Physiologic Interactions Between the Adrenal- and the Parathyroid Glands

Physiologic Interactions Between the Adrenal- and the Parathyroid Glands

To investigate possible physiologic interactions between the adrenal- and the parathyroid glands in patients with secondary hyperparathyroidism.

In primary hyperparathyroidism, chronic-elevated PTH levels seem to stimulate the renin-angiotensin-aldosterone system (RAAS) which may explain the increased risk of cardiovascular disease. In addition to increased PTH levels, vitamin D has been shown to inhibit the RAAS. However, a possible physiologic interaction needs further investigation.

The purpose of the study is to investigate changes in the RAAS in otherwise healthy postmenopausal women with secondary hyperparathyroidism due to vitamin D deficiency when p-PTH is normalized.

Furthermore, we will evaluate whether an angiotensin 2 receptor blocker can lower PTH in patients with secondary hyperparathyroidism.

Inclusion Criteria:

• Secondary hyperparathyroidism due to Vitamin D deficiency

Exclusion Criteria:

• Cardiovascular disease
• Renal failure
• Liver failure
• Treatment with antihypertensive medication or diuretics
• Treatment with lithium, NSAID or glucocorticoids
• Calcium supplement more than 500 mg per day or Vitamin D supplement more than 25 microgram per day
• Medical treatment for osteoporosis
• Systolic blood pressure below 120 mmHg
• Hypercalcaemia (more than 1,33mmol/L)
• Use of solarium or planned trip to countries, that might increase the endogenous vitamin D synthesis
• Allergic reaction to ACEi or ARBs.