Insulin resistance (IR) in childhood plays a key role in the development of metabolic changes in adulthood, therefore, it is important to diagnose it early. We aimed to investigate studies that evaluated the TyG index for prediction of IR risk and other cardiometabolic risk factors, as well as, the proposed cutoff points in childhood and adolescence. This is a systematic review elaborated according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA). The search was performed in Lilacs, PubMed and CAPES Journal Portal, using the terms “TyG index OR triglyceride-glucose index OR triglyceride and glucose index AND children OR adolescent*”. Eight articles were included in this review. All were cross-sectional studies with individuals aged ≥2 and ≤20 years old, from the United States, Korea, Mexico, Brazil, and Iran. We concluded that the TyG index was positively associated with other IR prediction methods and appears to be advantageous for predicting IR risk and other cardiometabolic risk factors in children and adolescents (review registration: PROSPERO CRD42018100726).

Vitamin D deficiency is considered a global public health problem with high prevalence in children and adolescents. The majority of the studies in the literature have identified a relationship between vitamin D insufficiency/deficiency and obesity, as well as other traditional cardiometabolic risk factors in children and adolescents. Scarce studies address vitamin D status with oxidative stress and inflammation in the young population. The aim of this systematic review was to evaluate the evidence of the association of vitamin D status with oxidative stress and inflammation in children and adolescents. This is a systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guideline on reporting systematic reviews. Eight studies were selected for this review. All included studies evaluated inflammatory biomarkers and two out of eight evaluated biomarkers of oxidative stress. The majority of the studies (five out of eight) found association of vitamin D status with biomarkers of oxidative stress and inflammation such as C-reactive protein (CRP), interleukin-6 (IL-6), cathepsin S, vascular cell adhesion molecule-1 (VCAM-1), malondialdehyde (MDA), myeloperoxidase, 3-nitrotyrosine, and superoxide dismutase (SOD). Vitamin D status is associated with oxidative stress and inflammation in the majority of the studies with children and adolescents. Thus, the assessment of vitamin D status is important because it is associated with nontraditional cardiometabolic markers in the pediatric population (review registration: PROSPERO CRD42018109307).

Objective: To evaluate the ability of anthropometric measurements to identify excess android fat and to propose cut-off points for excess central adiposity in children, according to age and sex.Design: A cross-sectional study with children from a municipality of Minas Gerais, Brazil. Receiver-operating characteristic curve analyses were performed to evaluate waist circumference (WC), waist-to-height ratio (WHtR) and conicity index (C-index) in estimating excess android fat by dual energy X-ray absorptiometry (DXA).Setting: Viçosa, Minas Gerais, Brazil.Subjects: Children aged 4–9 years (n 788).Results: Overweight prevalence was 29·1 % and android fat percentage was higher among girls. All central fat measurements were able to discriminate excess android fat in the age groups evaluated, especially WC and WHtR, with cut-off points showing good sensitivity and specificity overall.Conclusions: Because these methods are easy to obtain and inexpensive, it is possible to use WC, WHtR and C-index in population surveys to evaluate central obesity. The proposed cut-off points showed satisfactory values of sensitivity and specificity and can be used in epidemiological studies.

Objective: To assess the prevalence of vitamin D insufficiency and deficiency and its association with cardiometabolic risk factors, controlled by adiposity, in a representative sample of prepubescent children.Design: Cross-sectional population-based study. Body composition was evaluated by dual-energy X-ray absorptiometry. Anthropometric measures and blood pressure were performed. Laboratory analyses were performed to determine the levels of vitamin D (25-hydroxyitamin D; 25(OH)D), glucose, insulin, serum lipids and intact parathyroid hormone. Dietary intake was assessed by three 24 h recalls.Setting: Viçosa, Minas Gerais, Brazil, 2015.Subjects: Representative sample of 378 children aged 8 and 9 years from urban schools.Results: Inadequate serum concentrations of 25(OH)D were diagnosed in more than half of the children and none of them met the recommended vitamin D intake. After adjusting for confounding factors in the multiple regression analysis, lower prevalence of insulin resistance and hypertriacylglycerolaemia was found in children with serum 25(OH)D levels ≥75 nmol/l (prevalence ratio=0·25; 95 % CI 0·08, 0·85) and ≥50 nmol/l (prevalence ratio=0·61; 95 % CI 0·37, 0·99), respectively. However, after adjusting for different indicators of adiposity, insulin resistance remained independently associated and the association with hypertriacylglycerolaemia was lost after adjusting for central adiposity. The prevalence of vitamin D insufficiency/deficiency was associated with the number of cardiometabolic alterations in children.Conclusions: The study results showed that prevalence of vitamin D insufficiency/deficiency was high among the children and insulin resistance was the main cardiometabolic alteration associated with this condition, even in a tropical climate country such as Brazil.

To evaluate the association of vitamin D intake with dyslipidaemia and vitamin D insufficiency/deficiency in Brazilian children and identify the main food group sources of this nutrient in the sample. A cross-sectional study carried out with a representative sample. Blood was collected after 12 h of fasting. Laboratory tests were performed to determine total cholesterol, HDL cholesterol (HDL-C), LDL cholesterol, TAG, apoB, apoA1, 25-hydroxyvitamin D and parathyroid hormone. Dietary intake was evaluated by a 24 h recall. Viçosa, Minas Gerais, Brazil. Children between 8 and 9 years old enrolled in urban schools (n 378). We found an elevated prevalence of inadequate vitamin D intake (91·3 %), dyslipidaemia (72·8 %) and vitamin D insufficiency/deficiency (56·2 %). The food groups that contributed the most to vitamin D intake were dairy products and fish. Lower vitamin D intake was associated with increased prevalence of both low HDL-C (prevalence ratio=2·51; 95 % CI 1·02, 6·18; P<0·05) and vitamin D insufficiency/deficiency (prevalence ratio=1·61; 95 % CI 1·01, 2·58; P<0·05). Given the elevated prevalence of inadequate vitamin D intake and its association with low HDL-C and vitamin D insufficiency/deficiency, it is important to develop specific actions in food and nutritional education as well as programmes that stimulate and facilitate access to vitamin D food sources, such as dairy products and fish.

C-reactive protein (CRP) is a marker of subclinical inflammation that has been found to be associated with cardiovascular disease risk. However, few studies have investigated the relationship between CRP and cardiometabolic markers in a representative sample of prepubescent children. The objective was to evaluate the high-sensitive CRP (hs-CRP) and its association with traditional and nontraditional cardiometabolic risk factors, as well as metabolic syndrome (MetS) components in Brazilian children. This is a cross-sectional representative study, with participants of the Schoolchildren Health Assessment Survey (PASE). Children from 8 to 9 years old (n=350) enrolled in public and private schools in the municipality of Viçosa, Minas Gerais, Brazil, were evaluated. Sociodemographic evaluation was performed through a semistructured questionnaire. Anthropometric, body composition, clinical, and biochemical measures were analyzed for cardiometabolic risk assessment. The total mean of serum hs-CRP concentration was 0.62 (±1.44) mg/L. hs-CRP was significantly correlated with several anthropometric, biochemical, and clinical parameters in this population (P<0.05). hs-CRP was positively associated with the accumulation of cardiometabolic risk factors and MetS components (P<0.05). Children with excessive weight; abdominal obesity; increased gynoid and android body fat; low HDL-c; hyperglycemia; and elevated uric acid, homocysteine, and apoB had higher chances of presenting increased hs-CRP (P<0.05). In this study, Brazilian children with cardiometabolic risk already presented elevated serum hs-CRP concentration. hs-CRP was associated with the increase of traditional and nontraditional cardiometabolic risk factors, as well as the accumulation of MetS components.