title: Subclinical hyperthyroidism is not associated with progression of cardiac mass and development of left ventricular hypertrophy in middle-aged and older subjects: results from a 5-year follow-up.
abstract: BACKGROUND
  Decreased serum TSH levels are associated with increased cardiovascular mortality in elderly, and subclinical hyperthyroidism (SCH) was associated with left ventricular hypertrophy (LVH) as a predictor of cardiovascular mortality in some cross-sectional and case-control studies. The aim was to assess whether SCH independently impacts development of LVH over time.
  
  
  METHODS
  Of 3300 participants of the population-based Study of Health in Pomerania those with overt hyperthyroidism, hypothyroidism, possible thyroid disease or missing echocardiographic baseline data or follow-up were excluded, resulting in a study population of 1112 individuals (556 women) aged 45-81 years. Echocardiographic left ventricular mass divided by height(2·7) (LVMI(ht)), and LVH(ht) (LVMI(ht) > 44 g/m(2·7) in women and > 48 g/m(2·7) in men) was measured at baseline and after 5-year follow-up (median 5·00; range 4·92; 5·08). Comparison of subjects with (n = 107) and without (n = 1005) SCH were made by linear and logistic regression models adjusted for age, gender, smoking status, hypertension, and waist circumference.
  
  
  RESULTS
  At follow-up, LVMI(ht) did not differ between subjects with and without SCH (50·2 g/m(2·7), interquartile range (IQR) 41·2; 59·5 vs 47·8 g/m(2·7), IQR 39·3; 56·9; P = 0·29). LVH(ht) was present in 66 (61·7%) subjects with and 543 (54·0%) persons without SCH (P = 0·13). Analyses revealed no association between SCH and progression of LVMI(ht) (β = -0·18; 95%-confidence interval (CI) -2·34; -1·99; P = 0·873), and development of LVH(ht) (relative risk 0·86, 95%-CI 0·60; 1·26; P = 0·462), respectively.
  
  
  CONCLUSIONS
  In this population-based sample, SCH had no impact on progression of LVMI and development of LVH during 5-year follow-up in subjects aged 45 years or older.
authors.affiliation: Department of Internal Medicine B, Ernst Moritz Arndt University, Greifswald, Germany. mdoerr@uni-greifswald.de
authors.forename: Marcus
authors.initials: M
authors.lastname: Dörr
authors.forename: Till
authors.initials: T
authors.lastname: Ittermann
authors.forename: Nicole
authors.initials: N
authors.lastname: Aumann
authors.forename: Anne
authors.initials: A
authors.lastname: Obst
authors.forename: Thorsten
authors.initials: T
authors.lastname: Reffelmann
authors.forename: Matthias
authors.initials: M
authors.lastname: Nauck
authors.forename: Henri
authors.initials: H
authors.lastname: Wallaschofski
authors.forename: Stephan B
authors.initials: SB
authors.lastname: Felix
authors.forename: Henry
authors.initials: H
authors.lastname: Völzke
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004452:Echocardiography; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000453:epidemiology / Q000503:physiopathology*; D017379:Hypertrophy, Left Ventricular / Q000453:epidemiology / Q000209:etiology*; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D055815:Young Adult