What are the risk factors for osteoporosis?
Unless you break a bone, osteoporosis is painless. It's therefore important to know if you are at risk for developing it. While men and women have many of the same risk factors for osteoporosis and osteopenia, a few are gender-specific. The following factors put you at risk for osteopenia and osteoporosis:
Age. Bone mass decreases as you age. So as you get older, you are more likely to develop osteoporosis. While osteoporosis can affect women and men at any age, it most commonly affects postmenopausal women and older men. The National Osteoporosis Foundation reports that 75% of all cases of osteoporosis are diagnosed in White women over the age of 50. As men age, they too can develop osteoporosis, and it's much more likely to occur in men who are well into late life.
• Gender. Eighty percent of those with osteoporosis are women. Although men account for approximately 20% of cases, they develop osteoporosis much later if they get primary osteoporosis. Men can develop secondary osteoporosis much earlier in life as a result of medications or illness, however. Women are at greater risk because they start with less bone mass and lose it over time at a faster rate than men.
• Race. If you are White, particularly of Northern European descent, or Asian, you are at higher risk for osteoporosis than if you are Hispanic or Black. In fact, 65% of Black women have low bone mineral density. But if you are Black, you are still at significant risk—10% of Black women have osteoporosis. Over 300,000 Black women have osteoporosis, and approximately 90% of the fractures sustained by older Black women are due to osteoporosis. As Black women age, their risk for fracture doubles every 7 years, and the mortality rates following hip fractures are greater among Black than White women. Similarly, older White males are also more likely to get osteoporosis than their Black or Hispanic counterparts.
• Fracture history. If you have broken a bone in adulthood (about 50 years of age or older), you are more likely to have reduced bone mass and therefore osteoporosis. This is particularly important if the fracture occurred with a low amount of trauma or force.
• Family history. If you have a first-degree relative (mother, father, brother, sister, son, daughter) with osteoporosis or osteopenia, you are more at risk for bone loss.
• Poor health. Frailty and dementia are both associated with lower bone mass.
Women are at greater risk because they start with less bone mass and lose it over time at a faster rate than men.
• Cigarette smoking. Nicotine in cigarettes causes problems with bone formation by interfering with the important role of estrogen and testosterone in bone development.
• Excessive alcohol intake. Heavy drinking interferes with calcium absorption as well as the osteoblast activity in bone formation. Ironically, two beers per day for men and two glasses of wine per day for women have been associated with increased bone mineral density. However, more alcohol than this increases your risk of osteoporosis instead of your bone mineral density.
• Excessive caffeine intake. It's not entirely clear exactly how caffeine affects your risk for osteoporosis. One study found that the risk of hip fracture was increased if more than two cups of coffee or four cups of tea were consumed per day. In other studies, coffee and tea consumption was not associated with lower bone density or fracture. In fact, one of these studies found that tea consumption was associated with higher bone density. Conflicting study results aside, moderate caffeine intake (1-2 servings of caffeinated beverages per day) is not likely to affect your bones if you get adequate calcium and vitamin D. The following substances contain the most caffeine:
• Coffee (8 ounces, brewed): about 135 mg (depends on strength and process of brewing)
• Caffeinated tea (8 ounces): about 50 to 70 mg (depends on how long it is steeped)
• Coca-Cola (12 ounces): about 34.5 mg
• Diet Coke (12 ounces): 46.5 mg
You should also be aware that if you are drinking lots of coffee, tea, and soda, you are likely drinking fewer of the calcium-rich beverages such as milk and orange juice.
• Excessive soda intake. While phosphorus is needed for normal bone development, too much of it can cause bone loss. More than 3000 to 4000 milligrams (mg) of phosphorus per day puts you at increased risk. It was once thought that soda (pop, tonic, carbonated beverages other than water) contained excessive amounts of phosphoric acid; however, a caffeinated cola drink contains only about 50 mg of phosphorus. The more important issue is that you may be drinking soda in place of calcium-rich beverages.
• Menstrual history. An increased risk of osteoporosis is associated with delayed puberty in males or females, and amenorrhea in females (lack of menstrual periods for 3 months or more), whether related to an eating disorder, excessive exercise, or other causes. Women who are currently pregnant or breastfeeding usually have some transient bone loss, but this is reversed after the pregnancy and/or after breastfeeding is discontinued. Interestingly, women with more than 10 pregnancies appear to have the same risk of developing osteoporosis as women who have never been pregnant.
• Menopause. Menopause is the most significant factor when it comes to being at risk for osteoporosis. The loss of estrogen at menopause is the most common reason why women get osteoporosis. This drop in estrogen causes bone to be lost rapidly. Only 5% of postmenopausal women have osteoporosis from a source other than loss of estrogen.
• Body weight and body mass index (BMI). Slender, small-boned women are at greater risk than overweight, large-boned women. BMI is a calculation that takes into account both weight and height; there are ranges established to identify underweight (< 18), normal weight (18-25), overweight (> 25), and obese (> 30). If your BMI is low (< 22), your risk for osteoporosis is increased, even though a BMI between 18 and 25 is considered normal. A BMI of 26-28 provides some protection, and a BMI of > 28 increases risk because of the association with reduced activity. If you are > 5' 4" tall and weigh 127 pounds or less, or if your BMI is < 22, you are more at risk for osteoporosis. You can calculate your BMI by taking your weight (in pounds), dividing it by your height (in inches) squared, and then multiplying this number by 704.5. If you don't want to do the math, you can have it calculated for you by visiting the Internet (obesity.org).
• Poor nutrition. Inadequate intake of calcium, vitamin D, citric acid, and phosphorus (or excessive intake of phosphorus) can cause weak bones with decreased bone mass. If you have a diet deficient in calcium, phosphorus, and Vitamin D, you are at increased risk of developing osteoporosis. A diet high in salt or excessively high in protein or fiber can also adversely affect bone because salt increases the excretion of calcium and excessive fiber, or protein can interfere with calcium consumption or absorption. Having a strict vegetarian diet (no foods that are animal-based) is associated with osteoporosis for two reasons: strict vegetarians avoid dairy products, an important source of calcium and vitamin D; and they also tend to have a lower BMI (around 20), which is also linked to osteoporosis.
• Medications. Some medications cause either an increase in bone loss or a decrease in bone formation. The following medications are some that increase your risk of osteoporosis: anticonvulsants, thyroid hormone, corticosteroids, lithium, methotrexate, gonadotropin-releasing hormone (GnRH), cholesteramine, heparin, warfarin, and antacids containing aluminum (see Question 15).
• Medical conditions. There are certain conditions that are associated with an increased risk of osteoporosis either because they interfere directly with bone development or indirectly due to medications required to treat them (see Question 16).
• Sedentary lifestyle. If you do not exercise, even if you have no other risk factors, you may still develop osteoporosis. Bones need the stress of exercise to keep bone formation equal to bone loss (see Questions 42-43).
• Genetic factors. Variations in or absence of a gene that regulates a specific protein receptor that is key to bone development may put you at risk for osteoporosis, sometimes a severe form of it. Several other genes controlling enzymes involved in bone development can affect your risk for osteoporosis exercise.
Few studies have comprehensively evaluated specific risk factors for osteoporosis and osteoporosis-related fractures in men. The National Institutes of Health (NIH) is supporting the "Mr. O" Study of 5700 men who are 65 years of age and older to clarify the most important risks for men.