The prevalence of hypertension and other lifestyle diseases in children and adolescents has become a growing concern in the past decade.
In India, states like Kerala, with a higher human development index than most other parts of the country, are facing a higher burden of non-communicable diseases like diabetes, hypertension etc.
The present study was conducted as part of the project for assessing the non-communicable disease risk factors in adolescent age higher secondary school children in Thiruvananthapuram district, in Kerala and was aimed at assessing the prevalence of hypertension and its associated factors among the students who are transitioning into adulthood. Higher secondary classes were selected because most of them belonged to middle to late adolescence, the age of initiation of various risk factors such as tobacco use, unhealthy diet patterns etc. and an apt age for intervention before they reach adulthood.
This Cross-sectional study was conducted among class eleven students in Government and Government-aided Higher Secondary Schools in Thiruvananthapuram district. Higher secondary school students (class eleven) between the ages of 15-18 years in the selected Government/ Government-aided schools, were recruited for the study after obtaining their parents’ consent and assent of the students. Children who were severely sick or absent on the day of data collection were excluded from the study.
Participants were selected based on a multistage cluster sampling process from five randomly selected schools each from all three educational sub-divisions in the district. From the available science, commerce and humanities divisions of Class eleven in each school, one division in each available academic stream was randomly selected and students belonging to selected class were enlisted for the study. From the list available from the educational department, five higher secondary schools were selected from each sub educational district. Thus 15 schools were selected from mixed schools, girl’s only schools, boy’s only schools, special schools, and schools in marginalized areas in each sub-district. One class division each was randomly selected from the available class eleven Science, Commerce, and Humanities academic streams in the schools. A minimum sample size of 1700 was calculated based on the least prevalence of non-communicable disease risk factors (physical activity, overweight, hypertension, tobacco use) among adolescents which would accommodate for all the other risk factors, and using an expected prevalence of 7.98 percent of hypertension which was obtained from a school based pilot study conducted by the researchers in Thiruvananthapuram district itself.
The lifestyle assessment of the students with regard to non-Communicable Diseases was done using a pre-tested, self-administered questionnaire in the local language, which recorded the socio-demographic details along with diet, physical activity patterns, and habits. Physical examination findings of Height, Blood Pressure, and additional findings also were recorded.
Blood Pressure (BP) was measured in the right arm by using standard measurement practices. BP was measured after the student rests for at least 5 minutes in a sitting position, by a medical officer using standardized, professionally precalibrated mercury sphygmomanometer using auscultatory method, using an appropriately-sized cuff selected based on expert recommendations. Two separate readings were taken for each student at a 10-minute interval and the average of the two systolic BPs was calculated as the Systolic BP, and the average of the two Diastolic BPs were taken as the Diastolic BP. The American Academy of Pediatrics (AAP) standard guideline for measurement of blood pressure was used for the BP measurement.
Body weight was measured to a nearest of 0.01 kg using a precalibrated digital weighing scale. Height was recorded in centimeters using a portable stadiometer. Weight and height were converted to metric measurements in order to determine the Body Mass Index (BMI) and classified based on the Indian Academy of Pediatrics (IAP), Standardized BMI chart for Indian children, and the Extended International Obesity Task Force (IOTF) measurement.
A ten-item Perceived Stress Scale, developed by Cohen et al, was used to measure the stress levels.
The average systolic and diastolic blood pressures were calculated. Factors associated with hypertension were assessed using chi-square analyses, and multivariate logistic regression in Statistical Package for the Social Sciences (SPSS) version 25.
The study was conducted after obtaining clearance from the Institutional Ethics Committee. (Clearance no-03/CDC/2018 dated 19/5/2018). Assent of the students and
The study was conducted among 1852 higher secondary students. About 65.8% were girls and half of them were from science stream. About 52.9% belonged to APL (Above poverty line category, while 47.1% belonged to BPL (Below Poverty line) category. Around 76% were from rural areas while 24 % from urban areas.
We found that 457(24.68%; CI: 22.7%-26.6%) and 153(8.31%; CI: 7%-9.5%) of the students had average blood pressure more than the latest AHA/AAP guidelines for Grade 1 (systolic BP 130 -139 mm Hg; diastolic BP 80-89 mm Hg) and Grade II (systolic BP 140 mm Hg or more, or diastolic BP 90 mm Hg or more) hypertension respectively.
Bivariate analyses revealed that levels of hypertension (both Grade I and Grade II combined) were significantly higher in boys (p 0.001), overweight students (p 0.001) those of a higher socio-economic status (p 0.002), children with lower levels of fruit intake (p 0.002), lower daily physical activity (p 0.048) higher screen time (p 0.037), and those who were engaged in drug (p 0.02) and smokeless tobacco abuse (p 0.005). We did not find any significant association between blood pressure levels and the place of residence (rural/urban) of the students, junk food consumption, or perceived stress levels [
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Gender |
Male |
394 |
240 (37.9%) |
634 |
0.001 |
|
Female |
846 |
370 (30.4%) |
1216 |
||
|
Socio-economic status |
BPL |
603 |
265 (30.53%) |
868 |
0.002 |
|
APL |
629 |
345 (35.42%) |
974 |
||
|
Residence location |
Rural |
942 |
463 (32.95%) |
1405 |
0.908 |
|
Urban |
295 |
147 (33.26%) |
442 |
||
|
Consumption of deep fried snacks |
Less than three days a week |
552 |
300 (35.21%) |
852 |
0.058 |
|
Three or more days a week |
676 |
303 (30.95%) |
979 |
||
|
Consumption of sugar-sweetened beverages |
Less than three days a week |
1092 |
523 (32.38%) |
1615 |
0.068 |
|
Three or more days a week |
136 |
86 (38.74%) |
222 |
||
|
Fruit consumption |
Less than a day per week |
138 |
89 (39.21%) |
227 |
0.002 |
|
At least one day per week |
1092 |
518 (32.17%) |
1610 |
||
|
Recreational Screen time |
Within 2 hours/ day |
835 |
381 (31.33%) |
1216 |
0.037 |
|
More than 2 hours/ day |
380 |
216 (36.24%) |
596 |
||
|
Daily Physical Activity |
Less than half an hour a day |
189 |
115 (37.83%) |
304 |
0.048 |
|
Half an hour or more a day |
1044 |
491 (31.99%) |
1535 |
||
|
Drug abuse |
Never user |
1212 |
589 (32.70%) |
1801 |
0.02 |
|
Current/Past user |
17 |
18 (51.43%) |
35 |
||
|
Smokeless tobacco |
Never/Past user |
1227 |
598 (32.77%) |
1825 |
0.005 |
|
Current user |
4 |
5 (55.56%) |
9 |
||
|
Perceived Stress levels |
Low-Moderate |
1150 |
559 (32.71%) |
1709 |
0.148 |
|
High |
74 |
45 (37.81%) |
119 |
||
|
Body Mass Index |
Not overweight |
1064 |
400 (27.32%) |
1464 |
0.001 |
|
Overweight |
170 |
210 (55.26%) |
380 |
Multivariate logistic Regression revealed higher odds of Hypertension in boys (adjusted Odds Ratio- aOR 1.62, Confidence Interval: 1.3-2.0), overweight students (aOR 3.45, CI: 2.71-4.39), students with lower fruit intake (aOR 1.44, CI 1.06-1.95), lower daily physical activity (aOR 1.42, CI 1.08-1.86), and those who were currently using smokeless tobacco products (aOR 3.71, CI: 1.1-12.5) [
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Lower limit |
Upper Limit |
|||
|
Male |
1.619 |
1.301 |
2.016 |
0.001 |
|
Fruit consumption less than once a week |
1.436 |
1.057 |
1.951 |
0.021 |
|
Less than half an hour of daily physical activity |
1.419 |
1.08 |
1.864 |
0.012 |
|
Overweight |
3.445 |
2.705 |
4.388 |
0.001 |
|
Current use of smokeless tobacco |
3.709 |
1.101 |
12.496 |
0.034 |
The study was conducted in the background of the rising NCD burden and risk factors in the state and aimed at assessing the situation among adolescents about to enter adulthood. The present study was conceived from the findings related to hypertension from a study conducted by the researchers in a single school in the district.
The studies on hypertension among children and adolescents in India were mostly urban or rural school-based studies and involved pre-adolescent and early adolescent age groups. Studies among middle to late adolescents or those in early stages of youth, as well as those in district-wide samples have been very rare. The prevalence of hypertension or elevated blood pressure from these studies vary from around 5% in Delhi to around 21% in both Chennai and Ahmadabad.
The present study found higher prevalence of hypertension among males. Studies in Delhi, had found higher levels of diastolic hypertension in adolescent boys compared to girls, and higher levels of systolic hypertension in girls.
The levels of hypertension that emerges from the study are alarming, as it has been shown that NCD risk factors in children and adolescents like elevated blood pressure and obesity tend to track into adulthood as well and will add to the NCD burden of the state in the near future as these students enter adulthood.
Elevated BP in childhood has also been found to be associated with early markers of cardiovascular abnormalities such as left ventricular hypertrophy and atherosclerosis.
The present study used pre-tested questionnaires in the regional language for data collection, along with standardizing measures. The study was preceded by a pilot study in the same district, based on which sampling was done, and schools in different categories from all three educational sub-districts in the district were included in the study, which adds to the generalizability of the results in the region.
This cross-sectional study, based on self-reported data from students, may be subject to recall bias. Conducted exclusively in Kerala, its findings may not be generalizable to other regions in India, where health indicators and socioeconomic conditions vary. Additionally, the design limits causal inferences.
High levels of hypertension among higher secondary school students in the district indicate that the state is looking at a significant proportion adults and young adults requiring medical care for hypertension and related complications in the near future. This warrants reinforcement of the existing NCD preventive programs in the state with the adoption of blood pressure monitoring of adolescent students for early detection of hypertension and timely interventions, in order to reduce the morbidity due to NCDs. For this, we recommend that the school health programs in the state be expanded with yearly screenings of blood pressure and other NCD risk factors and mechanisms for intervention and follow up be set up. Measures also need to be taken to improve the physical activity habits of the students, and to discourage the abuse of tobacco products among school children, along with measures to increase healthy foods like fruits in the diet.
The researchers sincerely acknowledge the support of the Directorate of Higher Secondary Education, Kerala for permission and support in conducting the study. We also thank the Heads of the institutions and teachers for aiding with the coordination of field activities at the schools.
No external funding.
None.