• Users Online: 1316
  • Print this page
  • Email this page


 
 
Table of Contents
ORIGINAL ARTICLE
Year : 2013  |  Volume : 1  |  Issue : 2  |  Page : 104-109

Prehypertension and its correlation with cardiovascular risk factors – A study among health sciences students in Malaysia


1 Senior Lecturer, Department of Pathology, School of Medicine, Taylor’s University, Subang Jaya, Malaysia
2 Student, Department of Pathology, School of Medicine, Taylor’s University, Subang Jaya, Malaysia

Date of Web Publication21-Aug-2018

Correspondence Address:
Mohit Shahi
Senior Lecturer, Department of Pathology, School of Medicine, Taylor’s University, Subang Jaya
Malaysia
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2347-6486.239491

Rights and Permissions
  Abstract 


Introduction: The levels of blood pressure (BP) are important as it is a potential risk factor that predisposes towards cardiovascular disease (CVD) when the levels are high. After the introduction of the term prehypertension by Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7) (2004), there are heightened interests on the correlation between high-normal levels of BP with CVD risk factors.
Methodology: A questionnaire containing information about eating habits, family history and social habits was given out. Other than that, anthropometric measurements were taken according to the protocol provided by the United States Institutes of Health.
Results: There were a total of 87 respondents that participated in the study. The overall prevalence of prehypertension and hypertension was 40.2% (46.9% - males; 32.7% - females) and 2.3% (male) respectively. Also, it was found that 57.1% of male and 40% of female with increased WC and 75% of male and 33.3% of female with increased WHR have prehypertension. It was also found that subjects with a positive family history of hypertension, diabetes and stroke have a higher tendency towards prehypertension.
Conclusion: There is a high prevalence of prehypertension among males compared to female and that there are positive correlations between the CVD risk factors with prehypertension.

Keywords: Prehypertension, hypertension, risk factors, cardiovascular


How to cite this article:
Shahi M, Li CW. Prehypertension and its correlation with cardiovascular risk factors – A study among health sciences students in Malaysia. J Integr Health Sci 2013;1:104-9

How to cite this URL:
Shahi M, Li CW. Prehypertension and its correlation with cardiovascular risk factors – A study among health sciences students in Malaysia. J Integr Health Sci [serial online] 2013 [cited 2021 Nov 30];1:104-9. Available from: https://www.jihs.in/text.asp?2013/1/2/104/239491




  Introduction Top


People having a systolic blood pressure (SBP) ranging from 120mmHg - 130mmHg and/or diastolic blood pressure (DBP) ranging from 80mmHg - 89mmHg fit into the criteria of prehypertension.[1],[2] As reported by the Seventh Report of the Joint National Committee (JNC7) on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, identification of prehypertension would be facilitatory in the prevention of hypertension or slow the rate of progression of BP to hypertensive levels in adolescence through interventions via adoption of healthy lifestyle.[2]

The measurements that are needed to assess the risks involved are body mass index (BMI), waist-hip ratio (WHR) and waist circumference (WC).[3],[4] Also, random blood glucose test is done as an important step in assessing the risk of CVD in a primary health care setting.[5]

The National High Blood Pressure Education Program’s (NHBPEP) Working Group on Hypertension Control in Children and Adolescents had categorised BP between the 90th and 95th percentile in childhood as “prehypertensive” and is an indication for lifestyle modifications.[6] Moreover, prehypertension also predisposes to hypertension.[6],[7] Framingham Heart Study showed that 90% of subjects aged ≥ 55 years had previously been prehypertensive before developing hypertension.[1] This is important as adolescents may have target organ damage when they are diagnosed with prehypertension.[8] Also, prehypertensives have twice the risk of developing hypertension and subsequently CVD, as compared to normotensives.[9]

In the South East Asia region, around 152,000 people die each year from hypertension.[10] Cannon & Vierck stated that “When high BP exists with few or none of the other risk factors, the overall risk is relatively less. But if other risk factors are present the CVD risk increases several folds”.[11] It therefore becomes necessary to acknowledge the role of other risk factors too. These include obesity, cigarette smoking and type2 diabetes with obesity being the most predominant risk factor for CVD among adolescents.

[4],[10],[13],[14]

Recently, various data has shown that essential hypertension can be detected during childhood and adolescent stage and there is a strong link between BMI and BP.[3] The risk of CVD is linked with central obesity (high-risk WC), which can be measured by anthropometric indices such as WC, hip- circumference and WHR.[12],[15] Obesity can also easily be determined through measuring BMI. However, BMI could not accurately assess whether the BMI measured is due to adipose obesity or lean muscle mass as compared to WHR which could be an independent predictor of CVD.[16]

Diabetes, is diagnosed as fasting blood glucose level of ≥ 7.0mmol/L and glucose tolerance level of ≥ 1 l.lmmol/L.[17] A recent survey showed that more than 65% of diabetics do not consider CVD as a severe complication as a consequence of diabetes and only 18% believe that it is indeed a risk factor for CVD.[11]

The prevalence of hypertension amongst the diabetic population is 1.5-3 times greater than that of the non-diabetic population. It was estimated that around 73% of diabetic patients have BP ≥ 130/80mm Hg which is considered as prehypertension based on JNC7 classification of BP .[11]

Risk factors such as smoking, alcohol consumption, obesity, hypertension, a high lipid profile and diet accounts for up to 90% of CVDs worldwide.[18] As compared to normotensives, prehypertensive people are 1.32 times as likely to develop a major cardiovascular event.[7] This correlation is important as results from the Prospective Studies Collaboration (2002) have found that by reducing the SBP by 20mmHg and DBP by 10mmHg would greatly reduce the mortality of CVD by one-half in the middle-aged population.[7],[19]

Smokers and people who drink alcohol often have a higher progression rate towards hypertension from prehypertension.[9] Furthermore the prevalence of diabetics who are prehypertensive is 59.4% as compared to non-diabetic people. High BMI and abnormal WHR were found to have an odds ratio (OR) of 4. and 2.7 in developing prehypertension and hypertension respectively.[20]


  Methods Top


This study was a cross-sectional survey on the correlation between prehypertension and cardiovascular risk factors carried out in Taylor ' s University Lakeside Campus from 29th June 2012 to 13 th July 2012 among the health science students in Taylor ' s University. A total of 194 sample size was obtained with a 45% response rate.An institutional ethical clearance and informed consent were obtained.

A questionnaire containing items asking about family history, social history such as smoking and drinking alcohol and eating habits were included. The last section was on eating habits with 23 items which was developed by Johnson, Wardle and Griffith .[21]

Furthermore; measurements were obtained from the subjects including BP, random blood glucose, fasting blood glucose, WC, HC, WHR and BMI.

The individuals were classified as normal, prehypertensive and hypertensive based on the classification given by JNC 7.[2] The BMI was measured and subjects were classified as underweight, normal, overweight and obese by using the BMI cut-off point.[22]

Also, the waist and hip circumference was obtained and WHR calculated by using the waist circumference divided by the hip circumference. The WC is measured by placing the measuring tape on top of the iliac crest.[22] The HC was obtained by placing the measuring tape around the widest part of the gluteal region. The cut-off point for classifying the risk they carry based on their WHR calculated is obtained from the WHO report on the WC and WHR.[22] The WC cut-off point was designated into two categories namely increased risk and substantially increased risk. For males, WC of >94cm was considered as increased risk and >104cm as substantially increased risk. For females, WC of >80cm was deemed as increased risk and >88cm as substantially increased risk for developing metabolic disorders.[22]

Furthermore, the random and fasting blood glucose was obtained via finger prick by using the lancet pen and glucometer. The data collected was analysed using the Microsoft Excel. The prevalence of prehypertension was measured and compared with their WHR, waist circumference, BMI status, family history, alcohol intake and diet.


  Result Top


Out of 195 subjects, 87 responded to the survey with response rate at approximately 45 %. There were 32 males and 55 females. Most of the respondents were of Chinese ethnic group followed by Malay, Indian and others.

The overall prevalence of prehypertension and hypertension is 40.2% and 2.3% respectively. Also, 46.9% of males and 32.7% of female are prehypertensive; 6.25% of males and none of the females were hypertensive.

There is a substantially higher number of prehypertensives among the normal range of BMI compared to the others as shown in [Table 1]. Other than that, it was found that among the 87 subjects there were 2 subjects (normal BMI and overweight respectively) whose blood pressure is classified under hypertension. The prevalence of people under each category is also shown in [Table 1].
Table 1: Percentage of people being prehypertensive based on BMI

Click here to view


Based on the measurement of waist-circumference, 72 subjects were normal whereas a total of 15 subjects were at an increased risk and substantially increased risk.

A total of 9 subjects were prehypertensives with the proportion of female higher than male. Also, only females were found to be under the category of substantially increased risk for CVD as shown in [Figure 1].
Figure 1: Waist-circumference and its relation with prehypertension

Click here to view


As shown in [Figure 2], a small proportion of them have an increased risk of developing disease based on the measurement of WHR. From the data collected, 6 males were found to be prehypertensive and 2 males were hypertensive. Also, for females there were 3 who were classified as prehypertensive.
Figure 2: Category of risk according to WHR measurement

Click here to view


Most have a family history of high blood pressure followed by diabetes and stroke as compared to the other diseases. From the data, it is also observed that a large proportion of the subjects do not have a positive family history of heart attack followed by stroke and obesity.

Comparison between the associations of family history with blood pressure levels is as shown in [Figure 3] and [Figure 4]. It is seen from [Figure 3] that people with prehypertension tend to have a positive family history of high blood pressure, heart attack and obesity compared to other diseases. Whereas [Figure 5] shows people who do not have a positive family history of those listed showed a steady number of prehypertensives with no inclination towards any family history.
Figure 3: Association of blood pressure with positive family history

Click here to view
Figure 4: Association of blood pressure with negative family history

Click here to view
{Figure 5}

The mean value for fasting blood glucose and random blood glucose is as shown in [Table 2]. The mean for both males and females were calculated and the mean random blood glucose of male is much higher than female whereas the mean for fasting blood glucose showed that females have a marginally higher mean than males.
Table 2: Glucose measurement and mean of fasting and random blood glucose

Click here to view


In terms of diet, the effect of diet on those who are prehypertensive is as shown in [Table 3]. It is observed a slightly higher proportion of them have answered yes to questions involving increased fat and sugar intake.
Table 3: Choice of diet in those who are prehypertensive

Click here to view


None of the subjects had smoked and 24.1% of them consume alcohol out of which, 38.1% of the subjects are prehypertensive.


  Discussion Top


The results of this study have indicated that males (46.9%) have a higher prevalence rate of prehypertension than females (32.7%). It also showed that males have a higher tendency to have hypertension compared to females as 6.25% of male were found to have BP levels categorised as hypertension. This is consistent with Cannon & Vierck’s[11] statement that males generally have a higher predisposition towards CVD. However, the results do not agree with those by Ganguly et al[20] which states that the prevalence of females is marginally higher than males. On the other hand, this result is also significant based on Vasan et al’s[23] findings that elevated BP in both genders has an increased predisposition towards a CVD on follow-up.

17.1% of prehypertensive subjects have high BMI as a risk factor. In contrast, 71.4% of subjects under the category of normal BMI are prehypertensive. This does not coincide with Ganguly et al’s[20] report that people with higher BMI have a higher odd’s ratio of developing prehypertension. However, it is said that Asians have a higher percentage of body fat even with low BMI.[22] Therefore, the measurement of WC and WHR is more accurate in predicting CVD risk factors as it gives a more accurate estimate of visceral body. It was found that there are more males under the ‘increased risk’ category whereas only females fall under ‘substantially increased risk’ category which places female under a higher risk in terms of WC measurement. When it is correlated with the state of their BP status, 57.1% of males under the ‘increased risk’ category have prehypertension whereas 40% of females have prehypertension under the same category; all the females who were under the ‘substantially increased risk’ category were classified as prehypertensive. On the other hand, the measurement of WHR and its correlation with BP shows that 75% of males and 33.3% of females who are categorised as having increased risk have prehypertension and 25% of male have hypertension under the same category. This finding would be consistent with the data provided by WHO22 whereby the positive correlation between higher WC and WHR with the end-result of elevated BP is convincing.

Based on the data obtained, those with a positive family history of hypertension had the highest number of prehypertensives followed by diabetes, stroke, obesity and lastly heart attack. This corresponds to the study by Cannon & Vierck[10] that heart disease tends to run in families and that it is positively correlated with increased risk of CVD. Although many that are prehypertensive do not have a family history of aforementioned diseases, it may be due to a background risk that may be due to other risk factors attributed to their rise in BP.

The fasting blood glucose was obtained from 31 subjects whereas random blood glucose was obtained from 56 subjects. The mean value is obtained for both male and female from both categories. Under fasting blood glucose, females have a higher mean value than males with mean values of 4.30mmol/L and 4.29mmol/L respectively. Besides that, the mean value of random blood glucose for male is much higher than that of female with a mean value of 5.21mmol/L and 4.86mmol/L respectively. Since both mean values for each category does not meet the criteria of prediabetes or diabetes, there is no positive correlation found between the levels of blood glucose with prehypertension. Therefore, this finding would be consistent with the finding from Zhang et al[17] that a high proportion of non-diabetics have prehypertension.

Based on the data collected about the diet of the subjects, 42.8% who have increased fat intake and 45.7% of them who have increased sugar intake are prehypertensives. Similarly, 40% and 34.2% who did not have increased fat and sugar intake respectively, have prehypertension. Regarding the intake of vegetable and fibre in their daily diet, 42.8% of them had indeed increased their intake and 51.4% of them who did not are prehypertensive. As increased fat and sugar intake is associated with the development of obesity and diabetes, this finding would indirectly correlate with the statement that diabetes and obesity does play a role in the elevation of BP.[15],[24]

Since none of the subjects who participated in this study smoked, there are no data available to compare with. In contrast, it is found that 24.1% of the subjects do drink alcohol from time to time. Among those who drink alcohol, 38.1% of them are considered as having prehypertension and 61.9% of them are within the optimal BP range. This finding agrees with the finding stated by Cannon & Vierck[11] that drinking alcohol in moderate amount have a protective effect as those in the normal BP range drinks only minimal amount of alcohol infrequently. Although those in the 38.1% who are prehypertensive do not drink much alcohol as well, there may be other factors that are influencing the BP levels at the same time.


  Conclusion Top


The conclusion drawn from this study is that the prevalence of prehypertension among the students is high with the overall prevalence at 40.2%. This finding is significant as prehypertension is seen as a factor that would increase the predisposition towards hypertension upon reaching adulthood. High BMI is not associated with prehypertension. WHR and positive family history are effective tool to predict a positive correlation with CVD and hypertension. Diet has a great influence blood pressure regulation.



 
  References Top

1.
Grotto I, Grossman E, Huerta M, Sharabi Y. Prevalence of prehypertension and associated cardiovascular risk profiles among Young Israeli adults.Hypertension. 2006; 48(2): 254-59.   Back to cited text no. 1
    
2.
The Seventh Report of the Joint National Committee. Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA-J Am Med Assoc. 2003; 289: 2560–72(PR).  Back to cited text no. 2
    
3.
Rafraf M, Gargari BP, Safaiya A. Prevalence of prehypertension and hypertension among adolescent girls in Tabriz, Iran. Food Nutr Bull. September 2010; 31 (3): 461-65(5).  Back to cited text no. 3
    
4.
Clarke R, Emberson J, Fletcher A, Breeze E, Marmot M, Shipley MJ. Life expectancy in relation to cardiovascular risk factors: 38 year follow-up of 19000 men in Whitehall study. Brit Med J. 2009; 339: b3513.  Back to cited text no. 4
    
5.
Joint British Society’s guidelines on Prevention of Cardiovascular Disease in Clinical Practice. Heart. 2005; 91(5).   Back to cited text no. 5
    
6.
The Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. Pediatrics. 2004; 114(S2): 555-76.   Back to cited text no. 6
    
7.
Liszka HA, Mainous AG 3rd, King DE, Everett CJ, Egan BM. Prehypertension and cardiovascular morbidity. Ann Fam Med. 2005;13:294–299.   Back to cited text no. 7
    
8.
Abolfotouh M, Al-Alwan I, Al-Rowaily M. Prevalence of metabolic abnormalities and association with obesity among Saudi college students. Int J Hypertens 2012;2012:819726   Back to cited text no. 8
    
9.
Kim SJ, Lee J, Jee SH, Nam CM, Chun K, Park IS, et al. Cardiovascular risk factors for incident hypertension in the prehypertensive population. Epidemiol Health. 2010;32:e2010003.  Back to cited text no. 9
    
10.
World Heart Federation (2012). Retrieved 8th July 2012, from, < http://www.world-heart- federation.org/cardiovascular-health/global-facts-map/>   Back to cited text no. 10
    
11.
Cannon CP, Elizabeth V. The New Heart Disease Handbook: Everything You Need to Know to Effectively Reverse and Manage Heart Disease. Beverly, MA: Fair Winds Press, 2009   Back to cited text no. 11
    
12.
Ferguson TS, Younger NO, Tulloch-Reid MK, Wright MB, Ward EM, Ashley DE, et al. Prevalence of prehypertension and its relationship to risk factors for cardiovascular disease in Jamaica: analysis from a cross-sectional survey. BMC Cardiovasc Disord. 2008;8:20.  Back to cited text no. 12
    
13.
Hayman LL, Wiliams CL, Daniels SR, Steinberg J, Paridon S, Dennison BA. Cardiovascular health promotion in the schools. Circulation 2004, 110:2266-75.   Back to cited text no. 13
    
14.
May AL, Kuklina EV, Yoon PW. Prevalence of cardiovascular disease risk factors among US adolescents, 1999-2008. Pediatrics. 2012;129:1035–104.  Back to cited text no. 14
    
15.
Mushtaq MU, Gull S, Abdulla HM, Shahid U, Shad MA, Akram J. Waist circumference, waist- hip ratio and waist-height ratio percentiles and central obesity among Pakistani children aged five to twelve years. BMC Pediatr 2011, 11:105.   Back to cited text no. 15
    
16.
Cannon CP, Steinberg BA. Evidence based cardiology. 3rd Ed. Philadelphia: Lippincott Williams & Wilkins; 2011.   Back to cited text no. 16
    
17.
Zhang Y, Lee ET, Devereux RB, Yeh J, Best LG, Fabsitz RR, Howard BV. Prehypertension, diabetes, and cardiovascular disease risk in a population-based sample: the Strong Heart Study. Hypertension. 2006; 47: 410–14.  Back to cited text no. 17
    
18.
BeLue R, Okoror TA, Iwelunmor J, Taylor KD, Degboe AN, Agyemang C, et al. An overview of cardiovascular risk factor burden in sub-Saharan African countries: a socio-cultural perspective. Globalization and Health. 2009.5:10.   Back to cited text no. 18
    
19.
Lewington S, Clarke R, Qizilbash N, Peto R, Collins R. Age-specific relevance of usual blood pressure to vascular mortality: A meta-analysis of individual data for one million adults in 61 prospective studies. Prospective Studies Collaboration. Lancet. 2002;360:1903-13.   Back to cited text no. 19
    
20.
Ganguly SS, Al-Shafaee MA, Bhargava K, Duttagupta KK: Prevalence of prehypertension and associated cardiovascular risk profiles among prediabetic Omani adults. BMC Public Health. 2008;8:108-9.  Back to cited text no. 20
    
21.
Johnson F, Wardle J, Griffith J. The adolescent food habits checklist: reliability and validity of a measure of healthy eating behaviour in adolescents. Eur J Clin Nutr 2002; 56 (7): 644-9.   Back to cited text no. 21
    
22.
World Health Organization (WHO): Waist circumference and waist-hip ratio: report of a WHO expert consultation. Geneva, 8–11 December 2008. Geneva: WHO; 2011.   Back to cited text no. 22
    
23.
Vasan RS, Larson MG, Leip EP, Evans JC, O’Donnell CJ, Kannel WB, et al. Impact of high- normal blood pressure on the risk of cardiovascular disease. N Engl J Med. 2001; 345: 1291–7.   Back to cited text no. 23
    
24.
Rao SS, Disraeli P, Mcgregor C. Impaired glucose tolerance and impaired fasting glucose. Amer Fam Phys. 2004; 69:8.  Back to cited text no. 24
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]


This article has been cited by
1 Prevalence and risk factors of prehypertension in university students in Sabah, Borneo Island of East Malaysia
Shazia Qaiser,Mohd Nazri Mohd Daud,Mohd Yusof Ibrahim,Siew Hua Gan,Md Shamsur Rahman,Mohd Hijaz Mohd Sani,Nazia Nazeer,Rhanye Mac Guad
Medicine. 2020; 99(21): e20287
[Pubmed] | [DOI]
2 A STUDY OF LIPID PROFILE, BMI, PREHYPERTENSION AND INTIMA MEDIA THICKNESS IN MEDICAL STUDENTS OF COASTAL ANDHRA PRADESH
Shakeela D,Raja Babu P
Journal of Evolution of Medical and Dental Sciences. 2015; 4(101): 16680
[Pubmed] | [DOI]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
Abstract
Introduction
Methods
Result
Discussion
Conclusion
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed976    
    Printed52    
    Emailed0    
    PDF Downloaded83    
    Comments [Add]    
    Cited by others 2    

Recommend this journal