[Epidemiology of hypercalcemia. Significance of the determination of intact parathyroid hormone for differential diagnosis]

Characteristics of hospitalized patients with hypercalcemia in the province of Malaga: a longitudinal, retrospective, multicenter study

BACKGROUND AND OBJECTIVE

There are limited studies analyzing hypercalcemia in hospitalized patients. Our objectives were to describe the clinical characteristics of hospitalized patients with hypercalcemia, estimate its prevalence in the hospital setting, analyze the rate of correction of hypercalcemia, and identify prognostic variables.

MATERIALS AND METHODS

Observational, longitudinal, retrospective, and bicentric study. Adult patients admitted to two hospitals in Málaga (2014-2018) with a diagnosis of hypercalcemia were included. The minimum follow-up was 2 years or until death.

RESULTS

A total of 205 patients with hypercalcemia were included (incidence: 0.13%). The mean age (SD) was 68.2 (13.1) years, with a predominance of males (55.1%). The median (IQR) serum calcium at admission was 13.1 (11.8-14.6) mg/dl. The most common etiologies were neoplasms (75.1%), primary hyperparathyroidism, and medications (both 8.8%). The median (IQR) follow-up period was 5.1 (1.7-60.3) weeks. The most commonly used treatments were fluid therapy (86.8%), loop diuretics (70.9%), bisphosphonates (60.7%), and glucocorticoids (46.2%). The rate of correction of hypercalcemia was 65.2%, with a median (IQR) of 6 (3-10) days. The mortality rate was 81.5%. The median (95% CI) survival was 5.1 (3-7.3) weeks. Factors associated with higher mortality were advanced age, neoplastic etiology, serum calcium at admission, and failure to correct hypercalcemia.

CONCLUSIONS

Hypercalcemia in hospitalized patients is mainly due to neoplastic processes and is associated with high mortality. We observed a low rate of adherence to recommendations for the management of hypercalcemia.

Within-centre evaluation of hypercalcaemia discriminant functions 5 years after their development

Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time on their diagnostic capacity. Two populations, consisting of 257 and 129 patients with hypercalcaemia, were consecutively recorded, during six and three months respectively, 5 years apart under similar circumstances. The prevalence of hypercalcaemia was comparable in both populations, being 2.57 and 2.38% respectively (non-significant) (NS). The female/male ratio was 1.9 and 1.7 (NS). The discriminant functions correctly classified 81 and 80% of the women, respectively (NS) and respectively 75% and 64% of the men (NS) in the first and second recorded populations.

Primary hyperparathyroidism in Austria: results of an 8-year prospective study

Serum calcium determinations in 45,217 hospitalized patients during an 8 year period revealed sustained hypercalcemia in 124 (0.3%) patients. Further clinical and biochemical investigations established primary hyperparathyroidism (PHP) in at least 40 (32%) patients, an incidence of PHP of 89.6 +/- 41.5 per 100,000 patients per year. The incidence of PHP in males and females was 31.5 and 124.2 per 100,000, respectively. The highest incidence was found in females greater than 66 years of age (268.8 per 100,000). Nineteen (48%) patients showed classical symptoms of PHP, 14 (35%) patients were minimally symptomatic, and 7 (17%) patients were asymptomatic. The incidence and symptomatology of PHP in Austria is nearly the same as in other countries. Because of the multiple actions of parathyroid hormone in the body, PHP can cause debilitating symptoms but too often it remains undiagnosed clinically. Routine calcium determinations are very important and PHP must always be considered in the differential diagnosis, especially in minimally symptomatic patients.

[Pamidronate in the treatment of tumor-associated hypercalcemia]

After a 48-hour rehydration period 28 of 31 patients with cancer-associated hypercalcemia (serum calcium greater than or equal to 2.8 mmol/l) were treated intravenously with the bisphosphonate pamidronate. In three patients fluid repletion with 0.9% saline solution had already normalized serum calcium levels. Pamidronate was given in a single infusion on day 0, the dose of pamidronate adapted to the severity of hypercalcemia. If the serum calcium concentration was greater than or equal to 2.8 mmol/l on day 3, application of pamidronate was repeated. In all patients normocalcemia was restored; mean serum calcium decreased from 3.2 +/- 0.35 on day 0 to 2.15 +/- 0.32 on day 12. Hypercalcemia recurred in 11 patients, seven of these underwent pamidronate treatment according to the same therapeutical regimen. Normal calcium levels were attained in five cases. Side effects were of minor gravity: brief hyperthermia occurred in four patients and transient, asymptomatic hypocalcemia was noticed in nine cases.