Calcium screening in recurrent stone formation/bony fractures -Hyperparathyroidism
When the parathyroid glands become overactive they start producing too much of the parathyroid hormone. This disorder is known as hyperparathyroidism and is characterized by hypercalcemia. Surgery is the only method of total cure for a parathyroid disorder. If left untreated, the disorder leads to excess calcium deposition in the body. This results in recurrent stone formation in the kidneys and bone ailments.
The incidence of primary hyperparathyroidism (PHPT) is highest between 50 and 60 years of age, affecting 2% of the population aged 55 years or older, being 2–3 times more likely in females.
Occurrence of Nephrolithiasis in PHPT
In hyperparathyroidism, the PTH levels increase, leading to the rise in serum calcium concentration. Renal calcifications lead to Nephrolithiasis( kidney stones) and Neprocalcinosis(diffuse calcium-phosphate deposition in parenchyma) which causes impaired renal functions. However, with the improvement in the screening tools for the diagnosis of PHPT levels, patients can be diagnosed with the disorder and treated on time, while still asymptomatic. Patients who develop kidney stones due to primary hyperparathyroidism can have normal levels of urinary calcium excretion. Patients with kidney stones due to hyperparathyroidism can have one or two large stones instead of numerous small stones developed over many years.
Note: The longer a person has had elevated calcium levels, the higher the chance of developing kidney stones.
Screening for hyperparathyroidism for kidney stone patients
Calcium levels in patients with hyperparathyroidism can fluctuate. Hence, for kidney stone patients, even if you have normal calcium levels, it is still recommended to get tested for hyperparathyroidism. If the disease is diagnosed, the tumor is removed and the stone activity gets reduced. The stone recurrence is said to get reduced by 30% at 5 years, which is significantly lesser than the incidence before an operation.
If serum calcium is elevated, the PTH and phosphorus levels are measured. In hyperparathyroidism, the PTH levels are either normal-high or increased, while the phosphorus levels are reduced.
While screening for hyperparathyroidism is simple, the hypercalcemia may be intermittent. This makes it mandatory to get serum calcium levels tested from time to time for hyperparathyroidism. Consult your doctor for Calcium, Phosphorus & PTH test if you are diagnosed with kidney stones.