Osteoporosis

All you need to know about weak bones (osteoporosis) and prevention of fractures

Normal bone is composed of approximately two-third parts mineral (calcium and phosphorus) and one-third part organic matrix/osteoid (mainly collagen protein). Osteoporosis is a disease of old age which weaken bones due to decrease in both the bone matrix as well as the bone mineral content

Risk factors for osteoporosis:

Old age, Thin built ,Female sex, Early menopause or late menarche, Prolonged amenorrhea  > 1year ,Oophorectomy(removal of ovaries)during reproductive years, Treatment with osteoporosis causing drugs like steroids, Smoking, Alcohol and high caffeine consumption, sedentary life style.

Females are particularly prone for developing osteoporosis after menopause due to lack of hormone production from ovaries. Due to rapid bone loss after menopause vertebral fractures and wrist fractures are common in females. Another type of osteoporosis is senile osteoporosis which occurs due to bone loss in old age. This increases the risk of hip and vertebral fractures in both men and women over the age of 70 years.

Sign and symptoms:

Although most of the patients are, earliest complaint is back pain. A fall in house is the most common cause of fracture in weakened bone due to osteoporosis. Decrease in bone mass causes reduction in strength of bones, thereby leading to pathological fractures. Wrist fractures and vertebral fractures (fractures of back bone) are most common osteoporotic fractures. Hip fractures are also common fractures in elderly person due to simple fall at home.

INVESTIGATIONS

Serum calcium, phosphorus, alkaline (ALK) phosphatase and vitamin D levels are usually normal. X-rays: At least 30% of the bone mass must be lost for osteoporosis to be apparent on the radiographs.

DEXA (dual energy X ray absorptiometry) is commonly done to know the bone marrow density to grade the osteoporosis. Based on the values of DEXA osteoporosis is graded as:

1. Osteopenia: -1 to -2.5 SD
2. Osteoporosis: less than -2.5  without history of fracture
3. Severe osteoporosis: less than -2.5 with history of fracture

Who need a DEXA scan? :

Not all elderly men and all postmenopausal women need DEXA. You need a DEXA scan if:

• You are a postmenopausal woman and have a family history of hip fractures
• You sustained a fracture after a minor fall (both men and women)
• You have had your ovaries removed at an early age
• You had an early menopause (before 45 years)
• You (men or women) are a known case of rheumatoid arthritis which is associated with low bone marrow density
• You are on drugs which reduce bone marrow density, like steroids

Prevention of osteoporosis:

1. Regular weight bearing and resistance exercises are the best way to boost the bone strength. Weight bearing exercises are those exercises in which feet are in contact with the ground or a base like running, jogging, cycling, jumping, etc. Resistance exercises are those exercises in which you lift some weight or exercises against some resistance. Most of the gym exercises like leg curls, leg extension are done against some weight and the muscle pulling action on the bones during the exercises increases the strength of the bones. Regular aerobic and resistance exercise 30 minutes a day and five days a week are recommended to stay fit and healthy.
2. Well balanced diet: Calcium rich diet includes milk and dairy products, leafy vegetables, dry fruits. Pure vegetarian may have deficient vitamin D levels as vitamin D is present only in meat, fish and egg yolks and fortified foods. Adequate Vitamin D is necessary for calcium absorption so if you are pure vegetarian you may need vitamin D  and calcium supplementation along with a healthy diet to prevent vitamin D deficiency.

Treatment of osteoporosis:

Commonly used drugs are:

1. Calcium along with vitamin D: These are very commonly prescribed for management of osteoporosis and also during fracture treatment. Adequate calcium and vitamin D level are necessary for optimal bone health.
2. Bisphosphonates: These are the drugs of choice for both senile and postmenopausal osteoporosis. These are given as weekly or monthly doses. Now injections are available which are given once a year. Tab. These are safe drug but long term therapy (more than 5 years) may cause atypical fractures of thigh bone.
3. Calcitonin: Calcitonin reduces the risk of vertebral fractures only, with no effect on peripheral fractures. Usually given as a nasal preparation and dose for nasal route is 200 IU/day.
4. Recombinant Parathormone (Teriparatide): It should be given only for severe osteoporosis (BMD below -3 or below -2.5 with a fracture) Parathyroid hormone is given as daily subcutaneous injections (20 µg/ day).