ADVERTISEMENT

Primary hyperparathyroidism: Labs to order, Tx to consider

The Journal of Family Practice. 2018 November;67(11):E16-E21
November 1, 2018|Family Medicine
Padmaja Sanapureddy, MD;Vishnu Vardhan Garla, MD;Mallikarjuna Reddy Pabbidi, DVM, PhD
Author and Disclosure Information

Department of Primary Care and Medicine, G.V. (Sonny) Montgomery VA Medical Center, Jackson, Miss (Dr. Sanapureddy); University of Mississippi Medical Center, Jackson, Miss (Drs. Garla and Pabbidi)
sanapureddypadmaja@gmail.com

The authors reported no potential conflict of interest relevant to this article.

Unexplained kidney stones, osteoporosis, or certain subtle clues may point to hyperparathyroidism. These tests and imaging options can help you to be sure.

PRACTICE RECOMMENDATIONS

› Evaluate suspected cases of primary hyperparathyroidism (PHPT) with serum total calcium, parathyroid hormone (PTH), creatinine, and 25-hydroxy vitamin D levels. A

› Consider 24-hour urine measurement of calcium and creatinine in patients undergoing evaluation for possible PHPT. A

› Obtain bone densitometry at the spine, hip, and distal radius in patients with PHPT. A

Strength of recommendation (SOR)

A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series

Serum 25(OH) vitamin D

Vitamin D levels are normal in PHPT and normocalcemic PHPT. However, measuring 25(OH) vitamin D in all patients with suspected PHPT is recommended to evaluate for secondary hyperparathyroidism that is due to hypocalcemia or renal failure, which can occur concomitantly with PHPT.

Patients with primary hyperparathyroidism can present with nonspecific symptoms such as weakness, fatigue, anorexia, polyuria, polydipsia, bone and joint pain, and mild cognitive or neuromuscular dysfunction.

Normocalcemic PHPT can be differentiated from secondary hyperparathyroidism of chronic kidney disease by measuring the 1,25(OH)2 vitamin D level; it will be low in secondary hyperparathyroidism.4

Serum 1,25(OH)2 vitamin D

1,25(OH)2 vitaminD levels are elevated in about one-third of patients with PHPT, as PTH stimulates the conversion of 25(OH) vitamin D to 1,25(OH)2 vitamin D.13 Although this is not a routine test, it is useful in the evaluation of parathyroid-independent hypercalcemia caused by granulomatous disease, such as sarcoidosis where there is an autonomous production of 1,25(OH)2 vitamin D leading to hypercalcemia.14

 

Serum creatinine and estimated glomerular filtration rate

Serum creatinine (Cr) helps assess renal function. Reduction in serum Cr clearance to <60 mL/min with no other underlying cause is an indication for parathyroidectomy.10

Serum phosphorous

PTH increases the excretion of phosphorous by inhibiting reabsorption from the proximal tubule. Therefore, serum phosphorus tends to be in the lower range of normal in PHPT, but hypophosphatemia is present in less than a quarter of patients.4

Continue to: 24-hour urinary Ca2+

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT