Metabolic profiling of serum from dogs with pituitary-dependent hyperadrenocorticism.

Hyperadrenocorticism (HAC) is one of the most common endocrine diseases in dogs characterized by excessive cortisol production caused by an adrenocorticotropic hormone (ACTH)-secreting tumor, namely pituitary-dependent HAC (PDH) or cortisol-secreting adrenal tumor. Metabolomics presents the ability to identify small molecule metabolites. Thus, the use of metabolomics techniques in canine PDH can provide information about the pathophysiology and metabolic changes in this disease. This study aimed to identify and compare differences in serum metabolites between dogs with PDH and healthy dogs. The metabolomic profile of 20 dogs diagnosed with PDH was compared with 20 healthy dogs using liquid chromatography/mass spectrometry (LC/MS), and metabolite discrimination was performed using partial least squares-discriminant analysis (PLS-DA), the variable important in projection (VIP) and fold changes (FC) group-wise comparisons. The hypergeometric test identified the significantly altered pathways. A total of 21 metabolites were found to be significantly different between the two groups. The major alterations were found in arachidonic and decanoic acid, and phospholipids related to phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI). These metabolites are related to insulin resistance and other complications (i.e. hypertension). Our results indicate that PDH produces changes in serum metabolites of dogs, and the knowledge of these changes can aid to better understanding of pathophysiological processes involved and contribute to potentially detect new biomarkers for this disease.

A preliminary evaluation of the circulating leptin/adiponectin ratio in dogs with pituitary-dependent hyperadrenocorticism and concurrent diabetes mellitus.

Leptin and adiponectin are thought to modulate insulin sensitivity and pancreatic ß-cell function, but there is limited information regarding the adipokine status of hyperglycemic dogs with hyperadrenocorticism. This study aimed to determine whether alterations in the leptin/adiponectin ratio, insulin sensitivity, and/or pancreatic ß-cell function are associated with diabetes mellitus (DM) in dogs with pituitary-dependent hyperadrenocorticism (PDH). A total of 48 client-owned dogs were included in this prospective observational study: 20 dogs with PDH (10 normoglycemic and 10 with DM), 15 dogs with DM, and 13 healthy dogs. The serum concentrations of leptin, adiponectin, resistin, interleukin (IL)-1ß, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF)-α were measured, and homeostatic model assessment indices (HOMAs) were calculated and compared among the groups. Serum leptin was significantly higher in PDH dogs with and without DM than in healthy and DM dogs, and it was lower in DM dogs than in PDH dogs without DM. Serum adiponectin was significantly lower in PDH dogs with DM than in healthy and PDH dogs, and it was significantly lower in DM dogs than in healthy dogs. Serum IL-10 was significantly higher in PDH dogs with DM than in healthy and PDH dogs without DM. The leptin/adiponectin ratio was significantly higher in PDH dogs with DM than in normoglycemic PDH dogs. Serum IL-6 concentrations were significantly higher in DM dogs than in healthy dogs. Serum IL-1ß concentration was significantly higher in DM dogs than in healthy dogs and PDH dogs with DM and without DM. Serum TNF-α and IL-18 concentrations were not different among groups. The HOMAß-cell function was significantly lower in PDH dogs with DM than in normoglycemic PDH dogs, while HOMAinsulin sensitivity was significantly lower in PDH dogs with DM than in healthy dogs. These results suggest that adipokine dysregulation, a reduction in insulin sensitivity, and a further impairment in pancreatic ß-cell function might predispose PDH dogs to DM. Further longitudinal study will be necessary to confirm this result.

Influence of dental restoration under general anaesthesia on the low-dose dexamethasone suppression test in dogs.

It was the aim of the study to assess the impact of a minor surgical intervention under general anaesthesia on results of a low-dose dexamethasone suppression test (LDDST) in dogs. Five clinically healthy dogs underwent a LDDST (standard protocol) prior and 1, 4, 7, 14 and 28 days after a dental restoration under general anaesthesia. All LDDSTs revealed negative results. On all test days after intervention some dogs had basal cortisol concentrations below the reference range. Accordingly, plasma cortisol concentrations 4 and 8 h after dexamethasone injection were noticeably lower than before surgery and often even below the lower detection limit of 2.0 ng/ml. The study results may indicate a suppressive effect of a minor surgery under general anaesthesia on cortisol measurements during LDDSTs. It may be speculated that this could possibly lead to false negative test results in the postsurgical period, although transfer of these results to clinical cases is subject to limitations.

Hyperadrenocorticism of calorie restriction contributes to its anti-inflammatory action in mice.

Calorie restriction (CR), which lengthens lifespan in many species, is associated with moderate hyperadrenocorticism and attenuated inflammation. Given the anti-inflammatory action of glucocorticoids, we tested the hypothesis that the hyperadrenocorticism of CR contributes to its attenuated inflammatory response. We used a corticotropin-releasing-hormone knockout (CRHKO) mouse, which is glucocorticoid insufficient. There were four controls groups: CRHKO mice and wild-type (WT) littermates fed either ad libitum (AL) or CR (60% of AL food intake), and three experimental groups: (a) AL-fed CRHKO mice given corticosterone (CORT) in their drinking water titrated to match the integrated 24-hr plasma CORT levels of AL-fed WT mice, (b) CR-fed CRHKO mice given CORT to match the 24-hr CORT levels of AL-fed WT mice, and (c) CR-fed CHRKO mice given CORT to match the 24-hr CORT levels of CR-fed WT mice. Inflammation was measured volumetrically as footpad edema induced by carrageenan injection. As previously observed, CR attenuated footpad edema in WT mice. This attenuation was significantly blocked in CORT-deficient CR-fed CRHKO mice. Replacement of CORT in CR-fed CRHKO mice to the elevated levels observed in CR-fed WT mice, but not to the levels observed in AL-fed WT mice, restored the anti-inflammatory effect of CR. These results indicate that the hyperadrenocorticism of CR contributes to the anti-inflammatory action of CR, which may in turn contribute to its life-extending actions.

The interpretive contribution of the baseline serum cortisol concentration of the ACTH stimulation test in the diagnosis of pituitary dependent hyperadrenocorticism in dogs.

BACKGROUND: Current recommendation for performing the ACTH stimulation test (ACTHST) for diagnosis of hyperadrenocorticism (HAC) advocates the collection of baseline serum cortisol concentration (BC), but no references for interpretation of its results exist. OBJECTIVE: Evaluate the contribution of BC of the ACTHST to the diagnosis of HAC. ANIMALS: Fifty-four dogs were evaluated for suspected HAC at a referral hospital. METHODS: Records of dogs that had been evaluated by ACTHST for suspected HAC were reviewed. Receiver operator characteristics (ROC) analyses were used to assess the performance of BC, post-stimulation serum cortisol concentrations (PC), post-to-baseline cortisol concentration difference (DeltaC) and quotient (RatioC) for the diagnosis of HAC by comparing the area under the ROC curve (AUC) of PC to each of the other tests. RESULTS: The AUC of PC (95% confidence interval [CI]: 0.92; 95% CI, 0.81-0.98) was significantly higher than AUCs of BC (0.70; 95% CI, 0.56-0.82; P = .01) and RatioC (0.55; 95% CI, 0.41-0.69; P < .001), and was not significantly different from AUC of DeltaC (0.86; 95% CI, 0.74-0.94; P = .09). An optimal cutoff value of 683 nmol/L (24.8 µg/dL) for PC yielded a sensitivity of 86% and a specificity of 94%, respectively, and a cutoff value of 718 nmol/L (26.0 µg/dL) yielded a specificity of 100% with of 81% sensitivity for the diagnosis of pituitary-dependent HAC. CONCLUSION AND CLINICAL IMPORTANCE: The PC had good discriminatory ability for the diagnosis of HAC. It was comparable to DeltaC, whereas BC and RatioC were ineffective. Current recommendations to collect samples for BC appear redundant.

Development of a plasminogen activator inhibitor (PAI-1) assay and comparison of plasma PAI-1 activity in hyperlipidemic/dyslipidemic dogs with either hyperadrenocorticism or diabetes mellitus, and healthy dogs.

Thrombosis is a serious complication of many canine diseases and may be related to decreased fibrinolytic potential. Plasminogen activator inhibitor-1 (PAI-1) is the key regulator of fibrinolysis with increased levels demonstrated in states of pro-thrombosis and abnormal lipid metabolism. Our objective was to develop and validate a canine PAI-1 activity assay and test whether dogs with hyperadrenocorticism or diabetes mellitus that are hyperlipidemic/dyslipidemic have increased plasma PAI-1 activity. Functionally active PAI-1 in the plasma sample was incubated with recombinant tissue plasminogen activator (tPA), allowing the formation of a 1:1 stoichiometric inactive complex. Residual unbound tPA was then reacted with excess plasminogen in the presence of a colorimetric plasmin substrate. Plasmin production is quantified by computing the area under the curve of time (x) vs optical density (y) plot and converted to tPA IU/mL by comparison to a calibration curve of tPA standards. PAI-1 activity was determined by calculating the proportion of exogeneous tPA suppressed by PAI-1 in plasma. Assay verification included assessment of linearity, specificity, precision, sensitivity, and stability. PAI-1 activity was increased in hyperlipidemic compared to healthy dogs, but there was no significant difference between dogs with hyperadrenocorticism and diabetes mellitus. A near significant decrease in activity was detected in thawed plasma stored for 20h at 4°C. Our successfully validated assay offers a new tool for investigating fibrinolysis in dogs. Investigation of PAI-1 activity in dogs with other diseases associated with an increased risk of thrombosis would be valuable. Future studies of PAI-1 activity should consider its lability.

[Features of influence adenosine, AMP and hyperadrenalinemiya on the immune status, metabolic enzymes of purine nucleotides and the antioxidant defense system]. / Osobennosti vozdeistviia adenozina, AMP i giperadrenalinemii na immunnyi status, fermenty metabolizma purinovykh nukleotidov i sistemu antioksidantnoi zashchity.

Administration of a large dose of adrenaline (4 mg/kg 60 min before analysis) increased blood levels of total leukocytes, lymphocytes, decreased T-cell suppressors, leukocyte migration inhibition reaction (LMIR) and NBT test, but increased the level of conjugated dienes (CD). Administration of AMPand adenosine increased levels of total leukocytes, lymphocytes, T- lymphocytes, T-helpers, decreased the level of malondialdehyde (MDA), LMIR, and T-cell suppressors. Sympathetic hyperactivation induced by administration of a large dose of adrenaline (4 mg/kg 60 min before analysis) was accompanied by an increase in heart and liver activities of glutathione peroxidase (GPx), catalase, AMP deaminase (AMPD), and adenosine deaminase (AD). Administration of AMP or adenosine caused a decrease in activities of glutathione reductase (GR), GPx, catalase, a decrease in the MDA level and an increase in activities of AMPD and AD in the heart. In the liver AMP and adenosine also caused a decrease in activities of glutathione reductase (GR), GPx, a decrease in the MDA level and an increase in activities of AMPD and AD. The data obtained suggest that administration of adrenaline, AMP, and adenosine influences activity of enzymes involved in purine nucleotide metabolism. However, in contrast to adrenaline, administration of AMP or adenosine does not provoke stress reaction.

Pre-trilostane and three-hour post-trilostane cortisol to monitor trilostane therapy in dogs.

It is recommended that trilostane therapy of canine hyperadrenocorticism is monitored using an ACTH stimulation test, however this has never been validated. Three cortisol concentrations (pre-trilostane, 3-hour posttrilostane and 1-hour post-ACTH stimulation) were compared to a clinical score obtained from an owner questionnaire. There were 110 sets of 3 cortisol measurements and questionnaires obtained from 67 trilostane treated dogs. Questionnaire results were used to classify each dog as well or unwell. Well dogs were then categorised as having excellent, moderate or poor hyperadrenocorticism control, using thresholds produced by 14 independent veterinarians. Correlation co-efficients were used to compare the three cortisol concentrations to the owner score and the Kruskal Wallis and Mann-Whitney U tests were used to compare the three cortisol concentrations between categories of control. Cortisol cut-off values between significantly different categories were determined using ROC curves. Pre-trilostane and 3-hour post-trilostane cortisol were better correlated to the owner score and had cut-offs to differentiate between categories of control that had superior sensitivity and specificity results, than the post-ACTH cortisol. Iatrogenic hypoadrenocorticism was not detected in any unwell dog. This study shows that the pre-trilostane and 3-hour post-trilostane cortisol are potentially better monitoring methods than the ACTH stimulation test.

Diurnal Plasma Cortisol Measurements Utility in Differentiating Various Etiologies of Endogenous Cushing Syndrome.

Cortisol diurnal variation may be abnormal among patients with endogenous Cushing syndrome (CS). The study objective was to compare the plasma cortisol AM/PM ratios between different etiologies of CS. This is a retrospective cohort study, conducted at a clinical research center. Adult patients with CS that underwent adrenalectomy or trans-sphenoidal surgery (n=105) were divided to those with a pathologically confirmed diagnosis of Cushing disease (n=21) and those with primary adrenal CS, including unilateral adrenal adenoma (n=28), adrenocortical hyperplasia (n=45), and primary pigmented nodular adrenocortical disease (PPNAD, n=11). Diurnal plasma cortisol measurements were obtained at 11:30 PM and midnight and at 7:30 and 8:00 AM. The ratios between the mean morning levels and mean late-night levels were calculated. Mean plasma cortisol AM/PM ratio was lower among CD patients compared to those with primary adrenal CS (1.4±0.6 vs. 2.3±1.5, p<0.001, respectively). An AM/PM cortisol ratio≥2.0 among patients with unsuppressed ACTH (>15 pg/ml) excludes CD with a 85.0% specificity and a negative predictive value (NPV) of 90.9%. Among patients with primary adrenal CS, an AM/PM cortisol≥1.2 had specificity and NPV of 100% for ruling out a diagnosis of PPNAD. Plasma cortisol AM/PM ratios are lower among patients with CD compared with primary adrenal CS, and may aid in the differential diagnosis of endogenous hypercortisolemia.

Lack of association between clinical signs and laboratory parameters in dogs with hyperadrenocorticism before and during trilostane treatment.

INTRODUCTION: Trilostane therapy, the treatment of choice for pituitary- dependent hyperadrenocorticism (HAC) in dogs, is monitored by assessing resolution of clinical signs and measuring adrenocortical reserve capacity with an ACTH-stimulation test. The aim of this prospective study was to evaluate agreement between clinical signs reported by owners and cortisol or ACTH concentrations before and during trilostane therapy (starting dose 1-2 mg/kg once daily). A questionnaire on signs of HAC was used and a clinical score calculated as the sum of the 9 questions. Eighteen questionnaires at diagnosis and 97 during therapy were filled out by owners of 32 dogs. An ACTH-stimulation test was performed at each reevaluation. There were weak correlations between abdominal girth, appetite or weight gain and cortisol concentrations during therapy. However, the clinical score did not correlate with cortisol or cACTH values. In 50% of dogs, trilostane application had to be changed from once daily to twice daily during the study. Clinical signs reported by owners matched poorly with cortisol or cACTH concentrations at any time point. If low-dose trilostane is used, treatment frequency often has to be increased.

INTRODUCTION: Le traitement au trilostane, médicament de choix dans les cas d'hyperadrénocorticisme hypophyso-dépendant chez le chien, est évalué sur la base de la disparition des symptômes cliniques et des résultats des tests de stimulation à l'ACTH. Le but de la présente étude prospective était de comparer les symptômes cliniques (évalués par les propriétaires) avec les concentrations de cortisol et d'ACTH endogène avant et durant un traitement au trilostane (dose initiale 1­2 mg/kg, 1× par jour). On a utilisé un questionnaire composé de 9 questions relatives aux symptômes cliniques sur la base desquels on a calculé un score clinique total. Dix-huit questionnaires ont été remplis au moment du diagnostic et 97 durant le traitement par les propriétaires de 32 chiens. Un test de stimulation à l'ACTH a été réalisé lors de chaque contrôle. Il existait de faibles corrélations entre le périmètre abdominal, l'appétit et la prise de poids et les taux de cortisol durant le traitement. Le score clinique total n'était toutefois pas corrélé avec les concentrations de cortisol ou d'ACTH. Chez la moitié des chiens, la dose de trilostane a du être répartie en deux prises journalières. Les symptômes cliniques jugés par les propriétaires montraient une mauvaise corrélation avec les taux de cortisol et d'ACTH durant le traitement au trilostane. Si on dose ce médicament de façon faible, il y a souvent lieu d'augmenter la fréquence des prises.

Serum cholecystokinin concentrations in dogs with naturally acquired pituitary-dependent hyperadrenocorticism.

OBJECTIVE To determine serum cholecystokinin (CCK) concentrations in dogs with pituitary-dependent hyperadrenocorticism (PDH) and to evaluate associations among CCK concentration, PDH, and gallbladder mucocele (GBM). ANIMALS 14 client-owned dogs with PDH and 14 healthy dogs. PROCEDURES Dogs were separated into 4 groups: healthy dogs without gallbladder sludge (group A; n = 7), healthy dogs with gallbladder sludge (group B; 7), dogs with PDH and gallbladder sludge (group C; 8), and dogs with PDH and GBM (group D; 6). Serum CCK concentrations were then measured before and 1, 2, and 4 hours after consumption of a high-fat meal. Concentrations in dogs with PDH were also measured before and after trilostane treatment. Results were compared among groups and assessment points. RESULTS Preprandial serum CCK concentrations in group C were significantly lower than those in groups A, B, and D, but no significant differences in postprandial CCK concentrations were identified among the groups 1, 2, or 4 hours after the meal. With respect to trilostane treatment of dogs with PDH, no significant differences were identified between pre- and post-trilostane serum CCK concentrations in group C or D. Median CCK concentration after trilostane treatment was higher in group D than in group C, but this difference was not significant. CONCLUSIONS AND CLINICAL RELEVANCE The outcomes in this study did not support the hypothesis that a low circulating CCK concentration affects the development of GBM in dogs with PDH.

Long-term follow-up of renal function assessing serum cystatin C in dogs with diabetes mellitus or hyperadrenocorticism.

BACKGROUND: Serum cystatin C (sCysC) is used as biomarker for glomerular filtration rate (GFR). The effects of diabetes mellitus (DM) on renal function in dogs are unclear. Some renal variables have been evaluated in dogs with hyperadrenocorticism (HAC), but not sCysC. OBJECTIVES: The purpose of this study was the validation of a particle-enhanced nephelometric immunoassay (PENIA) for measuring canine sCysC, and to assess renal function in dogs with DM or HAC. METHODS: A PENIA was analytically validated for canine sCysC by determining imprecision and linearity. In a longitudinal 6-month study, renal function of 14 DM dogs was assessed, using serum creatinine, GFR, urinary protein-to-creatinine (UPC) ratio, urinary markers, systolic blood pressure (SBP), and sCysC, and compared to 17 healthy dogs at baseline. Furthermore, sCysC was measured at initial presentation and during a 12-month follow-up in 22 HAC dogs. RESULTS: The sCysC intra- and inter-assay variation coefficients were < 8% and highly linear (r = .997). About 33% and 67% of DM dogs had persistent proteinuria and systemic hypertension, respectively, but there were no significant differences in GFR, UPC, and urinary markers over time, and compared with healthy dogs at initial presentation. Serum CysC decreased significantly (P < .05) over time within the DM group. It did not change significantly over time within the HAC group. CONCLUSIONS: A PENIA measured sCysC linearly and precisely. There were no clinically relevant renal alterations over time in dogs with DM, although persistent proteinuria was observed. In dogs with HAC, sCysC measurement was not useful, although significant GFR changes occurred over time.

Nonylphenol-induced hyperadrenalism can be reversed/alleviated by inhibiting of 11-ß hydroxysteroid dehydrogenase type 1.

We previously observed that nonylphenol (NP) exposure during development resulted in increases in body weight and hyperadrenalism in adult male offspring. The mechanism of hyperadrenalism includes the primary activation of the adrenal gland and the conversion of inactive glucocorticoids to active glucocorticoids by 11ß-HSD1. The inhibition of 11ß-HSD1 is investigated as a new therapeutic approach. This study examined the effect of PF915275 (a selective 11ß-HSD1 inhibitor) on hyperadrenalism and adipogenesis in male rats exposed to NP during development. The results showed that treatment with the 11ß-HSD1 inhibitor PF915275 reversed/alleviated NP-induced hyperadrenalism via the following mechanisms: (1) decreasing serum corticosterone, 11ß-hydroxylase, and aldosterone synthase levels; (2) significantly increasing PPARα protein and mRNA expression. In adipose tissue, NP significantly increased PPARγ mRNA expression, whereas PF915275 significantly decreased the level of mRNA expression; and (3) the expression of key regulators/enzymes in the adipogenesis metabolic pathway was also modulated.

Inflammatory cytokine and chemokine profiles are associated with patient outcome and the hyperadrenergic state following acute brain injury.

BACKGROUND: Traumatic brain injury (TBI) elicits intense sympathetic nervous system (SNS) activation with profuse catecholamine secretion. The resultant hyperadrenergic state is linked to immunomodulation both within the brain and systemically. Dysregulated inflammation post-TBI exacerbates secondary brain injury and contributes to unfavorable patient outcomes including death. The aim of this study was to characterize the early dynamic profile of circulating inflammatory cytokines/chemokines in patients admitted for moderate-to-severe TBI, to examine interrelationships between these mediators and catecholamines, as well as clinical indices of injury severity and neurological outcome. METHODS: Blood was sampled from 166 isolated TBI patients (aged 45 ± 20.3 years; 74.7 % male) on admission, 6-, 12-, and 24-h post-injury and from healthy controls (N = 21). Plasma cytokine [interleukin (IL)-1ß, -2, -4, -5, -10, -12p70, -13, tumor necrosis factor (TNF)-α, interferon (IFN)-γ] and chemokine [IL-8, eotaxin, eotaxin-3, IFN-γ-induced protein (IP)-10, monocyte chemoattractant protein (MCP)-1, -4, macrophage-derived chemokine (MDC), macrophage inflammatory protein (MIP)-1ß, thymus activation regulated chemokine (TARC)] concentrations were analyzed using high-sensitivity electrochemiluminescence multiplex immunoassays. Plasma catecholamines [epinephrine (Epi), norepinephrine (NE)] were measured by immunoassay. Neurological outcome at 6 months was assessed using the extended Glasgow outcome scale (GOSE) dichotomized as good (>4) or poor (≤4) outcomes. RESULTS: Patients showed altered levels of IL-10 and all chemokines assayed relative to controls. Significant differences in a number of markers were evident between moderate and severe TBI cohorts. Elevated IL-8, IL-10, and TNF-α, as well as alterations in 8 of 9 chemokines, were associated with poor outcome at 6 months. Notably, a positive association was found between Epi and IL-1ß, IL-10, Eotaxin, IL-8, and MCP-1. NE was positively associated with IL-1ß, IL-10, TNF-α, eotaxin, IL-8, IP-10, and MCP-1. CONCLUSIONS: Our results provide further evidence that exaggerated SNS activation acutely after isolated TBI in humans may contribute to harmful peripheral inflammatory cytokine/chemokine dysregulation. These findings are consistent with a potentially beneficial role for therapies aimed at modulating the inflammatory response and hyperadrenergic state acutely post-injury.

Diabetes Mellitus-Associated Functional Hypercortisolism Impairs Sexual Function in Male Late-Onset Hypogonadism.

Functional hypercortisolism is generated by conditions able to chronically activate hypothalamic-pituitary-adrenal axis and has been proven to have a negative role in several complications. However, no study has evaluated the possible influence of diabetes mellitus-associated functional hypercortisolism on male hypogonadism and sexual function. We aimed to identify any association of hypothalamic-pituitary-adrenal axis dysregulation measures with testosterone and sexual function in men simultaneously affected by diabetes mellitus and late-onset hypogonadism. Fifteen diabetes mellitus and late-onset hypogonadism subjects suffering from functional hypercortisolism and fifteen diabetes mellitus and late-onset hypogonadism subjects who were free of functional hypercortisolism were retrospectively reviewed. Clinical, hormonal, and sexual parameters were considered. Hypercortisolemic subjects showed higher values of body mass index, waist, and glycated hemoglobin and lower ones of testosterone compared to normocortisolemic ones. All sexual parameters, except for orgasmic function, were significantly worse in hypercortisolemic than in normocortisolemic subjects. Hypercortisolemic patients showed higher values of cortisol after dexamethasone and urinary free cortisol as well as a lesser ACTH response after corticotropin releasing hormone test (ACTH area under curve) compared to normocortisolemic ones. No significant association was found at Poisson regression analysis between hormonal and sexual variables in normocortisolemic patients. In hypercortisolemic subjects, negative and significant associations of cortisol response after corticotropin releasing hormone (cortisol area under curve) with erectile function (ß: -0.0008; p: 0.015) and total international index of erectile function score (ß: -0.0006; p: 0.001) were evident. This study suggests for the first time the impairing influence of the dysregulated hypothalamic-pituitary-adrenal axis on sexual function in diabetes mellitus-associated late-onset hypogonadism.

Serum paraoxonase 1 and butyrylcholinesterase in dogs with hyperadrenocorticism.

The aim of this study was to evaluate serum activities of paraoxonase 1 (PON1) using three substrates; (1) 4-nitrophenylacetate (PON1n), (2) phenylacetate (PON1p), and (3) 5-thiobutyl butyrolactonase (PON1t), and butyrylcholinesterase (BChE) in dogs with hyperadrenocorticism (HAC). Serum activities of PON1 and BChE were higher in dogs with HAC than healthy dogs. There were strong positive correlations between PON1 activity measured with the three different substrates. This study demonstrated increased serum PON1 and BChE activities in dogs with HAC that could be attributed to the direct effect of glucocorticoids and lipid mobilisation.

Effect of trilostane on hormone and serum electrolyte concentrations in dogs with pituitary-dependent hyperadrenocorticism.

BACKGROUND: The effects of trilostane on key hormones and electrolytes over 24 hours in dogs with pituitary-dependent hyperadrenocorticism (PDH) are unknown. OBJECTIVES: To determine the plasma concentration of cortisol, endogenous adrenocorticotropic hormone (ACTH), aldosterone, sodium, potassium, and ionized calcium concentrations, and plasma renin activity over a 24-hour period after administration of trilostane to dogs with well-controlled PDH. ANIMALS: Nine dogs (mean age 9.3 ± 0.67 years, mean weight 31.9 ± 6.4 kg) with confirmed PDH. METHODS: Prospective study. Thirty days after the first administration of trilostane, blood samples were taken at -30, 0 (baseline), 15, 30, 60, and 90 minutes, and 2, 3, 4, 6, 8, 12, 16, 20, and 24 hours after administration of trilostane and plasma concentration of cortisol, endogenous ACTH, aldosterone, sodium, potassium, ionized calcium, and renin activity were determined. RESULTS: Cortisol concentrations decreased significantly (P < .001) 2-4 hours after trilostane administration. From baseline, there was a significant (P < .001) increase in endogenous ACTH concentrations between hours 3-12, a significant increase (P < .001) in aldosterone concentration between hours 16-20, and a significant (P < .001) increase in renin activity between hours 6-20. Potassium concentration decreased significantly (P < .05) between hours 0.5-2. CONCLUSION AND CLINICAL IMPORTANCE: Treatment with trilostane did not cause clinically relevant alterations in plasma aldosterone and potassium concentration. Results suggest that in dogs with PDH, the optimal time point for an ACTH-stimulation test to be performed is 2-4 hours after trilostane dosing. Future studies are necessary to establish interpretation criteria for a 2- to 4-hour postpill ACTH-stimulation test.

Serum adipokine concentrations in dogs with naturally occurring pituitary-dependent hyperadrenocorticism.

BACKGROUND: An excess of intra-abdominal fat is observed frequently in dogs with hyperadrenocorticism (HAC). Adipokine dysregulation is a possible cause of complications related to visceral obesity, but little information is available on adipokine in dogs with naturally occurring HAC. OBJECTIVES: To examine the differences in the circulating adipokines concentrations in overweight dogs with and without pituitary-dependent HAC (PDH). ANIMALS: Thirty healthy dogs and 15 client-owned dogs with PDH. METHODS: Case-controlled observational study, which enrolled 15 overweight dogs diagnosed with PDH and 30 otherwise healthy dogs of similar body condition score. Nine of 15 dogs with PDH were treated with low-dose trilostane twice daily and reassessed after treatment. RESULTS: The serum leptin (P < .0001) and insulin (P < .0001) concentrations were significantly higher in the PDH group (leptin, 22.8 ± 8.8 [mean ± SD]; insulin, 9.1 ± 6.1) than the healthy group (leptin, 4.9 ± 3.7; insulin, 1.9 ± 0.9). However, there were no significant differences in the adiponectin, resistin, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-10, and IL-18 levels between the 2 groups. In the PDH group, the serum cortisol concentrations had a linear association with the leptin concentrations, and there were significant decreases in the leptin (P = .0039) and insulin (P = .0039) levels after trilostane treatment. However, the leptin and insulin levels remained higher after trilostane treatment than in healthy control dogs with similar body condition score. CONCLUSIONS AND CLINICAL IMPORTANCE: Hypercortisolemia in dogs with PDH might upregulate the circulating leptin levels. However, a large population-based study will be necessary to determine whether the upregulation of leptin is involved directly with the complications caused by HAC.

Disorders of hemostasis in overt and subclinical hypercortisolism.

Glucocorticoids are a group of hormones of a particular impact on hemostasis. Epidemiological studies show an approximately severalfold greater incidence of thromboembolic events in hypercortisolemic patients compared to those without hormonal disorders. The prothrombotic action of this steroid class is caused by both the direct impact of hypercortisolism on the activation of coagulation and the inhibition of fibrinolysis, as well as, the pathology of hemostasis due to metabolic disorders, which occur in this endocrinopathy. The aim of this study was to discuss the hemostasis abnormalities that occur in patients with overt and subclinical hypercortisolism with a particular emphasis on plasmatic coagulation, endogenous anticoagulation system, homocysteine and proinflammatory cytokines.

Characterization of thrombelastography over time in dogs with hyperadrenocorticism.

Canine hyperadrenocorticism (HAC) is a common endocrinopathy often associated with hypercoagulability, thrombosis and thromboembolism and it can contribute to increased morbidity and mortality. The condition results in increased, unregulated secretion of glucocorticoids (GCs). While prospective identification of hypercoagulability is challenging, thrombelastography (TEG) is a diagnostic tool that enables the detection of hypercoagulability in a clinical setting. The objective of this prospective cohort study was to serially assess coagulation in dogs with HAC using TEG to test the hypothesis that dogs with HAC have increased TEG maximal amplitude (MA) and that the MA would normalize once clinical control was achieved. Twenty-three dogs with naturally occurring HAC were enrolled and hemostatic (including TEG, platelet function, thrombin-antithrombin complexes and coagulation panel) and hematological variables were measured at presentation. TEG was serially monitored until clinical resolution of HAC was attained. At presentation, most dogs with HAC had increased MA values, increased thrombin-antithrombin complexes and many were hyperfibrinogenemic. Platelet function analyzer-100 (PFA-100) closure times were significantly prolonged. TEG tracings did not normalize in either medically- or surgically-managed dogs, but fibrinogen concentrations decreased. It seems that dogs with HAC have a complex coagulopathy in which hypercoagulability and platelet hyporeactivity or dysfunction might occur simultaneously. As TEG tracings did not normalize in well-controlled dogs, it is unlikely that increased blood GCs are solely responsible for TEG alterations seen in dogs with HAC.