Secondary hyperparathyroidism is associated with increased risk of hospitalization or death in elderly adults living in a geriatric institution.

BACKGROUND

The presence of secondary hyperparathyroidism is very frequent in the elderly population living in geriatric institutions. It has been associated with an increased mortality rate in previous studies.

OBJECTIVES

To evaluate the association of secondary hyperparathyroidism with mortality or hospitalization or both (combined outcome) during a 6-month period in individuals living in geriatric institutions.

METHODS

A cohort of 100 individuals aged between 65 and 102 years living in geriatric institutions in the city of Porto Alegre, Brazil, was prospectively studied. Serum levels of 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), albumin, total calcium, phosphorus, magnesium, creatinine and alkaline phosphatase were measured. The glomerular filtration rate (GFR) was calculated using the Cockcroft-Gault equation. Secondary hyperparathyroidism was defined as serum PTH levels higher than 48 pg/ml and normal or reduced serum calcium levels. The deaths were verified by means of death certificates and hospitalization by the discharge summaries provided by the Brazilian health system hospitals.

RESULTS

Fifty-eight percent of the individuals had secondary hyperparathyroidism, defined as serum PTH >48 pg/ml and normal or low serum calcium. Mean serum 25(OH)D levels were 12.5 +/- 8 ng/ml. The odds ratio of an individual with secondary hyperparathyroidism to die, to be hospitalized or to have the combined outcome within 6 months was 6.6 [confidence interval (CI) 95% 0.8-54.6; p = 0.07], 10.7 (CI 95% 1.3-85.9; p = 0.007) and 5.20 (CI 95% 1.10-27.7; p = 0.04), respectively. Secondary hyperparathyroidism and body mass index were independently associated with the combined outcome, after correction for the GFR and 25(OH)D.

CONCLUSION

Secondary hyperparathyroidism could be an important prognostic factor for individuals living in geriatric institutions.