Effect of cigarette smoking on bone mineral density in healthy Taiwanese middle-aged men.

The effect of cigarette smoking in relation to bone mineral density (BMD) remains inconclusive, especially in middle-aged men. This cross-sectional study was conducted to examine the effect of smoking on BMD in 837 healthy Taiwanese males (532 never-smokers, 258 current smokers, 47 former smokers; aged 46-64 yr), recruited at their routine health examination. Subjects with suspected conditions affecting bone metabolism or receiving any medications affecting bone metabolism were excluded. BMD of the lumbar spine (LSBMD) and femoral neck (FNBMD) was measured with dual-energy X-ray absorptiometry. After adjustment for confounding variables (age, weight, physical activity, alcohol consumption, and caffeine intake), we found that the mean value of LSBMD was significantly (2.9%) lower in current smoker compared with never-smokers (p=0.024), but no significant difference was observed in FNBMD. No statistically significant association was observed between former smokers and never-smokers in any of the BMD sites, indicating that quitting smoking did have a positive effect on bone density. Compared with never-smokers, current heavy smokers who consumed at least 20 cigarettes/d (n=94) had 3.8% lower LSBMD (p=0.04), but no significant difference was observed in FNBMD. In the correlation analysis, the duration of smoking was negatively associated with LSBMD (r=-0.166, p=0.004), but no association was shown in FNBMD. Our results suggested that both smoking status and duration of smoking were deleterious factors on the bone density of the lumbar spine, and the effect was cumulative with duration and quantity.

Evaluation of urine deoxypyridinoline and bone mineral density in 861 Chinese during routine health examination.

The aim of this study was to investigate the interrelation among urine deoxypyridinoline (DPD), age, sex, and bone mineral density (BMD) and to clarify whether DPD can be used to screen for low bone mass (T-score <-1) of the lumbar spine and proximal femur in the Chinese population. We reviewed medical records over a 1-yr period of all subjects who completed an annual health examination. A total of 302 men (age: 48.20 +/- 10.86 yr) and 559 women (age: 46.45 +/- 11.16 yr) who lived in the Taipei area, had no major systemic disorders, and underwent urine DPD test and BMD examination of both the lumbar spine (L-BMD) and proximal femur (F-BMD) were recruited. The urine DPD was weakly correlated with middle age in men (r = 0.154, p < 0.01). There was no correlation between DPD and age in women. The DPD and L-BMD were weakly correlated in both middle-aged men (r = -0.165, p < 0.05) and women (r = -0.171, p < 0.01), and moderately correlated in elderly women (r = -0.315, p < 0.01). There was a higher correlation between DPD and F-BMD in men than in women, especially in the middle-aged groups (men: r = -0.258, p < 0.01; women: r = -0.170, p < 0.01). Women in the highest tertile of DPD had 2.40 times the risk (95% confidence interval: 1.49-3.85) of those in the lowest tertile after age adjustment. There was poor agreement or none between DPD and BMD measurements in patients with low bone mass at either site in either sex. Urine DPD tests to substitute for BMD measurements in routine health examination for Chinese is not recommended.