Background: Pediatric hypertension is a field of increasing interest and importance. Early identification of children at risk for hypertension is important in its control to prevent the serious long-term complications associated with the condition. The purpose of this study was to determine the prevalence of hypertension and risk factors among school going children in the district of Shubra in Greater Cairo, Egypt. Materials and Methods: School going children aged between 6 to 13 years were selected by a purposive sampling method and blood pressure measurements were taken by a mercury sphygmomanometer as per recommendation of the American Heart Association. Hypertension in children and adolescents continues to be defined as systolic BP and/or diastolic BP that is, on repeated measurement, greater than or equal to the 95th percentile. Results: Total prevalence of hypertension in our study was 15.4%. Hypertension in males was 18.8% and 12.5% in females. Prevalence of obesity in hypertensive children was 20.9% against normotensive 14.4% (P<0.05). Prevalence of hypertension in children with a family history of hypertension was 68.78% and 4.22% in children without a family history of hypertension (P=0.01). Prevalence of obesity in family members was 54.15% in hypertensive and 28% in normotensive (P<0.05). Conclusion: Prevalence of hypertension was 15.4% in the study subjects. We identified obesity and a family history of hypertension to be significantly associated with childhood hypertension.
Keywords: Children; Egypt; Hypertension; Obesity; Prehypertension; Risk Factors
The importance of measuring blood pressure (BP) in childhood and adolescence has been widely recognized [1].Elevated BP in children may be an early sign of essential (or primary) hypertension and childhood BP levels are predictive of adult BP levels [2]. Hypertension and prehypertension have been increasing among children and adolescents since the 1990s [3,4]. Hospitalization rates for children and adolescents with a diagnosis of hypertension have doubled from 1997 to 2006[5]. Among children and adolescents with hypertension, as many as one in three has target organ damage, especially left ventricular hypertrophy [6,7]. Accumulating evidence supports the theory that elevated blood pressure levels in adolescence act as a precursor of elevated blood pressure in adulthood, making it important to identify elevated blood pressure in childhood [8]. An analysis of the National Childhood Blood Pressure prehypertension developed elevated blood pressure within 2 years [9]. In 2004, the National High Blood Pressure Education Program (NHBPEP) Working Group on Children and Adolescents recommended that health-care providers measure blood pressure in children over three years of age when evaluated in a medical setting[10]. The Bright Futures guidelines developed by the American Academy of Pediatrics (AAP) at the request of the Health Resources and Services Administration (HRSA) recommend that children and adolescents between ages three and seventeen years receive blood pressure screening during their annual preventive care visit [11,12]. The National Quality Forum (NQF) has endorsed blood pressure screening as a performance measure. The NQF recommends that there be documented in the medical record as to whether the result is abnormal or normal for children during the year they reach age thirteen and during the year they reach age eighteen [13]. This study was conducted to observe the prevalence
Cairo, Egypt.
This study was a cross-sectional study carried out from September 2010 to March 2011, in a non-fee paying primary and preparatory school in the district of Shubra in Greater Cairo. It was performed on 1,335 students aged between six and thirteen years. There were 600 boys and 735 girls. The students were almost of the same socioeconomic status.
Written informed consent was taken after the study was explained to the children and their parents. The study was approved by the Ethics Committee of Al-Zahraa hospital.
Questionnaires sent to parents inquired about the child’s age, gender, address, and health conditions, both previous and current. The questionnaire also asked whether there was a medical diagnosis of hypertension among blood-related family members and which family members exactly were affected. The child was classified as having a positive family history only if the disease was present in a first-degree relative. Measurements taken for each student were weight, height, and blood pressure. Weight was measured (to the nearest 0.5 kg) with the subject standing motionless on the weighing scale with feet 15 cm apart, and weight equally distributed on each leg. Height was measured (to the nearest 0.5 cm) with the subject standing in an erect position against a vertical scale of portable stadiometer and with the head positioned so that the top of the external auditory meatus was on a level with the inferior margin of the bony orbit[14].
Blood pressure (BP) measurements were taken using a mercury sphygmomanometer as per the recommendations of the NHBPEP [10]. The measurements were taken in a quiet room in the sitting posture with the arm resting on the table.
Efforts were made to eliminate the factors, which may affect the blood pressure, e.g., anxiety, crying, exercise, etc. The average of three consecutive readings was taken as the blood pressure of the child. Children with hypertension were told to come back after a week to obtain a second reading to confirm hypertension. In 2004, the NHBPEP[10] defined hypertension in children and adolescents as systolic BP and/or diastolic BP that is at or above the 95th percentile for age, height and gender. Children with blood pressure between the 90th and 95th percentile are considered “prehypertensive” [15]. Body mass index (BMI), the body weight in kilograms divided by the square of height in meters, was used as the measure of obesity in this study. The International Obesity Task Force (IOTF) classification was utilized for the estimation of overweight and obese subjects.
Obesity in children was defined as children with a BMI value above the 95th percentile for a specific age and sex [16]. Data was analyzed using SPSS (Statistical Package for Social Science) version 17.
A total of 1,335 children were enrolled in the present study. The ages ranged from 6 to 13 years old with a mean age of 10.47± 2.27 years. The gender distribution was 735 females (55.06%) and 600 males (44.94%). From the sample, 925 children had normal blood pressure (69.3%), 205 were prehypertensive (15.4%), and 205 were hypertensive (15.4%) (Table 1). There was a statistically significant increase in both systolic and diastolic blood pressure with increasing age (Table 2). The prevalence of prehypertension among female children (16%) was slightly higher than male children (14.5%). However, the prevalence of hypertension in male children (18.8%) was higher than female children (12.5%) (Table 3). (Table 4) shows that the prevalence of normal systolic BP in female and male children was 58.2% and 41.7%, respectively. The prevalence of systolic prehypertension in male children and female children was 61.7% and 38.2%, respectively. There was a statistically significant difference between the prevalence of systolic hypertension in male (56.6%) and female (43.3%) children. Also, the prevalence of normal diastolic BP in female children (56.63%) was higher than male children (43.37%). The prevalence of diastolic prehypertension in female children (54.50%) was higher than in male children (45.50%). There was a statistically insignificant difference between the prevalence of diastolic hypertension in male children (53.18%) and female children (46.82%). A positive family history of hypertension was reported for 141 (68.78%) of the hypertensive children, and 39 (4.22%) of the normotensive children (Table 5).
The prevalence of positive family history of obesity in the hypertensive group was 54.15% and 28% in the normotensive group. The normotensive group had a family history of obesity. 3.4% of hypertensive children belong to consanguineous marriage and 3.6% of normotensive children belong to consanguineous marriage (Table 6). (Table 7) shows that the increase in BMI percentiles was associated with a statistical significant increase in BP percentiles.
Prehypertension
No. % No.
Group I (6- 7.9 y) 114 12.00 69 Group II (8- 9.9 y) 293 30.74 27 Group III (10- 13 y) 544 57.26 115
Normal No. % No. Male 413 43.37 96 Female 538 56.63 115 Total 951 100% 211
% No. % 32.70 24 13.87 97.306 0.001 12.80 83 47.98 54.50 66 38.15
Hypertension % No. % 45.50 92 53.18 5.719 0.057 54.50 81 46.82 100% 173 100%
intensified effect of BMI on BP levels may relate to an elevated activity of the sympathetic nervous system [30].A previous study observed that there was a positive correlation between blood pressure and obesity and reported that among all demographic and clinical factors analyzed, BMI was most strongly associated with hypertension [31]. Therefore, it is very important to prevent excess weight gain in
The result of our study confirms that there is a significant high prevalence of childhood prehypertension and hypertension among Egyptian school children from Cairo, Egypt. To review, in the present study, we found that obesity, and positive family history of hypertension were found to be associated with hypertension in children. Obesity and positive family history of hypertension are the most important contributing factors for childhood prehypertension and hypertension. Prevention and control mechanisms are needed in Egypt in order to decrease the number of children developing hypertension as adults.