23 / 52
SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
VOLUME 15 NUMBER 2 • NOVEMBER 2018
61
development and implementation of local guidelines to improve
diabetes care and minimise complications due tohypertension.
43
Possible reasons for this very low level of control may be that
the majority of people with hypertension are not aware they
have the condition, and even among those who are aware, less
than half are receiving treatment. However, even among those
receiving treatment, only one in three achieve blood pressure
control. A worrying global trend is that low levels for the control
of hypertension are widespread in both low- and high-income
countries.
7,40,44,45
There is an additional risk reduction with ACE inhibitors and
β
-blockers over and above that associated with lowering of blood
pressure among diabetics.
12
However, the use of ACE inhibitors/
ARBs among those who knew their status was in only one-third of
all participants, yet we know that ACE inhibitors reduce the risk for
nephropathy and other complications of diabetes, such as LVH. For
this reason, the JNC 7 and JNC 8 recommend that every diabetic
who has hypertension must be started on ACE inhibitors/ARBs
among other treatment options.
46
In patients with type 2 DM, hypertension is associated with
LVH.
20,21
According to the Appropriate Blood Pressure Control
in Diabetes (ABCD) trial, LVH is an independent predictor of
cardiovascular events in hypertensive patients with diabetes.
22
Hypertension is also a major risk factor for myocardial infarction
and stroke,
12,23,24
and indeed it is the leading risk factor for mortality
worldwide.
5,25-27
Therefore prevention and control of hypertension
are critical in reducing morbidity and mortality attributable to
cardiovascular diseases among diabetics.
According to the UKPDS, the incidence of clinical complications
among diabetics is significantly associated with systolic blood
pressure, except for cataract extraction. Each 10 mmHg decrease
in updated mean systolic blood pressure is associated with risk
reductions of 12% for any complication related to diabetes, 15% for
deaths related to diabetes, 11% for myocardial infarction and 13%
for microvascular complications. Any reduction in blood pressure is
likely to reduce the risk of complications, with the lowest risk being
in those with systolic blood pressure less than 120 mmHg.
12
An upcoming comprehensive review of global publications on
NCD costs from low- and middle-income countries confirms that
primary prevention of CVD, stroke and diabetes is far less expensive
and has lower unit costs than treatment interventions for these
conditions. One way to achieve this is to control hypertension.
34
The following factors were associated with hypertension among
the newly diagnosed diabetics in the bivariate model: age above
40 years, female gender, unemployment, lack of physical exercise,
overweight and obesity, increased waist:hip ratios, LVH and diastolic
dysfunction. However after adjusting for possible confounders, only
unemployment, gender and increasing BMI were independently
associated with hypertension in this model. Among these factors,
unemployment and BMI are modifiable, while gender is the non-
modifiable factor associated with hypertension.
Attaining and maintaining a healthy weight improves blood
pressure and diabetes management, and reduces cholesterol levels.
The Trials of Hypertension Prevention (TOHP) study showed that a
decrease of 4.4 kg can lead to a blood pressure reduction of 4/3
mmHg.
16
In a study to determine the prevalence and factors associated
with hypertension among residents of the rural district of
Rukungiri, Uganda, some of the factors found to be associated
with hypertension included: being overweight or obese, female
gender and older age.
37
However all these factors, apart from
obesity and being overweight, had no significance in our study in
the multivariate model. The reason could be that Wamala
et al
.
37
in the earlier study had a bigger sample size compared to ours and
enrolled community members, while our population was for newly
diagnosed diabetics.
Similar findings have been reported by Wamala and co-workers
37
and Musinguzi
et al
.
7
in other cross-sectional studies. These
observations suggest that demographic transition, urbanisation and
increasing life expectancy are major determinants of prevalence of
hypertension among diabetics.
7,47-49
In a population-based, cross-sectional survey, Baziel
et al
.
1
found
furtherevidencetoshowthatincreasingBMIandawaistcircumference
above the normal range were associated with hypertension. In the
same study, sociodemographic factors associated with hypertension
included increasing age, male gender, overweight and obesity.
With the substantial burden of hypertension in Uganda coupled
with low awareness and limited treatment of hypertension,
especially among diabetics, enhanced communitybased education
and prevention efforts tailored to addressing modifiable factors are
needed.
5
In our study, participants who were employed were 63%
less likely to have hypertension compared to their unemployed
counterparts. One possible explanation would be the lack of
physical exercise among the unemployed participants, whereas
those who are working often do manual labour in most parts of
sub-Saharan Africa.
As observed elsewhere, the prevalence of hypertension increases
with increasing age, and the increase is more marked among
women than men.
33,50
We found age above 40 years to be associated
with hypertension in the bivariate model, however this level of
significance was lost in the multivariate model. With increasing life
expectancy, the risk of hypertension becomes very important in sub-
Saharan Africa, a region undergoing an epidemiological transition.
In addition patients who had LVH and/diastolic dysfunction were
more likely to have hypertension compared to their counterparts
without these heart problems. However this was no longer
significant at multivariate level. One of the possible explanations
could be that hypertension among diabetics caused LVH and
diastolic dysfunction, as cited in the ABCD trial and other studies.
22
Therefore treating hypertension would be one way to prevent
these complications because 75% of all CVD in diabetics can be
attributed to hypertension.
Microalbuminuria was not associated with hypertension in this
study, despite the fact that it is one of the major CVD risk factors.
Okpere
et al
., in a cross-sectional study among young people in
the community, found contradictory evidence,
51
but the population
they studied was not diabetic.
Type 2 DM and hypertension share several common risk factors,
such as physical inactivity and unhealthy diet. Overweight and
obesity are potentially amenable to behavioural modification. The
benefits of prevention and care extend beyond cardiovascular
disease to related conditions of public health importance. They are
the focus of efforts to ensure greater prioritisation of NCDs on the
global research agenda as well as of development agencies and in
the health and development policies of low-income countries.
Limitations
In the diagnosis of hypertension, we did not perform ambulatory
blood pressure monitoring, which is the gold standard, according
to guidelines for the diagnosis of hypertension.
29
This was due