|Ahead of print publication
Study of blood pressure and its relationship with anthropometric variables among school children
Ilankumaran Mookkiah1, Mahendra Vikram Singh1, Saurbah Bobdey1, Anand Neelakandan2, Kiran Kumar Maramraj1
1 Integrated Headquarters Ministry of Defence (Navy), New Delhi, India
2 Station Health Organisation, Kochi, Kerala, India
|Date of Submission||12-Jul-2020|
|Date of Decision||12-Dec-2020|
|Date of Acceptance||27-Dec-2020|
|Date of Web Publication||01-Apr-2021|
Room No. 138, “A” Wing, Sena Bhawan, Integrated Headquarters Ministry of Defence (Navy), New Delhi - 110 011
Source of Support: None, Conflict of Interest: None
Introduction: Hypertension is a global public health issue. Blood pressure (BP) has been shown to track (or persist) from childhood to adulthood. Obese and overweight children have a higher prevalence of elevated BP than normal weight children. Hence, the prevention of childhood obesity is one of the cardinal strategies for the prevention of hypertension and cardiovascular risks later in life. Materials and Methods: It was a cross-sectional study conducted among school children of age 10 years and above. BP and anthropometric measurements such as height and weight were measured using standard methods for 1620 children. The data were compiled and statistical analysis was done to assess the relationship between BP and anthropometric parameters. Results: A total of 990 boys and 630 girls were examined. The mean age for boys was 14 years (range 10–18 years) and mean age of girls was 13.8 years (range 10–18 years). The mean systolic BP and diastolic BP of the study participants increased uniformly with the increase in weight, height, and body mass index (BMI). A significant positive correlation was observed between anthropometric parameters and BP. Conclusion: This study reinforces the evidence of significant correlation between BP and anthropometric parameters in school children. Enhancing awareness and institution of good lifestyle habits at an early age hold the key to the prevention of lifestyles diseases in adults. Hence, school children with increased weight and BMI are to be counseled regarding their diet and they should be encouraged to undertake regular physical activity.
Keywords: Blood pressure, body mass index, school children, weight
| Introduction|| |
Hypertension is a silent killer and is growing public health problem across the globe. It contributes to burden of heart disease, stroke, kidney disease, and premature mortality. It rarely causes symptoms in the early stages and many people go undiagnosed. The disease is more prevalent and the number of people with hypertension who are undiagnosed, untreated, and uncontrolled are higher in low- and middle-income countries as compared to high-income countries.
Although hypertension is detected and treated in adulthood, blood pressure (BP) has been shown to track (or persist) from childhood to adulthood. The present scientific literature indicates that individuals with elevated BP during their childhood have an increased risk of developing prehypertension and hypertension in adulthood. In addition, it has also been claimed that increased BP in childhood is a predictive factor for cardiovascular risks in adults.
It has been established that obese and overweight children have a higher prevalence of elevated BP than normal weight children. Hence, the prevention of childhood obesity by providing healthy guidelines should be one of the cardinal strategies for the prevention of hypertension and cardiovascular risks later in life.
Many studies among school children in India have shown positive correlation between BP and various anthropometric measurements such as height, weight, and body mass index (BMI).,, In order to explore and reassess the association between BP and anthropometric parameters and to find out the distribution of BP among school children in an urban setting, the present study was conducted in a Government school at Delhi.
| Materials and Methods|| |
The study was a cross-sectional descriptive study conducted among school children of age 10 years and above in a government co-educational school in New Delhi. One of the government schools in New Delhi was selected randomly to conduct the study. No sampling technique was adopted and all children above 10 years of age studying in the selected school were included the study. However, children who gave a history of hypertension or drug intake which would alter the BP level were excluded from the study.
Three teams of paramedical personnel (one male and female each) were trained for taking necessary measurements and taking down personal particulars and history of taking any medication regularly. Further, each team was ear-marked for taking measurements of one anthropometric parameter such as first team measured height, second team measured weight, and third team BP. All the teams were trained by the principal author and equipment used for taking measurements including weighing machine and sphygmomanometer were calibrated before and during the study. The data were collected in November 18.
BP was measured using a mercury sphygmomanometer and auscultatory method. The subject was seated comfortably on a chair for 5 min with arm relaxed and forearm supported on a table placed in front of the subject, with cubital fossa at the level of the heart (fourth intercostal space). The cuff of the appropriate size was applied, so as to encircle the right arm and lower border more than 2.5 cm from the cubital fossa. Two readings of the BP were taken at an interval of about 3 min and the mean of the two values was taken as the BP, both for systolic BP (SBP) as well as diastolic BP (DBP). This entire procedure was in accordance with World Health Organization (WHO) recommendations. Height and weight were recorded in accordance with the recommended measurement protocols laid down by the WHO (TRS 854).
All the collected data were entered into excel spread sheet and these data were cross-checked with the physical data for any discrepancy. The data were analyzed using an electronic statistical software (IBM SPSS for windows, version 20.0. IBM Corp., Armonk, NY, USA).
| Results|| |
A total of 990 boys and 630 girls were examined. The mean age for boys was 14 years (range 10–18 years) and mean age of girls was 13.8 years (range 10–18 years). The mean SBP and DBP of the both boys and girls were found to be higher in older age groups. The mean SBP and DBP among boys ranged from 106.56 mm Hg at 11 years age to 123.18 mm Hg at 18 years and 73.68 mm Hg at 11 years to 77.78 mm Hg at 18 years, respectively. In girls, the mean SBP and DBP ranged from 110.13 mm Hg at 10 years to 115.65 mm Hg at 18 years and 74.29 mm Hg at 10 years to 82.15 mm Hg at 18 years, respectively.
The percentile values of SBP and DBP for different ages for the 5th, 25th, 75th, and 95th percentiles are presented in [Table 1] for boys and [Table 2] for girls, respectively. In addition, it was observed that 6.02% (64) boys had SBP more than 130 mm of Hg and 2.71% (27) had DBP >90 mm of Hg. In girls, 6.66% (42) were found to have SBP more than 130 mm of Hg and 6.50% (41) were found to have DBP more than 90 mm of Hg.
|Table 1: Distribution of systolic and diastolic blood pressure according to age (boys) (n=990)|
Click here to view
|Table 2: Distribution of systolic and diastolic blood pressure according to age (girls) (n=630)|
Click here to view
Mean systolic and DBP as per anthropometric parameters (weight, height, and BMI) are tabulated in [Table 3] and [Table 4] for boys and girls, respectively. The mean SBP and DBP of the study participants increased uniformly with the increase in weight, height, and BMI. A significant positive correlation was observed between the anthropometric parameters and the BP [Table 3] and [Table 4].
|Table 3: Distribution of systolic and diastolic blood pressure in relation to different anthropometric variables (boys) (n=990)|
Click here to view
|Table 4: Distribution of systolic and diastolic blood pressure in relation to different anthropometric variables (girls) (n=630)|
Click here to view
| Discussion|| |
In the present study, the mean SBP and DBP for each age group are higher than average SBP and DBP of rural school children, both boys and girls of Maharashtra. The difference in certain categories is more than 10 mmHg. Similarly, the mean SBP and DBP for each age group among boys in the present study are higher than the school boys of Burdwan Municipal Area, West Bengal. However, the mean SBP and DBP of boys and girls in each age group are similar and lesser than school boys and girls of Aligarh. This difference in BP between rural and urban school children could be due to the higher prevalence of elevated BP in urban population as compared to rural population.
In the present study, the mean SBP and DBP have shown an increase as the age increased, both for boys and girls. There was a positive correlation between height and SBP and DBP for both for boys (Correlation Co-efficient 0.406 for SBP and 0.160 for DBP) and girls (Correlation Co-efficient 0.163 for SBP and 0.166 for DBP). Similar results were shown in various studies conducted among school children of different age groups in rural Maharashtra (age 6–15 years), Burdwan Municipal Area West Bengal (age 13–18 years), urban area in Tamil Nadu (age 10–15 years), Aligarh (age 12–16 years), and urban slums of Kolkata (age 10–19 years).
In the present study, there was a positive correlation between weight and SBP and DBP for both boys (r = 0.427, P < 0.05 for SBP and r = 0.168, P < 0.05 for DBP) and girls (r = 0.228, P < 0.05 for SBP and (r = 0.253, P < 0.05 for DBP). Similar positive correlation has been observed between BMI and SBP and DBP for both boys (r = 0.335, P < 0.05 for SBP and (r = 0.136, P < 0.05 for DBP) and girls (r = 0.186, P < 0.05 for SBP and (r = 0.220, P < 0.05 for DBP).
In children, SBP and/or DBP above 95th percentile for age, sex, and height are considered as hypertension. The 1999–2000 National Health and Nutrition Examination Survey in the US among children has shown that the 95th percentile SBP and DBP for boys of age from 10 to 17 years ranged from 123 to 140 mm Hg and from 82 to 89 mm Hg, respectively. For girls of the same age group, the 95th percentile SBP and DBP ranged from 124 to 140 mm Hg and 84–92 mm Hg, respectively. In the present study, 95th percentile SBP and DBP among boys were higher that the US study, whereas for girls 95th percentile SBP and DBP were lower than the US study.
A large number of studies conducted in India among school children of various age groups with sample size ranging from 129 to 3264 have shown similar results of positive correlation between weight and BMI and SBP and DBP.,,,, A study of 522 children of age 6–15 years in rural Maharashtra has shown a fair degree of linear relationship between BMI and BP (SBP r = 0.43, P < 0.05, and DBP r = 0.39, P < 0.05). A study in urban schools of Tamil Nadu with large sample size of 3264 children of age 10–15 years revealed progressive increase in SBP and DBP with increase in weight (SBP r = 0.44, P < 0.05, and DBP r = 0.42, P < 0.05) and BMI (SBP r = 0.38, P < 0.05, and DBP r = 0.38, P < 0.05). The positive correlation between BP and BMI is seen among urban slum children also. A study among 129 school children of age 10–19 years from urban slums of Kolkata has shown a positive correlation between BMI and SBP (r = 0.30, P < 0.05) and DBP (r = 0.26, P < 0.05). A few studies in South America and Africa have also shown similar results. In a study of 4609 school children of age 6–11 years in Brazil SBP and DBP were positively and significantly correlated with BMI (SBP r = 0.45, P < 0.05, and DBP r = 0.34, P < 0.05).
The burden of cardiovascular diseases has been increasing steadily in the World. Primary hypertension is one of the main risk factors for acute cardiovascular catastrophe such as coronary heart disease and cerebrovascular accident. Furthermore, hypertension affects various organs including eyes and kidneys leading to irreparable damages. The causes of hypertension are multifactorial and the risk factors include age, sex, hereditary, obesity, and lack of exercise. This study has reiterated the positive correlation between BP and height, weight, and BMI in school children. It is therefore imperative that children at schools be educated about obesity and its prevention through lifestyle measures such as consumption of healthy diet, knowledge about dietary guidelines and importance of regular physical activity. By providing adequate knowledge and awareness, the young minds can be molded to adopt healthy lifestyle which would go a long way in prevention of life style diseases in adulthood.
| Conclusion|| |
It is strongly recommended that school children are to be examined once a year as part of school medical examination to assess their weight and BMI. Children with high weight and BMI are to be counseled regarding their diet and they should be encouraged to undertake regular physical activity. In addition, schools should provide adequate time and facility for children to undertake physical activity including playing games of their choice. These efforts would help in preventing/postponing onset of lifestyle diseases, particularly hypertension in adults.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
World Health Organisation. A Global Brief on Hypertension. Geneva, Switzerland: WHO/DCO/WHD/2013.2; 2013.
Magnussen CG, Smith KJ. Pediatric blood pressure and adult preclinical markers of cardiovascular disease. Clin Med Insights Blood Disord 2016;9:1-8.
Theodore RF, Broadbent J, Nagin D, Ambler A, Hogan S, Ramrakha S, et al.
Childhood to early-midlife systolic blood pressure trajectories: Early-life predictors, effect modifiers, and adult cardiovascular outcomes. Hypertension 2015;66:1108-15.
Rosaneli CF, Baena CP, Auler F, Nakashima AT, Netto-Oliveira ER, Oliveira AB, et al
. Elevated blood pressure and obesity in childhood: A cross-sectional evaluation of 4,609 schoolchildren. Arq Bras Cardiol 2014;103:238-44.
Oh JH, Hong YM. Blood pressure trajectories from childhood to adolescence in pediatric hypertension. Korean Circ J 2019;49:223-37.
Reddy D, Kushwaha AS, Kotwal A, Basannar DR, Mahen A. Study of blood pressure profile of school children 6-15 years in a rural setting of Maharashtra. Med J Armed Forces India 2012;68:222-5.
Baradol RV, Purushotham DR. A study of blood pressure in rural and urban school children. Int J Contemp Pediatr 2018;5:1261-6.
Nag K, Karmakar N, Saha I, Dasgupta S, Mukhopadhyay BP, Islam Mondal MR. An epidemiological study of blood pressure and its relation with anthropometric measurements among schoolboys of Burdwan municipal area, West Bengal. Indian J Community Med 2018;43:157-60.
] [Full text]
Durrani AM, Waseem F. Blood pressure distribution and its relation to anthropometric measurements among school children in Aligarh. Indian J Public Health 2011;55:121-4.
] [Full text]
Ramalingam S, Chacko T. Blood pressure distribution and its association with anthropometric measurements among Asian Indian adolescents in an urban area of Tamil Nadu. Int J Med Sci Public Health 2014:3:1100-4.
Maiti M, Bandyopadhyay L. Variation in blood pressure among adolescent schoolchildren in an urban slum of Kolkata, West Bengal. Postgrad Med J 2017;93:648-52.
US Department of Human and Health Services. A Pocket Guide to Blood Pressure Measurement in Children. From the Fourth Report on the Diagnosis, Evaluation and Treatment of High Blood Pressure in Children and Adolescents. NIH Publication 07-5268, May 2007.
[Table 1], [Table 2], [Table 3], [Table 4]