Abstract
Hyperinsulinemia associated with equine metabolic syndrome (EMS) and pituitary pars intermedia dysfunction (PPID) is a risk factor for laminitis. Research in other species has shown elevated body iron levels as both a predictor and consequence of insulin resistance. In humans this is known as dysmetabolic hyperferritinemia. We examined the relationship between insulin and the iron index most indicative of total body iron load [ferritin] in field cases of 33 horses with hyperinsulinemia. Serum ferritin exceeded published reference range for 100% of the horses. We also performed a secondary data analysis of published data and found significantly elevated ferritin (P = .05) in horses considered hyperinsulinemic by dynamic insulin testing compared to horses with a normal response. This preliminary retrospective data set should increase awareness of the potential for iron overload in hyperinsulinemic horses and stimulate further study into the relationship between insulin and iron dysregulation.

Key words: equine, ferritin, hyperinsulinemia,iron overload