Spontaneous hypothyroidism in adult women is predicted by small body size at birth and during childhood.
BACKGROUND
The relationships of early growth with coronary heart disease and type 2 diabetes have received considerable attention. It is not known whether fetal or childhood growth is linked with autoimmune disorders.


OBJECTIVE
Our objective was to assess whether the risk of adult-onset spontaneous hypothyroidism is predicted by body size at birth and during childhood.


METHODS
We conducted a birth cohort study in Helsinki, Finland.


METHODS
A total of 293 women who were born between 1934 and 1944 and had their heights and weights recorded at birth and during childhood participated in the study.


METHODS
We measured spontaneous hypothyroidism, defined as: 1) a disease history confirmed from medical records, or 2) previously undiagnosed hypothyroidism (TSH > 10 mU/liter).


RESULTS
Twenty women (6.8%) had spontaneous hypothyroidism; 18 had been diagnosed previously, between 43 and 65 yr of age, and two had undiagnosed subclinical hypothyroidism. In addition, 59 women were thyroid peroxidase antibody positive. Compared with the 214 thyroid peroxidase antibody-negative women with no thyroid disorder, those with spontaneous hypothyroidism had on average 252 g [95% confidence interval (CI), 61 to 443 g; P = 0.01] lower birth weight and 1.2 cm (95% CI, 0.5 to 2.0 cm; P = 0.002) shorter length at birth. The odds of developing hypothyroidism increased 4.4-fold per kilogram decrease in birth weight (95% CI, 1.4 to 14.1). Hypothyroid subjects had been shorter in early childhood and had lower body mass index during later childhood.


CONCLUSIONS
Small body size at birth and during childhood increases the risk of spontaneous hypothyroidism in adult women.
Kajantie
Eero
E
National Public Health Institute, Department of Epidemiology and Health Promotion, Mannerheimintie 166, 00300 Helsinki, Finland. eero.kajantie@helsinki.fi
Phillips
David I W
DI
Osmond
Clive
C
Barker
David J P
DJ
Forsén
Tom
T
Eriksson
Johan G
JG
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D001724:Birth Weight / Q000502:physiology*; D001827:Body Height / Q000502:physiology; D049628:Body Size / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis* / Q000453:epidemiology*; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008875:Middle Aged; D011379:Prognosis; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; D013972:Thyrotropin; C056658:TPO protein, human; D007453:Iodide Peroxidase; D013974:Thyroxine