Osteoporosis – B. Pharma 2nd Semester Pathophysiology notes pdf




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




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


     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


        Secondary causes

Peak Bone Mass

        Genetically determined

–    70-75%

     Driven by sex hormones during puberty

     Depends on site measured – spine, femur, radius


     Chinese American later than Caucasians


     Peak accrual ages 11-15

     95 per cent achieved by late teens


     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


        Chemotherapy, Radiotherapy

        Chronic systemic diseases

     Secondary Hypogonadism

        Kallmann syndrome

        CNS tumors, infiltrative disorders


        Chronic systemic illness

Etiology of Bone loss in Osteoporosis

Etiology of Bone loss in Osteoporosis

Estrogen Deficiency


     Occurs earlier

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

     For subsequent 6-8 years

     Impairs calcium absorption from gut


     Testosterone declines age

     Estrogen declines age

     Both androgens and estrogen contribute

Fracture Risk with Aging

Fracture Risk with Aging

Secondary Causes of Accelerated Bone-loss/Osteoporosis

        Inherited disorders

     Osteogenesis imperfecta tarda



     Eating disorders

     Low weight

     Excess Exercise

     Female athlete triad

        Energy deficiency

        Low bone mineral density


     Premature ovarian failure


     Cystic fibrosis


     Celiac sprue

     Post Gastric by pass

     Inflammatory bowel disease


     Idiopathic hypercalciuria

     Chronic renal failure

        Post organ transplant

     Immunosuppressive therapy




     Cushing’s syndrome


     Vitamin D deficiency


      Rheumatoid arthritis

     Seronegative athropathies







     Anti seizure medications





        Aromatase inhibitors


        Over replacement

Diagnosis of Osteoporosis

         Approach to patient





     FRAX use

        Calcium and Vitamin D

Osteoporosis Investigations



     Electrolytes and eGFR

     Serum calcium and phosphate


     Testosterone (Men)

     Serum protein electrophoresis

     Bone markers (consider)


     24 hour urine


     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


        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


        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


1. Can men get osteoporosis?

Yes, men can develop osteoporosis, although it is more common in women.

2. How is osteoporosis diagnosed?

Osteoporosis is diagnosed through bone density tests, with Dual-Energy X-ray Absorptiometry (DXA) being one of the most commonly used methods.

3. What are the most common medications for treating osteoporosis?

Common medications for osteoporosis include bisphosphonates, hormone therapy, and denosumab.

4. Are there natural remedies for preventing osteoporosis?

A balanced diet, regular exercise, and lifestyle changes can help prevent osteoporosis.

5. What is the best age to start focusing on bone health?

It’s never too early to start focusing on bone health, but the earlier, the better. Building strong bones during childhood and adolescence can reduce the risk of osteoporosis later in life.

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