The Relationship Between Glycemic Response and the Incidence of OCD in Thoroughbred Weanlings: A Field Study

Abstract

Hyperglycemia and hyperinsulinemia have been implicated in the pathogenesis of osteochondrosis (Glade et al., 1984; Ralston, 1995). More specifically, foals that experience an exaggerated and sustained increase in circulating glucose or insulin in response to a carbohydrate (grain) meal may be predisposed to development of osteochondrosis. In vitro studies with fetal and foal chondrocytes suggest that the role of insulin in immature cartilage may be to promote chondrocyte survival or to suppress differentiation and that hyperinsulinemia may be a contributory factor to equine osteochondrosis (Henson et al., 1997). Rutgers University was recently granted a United States patent for diagnosing a predisposition for equine osteochondritis dissecans (OCD) using an oral glucose tolerance test (United States Patent). This patent was based on the premise that foals exhibiting an exaggerated glycemic response to an oral glucose challenge were more susceptible to developing OCD. The purpose of the present study was to evaluate if there is a relationship between a glycemic response test and the incidence of OCD in Thoroughbred weanlings, and to determine if this test would be useful in identifying factors that may predispose young growing horses to OCD.