pressure in children and adolescents, particularly those with high-level physical activity. Video abstract (MP4 149982 KB).
RESUMO
OBJECTIVE: To determine the prevalence of nonalcoholic fatty liver disease (NAFLD) and metabolic abnormalities in obese children and adolescents in Beijing. METHODS: This study involved 387 obese children and adolescents, aged 12 to 17 years in Beijing. Data on anthropometric measurements was collected, including weight, height and age. All subjects underwent a clinic examination containing fasting blood and liver ultrasonography. Nonalcoholic fatty liver disease was diagnosed using diagnostic criteria for nonalcoholic fatty liver disease which was recommended by the Fatty liver and Alcoholic Liver Disease Study Group of Liver Disease Association in China. RESULTS: 174 out of the 387 children were diagnosed as having NAFLD. The overall prevalence of NAFLD was 45.0% in this study population. The prevalence rates of NAFLD did not show significant difference between girls and boys. The prevalence rates of diabetes mellitus and IFG were 0.8% and 49.1% respectively. The prevalence rates of HTG, HTC, HLDL-C, LHDL-C, IFG, elevated ALT (or AST) and acanthosis nigricans were 6.3%, 4.0%, 37.9%, 22.8%, 46.0%, 17.8% and 28.5% in students combined with obesity and NAFLD, respectively. In the NAFLD subgroup, higher prevalence of high TG, acanthosis nigricans, abnormal ALT or AST were seen. With the increasing of obesity, the level of LDL-C, TG, liver function disturbance and prevalence of NAFLD and acanthosis nigricans were aggravated. Under binary logistic regression analysis, results showed that high BMI, acanthosis nigricans and TG were significantly correlated with NAFLD in obese children and adolescent population. CONCLUSION: NAFLD was common in obese children, and the prevalence of NAFLD in obese children was 45.0%. Higher BMI, acanthosis nigricans and abnormal TG were independent risk factors for NAFLD in obese children. Obese children who had been exposed to high risk factors should take the ultrasonography.
