The SA Journal Diabetes & Vascular Disease Vol 15 No 1 (July 2018)

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RESEARCH ARTICLE SA JOURNAL OF DIABETES & VASCULAR DISEASE
26 VOLUME 15 NUMBER 1 • JULY 2018
Table 5. Correlation analysis of LA volume and function with
2D echocardiographic parameters and laboratory findings
Indexed Indexed Indexed Indexed Indexed Indexed
Vmax Volp Vmin PEV AEV TEV
(ml/m²) (ml/m²) (ml/m²) (ml/m²) (ml/m²) (ml/m²)
Glucose (mg/dl) r 0.153 0.252 0.182 –0.034 0.204 0.075
P 0.108 0.007 0.055 0.725 0.031 0.429
HbA1c (%) r 0.288 0.367 0.294 0.006 0.301 0.192
P 0.002 < 0.001 0.002 0.954 0.001 0.043
BMI (kg/m2) r 0.430 0.441 0.368 0.135 0.340 0.325
P < 0.001 < 0.001 < 0.001 0.154 < 0.001 < 0.001
TG (mg/dl) r 0.152 0.248 0.136 –0.047 0.239 0.089
p 0.110 0.008 0.153 0.625 0.011 0.350
hsCRP (mg/l) r 0.412 0.420 0.320 0.103 0.371 0.308
p < 0.001 < 0.001 0.001 0.281 < 0.001 0.001
Uric acid r 0.362 0.378 0.297 0.125 0.283 0.253
(mg/dl) p < 0.001 < 0.001 0.001 0.190 0.002 0.007
Mitral A (cm/s) r 0.328 0.380 0.292 –0.002 0.321 0.232
p < 0.001 < 0.001 0.002 0.981 0.001 0.014
Mitral E’ (cm/s) r –0.274 –0.258 –0.211 –0.094 –0.202 –0.226
p 0.003 0.006 0.026 0.323 0.033 0.017
Mitral A’ (cm/s) r 0.278 0.281 0.310 0.064 0.117 0.138
p 0.003 0.003 0.001 0.504 0.220 0.147
E/E’ ratio (cm/s) r 0.279 0.286 0.255 0.059 0.197 0.192
p 0.003 0.002 0.007 0.539 0.037 0.028
E/A ratio (cm/s) r 0.085 0.129 0.288 –0.050 –0.135 –0.140
p 0.374 0.177 0.002 0.604 0.154 0.142
p 0.003 0.006 0.026 0.323 0.033 0.017
Mitral A’ (cm/s) r 0.278 0.281 0.310 0.064 0.117 0.138
p 0.003 0.003 0.001 0.504 0.220 0.147
E/E’ ratio (cm/s) r 0.279 0.286 0.255 0.059 0.197 0.192
p 0.003 0.002 0.007 0.539 0.037 0.028
E/A ratio (cm/s) r 0.085 0.129 0.288 –0.050 –0.135 –0.140
p 0.374 0.177 0.002 0.604 0.154 0.142
LA: left atrium, BMI: body mass index, TG: triglycerides, hsCRP: high-sensitivity
C-reactive protein, PEV: passive emptying volume, AEV: active emptying
volume, TEV: total emptying volume.
Recent studies have shown that LA enlargement, obtained
from 2D echocardiography, is a good predictor of cardiovascular
outcomes.7 However, there are several limitations to estimating
LA size because of the irregular geometry of the left atrium.
Additionally, the left atrium often enlarges asymmetrically, which
causes underestimation of its size. Therefore, it has been suggested
that LA volume may be a superior measure of LA size.7 Moreover,
changes in LA volume are increasingly becoming a parameter of
interest as a marker of overall cardiac function.
Several studies have shown that changes in LA size and
mechanical function may be associated with adverse clinical events
such as atrial fibrillation, stroke, diastolic dysfunction and LV failure,
both in the general and the diabetic population.6,8,10-14,19,20
Moreover, it has been reported that indexed V ≥ 32 ml/m2
predicts cardiovascular mortality and morbidity independently of
myocardial perfusion sintigraphy-detected myocardial ischaemia
with a six-year follow-up period. 21
Cardiovascular imaging modalities for the determination of LA
function, such as computed tomography (CT), CMRI, 2D and 3D
echocardiography, are evolving. Although the main advantage of
CMRI and CT over echocardiography is the determination of all
parts of the left atrium, including the LA appendage, the use of
iodine and radiation during CT and the usefulness of CMRI in
patients with pacemakers limit their usage.7 Therefore, we preferred
to use 2D echocardiography, which is a non-invasive, easy-to-
use and accessible method to evaluate LA volume and function.
Moreover, similar to our findings, the mean indexed V value was
23.6 ± 5.8 ml/m2 in max a newly diagnosed diabetes group in the
study population of Zoppini.14
The incidence of diastolic dysfunction in patients with DM2 is
reported to be 43 to 75%.4 Recent evidence suggests that LA
dilatation and dysfunction may be a co-existing marker of diastolic
dysfunction in patients with DM2.4 However, Kadappu et al.
demonstrated LA dilatation may be present in patients with DM2
independent of diastolic dysfunction and associated hypertension.4
Recently, another study by Zoppini et al. reported that diabetes
itself might cause LA enlargement.14 These findings suggest that
co-existing diabetic atrial cardiomyopathy may independently alter
the LA size and function.4,14
In our study, 51.8% of the diabetic patients had some degree
of diastolic dysfunction with no difference regarding LA volume
and function, compared with the diabetic patients without diastolic
dysfunction. This finding and a weak correlation between 2D
echocardiographic diastolic parameters and LA volume in our
Table 6. Univariate and multivariate analysis for predictors of LA volume and function of the study population
Univariate analysis Multivariate analysis
Parameters DM2 HT HL Age BMI hsCRP Uric acid DM HT HL Age BMI hsCRP Uric acid
LA diameter (mm) < 0.001 < 0.001 0.0281 < 0.001 < 0.001 0.003 0.001 0.227 0.001 0.005 0.002 < 0.001 0.879 0.194
Indexed Vmax (ml/m²) < 0.001 < 0.001 0.003 < 0.001 < 0.001 < 0.001 < 0.001 0.438 0.056 0.100 0.001 0.004 0.191 0.064
Indexed Volp (ml/m²) < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 0.991 0.181 0.244 0.003 0.016 0.226 0.042
Indexed Vmin (ml/m²) < 0.001 < 0.001 0.007 < 0.001 < 0.001 0.001 0.001 0.869 0.171 0.334 0.069 0.099 0.371 0.034
Indexed PEV (ml/m²) 0.66 0.268 0.971 0.171 0.164 0.281 0.190 – – – – – – –
Indexed AEV (ml/m²) < 0.001 < 0.001 0.001 0.001 < 0.001 < 0.001 0.002 0.822 0.623 0.476 0.010 0.064 0.383 0.486
Indexed TEV (ml/m²) 0.004 0.001 0.051 < 0.001 < 0.001 0.001 0.007 0.189 0.259 – 0.003 0.020 0.443 0.418
LA passive emptying
fraction (%) 0.003 0.052 0.011 0.169 0.044 0.065 0.338 0.150 – 0.438 – 0.897 – –
LA active emptying
fraction (%) 0.386 0.769 0.499 0.393 0.718 0.430 0.968 – – – – – – –
LA total emptying
fraction (%) 0.05 0.117 0.162 0.293 0.148 0.395 0.363 – – – – – – –
DM: diabetes mellitus, HT: hypertension, HL: hyperlipidaemia, BMI: body mass index, hsCRP: high-sensitivity C-reactive protein, LA: left atrium, PEV: passive
emptying volume, AEV: active emptying volume, TEV: total emptying volume.