谈一谈骨质疏松 (Osteoporosis)

谈一谈骨质疏松 (Osteoporosis)

              Osteoporosis, also means “porous bones,” is a bone disease that affects man and woman, especially women beyond menopause (because estrogen help to protect bone), and can get worse over time.  Osteoporosis leads to fragile bones and increases the risk of a wrist, hip, or spine fracture; People may not realize this is happening in their body because they can’t feel the bones getting weaker unless they have a fracture.  People may not even know they have the disease until they break a bone or a test shows that they have low bone mineral density.  And if people had one broken bone due to osteoporosis, the risk for having another goes up.

                Bone is a dynamic tissue that is constantly undergoing change in a process referred to as bone remodeling. Before osteoporosis, there is a related condition called osteopenia, or low bone mass; Osteopenia occurs when there is a disruption in the bone remodeling process. This disruption is called osteoclastic --- 破骨细胞的 (bone resoption) activity.  The result is a decreased bone mineral density (BMD). BMD determines bone strenth and peaks 30 -- 35 years of age.  About 98% of peak bone mass is achieved by around 20 years of age in most women and 40% - 50% of their bone mass is lost during their life span.  Before and during the peak years, osteoclastic activity is followed by osteoblastic ---- 造骨细胞 (bone deposition or bone-biulding) activity at a constant rate. After the peak years, osteoclastic activity exceeds bone-biulding activity and bone density decreased. So, building strong bone as a young person may be the best defense against Osteoporosis in later adulthood.

                  Osteoporosis is also reported in people who participate in excessive exercise or experience eating disorder, such as anorexia or bulimia; Excessive exercise and eating disorder can cause a low body mass index with resulting amenorrhea and estrogen deficiency in adolescents and young women.

             Bone loss with osteoporosis is a result of both genetic and environmental factors; although no cure for osteoporosis, people can take control by taking precautions and tracking how their osteoporosis is treated to help protect theirself from fractures;

Here are some steps people can take to decrease some risks, and how to strengthen and protect bones:

1.
Osteoporosis risk factors:
 Aging ; 
 Being a woman (postmenopause);  
Family history of osteoporosis or fractures; 
Low body mass index 
Caucasian or Asian; 
Cigarette smoking; 
 Excessive alcohol consumption ; 
Inactive lifestyle (immobilization produces rapid bone loss);
Poor nutrition; 
Low estrogen levels in women ;
 low testosterone levels in men Anorexia;  
Insufficient calcium and vitamin D Use ; 
Certain medications like oral glucocorticoids and some anticonvulsants ;

 
2.
Screening tests: 

A.
The World Health Organization (WHO) has developed a standard for Osteoporosis diagnosis based on BMD values using T-scores;

A T-score is a measurement of how people compare to young adults of the same sex and race. If people fall below average, the T-score will be a negative number. A T-score between -1 and -2.5 indicates low bone mass (osteopenia ), which is mild thinning of bone.  As osteoporosis, a T-score below -2.5 (for example, -3) indicates the bone mass is more than 2.5 times thinner than that of a young adult;



B.
The most widely used bone density test is the DXA test of the hip and lower spine. DXA stands for dual energy X-ray absorptiometry.

C.
According to National Osteoporosis Foundation guidelines, there are several groups of people who should consider bone density testing:

All postmenopausal women below age 65 who have risk factors for osteoporosis.

All women aged 65 and older.

Postmenopausal women with fractures; this is not mandatory because treatment may well be started regardless of bone density.

Women with medical conditions associated with osteoporosis; these diseases number more than 50. A primary care doctor can scan a patient's list of medical illnesses to verify that one of these conditions is not present.

Women whose decision to use medication might be aided by bone density testing.

3. Health intervention: see your doctor;

4. Tips for Preventing Osteoporosis

A.
Diet
· Drink your milk. Low-fat and skim milk, nonfat yogurt, and reduced-fat cheeses are healthy sources of the calcium you need to build strong bones. Fortified milk products also have the vitamin D needed for proper calcium absorption.

· Go fish.

· Fruits and vegetables: Fruits and vegetables are rich in several nutrients that appear to play important roles in bone health, including potassium, magnesium, and vitamin K. Eat a minimum of 5 servings of a variety of different colored fruits or vegetables daily. Teenage and adult women should aim for at least 7 servings, while teenage and adult men should aim for 9 servings (the equivalent of 2 1/2 cups of vegetables and 2 cups of fruit).

· Serve soy. Soy contains not only calcium but also plant estrogens, and it seems to help maintain bone density.

·  Protein deficiency may contribute to the incidence of bone demineralization, although this theory is controversial. about 50% of serum calcium is protein bound, proteinn is deeded for calcium utilization. BUt not too much; because  high protein intake can raise your excretion of calcium. Limit yourself to the RDA of 50 grams daily for women, 63 grams for men.

 B.
Physical activity

Since bone is a dynamic living tissue that gets stronger when stressed and weaker when not used; physically active people generally have higher BMD at all ages than people who are sedentary.

Weight-bearing exercise and strength training are most effective to help keeping  bones strong by causing the muscles and tendons to pull on the bones, which in turn stimulates bone cells to produce more bone to increase or maintain  bone mass. Also, the load on the bones can be created by people's own bodyweight, as in running or jogging, stair climbing, tennis, volleyball, or by external weights like dumbbells or gym machines  in a weight training program.  But, swimming won’t do.....

C.
Supplements

· Calcium: 
Inadequate calcium intake during childhood and adolescence can impair bone development and may prevent the attainment of optimal peak bone mass during early adulthood. In older adults inadequate calcium intake accelerates bone loss and likely contributes to the development of osteoporosis. Although the importance of calcium to bone health is well-recognized, adequate calcium intake alone is not enough to prevent bone loss that could lead to osteoporosis and osteoporotic fracture. An 8-ounce serving of calcium-fortified orange juice or nonfat milk or yogurt provides about 300 mg of calcium. Most calcium supplements, including calcium carbonate, are best absorbed when taken with food, but calcium citrate and calcium citrate malate are also well-absorbed on an empty stomach.

Total daily calcium intake (diet plus supplements) should add up to 1,300 mg for teenagers, 1,000 mg for adults 50 years of age or younger, or 1,200 mg for adults over the age of 50.  Most calcium supplements, including calcium carbonate, are best absorbed when taken with food, but calcium citrate and calcium citrate malate are also well-absorbed on an empty stomach.  Remember, drink a  plenty of water to provent urinary calculus;

· Vitamin D: 
Sun exposure for 5-10 minutes on bare skin, such as the arms and legs, 2-3 times weekly improves vitamin D status with minimal risk of skin damage.
Adults can increase their daily vitamin D intake by taking a supplement that contains 400 IU; older adults and those who avoid sun exposure need to take extra vitamin D for a total of 800 IU/day.

· Fruits and vegetables: 
Fruits and vegetables are rich in several nutrients that appear to play important roles in bone health, including potassium, magnesium, and vitamin K.

Eat a minimum of 5 servings of a variety of different colored fruits or vegetables daily. Teenage and adult women should aim for at least 7 servings, while teenage and adult men should aim for 9 servings (the equivalent of 2 1/2 cups of vegetables and 2 cups of fruit).

D.
Lifestyle changes:

· Quit smoking.

· Avoid excessive alcohol. Too much alcohol prevents the  body from absorbing calcium properly.  Alcohol also has a direct toxic effect on bonr tissue, resulting in decreased bone formation and increased bone absorption.Limit to one drink a day for women and two drinks a day for men.
Excessive caffeine intake can increase calcium loss in the urine.

· Let depression go.  Depression causes the  body to produce cortisol, a stress-related hormone that saps minerals from bones.