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JOURNAL OF SCIENCE, Hue University, N
0
61, 2010 HYPERTENSION PREVALENCE AND RELATED FACTORS
IN ELDERLY PEOPLE IN KHANH HOA PROVINCE, VIETNAM
Truong Tan Minh, Le Tan Phung et al
Khanh Hoa Provincial Health Service
SUMMARY
Hypertension is one of the major health problems among Elderly People has been
investigated by many Vietnam authors. Vietnam Institute of Health Strategy and Policy
presented a hypertension percentage of 28,4% among Elderly People of aged 60 years or above
in 2006. Based on a systemic randomized sample of Elderly People living in Khanh Hoa
Province, hypertension prevalence and related factors have been examined. Using cluster
sampling with 30 communes seleted from the total of 137 communes of the Khanh Hoa Province,
authors had chosen a sample of 2,170 Elderly People to measure blood pressure and collect
other anthropometric indeces (weight, height). Correlation and Logistic regression analysis has
been used to examine possitive association between anthropometric factors and
hypertension.Mean systolic and mean diastolic blood pressures were statistically different in
men and women Elderly People with higher percentage in Men. Mean BMI of Elderly People
was 20.26 with slightly higher in Men but no statistically significant (20.40 vs 20.17).
Hypertension prevalence in Elderly People of Khanh Hoa Province was 48.1% with higher
percentage in Men than Women (52.2% and 45.4%, respectively, p = 0,002). The Raglai
minority people who are mostly living in the 2 mountainous districts have a relatively low
percentage of hypertension (29.7%). There is an association between hypertension and BMI,
especially in Women. The survey showed that the prevalence of hypertension among Elderly
People in Khanh Hoa in 2008 was 48.1% (95% CI: 46,0% - 50,2%). There were associations

2. Methods
The study population was Elderly People (60+ years of age) who lived in Khanh
Hoa province at the time of study (from Nov to Dec 2008). A cross-sectional design was
used with cluster sampling based on 30 communes selected conveniently from 137
communes in the province. Sample size was determined by the following formula:
2
)
2
1(
2
)1(
d
pp
zn





In which: n = sample size
p = hypertension prevalence, take p = 50%.
d = desired precision, select d = 3%.
Calculated n = 1,067. Adjusted with design effect (DE=2) and 5% missing
subjects, we have the final sample size was 2,240 Elderly People. Data collected was
age, gender, ethnicity, systolic and diastolic blood pressure, height and weight.
Data were entered by EpiData Software version 3.1, analyzed by Stata version
10.0.
3. Results and discussion
3.1. Baseline data
There were a total of 2,170 Elderly People seleted for the sample because of

866
367
50
2

40.8
39.9
16.9
2.3
0.1
Ethnicity:
Kinh
Raglai
T’rin
Others

2,095
64
1
10

96.5
2.9
0.1
0.5
3.2. Anthropometric characteristics of Elderly People
3.2.1. Weight
The mean weight of the sample was 49 kg ± 8.7 kg. The mean weight of males
was significantly higher than females (Table 2).
Table 2. Mean weight of Elderly People by gender

Male (n = 849) 20.40 3.01
t
2168
= 1.683
p = 0.0926
Female (n = 1.321) 20.17 3.14
Total (n = 2.170) 20.26 3.09
According to the WHO classification of BMI (with 4 categories: underweight,
normal, overweight, and obesity), this survey showed a percentage of 30% underweight,
whereas normal BMI was 64%. The very small proportion of overweight (5.6%) and
obesity (0.3%) reflects that overweight and obesity are not a health problem among
Elderly People in Khanh Hoa province (Table 5).
Table 5. BMI classification of Elderly People by gender
Category Male Female Total Test
Underweight
239
(28.2%)
409
(31.0%)
648
(29.9%)
χ
2
= 2.7525
p = 0.431
Normal
562
(66.2%)
832
(63.0%)

2166
= 3.313
p = 0.0009
Female 1,319 135 20.9
Total 2,168 136 20.8
Diastolic blood pressure (mmHg)
Male 849 82 9.9
t
2166
= 3.989
p = 0.0001
Female 1,319 80 10.7
Total 2,168 81 10.4
3.3.2. Hypertension prevalence.
Based on definitions and classification of Blood Pressure Levels by WHO/ISH
[5], the prevalence of hypertension among Elderly People in Khanh Hoa province was
48.1% that is significantly higher than Nguyen Dang Phai’s and Dam Viet Cuong’s
surveys. Hypertension among men was statistically higher than that among women:
52.2% vs 45.4% (Table 7).
Comparing hypertension prevalence among Kinh People and Raglai People,
who are the main ethnic minority group living in Khanh Hoa Province (most of them
are in Khanh Son and Khanh Vinh district), the survey showed a higher hypertension
prevalence among Kinh People, probably related to urbanization and sedentary lifestyle
in Kinh Pepole. 292
Table 7. Hypertension by Gender and Ethnicity
Gender Total Hypertension Percent Test
Gender

293
100 150 200 250
sysBP
10.00 15.00 20.00 25.00 30.00 35.00
bmi
sysBP Fitted values

Figure 2. Association between systolic blood pressure and BMI
Analyzing associations by gender showed a stronger association in females than
males in terms of systolic blood pressure and BMI as shown in Figure 4 and a stronger
association in males than females in terms of systolic blood pressure and age as shown
in Figure 3.
100 150 200 250
60 70 80 90 100 60 70 80 90 100
female male
sysBP Fitted values
sysBP
age
Graphs by gender

Figure 3. Association between systolic blood pressure and age by Gender 294
100 150 200 250
10.00 20.00 30.00 40.0010.00 20.00 30.00 40.00
female male
sysBP Fitted values
sysBP
bmi

of the WHO, Vol 79 No 6, 2001.
3. Nguyễn Đăng Phải. Survey on hypertension and building a model of caring for Elderly
People based on Community. Report to the provincial committee of Hai Duong, on the
web http://www.haiduongdost.gov.vn dated 30/11/2009.
4. Dam Viet Cuong et al. Examine Caring for Elderly People in Vietnam – summary report
of the year 2006 on the web at http://www.hspi.org.vn/ 30/11/2009.
5. WHO/ISH writing group. 2003 World Health organization (WHO)/International Society
of Hypertension (ISH) statement on management of hypertension. “Journal of
Hypertension” Vol 21, No 11. 2003.