title: Comparative study of the circadian rhythmicity in the urinary concentration of glycosaminoglycans in patients of calcium oxalate nephrolithiasis and in healthy adults.
abstract: Glycosaminoglycans (GAGs) are potent inhibitors of calcium oxalate crystallisation and/or crystal aggregation. Urinary concentration of GAGs has been shown to vary during 24 h; therefore, circadian rhythmicity in urinary concentration of GAGs was investigated in 33 healthy male adults in the age group of 20-40 years and in 27 male patients of a similar age group with calcium nephrolithiasis. Three-hourly urine samples were collected for 24 h beginning from 00.00 h for estimation of urinary concentration of GAGs. The data of each patient was analysed by single cosinor rhythmometry and population mean-cosinor rhythmometry was then applied to each group. Twenty-four-hour urinary excretion of GAGs was significantly less in renal calculus patients (16.867 +/- 5.89 mumol) than in healthy subjects (22.588 +/- 5.32 mumol; p less than 0.001). A statistically validated circadian rhythm in urinary concentration of GAGs was demonstrated in both the groups. However, the amplitude-acrophase test revealed a significant difference between the two groups (F2,57 = 8.305; p less than 0.001); the amplitude was 2.354 mumol/l in patients with nephrolithiasis, whereas the amplitude was 7.028 mumol/l in healthy adults. The mesor test also revealed a significant difference in the 3-hour urinary concentration of GAGs between the two groups (18.536 mumol/l in healthy adults vs. 9.728 mumol/l in patients with nephrolithiasis). Thus in patients with nephrolithiasis, not only is the 24-hour urinary excretion of GAGs significantly low but the 3-hourly urinary concentration of GAGs is also significantly decreased as compared to healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors: H
authors: H
authors: Sidhu
authors: S K
authors: SK
authors: Thind
authors: R
authors: R
authors: Nath
authors: S
authors: S
authors: Vaidyanathan
authors: A K
authors: AK
authors: Hemal
authors: A K
authors: AK
authors: Mandal
authors: K
authors: K
authors: Krishan
mesh_terms: D000328:Adult; D002129:Calcium Oxalate / Q000032:analysis*; D002940:Circadian Rhythm; D006025:Glycosaminoglycans / Q000652:urine*; D006801:Humans; D007669:Kidney Calculi / Q000032:analysis / Q000652:urine*; D008297:Male
chemical_list: D006025:Glycosaminoglycans; D002129:Calcium Oxalate