Testosterone deprivation increases tendency to obesity but does not affect cardiac function in dogs

Abstract

Low testosterone levels in humans is associated with increased risk of cardiovascular diseases (CVD). A previous study reported that low testosterone can induce left ventricular dysfunction and cardiac mitochondrial impairment as well as increase the risk of ischemic heart disease. The effect of testosterone deprivation on cardiac function in dogs, however, has never been investigated. The present study tested the hypothesis that testosterone deprivation induces impairment of cardiac function in healthy castrated male dogs. In this study, twenty-three healthy male dogs were divided into two groups: an intact group (n = 15) and a castrated group which had been castrated at least 12 months (n = 8). Metabolic parameters, blood pressure, and cardiac function using electrocardiography and echocardiography were investigated. We found that although the testosterone level in the castrated group (0.48 ng/mL) was significantly lower than the intact group (5.88 ng/mL) (P < 0.05), metabolic parameters, blood pressure, and cardiac function were not different in the two groups. Castrated dogs did, however, have a higher body condition score than intact dogs. These findings suggest that testosterone deprivation in male dogs can induce obesity but that it does not induce impairment of cardiac function.