Childhood weight gain and thyroid autoimmunity at age 60-64 years: the 1946 british birth cohort study.Ong KK, Kuh D, Pierce M, Franklyn JA. J Clin Endocrinol Metab. 2013 Apr;98(4):1435-42. doi: 10.1210/jc.2012-3761
Complex bidirectional relationships have been described between body weight, thyroid function, and risk of thyroid disorders, including thyroid autoimmunity. We used a life-course approach to examine the potential association of childhood or adult body weight with the risk of thyroid autoimmunity and other thyroid disorders at age 60-64 years in a large population-based birth cohort study.
At age 60-64 years, 10.9% of women (139 of 1277) and 2.3% of men (27 of 1185) reported they were taking T4, and 11.5% of women (122 of 1057) and 3.3% of men (33 of 997) had positive anti-TPO antibodies (>100 IU/mL), consistent with thyroid autoimmunity. Among women, both T4 use and positive anti-TPO antibodies at age 60-64 years were positively associated with childhood body weight, childhood overweight, and adult body mass index. Childhood weight gain between 0 and 14 years of age was positively associated with later T4 use (odds ratio 1.21, 95% confidence interval 1.03-1.42) and positive anti-TPO antibodies (1.21, 1.00-1.47). Women who were overweight or obese at age 14 years (127 of 972) had a higher risk of later positive anti-TPO antibodies (2.05, 1.12-3.76). In men and women without any thyroid disorders, serum free T4 concentrations were inversely associated with concurrent body mass index (P = .002).
Conclusions: Childhood weight gain and childhood overweight correlated with an increased prevalence of later hypothyroidism and thyroid autoimmunity, particularly in women.
COMMENT-A surprising and impressive correlation between early childhood weight gain (and persistently greater weight) and both hypothyroidism and positive TPO antobody status in adults is documented. The implication is that obesity somehow fosters autoimmunity, and this may be because a chronic “inflammatory state” is present in fat .This topic is muc h discussed recently. For example, see Duntas LH, Biondi B.The Interconnections Between Obesity, Thyroid Function, and Autoimmunity: The Multifold Role of Leptin. Thyroid. 2013 Apr 4. [Epub ],  or Matarese G, Procaccini C, De Rosa V  At the crossroad of T cells, adipose tissue, and diabetes. Immunol Rev. 2012 Sep;249(1):116-34 who discuss connections between obesity, the inflammosome, leptin, thyroid function, and immunity.