Impact of aging on cardiac function in a female rat model of menopause: role of autonomic control, inflammation, and oxidative stress

Figures & data

Table 1 Metabolic evaluations and physical capacity in YC, YO, OC, and OO groups

Parameters/groups	YC	YO	OC	OO	P-value
Body weight (g)
Initial	202.0±6.04	227.4±5.02	250.9±10.13*,#	270.0±11.07*,#	0.0001
Final	220.6±6.59‡	263.3±5.56*,‡	251.4±12.78	271.0±11.38*	0.0001
Adipose tissue (g)	3.78±0.51	6.55±0.88*	6.56±0.65*	6.27±0.65*	0.001
Triglycerides (mg/dL)	109.85±5.90	113.50±5.68	124.55±8.95*,#	130.80±5.81*,#	0.05
Glycemia (mg/dL)	88.13±1.14	84.75±0.79	83.40±5.06	84.20±7.70	0.331
Cholesterol (mg/dL)	166.13±1.44	164.13±1.23	169.00±3.64	164.29±1.55	0.389
kITT (%/min)	4.41±0.36	3.63±0.22	3.33±0.17*	3.18±0.31*	0.001
Physical capacity (km/h)	1.98±0.07	1.67±0.08*	1.35±0.05*,#	1.02±0.05*,#,¥	0.0001

Notes: Data are represented as mean ± standard error of the mean.

* P<0.05 vs YC,

¥ P<0.05 vs OC,

# P<0.05 vs YO,

‡ P<0.05 vs OO.

Abbreviations: kITT, constant decrease of plasma glucose; OC, old (24 months old) control; OO, old ovariectomized; YC, young (5 months old) control; YO, young ovariectomized.

Table 2 Echocardiographic measurements in YC, YO, OC, and OO groups

Parameters/groups	YC	YO	OC	OO	P-value
Morphometry
LVM (g/kg)	1.01±0.08	1.01±0.02	1.12±0.03*,#	1.12±0.04*,#	0.004
RWT	0.62±0.04	0.63±0.03	0.56±0.05	0.61±0.03	0.443
LVDIA (cm)	0.51±0.009	0.56±0.02	0.65±0.03*,#	0.61±0.02*	0.004
Systolic function
EF (%)	80.12±3.05	80.75±2.85	85.44±1.62	87.29±3.19	0.172
SF (%)	42.94±3.34	43.05±2.72	48.36±1.97	52.26±4.22	0.355
VCF (circ/s ×100)	0.43±0.01	0.44±0.03	0.46±0.02	0.46±0.04	0.972
Diastolic function
IVRT (ms)	28.6±0.60	27.25±1.04	40.69±4.49*,#	41.40±3.14*,#	0.01
Dec E (ms)	57.40±3.58	49.42±3.72	59.22±1.32	62.45±3.50#	0.04
E/A	2.04±0.08	2.19±0.13	1.74±0.08*,#	1.60±0.06*,#	0.001
Global function
MPI	0.25±0.03	0.26±0.03	0.43±0.05*,#	0.40±0.05*,#	0.05

Notes: Data are represented as mean ± standard error of the mean.

* P<0.05 vs YC,

# P<0.05 vs YO.

Abbreviations: Dec E, E wave deceleration time; E/A, E wave and A wave ratio; EF, ejection fraction; IVRT, isovolumetric relaxation time; LVDIA, left ventricular diameter during diastole; LVM, left ventricular mass; MPI, myocardial performance index; OC, old (24 months old) control; OO, old ovariectomized; RWT, relative wall thickness; SF, shortening fraction; VCF, velocity of circumferential fiber shortening; YC, young (5 months old) control; YO, young ovariectomized.

Table 3 Cardiac autonomic control in YC, YO, OC, and OO groups

Parameters/groups	YC	YO	OC	OO	P-value
Vagal tonus (bpm)	50.57±3.33	65.63±7.50	18.60±4.71*,#	17.14±4.21*,#	0.0001
Sympathetic tonus (bpm)	40.78±10.05	80.75±5.64*	82.10±6.77*	95.16±12.83*	0.004
Vagal effect (bpm)	87.29±8.92	80.80±8.36	34.39±5.77*,#	14.38±1.86*,#,¥	0.0001
Sympathetic effect (bpm)	23.88±4.87	53.13±9.92*	92.26±7.40*,#	83.69±7.41*,#	0.0001
Intrinsic HR (bpm)	397±6.00	379±5.09	304±7.82*,#	311±9.83*,#	0.0001
TR (bpm/mmHg)	4.13±0.24	3.38±0.27*	2.74±0.17*	2.34±0.43*,#	0.0001
BR (bpm/mmHg)	−1.47±0.08	−1.51±0.08	−1.24±0.06*,#	−0.90±0.05*,#,¥	0.0001

Notes: Data are represented as mean ± standard error of the mean.

* P<0.05 vs YC,

# P<0.05 vs YO,

¥ P<0.05 vs OC.

Abbreviations: BR, bradycardic response; HR, heart rate; OC, old (24 months old) control; OO, old ovariectomized; TR, tachycardic response; YC, young (5 months old) control; YO, young ovariectomized.

Table 4 Inflammatory and oxidative stress evaluations in YC, YO, OC, and OO groups

Parameters/groups	YC	YO	OC	OO	P-value
IL-4 (pg/mL)	6.57±0.33	6.53±0.24	7.28±0.30	7.16±0.36	0.234
IL1B (pg/mL)	59.38±6.80	70.14±12.77	57.58±4.90	52.21±3.82	0.447
IL-6 (pg/mL)	224.54±5.97	208.05±11.38	278.09±10.57*,#	253.34±7.01*,#	0.001
TNF-α (pg/mL)	52.87±2.30	57.34±2.10	68.07±3.90*,#	63.12±2.36*	0.01
Lipoperoxidation (μmol/mg protein)	0.93±0.09	1.46±0.20*	1.02±0.10	1.47±0.13*	0.01
Protein oxidation (nmol/mg protein)	6.38±0.73	6.73±0.51	7.37±0.35	8.43±0.55*	0.05
CAT (nmol/mg protein)	0.82±0.09	1.48±0.13*	0.90±0.09#	1.42±0.14*,¥	0.003
SOD (USOD/mg protein)	21.80±0.85	24.33±0.86	21.20±1.64	23.48±0.92	0.325
GPx (μmol/min/mg protein)	0.048±0.006	0.072±0.008*	0.038±0.004#	0.075±0.005*,¥	0.0001
GSH/GSSG	7.59±0.64	4.25±0.25*	5.96±0.34*,#	4.08±0.62*,¥	0.0001

Notes: Data are represented as mean ± standard error of the mean.

* P<0.05 vs YC,

# P<0.05 vs YO,

¥ P<0.05 vs OC.

Abbreviations: CAT, catalase activity; GPx, glutathione peroxidase; GSH/GSSG, glutathione redox balance; IL, interleukin; OC, old (24 months old) control; OO, old ovariectomized; SOD, superoxide dismutase; TNF, tumor necrosis factor; YC, young (5 months old) control; YO, young ovariectomized.

Figure 1 Pearson’s correlation analysis involving all studied groups: (•) represent YC and YO rats and (▪) represent OC and OO rats.

Notes: (A) Adipose tissue and IL-6 (r=0.5, P<0.009), (B) IL-6 and vagal tonus (r=−0.7, P<0.0002), (C) TNF-α and GSH/GSSG (r=−0.60, P<0.003), (D) IL-6 and MPI (r=0.65, P<0.0002), (E) sympathetic tonus and MPI (r=0.55, P<0.006), and (F) MPI and physical capacity (r=−0.55, P<0.003).
Abbreviations: GSH/GSSG, glutathione redox balance; IL, interleukin; MPI, myocardial performance index; OC, old (24 months old) control; OO, old ovariectomized; TNF, tumor necrosis factor; YC, young (5 months old) control; YO, young ovariectomized.