title: Clinical implications of subclinical hypothyroidism in continuous ambulatory peritoneal dialysis patients.
abstract: BACKGROUND
  Despite the high prevalence of subclinical hypothyroidism in patients with chronic kidney disease, little is known about the clinical features and implications of this disorder in end-stage renal disease patients. This study aimed to investigate the clinical implications of subclinical hypothyroidism in continuous ambulatory peritoneal dialysis (CAPD) patients.
  
  
  METHODS
  This is a cross-sectional study with 51 stable patients who were maintained on CAPD for more than 3 months. A thyroid function test with blood sampling and echocardiography were conducted. Subclinical hypothyroidism was defined as a thyrotropin (TSH) level over 5 mIU/l and normal free T(4).
  
  
  RESULTS
  Of the 51 patients, subclinical hypothyroidism was detected in 14 (27.5%). Among those with subclinical hypothyroidism, only 4 (28.6%) patients had autoimmune thyroiditis. Patients with subclinical hypothyroidism had lower left ventricular ejection fractions (LVEF; 61.5 vs. 70.0%, p = 0.002) and lower fractional shortening at endocardial levels (endoFS; 33.9 vs. 40.0%, p = 0.009) compared to those with normal TSH levels. In addition, logTSH was inversely associated with LVEF (r = -0.361, p = 0.009) and endoFS (r = -0.320, p = 0.022). In a multivariate linear regression, adjusted for age, diabetes, previous coronary artery disease and logCRP (C-reactive protein), logTSH was an independent correlate with LVEF (beta = -0.388, p < 0.001).
  
  
  CONCLUSIONS
  This study suggests that subclinical hypothyroidism is common and might be implicated in cardiac dysfunction in CAPD patients.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, NHIC Ilsan Hospital, Koyang, Kyungki-do, Seoul, Korea.
authors.forename: Ea Wha
authors.initials: EW
authors.lastname: Kang
authors.forename: Ju Young
authors.initials: JY
authors.lastname: Nam
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Yoo
authors.forename: Suk Kyun
authors.initials: SK
authors.lastname: Shin
authors.forename: Shin-Wook
authors.initials: SW
authors.lastname: Kang
authors.forename: Dae-Suk
authors.initials: DS
authors.lastname: Han
authors.forename: Seung Hyeok
authors.initials: SH
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000379:methods*; D012044:Regression Analysis; D013599:Systole; D013972:Thyrotropin / Q000378:metabolism
chemical_list: D013972:Thyrotropin