Better tests for thyroid dysfunction

Measuring levels of thyroid stimulating hormone (TSH) may not be the best way to determine thyroid dysfunction, according to new data from Belgium.

Researchers looked at 832 hypothyroid patients seen in a private practice in Antwerp between May 1984 and July 1997.

Several indicators of hypothyroidism were considered, including the eight main clinical signs of the disorder as well as blood levels of several thyroid hormones. The researchers found that the eight main indicators of hypothyroidism led to an accurate diagnosis in 97 per cent of cases.

They also found that measurements of blood levels of 24 hour urine free triiodothyronine (T3) correlated well with clinical signs of hypothyroidism while other measurements, including traditional measurements of TSH, did not.

This finding has wide spread health implications since individuals who display symptoms of hypothyroidism often have normal levels of TSH in the blood. Thus, using TSH alone, many cases of subclinical hypothyroidism may go untreated until the disorder becomes acute (J Nutr Environ Med, 2000; 10: 105-13).