Metabolic Bone Disease (WIP) Flashcards
What is metabolism?
The chemical processes that occur within a living organism in order to maintain life.
What is catabolism?
“destructive metabolism” - involves the breakdown of complex organic matter leading to the release of energy and waste matter
What is anabolism?
“constructive metabolism” - involves the synthesis or build up of substances such as proteins. Energy is consumed rather than released.
What are the functions of bone?
- Provision of an endoskeleton and structural support to the body
- Protect vital organs in the body
- Provide a place for blood cell production (bone marrow)
- Serve as a reservoir for minerals such as calcium
Why is calcium important?
- To provide the electrical energy for our nervous system
- To provide the electrical energy for our muscular system.
- To provide strength to our skeletal system.
What is metabolic disease?
A disease caused by some defect in the chemical reactions of the cells of the body
May be disruption of normal metabolic processes resulting in too much or too little of a substance within the body
What is osteoporosis?
A reduction in bone mass through the loss of trabeculae, leading to an increased risk of fracture from low trauma. Bone is otherwise normal (normal mineralisation, unlike osteomalacia).
What are the risk factors for osteoporosis?
long-term use of high-doseoralcorticosteroids
other medicalconditions– such as inflammatory conditions, hormone-related conditions, or malabsorption problems
a family history of osteoporosis–particularly history of a hip fracture in a parent
long-term use of certain medications (e.g. steroids) which can affect bone strength or hormone levels
having a lowbody mass index (BMI)
heavy drinking and smoking
hypogonadism(a condition that causes abnormally low testosterone levels)
malabsorption problems, as experienced incoeliac diseaseandCrohn’s disease
long periods of inactivity, such as long-term bed rest
It is well known that loss of oestrogen causes osteoporosis in women
What is hypercalciuria?
A disorder that causes too much calcium to be lost through the urine, which makes the calcium unavailable for building bone. It is more than twice as common in men as in women.
What constitutes a typical osteoporotic fracture?
- Thinning of cortex
- Sacral insufficiency fractures - vertical bands of sclerosis parallel to SIJs
- Cortical disruption
- Multiple compression fractures
What is the treatment for osteoporosis?
- Reactive lifestyle factors
- falls prevention
- hip protectors
- Proactive lifestyle factors
- diet
- exercise
- Calcium and Vitamin D
- Medications
What is osteomalacia?
Abnormal mineralization in trabecular and cortical bone.
- Rickets of adulthood
- Deficiency of, or resistance to, Vitamin D
or Phosphate handling problem - Defective mineralization of bone
- Alkaline Phosphatase raised, Calcium and Vitamin D low or normal
What is rickets?
Abnormal mineralisation of growth plates, concomitant osteomalacia
May cause bone bowing
What causes osteomalacia or rickets?
- Most common cause: Renal osteodystrophy
- Vitamin D deficiency or abnormal metabolism
- Nutritional: ↓ intake, especially during pregnancy
- Malabsorption states (short gut, celiac disease)
- Lack of sunlight exposure
- Chronic renal parenchymal disease
- Liver disease
- Abnormal phosphate metabolism
- Renal tubular acidosis
- Malabsorption
- Coeliac disease
- Intestinal bypass
- Gastrectomy
- Chronic pancreatitis
- Epilepsy: anticonvulsants; phenytoin, phenobarbitones
- Genetic disease
What is hypercalcaemia?
A common endocrine-related disorder of elevated levels of calcium in the blood.
