Children, obesity, and high blood pressure: Asian populations at high risk.

C hildhood obesity is increasingly being recognized as a major public health problem worldwide. Elevated blood pressure (BP) in youth has been associated with increased atherosclerosis, and tracks into adulthood. 1 Hypertension is a leading contributor to the global burden of cardiovascular morbidity and mortality. 2 In this issue of AJH, Ke and colleagues present their important work which highlights the enhanced susceptibility of South East (SE) Asian-origin children in Sydney to obesity and associated hypertension. 3 In a cross-sectional analysis of 216 children aged 8–9 years of SE Asian and 381 of Australian origin from 75 inner city schools in Sydney, Ke et al. observed that increased obesity indices (body mass index (BMI), waist circumference, skin fold thickness) were associated with elevated levels of BP. 3 These relationships were more pronounced in SE Asians compared to Australians, and persisted even with lower (Asian-specific) BMI thresholds for defining overweight or obesity in the former. In addition, longitudinal follow-up of about half of this cohort revealed that an increase in adiposity over 3 years was associated with rise in systolic BP in SE Asian but not in Australian children. Moreover, a significant interaction was also detected between baseline BMI and change in BMI over 3 years on systolic BP in SE Asian children, which suggested that the rise in BP due to weight gain is exaggerated in thinner SE Asian youth. Our previous report based on the analysis of large population based surveys demonstrated higher BMI-adjusted BP in native South Asian children in Pakistan compared to native white counterparts in the United States. 4 Further, adi-posity during childhood has been associated with impaired fasting glucose or diabetes in young adulthood. 5 The findings by Ke and colleagues add valuable knowledge to the existing evidence on deleterious impact of excessive weight gain on BP levels of children of Asian origin. A number of limitations of this study need to be recognized, including the small sample size, low overall recruitment rate (40%), high proportion of drop-outs (54%) and with characteristics that can potentially influence BP levels (e.g., more obese, less physically activity), and lack of data on pubertal staging. However, the number of children enrolled in the study was adequate for detection of significant interactions between ethnicity and obesity indices on BP. These interactions were consistent in both cross-sectional and prospective components of the study, and were present regardless of whether the key …