Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange
Abstract
Background: Increased arterial stiffness, an independent predictor of premature cardiovascular events, has been observed in white American obese children yet data are limited in ethnic minority youth, which are disproportionately affected by the cardiovascular consequences of childhood obesity. Indeed, childhood obesity in ethnic minorities may accelerate arterial stiffness, precipitating the premature development of CVD. The aims of the present study were to determine 1) if arterial stiffness is increased in overweight/obese children, 2) if, despite similar levels of body adiposity, arterial stiffness is greater in ethnic minority compared to white American children, and 3) if the presence of cardiovascular disease risk factors worsens arterial stiffness in overweight or obese children. Methods and Results: Thirty-six children were studied: 18 healthy weight (BMI: 19.5±1.9 kg/m2) and 18 overweight/obese (26.8±3.5 kg/m2). Twenty-eight of the 36 children were white American and 8 were ethnic minorities (6 American Indian, 1 Hispanic, and 1 Filipino). Arterial stiffness, as indicated by aortic pulse wave velocity (aPWV), was assessed by pulse wave analysis (applanation tonometry, SphygmoCor CPV) of the carotid and radial arteries. A secondary indicator of arterial health, aortic augmentation index (AiX), was also assessed in the radial artery via a similar technique. There were no differences (P=0.46) in aPWV between the healthy weight (7.1 ± 1.4 m/s) overweight (7.1 ± 0.8 m/s) or obese (7.3 ± 1.2 m/s) children. In addition, no difference was found in aortic AiX between healthy weight (-0.5 ± 3.5%) overweight (4.5 ± 2.9%)or obese (6.1 ± 3.3%) children. However, after stratifying the children into white American and ethnic minority groups, an adverse influence of ethnicity on arterial stiffness emerged. Indeed, in the total sample, aPWV was markedly elevated (P=0.002) in the ethnic minority children (7.7±1.1 m/s) compared with their white American peers (6.8±0.5 m/s). On the contrary, no significant difference existed in aortic AiX between AI and WA children (5.50 ± 4.01 vs. 4.82 ± 2.66, p = .886). However, because obesity was overrepresented in the 8 ethnic minorities, we matched them with a subset of 8 white American children on the basis of sex, age and BMI. Nevertheless, despite similar degrees of obesity, the ethnic minorities still demonstrated with increased (P=0.03) aPWV (7.7±1.1 versus 6.8±0.4 m/s) compared with matched white American children. Again, there were no differences in aortic AiX between the groups, however, it was on average 5% higher in the AI/ethnic minorities (6.4 ± 3.1%) than in WA children (0.9 ± 3.7%). Lastly, despite a greater burden of risk factors, there was no significant difference in aortic PWV (7.1 ± 0.9 m/s vs. 7.4 ± 1.1 m/s) or aortic AiX (5.1 ± 2.7% vs. 4.8 ± 3.2%) between the group with zero - 1 risk factor and ≥ 2 risk factors, respectively.Conclusions: The impacts of childhood obesity on arterial stiffness appear to be worse in ethnic minorities. A variety of health disparities (e.g., cultural, socioeconomic, environmental, and/or biological) may contribute to increase arterial stiffness in obese ethnic minority children placing them at risk of premature CVD
