Assessment of the pathogenetic role of physical exercise in renal stone formation
| Autor: | Ming Chue Hsu, Sanjay Nigam, Peter G. Snell, Charles Y.C. Pak, Khashayar Sakhaee |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Adult
Male medicine.medical_specialty Endocrinology Diabetes and Metabolism Clinical Biochemistry Physical Exertion Calcium oxalate chemistry.chemical_element Urine Calcium Biochemistry Oxalate chemistry.chemical_compound Kidney Calculi Endocrinology Internal medicine medicine Humans Kidney Biochemistry (medical) Urinary calcium medicine.anatomical_structure chemistry Renal physiology Uric acid Female Crystallization Blood Chemical Analysis |
| Zdroj: | The Journal of clinical endocrinology and metabolism. 65(5) |
| ISSN: | 0021-972X |
| Popis: | The effects of moderate physical exercise (performed on a bicycle ergometer to 70-75% of maximum oxygen consumption) without fluid replenishment on urinary chemistries and crystallization of kidney stone-forming substances were compared to those of rest in six normal subjects. Moderate physical exercise significantly decreased urinary pH [from 6.35 +/- 0.32 (+/-SD) to 5.79 +/- 0.33; P less than 0.05] and citrate [from 121.1 +/- 63.5 to 88.2 +/- 44.4 mg/6-h period from initiation of physical exercise; P less than 0.05 (630 +/- 331 to 459 +/- 231 mumol/6 h)], owing to induced metabolic acidosis. The total renal excretion of stone-forming constituents decreased [for example, calcium from 31.2 +/- 15.8 to 21.4 +/- 6.5 mg/6 h (0.8 +/- 0.4 to 0.5 +/- 0.2 mmol/6 h), phosphorus from 155 +/- 42 to 127 +/- 27 mg/6 h (5.01 +/- 1.4 to 4.1 +/- 0.9 mmol/6 h), and uric acid from 172 +/- 60 to 117 +/- 13 mg/6 h (1.0 +/- 0.4 to 0.7 +/- 0.1 mmol/6 h), each P less than 0.05], probably due to extracellular volume contraction (from sweating) and enhanced renal tubular reabsorption. However, the urinary concentration of stone-forming constituents significantly increased during and after moderate exercise because of the fall in urinary volume from 847 +/- 312 to 290 +/- 36 ml/6 h (P less than 0.01). Thus, urinary calcium oxalate saturation increased significantly from 2.62- to 6.68-fold saturation (P less than 0.01). The urinary undissociated uric acid concentration significantly rose [from 31.6 +/- 24.8 to 125.7 +/- 60.3 mg/L (0.19 +/- 0.15 to 0.76 +/- 0.36 mmol/L; P less than 0.01)], due to higher total uric acid concentration and reduced urinary pH. The saturation of calcium phosphate (brushite) did not change significantly, because the rise in urinary calcium concentration was compensated for by reduced phosphate dissociation (from lower urinary pH). The propensity for spontaneous precipitation of calcium oxalate was greater after exercise, as less soluble oxalate was required to elicit nucleation of calcium oxalate [58.0 +/- 21.2 to 49.0 +/- 16.4 mg/L (644 +/- 236 to 544 +/- 182 mumol/L); P less than 0.05]. The results suggest that moderate physical exercise, without increased fluid intake to compensate for excessive sweating, may cause the crystallization of uric acid and calcium oxalate in urine and may enhance the risk of the formation of renal stones composed of these salts. |
| Databáze: | OpenAIRE |
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