Abstract
Purpose:
Primary hyperparathyroidism is a common cause of hypercalcemia with resulting hypercalciuria and a subset of these patients with primary hyperparathyroidism present with urolithiasis. We evaluated the metabolic stone profile in patients presenting for parathyroid surgery and determined whether there were differences between those with and without a history of urinary stones.
Materials and Methods:
A total of 60 patients with primary hyperparathyroidism presenting for parathyroid surgery were prospectively enrolled in the study, of whom 54 completed a preoperative 24-hour urine collection. Of these 54 patients 27 completed an additional postoperative 24-hour urine collection. We compared preoperative metabolic urinary profiles and serum calcium in patients with primary hyperparathyroidism with and without a history of urolithiasis. In addition, we compared changes in urine metabolic profiles that occurred after successful parathyroid surgery.
Results:
There were no significant differences in preoperative 24-hour urine metabolic profiles or serum calcium between patients who had primary hyperparathyroidism with and without a history of urolithiasis. Compared to preoperative levels after successful parathyroid surgery there were significant decreases in serum calcium (10.8 to 9.3 mg/dl, p <0.001), urinary calcium (319 to 156 mg per day, p <0.01) calcium oxalate supersaturation (8.6 to 5.7, p = 0.016) and calcium phosphate supersaturation (1.6 to 0.9, p = 0.002) in the 27 patients who completed a postoperative 24-hour urine collection.
Conclusions:
Other etiological factors must exist that cause some patients with primary hyperparathyroidism to form stones, while most never have stones despite profound hypercalcemia and hypercalciuria. Routine 24-hour urine evaluation cannot predict which patients with primary hyperparathyroidism will have kidney stones.
References
- 1 : Pathophysiology and management of calcium stones. Urol Clin North Am2007; 34: 323. Google Scholar
- 2 : The role of Randall's plaques in the pathogenesis of calcium stones. J Urol2007; 177: 31. Link, Google Scholar
- 3 : The primary stone event: a new hypothesis involving a vascular etiology. J Urol2004; 171: 1920. Link, Google Scholar
- 4 : Nephrolithiasis and bone involvement in primary hyperparathyroidism. Am J Med1990; 89: 327. Google Scholar
- 5 : Primary hyperparathyroidism. J Urol1989; 141: 723. Link, Google Scholar
- 6 : Kidney stones as a manifestation of hypercalcemic disorders: Hyperparathyroidism and sarcoidosis. Urol Clin North Am2000; 27: 275. Google Scholar
- 7 : Risk of renal stone events in primary hyperparathyroidism before and after parathyroid surgery: controlled retrospective follow up study. BMJ2002; 325: 807. Google Scholar
- 8 : Primary hyperparathyroidism: renal calcium excretion in patients with and without renal stone disease before and after parathyroidectomy. World J Surg2002; 26: 532. Google Scholar
- 9 : Renal stones and primary hyperparathyroidism: natural history of renal stone disease after successful parathyroidectomy. World J Surg1999; 23: 173. Google Scholar
- 10 : The importance of circulating 1,25 dihydroxyvitamin D in the pathogenesis of hypercalciuria and renal stone formation in primary hyperparathyroidism. N Engl J Med1980; 302: 421. Google Scholar
- 11 : Cohort study on effects of parathyroid surgery on multiple outcomes in primary hyperparathyroidism. BMJ2003; 327: 530. Google Scholar
- 12 : A 10-year prospective study of primary hyperparathyroidism with or without parathyroid surgery. N Engl J Med1999; 341: 1249. Google Scholar
- 13 : When and how to evaluate a patient with nephrolithiasis. Urol Clin North Am2000; 27: 203. Google Scholar
- 14 : Asymptomatic primary hyperparathyroidism. J Bone Miner Res1991; 6: 103. Google Scholar
- 15 : Primary hyperparathyroidism: A review of the long-term surgical and nonsurgical morbidities as a basis for a rational approach to treatment. Arch Intern Med1989; 149: 789. Google Scholar
- 16 : Predictive value of kidney stone composition in the detection of metabolic abnormalities. Am J Med2003; 115: 26. Google Scholar
Departments of Urology and Surgery (WW, QYD), University of California-San Francisco, San Francisco, California
