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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.