* Patients with tumor-induced osteomalacia are characterized biochemically by hypophosphatemia,
hyperphosphaturia, inappropriately low or normal 1,25-dihydroxyvitamin D concentration, and increased alkaline phosphatase concentration.
Therefore, elevated blood glucose concentrations depolarize the brush border membrane for Pi and lead to lack of intracellular phosphate and
hyperphosphaturia. That this relationship also is applicable to human diabetes has been shown in juvenile diabetic patients.
described high urine carnitine concentration, aminoacyduria and
hyperphosphaturia in CF patient with coexisting renal tubules defect [19].
Hypophosphaturia was defined as a urinary phosphorus level less than 0.9 g/day, and hyperphosphaturia was defined as a urinary phosphorus level more than 1.3 g/day.
The frequency of metabolic abnormalities diagnosed in patients with recurrent calcium oxalate stones [n (%)] Male Female Total (n=91) (n=52) (n=143) Hyperoxaluria 62 (43.4) 30 (21.0) 92 (64.4) Low urinary volume 35 (24.4) 31 (21.7) 66 (46.2) Hypercalciuria 28 (19.5) 19 (13.3) 47 (32.8) Hypocitraturia 31 (21.7) 16 (11.2) 47 (32.8) Hypernatriuria 31 (21.7) 13 (9.1) 44 (30.8) Hypophosphaturia 24 (16.7) 14 (9.8) 38 (26.6) Primer 8 (5.6) 18 (12.6) 27 (18.9) hyperparathyroidism Hyperuricosuria 19 (13.3) 2(1.4) 21 (14.7) Hypomagnesuria 9 (6.3) 4 (2.8) 13 (9.1) Parathyroid adenoma 1 (0.7) 12 (8.4) 13 (9.1) Hyperphosphaturia 8 (5.6) 2(1.4) 10 (7.0) Secondary 1 (0.7) 1 (0.7) 2(1.4) hyperparathyroidism No abnormality 6 (4.2) 5 (3.5) 11 (7.7)
Hypercalciuria,
hyperphosphaturia, hypocitraturia and a high urinary pH are the main events that predispose RTA patients to develop renal stones.
One study reported that 22% of patients on tenofovir developed at least 2 out of 6 features of proximal tubular dysfunction such as hyperaminoaciduria, glycosuria in the presence of normoglycaemia, and
hyperphosphaturia. (5) Tenofovir may also cause renal failure.
Hyperaminoaciduria and
hyperphosphaturia occur as a result of 20HPT.
Oncogenic osteomalacia is an unusual syndrome that is characterized by multiple biochemical abnormalities, such as hypophosphatemia,
hyperphosphaturia, and low levels of plasma 1,25-dihydroxyvitamin D.
Hypophosphatemic rickets (HR) is a rare genetic disorder, which is characterised by diminished phosphate reabsorption in renal tubules leading to chronic
hyperphosphaturia and hypophosphatemia, which are associated with normal or low levels of 1,25(OH)2 Vitamin D3.
Laboratory Findings in these patients show hypophosphataemia with
hyperphosphaturia, normocalcaemia with normal or reduced calciuria [Jan and Levine, 2008].
Those authors described a clinical case of rickets, with hypophosphataemia and
hyperphosphaturia resistant to normal doses of vitamin D, and classified this metabolic condition as inheritable X-linked hypophosphataemic rickets (XLHR).
