CALCIUM HOMEOSTASIS & PARATHYROID DISORDERS

1. CALCIUM HOMEOSTASIS & PARATHYROID DISORDERS DR. MAHMUDUL HUQUE HOLY FAMILY RED CRESCENT MEDICAL COLLEGE

3. Calcium Homeostasis • calcium homeostasis is the mechanism by which the body maintains adequate calcium levels. Derangements of this mechanism lead to hypercalcaemia or hypocalcaemia, both of which can have important consequences for health.

4. Normal range: 9–10.5 mg/dL or 2.2–2.6 mmol/L

5. Corrected Ca level • Corrected calcium (mg/dL) = measured total Ca (mg/dL) + 0.8 X (4.0 - serum albumin [g/dL]

6. Hypercalcemia • Polyurea, polydipsia • Renal colic, lethargy • Anorexia, nausea, dyspepsia • Peptic ulcer, depression, drowsiness • Impaired cognition • Acute/chronic onset • Malignant Hypercalcaemia Ca>12 mg/dl

7. Causes of Hypercalcemia Abnormal parathyroid gland function • Primary or tertiary hyperparathyroidism • Lithium induced • familial hypocalciuric hypercalcaemia Malignancy • Lungs, breast, renal, ovarian, colon, Thyroid malignancy. • haematologic malignancy (multiple myeloma, Lymphoproliferative disorders)

8. Contd… Vitamin-D metabolic disorders • hypervitaminosis D (vitamin D intoxication) • elevated 1,25(OH)2D levels (e.g. sarcoidosis) Others • Thyrotoxicosis – TSH, FT3, FT4 • Thiazide use • Paget's disease of the bone • Addison’s disease • severe secondary hyperparathyroidism • milk-alkali syndrome

9. Treatment • Hydrate with Normal saline: 4-6L deficient • Diuretics: Look for K, Mg • Salmon calcitonin: BD, 5-8 u/Kg, 3-4 days • BISPHOSPHONATES: Pamidronate & Zoledronic acid • Plicamycine / Gallium nitrate (toxic) • Steroids: 40mg/day In granulomatous sarcoidosis • Haemodialysis • Treat cause

10. Hypercalcaemia • Oral, perioral and acral paresthesias, tingling or 'pins and needles' sensation. This is often the earliest symptom of hypocalcaemia. • Carpopedal Spasm and generalized tetany • Latent tetany: Trousseau sign of latent tetany (eliciting carpal spasm by inflating the blood pressure cuff and maintaining the cuff pressure above systolic). Chvostek's sign (tapping of the inferior portion of the zygoma will produce facial spasms). • Epilepsy, Psycosis • Papilloedema • Basal ganglia Calcification • Metastatic calcification • Severe Hypocalcaemia <6mg/dl

11. Causes of Hypocalcaemia Absent parathyroid hormone (PTH) • Hereditary hypoparathyroidism • Following parathyroidectomy • Following thyroidectomy, the parathyroid glands are located very close to the thyroid and are easily injured or even accidentally removed during thyroidectomy • In DiGeorge Syndrome, a disease characterized by the failure of the third and fourth pharyngeal pouches to develop, the parathyroid glands do not form and there is thus a lack of PTH. • Storage – Al, Cu, Fe • Trauma or vascular formation

12. Contd…. • Alkalosis: Resp. + Metabolic • CRF • Vit. D deficiency, Malabsoption syndrome • Pseudo hypoparathyroidism • Acute pancreatitis • Drug- Ca lowering drugs • Massive Blood transfusion • Osteoblastic metastasis

13. Treatment of Hypocalcaemia • If alkalosis: Rebreath expired air or 5% CO2 in O2 . • 10% Calcium gluconate slow IV to keep Ca >7mg/dl till relief. • Oral Calcium: 1.5-3 gms elemental Ca, 500 mg of Ca tab. • If serum Ca fall bellow 7mg/dl, give again after 6hrs Ca gluconate Upto 100mg/day. • Tab. 1α in persistant hypo parathyroidism • Magnesium (nalepsin) in calcium resistant persons

14. Hyperparathyroidism

15. Contd…. • Serum biochemical hyper and hypo calcaemia occupies the clinical spectrum of parathyroid disease. So are the features of hyper/hypo calcaemia.

16. Diagnosis • Features of hypercalcaemia • PTH radio-immuno assay • 24 hr urinary calcium increased • Radiology: Osteitis fibrosa cystica, Pepperpot skull, Bone cyst- brown tumour • Tumour localisation by- Surgery, USG, CT, Neck catheterisation, PTH measurement, Technetium isotope imaging.

17. Treatment • Manage hypercalcaemia • Remove the tumour • Tagging the remnant • Transplant in symptomatic, young & progressive Secondary: Calcitriol to suppress PTH Tertiary: Remove

18. Hypoparathyroidism • Hypocalcaemia, signs and symptoms of decreased Ca. • Hyperphosphatemia • Undetectable PTH • Exclude serum Mg deficiency. If (+) Functional Hypoparathyroidism.

19. Hypoparathyroidism • It is due to destruction, • surgery, • Vascular damage, or • idiopathic as part of poly-glandular failure or agenesis (DiGeorge syndrome)

20. Pseudohypoparathyroidism • Pseudohypoparathyroidism is a condition associated primarily with resistance to the parathyroid hormone. Patients have a low serum calcium and high phosphate, but the parathyroid hormone level (PTH) is actually appropriately high (due to the hypocalcaemia). • Increased PTH + biochemically Low Ca and High PO4 + body stigma. • Features: Short stature, obese with round face, short 4th and 5th metacarpal, mental retardation, defective teeth & bone formation

21. Short stature, obese with round face

22. Short 4th and 5th metacarpals blunting of the fourth and fifth knuckles of the hand

23. Pseudopseudohypoparathyroidism • Pseudopseudohypoparathyroidism (pseudoPHP) is an inherited disorder, named for its similarity to pseudohypoparathyroidism in presentation. The term pseudopseudohypoparathyroidism is used to describe a condition where the individual has the phenotypic appearance of pseudohypoparathyroidism, but is biochemically normal. • It is sometimes considered a variant of Albright hereditary osteodystrophy.

24. Young woman with short stature, disproportionate shortening of the limbs, generalized obesity, and round, flattened face. Radiograph of the hand showing the shortened 4th and 5th metacarpals

25. Thank You