Decrease of nitric oxide and increase in diastolic blood pressure are two events that affect renal function in dogs with pituitary dependent hyperadrenocorticism

Abstract

Hyperadrenocorticism is a frequent disease in dogs. The excess of circulating cortisol affects different organs and metabolic pathways, producing severe adverse effects that endanger the animal’s life. Among these effects, hypertension and renal damage can be mentioned. A group of 20 dogs with pituitary dependent hyperadrenocorticism (PDH) and 12 control dogs were used to study the following parameters: cortisol and nitric oxide (NO nit/nit) concentrations, diastolic and systolic blood pressure, renal artery resistance index by Doppler ultrasound, the rate of glomerular filtration by radio-renogram excretion and the presence of proteins in urine. Dogs with PDH showed a significantly lower NO nit/nit (P<0.0001) than the controls and this correlated with high values of diastolic and systolic pressure (r = -0.87; P<0.0001 and r = -0.81; P<0.0001 respectively). Most dogs (80%) are hypertensive mainly due to an increase in diastolic pressure, which correlated positively with the UPC (r = 0.8; P<0.001) and negatively with the glomerular rate of filtration (r = -0.58; P=0.007). Systolic pressure only increased in 60% of the cases and did not correlate with the mentioned variables. In PDH the decrease of NO affects blood pressure. The diastolic pressure would seem to have the greatest impact on the kidneys, therefore its evaluation and control are important to avoid and/or control renal damage.

Epidemiological, clinical, and laboratory aspects in a case series of canine hyperadrenocorticism: 115 cases (2010-2014)

“…This observation warrant monitoring of renal function and systemic hypertension control (Smets et al 2012b). Moreover, other studies have shown that proteinuria is directly correlated with blood pressure (Vidal et al 2018), and that HAC initial treatment with trilostane does not seem to be enough to normalize altered cardiovascular parameters in dogs (Soares et al 2016). In this scenario, it is important to note that the overexpression of the 11β-hydroxysteroid desidrogenase-1 enzyme in visceral adipose tissue of HAC patients could play a role in the maintenance of hypercortisolism in dogs with HAC (Miceli et al 2018).…”

Prevalence and risk factors associated with systemic hypertension in dogs with spontaneous hyperadrenocorticism

“…Descriptive statistics of the hematological, biochemical, and urinary variables studied Systemic hypertension is highly prevalent in both humans and dogs with hypercortisolism. [3][4][5][6][7][11][12][13][14][26][27][28][29] However, few studies have focused on the prevalence and risks factors for SH in dogs with naturally occurring HAC. In our study, the prevalence of SH was high (82%) and similar to data (70-85%) from people with CS.…”

“…2 Chronic hypercortisolism might lead to several complications such as diabetes mellitus (DM), systemic hypertension (SH), proteinuria, glomerulosclerosis, pancreatitis, gallbladder mucocele, increased susceptibility to infections, or pulmonary thromboembolism among others, both in humans and dogs. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Systemic hypertension associated with hypercortisolism is common in people, affecting 70%-85% of the patients. [4][5][6][7][8] The pathophysiological mechanisms for hypertension in HAC are incompletely understood, but in people a multifactorial model has been proposed with many pathways involved: the renin-angiotensin system, an increased mineralocorticoid activity, the sympathetic nervous system, the vasoregulatory system, metabolic factors, vascular remodeling and sleep apnea.…”

“…7,[23][24][25] Systemic hypertension is also recognized in dogs with HAC with a prevalence between 31% and 86%. [11][12][13][14][26][27][28][29] Some pathophysiological mechanisms have also been proposed, such as increased mineralocorticoid activity, 30,31 decreased nitric oxide concentrations 13 or increased renal vascular resistance. 26,32 There are few studies assessing the risk factors for SH in dogs with HAC; in previous studies, no difference in the prevalence or severity of SH is observed between dogs with PDH or ADH and there is no correlation between systolic blood pressure (SBP) and age, sex, reproductive status or results of the ACTH-stimulation tests.…”

“…A correlation between SBP and UPC but not with baseline cortisol concentrations has been described; however, other authors have found a correlation between SBP and baseline cortisol concentrations but not with UPC. [11][12][13][14] The objectives of our study were to determine the prevalence and severity of SH in dogs with naturally occurring HAC and to identify potential risks factors for SH in these dogs.…”