Hypothyroidism in the elderly.

Abstract

IN THE PAST, decreased thyroid function was believed to accompany the aging process. This was based primarily upon anatomical observations and by studies which evaluated thyroid function by means of function tests. In this review we will present an overview of the information concerning thyroid function in the elderly. Divergent results on thyroid gland volume have been reported. Some studies indicate that, with advancing age, the human thyroid decreases in volume (1). In contrast, others have reported that the thyroid gland increases in weight with age, reaching an average of 35–40 g in subjects aged 70 yr (2). There is a marked increase in microscopic and clinically palpable nodules with age (1). The prevalence of thyroid nodularity has been reported to vary between 25% (3) to as high as 90% in women over the age of 70 yr and 60% in men over the age of 80 yr (4). With advancing age there is progressive fibrosis with scattered lymphocytes and rare plasma cells in the stroma (1, 3). These anatomical changes per se may not be particularly relevant since elderly subjects generally have adequate thyroid hormone production. In fact, in one study it was observed that the weight and histology of the gland did not correlate with thyroid function as evaluated by the free (F) T4 index (I) (3).