Predictive score estimates risk of developing hypothyroidism, hyperthyroidism

Researchers have developed a predictive score to estimate the five-year risk of developing hypothyroidism or hyperthyroidism in women with relatives who have autoimmune thyroid disease.

In a prospective, observational cohort study researchers from the University of Amsterdam and Medical University Lubeck in Germany evaluated 790 healthy women aged 18 to 65 years with at least one first- or second-degree relative with a confirmed autoimmune thyroid disease.

The researchers measured serum thyrotropin, free thyroxine and thyroid peroxidase antibody levels and obtained information on family history. Thyroid function was examined yearly for five years.

Over the five years, 38 hypothyroid and 13 hyperthyroid events occurred, yielding a cumulative rate of 7.5%, with a mean annual rate of 1.5%.

In a level-dependent relationship, baseline thyroid-stimulating hormone and thyroid peroxidase antibodies were independent risk factors for events. Family background was also an independent risk factor, with the greatest risk among women with two relatives with Hashimoto’s disease.

Using the Thyroid Events Amsterdam Score, the researchers estimated events by weighing TSH, thyroid peroxidase and family history to their relative risks: low (1-7), medium (8-10), high (11-15) and very high (16-21). According to the researchers, the predicted Thyroid Events Amsterdam scores correlated with the observed event rates of 2.7% (low), 14.6% (medium), 27.1% (high) and 76.9% (very high).

“In view of the small number of observed events, independent validation of the Thyroid Events Amsterdam Score is called for,” the researchers wrote.

Arch Intern Med. 2008;168:1657-1663.