Age and sex influences on urine calcitonin-like immunoreactivity in normal subjects.
Calcitonin-like immunoreactivity levels were determined in urine specimens in 585 normal subjects of various ages. Urine calcitonin-like immunoreactivity (uCTi) was measured by the midportion-specific radioimmunoassay after extraction of urine by gel chromatography on a 0.8 X 20 cm column of Bio Gel P-2. In 197 males and 169 females below 20 years old, significant negative correlations between the age and uCTi were observed (male: r = -0.684, female: r = -0.690). In 75 males and 80 females above 41 years, however, no significant correlation was observed between age and uCTi. The high level of uCTi in children could be explained by high levels of circulating calcitonin, associated with rapid bone growth; however the uCTi level in the elderly may not reflect the physiological significance of calcitonin for them because of a suspected age-related decrease in renal clearance of uCTi in the elderly.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002116:Calcitonin / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012737:Sex Factors
D002116:Calcitonin