Veterinary clinical nutrition: success stories: an overview.

In this overview of success stories in veterinary clinical nutrition topics in cats and dogs reviewed include the dietary management of chronic kidney disease, dissolution of urinary tract uroliths by dietary modification, the recognition that taurine and L-carnitine deficiencies can cause dilated cardiomyopathy; that clinical signs associated with feline hyperthyroidism (caused by a benign adenoma) can be controlled by a low-iodine diet alone; that dietary management of canine osteoarthritis can also reduce non-steroidal anti-inflammatory drug doses; and that disease-free intervals and survival times can be statistically longer in dogs with Stage III lymphoma managed with diet. As we discover more about nutrigenetics and nutrigenomics, and as we expand our basic understanding of idiopathic diseases we are bound to identify more nutritionally related causes, and be able to develop novel dietary strategies to manage disease processes, including the formulation of diets designed to alter gene expression to obtain beneficial clinical outcomes.

Replacement of reduced highly unsaturated fatty acids (HUFA deficiency) in dilative heart failure: dosage of EPA/DHA and variability of adverse peroxides and aldehydes in dietary supplement fish oils.

OBJECTIVES: To explore the rationale for ω-3 fatty acids in heart failure treatment, the dosage of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) for replacing low levels of highly unsaturated fatty acids (HUFA deficiency) was examined. To judge the usefulness of various EPA/DHA preparations, their content of peroxides and aldehydes was determined. METHODS: In 298 patients with dilative heart failure, the serum HUFA level was assessed by gas chromatography. In ω-3-acid ethyl esters 90 (Omacor/Lovaza, approved by the Food and Drug Administration and the European Medicines Agency) and 63 dietary supplement fish oils, oxidation products were determined by photometry. RESULTS: Increasing serum HUFA from the lower (4.3 ± 1.0%) to the upper (9.5 ± 1.5%) tertile would be associated with an increased left ventricular (LV) ejection fraction (34.1 ± 9.9 vs. 28.3 ± 9.5%, p < 0.01) and reduced LV enddiastolic diameter (63.5 ± 7.1 vs. 66.9 ± 7.4 mm) requiring at least 2 g EPA/DHA daily. In fish oils, the peroxide and alkenal level varied greatly, i.e. peroxide value ≤ 5 mEq/kg in only 7 and ≤ 10 mEq/kg in 38 fish oils. Compared with equivalent doses of ω-3-acid ethyl esters 90, the mean peroxide intake would be 8.6 ± 6.1 and the alkenal intake 10.9 ± 4.4 times higher in fish oils. CONCLUSIONS: Levels of adverse oxidation products should be considered when targeting HUFA deficiency or treating patients with myocardial infarction or high triglycerides.

High intake of saturated fat, but not polyunsaturated fat, improves survival in heart failure despite persistent mitochondrial defects.

AIMS: The impact of a high-fat diet on the failing heart is unclear, and the differences between polyunsaturated fatty acids (PUFA) and saturated fat have not been assessed. Here, we compared a standard low-fat diet to high-fat diets enriched with either saturated fat (palmitate and stearate) or PUFA (linoleic and α-linolenic acids) in hamsters with genetic cardiomyopathy. METHODS AND RESULTS: Male δ-sarcoglycan null Bio TO2 hamsters were fed a standard low-fat diet (12% energy from fat), or high-fat diets (45% fat) comprised of either saturated fat or PUFA. The median survival was increased by the high saturated fat diet (P< 0.01; 278 days with standard diet and 361 days with high saturated fat)), but not with high PUFA (260 days) (n = 30-35/group). Body mass was modestly elevated (∼10%) in both high fat groups. Subgroups evaluated after 24 weeks had similar left ventricular chamber size, function, and mass. Mitochondrial oxidative enzyme activity and the yield of interfibrillar mitochondria (IFM) were decreased to a similar extent in all TO2 groups compared with normal F1B hamsters. Ca(2+)-induced mitochondrial permeability transition pore opening was enhanced in IFM in all TO2 groups compared with F1B hamsters, but to a significantly greater extent in those fed the high PUFA diet compared with the standard or high saturated fat diet. CONCLUSION: These results show that a high intake of saturated fat improves survival in heart failure compared with a high PUFA diet or low-fat diet, despite persistent mitochondrial defects.

Supplemental vitamin D and calcium in the management of African Americans with heart failure having hypovitaminosis D.

INTRODUCTION: A dyshomeostasis of macro- and micronutrients, including vitamin D and oxidative stress, are common pathophysiologic features in patients with congestive heart failure (CHF). In African Americans (AA) with CHF, reductions in plasma 25(OH)D are of moderate-to-marked severity (<20 ng/mL) and may be accompanied by ionized hypocalcemia with compensatory increases in serum parathyroid hormone (PTH). The management of hypovitaminosis D in AA with CHF has not been established. METHODS: Herein, a 14-week regimen: an initial 8 weeks of oral ergocalciferol (50,000 IU once weekly); followed by a 6-week maintenance phase of cholecalciferol (1400 IU daily); and a CaCO3 (1000 mg daily) supplement given throughout was designed and tested. Fourteen AA patients having a dilated (idiopathic) cardiomyopathy with reduced ejection fraction (EF, <35%) were enrolled: all completed the initial 8-week course; and 12 complied with the full 14 weeks. At baseline, 8 and/or 14 weeks, serum 25(OH)D and PTH; serum 8-isoprostane, a biomarker of lipid peroxidation, and echocardiographic EF were monitored. RESULTS: Reduced 25(OH)D at entry (14.4 ± 1.3 ng/mL) was improved (P < 0.05) in all patients at 8 weeks (30.7 ± 3.2 ng/mL) and sustained (P < 0.05) at 14 weeks (30.9 ± 2.8 ng/mL). Serum PTH, abnormally increased in 5 patients at baseline (104.8 ± 8.2 pg/mL), was reduced at 8 and 14 weeks (74.4 ± 18.3 and 73.8 ± 13.0 pg/mL, respectively). Plasma 8-isoprostane at entry (136.1 ± 8.8 pg/mL) was reduced at 14 weeks (117.8 ± 7.8 pg/mL; P < 0.05), whereas baseline EF (24.3 ± 1.7%) was improved (31.3 ± 4.3%; P < 0.05). CONCLUSIONS: Thus, the 14-week course of supplemental vitamin D and CaCO3 led to healthy 25(OH)D levels in AA with heart failure having vitamin D deficiency of moderate-to-marked severity. Albeit a small patient population, the findings suggest that this regimen may attenuate the accompanying secondary hyperparathyroidism and oxidative stress and improve ventricular function.

How to successfully achieve salt restriction in dialysis patients? What are the outcomes?

Despite the fact that dietary salt restriction is the most logical measure to prevent accumulation of salt and water in patients without renal function, it is not applied in most dialysis centers. In this review, the reasons for this unlucky development are analyzed. First, it appears that many dialysis patients are slightly overhydrated, but this is often not noticed and, if so, the deleterious effects in the long run are not appreciated. These consist not only of 'drug-resistant' hypertension, but also dilatation of the cardiac compartments leading to preventable cardiovascular events. Second, there are practical reasons why salt restriction is neglected. It is very difficult to buy salt-poor food. Salt consumption is an addiction, which can be overcome, but time and efforts are needed to achieve that. Suggestions are made how to reach that goal. Finally, examples are given how cardiac damage (often considered irreversible) can be improved or even cured by a 'volume control' strategy, whose crucial part is serious salt restriction.

Fish oil supplementation improves left ventricular function in children with idiopathic dilated cardiomyopathy.

Fish oil has a cardioprotective effect in adults with ischemic heart disease. The authors examined the effects of fish oil in children with idiopathic dilated cardiomyopathy (DCM). Eighteen DCM patients (group I) and 12 healthy children (group III) were given fish oil (10 mL/d). Their cardiac findings were compared with those of 11 patients with DCM who did not receive fish oil (group II). After 6.62+/-1.70 months, left ventricular ejection fraction had increased by 8.44%+/-3.80% (P<.05), in group I; 2.48%+/-3.85% (not statistically significant) in group II; and 0.84%+/-2.34% (not statistically significant) in group III. Left ventricular internal diastolic diameter (mm) was reduced by 4.36+/-4.86 (P=.001) in group I and 1.92+/-5.37 (P=.263) in group II, but increased by 0.22+/-2.54 (not statistically significant) in group III. The results suggest that fish oil leads to accelerated improvement of left ventricular function. The authors believe that if these results are confirmed in larger studies, fish oil should be added to the standard anticongestive therapy of children with DCM.

Nutrition and cardiomyopathy: lessons from spontaneous animal models.

Spontaneously occurring dilated cardiomyopathy in dogs and hypertrophic cardiomyopathy in cats are common diseases and are vastly underutilized as models of human cardiac disease. The goals of nutrition are no longer limited to a low-sodium diet, as research is now showing that nutrients can modulate disease and be an important adjunct to medical therapy. Deficiencies of certain nutrients can contribute to cardiomyopathies, as with taurine, but some nutrients-such as n-3 fatty acids, carnitine, and antioxidants-may have specific pharmacologic benefits. Dogs and cats with spontaneous cardiomyopathies are an exciting and promising model for studying nutritional modulation of cardiac disease.

Taurine and carnitine in canine cardiomyopathy.

Some newer more promising therapies for dogs with dilated cardiomyopathy (DCM) are taurine and carnitine. Deficiencies of these nutrients have been shown to cause DCM in dogs, and some breeds of dogs have shown dramatic improvement in myocardial function after supplementation with one or both nutrients. Although most dogs diagnosed with DCM do not have a documented taurine or carnitine deficiency, they may still be benefit from supplementation. These nutrients are safe to administer to dogs. For some owners, the high cost of carnitine is the only deterrent to giving their dogs supplements of both nutrients.

Carnitine deficiency in patients with coeliac disease and idiopathic dilated cardiomyopathy.

BACKGROUND AND AIMS: Idiopathic dilated cardiomyopathy (IDCM) and coeliac disease (CD) are two pathological conditions which may lead, by different mechanisms, to malabsorption of various micronutrients, including carnitine, active in cardiac metabolism. The aim of the present investigation was primarily to evaluate differences in serum concentrations of total carnitine between IDCM patients and patients with IDCM associated with CD and then also to evaluate, in the latter, the effect of a gluten-free diet on serum concentrations of total carnitine. METHOD AND RESULTS: Serum carnitine was determined by enzymatic spectrophotometric assay in three groups of individuals: group A, 10 patients (5 males, 5 females), mean age 46.5+/-10.8 years, presenting isolated IDCM; group B, 3 patients (2 males, 1 female), mean age 34+/-8 years, with IDCM+CD; and group C, 10 healthy subjects (5 males, 5 females), mean age 38.6+/-11.1 years. All patients with IDCM belonged to class NYHA I-II. Mean concentrations of total serum carnitine in the group of patients with isolated IDCM (group A) were found to be lower than in the controls (group C). The concentrations in patients with IDCM associated with CD (group B) were lower than in the control group and also lower than in the isolated IDCM (group A). After 2 years on a gluten-free diet, patients presenting IDCM associated with CD showed a progressive increase in mean serum carnitine levels compared to values observed prior to the diet. CONCLUSIONS: Patients presenting IDCM associated with CD show a greater decrease in serum total carnitine levels than patients presenting the isolated form of IDCM. A gluten-free diet, in these patients, leads to a progressive increase in serum levels of this substance.

Dilated cardiomyopathy due to type II X-linked 3-methylglutaconic aciduria: successful treatment with pantothenic acid.

A case of dilated cardiomyopathy in a young boy secondary to type II 3-methylglutaconic aciduria is described. A metabolic cause for his dilated cardiomyopathy was suspected because of the development on the electrocardiogram of an unusual "camel's hump" shape of the T waves, and of progressive thickening with increasing echogenicity of the left ventricular wall. He initially improved on digoxin treatment, but did not maintain the response with conventional dietary treatment for this condition. Supplementation with L-carnitine was associated with rapid deterioration in cardiac state, and may be contraindicated in this condition. At a point when the patient was moribund, large doses of pantothenic acid, a precursor of coenzyme A, produced a dramatic and sustained improvement in myocardial function and in growth, neutrophil cell count, hypocholesterolaemia, and hyperuricaemia, which suggests that limitation of availability of coenzyme A is a fundamental pathological process in this condition. The clinical improvement has been maintained for 13 months, and myocardial function is now nearly normal. Oral pantothenol, unlike pantothenic acid, is not efficacious.