Fenofibrate lowers lipid parameters in obese dogs

Fenofibrate reduces glucose-induced barrier dysfunction in feline enteroids

Diabetes mellitus (DM) is a common chronic metabolic disease in humans and household cats that is characterized by persistent hyperglycemia. DM is associated with dysfunction of the intestinal barrier. This barrier is comprised of an epithelial monolayer that contains a network of tight junctions that adjoin cells and regulate paracellular movement of water and solutes. The mechanisms driving DM-associated barrier dysfunction are multifaceted, and the direct effects of hyperglycemia on the epithelium are poorly understood. Preliminary data suggest that fenofibrate, An FDA-approved peroxisome proliferator-activated receptor-alpha (PPARα) agonist drug attenuates intestinal barrier dysfunction in dogs with experimentally-induced DM. We investigated the effects of hyperglycemia-like conditions and fenofibrate treatment on epithelial barrier function using feline intestinal organoids. We hypothesized that glucose treatment directly increases barrier permeability and alters tight junction morphology, and that fenofibrate administration can ameliorate these deleterious effects. We show that hyperglycemia-like conditions directly increase intestinal epithelial permeability, which is mitigated by fenofibrate. Moreover, increased permeability is caused by disruption of tight junctions, as evident by increased junctional tortuosity. Finally, we found that increased junctional tortuosity and barrier permeability in hyperglycemic conditions were associated with increased protein kinase C-α (PKCα) activity, and that fenofibrate treatment restored PKCα activity to baseline levels. We conclude that hyperglycemia directly induces barrier dysfunction by disrupting tight junction structure, a process that is mitigated by fenofibrate. We further propose that counteracting modulation of PKCα activation by increased intracellular glucose levels and fenofibrate is a key candidate regulatory pathway of tight junction structure and epithelial permeability.

Efficacy of a micronized, nanocrystal fenofibrate formulation in treatment of hyperlipidemia in dogs

Background

Safe, effective, and readily available drug therapies are required for the management of hyperlipidemia and its associated complications in dogs.

Objectives

To investigate the efficacy of a micronized, nanocrystal formulation of fenofibrate (Tricor) in the treatment of hyperlipidemia in dogs.

Animals

Ten client‐owned dogs with primary (n = 7) and secondary (n = 3) hyperlipidemia. All dogs had hypertriglyceridemia at baseline; 3 dogs also had hypercholesterolemia.

Methods

Prospective dose‐escalation study. Dogs were treated with fenofibrate orally once daily in up to 3 cycles of 21 days each. Fenofibrate dose was increased at the end of each cycle if hypertriglyceridemia persisted and adverse effects were not documented. Complete blood count, biochemistry, and urine protein:creatinine ratio were collected serially. Baseline (T0) parameters were compared to time of maximal reduction in serum triglyceride concentrations (T1) and reported as median (range).

Results

Triglycerides normalized in all dogs (T0 = 662 mg/dL [189‐2391]; T1 = 113 mg/dL [81‐132]; P = .002). Fenofibrate dose at T1 = 6.4 mg/kg PO q24h (range, 2.2‐13.5). T1 was achieved at 3 (n = 4), 6 (n = 4), and 9 (n = 2) weeks. Serum cholesterol concentrations decreased in 9 of 10 dogs. Quiet demeanor and firm stools in 1 dog were the only reported adverse reactions. Fenofibrate administration resulted in a significant reduction in median alkaline phosphatase activity (P = .049).

Conclusions and Clinical Importance

Over 21 to 63 days, TriCor was effective in the management of primary and secondary hyperlipidemia in dogs.

Mefepronic acid is associated with a decrease in serum liver enzyme activities in dogs with suspected hepatopathy

Although suspected hepatopathy in dogs can be assessed by the blood levels of both liver enzyme activities and functional liver parameters, very often the precise diagnosis of primary or secondary hepatobiliary diseases can remain uncertain. Therefore, in a number of patients, the therapeutic intervention has the purpose of slowing the progression of fibrosis and provide for optimal hepatic support. Recently the PPARs (peroxisome proliferator‐activated receptors) have been identified as a family of hepatic nuclear hormonal receptors, involved in the regulation of lipid and glucose metabolism. The aim of this work is to assess the effect of mefepronic acid (PMPA), a PPAR agonist, on liver enzyme markers in blood samples of dogs with suspected hepatopathies. Twenty dogs, with suspected hepatopathies, were divided into two groups: ten of them received subcutaneously daily 10 mg/kg of PMPA for 7 days (treated, group T), while the remaining dogs were treated with a conventional supportive treatment for hepatopathies consisting of ursodeoxycholic acid (UDCA) 10 mg/kg PO SID for 45 days (control, group C). PMPA yielded a faster decrease in liver enzyme activities compared to UDCA, that in most cases was maintained after the suspension of the treatment. These data suggest that PMPA might be considered as supportive treatment for dogs with suspected hepatopathy.

Fenofibrate treatment for severe hypertriglyceridemia in dogs

Lipid disorders are relatively common in dogs. Hyperlipidemia can be primary or secondary to other diseases. In humans, fenofibrate is used to control hypertriglyceridemia. In dogs, there are no studies evaluating fenofibrate in hypertriglyceridemia. The aim of the study was to evaluate the safety and efficacy of fenofibrate to control severe hypertriglyceridemia in dogs. A total of 124 dogs (n = 124) with severe hypertriglyceridemia (>300 mg/dL, 3.39 mmol/L) were randomly distributed in the fenofibrate group (n = 64) and the diet group (n = 60). Dogs of the fenofibrate group were treated with fenofibrate (10 mg/Kg) once daily. Dogs of the diet group were treated with low-fat diet (10%). Serum triglycerides (TGs), total cholesterol (TC), liver enzymes, and creatine kinase concentrations were evaluated, before and after 1 mo of medical or dietary treatment. Triglyceride concentrations were reduced with fenofibrate (P < 0.001), and 85.93% of the dogs normalized their levels. Triglyceride concentrations also decreased with low-fat diet (P < 0.001), but only 26.6% of the dogs normalized their levels. Triglyceride concentrations were reduced with fenofibrate (P < 0.01) and with low-fat diet (P < 0.01). Of the cases with hypercholesterolemia, 53.7% and 50% of the dogs normalized their TC concentrations, with fenofibrate and diet, respectively. No significant adverse effects were observed (3% showed diarrhea). Fenofibrate was safe and effective in reducing and normalizing TG concentrations in dogs with severe hypertriglyceridemia, regardless of the cause of hyperlipidemia. The low-fat diet was effective in reducing, but not normalizing, TG concentrations. Fenofibrate and low-fat diet were effective in reducing TC concentrations. This is the first study evaluating fibrates in dogs with severe hypertriglyceridemia and comparing results with a low-fat diet.

Clinofibrate improved canine lipid metabolism in some but not all breeds

The objectives of this study were to assess if Clinofibrate (CF) treatment improved lipid metabolism in dogs, and to clarify whether its efficacy is influenced by canine characteristics. We collected medical records of 306 dogs and performed epidemiological analyses. Lipid values of all lipoproteins were significantly decreased by CF medication, especially VLDL triglyceride (TG) concentration (mean reduction rate=54.82%). However, 17.65% of dogs showed drug refractoriness in relation to TG level, and Toy Poodles had a lower CF response than other breeds (OR=5.36, 95% CI=2.07-13.90). Therefore, our study suggests that genetic factors may have an effect on CF response, so genetic studies on lipid metabolism-related genes might be conducted to identify variations in CF efficacy.

Therapy of Canine Hyperlipidemia with Bezafibrate

BACKGROUND

Bezafibrate (BZF) is effective in the treatment of hypertriglyceridemia in human patients, but there are no data on its use in dogs.

OBJECTIVE

To assess the safety of BZF in hyperlipidemic dogs and its efficacy in decreasing serum triglyceride (TG) and cholesterol (CHO) concentrations.

ANIMALS

Forty-six dogs, 26 females and 20 males, mean (±SD) age of 9 (±3) years, with TG ≥150 mg/dL (33 dogs also were hypercholesterolemic [>300 mg/dL]).

METHODS

Prospective, uncontrolled clinical trial. Dogs were treated with bezafibrate once daily, using 200 mg tablets at a dosage of 4-10 mg/kg (depending on body weight). Serum TG and CHO concentrations and alanine aminotransferase (ALT) and creatine kinase (CK) activity before and after 30 days of treatment were compared.

RESULTS

Sixteen dogs (34.8%) had primary hyperlipidemia, and 30 dogs (65.2%) had secondary hyperlipidemia (including spontaneous hyperadrenocorticism [41.3%, n = 19/46], chronic treatment with glucocorticoids [10.8%, n = 5/46], and hypothyroidism [15.2%, n = 7/46]). After 30 days, serum TG concentration normalized (<150 mg/dL) in 42 dogs (91.3%) and CHO concentration normalized (<270 mg/dL) in 22 of 33 dogs (66.7%). There was no difference in baseline TG concentration between the primary and secondary hyperlipidemia subgroups, but the decrease in TG concentration after treatment was greater in the primary hyperlipidemia subgroup. No adverse effects were observed, but ALT activity decreased significantly after 30 days of treatment.

CONCLUSIONS AND CLINICAL IMPORTANCE

Over 30 days, BZF was safe and effective in treatment of primary and secondary hyperlipidemia in dogs.

Lipoprotein cholesterol and triglyceride concentrations associated with dog body condition score; effect of recommended fasting duration on sample concentrations in Japanese private clinics

The objectives of this study were to survey clinics’ guidance about recommended fasting duration (FD) prior to lipoprotein analysis, and to characterize lipoprotein cholesterol and triglyceride concentrations in obese and overweight dogs categorized on the basis of the 5-point body condition score (BCS) scale. A dataset was created from lipoprotein analysis medical records of 1,538 dogs from 75 breeds in 354 clinics from 2012 to 2013. A phone survey was conducted to obtain the clinics’ FD. Two-level linear mixed-effects models were applied to the data. Over 50% of the clinics said they recommended fasting for 12 hr or more. Dogs in clinics with FD 12 hr or more had lower chylomicron triglyceride concentrations than those in clinics with FD less than 8 hr (P=0.05). Mean (± SEM) BCS at sampling was 3.7 ± 0.02. Obese and overweight dogs had higher very low density lipoprotein (VLDL) and high density lipoprotein (HDL) cholesterol and triglyceride concentrations than ideal dogs (P<0.05), but no such difference was found for low density lipoprotein cholesterol and triglyceride concentrations (P≥0.07). Across all BCS, as dog age rose from 0 to 8 years old, HDL cholesterol concentrations decreased by 13.5 mg/dl, whereas VLDL triglyceride concentrations increased by 81.7 mg/dl (P<0.05). In conclusion, FD of 8 hr or less may affect lipoprotein lipid concentrations. Obese and overweight dogs were characterized as having high VLDL and HDL cholesterol and triglyceride concentrations.

Plasma lipid profiling across species for the identification of optimal animal models of human dyslipidemia

In an attempt to understand the applicability of various animal models to dyslipidemia in humans and to identify improved preclinical models for target discovery and validation for dyslipidemia, we measured comprehensive plasma lipid profiles in 24 models. These included five mouse strains, six other nonprimate species, and four nonhuman primate (NHP) species, and both healthy animals and animals with metabolic disorders. Dyslipidemic humans were assessed by the same measures. Plasma lipoprotein profiles, eight major plasma lipid fractions, and FA compositions within these lipid fractions were compared both qualitatively and quantitatively across the species. Given the importance of statins in decreasing plasma low-density lipoprotein cholesterol for treatment of dyslipidemia in humans, the responses of these measures to simvastatin treatment were also assessed for each species and compared with dyslipidemic humans. NHPs, followed by dog, were the models that demonstrated closest overall match to dyslipidemic humans. For the subset of the dyslipidemic population with high plasma triglyceride levels, the data also pointed to hamster and db/db mouse as representative models for practical use in target validation. Most traditional models, including rabbit, Zucker diabetic fatty rat, and the majority of mouse models, did not demonstrate overall similarity to dyslipidemic humans in this study.

A novel PPARalpha agonist ameliorates insulin resistance in dogs fed a high-fat diet

Agonism of peroxisome proliferator-activated receptor (PPAR) alpha, a key regulator of lipid metabolism, leads to amelioration of lipid abnormalities in dyslipidemic patients. However, whether PPARalpha agonism is an effective form of therapy for obesity-related insulin resistance associated with lipid abnormalities is unclear. The present study investigated the effects of a potent and subtype-selective PPARalpha agonist, KRP-101, in a nonrodent insulin-resistant animal model under pair-fed conditions. Beagle dogs were fed a high-fat diet for 24 wk to induce insulin resistance. During the final 12 wk, 0.03 mg x kg(-1) x day(-1) KRP-101 (n = 5) or vehicle (n = 5) was administered orally once a day. KRP-101 administration resulted in a significantly lower weight of overall visceral fat, which is associated with increased adiponectin and decreased leptin in serum. KRP-101 administration improved hyperglycemia and hyperinsulinemia as well as dyslipidemia in dogs fed a high-fat diet. Oral glucose tolerance test showed that KRP-101 administration improved glucose intolerance. The KRP-101 group showed a markedly lower hepatic triglyceride concentration. Lipid oxidation was increased in the liver and skeletal muscles of the KRP-101 group. These findings in the dog model suggest that the use of potent and subtype-selective PPARalpha agonists as a potentially relevant therapeutic approach to treat human insulin resistance associated with visceral obesity.

Chronic Activation of Peroxisome Proliferator-Activated Receptor-α with Fenofibrate Prevents Alterations in Cardiac Metabolic Phenotype without Changing the Onset of Decompensation in Pacing-Induced Heart Failure

Severe heart failure (HF) is characterized by profound alterations in cardiac metabolic phenotype, with down-regulation of the free fatty acid (FFA) oxidative pathway and marked increase in glucose oxidation. We tested whether fenofibrate, a pharmacological agonist of peroxisome proliferator-activated receptor-alpha, the nuclear receptor that activates the expression of enzymes involved in FFA oxidation, can prevent metabolic alterations and modify the progression of HF. We administered 6.5 mg/kg/day p.o. fenofibrate to eight chronically instrumented dogs over the entire period of high-frequency left ventricular pacing (HF + Feno). Eight additional HF dogs were not treated, and eight normal dogs were used as a control. [3H]Oleate and [14C]Glucose were infused intravenously to measure the rate of substrate oxidation. At 21 days of pacing, left ventricular end-diastolic pressure was significantly lower in HF + Feno (14.1 +/- 1.6 mm Hg) compared with HF (18.7 +/- 1.3 mm Hg), but it increased up to 25 +/- 2 mm Hg, indicating end-stage failure, in both groups after 29 +/- 2 days of pacing. FFA oxidation was reduced by 40%, and glucose oxidation was increased by 150% in HF compared with control, changes that were prevented by fenofibrate. Consistently, the activity of myocardial medium chain acyl-CoA dehydrogenase, a marker enzyme of the FFA beta-oxidation pathway, was reduced in HF versus control (1.46 +/- 0.25 versus 2.42 +/- 0.24 micromol/min/gram wet weight (gww); p < 0.05) but not in HF + Feno (1.85 +/- 0.18 micromol/min/gww; N.S. versus control). Thus, preventing changes in myocardial substrate metabolism in the failing heart causes a modest improvement of cardiac function during the progression of the disease, with no effects on the onset of decompensation.