title: A meta-analysis of the associations between common variation in the PDE8B gene and thyroid hormone parameters, including assessment of longitudinal stability of associations over time and effect of thyroid hormone replacement.
abstract: OBJECTIVE
  Common variants in PDE8B are associated with TSH but apparently without any effect on thyroid hormone levels that is difficult to explain. Furthermore, the stability of the association has not been examined in longitudinal studies or in patients on levothyroxine (l-T(4)).
  
  
  METHODS
  Totally, four cohorts were used (n=2557): the Busselton Health Study (thyroid function measured on two occasions), DEPTH, EFSOCH (selective cohorts), and WATTS (individuals on l-T(4)).
  
  
  METHODS
  Meta-analysis to clarify associations between the rs4704397 single nucleotide polymorphism in PDE8B on TSH, tri-iodothyronine (T(3)), and T(4) levels.
  
  
  RESULTS
  Meta-analysis confirmed that genetic variation in PDE8B was associated with TSH (P=1.64 × 10(-10) 0.20 s.d./allele, 95% confidence interval (CI) 0.142, 0.267) and identified a possible new association with free T(4) (P=0.023, -0.07 s.d./allele, 95% CI -0.137, -0.01), no association was seen with free T(3) (P=0.218). The association between PDE8B and TSH was similar in 1981 (0.14 s.d./allele, 95% CI 0.04, 0.238) and 1994 (0.20 s.d./allele, 95% CI 0.102, 0.300) and even more consistent between PDE8B and free T(4) in 1981 (-0.068 s.d./allele, 95% CI -0.167, 0.031) and 1994 (-0.07 s.d./allele, 95% CI -0.170, 0.030). No associations were seen between PDE8B and thyroid hormone parameters in individuals on l-T(4).
  
  
  CONCLUSIONS
  Common genetic variation in PDE8B is associated with reciprocal changes in TSH and free T(4) levels that are consistent over time and lost in individuals on l-T(4). These findings identify a possible genetic marker reflecting variation in thyroid hormone output that will be of value in epidemiological studies and provides additional evidence that PDE8B is involved in TSH signaling in the thyroid.
authors.affiliation: Henry Wellcome Laboratories for Integrative Neurosciences and Endocrinology, University of Bristol, Bristol BS1 3NY, UK.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Taylor
authors.forename: Vijay
authors.initials: V
authors.lastname: Panicker
authors.forename: Adrian
authors.initials: A
authors.lastname: Sayers
authors.forename: Beverley
authors.initials: B
authors.lastname: Shields
authors.forename: Ahmed
authors.initials: A
authors.lastname: Iqbal
authors.forename: Alexandra P
authors.initials: AP
authors.lastname: Bremner
authors.forename: John P
authors.initials: JP
authors.lastname: Beilby
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Leedman
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Hattersley
authors.forename: Bijay
authors.initials: B
authors.lastname: Vaidya
authors.forename: Timothy
authors.initials: T
authors.lastname: Frayling
authors.forename: Jonathan
authors.initials: J
authors.lastname: Evans
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Tobias
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Timpson
authors.forename: John P
authors.initials: JP
authors.lastname: Walsh
authors.forename: Colin M
authors.initials: CM
authors.lastname: Dayan
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000235:genetics*; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D056726:Genetic Association Studies / Q000379:methods*; D014644:Genetic Variation / Q000235:genetics*; D020249:Hormone Replacement Therapy / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D013963:Thyroid Hormones / Q000097:blood / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D013963:Thyroid Hormones; D015105:3',5'-Cyclic-AMP Phosphodiesterases; C468781:PDE8B protein, human