Impact of month of birth on the development of autoimmune thyroid disease in the United Kingdom and Europe.
BACKGROUND
Viral/bacterial infection is proposed as a trigger for the autoimmune thyroid diseases (AITD): Graves' disease (GD) and Hashimoto's thyroiditis (HT). Previous studies in European Caucasian AITD subjects found higher birth rates in the autumn/winter, suggesting those born in the autumn/winter experience increased viral/bacterial exposure after birth, impacting upon immune system development and predisposing to AITD later in life.


OBJECTIVE
Month of birth effects were investigated in three independent European Caucasian AITD datasets.


METHODS
Variation in GD and HT onset was compared across months and seasons, with fluctuations across all 12 months analyzed using a Walter-Elwood test.


METHODS
The study was conducted at a research laboratory.


METHODS
National UK Caucasian AITD Case Control Collection (2746 GD and 502 HT compared with 1 423 716 UK births), National UK Caucasian GD Family Collection (239 GD and 227 unaffected siblings), and OXAGEN AITD Caucasian Family Collection (885 GD, 717 HT, and 794 unaffected siblings of European Caucasian decent).


METHODS
Case-control and family-based association studies were measured.


RESULTS
No consistent month of birth effects were detected in GD females or males across all three collections. In HT females from the OXAGEN AITD Caucasian Family Collection, slightly higher birth rates were detected in autumn (Walter's test statistic = 7.47, P = .024) however, this was not seen in the HT females from the case-control cohort.


CONCLUSIONS
Our results suggest in UK/Northern European Caucasian GD subjects, month of birth does not impact on AITD development. Although some month of birth effects for HT females in one collection cannot be excluded, only further work in larger European Caucasian AITD collections can confirm these effects.
Oxford Centre for Diabetes, Endocrinology, and Metabolism (A.H., J.A.H.W., S.C.L.G., M.J.S.), Department of Physiology, Anatomy, and Genetics (G.D., S.V.R.), and Oxford National Institute for Health Research Biomedical Research Centre (J.C.T.), Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7LE, United Kingdom; Centre for Endocrinology, Diabetes, and Metabolism (P.R.N., J.D.C.-S., J.A.F.), School of Clinical and Experimental Medicine, College of Medical and Dental Science, Institute of Biomedical Research, University of Birmingham, Birmingham B15 2TT, United Kingdom; Northern General Hospital (A.A.), Sheffield S5 7AU, United Kingdom; Royal Bournemouth Hospital (M.A.), Bournemouth BH7 7DW, United Kingdom; Department of Endocrinology and Metabolism (T.H.B., L.H.), Odense University Hospital, DK-5000 Odense, Denmark; Department of Medicine (K.C.), University of Cambridge, Cambridge CB2 1TN, United Kingdom; School of Medicine (J.M.C.), University of Dundee, Dundee DD1 9SY, United Kingdom; Department of Medicine (P.J.H.), University of Otago, Dunedein 9016, New Zealand; Centre for Endocrine and Diabetes Sciences (J.H.L.), Cardiff University, Cardiff C14 4XN, United Kingdom; Institute of Genetic Medicine (S.H.P.), Newcastle University, Newcastle-upon-Tyne NE1 3BZ, Newcastle, United Kingdom; Kolling Institute (B.G.R.), Royal North Shore Hospital and The University of Sydney, Sydney NSW 2006, Australia; Royal Devon and Exeter Hospital (B.V.), Exeter EX2 5DW, United Kingdom; Department of Endocrinology and Metabolism (W.M.W.), University of Amsterdam, 1100 DE Amsterdam, The Netherlands; Department of Human Metabolism (A.P.W.), University of Sheffield, Sheffield S10 2RX, United Kingdom; and Oxford National Institute for Health Research Biomedical Research Centre (S.C.L.G.), Churchill Hospital, Oxford OX3 7LE, United Kingdom.
Alexander
A
Hamilton
Paul R
PR
Newby
Jacqueline D
JD
Carr-Smith
Giulio
G
Disanto
Amit
A
Allahabadia
Mary
M
Armitage
Thomas H
TH
Brix
Krishna
K
Chatterjee
John M
JM
Connell
Laszlo
L
Hegedüs
Penny J
PJ
Hunt
John H
JH
Lazarus
Simon H
SH
Pearce
Bruce G
BG
Robinson
Jenny C
JC
Taylor
Bijay
B
Vaidya
John A H
JA
Wass
Wilmar M
WM
Wiersinga
Anthony P
AP
Weetman
Sreeram V
SV
Ramagopalan
Jayne A
JA
Franklyn
Stephen C L
SC
Gough
Matthew J
MJ
Simmonds
D016022:Case-Control Studies; D004198:Disease Susceptibility / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D036801:Parturition / Q000276:immunology*; D012307:Risk Factors; D012621:Seasons; D035781:Siblings; D013967:Thyroiditis, Autoimmune / Q000453:epidemiology*; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D044465:White People