Passive smoking: it is associated with an increased risk of osteoporosis and fracture

The risk of osteoporosis and osteoporotic fracture is increased in people exposed to secondhand smoke, according to a U.S. study involving a Japanese population, presented at the congress of the International Osteoporosis Foundation in Toronto.

Bone mineral density decreases

A meta-analysis confirmed that smoking was a risk factor for fracture, but the impact of passive smoking on bone health has not yet been studied, indicate Yu-Hsiang Hsu, Harvard School of Public Health in Boston and colleagues, in the summary of their poster.

The researchers evaluated the impact in 7095 men, 4259 premenopausal women and 2,022 postmenopausal women aged 25-64 years living in rural China. Exposure to passive smoking was defined by the presence of a spouse or other family member smoking daily.

The risk of low bone mineral density (BMD) was increased with passive smoking for men and premenopausal women, but not postmenopausal women.

Thus, compared to non-smokers not exposed to passive smoking, non-smoking premenopausal women saw their risk of osteoporosis multiplied by 2.6 if only one family member smoked daily, and 3.0 times from two smoking family members. Their risk of fracture was 2.6 times when at least two family members were smokers.

The authors report for smokers and people exposed to secondhand smoke, compared to non-smokers exposed to a risk of 1.8 times the risk of osteoporosis and osteopenia multiplied by 1.3.

These results are consistent with the hypothesis of an alteration with passive smoking levels of estrogen hormones key to bone health, says Dr. Hsu said in a statement. He says he plans to conduct a follow-up study to correlate serum levels of cotinine, a nicotine derivative which appears only in the blood of people exposed to cigarette smoke, and hormone levels.

Lower BMD in young men

Another study presented at this conference shows, meanwhile, that active smoking is associated with lower BMD in young men.

This association was demonstrated in the elderly, but the results were controversial among adolescents emphasize Mattias Lorentzon and colleagues at the University of Gothenburg, Sweden, in the summary of their oral communication.

The GOOD study evaluated 1,068 men aged 18 to 20 years. The researchers found that smokers had a lower than non-smokers at the whole body (-2.1%) BMD of the lumbar spine (-4.3%) and femoral neck (-5.3 %).

They also determined, through three-dimensional images obtained, that smoking mainly affected the cortical portion of the bone, by reducing its thickness and thus potentially affect the resistance of the bone.