Thyroid Research Thyroid Research Archive Hypothyroidism

Central hypothyroidism is common in patients with hypopituitarism

(March 2002)

The background of the study. The clinical manifestations, hormonal deficiencies, and causes of hypopituitarism are diverse, and little is known about its frequency in the general population.

How the study was done. The number of patients with hypopituitarism who were 18 years and older in the registry of patients at the General Hospital of Vigo, in northwestern Spain, was determined from 1992 to 1999. Most, if not all, patients with pituitary disease in the region are referred to this hospital. There were 137,465 and 151,587 adults living in the area in 1992 and 1999, respectively. Pituitary hormone secretion was assessed by standard methods, and the diagnosis of hypopituitarism was based on the presence of a deficiency of one or more pituitary hormones.

The results of the study. In 1992 there were 40 patients with hypopituitarism in the registry (29 per 100,000 people). In 1999 there were 69 patients (46 per 100,000 people). From 1993 to 1999 there were 4 to 9 new cases per year; the mean annual incidence rate was 4.2 per 100,000 people per year. The most common causes of hypopituitarism in both 1992 and 1999 were hormone-secreting pituitary tumors, nonsecreting pituitary tumors, and hypopituitarism of unknown cause.

Among the 69 patients in 1999 the proportions with 1, 2, 3, 4, 5, and 6 hormonal deficiencies were, respectively, 21 percent, 15 percent, 23 percent, 19 percent, 15 percent, and 7 percent. The most frequent deficiency was that of gonadotropins (87 percent), followed by thyrotropin (TSH; 64 percent), corticotropin (62 percent), and growth hormone (61 percent). The frequency and types of deficiency were similar in the patients with tumors and those with other disorders.

The conclusions of the study. In this region of Spain, the annual incidence of hypopituitarism remained constant for 7 years. The majority of patients had a pituitary tumor, and TSH deficiency-and therefore hypothyroidism-was common.

The original article. Regal M, Paramo C, Sierra JM, Garcia-Mayor RV. Prevalence and incidence of hypopituitarism in an adult Caucasian population in northwestern Spain. Clin Endocrinol 2001;55:735-40.