Osteoporosis – B. Pharma 2nd Semester Pathophysiology notes pdf

Osteoporosis

Content

         
Definition of osteoporosis

         
Pathogenesis

         
Diagnosis

         
Therapy

         
Future development

Objective

At the end of the lecture student will be able
to

       Explain osteoporosis

       Define pathogenesis of osteoporosis

       Describe the Factors affecting
osteoporosis

       Briefly explain the treatment of
osteoporosis

Osteoporosis

Definition

         
Clinical

      
Loss of bone mass sufficient to significantly
increase  the risk of fracture

         
Diagnostic

      
T score – number of standard deviations above
or  below the mean for a similar healthy
30 year old

·        
Normal BMD = T: 0 to -1

·        
Osteopenia BMD = T: -1 to -2.5

·        
Osteoporosis BMD = T: less than -2.5

      
Z score – number of standard deviations above
or  below the mean for the patients age,
sex and ethnicity

Epidemiology of Osteoporosis

         
United
States

      
10 million individuals with osteoporosis

      
34 million individuals with osteopenia

         
Fracture
Risks over age 50

      
50% of women will have an osteoporosis
related  fracture

      
25 % of men will have an osteoporosis related
fracture

         
Estimated
costs

      
Direct health care $14 billion each year

Pathogenesis of Osteoporosis

         
Peak bone mass

         
Etiology Bone loss

         
Age

         
Secondary causes

Peak Bone Mass

         
Genetically determined

                      –
    70-75%

      
Driven by sex hormones during puberty

      
Depends on site measured – spine, femur, radius

         
Ethnicity

      
Chinese American later than Caucasians

         
Women

      
Peak accrual ages 11-15

      
95 per cent achieved by late teens

         
Men

      
Peak accrual later teens

      
Maximum spine age 20

      
Radius and femur by mid twenties

Factors Affecting Peak Bone Mass

         
Delay or Failure of puberty

      
Primary Hypogonadism

         
Turners syndrome

         
Klinefelter syndrome

         
Absent cervix, uterus, cervix and/or vagina

         
Cryptorchidism

         
Chemotherapy, Radiotherapy

         
Chronic systemic diseases

      
Secondary Hypogonadism

         
Kallmann syndrome

         
CNS tumors, infiltrative disorders

         
Malnutrition

         
Chronic systemic illness

Etiology of Bone loss in Osteoporosis

Estrogen Deficiency

         
Women

      
Occurs earlier

      
At menopause bone loss rates to increase by 2 to
6 fold

      
For subsequent 6-8 years

      
Impairs calcium absorption from gut

         
Men

      
Testosterone declines age

      
Estrogen declines age

      
Both androgens and estrogen contribute

Fracture Risk with Aging

Secondary Causes of Accelerated
Bone-loss/

Osteoporosis

         
Inherited
disorders

      
Osteogenesis imperfecta tarda

      
Thallasemia

         
Amenorrhea

      
Eating disorders

      
Low weight

      
Excess Exercise

      
Female athlete triad

         
Energy deficiency

         
Low bone mineral density

         
Amenorrhea

      
Premature ovarian failure

         
Respiratory

      
Cystic fibrosis

         
Gastrointestinal

      
Celiac sprue

      
Post Gastric by pass

      
Inflammatory bowel disease

         
Renal

      
Idiopathic hypercalciuria

      
Chronic renal failure

         
Post
organ transplant

      
Immunosuppressive therapy

         
Endocrine

      
Hyperthyroidism

      
Hyperparathyroidism

      
Cushing’s syndrome

      
Hypogonadism

      
Vitamin D deficiency

         
Rheumatology

      
Rheumatoid arthritis

      
Seronegative athropathies

         
Lifestyle

      
Smoking

      
Alcohol

         
Drugs

      
Glucocorticoids

      
Cyclosporine

      
Anti seizure medications

         
Phenobarbital

         
Phenytoin

      
Heparin

      
Chemotherapy

         
Aromatase inhibitors

      
Thyroxine

         
Over replacement

Diagnosis of 

Osteoporosis

         
Approach to patient

         
Investigations

      
Bloods

      
Urine

      
Imaging

      
FRAX use

         
Calcium and Vitamin D

Osteoporosis Investigations

         
Bloods
-Basic

      
CBC

      
Electrolytes and eGFR

      
Serum calcium and phosphate

      
TSH

      
Testosterone (Men)

      
Serum protein electrophoresis

      
Bone markers (consider)

         
Urine

      
24 hour urine

      
Volume

      
Creatinine and calcium

Bone Mineral Density Testing

        
Bone mineral density testing

      
Important means of assessing fracture risk

      
Not stand alone test

         
Other risk factors have impact on fracture risk

      
occasionally more significant impact than bone
density  results alone

      
Glucorticoids

         
All known risk factors should be considered when
deciding  to treat patients

      
Mostly treating patients based on risk

      
No overt disease

         
We need better tools for assessing fracture risk

Summary

         
Osteoporosis is an important public health
problem

         
Accurate diagnosis and treatment requires the
use of bone densitometry.

         
Radiologists play a central role in the
diagnosis and  management

      
of this disease:

      
measuring bone density

      
diagnosing fractures

      
pointing out secondary causes of bone loss


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