L15: Hyperparathyroidism & Hypercalcemia Flashcards
Normal serum Ca
8.5 - 10.5 mg
Forms of Calcium In Body
- Ionized Ca
- Non-ionized Ca
Ionized Ca
50 % biologically active form responsible for Ca action.
Non-Ionized Ca
50 % subdivided into:
- Protein bound: (40 %) of no physiological significance
- Ca complexes in bones & teeth: (10 %)
Serum Ca Control is By …..
- Parathormone (PTH)
- Vit D
- Calcitonin
- Acid/Base Balanse
- Glucocorticoides
- T3,T4
- GH
Normal Level of Parathormone (PTH)
(0. 1 - 1 ng /ml)
Net Effect of Parathormone (PTH)
↑ Ca & ↓ Po4
Effevts of Parathormone (PTH)
Vitamin D & Serum Ca
Effects of Vitamin D
Calcitonin & Serum Ca
Where is Calcitonin secreted from?
Para follicular (C-cells) of thyroid gland
effects of Calcitonin
↓ Osteoclastic bone resorption
↑ Renal excretion of Ca & Po4
Acid-Base Balance & ca Serum level
Acidosis → ↑ ionized Ca
Alkalosis → ↓ ionized Ca
Glucocorticoids & Ca Control
↓ Ca & Po4 absorption causing steroid induced osteoporosis.
T3&T4 & Ca Control
↓ Bone mineral density → osteoporosis in hyperthyroidism
Growth Hormones & Serum Ca
Table Showing Effects of PTH, Vit D & Calcitonin on Bone, Kidney & Intestine & Overall effect
Def of Hyperparathyroidism
Hyperparathyroidism means abnormal increase in PTH secretion
Etiology of Hyperparathyroidism
- 1ry hyperparathyroidism
- Familial
- 3ry Hyperparathyroiism
Causes of 1ry Hyperparathyroidism
- Sporadic solitary adenomas 80 to 85%
- Multiple gland hyperplasia 10 to 15 %.
- Parathyroid carcinoma for about 1%
Causes of Familial Hyperparathyroidism
1) Multiple endocrine neoplasia type 1 (parathyroid, pancreas and pituitary)
2) Multiple endocrine neoplasia type 2a (parathyroid, Pheochromocytoma and thyroid medullary carcinoma)
3) Familial hypocalciuric hypercalcemia (FHH).
(Characterized by hypocalciuria, mild PTH elevation and mild hypercalcemia)
3ry Hyperparathyroidism
This occurs following secondary hyperparathyroidism in case of CRF due to prolonged PTH stimulation leading to → development of autonomous adenoma.
CP of Hyperparathyroidism
Most Common Clinical Presentation of Hyperparathyroidism
The most common clinical presentation of primary hyperparathyroidism (PHPT) is asymptomatic hypercalcemia detected by routine biochemical screening.