This study evaluated the relationship of lipid profile and waist circumference as cardiovascular risk factors with overweight and obesity in Qatari children. The main findings of our study were that overweight and obese children screened by IOTF criteria had consistently more adverse cardiovascular risk factors, including increased waist circumference, hypercholesterolemia, hypertriglyceridemia, and atherogenic index, with lower levels of HDL-C than children who were not overweight or obese. In addition, overweight and obesity in children increases the odds of having cardiovascular risk factors, ie, increased waist circumference, hypercholesterolemia, and hypertriglyceridemia, with lower levels of HDL-C and atherosclerosis.
Several studies have shown that the association between obesity and cardiovascular risk begins early in life.3
Body mass index and waist circumference each measure a distinct component of obesity or body fat distribution, and waist circumference is consistently the best predictor of cardiovascular risk.24
Few studies are available on the relationship between waist circumference and cardiovascular risk factors in children.26
The results of the current study showed significant positive correlations between waist circumference and total cholesterol, triglycerides, and LDL-C, and an inverse correlation with HDL-C after adjustment for age and gender. The findings of the current study are in agreement with previous studies11
demonstrating a significant association between increased waist circumference and lipid profile. Hirschler et al demonstrated a significant association (P
< 0.01) between waist circumference and high-density lipoprotein cholesterol (r = 0.45), triglyceride (r = 0.28) levels in 84 students aged 6–13 years.28
Cowin and Emmett reported that central obesity had a significant correlation with triglycerides and HDL-C levels in preschool children that was independent of height and body mass index.29
The findings of the current study also agree with the results of the Bogalusa Heart Study, which reported an inverse association between waist circumference and HDL-C in children aged 5–9 years.30
Abnormal serum lipid levels, especially decreased HDL-C and elevated total cholesterol, triglycerides, and LDL-C, are generally recognized as independent risk factors for cardiovascular disease.31
Our study demonstrated an abnormal lipid profile with regard to elevated total cholesterol, triglycerides, LDL-C, and atherogenic index, and reduced HDL-C in overweight or obese children. Our results show that overweight and obesity in school children increases the likelihood of adverse cardiovascular risk factors, including increased waist circumference and hypercholesterolemia, hypertriglyceridemia, and low HDL-C, which is consistent with previous studies.34
Botton et al showed partial correlations between hypertriglyceridemia, hyperinsulinemia, and low plasma HDL-C levels that were related to all measures of adiposity in 452 children aged 8–17 years. In addition, they demonstrated that moderate excess weight is linked with increased cardiovascular risk, and among girls, abdominal fat distribution is correlated with cardiovascular risk factors independently of adiposity markers.34
In agreement with our findings, another study performed in Venezuela in a sample of 370 second grade students aged 7.82 ± 0.62 years found a significant positive correlation between waist circumference, body mass index, and atherogenic indices, ie, triglycerides/HDL-C, total cholesterol/HDL-C, and low-density lipoprotein cholesterol/HDL-C (P
The lipid profile results for children in the current study highlight the risks of dyslipidemia among Qatari school children and its consequences for the cardiovascular system. Long-term observations from the Bogalusa Heart Study demonstrate that obesity in childhood is a major driving force for insulin resistance syndrome. Recent studies have demonstrated that insulin resistance is implicated in the association between obesity and dyslipidemia, which contributes to an increased risk of cardiovascular disease.37
In addition, the current study shows a high prevalence of pediatric overweight, including obesity, in Qatari children (31.71% in boys and 33.78.% in girls) by IOTF criteria. The results of this study are similar to those of a recent study by Kerkadi et al, which reported a prevalence of overweight and obesity by age of 33.2%, 33.5%, and 44.7% for boys and 37.0%, 38.9% and 43.3% for girls aged 9, 10, and 11 years using IOTF references, respectively.15
Other studies among adolescents in Qatar report a high risk of overweight and obesity.14
In the United Arab Emirates, it has been reported that 21.5% of children aged 5–17 years are overweight and 13.7% are obese.38
This study indicates an apparently elevated frequency of overweight and obesity among children in the Gulf region, at rates close to that reported in the current study among children aged 6–11 years. The proportions of overweight and obesity among children in our study are similar to or higher than those reported in some industrialized countries in the past few decades.1
In summary, the present study indicates that the combination of elevated total cholesterol, triglycerides, and LDL-C, and decreased HDL-C, with waist circumference above the 90th percentile in overweight and obese children, would place them at greater risk for cardiovascular disease. These data are consistent with previous studies in different ethnic groups.41
Further studies are needed in larger sample sizes to investigate if other biomarkers could be used to define obesity and overweight among Qatari schoolchildren and the implications for early detection of increased cardiovascular risk.
The present study was limited by its small size sample of 300,000 Qatari schoolchildren. Blood pressure was not measured, which limits the associations of obesity with the metabolic syndrome as a cluster of potential risk factors for atherosclerotic cardiovascular disease and type 2 diabetes. Further pubertal stage was not determined in this cross-sectional study, which prevents measurement of lipid profile at different stages of puberty.