The correlation between serum total alkaline phosphatase and bone mineral density in young adults

Table 3 Stratified analysis of the correlation between serum total ALP and lumbar BMD

	Model 1 β (95% CI) P value	Model 2 β (95% CI) P value	Model 3 β (95% CI) P value
Subgroup analysis stratified by age
20 to 29 years	-0.0013(-0.0016, -0.0010) < 0.000001	-0.0012(-0.0015, -0.0009) < 0.000001	-0.0010(-0.0013, -0.0007) < 0.000001
30 to 40 years	-0.0008(-0.0011, -0.0006) < 0.000001	-0.0006(-0.0008, -0.0004) < 0.000001	-0.0005(-0.0008, -0.0003) 0.000006
Subgroup analysis stratified by sex
Male	-0.0008(-0.0011, -0.0005) < 0.000001	-0.0007(-0.0009, -0.0004) < 0.000001	-0.0006(-0.0008, -0.0003) 0.000015
Female	-0.0012(-0.0014, -0.0009) < 0.000001	-0.0011(-0.0013, -0.0008) < 0.000001	-0.0010(-0.0012, -0.0007) < 0.000001
Subgroup analysis stratified by race/ethnicity
Non-Hispanic white	-0.0006(-0.0009, -0.0003) 0.000031	-0.0005(-0.0008, -0.0003) 0.000140	-0.0004(-0.0007, -0.0002) 0.002834
Non-Hispanic black	-0.0009(-0.0013, -0.0004) 0.000187	-0.0010(-0.0014, -0.0005) 0.000059	-0.0007(-0.0012, -0.0003) 0.002721
Mexican American	-0.0012(-0.0015, -0.0008) < 0.000001	-0.0011(-0.0015, -0.0007) < 0.000001	-0.0010(-0.0014, -0.0006) < 0.000001
Other race/ethnicity	-0.0013(-0.0017, -0.0010) < 0.000001	-0.0013(-0.0016, -0.0009) < 0.000001	-0.0013(-0.0017, -0.0010) < 0.000001

Model 1, no covariates were adjusted
Model 2, age, sex, race/ethnicity were adjusted
Model 3, age, sex, race/ethnicity, education, income to poverty ratio, waist circumference, smoking behavior, alcohol consumption, blood urea nitrogen, serum uric acid, total protein, total cholesterol, serum phosphorus, serum calcium and calcium supplementation were adjusted. In the subgroup analysis stratified by age, sex and race/ethnicity, the model was not adjusted for age, sex or race/ethnicity