Intra-articular triamcinolone acetonide injection results in increases in systemic insulin and glucose concentrations in horses without insulin dysregulation.

Abstract

BACKGROUND: Corticosteroids are a commonly used, inexpensive intra-articular treatment for osteoarthritis which may increase the risk for laminitis in horses due, in part, to hyperinsulinaemia. Humans with metabolic syndrome experience increases in insulin and glucose concentrations post-injection, but responses in horses are unknown. OBJECTIVES: To determine the effect of a single intra-articular (IA) dose of triamcinolone acetate (TA) on blood insulin and glucose concentrations. STUDY DESIGN: Before-after study. METHODS: Ten horses with normal insulin regulation as assessed by an oral sugar test received 18&#x2009;mg of TA into one middle carpal joint. Insulin and glucose concentrations were evaluated at baseline and 4, 6, 8, 24, 48, and 72&#x2009;h following IA corticosteroid injection. Differences from baseline were evaluated using a repeated measures ANOVA with Dunnett's multiple comparison testing or a Friedman test with Dunn's correction (significant at p&#x2009;<&#x2009;0.05). RESULTS: Mean&#x2009;&#xb1;&#x2009;SD blood insulin concentration post IA TA injection was increased at 6&#x2009;h (15.8&#x2009;&#xb1;&#x2009;3.1 &#x3bc;IU/mL, p&#x2009;=&#x2009;0.01), 24&#x2009;h (23&#x2009;&#xb1;&#x2009;5.8 &#x3bc;IU/mL, p&#x2009;&#x2264;&#x2009;0.001), and 48&#x2009;h (29&#x2009;&#xb1;&#x2009;13 &#x3bc;IU/mL, p&#x2009;&#x2264;&#x2009;0.01) compared to baseline (10&#x2009;&#xb1;&#x2009;12.3 &#x3bc;IU/mL), with the peak at 48&#x2009;h. Median&#x2009;&#xb1;&#x2009;95% CI blood glucose concentration post IA TA injection was increased at 6&#x2009;h (112.7&#x2009;&#xb1;&#x2009;20.3&#x2009;mg/dL, p&#x2009;=&#x2009;0.006), 8&#x2009;h (112.9&#x2009;&#xb1;&#x2009;21.4&#x2009;mg/dL, p&#x2009;=&#x2009;0.004), 24&#x2009;h (122.6&#x2009;&#xb1;&#x2009;14.6, p&#x2009;&#x2264;&#x2009;0.0001), and 48&#x2009;h (123.5&#x2009;&#xb1;&#x2009;15.4&#x2009;mg/dL, p&#x2009;&#x2264;&#x2009;0.0001) compared to baseline (89.2&#x2009;&#xb1;&#x2009;6.6&#x2009;mg/dL), with the peak at 48&#x2009;h. MAIN LIMITATIONS: Only horses with normal insulin regulation were evaluated. CONCLUSIONS: Blood insulin and glucose concentrations modestly increased for 48&#x2009;h following IA TA.