Cardiovascular Journal of Africa: Vol 30 No 6 (November/December 2019)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 6, November/December 2019 AFRICA 365
lower when compared to a study by Day et al.,47 which reported
a 40% prevalence of hypertension among adults in South
African provinces during 2010. Peer et al.48 also reported a lower
prevalence of hypertension (38.9%) among black urban South
African adults between the ages of 24 and 65 years in Cape Town.
The study showed that women (27%) had a higher prevalence of
hypertension compared to males (22%). This is lower than the
study by Ntuli et al.49 in adults in a rural community of Dikgale
in the Limpopo Province, which showed that 42% of males and
41% of females were hypertensive.
The findings of our study are also similar to those of the
South Africa Demographic and Health Survey (SADHS),50
which reported that using a cut-off of 140/90 mmHg and gender
adjustment, 25% of men and 26% of women had hypertension.
Based on BMI categories, our study showed that obese groups
(35%) had a high prevalence of hypertension when compared to
the normal (18%) and overweight groups (22%). These findings
are similar to a study by Dua et al.,51 which found that the
prevalence of high BP was greater in those with high BMI. This
has also been reported in other studies. 52,53 The WHO4 reported
that hypertension was globally responsible for 45% of deaths
due to cardiovascular disease and 51% of deaths due to stroke.
Table 3. Participants’ anthropometric and physiological
characteristics according to BMI categories by gender
Men Women
Variables n Mean SD
p-value
of the
differences n Mean SD
p-value
of the
differences
Height (cm)
Underweight 15 169.73 9.94 0.05 1 169.00 . 0.18
Normal 123 170.71 7.19 55 161.76 9.27
Overweight 49 170.22 7.38 72 160.01 6.26
Obese 35 165.60 17.34 118 159.46 7.31
Total 222 169.73 9.81 246 160.18 7.55
Body weight (kg)
Underweight 15 49.51 5.77 < 0.001 1 51.00 . < 0.001
Normal 123 66.75 7.93 55 60.75 6.38
Overweight 49 81.50 7.68 72 73.38 5.93
Obese 35 95.09 14.77 118 92.19 14.63
Total 222 73.31 15.35 246 79.49 17.09
BMI (kg/m2 )
Underweight 15 17.17 1.23 < 0.001 1 17.85 . < 0.001
Normal 123 22.89 2.13 55 23.23 1.84
Overweight 49 28.09 1.42 72 28.65 1.46
Obese 35 34.97 5.07 118 36.20 4.87
Total 222 25.55 5.58 246 31.01 6.45
WC (cm)
Underweight 15 73.47 4.56 < 0.001 1 79.00 . < 0.001
Normal 123 85.24 12.30 55 81.85 6.92
Overweight 49 96.53 7.13 72 92.15 12.39
Obese 35 105.81 15.70 118 105.31 14.08
Total 222 90.18 14.63 246 96.11 15.56
SBP (mmHg)
Underweight 15 138.80 27.28 0.65 1 156.00 . < 0.001
Normal 123 142.20 23.05 55 130.31 21.17
Overweight 49 138.45 18.07 72 137.25 23.98
Obese 35 138.23 21.06 118 147.99 24.52
Total 222 140.52 21.98 246 140.93 24.63
DBP (mmHg)
Underweight 15 83.27 15.13 0.44 1 92.00 . < 0.001
Normal 123 78.05 14.53 55 74.80 11.11
Overweight 49 80.67 10.96 72 78.30 11.43
Obese 35 79.57 10.49 118 86.48 12.63
Total 222 79.22 13.29 246 81.50 12.91
WHtR
Underweight 15 0.43 0.02 < 0.001 1 0.46 . < 0.001
Normal 123 0.50 0.08 55 0.50 0.05
Overweight 49 0.56 0.04 72 0.57 0.07
Obese 35 0.62 0.07 118 0.65 0.08
Total 222 0.53 0.08 246 0.60 0.09
BMI = body mass index, WC = waist circumference. SBP = systolic blood pressure,
DBP = diastolic blood pressure, WHtR= waist-to-height ratio, n = number, SD = stan-
dard deviation.
Table 4. Descriptive statistics of age, height, BMI,WC, SBP, DBP and
WHtR for the overweight and obese group by gender
Variables n Min Max Mean SD F p-value
Age, years
Men 108 25.0 65.0 51.84 8.60 1.096 0.30
Women 201 24.0 65.0 52.95 9.07
Height, cm
Men 108 107.0 189.0 168.34 11.90 68.607 < 0.001
Women 201 135.0 182.0 159.46 6.94
Weight, kg
Men 108 55 132 83.97 13.43 0.009 0.93
Women 201 51 172 83.80 15.67
BMI, kg/m2
Men 108 25.10 55.11 29.76 4.81 24.941 < 0.001
Women 201 25.09 64.06 32.91 5.52
WC, cm
Men 108 70 170 98.06 11.96 0.645 0.42
Women 201 37 152 99.41 15.04
SBP, mmHg
Men 108 91.0 193.0 140.44 20.21 1.308 0.25
Women 201 86.0 229.0 143.61 24.61
DBP, mmHg
Men 108 54.0 115.0 80.23 11.12 3.041 0.08
Women 201 54.0 141.0 82.79 12.93
WHtR
Men 108 0.42 0.91 0.5786 0.06 18.969 < 0.001
Women 201 0.23 0.94 0.6215 0.09
BMI = body mass index, WC = waist circumference. SBP = systolic blood pres-
sure, DBP = diastolic blood pressure, WHtR= waist-to-height ratio, n = number,
SD = standard deviation.
Table 5. Correlation coefficients (r) for normal, overweight and obese groups
Groups BW, r BMI, r WC, r SBP, r DBP, r WHtR, r
Normal
BW (kg) – 0.51** 0.50** 0.05 –0.02 0.09
BMI 0.51** – 0.42** 0.15* 0.004 0.52**
WC 0.50** 0.42** – 0.26** 0.11 0.82**
WHtR 0.09 0.52** 0.82** 0.29** 0.14 –
Overweight
BW (kg) – 0.22* 0.51** 0.01 0.08 –0.09
BMI 0.22* – 0.23* 0.17 0.23* 0.44**
WC 0.51** 0.23* – 0.23* 0.18 0.71**
WHtR –0.09 0.44** 0.71** 0.26** 0.19* –
Obese group
BW (kg) – 0.57** 0.59** 0.02 0.09 0.19*
BMI 0.57** - 0.47** 0.04 0.11 0.57**
WC 0.59** 0.47** – 0.15 0.07 0.78**
WHtR 0.19* 0.57** 0.78** 0.14 0.08 –
**Correlation is significant at the 0.01 level (2-tailed).
*Correlation is significant at the 0.05 level (2-tailed).
BW = body weight, BMI = body mass index, WC = waist circumference, SBP =
systolic blood pressure, DBP = diastolic blood pressure, WHtR = waist-to-height
ratio.