title: Conjugated linoleic acid prevents growth attenuation induced by corticosteroid administration and increases bone mineral content in young rats.
abstract: Corticosteroids are a common therapy in many disease states, despite frequent and potentially serious side effects. Nutritional supplementation with conjugated linoleic acid (CLA) has been shown to increase fat-free mass, whereas supplementation with n-3 and n-6 fatty acids has been shown to increase bone mineral density (BMD). To determine whether CLA can attenuate the side effects of 8 weeks of corticosteroid administration, we randomized twenty-four 5-week-old male Sprague-Dawley rats into 1 of 4 groups: control; control + methylprednisolone (7 mg.kg-1.week-1); CLA diet (1% CLA w/w); or CLA plus methylprednisolone. Body composition, bone mineral content (BMC), and BMD were assessed with dual-energy X-ray absorptiometry at the onset and at the end of the 8-week intervention. The mechanical properties of bone were determined using 3-point femur bending at the end of the intervention. Methylprednisolone resulted in an attenuation of the increase in body mass and lean mass over the 8 weeks (p < 0.05). CLA prevented the methylprednisolone-induced attenuation of body mass and lean mass accumulation. CLA also resulted in a greater increase in BMC (p < 0.05) in the lumbar spine. The energy at failure of the isolated femurs was increased with CLA (p < 0.05). Dietary CLA prevents many of the growth- and bone-related side effects arising from 8 weeks of corticosteroid administration, results in greater increases in BMC and BMD, and can contribute to an improvement in some of the mechanical properties of bone.
authors.affiliation: Centre for Muscle Metabolism and Biophysics, Faculty of Applied Health Science, Brock University, St. Catharines, ON L2S3A1, Canada. Brian.Roy@brochu.ca
authors.forename: Brian D
authors.initials: BD
authors.lastname: Roy
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Bourgeois
authors.forename: Christine
authors.initials: C
authors.lastname: Rodriguez
authors.forename: Eric
authors.initials: E
authors.lastname: Payne
authors.forename: Kathleen
authors.initials: K
authors.lastname: Young
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Shaughnessy
authors.forename: Mark A
authors.initials: MA
authors.lastname: Tarnopolosky
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000818:Animals; D001823:Body Composition / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects*; D019587:Dietary Supplements; D005269:Femur / Q000187:drug effects; D005938:Glucocorticoids / Q000008:administration & dosage*; D006128:Growth / Q000187:drug effects*; D006131:Growth Inhibitors / Q000008:administration & dosage*; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D000305:Adrenal Cortex Hormones; D005938:Glucocorticoids; D006131:Growth Inhibitors; D044243:Linoleic Acids, Conjugated; D008775:Methylprednisolone