The development of adult HTN may start early in life (
8). Persistent HTN during infancy and early childhood is the primary cause of cardiovascular events, chronic kidney disease, and stroke in adulthood. Accordingly, early detection of HTN and its risk factors in different communities seems necessary to prevent future HTN-related complications and morbidity (
4,
5).
The present study’s findings indicated that the mean systolic and diastolic BP increased in the children with increasing age, height, weight, and BMI in both genders, showing the effect of age, height, weight, and BMI on BP measurement in both genders. Moreover, HTN and pre-HTN were documented in 8.4 and 7.8% of our children, reflecting the need for more attention to this health problem. Similarly, HTN and pre-HTN were detected in 5.9 and 12.3% of children in Sharma et al.'s study, which is considered an alarming condition (
8).
The prevalence of pre-HTN and HTN was 31.4 and 2.1% in Koebnick et al.'s study, indicating an average 7% of young children with HTN (
9).
In a cohort of 199513 children, including 3 - 5 (24.3%), 6 - 11 (34.5%), and 12 - 17 (41.2%) years old children, about 12.7 and 5.4% had pre-HTN and HTN, respectively, with a positive correlation with age and BMI (
10).
About 8.4 and 7.5% of our children with HTN and pre-HTN were males and females, respectively. In total, 5.8 and 6.3% of our children had systolic or diastolic HTN and pre-HTN, respectively.
In another study, 13.6% of boys and 5.7% of girls aged 8 - 17 years were classified as pre-hypertensive, in addition to 2.6% of boys and 3.4% of girls with established HTN (
8). However, the prevalence of HTN and pre-HTN was nearly equal in both genders in our study.
Similarly, systolic and diastolic HTN and pre-HTN had nearly equal frequency in our population. Systolic and diastolic HTN were detected in 0.8 and 0.4% of patients in the update of Taskforce Report on BP, with no significant difference between girls and boys regarding the prevalence of systolic HTN (2.7%), but with a higher number of girls with diastolic HTN. In addition, systolic BP was significantly higher in boys than girls, whereas DBP was significantly higher in girls than boys (
11).
The prevalence of obesity has been increased secondary to dietary habits, increased salt intake, and decreased physical activity. A strong correlation has been recognized between increased body weight and HTN, and obesity has been considered a significant risk factor of HTN, especially systolic BP (11 - 30%) (
6,
12,
13). Therefore, prevention and treatment of obesity might decrease the incidence of HTN.
About 27.9 and 11.2% of our obese children had HTN and pre-HTN, respectively, composing a relatively high number of children with increased BP and emphasizing increased body weight as a major predictor of future HTN.
The prevalence of HTN and pre-HTN was 22.0 and 13.3% in Ramos and Barros's study, with a higher incidence in males (25.4 vs. 18.8%). They documented HTN in 14.7, 24.2, and 42.3% of normal, overweight, and obese female children and 20.4, 35.5, and 41.3% of their male counterparts, respectively (
14).
Many children with normal BMI had high BP values in Rahman et al.'s study (
6). However, HTN was more severe among obese children with BMI >30. Of them, 37.5% had pre-HTN, and 12.5% had HTN. In their report, age, female gender, and BMI > 25 were independent risk factors of HTN and pre-HTN.
The overall prevalence of systolic or diastolic HTN was 4.2, 5.4, and 7.7% in Kelishadi et al.'s study (
15), without a significant difference between genders, similar to our study. In addition, both systolic and diastolic HTN occurred more commonly in overweight and tall children.
5.1. Conclusion
Due to the high incidence of HTN, regular monitoring of BP is recommended in asymptomatic healthy-appearing children to prevent its further risks in adulthood. Further studies with larger populations are suggested to estimate the true incidence of HTN in different communities.