CORTEXT Biochemistry week 1 Flashcards
What is Osteoporosis?
Quantitative defect of bone characterised by reduced bone density and increased porosity
What does osteoporosis lead to?
Increased fragility of bone
Increased fracture risk
What happens to bone mineral density as age increases?
Decreases over time past age of 30
Females lose more after menopause
What are the two types of osteoporosis and when do they occur?
Type 1 - Post menopause
Type 2 - Old age
How is osteoporosis diagnosed?
DEXA bone scan
What are the treatments for osteoporosis?
Can’t build up bone density
Can stop further deterioration
Exercise, good diet and sunlight can maintain peak bone density
What is osteomalacia?
Qualitative defect of bone with abnormal softening of the bone due to the deficient mineralization of osteoid secondary to inadequate amounts of calcium and phosphorus
AKA rickets
What are the principle causes of osteomalacia?
Insufficient calcium absorption from the intestine Phosphate deficiency Malnutrition Malabsorption Lack of sunlight exposure CKD
What are the symptoms of osteomalacia?
Bone pain Soft bone deformities Pathological fractures Hypocalcaemia Psuedofractures
What is the treatment for osteomalacia?
Vitamin D therapy
Calcium and phosphate supplementation
What is Hyperparathyroidism/
Overactivity of parathyroid glands with high levels of PTH
What is primary Hyperparathyroidism due to?
Benign adenoma
Hyperplasia
Malignant neoplasia
What does overproduction of PTH result in?
Hypercalcaemia Fatigue Depression Bone pain Myalgia Nausea Thirst Polyuria Renal stones Osteoporosis
What is secondary Hyperparathyroidism?
A Physiological overproduction of PTH secondary to hypocalcaemia caused by lack of vitamin D or CKD
When is tertiary Hyperparathyroidism seen?
Patients with chronic scondary Hyperparathyroidism (usually CKD) who develop an adenoma which will continure to produce PTH despite biochemical correction
What can Hyperparathyroidism result in?
Fragility fractures
Lytic lesions in bone
What is the treatment of Hyperparathyroidism?
Removal of adenomatous gland
Treatment of underlying cause
High serum calcium levels need emergency treatment
-Iv fluids, bisphosphonates, calcitonin
What is renal dystrophy?
Typical bone changes due to CKD
What are the typical bone changes as a result of CKD?
Reduced phosphate exretion Inactive activation of vitamin D resulting in secondary Hyperparathyroidism Osteomalacia Sclerosis of bone Calcification of soft tissues
What is Paget’s disease?
Chronic disorder
Thickened, brittle and mis-shapen bones
What may cause paget’s disease?
Viral infections
Genetic defects
What is the pathogenesis of paget’s disease?
Increased osteoclast activity results in increased bone turnover
Osteoblasts become more active to try and correct bone resorption
The osteoblasts form new bone but this fails to remodel sufficiently and the new bone is thick but brittle and easily fractures
What are the commonly affected bones in paget’s?
Pelvis Femur Skull Tibia Ear
What are the symptoms of pagets?
Can be asymptomatic Arthritis Pathological fractures Deformity Pain Cardiac failure
What is the treatment for paget’s disease/
Bisphosphonates
Calcitonic
Joint replacement
Stabilization
