Hyperparathyroidism

Hyperparathyroidism is a condition where the parathyroid glands, which are four small glands located in the neck near the thyroid, produce too much parathyroid hormone (PTH). PTH is responsible for regulating calcium, phosphorus, and magnesium levels in the blood and bones. When the parathyroid glands become overactive, they release excessive PTH, leading to elevated calcium levels in the blood, a condition known as hypercalcemia.

This condition can have significant implications for bone health, kidney function, and overall metabolism. To better understand hyperparathyroidism, this blog will delve into its types, causes, symptoms, diagnosis, treatment options, and long-term management strategies.

Types of Hyperparathyroidism

There are three main types:

1. Primary: Primary hyperparathyroidism occurs when one or more of the parathyroid glands become enlarged or develop a benign tumor called an adenoma. This causes an overproduction of PTH, which results in increased calcium levels in the blood. Primary hyperparathyroidism is the most common form of the condition and is typically found in people over 50, particularly in postmenopausal women.
2. Secondary: This type develops as a result of another condition that causes low calcium levels in the body, which in turn triggers the parathyroid glands to overproduce PTH. Chronic kidney disease is the most common cause of secondary hyperparathyroidism, as it impairs the kidneys’ ability to regulate calcium and phosphorus levels. Vitamin D deficiency, which leads to lower calcium absorption from the intestines, can also cause secondary hyperparathyroidism.
3. Tertiary: Tertiary hyperparathyroidism occurs when secondary hyperparathyroidism persists for an extended period, even after the underlying cause has been treated. In this case, the parathyroid glands may become permanently overactive, producing excessive PTH even when calcium levels return to normal or increase.

Causes

The causes depend on the type of the condition:

• Primary: The primary cause is the development of a benign adenoma in one of the parathyroid glands, accounting for about 85% of cases. In some cases, more than one gland may be enlarged (hyperplasia), leading to increased PTH production. Rarely, primary hyperparathyroidism can result from parathyroid cancer, but this is extremely uncommon.
• Secondary: The most common causes are conditions that lead to chronic low calcium levels. These include chronic kidney disease (CKD), which results in poor calcium and phosphorus balance, and vitamin D deficiency, which limits calcium absorption in the intestines. Gastrointestinal malabsorption syndromes, such as celiac disease, can also contribute to secondary hyperparathyroidism by reducing calcium absorption.
• Tertiary: This is often a progression of long-standing secondary hyperparathyroidism, particularly in patients with chronic kidney disease. The prolonged overactivity of the parathyroid glands results in their failure to respond appropriately to normal or high calcium levels, leading to autonomous PTH secretion.

Hyperparathyroidism symptoms

The symptoms can vary widely depending on the severity of the condition and the levels of calcium in the blood. Some people with mild hyperparathyroidism may be asymptomatic, while others may experience more pronounced symptoms, including:

1. Bone and Joint Issues:
   • Bone pain and fragility: Excess PTH causes calcium to be removed from the bones and released into the bloodstream, leading to bone loss and an increased risk of fractures.
   • Osteoporosis: A long-term consequence of hyperparathyroidism is the thinning of bones, particularly in the spine, hips, and wrists.
2. Kidney Problems:
   • Kidney stones: Elevated calcium levels can lead to the formation of calcium-based kidney stones.
   • Impaired kidney function: In severe cases, prolonged hypercalcemia can lead to kidney damage or chronic kidney disease.
3. Neurological and Cognitive Symptoms:
   • Fatigue: People with hyperparathyroidism often experience chronic fatigue and weakness.
   • Depression and anxiety: Mood disturbances, including depression, anxiety, and irritability, can occur.
   • Memory loss: Difficulty with concentration and memory can also be a symptom, often referred to as “brain fog.”
4. Gastrointestinal Symptoms:
   • Abdominal pain: Hypercalcemia can lead to digestive issues such as nausea, vomiting, and constipation.
   • Peptic ulcers: Increased calcium levels may stimulate excess acid production in the stomach, increasing the risk of ulcers.
5. Cardiovascular Symptoms:
   • Hypertension: High blood pressure is often associated with hyperparathyroidism.
   • Arrhythmias: Elevated calcium levels can disrupt the normal electrical activity of the heart, leading to abnormal heart rhythms.
6. General Symptoms:
   • Thirst and frequent urination: Hypercalcemia can lead to excessive thirst and increased urination.
   • Muscle weakness: Muscle weakness, particularly in the legs, is common in people with hyperparathyroidism.

Diagnosis

The diagnosis typically involves a combination of blood tests, imaging studies, and sometimes bone density tests. Here are the main steps in diagnosing the condition:

1. Blood Tests:
   • Calcium levels: Elevated calcium levels in the blood (hypercalcemia) are a hallmark of hyperparathyroidism.
   • PTH levels: High levels of parathyroid hormone confirm the diagnosis.
   • Vitamin D levels: These are often measured to rule out secondary causes of hyperparathyroidism, such as vitamin D deficiency.
   • Phosphorus and creatinine levels: These help assess kidney function and phosphorus balance.
2. Bone Density Test (DEXA Scan): A bone density test may be ordered to assess bone strength and detect osteoporosis, particularly in individuals at risk of bone loss due to hyperparathyroidism.
3. Imaging Tests:
   • Ultrasound or Sestamibi Scan: These imaging studies can help identify enlarged parathyroid glands or adenomas.
   • CT or MRI scans: In some cases, more advanced imaging may be necessary to locate abnormal parathyroid tissue.
4. Kidney Function Tests: Since hyperparathyroidism can affect kidney function, kidney function tests may be performed to assess the extent of any kidney damage.

Hyperparathyroidism treatment

The treatment approach depends on the severity of the condition, the underlying cause, and the presence of symptoms. The main treatment options include:

1. Observation and Monitoring: In mild cases, particularly if the patient is asymptomatic, doctors may recommend regular monitoring of calcium and PTH levels without immediate treatment. This is often referred to as “watchful waiting.” Bone density tests and kidney function tests may also be performed periodically to monitor for complications.
2. Surgical Intervention: Surgery to remove one or more overactive parathyroid glands (parathyroidectomy) is the definitive treatment for primary hyperparathyroidism. This is recommended for patients with significant symptoms, elevated calcium levels, osteoporosis, or kidney stones. The surgery is typically highly effective, with most patients experiencing normalization of calcium levels and improvement in symptoms after the procedure.
3. Medications:
   • Calcimimetics: These medications, such as cinacalcet, help reduce PTH production by mimicking the effects of calcium on the parathyroid glands. They are often used in people with secondary hyperparathyroidism due to chronic kidney disease or in those who cannot undergo surgery.
   • Bisphosphonates: These drugs help protect bone density by preventing bone resorption and are sometimes used in patients with osteoporosis due to hyperparathyroidism.
   • Hormone replacement therapy (HRT): Postmenopausal women with primary hyperparathyroidism may benefit from HRT to reduce bone loss, though the risks and benefits of HRT must be carefully considered.
4. Addressing Underlying Causes: In cases of secondary hyperparathyroidism, treating the underlying cause is critical. This may involve managing chronic kidney disease, supplementing with vitamin D, or addressing calcium malabsorption issues. Phosphate binders may be used to manage elevated phosphate levels in people with kidney disease.

Complications of Untreated Hyperparathyroidism

If left untreated, it can lead to several long-term complications, including:

• Osteoporosis and Fractures: Prolonged elevation of PTH can result in significant bone loss, making bones more prone to fractures.
• Kidney Damage: Chronic hypercalcemia can cause kidney stones, impaired kidney function, and even kidney failure in severe cases.
• Cardiovascular Issues: Untreated hyperparathyroidism is associated with an increased risk of high blood pressure, heart disease, and arrhythmias.
• Neurocognitive Decline: Persistent hypercalcemia can lead to cognitive issues, including memory problems and difficulty concentrating.

Living with Hyperparathyroidism: Long-Term Management

For those living with with the disease, long-term management is essential to minimize complications and improve quality of life. Here are some strategies for managing the condition:

1. Regular Monitoring:
   • People with mild hyperparathyroidism who are not undergoing surgery should have their calcium and PTH levels checked regularly to monitor for changes.
   • Bone density tests should be performed periodically to assess for osteoporosis.
   • Kidney function tests may be needed to monitor for kidney stones or other complications.
2. Diet and Lifestyle Modifications:
   • Calcium intake: Contrary to what some may think, people with hyperparathyroidism do not need to avoid calcium altogether. In fact, maintaining a moderate calcium intake (1,000 to 1,200 mg per day) is essential for bone health. However, calcium supplements should be used cautiously and under medical supervision.
   • Hydration: Staying well-hydrated can help prevent kidney stones by diluting calcium in the urine.
   • Vitamin D: Adequate vitamin D levels are important for calcium metabolism, but supplementation should be done carefully and under medical supervision to avoid worsening hypercalcemia.
3. Exercise: Regular weight-bearing exercises, such as walking or resistance training, can help maintain bone density and prevent osteoporosis.
4. Follow-Up with Specialists: People with hyperparathyroidism, especially those with complications like osteoporosis or kidney stones, should work closely with endocrinologists, nephrologists, or other specialists to ensure comprehensive management.

Hyperparathyroidism is a complex condition that can significantly impact various aspects of health, particularly bone and kidney function. Early diagnosis and appropriate management are essential for preventing complications such as osteoporosis, kidney stones, and cardiovascular issues. Whether through surgical intervention, medication, or careful monitoring, most people with hyperparathyroidism can manage their condition effectively and lead healthy lives. Regular follow-up with healthcare providers, lifestyle modifications, and a proactive approach to bone and kidney health are key to living well with hyperparathyroidism.