title: Effects of l-Carnitine Supplementation on Serum Inflammatory Factors and Matrix Metalloproteinase Enzymes in Females with Knee Osteoarthritis: A Randomized, Double-Blind, Placebo-Controlled Pilot Study.
abstract: Considering the importance of inflammation in the pathogenesis of osteoarthritis (OA) and induction of pain, this study was aimed to investigate the effect of L-carnitine supplementation on serum inflammatory mediators and OA-associated pain in females with knee OA.
  
  
  
  In this clinical trial, 72 females with mild to moderate knee osteoarthritis started the study, divided into 2 groups to receive 750 mg/day L-carnitine (n = 36) or placebo (n = 36) for 8 weeks. Serum levels of Interleukine-1β (IL-1β), high-sensitivity C-reactive protein (hs-CRP), matrix metalloproteinases (MMPs)-1 and -13, and visual analog scale (VAS) for pain were assessed before and after supplementation. Data were analyzed by t test, Wilcoxon signed rank test, Mann-Whitney U test, and analysis of covariance.
  
  
  
  Only 69 patients (33 in the L-carnitine group and 36 in the placebo group) completed the study. L-Carnitine supplementation decreased serum IL-1β and MMP-1 levels significantly (p = 0.001 and p = 0.021, respectively); however, serum hs-CRP and MMP-13 levels did not change significantly (p > 0.05). In the placebo group, serum IL-1β levels increased significantly (p = 0.011), whereas other studied biomarkers did not change significantly. The mean VAS score decreased significantly in the L-carnitine and placebo groups by 52.67% and 21.82%, respectively (p < 0.001). Significant differences were only observed between the 2 groups in serum IL-1β (p < 0.001) and MMP-1 (p = 0.006) levels and mean VAS score (p = 0.002) after adjusting for baseline values and covariates.
  
  
  
  Despite observed beneficial effects of short-term supplementation of L-carnitine in decreasing serum inflammatory mediators and improving pain in knee OA patients, further studies are needed to achieve concise conclusions.
authors.affiliation: a Students' Research Committee , Tabriz University of Medical Sciences , Tabriz , IRAN.
authors.forename: Aida
authors.initials: A
authors.lastname: Malek Mahdavi
authors.affiliation: b Nutrition Research Center , Tabriz University of Medical Sciences , Tabriz , IRAN.
authors.forename: Reza
authors.initials: R
authors.lastname: Mahdavi
authors.affiliation: c Connective Tissue Diseases Research Center , Tabriz University of Medical Sciences , Tabriz , IRAN.
authors.forename: Sousan
authors.initials: S
authors.lastname: Kolahi
mesh_terms: D000893:Anti-Inflammatory Agents; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D002331:Carnitine / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D053583:Interleukin-1beta / Q000097:blood; D020781:Matrix Metalloproteinase 1 / Q000097:blood; D053509:Matrix Metalloproteinase 13 / Q000097:blood; D020782:Matrix Metalloproteinases / Q000097:blood*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000097:blood / Q000188:drug therapy*; D010865:Pilot Projects; D010919:Placebos
chemical_list: D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D053583:Interleukin-1beta; D010919:Placebos; D002097:C-Reactive Protein; D053509:Matrix Metalloproteinase 13; D020782:Matrix Metalloproteinases; D020781:Matrix Metalloproteinase 1; D002331:Carnitine
keywords: L-carnitine; inflammation; matrix metalloproteinase; osteoarthritis