Metabolic bone disease Flashcards
Vitamin D and bone pathology?
Skin - D3
Liver
Kidney
The primary function of vitamin D is to enable the body to absorb calcium from the intestines, which is then used to mineralize bones.
Stronger bones
Vitamin D and bone remodelling?
- Vitamin D helps regulate calcium and phosphate metabolism
- Vitamin D helps maintain bone homeostasis
- Vitamin D helps regulate the activity of osteoblasts and osteoclasts, which are bone cells that form and break down bone
- Vitamin D helps mineralize bone, which is part of fracture healing
Relationship between parathyroid hormone and vitamin D and bone pathology?
low vitamin D levels trigger increased PTH production, resulting in excessive bone resorption and bone loss; essentially, low vitamin D can indirectly cause bone problems by stimulating too much PTH secretion
Rickets?
sever childhood deficiency of calcium or vitamin D
Both needed for mineralisation of the bone
Deficiency causes demineralisation of the bone
Symptoms of rickets?
Bowing of the legs in childhood
Bone pain
Poor growth
Failure to thrive
Osteomalacia?
a disease that causes bones to soften and weaken. It’s also known as adult rickets.
Osteomalacia symptoms?
Bone pain, especially in the hips
Muscle weakness, especially in the thighs, shoulders, and trunk
Bone fractures
Pins and needles, especially in the hands and feet
A change in the way you walk
Causes of osteomalacia?
A lack of vitamin D, which helps the body absorb calcium
A lack of calcium or phosphate
Digestive or kidney disorders
Genetic defects
Other health conditions
Gene associated with osteogenesis imperfecta?
COLA gene
Types of osteogenesis imperfeceta?
Type I
The most common and mildest type of OI
Symptoms include loose joints, muscle weakness, and a blue or gray tint to the whites of the eyes
People with type I can live a normal lifespan
Type II
The most severe type of OI
Symptoms include death at birth or shortly after, severe bone deformities, and numerous broken bones
Type III
The most severe type among those who survive the neonatal period
Symptoms include easily broken bones, moderate to severe bone deformity, and small stature
Symptoms of OI?
Bones break easily, even with minimal force
Bones may bow or deform, such as bowing of the legs
Bone pain
Barrel-shaped chest
Curved spine
Vertebrae in the spine may collapse or compress
Other symptoms
Blue, purple, or gray tint to the whites of the eyes (sclera)
Face shaped like a triangle
Brittle, misshapen, or discolored teeth
Malocclusion of teeth
Hearing loss
Breathing problems
Loose joints
Weak muscles
Skin that bruises easily
Small stature
Management of OI?
surgical
,medical - bisphosphonates
Social adaptations
Genetic
Pagets disease?
Increased bone resorption followed by increased bone formation
Localised disorganised bone remodelling
Mutataion in pagets?
SQSTMI
causes of largest disease?
Can be underlying genetic mutataion
Activated by an environmental trigger e.g. viral
Symptoms of pagets?
Over 40 with bone pain
Occasionally presents with bone deformity
Excessive heat over the pagets bone
Neurological complication such as nerve deafness
Bowing of the tibia
Most commmon site for Paget’s disease?
Tibia or hip
Tx for Paget’s disease?
Bisphosphonates
The most common treatment, these drugs regulate bone growth and reduce pain. They can be taken orally or injected into a vein.
Calcitonin
A hormone that regulates calcium and phosphate levels, and promotes bone formation. It’s sometimes used when bisphosphonates aren’t an option.
Supportive therapies
Physiotherapy and occupational therapy: Can help with mobility and pain.
Devices: Such as walking sticks or shoe inserts can help with mobility.
Surgery
May be needed to correct problems like fractures, deformities, or severe joint damage. For example, a hip or knee replacement may be necessary.
Osteoporosis?
Metabolic bone disease, dynamic disease
Osteoporosis is a bone disease that causes bones to become fragile and more likely to break. It’s often called a “silent disease” because there may be no symptoms until a bone breaks.
Causes of osteoporosis?
A sedentary lifestyle
Excessive alcohol consumption
Tobacco use
Hormone disorders, such as an overactive thyroid or reduced estrogen and testosterone
Management of osteoporosis?
Changing your diet
Taking supplements, especially calcium and vitamin D
Exercising to improve balance
Taking medications to increase bone density
Preventing falls
Controlling diabetes and high blood pressure
Starting estrogen replacement therapy if you are postmenopausal
Defining osteoporosis fracture?
Low trauma fracture
Femur fracture from standing height
Modifiable risk factors for osteoporosis?
BMI
smoking
Alcohol
Scan for bone density?
DEXA scan
Measure bone density
Endocrine causes of osteoporosis?
Early menopause
Cushings
Hyper and hypoparathyroidism
Hyperthyroid
Medications which cause osteoporosis?
steroids
PPI
Enzyme inducing anti epileptic medications (activating enzymes in the liver)
Aromatase inhibitors ( need to get on bisphosphonates)
GnRH inhibitors
Warfarin (now use DOACs which don’t have the same osteoporosis effects)
Tx for osteoporosis?
Anti resorption therapies
- HRT, testosterone replacement therapy, bisphosphonates, denosumab
Anabolic therapies
- PTH analogues-teriparatide, sclerostin antibody
Side effects of HRT?
increased risk of blood clots
Increased risk of breast cancer
Increased risk of heart disease and stroke if used after large gap from menopause
Negative effects of SERMS?
hot flushes if taken close to menopause
Increased clotting risks
Lack of protection from hip site
Prerequisite for bisonosohates?
Adequate renal function
Adequate calcium and vitamin D status
Good dental health and hygiene advised
- encourage OHI and well fitting denture
Side effects of bisphosphonates?
Nausea, Dyspepsia, Mild gastritis, Abdominal pain, Diarrhea, Indigestion, Bloating, and Wind.
Bone and joint pain
Bone, joint, and/or muscle pain
Swollen joints, hands, or legs
Flu-like symptoms fever, chills, headaches, and muscle and joint aches or pain.
