Serum spexin concentration, body condition score and markers of obesity in dogs.

Background: Spexin (SPX) is a peptide hormone that regulates body weight, adipose tissue metabolism, and food intake.

Hypothesis: Serum SPX concentration correlates with body condition score (BCS) and markers of obesity in dogs.

Animals: Fifty-seven dogs of varying body condition assessed using a 5-point BCS.

Methods: Prospective, nonblinded, observational cohort study. Serum SPX concentration was measured using commercially available radioimmunoassay (RIA) in dogs with varying BCS. Spexin mRNA and protein expression were detected using real-time quantitative polymerase chain reaction and immunofluorescence staining.

Results: Serum SPX concentration was lower in dogs with BCS4 (8.56 +/- 2.86) and BCS5 (6.7 +/- 2.12) compared to BCS2 (11.96 +/- 2.23) and BCS3 (10.51 +/- 2.19; BCS2 vs BCS5, P < .001 and BCS2 vs BCS4, P = .005; BCS3 vs BCS5, P = .002). Spexin mRNA was detected in adipose tissue, liver and pancreas. Spexin protein was expressed in adipose tissue and liver but not in pancreas. There were negative correlations between SPX and serum concentration of insulin (P < .05); leptin (P < .01), triglycerides (P < .01), total cholesterol (P < .01), nonesterified fatty acids (P < .01), and fructosamine (P < .01). There was a positive correlation between SPX and serum concentration of adiponectin (P < .01).

Conclusions And Clinical Importance: Spexin could be involved in pathogenesis of obesity in dogs, and might be considered as a potential marker for obesity.