Left ventricular diastolic dysfunction in a model of obesity induced by a high carbohydrate diet
Authors: Alves Pedro Henrique Rizzi , Hasimoto Fabiana , Kitawara Koody , Fransciqueti Fabiane , Ferron Artur , Bazan Silméia , Campos Dijon , Ferreira Ana Lúcia , Corrêa Camila 
Published: November 2023

Aim

Evaluate the effect of diet obesity‐induced rich CHO on left ventricular diastolic function.

Methods

16 male Wistar rats were assigned to receive water plus standard diet (group C, n = 8) and Ob diet with water plus 25% sucrose (Ob group, n = 8). Weekly body weight (BW) of the animals was assessed and, after 30 weeks of experiment, adiposity índex (AI). The following cardiac structures were measured: diastolic diameter (LVDD) and systolic (LVSD) LV; diastolic and systolic thickness posterior wall of the left ventricle (LVPWD; LVPWS) and interventricular septum (LVISD; LVISS); diameter of the aorta (DA), left atrium (LA) and the ratio (DA/LA); The relative thickness of the LV (ERVE); LV mass (LVM); MVE index (LVMI) was calculated by normalizing to body weight estimated LV mass. The LV systolic function was assessed by percentage of endocardial shortening (Δ% endo); The LV diastolic function was evaluated by the following indices: peak velocity of early diastolic filling (E wave); peak velocity of late diastolic filling (A wave); ratio between the E and A waves (E/A); deceleration time of E wave (DTE); isovolumetric relaxation time in absolute values (IRT) and normalized for heart rate (IRTn = IRT/R‐R 0,5). The study was supplemented by evaluation by tissue Doppler early diastolic (E′) and late (A′) of the mitral annulus (arithmetic average travel speeds of lateral and septal walls), and the ratio the waves (E/E′ and E′/A′).

Results

The ob group showed significantly higher weight (C = 493,008 ± 50,775, Ob = 562,95 ± 53,69; p < 0,05) and also higher adiposity index (C = 4.79 ± 0.73, Ob = 8.68 ± 1.76; p < 0,05). Results of the cardiac evaluation at 30 weeks are described in Table 1.

Conclusion

Consumption of carbohydrate‐rich diets promotes left ventricular diastolic dysfunction associated with obesity at 30 weeks.

Results of the cardiac evaluation performed at the end of 30 weeks.

GRUPS

Variables
C
Ob
P

BW (g)
493.008 ± 50.775
562.95 ± 53.69
0.018

LVDD (mm)
7.206 ± 0.201
6.705 ± 0.560
0.031

LVSD (mm)
3.116 ± 0.190
3.163 ± 0.431
0.785

LVPWD (mm)
1.626 ± 0.190
1.723 ± 0.226
0.373

LVPWS (mm)
3.039 ± 0.314
3.355 ± 0.213
0.033

LVISD(mm)
1.659 ± 0.194
1.864 ± 0.308
0.133

LVISS (mm)
3.355 ± 0.213
3.578 ± 0.193
0.045

DA (mm)
3.736 ± 0.129
3.993 ± 0.135
0.001

LA (mm)
4.756 ± 0.129
5.173 ± 0.383
0.011

LA/DA
1.274 ± 0.059
1.297 ± 0.107
0.609

LVDD/BW
14.755 ± 1.604
11.989 ± 1.304
0.002

LA/BW
9.740 ± 1.087
9.243 ± 0.897
0.335

LVM
0.817 ± 0.150
0.823 ± 0.152
0.937

LVMI
1.669 ± 0.318
1.475 ± 0.312
0.240

ERVE
0.451 ± 0.050
0.519 ± 0.095
0.098

CF (bpm)
234.875 ± 39.364
295.500 ± 26.966
0.002

Cardiac Output
81.181 ± 18.120
81.834 ± 28.74
0.957

% endo
56.743 ± 2.615
52.397 ± 8.591
0.190

E wave
68.350 ± 5.258
73.138 ± 3.312
0.046

A wave
40.675 ± 3.656
45.725 ± 6.040
0.062

E/A
1.684 ± 0.088
1.617 ± 0.163
0.327

IRT‐ms
21.125 ± 2.232
23.250 ± 3.012
0.131

DTE‐ms
47.250 ± 3.059
50.625 ± 2.722
0.035

R‐R (seg)
0.261 ± 0.042
0.205 ± 0.019
0.003

IRT/R‐R
41.696 ± 5.773
51.420 ± 5.826
0.004

Ejection fraction
0.918 ± 0.015
0.883 ± 0.063
0.142

E′ lateral
5.588 ± 0.412
5.225 ± 0.776
0.262

A′ lateral
3.550 ± 0.493
4.050 ± 0.578
0.083

E′ septal
5.850 ± 0.404
5.788 ± 0.906
0.861

A′ septal
3.950 ± 0.946
4.863 ± 0.691
0.044

E′
5.791 ± 0.383
5.506 ± 0.735
0.479

A′
3.750 ± 0.410
4.456 ± 0.540
0.010

E/E′
12.016 ± 1.397
13.492 ± 1.867
0.093

E′/A′
1.535 ± 0.145
1.260 ± 0.253
0.018