It may be time to add insulin resistance to the list of major causes of laminitis. Recent research indicates impaired glucose uptake and postoperative conditions may weaken the hoof lamellae, which make horses more susceptible to this costly problem.
While laminitis is associated with obesity, sepsis and postoperative conditions with elevated inflammation levels, the precise causes of laminitis are still a mystery.
Using an in vitro approach to studying laminitis with hoof wall explants, recent studies have shown that removing glucose from the culture medium leads to rapid separation of hoof lamella tissue under stress force conditions, says Mandi Vick. This may be similar to a mechanism that may occur in natural cases of laminitis where there is no insulin resistance due to a suppressed ability of insulin to induce glucose uptake into cells.
The graduate research assistant at the University of Kentucky’s Maxwell H. Gluck Equine Research Center in Lexington, Ky., says there’s growing evidence to indicate both a correlative and causative relationship between inflammation and insulin resistance, such as when obese horses have a localized form of Cushing’s syndrome.
“Circulating concentrations of inflammatory molecules, including acute phase proteins and inflammatory cytokines, are elevated in obese human patients with even higher elevations in obese patients with insulin resistance and type II diabetes,” she says. “Further evidence indicates an inflammatory role in insulin resistance is derived from studies demonstrating a reversal of insulin resistance by administration of anti-inflammatory salicylates, such as aspirin.”
Once considered only as a…