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between the two ethnic groups could have induced bias and may
have influenced the resulting differences found in the levels of
inflammatory markers.
Another consideration in the interpretation of the results is
the age of the women in this study, as they were relatively young
(
mean age 31.3 years). Although their inflammatorymarkers were
elevated due to obesity, it is likely that established atherosclerosis
and vascular dysfunction (and related inflammatory conditions)
were non-existent in this group.
32
Other results from this review also suggest an association
of obesity with a premature increase in blood pressure. A
considerable number of obese young adults in the study by
Ibhazehiebo
et al
.
36
were hypertensive compared with the
non-obese control group. Marked increases in SBP were also
observed in the obese individuals compared to the controls at
all levels of graded exercise, with the highest values seen during
extreme exercise. These findings suggest that obese young
individuals were prone to early onset of hypertension, a situation
that makes them susceptible to cardiovascular complications and
other health problems in the future.
The findings of Ibhazehiebo
et al
.
36
were also consistent
with several other studies that associated increased BMI with
increased risk of hypertension. The study by Wolf
et al
.
88
found
that the risk of hypertension was up to five times higher among
obese people than in their normal-weight counterparts.
88
Obesity
was also positively associated with type 2 diabetes,
6,89,90
and it
was noted that nearly 90% of individuals who progressed to
type 2 diabetes had BMIs above 23.0 kg/m². The compelling
association between obesity, hypertension and diabetes among
populations of African descent has also been documented.
91-93
Asfaw’s comparison of the prevalence of diagnosed chronic
diseases between obese and non-obese subjects also provides
an indication of the effect of obesity on the prevalence of
chronic diseases.
2
Each chronic disease included in the study
was more prevalent in obese respondents than in their non-obese
counterparts. In both countries (South Africa and Senegal),
the results indicated that obese subjects were more likely
to be diagnosed with two or more chronic diseases than
their lean counterparts.
2
Asfaw’s findings are congruent with
numerous studies conducted in both developed and low-income
countries.
14,94-97
Limitations
As with many other reviews, this study has a number of
limitations, hence the need to apply caution in the interpretation
of its findings. Despite the fact that this review sought to
incorporate studies from all African countries, all the studies
retrieved were articles published in English and from English-
speaking countries, reflecting a language bias. It is noteworthy
that most studies from African countries are likely to be
published in non-indexed and non-English journals.
98
Moreover,
the multilingual, multicultural, multi-ethnic and racial divides
that characterise the African continent make it difficult to
generalise the findings of this study.
A further limitation was the limited number of studies
that fitted the inclusion criteria. Initially, the protocol for this
systematic review was designed to evaluate the impact of obesity
on the health of participants on the African continent, focusing
mainly on ramdomised, controlled trials (RCTs). However, due
to the paucity of RCTs, the reviewers settled for comparative
studies. This resulted in the omission of some key articles
reporting on the extent of the obesity epidemic in Africa.
99,100
Although the comparative aspect of this review is unusual
and it resulted in variable data, it did allow us to touch on a
broader spectrum of the effects of obesity (from epidemiological
to clinical) in Africa. This would not have been feasible if purely
epidemiological studies had been included.
Also, the inclusion of three non-population based studies
from the same author
32,35,37
posed a limitation on the interpretation
of the findings in this review. Although the articles met the
inclusion criteria of comparative studies, conducting such studies
with a larger sample size would have provided more insight into
the differences observed in these groups. This highlights the
need for larger and more numerous studies of this kind.
Finally, due to the limited number of articles that met the
inclusion criteria, as well as the considerable heterogeneity, it is
difficult to justify these data as being an accurate representation
for the whole of Africa. Hence the need for more specific and
structured research on obesity on the African continent.
Conclusion
The key findings of this review are: (1) obesity was more
prevalent in urban than rural areas, particularly in women; (2)
obesity was more prevalent in Africans who migrated to Western
countries than in their counterparts on the African continent; (3)
there was a co-relationship between obesity and chronic disease.
However, inflammatory marker levels differed between black
and Caucasian individuals and therefore should not necessarily
be compared between ethnic groups.
These findings have important public health implications and
call for immediate action to combat the increasing prevalence of
obesity. This may require a policy shift towards organised and
co-ordinated strategies geared at both prevention and treatment
of existing obesity.
Provision of facilities that promote physical activities within
communities, residential areas and workplaces is essential.
Moreover, negative social pressures, cultural perceptions associ-
ated with obesity such as ‘fat is beautiful or prosperous’ should
be dispelled through educational programmes.
33
Creation of
awareness on individual and community levels of the associ-
ated health risks of obesity, augmented by population-based
health-promotion programmes are needed. These will highlight
the importance of physical activity and healthy eating habits,
which will constitute an integral part of forestalling the obesity
epidemic and managing its sequelae where it already exists.
Uncurbed, the direct and indirect burden of obesity will be
a severe challenge to the future development of Africa as a
continent, as well as other developing countries. Neglecting to
immediately deal with the problem of obesity and leaving it
unchecked will impose additional burdens on the economy and
health sector of the African continent, as well as threaten its
future development.
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