title: Carpal tunnel surgery as proxy for dialysis-related amyloidosis: results from the Japanese society for dialysis therapy.
abstract: OBJECTIVE
  This study aims to identify current risk factors for developing dialysis-related amyloidosis using carpal tunnel syndrome (CTS) as proxy for general amyloidosis.
  
  
  METHODS
  The cohort consisted of 166,237 patients on dialysis (mean age 66.1 ± 12.4 years; mean dialysis vintage 7.2 ± 6.4 years) who could be followed for a year between 2010 and 2011. Of these, 2,157 (1.30%) needed first-time CTS surgery during the study period. Odds ratios (ORs) for CTS were calculated at a 95% confidence interval (95% CI) after adjusting for age, gender, primary kidney disease, history of smoking, history of hypertension vintage, dialysis modality, use of high-flux membrane, body mass index, serum albumin, Kt/V, normalized protein catabolic rate, C-reactive protein, pretreatment β2-microglobulin (β2MG), and β2MG clearance.
  
  
  RESULTS
  Adjusted ORs of first-time CTS for vintages 10-15, 15-20, 20-25 (referent), 25-30, and >30 years were, respectively, 0.18 (0.12-0.26), 0.43 (0.31-0.62), 1.00, 2.37 (1.64-3.40), and 3.87 (2.52-5.93). Adjusted ORs for ages 40-50, 50-60 (referent), 60-70, 70-80, and >80 were 0.53 (0.30-0.94), 1.00, 1.89 (1.41-2.52), 1.52 (1.08-2.14), and 1.04 (0.60-1.80). Female gender, low serum albumin, and diabetic nephropathy were also associated with CTS. Pretreatment serum β2MG and β2MG clearance <80% were not significant, although β2MG clearance >80% was negatively associated with CTS [OR 0.34 (0.13-0.90)].
  
  
  CONCLUSIONS
  ORs of first-time CTS almost doubled with every 5-year increase in dialysis vintage. ORs of CTS were highest for patients aged 60-70. Other factors associated with CTS were gender, serum albumin, and diabetic nephropathy. β2MG clearance >80% may decrease the incidence of CTS.
authors.affiliation: Nephrology Center, Toranomon Hospital, Tokyo, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Hoshino
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yamagata
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nishi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nakai
authors.forename: Ikuto
authors.initials: I
authors.lastname: Masakane
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Iseki
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Tsubakihara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000453:epidemiology* / Q000209:etiology; D002349:Carpal Tunnel Syndrome / Q000453:epidemiology* / Q000601:surgery*; D003928:Diabetic Nephropathies / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects / Q000706:statistics & numerical data*; D012307:Risk Factors; D012709:Serum Albumin / Q000378:metabolism; D012737:Sex Factors; D013997:Time Factors; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D012709:Serum Albumin; D001613:beta 2-Microglobulin