| Abstract|| |
Hypertension is a major risk factor for heart disease, stroke, kidney failure, and premature death. In Saudi Arabia, studies looking at the prevalence of hypertension in young adults are scarce. We aim to provide current data on the prevalence and associated risk factors of hypertension in young adults to allow us to assess the magnitude of the problem in this age group and suggest the appropriate recommendations to physicians and policymakers. The objective of the study is to assess the prevalence of hypertension and its associated risk factors in medical students attending the College of Medicine in Qassim University, Qassim, Saudi Arabia. It is a cross-sectional study that was conducted during the year 2017 on medical students attending the College of Medicine at Qassim University. A total of 130 students were selected using multistage stratified random sampling. We collected data on sociodemographic information and risk factors using a self-administered questionnaire derived from the WHO STEPS instrument, and we measured the blood pressure and body mass index (BMI) of the participants. Data were analyzed using Statistical Package for Social Sciences version 23.0. The prevalence of hypertension in the study sample was found to be 14.6%, 6.9% of which had isolated diastolic hypertension while 4.6% had isolated systolic hypertension, and the remaining 3.1% had systolic-diastolic hypertension. The prevalence of prehypertension was found to be 29.2%. Only 21.1% of the participants found to be hypertensive were diagnosed and on antihypertensive therapy. We found a significant association between gender, BMI, and history of diabetes and hypertension. Our study confirms the notion that there are high rates of prehypertension and hypertension among young adults, the majority of which are undiagnosed cases. This calls for the need of a comprehensive national screening program and campaigns that increase awareness about hypertension and its associated risk factors.
|How to cite this article:|
AlWabel AH, Almufadhi MA, Alayed FM, Aloraini AY, Alobaysi HM, Alalwi RM. Assessment of hypertension and its associated risk factors among medical students in Qassim University. Saudi J Kidney Dis Transpl 2018;29:1100-8
|How to cite this URL:|
AlWabel AH, Almufadhi MA, Alayed FM, Aloraini AY, Alobaysi HM, Alalwi RM. Assessment of hypertension and its associated risk factors among medical students in Qassim University. Saudi J Kidney Dis Transpl [serial online] 2018 [cited 2019 Feb 21];29:1100-8. Available from: http://www.sjkdt.org/text.asp?2018/29/5/1100/243959
| Introduction|| |
Hypertension is a major risk factor for heart disease, stroke, kidney failure, and premature death. It poses a great burden on both the health system and the economy. Globally, hypertension accounts for 9.4 million deaths every year. Hypertension has been called the Silent killer because it is rarely symptomatic, and can lead to life-threatening complications. Early detection and management of hypertension are thus of extreme importance. In Saudi Arabia, the prevalence of hypertension according to a recent national survey was 15.2%, of those, 57.8% were undiagnosed. This is surprising in a high-income country with free medical care. Although hypertension has its lowest prevalence in young adults compared to middle-aged adults and elderly, early diagnosis and appropriate management of these cases can prevent future complications. Moreover, young adults can achieve better hypertension control and within a shorter time compared to older adults. In addition, prehypertension, which is more prevalent in young adults than full-blown hypertension, is an important antecedent for developing hypertension and cardiovascular disease later in life, and when detected early, it can be lowered, although not always reliably, by lifestyle modifications.,, Despite this, screening for prehypertension and hypertension in this age group is lacking, and physicians are more hesitant to initiate antihypertensive medications to hypertensive young adults compared to older adults., In addition, modification of hypertension-related risk factors is an important tool in preventing hypertension and achieving a better blood pressure control. Risk factors include high-salt diet, obesity, physical inactivity, low fruit and vegetable intake, and excess alcohol intake. Several studies had looked at the prevalence of hypertension in medical students. Studies that were conducted outside Saudi Arabia showed a varied prevalence of hypertension among medical students ranging between 6% and 21.33%.,,, In Saudi Arabia, a study that had looked at the risk factors of coronary heart disease among medical students in Jeddah revealed a prevalence of hypertension of 9.3%. In our study, we assessed the prevalence of prehypertension and hypertension and its related risk factors among medical students in Qassim University.
| Methods|| |
Study design, setting, and population
It is an institution-based cross-sectional study that was conducted on medical students attending the College of Medicine at Qassim University between July and August 2017. The study population included all medical students enrolled in the basic and clinical years (1st–5th year).
Sampling technique and sample size
The study participants were selected using multistage stratified random sampling. Stratification was done according to gender and educational year. In the first stage, stratification was done according to gender. The second stage of stratification was done according to educational year. The calculated sample size was 130 samples using the following formula.
Sample size: n = Z2P (1 − P)/d2
Z = standard normal variate (at 5% type I error is equal to 1.96), P = the expected proportion based on a previous study is 9.3%, d = absolute error or precision is 5%.
Data collection methods
- Self-administered questionnaire: participants were handed a questionnaire with questions derived from the WHO STEPS instrument to collect data on sociodemographic information (age, gender, marital status, and educational year), smoking status (number of cigarettes/day, smoking duration, and other forms of tobacco), diet (frequency of fruits and vegetables intake), physical activity (type and frequency of physical activity, and sedentary behavior), history of hypertension (including medications or advices received, and family history of hypertension) , and history of diabetes
- Blood pressure measurement: blood pressure measurement was carried out by trained medical students as per the American Heart Association guidelines
- Weight and height measurement: weight and height were measured, and the body mass index (BMI) was calculated during the analysis using the following the formula:
BMI = weight (kg)/height (m)
| Statistical Analysis|| |
Data were analyzed using Statistical Package for the Social Sciences (IBM Corp. Released 2015. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp). The following was done:
- Hypertension and prehypertension were both defined and classified according to “The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure” or “JNC-7”: Prehypertension was defined as systolic blood pressure 120–139 mm Hg or diastolic blood pressure 80–89 mm Hg. Hypertension was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg
- BMI was classified according to the WHO adult BMI classification into normal (18.50–24.99), overweight (≥25), and obese (≥30)
- Cross-tabulation and Chi-square test of significance were done between gender, BMI, physical activity, fruits and vegetables intake, history of diabetes, family history of hypertension and the prevalence of prehypertension and hypertension.
Ethical approval was obtained from the Qassim Region Research Ethics Committee (QREC). Informed written consent following the guidelines of the QREC was obtained from participants before administering the questionnaire.
| Results|| |
The study’s participants consisted of 130 medical students (mean age = 22.45 ± 1.67, range = 19-27), 92 of which (70.8%) were males and 38 (29.2%) were females. [Table 1] shows the sociodemographic characteristics of the study participants. According to the educational year, 16.9%, 16.2%, 12.3%, 26.9%, and 27.7% of the study participants were enrolled in 1st, 2nd, 3rd, 4th, and 5th year of medical school, respectively. Regarding BMI, 44.6% of the participants were of normal weight, while 26.2% and 22.3% were overweight, and obese, respectively. There were very low rates of smoking (1.5%) among the study participants.
Following the JNC-7 definition of prehypertension and hypertension, the prevalence of hypertension in the study sample was found to be 14.6% [Table 2], 6.9% of which had isolated diastolic hypertension (IDH), while 4.6% had isolated systolic hypertension (ISH), and the remaining 3.1% had systolic-diastolic hypertension (SDH). Only 21.1% of those found to be hypertensive were already diagnosed cases and on antihypertensive therapy. As for prehypertension, the prevalence was found to be 29.2%.
|Table 2: The prevalence of hypertension and prehypertension in the study sample.|
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When looking at the relationship between gender and hypertension, hypertension was found to be much more prevalent in male participants (18.5%) compared to female participants (5.3%) with a statistically significant difference (P <0.05) as demonstrated in [Figure 1]. The same relationship was observed when comparing prehypertension rates between male and female participants.
Concerning the relationship between BMI and hypertension, we found that the rates of hypertension among obese participants were much higher (34.5%) compared to participants with normal weight (8.6%) as shown in [Figure 2] with the association being statistically significant (P <0.05). However, among overweight participants, the rates of hypertension were similar to that of normal weight participants.
Pearson’s r data analysis was done to assess the relationship between body weight and the average systolic and diastolic readings of the study participants. The result showed a moderately positive correlation between body weight and average systolic (r = 0.474) and diastolic (r = 0.414) values (P <0.01).
Family history of hypertension and physical activity were not found to be associated with hypertension in our study.
Multivariate logistic regression model of risk factors for hypertension and prehypertension can be found in [Table 3] and [Table 4].
|Table 3: Multivariate logistic regression of risk factors for hypertension.*|
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|Table 4: Multivariate logistic regression of risk factors for prehypertension.*|
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| Discussion|| |
Our study showed high rates of hypertension (14.6%) among medical students. Only 21.1% of which were diagnosed and on antihypertensive therapy. This is alarming and shows that hypertension in young adults is an overlooked problem. In addition, physicians are more hesitant to prescribe antihypertensive medications to young adults, even though, they can achieve better control compared to older adults. This emphasizes the need of screening and early detection of hypertension among young adults. We also found high rates of prehypertension (29.2%) in the study sample, this is concerning as prehypertension is an important antecedent for developing hypertension and cardiovascular disease later in life, and when detected early can be lowered with lifestyle modifications without the use of antihypertensive medications, although not always reliably.,
Only a few studies assessing the prevalence of hypertension in young adults were conducted in Saudi Arabia. Our results are consistent with a national survey conducted by El Bcheraoui et al that reported a prevalence of 13.34% among the age group 15–24 (n = 848). In the same study, the prevalence of hypertension in the general population aged 15 years old and above (15.2%) was also similar to our result. Another study that was done among university students in Dammam, Saudi Arabia reported a comparable overall prevalence with a prevalence of 13.8% for systolic hypertension and 3.7% for diastolic hypertension. A recent study done in Kampala, Uganda among medical students showed a similar hypertension prevalence of 14%. Lower rates of hypertension (9.3%) among medical students in Jeddah were reported by Ibrahim et al. This difference might be due to the fact that unlike our sample, the majority of their sample consisted of female medical students who have lower rates of hypertension compared to males.
We also observed higher rates of IDH (6.9%) compared to ISH (4.6%) and SDH (3.1%). These findings are in accordance to what was reported by two studies based on the Framingham Heart Study and the National Health and Nutrition Examination Survey III.,
Both studies reported higher rates of IDH among young adults compared to older adults. This is because increased peripheral resistance is thought to be the hemodynamic mechanism underlying hypertension in young adults which explains the higher rates of IDH among this population. In contrast, increased stiffness of the elastic arteries in older adults leads to the development of ISH which is the main form of hypertension seen in people >60 years old.
Our work showed a higher prevalence of hypertension among males (18.5%) compared to females (5.3%). This is consistent with multiple studies reporting on hypertension.,, For example, comparable prevalence rates (20.8% in males, 5.8% in females) were presented by Ibrahim et al. This gender difference in the prevalence of hypertension is observed up to the age of menopause. After menopause, the blood pressure in females increases even higher than it does in males. The mechanism underlying this gender difference has not been elucidated yet; however, there is strong evidence implicating the role of androgens in blood pressure regulation differences between genders.
There was a strong association between BMI and hypertension in our study. The prevalence of hypertension was found to be 34.4% among obese participants (BMI ≥30) compared to a prevalence of 8.6% among participants with normal weight (BMI <25). To further assess this relationship, we looked at the strength of the correlation between body weight and average systolic and diastolic values which showed a moderately positive correlation. Many studies had shown BMI to be a strong predictor of hypertension, more specifically, BMI is a strong predictor of new-onset IDH and SDH.,,, Although the exact mechanism by which increased body weight lead to hypertension is not entirely clear, previous research suggest that in obese individuals, the combination of increased sympathetic activity, insulin resistance, and increased leptin levels to be the main culprit.,
We found very low rates of diabetes mellitus in our study sample (1.6%) which is expected in a young population. All cases of diabetes mellitus that were found during the study were also co-diagnosed with hypertension. Although we cannot reliably infer any conclusion about the association between diabetes and hypertension due to the small number of diabetic cases found during our study, previous studies support our findings of a strong association between diabetes mellitus and hypertension. In fact, diabetes mellitus is a well-recognized risk factor for developing hypertension, and the rates of hypertension among diabetic patients are 2 times the rates in nondiabetic patients. This is important as co-existing diabetes, and hypertension markedly increase the risk for coronary artery disease and henceforth increase the rates of morbidity and mortality among diabetics.,
In contrast to other studies, we found no significant association between family history of hypertension in first-degree relatives and hypertension. Several studies have reported that family history of hypertension in first-degree relatives is an independent predictor of developing hypertension, and what is shared between these studies is that they had a much older population with a mean age of around 45 years old.,, It could be that in young adults, family history of hypertension in first-degree relatives does not play a significant role as a predictor of developing hypertension in this age group. In addition, family history of hypertension as a risk factor might need time to manifest itself which may explain the lack of a significant association in younger adult. Plus, secondary causes of hypertension are more likely in the younger patient.
| Conclusion|| |
Hypertension is an overlooked problem in young adults. Our study confirms the notion that there are high rates of prehypertension and hypertension among young adults, the majority of which are undiagnosed cases. This calls for the need of a comprehensive national screening program, and campaigns that increase awareness about hypertension and its associated risk factors. Although young adults form a small proportion of hypertensive patients, early detection of hypertension and initiation of antihypertensive medications reduces future complications, plus, hypertensive young adults can achieve better control and within a shorter time.
| Limitations|| |
There were more male participants in the study than female participants as males had a higher participation rate compared to females in our study. This may affect some of the measured parameters such as blood pressure and BMI.
In addition, our study is a cross-sectional study, and as such, causation cannot be assessed. Another limitation is that several parameters of the study were based on self-report and are subject to recall bias.
Conflict of interest: None declared.
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Dr. Ahmed Humaidan AlWabel
College of Medicine, Qassim University, Qassim
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]