biochemical changes in bones disorders

1. Biochemical tests for diagnosis of bone diseases
Serum
•Calcium (2 -2.6 mmol/l)
•corrected calcium
•Albumin (35-50 g/l )
•serum alkaline phosphatase (30 -120 IU/l)
•Phosphate (0.8-1.5 mmol/l)
•parathyroid hormone ( 10 to 55 pg/mL. )
•25-hydroxy vitamin D
Serum 25-OHD concentrations between 50-75 nmol/L are considered healthy
but optimal vitamin D status is when serum concentrations of 25-OHD are 75
nmol/L (30 micrograms/L) or more.
Urine
•Calcium
•Phosphate
•urinary markers, including hydroxyproline, deoxypyridinoline, C-
telopeptide, and N -telopeptide
Correct total Ca( mg/dL) =total Ca ( mg/dL) + 0.8( 4-alb[g/dL[ (

3. 1.Arthritis
2.Osteoporosis
3.Rickets and osteomalacia
4.Paget’s disease

4. Arthritis is not a single disease; it is an
informal way of referring to joint pain or
joint disease. There are more than 100
different types of arthritis and related
conditions.
TYPES OF ARTHRITISTYPES OF ARTHRITIS
• Degenerative Arthritis (Osteoarthritis)
• Inflammatory Arthritis (rheumatoid )
• Infectious (Septic) Arthritis
• Metabolic (Gouty) Arthritis
symptoms
Common arthritis
joint symptoms include
swelling, pain, stiffness
and decreased range of
motion.
Symptoms may be mild,
moderate or severe

6. Osteoporosis is a bone disease that occurs
when the body loses too much bone, makes
too little bone, or both. Osteoporosis
means “porous bone”. Osteoporotic bones
have lost density or mass and contain
abnormal tissue structure. As bones
become less dense, they weaken and are
more likely to break

7. Postmenopausal osteoporosis occurs
in 5% to 20% of women, with a peak
incidence in the 60s.The incidence in
women is eight times higher than
that in men.
Estrogen deficiency is thought to
underlie this form of osteoporosis,
rendering the skeleton more sensitive
to parathyroid hormone (PTH),
resulting in increased calcium
resorption from bone. This in turn
decreases PTH secretion, 1,25-
dihydroxyvitamin D production, and
calcium absorption and ultimately
causes loss of trabecular bone,
leading to vertebral crush fractures
and Colles' fractures.
Senile osteoporosis occurs in
women or men more than 70
years of age and usually is
associated with decreased bone
formation along with decreased
ability of the kidney to produce
1,25(OH)2D3. The vitamin D
deficiency results in decreased
calcium absorption, which
increases the PTH level and
therefore bone resorption. In
type 2 osteoporosis, cortical and
trabecular bone is lost, primarily
leading to increased risk of hip,
long bone, and vertebral
fractures.

8. Treatment of symptomatic osteoporosis has had limited success.
Prevention is preferable to treatment, since no therapy fully
restores lost bone mass.
•PHARMACOLOGIC TREATMENT:PHARMACOLOGIC TREATMENT:
•Hormonal Replacement Therapy
(HRT)  such as Estrogen
•Non-hormonal Replacement Therapy
(NHRT)  such as biphosphonates
(alendronate), calcitonin, selective
estrogen-receptor modulators
(raloxifene), and fluoride
•Others ( testosterone, human
parathyroid hormone &
analougs(Teriparatide), and growth
hormone)
(NON-PHARMACOLOGIC(NON-PHARMACOLOGIC
PREVENTION)PREVENTION)
• The combination of calcium (1.2
g/day) with vitamin D3 (800 IU/day)
• Exercise regularly
• Prevent falls
• Avoid smoking & excessive alcohol
• Maintain an appropriate body
weight

9. This type of osteoporosis is associated with a variety of
conditions, including:
Hormonal imbalances (eg, cushing's syndrome);
Cancer (notably multiple myeloma);
Gastrointestinal disorders (especially IBD causing
malabsorption);
Drug use (eg, corticosteroids, cancer chemotherapy,
anticonvulsants, heparin, barbiturates, valporic acid,
gonadotropin-releasing hormone excessive use of aluminum-
containing antacids);
Pathological conditions: chronic renal failure;
hyperthyroidism; hypogonadism in men;
immobilization,rheumatoid arthritis); and
Poor nutrition (including malnutrition due to eating
disorders).

10. Osteomalacia is a disorder marked by inadequate or defective
mineralization of the skeleton, resulting in soft or fragile bones.
When the disease occurs in children before the
growth plates have closed, it is known as rickets and
tends to produce obvious skeletal deformities.
It typically occurs either when there are insufficient
amounts of vitamin D in the diet or, when the body is unable
to properly absorb and metabolize vitamin D, which is
essential for the absorption of the calcium needed to
maintain strong, healthy bones. It can also occur with calcium
and phosphorus deficiency plus other genetics disorders
Vitamin D deficiency is most often caused
•insufficient exposure to sunlight and nutritional deficiency
•Gastrointestinal malabsorption
•Liver and kidney disease * drugs

11. Hypocalcaemic seizures or tetany,
particularly in the neonatal period.
From the age of 6 months, children
often present with bony deformities of
the chest, pelvis and skull, delayed
dentition, and bone pain.
Children may be irritable and manifest
impaired growth of all body organs.
Increased susceptibility to infections
and respiratory symptoms.
Severe vitamin D deficiency can result
in cardiomyopathy and potentially fatal
heart failure.
Widespread bone pain and
tenderness (especially low back
pain and in the hips), proximal
muscle weakness & lethargy are
the main features of vitamin D
deficiency in adults.
Skeletal deformity
The patient may experience signs
of hypocalcaemia & multiple
fractures which are bilateral and
symmetrical
Low bone density on dual-energy
X-ray
rickets osteomalacia

12. • BIOCHEMICAL FINDINGS
 Blood biochemistry: renal function, electrolytes (including serum
calcium and phosphate), LFTs, parathyroid hormone level:
 More than 80% of adults with osteomalacia have a high concentration
of serum alkaline phosphatase.
 Hypocalcaemia (NV:9-11mg/dl), hypomagnesaemia and
hypophosphataemia (NV: 5-7mg/dl) may be present, depending on
the severity and chronicity of the disease and the patient's dietary
calcium intake.
 Secondary hyperparathyroidism is typical in hypocalcemic rickets.
 Full Blood Count: Anaemia suggests possible malabsorption.
 Urine microscopy to help determine whether the patient has underlying
chronic kidney disease.
 Vitamin D status is most reliably determined by assay of serum 25-
hydroxyvitamin D (25-OHD):
 Vitamin D deficiency: individuals with symptomatic osteomalacia or
rickets have serum 25-OHD of less than 25 nmol/L (10
micrograms/L)

13. TREATMENT
General management
Education: dietary advice (refer to a dietician).
Encourage exposure to sunlight.
Vitamin D supplementation.
Calcium supplementation.
Treatment of any underlying condition.
Treatment of pain.
Orthopaedic intervention may be required.
Children
Oral calciferol in the form of either
ergocalciferol or colecalciferol is the
treatment of choice for children with
rickets (6000 IU(
Calcium supplementation is advisable
during the first weeks of therapy.
Adult
Calciferol in a daily dose of 10000 IU

14. CAUSES
The cause of Paget disease is unknown.
Both genetic and environmental factors
have been implicated.
SYMPTOMS
•Most people who have Paget's disease
of bone have no symptoms. When
symptoms occur, the most common
complaint is
• bone pain.
•Joint pain
Nerve problems:

15. • PATHOGENESIS
 Three phases of Paget disease have been described: lytic, mixed
lytic&blastic, and sclerotic.
 Paget disease begins with the lytic phase, in which normal bone is
resorbed by osteoclasts that are more numerous and larger than normal
osteoclasts. Bone turnover rates increase to as much as 20 times
normal.
 The second phase, the mixed phase, is characterized by rapid
increases in bone formation from numerous osteoblasts. Although
increased in number, the osteoblasts remain morphologically normal.
The newly made bone is abnormal, however, with collagen fibers
deposited in a haphazard fashion rather than linearly, as with normal
bone formation.
 In the final phase of Paget disease, the sclerotic phase, bone
formation dominates and the bone that is formed has a disorganized
pattern (woven bone) and is weaker than normal adult bone. This woven
bone pattern allows the bone marrow to be infiltrated by excessive
fibrous connective tissue and blood vessels, leading to a hypervascular
bone state.

16. • BIOCHEMICAL DIAGNOSIS
 Measurement of serum alkaline phosphatase—in some cases, bone-
specific alkaline phosphatase (BSAP)—can be useful in the diagnosis of
Paget disease.
 Elevated levels of urinary markers, including hydroxyproline,
deoxypyridinoline, C-telopeptide,
and N -telopeptide, may help identify
patients with Paget disease.
 Procollagen I N -terminal peptide (PINP) has emerged as a sensitive
serum marker for bone formation.
 Hypercalcemia or hypercalciuria may develop with immobilization or
coincident primary hyperparathyroidism.
 Hyperuricemia from Paget disease is more common in men than women
and appears to be caused by the increased turnover of nucleic acids
from high bone turnover.
 Serum total acid phosphatase is an osteoclastic enzyme that may be
elevated in active Paget disease.