Association of hypertriglyceridemia with insulin resistance in healthy Miniature Schnauzers.

OBJECTIVE: To determine whether hypertriglyceridemia in Miniature Schnauzers is associated with insulin resistance. DESIGN: Case-control study. ANIMALS: 28 Miniature Schnauzers with hypertriglyceridemia and 31 Miniature Schnauzers for which serum triglyceride concentrations were within the reference range (control dogs). PROCEDURES: All dogs had no history of chronic disease, were free of clinical signs for at least 3 months prior to blood collection, and were not receiving any medications known to affect lipid metabolism or serum insulin concentration. Food was withheld from each dog for ≥ 12 hours; a 5- to 10-mL blood sample was collected and allowed to clot to obtain serum. Serum insulin and glucose concentrations were measured, and the homeostasis model assessment (HOMA) score was calculated (ie, [basal serum insulin concentration {mU/L} × basal serum glucose concentration {mmol/L}]/22.5). RESULTS: Median serum insulin concentration was significantly higher in hypertriglyceridemic Miniature Schnauzers (21.3 mU/L) than it was in control dogs (12.5 mU/L). The percentage of dogs with high serum insulin concentrations was significantly greater in the hypertriglyceridemic group (28.6%) than it was in the control group (6.5%; odds ratio, 5.8; 95% confidence interval, 1.1 to 30.2). Median HOMA score for hypertriglyceridemic Miniature Schnauzers (4.9) was significantly higher than that for control dogs (2.8). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that hypertriglyceridemia in Miniature Schnauzers is often associated with insulin resistance. Further studies are needed to determine the prevalence and clinical importance of insulin resistance in hypertriglyceridemic Miniature Schnauzers.

Identification of variants of the SPINK1 gene and their association with pancreatitis in Miniature Schnauzers.

OBJECTIVE: To evaluate the serine protease inhibitor, Kazal type 1 (SPINK1) gene for variants and to determine their possible association with pancreatitis in Miniature Schnauzers. ANIMALS: 39 Miniature Schnauzers with pancreatitis, 25 healthy Miniature Schnauzers, and 23 healthy dogs of other breeds. PROCEDURES: The entire canine SPINK1 gene with its intron-exon boundaries was initially sequenced in 22 Miniature Schnauzers. Then, 2 regions of the gene were sequenced in 65 additional canine DNA samples at the locations of variants identified in the initial sequencing of the entire SPINK1 gene. RESULTS: Analysis of the SPINK1 gene in Miniature Schnauzers revealed 3 closely associated variants in healthy Miniature Schnauzers and Miniature Schnauzers with pancreatitis. These variants consisted of 2 missense mutations in the second exon (N20K and N25T) and a poly T insertion in the third intron that was near the boundary of exon 3 (IVS3+26-27ins(T)33-39,15_61dup11). Pancreatitis was significantly associated with homozygous alleles for these 3 variants in Miniature Schnauzers. In healthy dogs of other breeds, only the 2 exon variants were identified. CONCLUSIONS AND CLINICAL RELEVANCE: Variants of the SPINK1 gene may be associated with the development of pancreatitis in Miniature Schnauzers.

Serum liver enzyme activities in healthy Miniature Schnauzers with and without hypertriglyceridemia.

OBJECTIVE: To determine whether hypertriglyceridemia in healthy Miniature Schnauzers is associated with high serum liver enzyme activities. DESIGN: Cross-sectional study. ANIMALS: 65 Miniature Schnauzers with serum triglyceride concentrations within the reference range (group 1), 20 Miniature Schnauzers with slightly high serum triglyceride concentrations (group 2), and 20 Miniature Schnauzers with moderately to severely high serum triglyceride concentrations (group 3). PROCEDURES: Questionnaires regarding each dog's medical history were completed, and serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and G-glutamyltransferase (GGT) activities were measured. RESULTS: Median serum ALP activity was significantly higher in group 3 than in group 1 or 2 dogs, but was not significantly higher in group 2 than in group 1 dogs. Median serum ALT activity was significantly higher in group 3 than in group 1 dogs, but was not significantly different between any of the other groups. Compared with group 1 dogs, group 2 and 3 dogs were significantly more likely to have high serum ALP activity (odds ratio, 26.2 and 192.6, respectively). Group 3 dogs also were significantly more likely to have high serum ALT activity (odds ratio, 8.0), serum AST activity (odds ratio, 3.7), and serum GGT activity (odds ratio, 11.3), compared with group 1 dogs. Group 3 dogs were significantly more likely (odds ratio, 31.0) to have > or = 2 high serum liver enzyme activities than were group 1 dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that moderate to severe hypertriglyceridemia was associated with high serum liver enzyme activities in Miniature Schnauzers.

Investigation of hypertriglyceridemia in healthy Miniature Schnauzers.

BACKGROUND: Idiopathic hypertriglyceridemia has been reported in Miniature Schnauzers (MS). However, studies investigating the prevalence of this disorder in a large population of MS are lacking. HYPOTHESIS: Hypertriglyceridemia is prevalent in healthy MS. ANIMALS: This study used 192 healthy MS and 38 healthy dogs of other breeds (control dogs). METHODS: Serum triglyceride and cholesterol concentrations were measured and statistically compared in both the MS and control group. Dogs were categorized based on their age, and median serum triglyceride concentrations were compared among different age groups. RESULTS: A total of 63 (32.8%) of the 192 MS had serum triglyceride concentrations above the reference range. In contrast, of the 38 control dogs, only 2 (5.3%) had serum triglyceride concentrations above the reference range. The median serum triglyceride concentration in MS was 73.5 mg/dL, which was significantly higher as compared to that of the control group (median, 55 mg/dL; P = .0005). Serum cholesterol concentration was above the reference range in 9 (9.0%) of 100 MS and in 2 (5.3%) of the control dogs. Mean serum cholesterol concentrations were not significantly different between the 2 groups (P = .1374). Median serum triglyceride concentrations in MS increased significantly with age (P < .0001), and there was a significant positive correlation between serum triglyceride concentrations and age (Spearman r = 0.47; P < .0001). There was no difference in serum triglyceride concentrations between male and female MS (P = .48). CONCLUSION: Healthy MS have a high prevalence of hypertriglyceridemia as compared to healthy dogs of other breeds. Both the prevalence and severity of hypertriglyceridemia increase with age.