Impact of smoking cessation on bone mineral density in postmenopausal women

Background: Although clinical guidelines recommend smoking cessation to improve bone health, the impact of short-term smoking cessation (i.e., 1 year) on bone mineral density (BMD) is not known. We examined the effects of smoking cessation on BMD measurements, markers of bone turnover, and hormone profiles in postmenopausal women. Methods: Postmenopausal women (n=152) who smoked at least 10 cigarettes per day were randomly assigned to behavioral counseling and either nicotine or placebo patch for smoking cessation (3-month treatment with a 1-month taper) and followed for an additional year. The BMD at various sites (hip, spine, wrist, and total body), serum and urine biochemical markers of bone turnover, and sex hormones were measured at baseline and again 1 year after smoking treatment. Women who continuously abstained from smoking between the end of treatment and 1 year later (quitters) (n=42) were compared with women who completed the study and continued to smoke (n=77). Results: Femoral trochanter BMD increased by 2.9% among quitters vs. 0.6% among continued smokers (p=0.02). Total hip BMD increased by 1.52% among quitters vs. 0.43% among continued smokers (p=0.03). Changes in BMD at the femoral neck, radius, spine, and total body did not significantly differ between groups. The effects of smoking cessation on bone were mediated in part by weight gain. Smoking cessation was also associated with an increase in bone alkaline phosphatase. Conclusions: Smoking cessation, relative to continued smoking, increases BMD at the femoral trochanter and total hip in postmenopausal women.