Abstract
Previous studies have reported that smoking is associated with reduced bone mass in older adults, but no longitudinal studies have addressed the relationship of smoking behavior and compartmental measures of volumetric bone mineral density (vBMD).
This study aimed to explore the cross-sectional and longitudinal relationships of several indicators of cigarette smoking (smoking status, pack-years, age of onset and smoking cessation) with QCT-derived proximal femur bone measures (trabecular vBMD, integral vBMD and the ratio of cortical to total tissue volume (cvol/ivol)) and with subsequent change in these measures over the next five years, in a population-based cohort of 2633 older adults (55.9% women), aged 66–92 years.
In multiple linear regression adjusting for several potential confounders, current smoking was only associated with lower cvol/ivol at baseline, whereas former smoking was associated with lower trabecular vBMD, integral vBMD and cvol/ivol. Analyses of change in bone measures revealed that compared to never-smokers, current smokers had significantly greater loss of trabecular vBMD, integral vBMD and cvol/ivol. Full-adjusted models included sex, age, education, BMI, Creatinine, high-sensitive C-Reactive Protein, coronary artery calcium score, % weight change from age 50, 25OHD, physical activity, diabetes, arthritis, and respiratory diseases. Among former smokers, longer duration since cessation was related to better bone health at baseline, especially for integral vBMD and cvol/ivol. Pack-years was associated with lower cvol/ivol.
In conclusion, smoking has a differential association with bone health assessed with QCT. Results suggest that, current smoking, but not former smoking, at older age may aggravate the rate of bone loss.