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 E N T (Ear Nose & Throat)

september 2012
PTH:High Or Low, It’s A Maze
Dr Ambrish Mithal & Dr Parjeet Kaur
 
Parathyroid glands are small pea sized glands of the endocrine or hormonal system, which are located in the neck behind the thyroid gland. The thyroid gland and parathyroid glands, although situated very close to each other, are very different.

Parathyroid glands make a hormone called parathyroid hormone (PTH) that maintains the level of calcium in the blood. PTH raises blood calcium by various mechanisms. It derives calcium from the bones into the blood, increases calcium absorption from the intestine, High Or Low, It’s A Maze Dr Ambrish Mithal & Dr Parjeet Kaur and reduces calcium losses through the kidneys.

In hyperparathyroidism, parathyroid glands produce and release excess parathyroid hormone, a condition called as primary hyperparathyroidism. Usually this is caused by tumours of the parathyroid glands. Sometimes, medical conditions such as kidney failure and vitamin D deficiency too can cause parathyroid glands to produce too much PTH; this is termed secondary hyperparathyroidism. In India, hyperparathyroidism secondary to vitamin D deficiency is very common.

Symptoms & Complications
Primary Hyperparathyroidism:
Many people who have primary hyperparathyroidism do not experience any symptoms. Symptoms, when they do show up, are only non-specific such as weakness or tiredness or generalised body ache and pains. There will however be symptoms directly related to high blood calcium levels.
They include:
  • Nausea and vomiting
  • Abdominal pain
  • Constipation
  • High blood pressure
  • Increased thirst
  • Increased urination
  • Confusion and poor memory
  • Kidney stones
In the state of hyperparathyroidism, the bones face an imbalance in the amount of calcium that is derived out of them into the blood stream and the amount they actually receive to stay functionally strong. The former is more than the latter and the bones hurt, go weak, break easily and are slow to heal.

Secondary Hyperparathyroidism:
Secondary hyperparathyroidism arises from other medical conditions and its symptoms vary accordingly. Symptoms noticed in the common case where it is secondary to vitamin D deficiency are:
  • Bone and joint pain
  • Muscle weakness with difficulty in getting up from sitting or lying position.
  • Limb deformities, a condition called rickets in children.
  • In severe cases, due to low calcium level in the blood, symptoms develop as tingling and numbness of hands and feet and muscle spasms.
  • Symptoms can relate to chronic kidney failure, if that is the cause of secondary hyperparathyroidism.
Diagnosis Of Hyperparathyroidism
  • High level of PTH is the hallmark of hyperparathyroidism. An assessment of the level of calcium present in the blood is necessary to confirm whether it is a case of primary or secondary hyperparathyroidism.
  • In primary hyperparathyroidism, the calcium level in the blood is high, whereas in secondary hyperparathyroidism the calcium level in the blood is normal or low.
  • Primary hyperparathyroidism is suspected when a high level of calcium is found in the blood during a routine blood test. It is often the case, because generally the condition is non symptomatic.
  • Other tests that may be done are bone mineral density test to assess bone loss and the risk of fractures, and abdominal ultrasound to check on kidney stones if any.
  • A special scan called MIBI scan can localize a tumour in the parathyroid gland. Ultrasound and MRI of the neck are additional tests for the same.
  • In secondary hyperparathyroidism due to vitamin D deficiency, vitamin D level in the blood will be low.
Treatment Of Hyperparathyroidism

Surgical removal
of the enlarged parathyroid gland (or glands) is the main treatment for primary hyperparathyroidism. The rate of cure is 95 per cent. Symptoms that are caused by high calcium level in the blood will ease in the first month of surgery. For a short time after surgery, blood calcium level may also be too low. This problem is treated with calcium and vitamin D supplements.

Medical management is the option when these patients resist surgery or when patients do not meet the guidelines for surgery. Treatment aims to improve bone density (thickness) and correct the calcium level in the blood. Various drugs may be used. These include a group of drugs called bisphosphonates. Another drug called cinacalcet also helps to reduce calcium and PTH levels.

A mild case of hyperparathyroidism can be monitored without any treatment. It includes regular tests to check blood calcium level, blood pressure, kidney function and also DXA bone scanning to assess bone density.

Unlike primary hyperparathyroidism, medical management is the mainstay of treatment for secondary hyperparathyroidism. It involves treatment for underlying conditions like vitamin D deficiency and chronic kidney disease.

DOs and DON’Ts In Managing Primary Hyperparathyroidism
  • DO tell your doctor if you have a family history of parathyroid or other endocrine tumours.
  • DO drink plenty of water to prevent high blood calcium levels. Dehydration will increase your calcium level.
  • DO find an experienced surgeon for your operation.
  • DO see your doctor regularly and undergo the necessary tests if no surgery is planned.
  • DO call your doctor if you notice muscle spasms, face twitching, or numbness around the lips after surgery on the parathyroid glands. These symptoms of a very low blood calcium level are due to a low level of PTH and need attention right away.
  • DON’T take calcium supplements unless your doctor approves.
Dr Ambrish Mithal is Chairman, Endocrinology & Diabetes, Medanta - The Medicity, Gurgaon.
Dr Parjeet Kaur is Associate Consultant, Endocrinology & Diabetes, Medanta - The Medicity, Gurgaon.