Osteoporosis

             Osteoporosis is the most common metabolic bone disease and is responsible

             for significant morbidity in elderly women and men. Age dependent bone loss is

             further amplified by menopause due to loss of endogenous estrogen production.

             Fractures are the clinical complication of osteoporosis. The goal is to prevent

             the first fracture. Biochemical tests which estimate bone turnover may aid in
             assessment of osteoporosis and in evaluating response to treatment .

 In the great majority of patients, there are no significant abnormalities

 of Calcium (Total & Ionized), Phosphate or Alkaline Phosphatase

 (Total + Bone isoforms).

 Laboratory tests which estimate bone turnover:

  
  wUrinary pyridinium cross-links (DPD)

             Is the most sensitive and specific marker for bone resorption.

             It is used for early detection and prevention of postmenopausal bone loss.

             After six months of therapy DPD returns to the premenopausal level.

  wOsteocalcin

             Is a very sensitive and specific marker for bone formation.

             It is used to monitor osteoporotic therapy, whereby blood Osteocalcin level drops

             three months after starting therapy.

  wCa ++(urine, serum), PTH, Hydroxyproline

Laboratory tests according to  aetiology:

       1- Idiopathic

       2- Immobilization

       3- Endocrine abnormality

              A- Postmenopausal estrogen def.:        wFSH, LH, E2

              B- Testosterone deficiency:                  wFSH, LH, Testosterone

              C- Cushing's syndrome:                       wCortisol (a.m. & p.m.),
                                                                          Dexamethazone suppression test

              D- Thyrotoxicosis:                               wFree T3, Free T4, TSH,

              E- Primary hyperparathyroidism:           wPTH, Ca (Total & ionized), Phoshorus

              F-  Diabetes mellitus:                          wBlood Glucose (fasting & post prandial),

                                                                         Glycosylated Hb, fructosamine

              G- Growth hormone deficiency:             wGrowth hormone stimulation test

       4- Genetic:                                                            

              A-Osteogenesis imperfecta                   wCa (Total & ionized), Phoshorus, ALP

              B-Homocystinuria                                 wAminogram

       5- Juvenile osteoporosis:                           wVit. D assay

       6- Chronic hypophosphatemia:                  wCa (urine, serum), PTH, Hydroxyproline

       7- Renal hypercalcuria:                             wCa (Urine, serum ),PTH

       8- Nutritional deficiency

             A- Calcium deficiency                            wCa (Total & ionized), Phoshorus

             B- Vitamin C deficiency                         wVit. C assay

             C- Protein deficiency                             wTotal protein, Albumin, A/G ratio

       9- Rheumatoid arthritis                             wRheumatoid factor (Latex,

               Rose Waaler), ANA, DNA

      10- Chronic liver disease                           wLiver function tests

      11-Hematologic malignancy                      wCBC,BoneMarrow,Protein electrophoresis

              A- Multiple myeloma

              B- Leukemia 

              C- Lymphoma 

              D- Myelofibrois   

              E- Myelosclerosis