title: The impact of dialysis modality on skin hyperpigmentation in haemodialysis patients.
abstract: BACKGROUND
  Skin hyperpigmentation in end-stage renal disease (ESRD) patients has been attributed to the accumulation of middle-molecular-weight (MMW) substances. Although an MMW mechanism suggests that hyperpigmentation may be improved by high-flux haemodialysis (HF-HD) and haemodiafiltration (HDF), this possibility has not been explored. In the present study, we investigated the impact of different dialysis modalities on skin colour in HD patients.
  
  
  METHODS
  Eighty-two ESRD patients on HD were divided into low-flux HD (LF-HD), HF-HD and HDF groups. The melanin index (MI) and erythema index (EI) of the abdomen and the flexor side of the forearm (non-sun-exposed areas) and the forehead (sun-exposed area) were determined by using a narrow-band reflectance spectrophotometer at baseline and after 12 months.
  
  
  RESULTS
  Even though absolute values of baseline and follow-up MI and EI of the three sites were comparable among the three groups, forehead MI and EI were significantly decreased after 12 months in the HDF group (P < 0.05). In addition, the change in forehead MI was significantly greater in the HDF than in the LF-HD group (-1.0 +/- 2.4% versus 0.3 +/- 1.6%, P < 0.05). Moreover, beta(2)-microglobulin reduction rates were negatively correlated with both changes in forehead MI (P < 0.01) and EI (P < 0.05).
  
  
  CONCLUSIONS
  Skin colour of sun-exposed areas was signi- ficantly decreased in ESRD patients receiving HDF therapy, suggesting that enhanced removal of MMW substances by convection may prevent or reduce hyperpigmentation in HD patients.
authors.affiliation: Department of Internal Medicine, Yonsei University, Seoul, Korea.
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Moon
authors.forename: Dong Ki
authors.initials: DK
authors.lastname: Kim
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Chang
authors.forename: Chan Ho
authors.initials: CH
authors.lastname: Kim
authors.forename: Hyun Wook
authors.initials: HW
authors.lastname: Kim
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Park
authors.forename: Seung Hyeok
authors.initials: SH
authors.lastname: Han
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Yoo
authors.forename: Dae Suk
authors.initials: DS
authors.lastname: Han
authors.forename: Shin-Wook
authors.initials: SW
authors.lastname: Kang