Prevalence and Risk Factors of Hypertension and Associated Factors

Introduction

Cardiovascular disease (CVDs) is the primary cause of morbidity and mortality worldwide, and hypertension is the major predisposing factor for most cardiovascular diseases such as coronary artery disease, stroke, peripheral vascular disease, and arterial fibrillation.¹

Hypertension (HTN) is the most prevalent preventable risk factor that causes a significant socioeconomic burden associated with CVDs and is the single most common cause of heart failure and myocardial infarction.² HTN was defined as a diastolic blood pressure ≥ 90 mmHg and/or systolic blood pressure ≥ 140 mmHg. The incidence rates of hypertensive cases are increasing worldwide, across all people of different socioeconomic backgrounds, and among all regions owing to the rapid rise in urbanization and economic progress.³ HTN is the third major contributor to global disease after underweight and unsafe sex.³

Sub-Saharan countries, including Uganda, are still among the worst hit in terms of CVD mortality rates due to hypertension.⁴ More than 15 million global disability-adjusted life-years in sub-Saharan Africa are attributable to HTN; thus, identifying factors associated with the progressive surge in the burden of HTN in the region is vital for providing information regarding targeted public health interventions.⁵ Globally, the four major risk factors for hypertension and CVDs are tobacco use, unhealthy diet, sedentary lifestyle, and harmful alcohol consumption.⁶ In addition, demographic factors, such as population aging and population growth, and epidemiologic factors, such as a shift to Western diets and lifestyles, have also been suggested to contribute to the surge of HTN in sub-Saharan Africa.⁷

An international perspective has indicated that the working population is a high-risk group for HTN due to predisposition to numerous risk factors, such as smoking, high body mass index (BMI), and pre-hypertension (systolic blood pressure of 120-139 mmHg and/or a diastolic blood pressure of 80-89 mmHg).⁸ Other risk factors that predispose the general population to hypertension include diabetes, obesity, overweight sleep apnea, high salt intake, alcohol consumption, elderly populations (advanced age), smoking, and lack of physical activity.⁹ However, unlike Western countries, African countries have experienced progressive increases in morbidity and mortality due to HTN and associated CVDs, with an associated increase in premature deaths due to CVDs in the last two decades.¹⁰

In Uganda, the prevalence of HTN ranges from 11-32% among Ugandan populations, but no study has examined the magnitude of HTN among university employees, especially in the wake of the COVID19 pandemic that has resulted in most private university employees being owed salaries for several months due to lockdown restrictions.¹¹ A previous cross-sectional population-based study among adult and adolescent Ugandans determined the geographical variability of HTN among the different regions of Uganda and found that the prevalence of HTN was the highest among young adults aged 21–40 years in all four regions of Uganda (Central, East, West, and North).¹¹ This age bracket (21–40 years) forms the majority of staff strength in most private universities. Additionally, the University workplace is an ideal place for impacting knowledge and promoting health awareness.¹² However, little focus has been given to university occupational workers, especially those working in private universities during the COVID19 lockdown restrictions that have affected the salaries of this set of workers. Relevant information on the prevalence, determinants, and demographics of HTN in the University occupational population in a private setting is crucial for establishing targeted and effective workplace-based intervention policies and programs; this formed the basis for our study.

This study aimed to determine the prevalence of HTN and examine the risk factors associated with HTN in a sample of university employees at a private university in Uganda (Kampala International University, western campus).

Material and methods

Results

Clinical assessment

The majority had a normal systolic blood pressure (BP) of 155(100) when compared with age, especially age group 25-34 which is 82(52.9), followed by hypertension stage one 67(100), especially in the age group 35-44 which is 22(32.8). The majority had normal diastolic BP 121(100), especially age group 25-34 which is 55(45.5), followed by hypertension stage one 95(100), especially age group 25-35 which is 44(46.3). The females had more normal systolic BP than males 80(51.6) and 75(48.4), respectively, males had more normal diastolic BP than female 61(51.7) and 60(49.6), respectively ( Tables 8, 9, 10 and 11).

Table 8. Clinical assessment (reference table of blood pressure).

BLOOD PRESSURE	SYSTOLIC mmHg (Upper number)	DIASTOLIC mmHg (Lower number)
NORMAL/ELEVETED	≤ 129	≤ 80
HIGH BLOOD PRESSURE (HYPERTENSION) STAGE 1	130-139	81-89
HIGH BLOOD PRESSURE (HYPERTENSION) STAGE 2	140-179	90-119
HYPERTENSIVE CRISIS	≥180	≥120

Table 9. Comparison of blood pressure with age.

		Age (%)				Total	P-value	χ2
		≤ 24	25-34	35-44	≥45
Systolic	≤ 129	17(11)	82(53.2)	37(24.5)	18(11.7)	154(100)	0.000	30.263
	130-139	5(7.4)	21(30.9)	23(33.8)	19(27.9)	68(100)
	140-179	0(0)	0(0)	4(40)	6(60)	10(100)
Diastolic	≤ 80	17(14)	55(45.5)	32(26.4)	17(14)	121(100)	0.014	16.007
	81-89	3(3.2)	44(46.3)	29(30.5)	19(20)	95(100)
	80-119	2(12.5)	4(25)	3(18.8)	7(43.8)	16(100)
Total		22(9.5)	103(44.4)	64(27.6)	43(18.5)	232(100)

Table 10. Comparison of blood pressure with sex.

		Sex (%)		Total	P-value	χ2
		Male	Female
Systolic	≤ 129	74(48.1)	80(51.6)	154(100)	0.471	1.506
	130-139	38(55.2)	30(44.8)	68(100)
	140-179	6(60)	4(40)	10(100)
Diastolic	< 80	61(51.7)	60(49.6)	121(100)	0.622	0.950
	80-89	47(49.5)	48(50.5)	95(100)
	90-119	10(62.5)	6(37.5)	16(100)
Total		118(50.9)	114(49.1)	232(100)

Table 11. Mean blood pressure.

Average SBP	125.57 ± 0.513 mmHg
Average DBP	81.47 ± 0.326 mmHg
Mean SBP male	126.03 ± 0.762 mmHg
Mean DBP male	80.79 ± 0.784 mmHg
Mean SBP female	125.1 ± 0.684 mmHg
Mean DBP female	81.54 ± 0.447 mmHg

The mean blood pressure of female indicated that there was an increase in systolic and diastolic mean BP with increasing age. The mean blood pressure of males indicated an increase in mean systolic BP and an almost constant level of mean diastolic BP ( Table 11 and Figures 1 and 2).

Figure 1. Mean blood pressure of female.

Figure 2. Mean blood pressure of male.

Discussion

This study investigated the awareness of hypertension among university staff at Kampala International University (KIU). The findings of the study showed that 56.8% were not hypertensive, 37.5% did not know their status, and 5.6% were hypertensive within the age of 45 years and male. This indicates that awareness of hypertension was high among the respondents sampled for the study. This result supports previous findings documented at another University in Nigeria.¹⁴ According to our report, the majority last check their blood pressure about a year ago and within the age 25-34yrs. According to a study on the global epidemiology of hypertension, the majority of people do not regularly check their blood pressure even if they are aware that they are at risk of high blood pressure.¹⁵

Based on salt intake, 53.3% of the study population (n=232) had no knowledge of the quantity of salt they consumed daily, and the majority were males, while 15.9% reported that they consumed more than 6 g of salt daily. Participants who were in the 25-34 years’ age bracket were the most affected, and the majority of the respondents were female (58%). This is consistent with a previous study that reported poor knowledge of dietary salt intake in Uganda.¹⁶ Another study reported poor knowledge of the effect of diet on stroke risk among Ugandans.¹⁷ This lack of knowledge of salt intake and risk suggests that some Ugandans may consume more salt than the daily WHO requirement. A typical Ugandan food consists of plantains, roots, or tubers with low sodium; thus, salt added during cooking and table salt serve as the major sources of excessive sodium intake among Ugandans.¹⁸

Despite the reported higher mean levels of salt intake (3.95g/d) in Uganda compared to WHO standards, the mean salt intake reported in Uganda was fairly consistent with reports from other African countries such as Ghana which was documented to have 5.8g/d¹⁹; and Mauritius which was estimated to have 5.45g/d.²⁰ Excess salt intake has been implicated in high blood pressure and the onset of hypertension and cardiovascular complications,^21,22 and some authors have reported that excessive salt intake may induce several adverse effects such as microvascular endothelial inflammation, anatomic remodeling, and functional abnormalities even in normotensive subjects.²³ Therefore, the study suggests that there should be a change in dietary salt consumption habits in an effort to improve BP control and reduce the incidence of hypertension among staff.

Based on fruit or vegetable intake, 37.1% of the participants in the age bracket of 25-34 years consumed less than half a plate of fruits or vegetables, 35.3% were unsure of the quantity they consumed daily, and 27.6% of participants in the age bracket of 35-44 years consume more than half a plate of fruit and vegetables daily. Studies have proposed that vegetable-based diets can lower BP and the incidence of hypertension in persons compared to individuals who consume regular Western diets.^24,25 A study by²⁶ reported that fruit intake was more strongly and significantly associated with a lower risk of hypertension than vegetable intake. Similar weak associations between vegetable intake and a lower risk of hypertension have been documented elsewhere.^27,28 The reasons behind the participants in the age bracket of 25-34 years consuming less fruits and vegetables compared to those in the age bracket of 35-44 years may be due to the fact that younger individuals crave more for Western diets than the elderly.

Based on alcohol habits, 65.1% of the respondents reported that they did d not consume alcohol, 34.9% reported taking alcohol, and 19.8% reported taking alcohol for more than three years. The reported age bracket implicated in alcohol intake in this study was those within 25-34 years. Some researchers have suggested that low-to-moderate alcohol intake could be beneficial to the cardiovascular system and help lower blood pressure.²⁹ Alcohol has been used as an analgesic and is widely available to people with pain.³⁰ Chronic consumption of a high dose of alcohol has been associated with hepatic, gastrointestinal, nervous, and cardiovascular injuries and physiological dysfunction.³¹ Some clinical and epidemiological studies have documented that chronic alcohol intake is associated with an increased incidence of hypertension and increased risk of cardiovascular diseases.^32,33

Based on smoking habits, 62.9% of the respondents did d not smoke, 37.1% smoked, and 15.5% had been smoking for more than 3 years and were in the age bracket of 25-34 years. Several studies have reported evidence that cigarette smoking causes various adverse cardiovascular events^34,35 and synergistically acts with hypertension and dyslipidemia to increase the risk of coronary heart disease.³⁶ It has been established that smoking causes an acute increase in blood pressure and heart rate and this has been implicated in malignant hypertension.³⁷ Smoking is strongly associated with alcohol intake and similarly affects blood pressure in like manner.³⁸

Based on sports/physical activities, 71% of the respondents reported engaging in walking as a form of physical activity, 19.8% engaged in running, 2.6% engaged in swimming, 2.1% engaged in biking, and the majority were in the age bracket of 25-34 years. Exercise is documented to prevent or reduce the effects of metabolic and cardiovascular diseases such as hypertension.³⁹ Exercise alone or combined with lifestyle modification has been associated with a decrease in blood pressure and a reduced need for pharmacological therapy in patients with hypertension.⁴⁰ Exercise reportedly regulates autonomic nervous system activity, increases shear stress, improves nitric oxide production in endothelial cells and its bioavailability for vascular smooth muscle, and upregulates antioxidant enzymes.⁴¹

Based on clinical assessment it shows that majority have a normal systolic/diastolic blood pressure (BP) when compare to age especially age group 25-34, followed by hypertension stage one especially at age group 35-44, According to our data, elderly adults typically have greater blood pressure. As suggested in⁴²: High blood pressure, also known as hypertension, is particularly common in elderly people and becomes much more common as they age.

The mean blood pressure of female indicated that there was an increase in systolic and diastolic mean BP with increasing age. The mean blood pressure of males indicated an increase in mean systolic BP and an almost constant level of mean diastolic BP. According to statistics, younger men tend to have higher blood pressure than women, but as women age, their blood pressure tends to rise above that of men.^43,44

Conclusion

In conclusion, the study reported that awareness of hypertension was high, respondents in the age bracket 25-34 years reportedly had more salt intake because they patronize Western foods or processed foods, consume more alcohol, smoke more, and engage in more physical activities, while the older age groups consumed more fruits and vegetables. It is important that awareness of salt intake, alcohol intake, and smoking be propagated, especially among younger staff, in an effort to reduce the incidence of hypertension later in life. Regular health screening of KIU staff is recommended.

Ethical approval

The study was approved by Research and Ethics Committee of Kampala International University-Western Campus, Uganda, and was registered as KIU-2021-14.

A verbal Inform consent was ask from all participant before data was collected and all participant were adult not minors and those who did not approved the were not included in the research, verbal consent was used because only adult were used and the study was explain and those who gave consent were used.