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A Decrease in γ‐Tocopherol Associates with Impaired Muscular Performance After Anterior Cruciate Ligament Surgery
Author(s) -
Barker Tyler,
Henriksen Vanessa,
Rogers Victoria,
Trawick Roy
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.920.1
Subject(s) - isometric exercise , medicine , anterior cruciate ligament , placebo , surgery , endocrinology , anesthesia , pathology , alternative medicine
We tested the hypothesis that a decrease in γ‐tocopherol (γT) increases serum cytokine concentrations and impairs muscular performance after an anterior cruciate ligament (ACL) injury and surgery. Subjects were randomly assigned to one of three groups: (1) placebo (n=14), (2) multi‐vitamin/‐mineral (MV; n=14), or (3) vitamins E (α‐ [600 mg RRR ‐α‐tocopherol, αT)] and γ‐ [600 mg of RRR ‐γT]) and C (1000 mg ascorbic acid, AA) (EC; n=15). Supplements were taken daily starting ~2‐wk prior to and concluding 16‐wk after surgery. Fasting blood samples were obtained and single‐leg peak isometric force measurements were performed at baseline (Bsl, prior to supplementation), before surgery (~120‐min – blood draw only), and 8‐wk, 12‐wk, and 16‐wk after surgery. An exercise protocol consisting of repetitive knee and hip extension and flexion contractions to exhaustion was performed on the injured limb at 16‐wk. αT, γT, AA, and cytokines were measured in each blood sample, and peak isometric force was measured on injured and non‐injured legs separately at each testing session. Plasma αT and AA increased (∼42% and 28%, respectively) in the MV and EC groups, while γT decreased (∼47%) in the MV and increased (∼153%) in the EC group. Serum cytokines and peak isometric forces were not different between groups. Time to exhaustion during the exercise protocol decreased (∼30%) in the MV group and correlated with the change (Bsl to 16‐wk) in plasma γT in the MV and EC groups (n=29, r=0.42, p<0.05). We conclude that a decrease in circulating γT hinders muscular performance after ACL reconstruction.