Secondary hyperparathyroidism in uremic patients

Parathyroid gland (Parathyroid glands) is located in the back of the neck of thyroid, the side of the trachea, a total of four, about the two respectively. Parathyroid hormone (PTH), a Parathyroid hormone, is used to help the body maintain the balance of calcium and phosphorus in the body

As the calcium ion in the blood fall, parathyroid gland increased thyroid hormone secretion vice, vice thyroxine from three aspects of calcium in the blood normal level:

One, the kidney reduces excretion calcium

Stimulating the kidney to synthesize vitamin D to increase the absorption of calcium in the small intestine

Three, make bone increase release calcium

The cause of the hyperthyroidism of hypothyroidism:

Urine poisoned patients for renal insufficiency, results in the decrease of blood calcium concentration in the body, elevated blood phosphorus, and the lack of active vitamin D3, which stimulate the secretion of parathyroid gland manufacture and parathyroid glands have balance of calcium phosphate in the body. Gradually deteriorated, but associated with chronic kidney disease (CKD) in patients with elevated blood phosphorus concentration, lower blood calcium concentration and activity of vitamin D3 things will more and more serious, lack of such a situation will make the parathyroid gland body constantly stimulated to produce and vice thyroid hormone secretion, will lead to final time onset of hyperthyroidism.

Secondary hyperthyroidism

Secondary sexual vice hyperthyroidism won't have any symptoms, but the stability of continuous deterioration will lead to a variety of body system abnormalities, including bone lesions, pain, muscle weakness, tendon rupture. Soft tissue and calcification of blood vessels; Skin scratching, festering, and central nervous disorder. In the end, the patient's bone loss, bone loss, aching bones, and even rupture, fracture, and the ability to support the skeleton.

Treatment of hyperthyroidism and medication

At present, the treatment of secondary hypothyroidism in China can be pided into:

Phosphorus binding agent

Surgical removal

Treatment of active vitamin D

Treatment of calcium supplements

The phosphorus binding agent is pided into:

Calcium phosphorus binding agent:

Calcium carbonate and calcium acetate are the most commonly used phosphorus combinations. The combination of calcium acetate and calcium carbonate; Calcium lactate and calcium citrate are less able to remove phosphorus. When oral calcium phosphate binds, about 20 percent of calcium is absorbed by the gut, which leads to hypercalcemia. Studies have shown a clear correlation between calcium salt and calcification in soft tissue

Aluminum phosphorus binding agent:

Aluminium hydroxide and aluminum carbonate used to be a widely used combination of phosphorous, better than calcium acetate and calcium carbonate. But the long-term use of aluminium phosphates can cause aluminum to be deposited in bone and nervous system, potentially dangerous for aluminum poisoning. Therefore, containing aluminum phosphate binder is deprecated, now for other method can not only control hyperphosphatemia or adverse reactions of patients, and treatment should be short, such as aluminum hydroxide (2-3 g/d), the course of 4 weeks, no more than 12 weeks. In addition, children dialysis patients can be susceptible to aluminum poisoning and should be banned from using aluminium phosphor.

Non-calcium non-aluminium phosphorus binding agent:

Non-calcium non-aluminium phosphorus binding agent overcomes the shortcoming of the phosphorus binding agent with calcium or aluminum. "Sevelamer hydochloride (p, Renagel

R), the ability to swallow whole, combined with the ability of phosphorus to be comparable to calcium carbonate, reduces the incidence of hypercalcemia. In addition, phosphorus can also reduce the total cholesterol and LDL cholesterol in the blood, but it is expensive.

"Lanthanum carbonate (Fosrenal R, fox lino) phosphate binder, must bite take, less absorbed by the organization, toxicity is small, the effect is good, price is very expensive, but take less, can improve the medication compliance.

Accessory thyroid surgery:

Surgical resection to general anesthesia, in addition to a higher risk, there is also a deputy low thyroid hormone problems after the surgery, the patient vice thyroid element will not be able to reply back to normal concentration range, come down for a long time can lead to poor patient bone growth and increased cardiovascular risk, organ calcification

Treatment of vitamin D:

Patients with nephropathy are often reduced or deficient in the active vitamin D3 synthesis due to kidney failure. Vitamin D can be directly and indirectly used in the sub-thyroid to inhibit PTH synthesis. Studies have shown that vitamin D treatment lowers PTH, improves kidney bone disease and increases bone density, but the mortality rate of patients with kidney disease does not necessarily improve. Major adverse effect of vitamin D treatment to increase the risk of high blood calcium and blood phosphorus and the calcium-phosphorus product rise may increase the risk of vascular calcification, especially at the same time take calcium tablet. In addition, overinhibiting PTH may lead to non-dynamic bone disease. In addition to the active vitamin D, there are two complementary approaches to the active vitamin D, one is oral dosage form and the other is injection dosage form.

Oral dosage forms of active vitamin D:

It takes a long time to reach the effective blood concentration after the absorption of the gastrointestinal tract. In addition, because the side effects of oral dosage forms are more likely to have high blood calcium, so under the condition of severe illness, usually don't use a larger doses to get enough blood levels to inhibit the excessive secretion of thyroid hormone vice. Oral dosage forms of active vitamin D3 also often fail because of our neglect, leading to unstable disease control.

Injections of active vitamin D:

Is mainly used in hemodialysis patients dialysis, because it is injected into the blood, so can quickly achieve higher blood levels than oral dosage forms the curative effect of active vitamin D stronger, faster, and its use is mainly through the medical personnel to give injections, thus can avoid patients forget to take medicine.

Calcium (the latest generation of drugs used to treat hyperthyroidism)

Traditional way treat pair of hyperthyroidism, the use of phosphate binder, active vitamin D (oral and injectable) to reduce the patient's I - PTH value, but the two drugs and blood calcium and phosphorus, the rise of the blood and had to stop using drugs, but also because of drug withdrawal cause vice hyperthyroidism are deteriorating. Is the latest generation of quasi calcium supplements by turn new drugs to treat hyperthyroidism, mainly on the parathyroid gland can affect calcium sensitive receptors, let sensitive receptor increased sensitivity to blood calcium, calcium makes blood calcium in low concentration can inhibit the I - PTH, also borrow by inhibition of iPTH cases, reduce the blood calcium and blood concentration of phosphorus and the calcium-phosphorus product value and the probability of fracture, etc. But it remains to be seen whether patients with kidney disease can improve their mortality. At present, it is commonly used as cinacalcet (the Taiwanese commodity name RegparaR, the American commodity name SensiparR, Europe is MimparaR).

According to the OPTIMA Study pointed out that under the traditional way to treat pair of hyperthyroidism with cinacalcet can reduce I - blood PTH, blood calcium, phosphorus and the calcium-phosphorus product, and can reduce the dosage of the VitD, also found in the baseline I - PTH values between 300 ~ 500 pg/ml of patients, the treatment effect (KDOQI Suggestions I - PTH control range in 150 ~ 300 pg/ml), than the baseline I - PTH values between 500 ~ 800 pg/ml of patients to the good, and use the dosage is low. Although currently in Taiwan is a part of kidney dialysis patients taking cinacalcet effect is good, but I still need to collect further use of cinacalcet patients the clinical trial data for statistical analysis, to further confirm the timing of the clinical use and utility.