Correlation of serum-adjusted calcium with ionized calcium over a 24-h period in patients with adult growth hormone deficiency before and after growth hormone replacement

Abstract

Background: Difficulties associated with measuring ionized calcium in clinical practice have led to the use of total calcium, with or without adjustment for albumin concentration, as an estimate of calcium metabolism. We examined the correlation between ionized and total/adjusted calcium over a 24-h period in patients with adult growth hormone deficiency (AGHD), a group of patients with previously reported alterations in calcium metabolism. Methods: Four patients with AGHD were consented to the study. They were hospitalized for 24 h where half-hourly blood samples were collected for ionized calcium, total calcium, albumin and creatinine, before and one month after the commencement of growth hormone replacement. Total calcium concentration was adjusted for serum albumin. Results: Strong correlations were found between ionized calcium and adjusted calcium (r 2 ¼ 0.840 and 0.766 for visits 1 and

Effect of Oral Phosphate and Alendronate on Bone Mineral Density When Given as Adjunctive Therapy to Growth Hormone Replacement in Adult Growth Hormone Deficiency

“…Serum calcium was adjusted for albumin as previously described (25). Serum adjusted calcium (ACa) has been shown to correlate strongly with ionized calcium in subjects with calcium and albumin within the reference range (25), and we have previously shown a strong correlation between ACa and ionized calcium in patients with AGHD throughout the day and night (26).…”