title: Effects of a docosahexaenoic acid-rich microalgae nutritional product on insulin sensitivity after prolonged dexamethasone treatment in healthy mature horses.
abstract: OBJECTIVE
  To determine effects of a microalgae nutritional product on insulin sensitivity in horses.
  
  
  METHODS
  8 healthy mature horses. PROCEDURES :Horses (n = 4/group) received a basal diet without (control diet) or with docosahexaenoic acid-rich microalgae meal (150 g/d) for 49 days (day 0 = first day of diet). On day 28, an isoglycemic hyperinsulinemic clamp procedure was performed. Horses then received dexamethasone (0.04 mg/kg/d) for 21 days. On day 49, the clamp procedure was repeated. After a 60-day washout, horses received the alternate diet, and procedures were repeated. Plasma fatty acid, glucose, and insulin concentrations and glucose and insulin dynamics during the clamp procedure were measured on days 28 and 49. Two estimates of insulin sensitivity (reciprocal of the square root of the insulin concentration and the modified insulin-to-glucose ratio for ponies) were calculated.
  
  
  RESULTS
  Baseline glucose and insulin concentrations or measures of insulin sensitivity on day 28 did not differ between horses when fed the control diet or the basal diet plus microalgae meal. On day 49 (ie, after dexamethasone administration), the microalgae meal was associated with lower baseline insulin and glucose concentrations and an improved modified insulin-to-glucose ratio for ponies, compared with results for the control diet.
  
  
  CONCLUSIONS
  Although the microalgae meal had no effect on clamp variables following dexamethasone treatment, it was associated with improved plasma glucose and insulin concentrations and insulin sensitivity estimates. A role for microalgae in the nutritional management of insulin-resistant horses warrants investigation.
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Brennan
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Graugnard
authors.forename: Malinda L
authors.initials: ML
authors.lastname: Spry
authors.forename: Tammy
authors.initials: T
authors.lastname: Brewster-Barnes
authors.forename: Allison C
authors.initials: AC
authors.lastname: Smith
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Schaeffer
authors.forename: Kristine L
authors.initials: KL
authors.lastname: Urschel
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology; D004032:Diet / Q000662:veterinary*; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology; D015309:Glucose Clamp Technique / Q000662:veterinary; D005951:Glucose Tolerance Test / Q000662:veterinary; D006734:Horse Diseases / Q000178:diet therapy / Q000517:prevention & control*; D006736:Horses; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D005938:Glucocorticoids; D007328:Insulin; D003907:Dexamethasone