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SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
VOLUME 17 NUMBER 1 • JULY 2020
25
There were 37.7% inactive students, and inactivity was more
common in Shakawe senior secondary school students than those
at St Joseph’s College. Physical activity did not vary with gender in
the two schools.
The mean (SD) SBP and DBP was 118 (13.2) and 71.8 (9.5)
mmHg, respectively, and BP was significantly higher among
students in the rural school than those in the urban school (Table 1).
Overall, the prevalence of hypertension and pre-hypertension was
13.1 and 15.5%, respectively (Table 2). There were no urban–rural
differences in hypertension and pre-hypertension. Hypertension
was more prevalent among male (OR = 4.3) than female participants
(Table 3).
Discussion
In this study, conducted among adolescents in a rural and urban
setting in Botswana, a high burden of hypertension was found in
constellation with obesity, tobacco use, alcohol use, obesity and
physical inactivity. All these may track from childhood to adulthood
and are predictive of increased cardiovascular morbidity and
mortality later in adult life.
10
For a country with a high burden of
HIV/AIDS, the increase in non-communicable diseases is a challenge
to the already stretched health system.
17,18
The prevalence of all the above risk factors has been increasing
among children, mainly as a consequence of urbanisation and
change in lifestyle,
11-13
with urbanisation leading to an increase in
the use of tobacco and alcohol, poor diet and physical inactivity.
14-16
The prevalence of hypertension found in this study was within the
prevalence of 0.2 to 24.8% reported in the recent meta-analysis
of hypertension studies among African children and adolescents.
30
Although our findings are consistent with previous studies, we
recognise that comparing the prevalence of paediatric hypertension
is a challenge due to differences in the definition of hypertension, the
age groups of the studied populations and the blood measurement
methodology. Nonetheless, the burden of hypertension among our
participants was appreciably higher than the prevalence of 3 to 5%
among adolescents in the developed world.
31
We also observed a
high prevalence of pre-hypertension in our adolescents.
Table 1.
Characteristics of student participants at St Joseph’s and
Shakawe senior secondary schools (
n
= 252)
All
St Joseph’s Shakawe
Characteristics
(
n
= 252)
(
n
= 120)
(
n
= 132)
p
-value
Mean age (SD), years
17.4 ± 0.9 16.74 ± 0.74 17.49 ± 0.9 < 0.001
Age groups, years
< 18 years,
n
(%)
182 (72.2) 104 (86.7)
78 (59.1)
< 0.001
≥ 18 years,
n
(%)
70 (27.8)
16 (13.3)
54 (40.9)
Gender
Girls,
n
(%)
172 ( 68.3) 83 (69.2)
89 (67.4)
0.767
Boys,
n
(%)
80 (31.7)
37 (30.8)
43 (32.6)
Height, mean (SD), cm 164.9 ± 8 163.42 ± 7.8 166.19 ± 8
0.006
Mean WC (SD), cm
69.3 ± 7.1 68.00 ± 7.8 70.49 ± 6.3 0.006
Mean weight (SD) kg
55.6 ± 9.9 55.3 ± 11.4 55.88 ± 8.7 0.670
Mean HC (SD), cm
91.3 ± 9.5 90.45 ± 11.2
92.0 ±7.5
0.208
Mean FBG (SD), mmol/l 4.70 ± 0.5 4.70 ± 0.44 4.71 ± 0.47 0.788
Mean SBP (SD), mmHg 118 ± 13.2 112.39 ± 12.6 122.62 ± 12.7 < 0.001
Mean DBP (SD ), mmHg 71.8 ± 9.5 68.5 ± 9.5 74.8 ± 8.4 < 0.001
Mean pulse (SD), bpm 80.3 ± 13.3 79.1 ± 11.7 81.4 ± 14.6 0.164
Family history of HPT,
n
(%)
75 (29.8)
42 (35)
33 (25)
0.083
Family history of
DM,
n
(%)
15 (6)
10 (8.3)
5 (3.8)
0.128
Family history of
stroke,
n
(%)
16 (6.3)
2 (1.7)
16 (10.6)
0.004
HPT: hypertension; DM: diabetes mellitus; FBG: fasting blood glucose; WC:
waist circumference; HC: hip circumference; BMI: body mass index; SBP;
systolic blood pressure; DBP: diastolic blood pressure; bpm: beats per minute,
SD: standard deviation.
Table 2.
Table showing the distribution of cardiovascular risk factors among students at St Joseph’s and Shakawe senior secondary schools (
n
= 252)
School
Gender
All
St Joseph’s
Shakawe
Female
Male
Parameters
(
n
= 252)
(
n
= 120)
(
n
= 132)
p
-value
(
n
= 172)
(
n
= 80)
p
-value
Hypertension,
n
(%)
Normal
180 (71.4)
89 (74.2)
91 (68.9)
0.380
138 (80.2)
42 (52.5)
< 0.001
PreHPT
39 (15.5)
19 (15.8)
20 (15.2)
20 (11.6)
19 (23.8)
Hypertension
33 (13.1)
12 (10)
21 (15.9)
14 (8.1)
19 ( 23.8)
Overweight or obesity,
n
(%)
Underweight
25 (9.9)
11 (9.2)
14 (10.6)
0.536
9 (5.2)
16 (20)
< 0.001
Normal weight
201 (79.8)
94 (78.3)
107 (81.1)
141 ( 82)
60 (75)
Overweight/obese
26 (10.3)
15 (12.5)
11 (8.3)
22 (12.8)
4 (5.0)
WC, cm
Normal
229 (90.9)
108 (90)
121 (91.7)
0.109
162 (94.2)
77 (96.3)
0.491
Increased
23 (9.1)
12 (10)
11 (8.3)
10 (5.8)
3 (3.8)
Fasting blood glucose, mmol/l
Normal
248 (98.4)
118 (98.3)
130 (98.5)
0.923
168 (97.7)
80 (100)
0.169
IFG
4 (1.6)
2 (1.7)
2 (1.5)
4 (2.3)
0 (0.00)
Level of physical activity,
n
(%)
Inactive
95 (37.7)
32 (26.7)
63 (47.7)
0.002
70 (40.7)
25 (31.3)
0.164
Minimal
76 (30.2)
45 (37.5)
31 (23.5)
53 (30.8)
23 (28.8)
Highly active
81 (32.1)
43 (35.8)
38 (28.8)
49 (28.5)
32 (40)
Smoking,
n
(%)
5 (2)
3 (2.5)
2 (1.5)
0.567
1 (0.6)
4 (5.0)
0.019
Alcohol intake,
n
(%)
23 (9.1)
17 (14.2)
6 (4.5)
0.008
14 (8.1)
9 (11.3)
0.425
PreHPT: pre-hypertension; HPT: hypertension; BMI: body mass index; WC: waist circumference; IFG: impaired fasting glucose.