Dose-related effect of urinary cotinine levels on bone mineral density among Korean females.
To evaluate the dose-dependent relationship between smoking and bone mineral density (BMD), the present study used the BMD dataset of the Korean National Health and Nutrition Examination Survey IV (KNHANES IV). The linearity of BMD for urinary cotinine levels was demonstrated with statistical significance in postmenopausal females.


BACKGROUND
It is well established that smoking is an important lifestyle risk factor for bone health (bone loss, osteoporosis, and fracture). However, several studies demonstrated conflicting evidence for a dose-dependent relationship between smoking and bone health. To evaluate the dose-dependent relationship between smoking and BMD, the present study estimated dose-related effects of smoking (urinary cotinine level) on BMD at various sites (femur neck, total femur, and lumbar spine) in females with controlling menopausal status.


METHODS
The present study used the BMD dataset of the KNHANES IV, which was performed in 2008 and 2009. A total of 4,260 pre- and postmenopausal females were included in the present study. Dose-response relationships between BMD and urinary cotinine levels were estimated using analysis of covariance in pre-menopausal females and postmenopausal females, respectively.


RESULTS
In postmenopausal females, the regression coefficients for BMD with urinary cotinine levels were -0.006, -0.006, and -0.008 (g/cm2 per ng/ml) at femur neck, total femur, and lumbar spine, respectively (p value<0.05). Thus, the linearity of BMD for urinary cotinine levels was demonstrated with statistical significance in postmenopausal females.


CONCLUSIONS
Our findings suggested a significant dose-related effect of urinary cotinine level with BMD at femur neck, total femur, and lumbar spine among postmenopausal females.
Department of Preventive Medicine, Center for Occupational and Environmental Medicine, College of Medicine, The Catholic University of Korea, 222 Banpo-Daero Seocho-gu, Seoul, 137-701, Republic of Korea.
J-P
JP
Myong
H-R
HR
Kim
S E
SE
Choi
J-W
JW
Koo
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine; D015519:Bone Density / Q000502:physiology*; D003367:Cotinine / Q000652:urine*; D005260:Female; D005269:Femur / Q000503:physiopathology; D005272:Femur Neck / Q000503:physiopathology; D006306:Health Surveys; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology / Q000652:urine; D017697:Premenopause / Q000502:physiology / Q000652:urine; D012907:Smoking / Q000503:physiopathology* / Q000652:urine; D012959:Socioeconomic Factors
D015415:Biomarkers; D003367:Cotinine