Osteoporosis: risk factors, bone density tests and prevention review

Osteoporosis is a bone condition that often goes unnoticed until a bone breaks. This article explains what it is, who is at risk, how it is found and what can be done to protect bones, using information from the NHS, MedlinePlus and the US National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS).

1. Introduction

Osteoporosis weakens bones and makes them more likely to break. The NHS says it develops slowly over several years and is often found only after a fracture, which is the medical word for a broken bone ^[1]. NIAMS and MedlinePlus describe it as a loss of bone mineral density (the amount of mineral packed into bone) or bone mass, or a change in bone structure, that reduces bone strength ^{[2, 3]}. Because it usually causes no symptoms before a break, it is sometimes called a silent disease ^{[2, 3]}.

The bones most often broken are the hip, the bones of the spine (called vertebrae) and the wrist ^{[2, 3]}.

2. Causes and risk factors

Bone is living tissue that is constantly being broken down and replaced. MedlinePlus explains that osteoporosis develops when more bone is lost than is rebuilt, which becomes more likely with age ^[2]. The NHS notes that some bone loss is a normal part of ageing, but in some people it happens much faster ^[1].

The sources list these risk factors ^{[1, 2, 3]}:

• Age and sex. Women lose bone quickly in the years after menopause, and the risk is higher if menopause starts early or the ovaries have been removed. Men can also be affected, particularly in older age ^{[1, 3]}.
• Family history. This includes a parent who had a hip fracture.
• Small or thin frame, or low body weight.
• Low hormone levels, such as low oestrogen or low testosterone.
• Long-term medicines. Examples named include steroid tablets used over a long time, some medicines for epilepsy, some cancer treatments and medicines that reduce stomach acid. Never stop a prescribed medicine without asking your doctor.
• Other health conditions, such as inflammatory joint disease, hormone problems, digestive conditions that limit the absorption of food, and eating disorders.
• Lifestyle. Little regular exercise, smoking, heavy drinking and a diet low in calcium, vitamin D or protein.

3. Signs and symptoms

The NHS says osteoporosis usually has no pain until a bone breaks ^[1]. Wrist, hip and spine fractures are most common, and the arm, pelvis and ribs can also break, sometimes after something as small as a cough or sneeze ^{[1, 3]}. When bones in the spine collapse, they can cause long-term back pain, loss of height and a stooped, forward-bent posture, known as kyphosis ^{[1, 3]}.

The NHS also describes osteopenia, an earlier stage in which bone density is lower than average for age but not low enough to count as osteoporosis. It does not always progress to osteoporosis ^[1].

4. Diagnosis and tests

A doctor looks at your medical history, risk factors and a physical examination, which may include checking height, weight, posture, walking and muscle strength ^[2]. A fracture risk tool may be used to estimate the chance of a break in the next ten years ^{[1, 2]}.

The main test is a bone density scan, often called a DEXA scan. The NHS describes it as a short, painless test, usually lasting 10 to 20 minutes ^[1]. The result is a T-score that compares your bone density with that of a healthy young adult. A score above minus 1 is normal, between minus 1 and minus 2.5 suggests osteopenia, and below minus 2.5 indicates osteoporosis ^[1].

MedlinePlus notes that screening is recommended in the United States for women aged 65 and over, and for younger women after menopause who have extra risk factors, while the evidence for routine screening in men is not yet clear ^[2]. Ask your doctor whether a scan is right for you.

5. Treatment and management

The aim of treatment is to slow or stop bone loss and prevent fractures ^{[1, 2]}. The NHS says the decision depends on your fracture risk, which takes account of age, sex and scan results, and that medicines to strengthen bones can be used ^[1]. MedlinePlus explains that some medicines slow bone loss and others help rebuild bone ^[2]. Your doctor chooses which, if any, are suitable and explains how to take them safely.

Other parts of management include ^{[1, 2]}:

• Eating a balanced diet with enough calcium, vitamin D and protein.
• Regular weight-bearing exercise (activity done on your feet, such as walking), muscle-strengthening and balance exercises.
• Stopping smoking and limiting alcohol.
• Taking steps to prevent falls.
• Avoiding movements that stress the spine, such as twisting or bending forward from the waist, if your doctor advises it ^[2].

After a fracture, the NHS says painkillers, heat and cold treatment and relaxation methods can help recovery ^[1].

6. Prevention and self-care

The sources suggest ^{[1, 2, 3]}:

• Do regular weight-bearing exercise such as walking, and add strength and balance work.
• Eat foods rich in calcium and vitamin D. The NHS lists a daily vitamin D supplement as one way to help keep bones healthy, so ask your doctor or pharmacist whether it suits you ^[1].
• Do not smoke, and limit alcohol.
• Remove hazards at home that could cause a fall, and keep sight and hearing checks up to date ^[1].

7. Special groups

Women have smaller bones and lower peak bone mass than men, and they lose bone more quickly after menopause ^{[1, 3]}. Men are affected too, especially in older age ^[3]. Children and teenagers rarely develop osteoporosis. A rare form called juvenile osteoporosis has an unknown cause, and most children recover without treatment ^[3]. People taking long-term steroid tablets or living with certain conditions are at higher risk, so they should mention it to their doctor ^{[1, 2]}. Pregnancy and breastfeeding raise the body's calcium needs, so ask your doctor about diet ^[3].

8. When to see a doctor

See a doctor if you have risk factors such as an early menopause, a parent with a hip fracture or long-term steroid use, so your fracture risk can be assessed and a scan arranged if needed ^[1]. Get prompt medical help after any fall or knock that may have broken a bone, or if you notice sudden back pain, loss of height or a stooped posture ^{[1, 3]}. Seek care quickly for severe pain, a limb that looks out of place or cannot be used. Tell your doctor about every medicine, supplement and treatment you use.

In an emergency, call your local emergency number (112 in India, 911 in the United States).

9. Conclusion

Osteoporosis weakens bones and is often discovered only after a fracture. Age, menopause, family history, some medicines and conditions, and lifestyle all affect risk. A bone density scan and a fracture risk assessment help doctors plan care, which usually combines food, exercise, fall prevention and, where suitable, medicines. Looking after your bones early, and asking about your own risk, are the most useful steps a reader can take.