Ertugliflozin decreases the insulin spike in non-insulin dysregulated standardbred horses following intra-articular triamcinolone administration

Horses with equine metabolic syndrome (EMS) are at an increased risk of laminitis following corticosteroid use. Ertugliflozin reduces hyperinsulinemia in horses with EMS, and therefore may be a management option to reduce the insulin spike seen post corticosteroid use. It was hypothesised that oral ertugliflozin, administered before and after intra-articular (IA) triamcinolone acetonide (TA), will significantly lower the insulin response in comparison to placebo. A randomised, blinded, placebo-controlled, crossover design was performed on eight adult standardbred geldings with no history of laminitis. Once a day, horses were orally-administered with either 0.05 mg/kg of ertugliflozin or volume-matched placebo for four days before and four days after IA TA (18 mg) was administered into a middle carpal joint. Horses then had a two-week washout period before the same process was repeated with the alternative treatment (ertugliflozin or placebo) and opposite carpal joint injected. During the eight-day treatment periods, blood was collected each day at 8 am and 12 pm for analysis of blood insulin, glucose and triglycerides concentrations. Using Bayesian modelling, the maximum plasma insulin concentration (Cmax) for the post-TA period was 40.2 μIU/mL (95% credible interval: 13.2, 65.7) with placebo and 16.7 μIU/mL (95% CI: 1.76, 40.1) with ertugliflozin. There was a 99.13% probability that the ertugliflozin Cmax was lower than that for placebo. In conclusion, four once-daily doses of oral ertugliflozin (0.05 mg/kg) given prior to and again following IA TA administration, attenuated the rise in plasma insulin concentrations in non-insulin-dysregulated horses.