1. What is Secondary Hyperparathyroidism?

Parathyroid glands in the neck produce parathyroid hormone, which controls the amount of calcium in the blood and within the bone. In Chronic Kidney Disease (CKD) patients, due to failing kidneys, a sufficiently active form of vitamin D is not produced. Further, phosphorus is not adequately excreted. Both processes lead to hypocalcemia (low calcium levels) and hence to secondary hyperparathyroidism.

2. What role do kidneys play in balancing minerals in     our body?

The kidneys play an important role in maintaining a healthy bone mass and structure by balancing calcium and phosphorus levels in the blood. Kidneys also ensure that vitamin D from sunlight and food becomes activated. The kidneys help keep calcium and phosphate balanced in the blood by:

• Removing extra phosphate from your blood
• Producing active Vitamin D needed for absorbing calcium from the gut and into the bone

3. Why are Calcium, Phosphate and Vitamin D important?

Calcium and phosphate are two minerals found in your bones and provide much of its strength. They keep other parts of your body healthy as well. Hence it is important that they remain at normal levels in the blood.

Calcium:
Calcium is needed for healthy bones and teeth. Most of the cells in the body need calcium to work properly. The body gets calcium mainly from food. Most calcium is used by the bones with the help of hormones.

Phosphate:
Phosphate is found in all the cells of the body and is important as a source of energy for the cells. Phosphate is also found in most foods and the body absorbs it from the gut with the help of Vitamin D. In people with Chronic Kidney Disease (CKD) a key symptom of high phosphate level is itching.

Vitamin D:
Vitamin D is made from cholesterol and sunlight and can be found in some foods. It is converted to its active form by the kidneys. If the kidneys do not work properly, then Vitamin D is not formed. Vitamin D is important because it is needed to absorb calcium from the gut. It is also needed to put calcium back into the bones and to lower the effect of parathyroid hormone.

4. How does Chronic Kidney Disease affect the balance?

Calcium and phosphate levels in the blood are kept in careful balance by your body's hormones. Chronic Kidney Disease (CKD) can upset this balance by causing phosphate to rise in the blood and calcium to fall. If calcium levels in the blood become too low, the parathyroid glands release a hormone called parathyroid hormone (PTH).

PTH draws calcium from the bones to raise blood calcium levels. Too much PTH in the blood will remove excessive calcium from the bones over a period of time. The constant removal of calcium weakens the bones. As kidney function slowly worsens calcium removal from bones can cause serious bone disease and, if ignored, the bones will eventually crack and crumble.

5. What are the complications of Secondary     hyperparathyroidism (SHPT)?

Secondary hyperparathyroidism could lead to the following complications if not treated:

• Mineral Bone Disorder (MBD)
• Vascular Calcification and Cardiovascular diseases

6. What is Mineral Bone Disorder in Chronic Kidney     Disease?

In Chronic Kidney Disease kidneys fail to maintain the proper levels of calcium and phosphorus in the blood. Since calcium and phosphorous are the main components of bone that provide its strength, any imbalance in these two essential components leads to improper mineralization and weakening of bones.  This could increase the chances of fracture, bone pain and disorder in bone mass.

7. Why there is risk of Vascular Calcification and     Cardiovascular disease in Secondary     Hyperparathyroidism patients?

In secondary hyperparathyroidism patients constant high level of PTH will remove excess amount of calcium leading to a condition called hypercalcemia (increased calcium). The high calcium level combines with phosphate and gets deposited in blood vessels and other soft tissues like heart and lungs. This will make the blood vessel very hard which may have an adverse impact on the flow of blood and consequently on the cardiovascular system.

6. How is CKD-MBD treated?

Controlling PTH levels prevents damage to bones. Usually overactive parathyroid glands are controllable with a change in diet, dialysis treatment or medication.
Treatment options available are:

1. Dietary restriction in Phosphorous
2. Controlling calcium levels in dialysis fluid
3. Calcium Salts
4. Non calcium based Phosphate binders like sevelamer
5. Vitamin D and their analogues
6. Newer treatment options like - Cinacalcet

7. What is Cinacalcet and its role?

In healthy human beings parathyroid hormone is released depending upon the level of calcium in blood. This happens through special kind of receptors called Calcium sensitizing receptors (CaSR) in the parathyroid gland. These receptors sense the calcium levels in the body and control the release of PTH from the gland. Low calcium increases PTH secretion while high calcium decreases PTH secretion.

In CKD patients, these receptors do not function properly and thus are unable to recognize the calcium level in the body. Due to this, these glands continuously secrete parathyroid hormone thus increasing PTH levels and hence increased calcium in the blood, thereby leading to Vascular Calcification.

Cinacalcet is a drug which stimulates these calcium receptors and sensitizes them to serum calcium. This in turn will suppress PTH production and help in managing adequate calcium and phosphorus, thus helping to reduce various complications related to Mineral Bone Disorder.

8. What is CeRACaL?

CeRACaL is the brand name of Cinacalcet drug marketed by Biocon. CeRACaL helps control high Parathyroid hormone levels by stimulating calcium sensitizing receptors in parathyroid gland. It also helps in maintaining the calcium and phosphorus levels and in preventing long term complications of secondary hyperparathyroidism.

9. What is the dosage for CeRACal?

Dosage will vary from 30mg to 180mg tablet depending upon the PTH, calcium and other clinical parameters.