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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 2, March/April 2018
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AFRICA
the prevalence of DM among drivers was 17.5%, comparable
to the value obtained from this study, but higher than the 8.5%
prevalence reported by the IDF in 2014.
13
Obesity is a risk
factor for type 2 DM. From our study, BMI was a predictor of
abnormal glucose profiles, similar to the findings by Sangaletti
et al
.
12
The prevalence of dyslipidaemia in this study was 56.3%,
comparable to the national average of 60.1%.
38
The predominant
dyslipidaemia was elevated TC levels in 27.8% of the subjects,
followed by elevated LDL-C levels in 24.6%, elevated triglycerides
in 24.6% and low HDL-C levels in 6.5%. There are no local
studies of lipid abnormalities in professional drivers. The pattern
obtained is at variance however with patterns reported in
local studies in apparently healthy Nigerians, in which the
predominant dyslipidaemia was low HDL-C levels.
38
In Iran,
professional drivers have been shown to have predominantly
hypertriglyceridaemia and central obesity, attributable to
stressful working conditions.
13
The combined prevalence of overweight and obesity, measured
by BMI in this study, was 62.8%, comparable to the 63.4 and
64.4% reported by similar local studies,
19-21
but higher than
the reported prevalence of 31 to 48% in the general Nigerian
population.
39,40
Similar international studies documented a
prevalence of combined overweight and obesity to be between
62.1 and 78.2%.
13,41,42
Using waist circumference, the prevalence
of obesity from this study was 24.1%. This was lower than the
58.2 and 63.3% from studies in Brazil and Iran, respectively.
12,41
This difference might be methodological. In these countries the
cut-off for abdominal obesity is 88 cm, less than the 102 cm used
in our study.
43,44
Prolonged work stress and long hours at work
contribute to the development of obesity and abdominal obesity
in professional drivers.
13
The prevalence of physical inactivity in this study was
50.9%, comparable to the 53.4% from a local study,
20
but
lower than the 72.8% reported by similar international
studies.
12,45
Both studies were among truck drivers who
probably do not have to stop on the way for passengers to
alight for refreshments. Physical inactivity and dietary habits
of professional drivers are known to predispose to obesity.
Obesity increases the risk of hypertension and abnormal
glucose profiles, as shown in this study. It is also known to
increase the risk of road traffic accidents among professional
drivers due to its association with obstructive sleep apnoea
and excessive daytime sleepiness, consequent fatigue and
reduction in alertness while driving.
46
The prevalence of smoking in this study was 19.5%. Reported
prevalence in similar local studies is between 17.8 and 31.3%, all
higher than the 15% in the general population.
20,21,47,48
The lower
prevalence from this study might be due to dilution effect from
the ‘no smoking within the bus terminal’ policy of one of the
transport companies used in this study. Secondly, the subjects
may not have been truthful in their responses to the question on
smoking status. Comparable rates of 20 and 15.6% were reported
in similar international studies.
12,45
Alcohol consumption was very common in this study group,
with a prevalence rate of 71.1%. Reported local prevalence
in this group ranged from 34 to 84.4%.
20,48,49
These figures are
much higher than the 7.6 and 9.1% reported in the general male
population.
50,51
A recent local study from Muslim-dominated
north-west Nigeria documented a prevalence of 5.5% among
inter-city bus drivers.
21
This very low figure might be related
to a religious obligation that forbids Muslims from consuming
alcohol.
It is pertinent to note that in this study, CVD risk factors
co-occurred, as has been documented in the past.
52
This
clustering of risk factors increases the overall CVD risk of the
individual and also makes control difficult due to problems of
pill burden.
53,54
In this study 45.1% of the subjects had more
than two risk factors clustered together. Clustering of CVD risk
factors has been documented in the general population, with
prevalence rates between 12.9 and 27.5%, depending on the
study population. The commonest risk-factor combinations are
hypertension, obesity, abnormal glucose profile and atherogenic
dyslipidaemia.
55-57
Our findings are similar to the above pattern,
although the combination of hypertension and abnormal
glucose level was most prevalent. These findings are similar to
the pattern reported in similar studies.
12,13
There were some limitations in this study. The use of
glycosylated haemoglobin would have been helpful in assessing
the quality of glycaemic control among the diabetic subjects. Bus
drivers with poor control of both BP and glucose levels were not
assessed for medication adherence.
Conclusion
Long-distance professional drivers in Nigeria are at a higher
risk for CVD than the general male population on account of
the higher prevalence of a plethora of risk factors they harbour:
hypertension, abnormal glucose profiles, overweight/obesity,
alcohol use, smoking and atherogenic dyslipidaemia. These risk
factors not only co-occur in a large number of drivers, but most
are unaware of their risk. Overweight/obesity is the common
driver of hypertension and abnormal glucose profiles among
them, while age
≥
45 years increases the risk of developing
hypertension. Contributing to their risk is the social gradient of
inequality, which affects their access to healthcare and adherence
to medical intervention.
There is therefore a need to increase CVD risk awareness in
this vulnerable yet important segment of our population through
public awareness campaigns, banning of smoking and selling of
alcoholic beverages in motor parks, compulsory annual health
screening, defined maximum driving hours per week, provision
of facilities to promote physical activity in the motor parks
and medical facilities to diagnose, treat and monitor risk-factor
control. Universal health insurance coverage as a national
health policy would also help in providing healthcare/health
promotional services to this group, who at the moment are not
covered by the health insurance scheme.
The authors thank Drs Igebu, Anyakpele, Oyatokun, Eluogu and Oshuntokun
for helping out with data collection, and Chimamaka Chibuike and Joy
Alozie for their help in preparing the manuscript.
References
1.
World Health Organization. Prevention of cardiovascular disease:
Guidelines for assessment and management of cardiovascular risk,
2007. Geneva, Switzerland
.
Accessed July 22, 2015.
2.
SIGN (Scottish Intercollegiate Guidelines Network). Risk estimation
and the prevention of Cardiovascular Disease. A National Clinical