Urinary calcium excretion in relation to kidney function in the adult

A study based on 55 hospital patients (age groups 40-59, 60-69, 70-79) demonstrated a significant correlation between the glomerular filtration rate (as expressed by endogenous creatinine clearance) and the mean urinary calcium concentration. Excluded were patients with thyroidal or hypophyseal disorders, osteoporosis, renal stones immobilizing conditions, or those treated with corticosteroids. The study patients had a normal fluid intake and did not receive any diuretics. The urinary calcium concentration test is less laborious and less liable to laboratory errors than the creatinine clearance test, which requires a 24-hour urine collection. Because of the gradual decrease in the glomerular filtration rate in the elderly, this test should be of value in geriatric practice.