Secondary Hyperparathyroidism

OVERVIEW

Secondary Hyperparathyroidism (SHPT) is a multifactor condition for patients with chronic kidney disease (CKD) associated with morbidity and mortality. In the early stages of CKD, SHPT is characterized by the increased synthesis and secretion of parathyroid hormone (PTH) and the proliferation of gland cells called parathyroid hyperplasia which itself is a clinical challenge. In SHPT, serum fibroblast growth factor-23 (FGF-23) increases serum phosphorus levels, suppress the synthesis of activated vitamin D, 1α,25-dihydroxyvitamin D and results to hypocalcemia condition. As a result, decreased expression of the vitamin D and calcium-sensing receptors expressed on the parathyroid cells can worsen secondary hyperparathyroidism (SHPT). Prolonged SHPT is often associated with disturbances of bone turnover, as well as visceral and vascular calcifications, which are responsible for cardiovascular morbidity and mortality. Despite improvements in medical treatment, surgical treatment of SHPT is often necessary, especially in refractory cases. Renal transplantation is a therapeutic alternative but is frequently followed by the persistence of hyperparathyroidism.

FACTORS

Factors that may result in secondary hyperparathyroidism include:

Chronic kidney failure. Chronic kidney failure is the most common cause of secondary hyperparathyroidism. The kidneys convert vitamin D into a form that your body can use. If your kidneys work poorly, usable vitamin D may decrease and calcium levels drop. This causes parathyroid hormone levels to go up and causes SHPT.
Severe calcium deficiency. Your body may not get enough calcium from your diet, often because your digestive system doesn't absorb the calcium from food. This is common after intestinal surgery, including weight loss surgery.
Severe vitamin D deficiency. Vitamin D helps maintain appropriate calcium levels in the blood. It also helps your digestive system absorb calcium from your food. Your body produces vitamin D when your skin is exposed to sunlight. You also get some vitamin D in food. If you don't get enough vitamin D, then calcium levels may drop.

DIAGNOSIS

Blood tests: To measure calcium, vitamin D, phosphorus and parathyroid hormone levels and to analyse how well your kidneys are working Urine tests: To see how much calcium is in your urine and how well your kidneys are working

X-rays: To see if you have kidney stones or broken bones

Ultrasound: To make images of your kidneys or parathyroid glands, such as to see if your parathyroid glands have grown larger

Bone density scan: To see how strong your bones are.

Tc99 sestamibi scan: Scan of head, neck and upper thorax is the most commonly used test for localizing parathyroid adenomas.

SIGN AND SYMPTOMS

1. Bone and mineral disorders	5. Bone pain, bone deformation and fractures
2. Cardiovascular complications	6. Chest wall deformity and kyphoscoliosis
3. Calciphylaxis	7. Red-eye syndrome, and intense pruritus.
4. Muscle pain	8. Kidney stone, CKD and loss of apetite

TREATMENT

Dialysis/ Renal Transplant: If SHPT is caused by kidney failure, then doctors treat kidney failure with dialysis or a kidney transplant.
Antibiotics: Take medicines, including Vitamin D or calcium supplements which helps your body to absorb calcium and calcimimetics, which tell your parathyroid glands to make less PTH.
Surgery: Have surgery to remove one or more of your parathyroid glands