Background: Studies have shown low levels of high-density lipoprotein cholesterol (HDL-C) in indigenous children versus urban children from Argentina. We hypothesized that indigenous children living at high altitudes might have lower HDL-C levels compared with U.S. children, probably due to ambient hypoxia, lifestyle conditions, or ethnicity. This study was designed (1) to compare HDL-C levels in Argentinean indigenous children with those reported in the 2011-2012 National Health and Nutrition Examination Survey (NHANES) for U.S. children and (2) to determine the association between HDL-C and adiposity in both groups.
Subjects and methods: A cross-sectional study of 1,232 (631 females) Argentinean indigenous schoolchildren (4-14 years old) from San Antonio de los Cobres (SAC) was performed between November 2011 and November 2014. Anthropometric measures were performed in the whole group and compared with those of 2,151 U.S. children (1,034 females). However, HDL-C concentrations were measured in 905 SAC children and compared with those of 1,451 U.S. children. Analyses were done incorporating sampling weights for age in both samples to obtain unbiased estimates. In the case of NHANES the weights provided by each individual in the 2011-2012 NHANES demographic file were used, whereas in the SAC sample the weights were obtained using the census data provided by the 2010 National Statistics and Censuses Institute of Argentina.
Results: The prevalence of overweight/obesity was significantly lower in SAC (135/1,232; 11%) than in the United States (759/2,151; 35%). However, the prevalence of low levels of HDL-C was significantly higher in SAC (298/905; 33%) than in the United States (142/1,451; 10%). The prevalence of low levels of HDL-C increased significantly in both groups as body mass index categories increased. Multiple logistic regression analysis showed that SAC children had nine and a half times the odds of having low levels of HDL-C compared with U.S. children, adjusted for confounding variables (odds ratio = 9.55; 95% confidence interval, 7.18-12.71).
Conclusions: This study shows a high prevalence of low levels of HDL-C in indigenous Argentinean children 4-14 years of age living at high altitudes compared with U.S. children.