Modifiable Risk Factors

Most modifiable risk factors, which arise primarily because of unhealthy diet or lifestyle choices, directly impact bone biology and result in a decrease in bone mineral density (BMD). Some modifiable risk factors also increase the risk of fracture independently of their effect on bone itself.

The good news is everyone can take steps to reduce these risk factors for osteoporosis and related fractures.

Modifiable risk factors include:

Alcohol

People with excessive alcohol consumption (>2 units daily) have a 40% increased risk of sustaining any osteoporotic fracture, compared to people with moderate or no alcohol intake. High intakes of alcohol cause secondary osteoporosis due to direct adverse effects on bone-forming cells, on the hormone that regulates calcium metabolism and poor nutritional status (calcium, protein and vitamin D deficiency)1.

Smoking

People with a past history of cigarette smoking and people who smoke are at increased risk of any fracture, compared to non-smokers2.

Low Body Mass Index

Leanness (body mass index (BMI) <20 kg/m2) regardless of age, sex and weight loss, is associated with greater bone loss and increased risk of fracture. People with a BMI of 20kg/m2 have a two-fold increased risk of fracture compared to people with a BMI of 25 kg/m2

Poor nutrition

When insufficient calcium is absorbed from dietary sources, the body produces more parathyroid hormone, which boosts bone remodeling, mobilizing osteoclasts in the bone to break down and sacrifice bone calcium to supply the nerves and muscles with the mineral they need. There are indications that protein is also important in that it may act synergistically with vitamin D and calcium.

Vitamin D deficiency

Vitamin D is also essential, since it helps calcium absorption from the intestines into the blood. Vitamin D is made in our skin with exposure to the sun’s ultraviolet rays. In most people casual exposure to the sun for as little as 10-to-15 minutes a day is usually sufficient. However in elderly people, people who do not go outdoors, and during the winter months in northern latitudes, food or supplemental sources of vitamin D is of importance. At least 800 international units of vitamin D and 1,000 to 1,200 mg of calcium daily can protect against osteoporosis3.

Eating disorders

Osteoporosis can also be compounded by eating disorders such as anorexia nervosa and bulimia.

Oestrogen deficiency

Oestrogen deficiency in women afflicted by these disorders speeds up bone loss in a similar way to that which occurs in post-menopausal women, but to make matters worse, these diseases reduce the robust build up of bone mineral density that usually occurs in adolescence and early adulthood. This may be related to both hormone imbalance and nutritional factors.

Insufficient exercise

People with a more sedentary lifestyle are more likely to have a hip fracture than those who are more active. For example, women who sit for more than nine hours a day are 50% more likely to have a hip fracture than those who sit for less than six hours a day. Read more about the role of exercise in bone health.

Frequent falls

Visual impairments, loss of balance, neuromuscular dysfunction, dementia, immobilization, and use of sleeping pills which are quite common conditions in elderly persons, significantly increase the risk of falling and accordingly increase the risk of fracture. Ninety percent of hip fractures result from falls4.

References

1. Kanis JA, Johnell O, Odén A, Johansson H, De Laet C, Eisman JA, Fujiwara S, Kroger H, McCloskey, Mellstrom D, Melton LJ III, Pols H, Reeve J, Silman A, Tenehouse A. Smoking and fracture risk: a meta-analysis. Osteoporosis Int. 2005;16:155-62
2. Kanis JA. Johansso H, Johnell O, Odén A, De Laet C, Eisman J, Pols H, Tenenhouse A. Alcohol intake as a risk factor for fracture. Osteoporosis Int 2005;16:737-42
3. Dawson-Hughes B, Heaney RP, Holick MF, et al. (2005) Estimates of optimal vitamin D status. Osteoporos Int 16:713-716
4. Woolf AD, Akesson K. Preventing fractures in elderly people. BMJ 2003;327:89-95