Prevalence and incidence of hypopituitarism in an adult Caucasian population in northwestern Spain.

OBJECTIVE: To determine the prevalence and incidence of hypopituitarism in the general population.

POPULATION: The study population comprised an average population sample of 146,000 adult inhabitants in South Galicia (northwestern Spain). The Medical Register of the General Hospital of Vigo ensured virtually complete case ascertainment for diagnosed hypopituitarism in this sample population. Only patients residing in the study area were included. The diagnosis of hypopituitarism was based on baseline and hormonal dynamic tests.

DESIGN: The study comprised two cross-sectional surveys, the first from January to December 1992 and the second from January to December 1999, together with a longitudinal survey performed between January 1993 and December 1999.

MAIN RESULTS: In the first survey the prevalence of hypopituitarism was 29/100,000 (CI, 19.88-37.72), without sex differences. In the second survey, the prevalence observed was higher than in the first, 45.5/100,000 (CI, 34.92-56.08). In the second survey, which included almost all cases registered in the first study, the cause of hypopituitarism was a pituitary tumour in 61%, a non-pituitary tumour in 9% and a non-tumour cause in 30%. Around 50% of patients had 3-5 pituitary hormonal deficiencies, with LH/FSH being the most prevalent. Patients with tumour-induced hypopituitarism showed a tendency to suffer GH deficiency more frequently than those due to non-tumour causes. In the longitudinal study with a population of 1,020,764 people-years of observation, the average annual incidence rate of hypopituitarism was 4.21 cases/100,000 (CI, 2.95-5.47), with this incidence being similar for both sexes. The annual incidence of hypopituitarism remained stable during the study period.

CONCLUSION: We present for the first time data on the prevalence and incidence of hypopituitarism in the general adult population. These patients showed a tendency to suffer LH/FSH deficiency as the most prevalent hormone deficit. Furthermore, patients with hypopituitarism due to a tumour or its treatment showed a greater tendency to suffer GH deficiency than those with a non-tumour cause. These data may be useful for producing a rational programme for patients suffering from this condition and also for comparison with future data in our country and elsewhere in the world.