Calcium Metabolism Disorders Flashcards
hypercalcaemia aetiology
Primary hyperparathyroidism
Malignancy
Drugs; Fit D, thiazides Granulomatous disease: Sarcoid , TB Familial hypocalciuric hypercalcaemia High turnover: bedridden, thyrotoxic, Paget's Tertiary hyperparathyroidism
Primary hyperparathyroidism
Primary overactivity of parathyroid gland
-e.g. adenoma
High calcium
High PTH
Secondary hyperparathyroidism
Physiological response to low calcium or Vit D
Low calcium
High PTH
Tertiary hyperparathyroidism
Parathyroid becomes autonomous after many years of overactivity
(e.g. renal failure)
High Calcium
High PTH
Hypercalcaemia: Genetic syndromes
MEN1/ MEN2
- Developed a parathyroid adenoma with hypercalcaemia at young age
Familial isolated hyperparathyroidism
hypercalcaemia clinical features
Bones
Stones
Abdominal Groans
Psychic moans
Acute
- Thirst
- Dehydration
- Confusion
- Polyuria
Chronic
- Myopathy
- Fractures
- Osteopenia
- Depression
- hypertension
- pancreatitis
- DU
- renal calculi
Hypercalcaemia Investigation
PTH CT chest, abdo and pelvis Myeloma Screen Urine Calcium Excretion PET Scan
Hypercalcaemia: Further investigations- from PTH Results
Normal/ High PTH
- Urinary calcium excretion
- Increased UrCa: Primary/ Tertiary Hyperparathyroidism
- Decreased UrCa: Familial hypocalciuric hypercalcaemia
Low PTH (high phosphate)
- Bone Pathology
- Increased ALP: Mets, Sarcoidosis, Thyrotoxicosis
- Decreased ALP: Myeloma, Vit D Toxicitiy
Diagnosis of Primary Hyperparathyroidism
Raised serum calcium
Raised serum PTH (or inappropriately normal)
Increased urine calcium excretion
- Ensure Vitamin D replete
Familial Hypocalciuric Hypercalcaemia (FHH)
Familial (autosomal dominant)
- deactivating mutation in the calcium sensing receptor
FHH diagnosis
Mild hypercalcaemia
Reduced urine calcium secretion
PTH (marginally) elevated
Genetic screening
hypercalcaemia of malignancy mechanisms
metastatic bone destruction
PTHrp from solid tumours
Osteoclast activating factors
hypercalcaemia of malignancy diagnosis
Raised calcium phosphate and alkaline phosphatase
X-ray, CT, MRI, PER
Isotope bone scan
Hypercalcaemia; Acute Treatment
Fluids; rehydrate with 0.9% saline 4-6L in 24 hours
Once rehydrated consider loop diuretics (avoid thiazides)
Biphosphonates: single dose will lover Calcium over 2-3 days (maximum effect at 1 week
Steroids occasionally used (for sarcoidosis)
Chemotherapy may reduce calcium in malignant disease (egg, myeloma0
Primary Hyperparathyroidism : Management
Cinacalet
- Calcium mimetic
- Patient require treatment but unsuitable for surgery
- Approved for tertiary hyperparathyroidism and parathyroid carcinoma
Surgery
-not always required