Smoking After Menopause Linked to Fracture Risk
NEW YORK (Reuters Health) - Cigarette smoking, especially after menopause, increases a woman's risk of breaking a hip, study findings suggest. But researchers also report that drinking alcohol may decrease the risk of fracture.
Women who smoke are often considered to have a higher risk of hip fracture and reduced bone mass than nonsmokers, but the evidence for the link is mixed, according to a team of researchers led by Dr. John A. Baron, of Dartmouth Medical School in Hanover, New Hampshire.
And although moderate drinkers have been shown to have greater bone density than nondrinkers, whether moderate drinking reduces the risk of fracture is uncertain, the authors note in the April 9th issue of the Archives of Internal Medicine (news - web sites).
In the study, Baron's team compared 1,328 postmenopausal Swedish women who had broken a hip with a group of similarly aged women who had not had a fracture. Each of the women filled out a questionnaire that asked about lifestyle and health.
The risk of hip fracture was about 35% higher in current smokers than in women who had never smoked, the investigators found. Former smokers had a 15% increased risk. The results took into account women's use of hormone replacement therapy and obesity.
The number of cigarettes a woman smoked was not strongly related to the risk of fracture, but the number of years spent smoking did increase the risk, the report indicates. For every 5 years smoked, the risk increased 6%.
Smoking after menopause increased the risk of fracture more than smoking before menopause, according to Baron and colleagues. Women who smoked for 11 years after menopause had the same fracture risk as those who had smoked for 24 years before menopause.
The report does provide some good news for women who have been able to kick the habit. Once women quit smoking, the risk of fracture continued to decline the longer they were able to stay tobacco-free. For every 5 years off cigarettes, the fracture risk dropped 2%, and after 15 years off cigarettes, there was no association with hip fracture.
``Cigarette smoking--especially late in life--is harmful to women with regard to postmenopausal hip fracture,'' the authors conclude.
``In contrast, moderate alcohol intake does not appear to increase the incidence of hip fracture and may modestly decrease it,'' they write. The researchers found that women who reported consuming alcoholic beverages were about 20% less likely to have a hip fracture than nondrinkers.
Baron and his colleagues did not investigate possible explanations for the apparent benefits of drinking and risks of smoking. They speculate that smoking may reduce the production of the hormone estrogen. Another possibility, according to the report, is that smoking reduces levels of other hormones and vitamins that could result in weaker bones.
As for alcohol, the research team points out that some studies have shown that alcohol may increase bone density in postmenopausal women.