Cabergoline treatment in cats with diabetes mellitus and hypersomatotropism.

Abstract

OBJECTIVES: The aim of this study was to evaluate the safety and efficacy of cabergoline to control hypersomatotropism (HST) and diabetes mellitus (DM) in cats. METHODS: This was a prospective cohort study. Twenty-three cats with HST and concurrent DM were enrolled. Cats received a dose of 10&#x2009;&#x3bc;g/kg cabergoline q48h PO for 6 months. Serum insulin-like growth factor 1 (IGF-1) and fructosamine concentrations, insulin dose and Insulin Resistance Index (IRI) were measured at the time of diagnosis of HST and at the start of cabergoline treatment (t0), and 3 months (t1) and 6 months (t2) during cabergoline treatment. RESULTS: A decrease and normalization of serum IGF-1 concentration was observed in 35% and 26% of cats, respectively. Median IGF-1 (t0: 1350&#x2009;ng/ml [range 832-1501]; t1: 1284&#x2009;ng/ml [range 365-1501]; t2: 1240&#x2009;ng/ml [range 263-1501];&#x2009;=&#x2009;0.016) decreased significantly. Twelve cats underwent diagnostic imaging of the pituitary area. The median pituitary height at t0 of cats that experienced an IGF-1 reduction (n&#x2009;=&#x2009;5/12) was significantly lower compared with those that did not experience an IGF-1 reduction (n&#x2009;=&#x2009;7/12) (3.2&#x2009;mm [range 3.1-3.7] vs 6&#x2009;mm [range 3.5-9.5];&#x2009;=&#x2009;0.011). Median fructosamine (t0: 628&#x2009;&#xb5;mol/l [range 400-963]; t1: 404&#x2009;&#xb5;mol/l [range 249-780]; t2: 400&#x2009;&#xb5;mol/l [range 260-815];<0.0001), insulin dose (t0: 1.3&#x2009;IU/kg [range 0.5-4.6]; t0: 0.5 IU/kg [range 0-2.3]; t2: 0.4&#x2009;IU/kg [range 0-2.1];<0.0001) and IRI (t0: 800&#x2009;&#xb5;molIU/kgl [range 257-2700]; t1: 300&#x2009;&#xb5;molIU/kgl [range 0-1498]; t2: 250&#x2009;&#xb5;molIU/kgl [range 0-1498];<0.0001) decreased significantly during cabergoline treatment. Eight cats achieved diabetic remission between months 1 and 6 of cabergoline treatment (median time to achieve remission: 3 months [range 1-6]). Three cats experienced asymptomatic hypoglycemia. CONCLUSIONS AND RELEVANCE: Cabergoline was effective in normalizing IGF-1 concentration in 26% of cats. Cabergoline improved diabetes control and was associated with remission of DM in 35% of cases. Cabergoline could be a treatment option for cats with HST and DM, especially in those cases with a relatively small pituitary tumor.