Effects of PTH Replacement on Bone in Hypoparathyroidism

Study Summary

Hypoparathyroidism is a rare condition associated with a low level of parathyroid hormone (PTH) in the blood. Hypoparathyroidism can be genetic and show up in childhood, or it can occur later in life. If it occurs later, it is usually due to damage or removal of the parathyroid glands during neck surgery. PTH helps control the amount of calcium in blood, kidneys, and bones. Low levels of calcium in the blood can cause a person to feel sick. It can cause cramping or tingling in the hands, feet, or other parts of the body. A very low blood calcium can cause fainting or seizures. The standard treatment for hypoparathyroidism is a form of vitamin D (calcitriol) and calcium supplements. Keeping normal blood levels of calcium can be difficult. Sometimes there is too much calcium in the urine even if the calcium levels in the blood are low. High calcium in the kidneys and urine can cause problems such as calcium deposits in the kidney (nephrocalcinosis) or kidney stones. High levels of calcium in the kidney may keep the kidney from functioning normally. Treatment with PTH will replace the hormone you are missing. Your disease may be better controlled on PTH than on calcium and calcitriol. Researchers at the NIH have conducted prior studies to establish synthetic human parathyroid hormone 1-34 (HPTH) as a treatment for hypoparathyroidism. Other studies have shown that PTH may improve calcium levels in blood and urine. The primary purpose of this research study is to evaluate the effects of synthetic human parathyroid hormone 1-34 (HPTH) replacement therapy on bone in adults and teenagers with hypoparathyroidism. The study takes 5 (Omega) years to complete and requires 12 inpatient visits to the National Institutes of Health Clinical Center in Bethesda, MD. The first visit will help the study team decide whether you are eligible. This visit will last 2 to 3 days. After taking calcium and calcitriol for 1 - 7 months you will return to the NIH Clinical Center for the baseli

Primary Outcome

Participants (in Cohorts 2 and 3) were randomized to receive their second bone biopsy at year 1, 2, or 4 after the start of HPTH therapy. For Cohort 2, the baseline bone biopsy was completed at the start of CC on the original protocol. For Cohort 3, the baseline biopsy was completed immediately prior to the first HPTH dose. Because the sample sizes for the 1-, 2- and 4-year biopsies are reduced due to the early termination of the study, so the 2-, and 4-year biopsies were collapsed into one biop

Interventions

• DRUG PTH 1-34