Obesity-Induced Heart Rate Variability Impairment and Decreased Systolic Function in Obese Male Dogs

Abstract

Obesity can induce cardiovascular diseases in both humans and animals. Heart rate variability (HRV) is an indicator of sympathovagal balance and is used to identify cardiovascular diseases in humans. However, HRV and cardiac function have rarely been investigated in obese dogs. This study investigated the effect of obesity on oxidative stress, HRV, and cardiac function in obese and non-obese dogs. The nine-scale body condition score (BCS) system was used to determine obesity. Thirty small breed dogs were divided into a normal weight group (n = 15) and an obese group (n = 15). All dogs underwent physical examination, plasma malondialdehyde (MDA) measurement, electrocardiography, echocardiography, and two hours of Holter monitoring. This study found that obese dogs had increased plasma MDA and sympathovagal imbalance, which was indicated by impaired time and frequency domains compared to normal weight dogs. Although cardiac function was within normal limits, the echocardiographic study found that the obese dogs had reduced cardiac wall thickness and lower systolic function, as indicated by a reduction in %ejection fraction, %fractional shortening, increased left ventricular (LV) internal diameter during systole, and LV end-systolic volume compared to normal weight dogs. This study concluded that obesity in dogs can induce increased plasma oxidative stress, impaired HRV, and reduced cardiac systolic function compared to non-obese dogs.

Polyunsaturated Fatty Acid EAB-277® Supplementation Improved Heart Rate Variability and Clinical Signs in Tracheal Collapse Dogs

“…The present study also demonstrated that tracheal collapse is a chronic inflammatory disease, which induces the synthesis and secretion of pro-inflammatory cytokines such as TNF-α and IL-6, resulting in excessive reactive oxygen species (ROS). Interestingly, a previous study reported that both time and frequency domain HRV parameters such as SDNN, rMSSD, and LF/HF ratio correlated inversely with MDA level (32,33,48,49), which is consistent with the present study. Moreover, a previous study demonstrated that the rostral ventrolateral medulla (RVLM) of the brain stem region has an important role in controlling basal and reflex changes in sympathetic nervous system activity (50).…”

“…After that, a continuous 120 min (2 h) ECG segment was selected and analyzed using the MAR TM program. Power spectra of RR interval variability were obtained using the fast Fourier transform (FFT) algorithm and the three major oscillatory components, including high frequency (HF) (0.15–0.4 Hz), low frequency (LF) (0.04–0.15 Hz), and very low frequency (VLF) (0.003–0.04 Hz), were determined ( 33 ). The parasympathetic activity was regarded as HF, whereas sympathetic and parasympathetic activity associations were regarded as LF ( 34 , 35 ).…”

Acupuncture Improves Heart Rate Variability, Oxidative Stress Level, Exercise Tolerance, and Quality of Life in Tracheal Collapse Dogs

“…A previous study reported that HR after a 6-min walk test (6MWT) in dogs with myxomatous mitral valve disease was higher than that of the normal healthy dogs [68]. Pongkan et al, 2020 reported that the HR in obese dogs was higher than in normal BCS animals [61]. The dogs used in our study were obese and presumably had higher heart rates than normal weight dogs [61].…”

“…A previous study on obese male dogs demonstrated that a high level of plasma MDA impaired HRV, while a low level of plasma MDA improved HRV [57]. A decrease in MDA level may indirectly indicate a dominance of the parasympathetic nervous system [58].…”

Using bioelectrical impedance analysis for modeling regression and predicting body fat accumulation in dogs in East Thailand

“…A recent study determined that overweight and obesity can affect the serum concentration of symmetric dimethyl arginine [10]. Dog obesity causes several health problems and contributes to other disorders, such as musculoskeletal problems, respiratory distress, heart disease, and diabetes mellitus [11][12][13][14][15][16]. The most common cause of obesity is excessive energy intake over energy expenditure.…”