Oxidative Stress and Biochemical Parameters in Childhood Obesity

Research Article

Austin J Nutri Food Sci. 2018; 6(1): 1097.

Oxidative Stress and Biochemical Parameters in Childhood Obesity

Marcela AS¹*, Tarraf HS², Nicoletti CF¹, Percário S³, Oliveira BAP¹, Oliveira CC¹, Gregório ML², Pinhanelli VC² and Dorotéia RS²

¹Department of Internal Medicine, Faculty of Medicine of Ribeirao Preto, University of São Paulo Ribeirão Preto, Brazil

²Department of Molecular Biology, Faculty of Medicine of São Jose do Rio Preto. São Jose do Rio Preto - SP, Brazil

³Research on Oxidative Stress Laboratory, Federal University of Pará. Belém, Brazil

*Corresponding author: Marcela Augusta de Souza Pinhel, DepartmentofInternal Medicine, Ribeirao Preto Medical School, Universityof São Paulo, Ribeirão Preto - SP, Brazil. Avenida dos Bandeirantes, 3900. Ribeirao Preto, SP, Brazil

Received: January 08, 2018; Accepted: February 02, 2018; Published: February 20, 2018


Aim: Obesity in children has been associated with increased oxidative stress a factor that may play a key role in the pathophysiology of cardiovascular and metabolic events of obesity. The main aim this study was to analyze risk predictors for Cardiovascular Disease (CVD) including lipid profile and oxidative stress in children with and without obesity and the correlation between sedentary lifestyle and breastfeeding history.

Methods: Were enrolled 66 children randomized into two groups: G1: 35 children with obesity and G2: 31 children with normal weight. Anthropometric, biochemical, personal and family history data were collected, besides a peripheral blood sample. Statistical analysis included t, Fisher tests and Pearson correlation. Significance level was assumed for p<0.05.

Results: The mean age of G1 was 8±1.5 years and Body Mass Index (BMI) of 25.6±2.5 kg/m². For G2 mean age of 7±1.4 years and BMI 16.5±1.4 kg/m². It was observed that G1 had higher TG and malondialdehyde (MDA) levels compared to G2 (p<0.05). It was noted positive correlation between MDA levels, TG and VLDLc only in the obese group (p<0.0001). Children with normal weight and breastfeeding have higher levels of HDLc.

Conclusion: High levels of TG and MDA are associated with obesity. Breastfeeding history associated with high levels of HDLc in normal weight children, suggests its protective effect for CVD. We suggest that pediatricians should be aware of the importance of assessing the degree of oxidative stress in children with obesity in an attempt to prevent the development of comorbidities.

Keywords: Oxidative stress; Obesity; Childhood; Cardiovascular diseases


The increase in the number of children with obesity is a major health problem, mainly because of its association with comorbidities, including atherosclerosis and type 2 diabetes mellitus; factors that can lead the development of cardiovascular disease [1]. It is estimated that in Brazil the prevalence of childhood obesity is approximately 16.6% in boys and 11.8% in girls, probably due to high consumption of highcalorie foods and beverages and reduced physical activity [2].

Obesity in children is one of the risk factors for obesity in adults and for the development of chronic diseases during childhood and adulthood [3]. Cardiovascular Diseases (CVD) are responsible for high mortality in Brazil, requiring further clarification, especially in children. There is an association between plasma cholesterol levels and mortality from cardiovascular disease [4], and among the main risk factors for CVD are high concentrations of low-density lipoprotein (LDLc) and low concentrations of high-density lipoprotein (HDLc) [5].

Moreover, other mechanisms that link obesity to the CVD have been widely investigated and include the state of inflammation and oxidative stress resulting from the increased adipose tissue [5,6]. Thus, obesity in children has been associated with increased oxidative stress [7], a generated condition when the production of reactive oxygen species exceeds the body’s ability to remove them. Thus, the increased oxidative stress may play a key role in the pathophysiology of cardiovascular and metabolic events of obesity8 and contributing to the development of obesity-related comorbidities [8].

However, the oxidative process remains to be elucidated. The investigation of biomarkers may contribute to early diagnosis of the implications of childhood diseases. It limited the number of studies on the oxidative damage caused by obesity in childhood; however associations between oxidative stress and diseases related to obesity, such as hypercholesterolemia [9] and insulin resistance [10] are being reported in children.

In this context, the present study aimed to analyze risk predictors for CVD including lipid profile and oxidative stress in children with and without obesity by sex and age and the correlation between the presences or absence of a sedentary lifestyle, breastfeeding history and background family of CVD.

Material and Methods

For the present study, 66 children with age between 5 and 10 years, of both sexes were enrolled in a Basic Health Unit Care. It is case-control study in which children were randomized into two groups according to nutritional status: Group 1 (G1): 35 children with obesity and Group 2 (G2): 31 children with normal weight. Children with heart diseases, metabolic diseases, and genetic disorders associated with dyslipidemia and in use of medication were excluded. This study was approved by the Ethics Committee of the institution. Parents or guardians were informed about the study and their consent was obtained.

Anthropometric, biochemical and personal and family history data were collected in a single moment. The anthropometric assessment was based on measurements of weight and height and calculate Body Mass Index (BMI). Weight was measured with a mechanical scale (capacity of 150 kg and 0.1 kg of precision) and height was measured with vertical stadiometer (graduation 0.1 cm). BMI (kg/m2) was calculated by the formula weight (kg) / height2 (m) and their values applied in graphic NCHS (National Center for Health Statistics) [11] according to gender and age to determine the nutritional status. For evaluation of personal history, lifestyle habits, comorbidities and breastfeeding applied specific questionnaire.

Peripheral blood samples were collected after 12 hours of fasting for lipid profile analysis including serum total cholesterol (TC) and its fractions, LDLc, HDLc, very low density lipoprotein (VLDL-c) and triglycerides (TG) and stress oxidative analysis by measuring levels of malondialdehyde concentration (MDA). Serum concentrations of lipid fractions were performed by colorimetric enzyme method. The serum MDA concentration was performed according to the method of Khon & Liversedg [12], considering as normal limits serum 0-440 ng/dL.

Statistical analysis

The data were presented as mean ± standard deviation. The Kolmogorov-Smirnov test was performed to verify the normality of the data. Groups of children with obesity and normal weight were compared by applying the t test for independent samples. The Fisher exact test was used to check the frequency of altered biochemical markers in groups considering gender, age and BMI. The Pearson correlation coefficient was used to correlate variables related to the lipid profile, MDA and age. It is also applied multivariate principal component analysis compared the variables TC, HDLc, LDLc, VLDLc and MDA, in order to determine the association of factors between those variables. To verify the effect of other dichotomous variables (presence or absence of a sedentary lifestyle, breastfeeding, CVD history and gender) applied the t test. Significance level was assumed for p<0.05.


Group 1 consisted of 35 children with a mean age of 8±1.5 years, 40% of female, with an average BMI of 24.3±3.1 kg/m² and 21 (60%) male with BMI 25.6±2.5 kg/m&su. The group 2 included 31 normal weight children with mean age of 7±1.4 years, predominantly male (61%), BMI 16.5±1.4 kg/m². Indeed for group 2, females (39%) had BMI 16.6±2.3 kg/m².

It was observed that the group with obesity had higher TG levels (108.8±44.3 mg/dL) and VLDL-c (21.7±8.9 mg/dL) compared to normal weight group (81.5±49, 5 mg/dl, 16.3±9.9 mg/dL, respectively, p=0.02 for both). However, both groups showed similar levels of LDLc, HDLc and CT (Table 1). Also, there was a higher frequency of individuals with altered levels of VLDL-c (51.4%) and TG (51.4%) in the obese group compared to normal weight (22.6%; p=0.02 for both variables).