SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
VOLUME 15 NUMBER 2 • NOVEMBER 2018
67
had grade 2 pattern of DD. None of the microalbuminuric group
had grade 3 but 3.2% of the normoalbuminuric group did. These
observed differences were statistically significantly different (
χ
2
=
50.05,
p
< 0.01).
Table 3 shows clinical and biochemical parameters that correlated
significantly with indices of LV diastolic function (E/A ratio and IVRT)
among the normotensive diabetics. The strongest correlate of E/A
ratio in the model was age (
p
< 0.001). Serum creatinine level (
p
=
0.009) and eGFR (
p
= 0.009) also correlated significantly with E/A,
but the other parameters did not.
Table 4 shows univariate and multivariate regression models used
to determine predictors of LVDD in the normotensive diabetics. At
the univariate level, age andMCA statuswere significantly associated
with the occurrence of LVDD. Those with microalbuminuria had
about a four-fold increased risk of developing LVDD compared to
those with normoalbuminuria (95% CI: 1.99–6.82,
p
< 0.001).
Also, for every one year increase in age, the risk of developing DD
increased by 11% (95% CI: 4–17%,
p
≤ 0.001).
After adjusting for all the other factors in the multivariate model,
only age remained an independent predictor of DD. The model
shows that for every one year increase in age, there was a 10%
increased risk of developing DD (OR = 1.10, 95% CI: 1.03–1.17,
p
= 0.003). The area under the receiver operating curve of this
model was 0.76, suggesting a good model.
Discussion
In this study, LVDD occurred significantly more frequently in the
diabetic groups with or without MCA compared with the controls
(
p
< 0.001) and the prevalence of LVDD in both diabetic groups
were within the range of 40 to 75% reported by studies done on
normotensive diabetics within
16
and outside the country.
17
Grade 1 LVDD was the commonest, which was significantly
more in the microalbuminuric than the normoalbuminuric group
and was the only grade seen in the controls (
p
< 0.01). Aigbe
et al
.
16
and Patil
et al
.
17
reported similar findings. Higher grades
(2 and 3), although rare, were commoner in the microalbuminuric
(8.5%) than the normoalbuminuric group (6.4%).
Lower rates of LVDD were reported by Liu
et al
.
18
among
American Indians with T2DM, 16% in normo-, 26% in micro- and
31% in the macroalbuminuric groups, because diastolic function
assessment was based on only transmitral flow parameters, with
no distinctions made between normal and grade 2 DD. Therefore,
patients with a pseudo-normalised pattern were not included in
their analysis.
Systolic dysfunction was rare among the normotensive T2DM
patients, which is similar to a previous report.
3
A higher value
of 15.56% reported by Dodiyi-Manuel
et al
.
5
may be due to the
higher EF cut-off value of 55% used to define systolic dysfunction,
thus suggesting that systolic dysfunction detected by conventional
echocardiography is not an early feature of DMCMP. This supports
the assumption that alteration of both relaxation and filling usually
precede marked changes in chamber systolic function, although
more sophisticated imaging technology such as speckle-tracking
imaging (STI), used to assess myocardial strain and strain rate,
have permitted the detection of subtle systolic dysfunction in the
diabetic myocardium.
19
The significant correlation of E/A ratio with age (
p
< 0.001),
creatinine level (
p
=0.009) and eGFR (
p
=0.008) in the normotensive
T2DM patient suggests a worsening of LVDD as the patient grows
older and serum creatinine level rises as a result of decline in renal
function. Danbauchi
et al
.
20
reported a significant correlation of
LVDD with age, fasting blood glucose and two-hour postprandial
glucose level in T2DM patients. Likewise, Yazici
et al
.
21
in their
study on 76 T2DM patients of Turkish origin documented that
E/A ratio correlated significantly with age, glycated haemoglobin
(HbA
1c
) level and duration of diabetes. These observations suggest
that aging and impairment of renal function correlate with LVDD
in normotensive diabetics.
The relationship between microalbuminuria and asymptomatic
LVDD in T2DM patients has been a subject of much debate. In
this study, a worsening of diastolic function as evidenced by
significantly higher A velocity, lower E velocity and E/A ratio,
larger left atrial dimension and longer IVRT were observed in
the microalbuminuric compared to normoalbuminuric group.
Baykan
et al
.
22
also reported significantly longer deceleration time
Table 3.
Correlation coefficient of clinical and biochemical variables
compared with E/A ratio and IVRT in normotensive diabetic subjects
(
p
< 0.05)
E/A ratio
IVRT
Parameters
Rho
p
-value
Rho
p
-value
Age (years)
–0.45
< 0.001
0.06
0.55
DM duration (years)
–0.06
0.51
0.14
0.15
Weight (kg)
0.11
0.24
0.08
0.39
Body surface area (m
2
)
0.13
0.16
0.09
0.34
Body mass index (kg/m
2
)
0.06
0.49
–0.03
0.77
Waist circumference (cm)
–0.03
0.77
0.15
0.12
Hip circumference (cm)
0.004
0.97
0.06
0.55
Waist:hip ratio
–0.09
0.35
0.05
0.61
Systolic BP (mmHg)
–0.04
0.65
–0.01
0.91
Diastolic BP (mmHg)
0.14
0.15
–0.06
0.53
Pulse pressure
–0.14
0.12
0.02
0.86
Pulse rate (beat/min)
–0.11
0.22
–0.26
0.005
Creatinine (mg/dl)
–0.32
0.009
0.19
0.13
eGFR (ml/min)
0.33
0.008
–0.09
0.47
Total cholesterol (mmol/l)
–0.16
0.25
–0.13
0.36
Trigylcerides (mmol/l)
0.01
0.91
0.32
0.01
HDL-C (mmol/l)
0.02
0.87
–0.08
0.57
LDL-C (mmol/l)
–0.07
0.60
–0.04
0.76
Rho: correlation coefficient, DM: diabetes mellitus, eGFR: estimated
glomerular filtration rate, HDL-C: high-density lipoprotein cholesterol, LD-C:
low density lipoprotein cholesterol.
Table 4.
Logistic regression model to determine predictors of left
ventricular diastolic dysfunction in the normotensive diabetic subjects
Univariate analysis
Multivariate analysis
Odds ratio
Odds ratio
Variable
(95% CI)
p
-value
(95% CI)
p
-value
Age
1.11 (1.04–1.17) < 0.001* 1.10 (1.03–1.17) 0.003*
Microalbuminuria 3.58 (1.99–6.82) < 0.001* 1.81 (0.70–4.68) 0.222
Gender
0.69 (0.31–1.55)
0.309 0.56 (0.21–1.48) 0.240
BMI
0.98 (0.90–1.07)
0.719 0.91 (0.79–1.06) 0.227
Waist
1.01 (0.98–1.06)
0.452 1.04 (0.97–1.12) 0.263
DM duration
1.10 (0.96–1.24)
0.142 1.04 (0.90–1.19) 0.599
Systolic BP
1.01 (0.95–1.05)
0.824 0.98 (0.91–1.06) 0.694
Diastolic BP
0.96 (0.89–1.03)
0.234 0.97 (0.87–1.08) 0.598
Receiver operating curve 0.76, CI: confidence interval, DM: diabetes mellitus,
BP: blood pressure.