Hyperthyroidism in elderly hospitalised patients. Clinical features and treatment outcomes

Abstract

Objective: To review the clinical features and response to treatment of hyperthyroidism in elderly hospitalised patients.

Participants and setting: Sixty patients over the age of 70: 41 admitted to a geriatric hospital and 19 to an acute-care hospital, 1990-1993.

Methods: Thyroid function tests were performed routinely in the geriatric hospital but only on demand at the acute-care hospital. Hyperthyroidism was defined as elevation of plasma free thyroxine (FT4) or total tri-iodothyronine (T3) level and suppression of thyroid-stimulating hormone (TSH) level. Seventy-seven per cent of patients were seen personally; in the remainder details were obtained from their hospital records. Outcome was assessed by clinical and biochemical improvement.

Results: Clinical features - Fifty-two women and eight men with hyperthyroidism were identified. Their average age was 80.2 years (range, 70-101; median, 80.0). The most common clinical features were weight loss (83%) and atrial fibrillation (60%); 58% were agitated and 15% apathetic. Fifty-two per cent had cognitive impairment with either dementia or confusion. The diagnosis was not initially suspected in 62%. Thyroid antibodies were absent in 35/40 and an isotope scan showed a nodular thyroid in 27/29. Contrast radiography with iodine-containing media had been performed within the preceding six months in 23% of patients. Treatment and outcome - Forty-seven patients were treated with antithyroid drugs in standard doses and 21 received radioactive iodine. In 35 adequately assessed patients, including 21 with dementia, clinical improvement and normal results of thyroid function tests were achieved, but five patients died with uncontrolled hyperthyroidism.

Conclusions: Hyperthyroidism in the elderly is usually due to autonomous thyroid nodules, and in about 20% of hospitalised patients may follow a contrast radiography procedure. The more common clinical features of hyperthyroidism occur frequently as unrelated symptoms in the elderly so that the diagnosis is often not apparent, particularly in the presence of cognitive impairment. As the response to standard biochemical treatment is rewarding, screening of the elderly with thyroid function tests should be done routinely.