Thyroid autoantibodies epidemiological studies

The other problem is the differences in the epidemiological methods applied. It is well-established that thyroid autoantibodies are more commonly measurable in females than in males (Hollowell et al., 1998 Laurberg et ai, 1998 Prentice et al., 1990 Tunbridge et ai, 1977), and that the prevalence of antibodies increases with age, at least in females (Pedersen et al, 2003). It is possible that this increase is present only up to a certain age, after which there may be a plateau (Aghini-Lombardi et al, 1999 Hawkins et al, 1980 Tunbridge et al, 1977). The results obtained from the population studies should therefore be age and sex standardized before comparison. Some studies included highly selective participants, such as subjects above 70 years... 

Comparison of epidemiological studies on the prevalence of circulating thyroid autoantibodies in areas with different iodine intakes is therefore difficult, unless the studies are designed as comparatives with exactly the same methods applied in two or more regions. 

A number of studies on the epidemiology of thyroid autoantibodies have been performed as descriptive studies in iodine-deficient areas. Results from some population-based studies from both iodine-deficient and iodine-sufficient areas are shown in Table 60.1. The results are ambiguous. 

Thyroid autoantibodies were present in only a few cases, and a search for goitrogens was negative. Further epidemiologic studies showed that endemic areas were located mainly on schistoIithic non-caIcareous soil, with superficial drinking water, deficient in iodine and several other minerals, frequently polluted (Malamos et al. 1971). 

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