Influence of dietary restriction and low-intensity exercise on weight loss and insulin sensitivity in obese equids.

Abstract

BACKGROUND: The importance of including exercise with dietary modification for the management of obese equids is not clearly understood. OBJECTIVES: To evaluate the effect of a practical low-intensity exercise regimen, in addition to dietary restriction, on indices of insulin sensitivity (SI) and plasma adipokine concentrations in obese equids. ANIMALS: Twenty-four obese (body condition score [BCS]&#x2009;&#x2265;&#x2009;7/9) horses and ponies. METHODS: Over a 12-week period, animals received either dietary restriction only (DIET) or dietary restriction plus low-intensity exercise (DIET+EX). All animals were provided with a restricted ration of grass hay at 1.25% body weight (BW) on a dry matter basis, providing 82.5% estimated digestible energy requirements. The DIET+EX group undertook low-intensity exercise 5 days per week on an automated horse walker. Before and after weight loss, total body fat mass (TBFM) was determined, indices of SI were calculated using minimal model analysis of a frequently sampled IV glucose tolerance test, and adipokines plus inflammatory biomarkers were measured using validated assays. RESULTS: Decreases in BCS, BW, and TBFM were similar between groups (all P&#x2009;>&#x2009;.05). After weight loss, animals in both groups had decreased basal insulin and leptin concentrations, and increased adiponectin concentrations (all P&#x2009;<&#x2009;.001). Furthermore, animals in the DIET+EX group had significantly improved SI and decreased serum amyloid A concentrations relative to animals in the DIET group (both P&#x2009;=&#x2009;.01). CONCLUSIONS AND CLINICAL IMPORTANCE: Regular low-intensity exercise provided additional health benefits compared with dietary restriction alone in this population of obese equids.