Table 3.

Saturation effect analysis of BMI (kg/m²) on total BMD (g/cm²).

Total bone mineral density	Model: saturation effect analysis
BMI turning point (K),kg/m2	21.5
<K, effect 1	0.036 (0.034, 0.037) <0.001
>K, effect 2	0.005 (0.004, 0.006) <0.001
Subgroup analysis stratified by age
BMI turning point for 8–9 years old(K),kg/m2	16.9
<K, effect 1	0.023 (0.019, 0.027) <0.001
>K, effect 2	0.004 (0.003, 0.005) <0.001
BMI turning point for 10–11 years old(K),kg/m2	16.4
<K, effect 1	0.035 (0.027, 0.042) <0.001
>K, effect 2	0.006 (0.005, 0.007) <0.001
BMI turning point for 12–13 years old(K),kg/m2	17.2
<K, effect 1	0.050 (0.038, 0.062) <0.001
>K, effect 2	0.005 (0.004, 0.006) <0.001
BMI turning point for 14–15 years old(K),kg/m2	20.9
<K, effect 1	0.026 (0.021, 0.030) <0.001
>K, effect 2	0.004 (0.002, 0.005) <0.001
BMI turning point for 16–17 years old(K),kg/m2	24.2
<K, effect 1	0.017 (0.014, 0.020) <0.001
>K, effect 2	0.000 (-0.001, 0.002) 0.621
BMI turning point for 18-19 years old(K),kg/m2	22
<K, effect 1	0.021 (0.015, 0.027) <0.001
>K, effect 2	0.001 (0.000, 0.003) 0.028

Age, gender, race, education level, ratio of family income to poverty, activities status, ciabetes status, ALT, ALP, AST, total calcium, total cholesterol, direct HDL cholesterol, LDL cholesterol, triglyceride, phosphorus, blood urea nitrogen, and serum glucose were adjusted.