title: Clinical significance of different carnitine levels for improving the prognosis of patients undergoing hemodialysis.
abstract: OBJECTIVE
  To investigate plasma-free carnitine (Fc), acylcarnitine (Ac), and total carnitine (Tc) levels in patients undergoing hemodialysis (HD), and to explore their clinical significance.
  
  
  METHODS
  A total of 20 subjects were in the normal control group and 133 patients undergoing HD were divided into medicated (received carnitine treatment) and non-medicated groups. The medicated group was further divided into three subgroups according to Fc level: Fc = 80-199, 200-299, and ≥ 300 μmol/L. We used non-derivative tandem mass spectrometry to determine carnitine levels, and clinical symptoms such as weakness, hypotension, and muscle cramps were recorded during dialysis.
  
  
  RESULTS
  Fc and Tc levels were significantly lower in the non-medicated group than in the control group, whereas Fc, Ac, and Tc levels were higher in the medicated than non-medicated group (p< .05). The medicated group had fewer symptoms during dialysis than the non-medicated group such as weakness, hypotension, and muscle cramps (p< .05). An additional comparison showed that the incidence rates of hypotension and muscle cramps in the Fc < 80-199 μmol/L group were significantly lower than those in the Fc ≥ 300 μmol/L medicated and non-medicated groups.
  
  
  CONCLUSIONS
  Patients undergoing HD have low carnitine levels. l-Carnitine can effectively increase Fc concentration and improve clinical symptoms; however, only the proper Fc range can reduce complications caused by dialysis. Thus, this range needs to be determined.
authors.affiliation: a Department of Nephrology , China-Japan Friendship Hospital , Beijing , China.
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Zhang
authors.affiliation: a Department of Nephrology , China-Japan Friendship Hospital , Beijing , China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhuo
authors.affiliation: a Department of Nephrology , China-Japan Friendship Hospital , Beijing , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
authors.affiliation: b Department of Pharmacy , China-Japan Friendship Hospital , Beijing , China.
authors.forename: Gang
authors.initials: G
authors.lastname: Cui
authors.affiliation: a Department of Nephrology , China-Japan Friendship Hospital , Beijing , China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: b Department of Pharmacy , China-Japan Friendship Hospital , Beijing , China.
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Zhang
authors.affiliation: a Department of Nephrology , China-Japan Friendship Hospital , Beijing , China.
authors.forename: Wen-Ge
authors.initials: WG
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002331:Carnitine / Q000097:blood* / Q000627:therapeutic use*; D016022:Case-Control Studies; D002681:China; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D006435:Renal Dialysis / Q000009:adverse effects*; D053719:Tandem Mass Spectrometry; D055815:Young Adult
chemical_list: D002331:Carnitine
keywords: Carnitine; hypotension; maintenance hemodialysis; muscle cramps; weakness