[Tubular dysfunction in renal lithiasis: cause or consequence?].
To investigate whether overall tubular dysfunction is encountered in a particular subgroup of patients with urolithiasis, the following parameters of renal tubular function have been measured in fasting morning urine in 124 male stone formers: excretion of lysozyme and gamma-glutamyl transpeptidase (gamma-GT), fractional excretion (FE) or glucose, insulin, bicarbonate after an alkali load, and theoretical phosphate threshold (TmP/GFR). The following have been diagnosed: primary hyperparathyroidism (n = 3), medullary sponge kidneys (n = 5), hyperuricemia (n = 8), cystinuria (n = 1), struvite nephrolithiasis (n = 2), idiopathic hypercalciuria of the absorptive (n = 16), dietary (n = 46) or renal (n = 5) type, and normocalciuric idiopathic urolithiasis (n = 38). Urinary excretion of lysozyme and of gamma-GT were elevated in 14% and 21% of patients respectively; FE glucose and FE insulin were elevated in 6% and 8% of patients respectively. In 62% of the patients TmP/GFR was below 0.95 mmol/l and in 52% of the patients FE HCO3 after alkali load was above normal. The findings show that a large number of stone formers have signs of renal tubular dysfunction; apparent renal leaks of phosphate and of bicarbonate are the most frequently encountered defects; while they are not specific for a given etiologic group of patients, they have been found in each group. The latter observation suggests that nephrolithiasis itself can damage renal tubular function.
Jaeger
P
P
Portmann
L
L
Burckhardt
P
P
D000328:Adult; D001639:Bicarbonates / Q000652:urine; D006029:Glycosuria / Q000175:diagnosis; D006801:Humans; D007328:Insulin / Q000652:urine; D007669:Kidney Calculi / Q000503:physiopathology*; D007684:Kidney Tubules / Q000503:physiopathology*; D008297:Male; D009113:Muramidase / Q000652:urine; D005723:gamma-Glutamyltransferase / Q000652:urine
D001639:Bicarbonates; D007328:Insulin; D005723:gamma-Glutamyltransferase; D009113:Muramidase
Dysfonction tubulaire dans la lithiase rénale: cause ou conséquence?