High parathyroid hormone levels (hyperparathyroidism) cause wide-ranging symptoms common to many disorders. Even though high blood calcium (hypercalcemia) is most commonly the result of overactive parathyroid glands, parathyroid hormone levels are rarely tested. Read on to find out how to prevent hyperparathyroidism or detect it on time.
What is Hyperparathyroidism?
Hyperparathyroidism means having too much parathyroid hormone (PTH) in the blood. The disorder is classified as primary, secondary, or tertiary.
Primary hyperparathyroidism occurs when high PTH levels are caused by abnormal function of the parathyroid gland. Usually, high blood calcium levels also are present.
Secondary hyperparathyroidism occurs when high levels of PTH in the blood are a response to low blood calcium or other mineral levels.
Tertiary hyperparathyroidism can develop when the high levels of PTH that are caused by secondary hyperparathyroidism continue even after the initial cause has been addressed.
How Common Is Primary Hyperparathyroidism
Primary hyperparathyroidism is more than twice as common in women than in men [R].
The chances of developing it becomes greater with age as hyperparathyroidism is more common in postmenopausal than premenopausal women [R].
In one study, the incidence of hyperparathyroidism was highest among black Americans (138 per 100,000), followed by whites (110 per 100,000), Asians (80 per 100,000), and then Hispanics (66 per 100,000) [R].
Causes of Primary Hyperparathyroidism
Parathyroid gland malfunctions are most commonly caused by a benign tumor (adenoma) [R].
The second most common cause is an increase in the size of the parathyroid gland (hyperplasia) [R].
Hyperparathyroidism Symptoms Checker
- Have kidney stones
- Feel that your muscles are weak
- Have bad/slow digestion
- Have high blood pressure
- Frequently experience bone fractures (especially in postmenopausal women)
- Have impaired cognition
- Feel depressed
- Have heart problems
High PTH levels can be detected following these tests:
- PTH level (not a routine test)
- Blood calcium levels [R]
- Bone density measurement [R]
- Medical imaging for kidney stones and vertebral fractures [R].
Consequences of Primary Hyperparathyroidism
High levels of PTH often cause high blood calcium levels (hypercalcemia), which cause many health issues.
Some health issues may result directly from the excess of PTH overstimulating its receptors in various parts of the body (including the kidneys, bones, brain, muscles, heart, and blood vessels). For example, one study found that increased stiffness in heart vessels was associated with high PTH levels but was not associated with calcium levels [R].
Osteoporosis is a major concern for those with primary hyperparathyroidism.
Our bones are constantly undergoing reconstruction; parts are reabsorbed, while new bone tissue is being made.
Bones have specialized cells that perform these actions. Parathyroid hormone controls which cell type is more active, those that build or those that absorb bone [R].
Low levels of PTH with intermittent pulses promote more bone-building activity. Constant and high levels of PTH, which occur with primary hyperparathyroidism, cause more bone to be absorbed and calcium released back into the blood.
Osteoporosis associated with primary hyperparathyroidism may decrease the density in some bones more than others. Bone density measurement of the radius is a better predictor of fracture risk than that of the lumbar spine for patients with hyperparathyroidism [R].
Moreover, high rates of heart disease are associated with osteoporosis, and both are linked to high parathyroid hormone levels [R].
What to Test if You Have Primary Hyperparathyroidism
Monitoring and treating the disorder will most commonly focus on the related kidney and bone problems.
- Blood calcium (ionized or albumin-corrected)
- Blood creatinine
- Urine calcium and creatinine
- Urinary profile to determine kidney stone risk (if calcium in urine is higher than 400 mg/day)
- Blood urea nitrogen (BUN)
- Blood phosphate
- Blood vitamin D
- Imaging to assess bone integrity and strength
- Imaging of the kidneys to detect kidney stones
Possible Treatments for Hyperparathyroidism
Some medications may be effective in the short-term management of hyperparathyroidism. Bisphosphonates, which inhibit bone loss, may improve bone density. Cinacalcet, which inhibits parathyroid gland function, lowers blood calcium levels [R].
Surgical removal of some or all of the parathyroid glands (parathyroidectomy) is currently the only known cure and is used in severe cases of the disorder. Surgery is advised for patients who meet any of the following criteria: age less than 50 years, blood calcium greater than 1 mg/dl, poor kidney function (glomerular filtration rate less than 60 ml/min), or significant reduction in bone density [R].
The most frequent complication from surgery is temporary or permanent hypoparathyroidism (low PTH). About 5% of patients continue to have high levels of PTH after surgery and so require a second surgery [R].
Many measures of quality of life are improved post surgery and complications from the surgery are rare [R].
In secondary hyperparathyroidism, the properly functioning parathyroid glands release more parathyroid hormone in response to low calcium levels.
If treatment of the underlying problem brings calcium back to healthy levels, the parathyroid hormone also should return to normal levels. If the parathyroid hormone level remains high after calcium levels return to normal, that is called tertiary hyperparathyroidism.
Causes of Secondary Hyperparathyroidism
Calcium or Vitamin D Deficiency
Abnormally low levels of calcium in the blood cause high parathyroid hormone levels. Dietary deficiencies in calcium or vitamin D are the most direct causes of low blood calcium levels [R]. Calcium and/or vitamin D supplements along with sun exposure should decrease PTH levels.
Aldosteronism is a disorder in which there is excess production of the hormone aldosterone by the adrenal glands.
The association between aldosteronism and hyperparathyroidism is bidirectional: an increase of one will cause an increase in the other [R].
In patients with aldosteronism caused by an adenoma, removal of the adrenal glands (adrenalectomy) increased calcium levels and brought parathyroid hormone levels back to normal [R].
Chronic Kidney Disease
The kidneys are critical for maintaining normal calcium and phosphorus levels in the blood and for converting vitamin D into its active form. PTH plays a role in those processes, promoting the kidney’s reabsorption of calcium, suppressing reabsorption of phosphorus, and stimulating the activation of vitamin D.
As the kidney loses function, blood calcium and vitamin D levels fall and phosphorus levels increase. These blood conditions signal the parathyroid glands to release more PTH, leading to hyperparathyroidism [R, R].
As kidney disease progress, the incidence of hyperparathyroidism increases: from 40% in stage 3 to 70% in stage 4, and greater than 80% in stage 5 [R].
It can be difficult to know the cause and effect relationship of high PTH levels because other interrelated health disorders often co-occur with chronic kidney diseases, such as malnutrition, diabetes, high blood pressure, anemia, inflammation, and pre-existing heart disease [R, R].
For chronic kidney disease patients, heart-related problems are the primary cause of death and bone disease is a leading cause of disability. PTH imbalances contribute to both conditions [R].
Because parathyroid hormone is involved in both bone and heart disease, measuring its levels is a way to determine the severity of those conditions. Medications and dialysis treatments often are modified based on PTH levels [R].
Vitamin D supplementation in patients on dialysis may lower PTH. Out of 40 research studies of vitamin D therapy for dialysis patients, 29 found PTH levels were lowered [R].
Although some case studies indicate that removal of the parathyroid glands provides health benefits for chronic kidney disease patients with secondary hyperparathyroidism, controlled studies are needed to better determine those benefits [R].
Poor Absorption of Nutrients
Also, rates of secondary hyperparathyroidism increase following gastric bypass surgery [R].
Parathyroid Hormone and Heart Disease
Several studies have investigated whether PTH levels could be used as a proxy for the severity of heart disease when it is not associated with PTH disorders. Results have been inconsistent.
In a study of patients with chronic heart failure, higher PTH levels predicted heart failure. A different study found that the ratio of active vitamin D (calcitriol) to PTH was a better predictor of death in chronic heart failure patients than the level of either one alone. A lower ratio (i.e., lower vitamin D with higher PTH levels) indicated higher risk [R, R].
How Your Genes Could Be Causing Hyperparathyroidism
Familial isolated hyperparathyroidism is diagnosed when there is a family history of hyperparathyroidism but no other known hormonal disorders. Investigations into genetic causes are underway [R].
Multiple endocrine neoplasia types 1 is a rare (~1 in 30,000 people) inherited disorder that causes tumors in the hormonal glands and small intestine. The disorder is caused by mutations in the MEN1 gene, which codes for a protein involved in cell division and growth: menin. Primary hypothyroidism is usually the first sign of the disorder [R, R].
- Hypocalciuric hypercalcemia involving genes CASR, GNA11, or AP2S1
- Neonatal severe primary hyperparathyroidism involving the CASR gene
- Multiple endocrine neoplasia type 2A involving the RET gene
- Multiple endocrine neoplasia types 4 involving the gene CDKN1B
- Hyperparathyroidism-jaw tumor syndrome involving the gene CDC73.
Natural Ways to Prevent Hyperparathyroidism
Increasing physical exercise can lower the risk of developing hyperparathyroidism [R].
2) Weight Loss
Larger waist size in women increases the risk of developing hyperparathyroidism [R].
3) Calcium Supplements
Women who took calcium supplements (at least 500 mg/day) had a 30% lower risk of developing primary hyperparathyroidism than women who took no supplements. Also, women who took the highest amount of calcium supplements (~1800 mg/day) had about half the risk of as those taking the lowest amounts [R].