High Blood Pressure and Changes in the Body Mass Index Category Among Japanese Children: A Follow-Up Study Using the Updated American Academy of Pediatrics Guidelines.

Background High blood pressure (HBP) has become a public health issue worldwide. The relationship between high BP and changes in the body mass index (BMI) category in Japanese pubertal children has not yet been examined. To resolve this issue, we examined existing data with a focus on the primordial prevention of high BP signs, including elevated BP, among pubertal children aged 12 and 15 years. Methods Height, body weight, and BP data were examined from health checkups of 18,247 children conducted between 1993 and 2000 in the Karatsu Study, which was a cohort of pediatric lifestyle-related disease prevention medical health checkups in Japan. BP and BMI were assessed using the updated American Academy of Pediatrics (AAP) guidelines and Endocrine Society's clinical practice guidelines definitions, respectively. Results Follow-up data were obtained from 7,090 subjects (50.5% boys). Stage 2 hypertension (HTN) was detected in 3% and 2.7% of boys and girls aged 12 years, respectively, and in 2.7% and 1% of boys and girls aged 15 years, respectively. Among children aged 15 years, 1.4% were newly classified with stage 2 hypertension, and 15.6% exhibited improvements to a normal BP. A binomial logistic regression analysis of high BP and BMI category changes revealed odds ratios (OR) in the group with a deteriorated BMI category of 1.51 (95% confidence interval (CI), 1.17-1.94), 2.30 (95%CI, 1.66-3.17), and 6.83 (95%CI, 4.14-11.29) for elevated BP, stage 1 hypertension, and stage 2 hypertension, respectively. Conclusion High BP in puberty positively correlated with BMI category changes. Considering the presence of the tracking phenomenon in hypertension, BP monitoring is an essential part of the early strategy for the prevention of lifestyle-related diseases in childhood, and improvements in BP control are crucial in early life.