Table 2.
The association between serum cotinine (ng/mL) and lumbar bone mineral density (mg/cm2).
| Model 1 | Model 2 | Model 3 | |
|---|---|---|---|
| β (95% CI) P value | β (95% CI) P value | β (95% CI) P value | |
| Serum cotinine (mg/dL) | −0.037 (−0.068, −0.005) 0.026 | −0.061 (−0.092, −0.029) <0.001 | −0.046 (−0.078, −0.014) 0.005 |
| Serum cotinine categories | |||
| Q1 | Reference | Reference | Reference |
| Q2 | −7.505 (−19.196, 4.187) 0.204 | −9.279 (−20.975, 2.417) 0.118 | −8.712 (−20.455, 3.019) 0.142 |
| Q3 | −4.270 (−16.707, 8.167) 0.495 | −13.305 (−26.378, −0.232) 0.046 | −13.238 (−26.281, −0.194) 0.047 |
| Q4 | −15.595 (−28.402, −2.787) 0.018 | −26.983 (−40.266, −13.700) <0.001 | −22.771 (−35.842, −9.700) 0.001 |
| Subgroup analysis stratified by sex | |||
| Men | −0.018 (−0.055, 0.020) 0.355 | −0.040 (−0.079, − 0.002) 0.038 | −0.020 (−0.059, 0.018) 0.297 |
| Women | −0.072 (−0.132, −0.012) 0.019 | −0.099 (−0.156, −0.042) <0.001 | −0.089 (−0.146, −0.033) 0.002 |
| Subgroup analysis stratified by race/ethnicity | |||
| Mexican American | 0.045 (−0.106, 0.196) 0.550 | 0.062 (−0.090, 0.214) 0.413 | 0.072 (−0.076, 0.220) 0.331 |
| Non-Hispanic black | −0.018 (−0.084, 0.047) 0.573 | −0.030 (−0.094, 0.034) 0.346 | −0.013 (−0.075, 0.04) 0.667 |
| Non-Hispanic white | −0.084 (−0.124, −0.043) <0.001 | −0.082 (−0.123, −0.041) <0.001 | −0.066 (−0.107, −0.061) 0.002 |
| Other race/ethnicity | 0.047 (−0.027, 0.121) 0.210 | 0.039 (−0.036, 0.115) 0.304 | 0.044 (−0.034, 0.121) 0.265 |
Model 1: no covariates were adjusted. Model 2: age, gender, and race/ethnicity were adjusted. Model 3: age, gender, race/ethnicity, education, body mass index, physical activity, serum albumin, blood urea nitrogen, serum uric acid, serum calcium, and serum phosphorus were adjusted. In the subgroup analysis stratified by sex and race/ethnicity, the model is not adjusted for sex and race/ethnicity, respectively.