Thyroid Autoimmunity and Ageing

Abstract

Ageing is associated with the appearance of several serum autoantibodies, including thyroid autoantibodies. The biological and clinical significance of this phenomenon is still unknown, since, with the exception of primary myxedema, the prevalence of clinically overt thyroid autoimmune diseases is not increased in the elderly. The peculiar link between autoimmune thyroid failure and ageing is also underscored by the high prevalence of subclinical hypothyroidism in elderly subjects with positive serum thyroid autoantibodies, and could be the consequence of preferential age-dependent expression of destructive effector mechanisms and/or increased target gland susceptibility. Thyroid autoimmunity and subclinical hypothyroidism have also been implicated in the pathogenesis of other age-associated disorders, in particular coronary heart disease. Interestingly, recent data from our laboratories showed that thyroid autoantibodies are rare in healthy centenarians and in other highly selected aged populations, while they are frequently observed in unselected or hospitalized elderly. Taken together, these data suggest that thyroid autoimmune phenomena are not the consequence of the ageing process itself, but rather might be related to age-associated disease.

Cognitive and neuropsychiatric aspects of subclinical hypothyroidism: Significance in the elderly

“…The estimates of TPO antibodies are much higher in older adults with SCH, ranging from 40% to 67% [13,18,21- 23], suggesting that the increased prevalence of thyroid antibodies in the elderly may reflect age-associated disease rather than normal age-related changes to the HPT axis. This is further supported by the findings by Pinchera et al [24], who found a similar incidence of circulating thyroid antibodies among healthy centenarians and younger healthy elderly individuals (aged 65 to 80) compared with young and middle-aged adults.…”

Age-dependent different action of curcumin in thyroid of rat.

“…On the one hand, some research findings reveal a slight, stimulating influence of curcumin that does not lead to hyperthyroidism in 3-month-old male rats [19]. The stimulating activity of curcumin may counteract the hypothyroidism connected with ageing of the thyroid gland, whereas its antiinflammatory activity shown in a number of in vitro and in vivo studies is assumed to prevent autoaggressive diseases which more often affect the thyroid gland in elderly than in young [20][21][22][23]. On the other hand, some experiments conducted on mice have demonstrated hyperplasia of the thyroid gland after prolonged curcumin administration [14].…”

Lower early morning plasma cortisol levels are associated with thyroid autoimmunity in the elderly

“…It is thus possible that the age-associated decline in ThAbs is specifically found in studies including only disease-free females aged above 65 years. In studies performed in unselected populations (including hospitalized patients), the rise in thyroid antibody frequency with age may persist in the older age groups (2).…”

“…Immunosenescence is a well-characterized phenomenon accompanying ageing and represents a malfunction of the immune system leading to both increased infection susceptibility and increased frequency of certain kinds of autoimmune disorders in older age (1,2). Several mechanisms have been postulated (3,4) including neuroendocrine changes (5).…”