2. Osteoporosis By Dr. Khattab Omar Prof. & Head of Obstetrics and Gynaecology Department Faculty of Medicine, Al-Azhar University, Damietta

3. Physiology: Bone mineral density (BMD) of the lumbar vertebrae is more than double that of the femur neck & distal radius. Trabecular bones are more sensitive to the loss of estrog Skeletal maturity in females peaks at the age of 30-35.

4. Definitions: WHO T-score for decreased bone density is the number of SD relative to peak bone mass of healthy women aged 30. Osteopenia: T = 1-2.5 SD <young normal mean. Osteoporosis: T >2.5 SD 2.5 SD <young normal mean or -1 to -2.5 SD associated with fracture.

5. Osteoporotic bone is not calcium-deficient. Fracture threshold is reached at around the age of 58. Median age of fracture hip in females is 80. 1 SD decrease in femoral neck bone density increases the risk of hip fracture by 2.6-x.

6. Prevalence: Osteoporosis is very highly prevalent in the industrialized countries mainly due to the high life expectancy. Black Africans develop a higher peak bone mass. The high incidence of lactose intolerance in the Chinese and Japanese may increase their risk of osteoporosis. The increase in postmenopausal osteoporosis (±30%) is attributed partly to improvements in diagnostic methods & partly to increased awareness of the disease. However, only 20-30% of the patients are diagnosed and treated. Prevalence is 6% in men of the same age group (≥1:5). Male : female hip fracture in the elderly is 1:3. This may be due to the lower life expectancy, the higher peak bone mass & the absence of an equivalent to menopause in men. By age 75, nearly half of women have suffered vertebral fractures.

7. Pathophysiology: Osteoporosis occurs after a long latent period due to loss of the honey-comb micro-architecture of bone which is responsible for shock absorption.

8. Aetiology: -Early cases of 2ry amenorr.  failure to achieve optimal peak bone mass or may → progressive bone loss. PCOS, dose not cause bone loss (hyperestrogenism). -Sports maintain or increase bone substance. However, hormonal changes (amenorr. & estrogen deficiency) induced by high competition sports dominate. Also, BMD decreases again very rapidly after the training is stopped. The same for ballet dancers. - Miscellaneous: low body wt, family history, sedentary life-style, thyrotoxicosis, anticonvulsant therapy, long term use of corticosteroids & heparin & COAD. Smoking reduces production of estrogen, blocks estrogen receptors & facilitates conversion of E 2 to E 1

9. -Excessive coffee drinking is a risk factor 2ry to diuresis. -Cola drinks contain high phosphate content. -Alcohol is diuretic; intake is associated with malnutrition smoking, little activity, reduced absorption of vit D & Ca due to cirrhosis & direct inhibition of osteoblasts. - DM is a moderate risk factor. Intermittent acidosis may lead to Ca mobilization. Development of nephropathy leads to renal bone disease (for prevention & ttt: the most important measure is to lower serum P by intake of Ca carbonate).

10. Clinical features -Asymptomatic. -Chronic back pain due to changes in stature. This pain is not an osseous but mainly a soft tissue &/or articular pain. -Pain at other skeletal sites only occurs together with fracture. Acute pain of thoracic vertebral fracture should be differentiated from myocardial infarction. - Low trauma fracture. - Vertebral fractures lead to loss of height, progressive deformity of the trunk, limitation of independence, depression and social isolation.

12. Investigations Bone density studies detect already-existing osteoporosis. Up to now no sufficiently sensitive test. BMD measurement is the most relevant and rather low-priced screening method. 1- Osteoporosis is suspected with increased radiolucency of vertebrae on X-ray films (occurs late after loss of 30-40% of BMD). 2- Densitometry monitor response to therapy.

15. 3- Single photon absorptiometry (densitometry) at the calcaneous and midshaft & distal radius. 3- Single photon absorptiometry (densitometry) at the calcaneous and midshaft & distal radius. 4- Dual photon absorptiometry (densitometry) at L2, 3, 4 and femoral neck. 5- Dual energy x-ray absorptiometry (DEXA; Dual energy computed tomography) measures vertebral body. This is the best means of monitoring bone mass (detects a loss or gain of as little as 1%). Normal bone density at the lumbar spine in patients with fractures at the thoracic spine may be an indicator for non-osteoporotic fractures. 6- Markers of bone turnover: Not routine. Markers have broad reference ranges. One marker of bone formation and one of resorption is sufficient. With recent fracture both formation and resorption occur and both types of markers are elevated. Measurement of markers may be indicated in cases resistant to therapy.

16. Risks Hip, spine and wrist fracture  Has a 20% chance of dying. The most common cause of death is thromboembolism, then pneumonia. Has a 20% chance of dying. The most common cause of death is thromboembolism, then pneumonia. 50% lose independence. 50% lose independence. Every year there is 60 000 hip fracture, 50 000 forearm fracture, 50 000 forearm fracture, 40 000 diagnosed vertebral fracture 40 000 diagnosed vertebral fracture

17. Treatment 1- Increase calcium intake. The normal diet contains 500 mg; women on ERT need extra 500 mg taken at night, while women not receiving oestrogen need extra-1000 mg. 2- Weight-bearing exercise.

18. Treatment 3- Etidronate disodium (Didronel, 1st generation bisphosphonate) is much more effective at improving lumbosacral spine density than hip. Dose: 400 mg OD x 14 followed by Ca carbon. 0.5-1g daily for 76 days (3 month cycle) for >6 months. Other bisphosphonates (allendronate, fosamax) is the most potent bisphosphonate. Dose: 5-20 mg/day for 3 y. The patient should keep upright after intake. 4- HRT is the treatment of choice. Taken for at least 10 years. Norethisterone (progestogen) has a direct effect on bone density. ERT reduces the incidence of osteoporosis by ≥ 50%. There is an 8% increase in bone density in the spine & 4%  in the hip after only 1 y.

19. 5- Calcitonin-human 0.5 mg SQ twice/w. 6- Flouride (Fl) increases bone mass. Flouride is monitored by alkaline phosphatase after 1-2 months. 7- Tibolone(Livial)maintains bone density

20. Thank you