Association between serum estradiol level and appendicular lean mass index in middle-aged postmenopausal women

Table 1 Weighted characteristics of study population based on serum estradiol level quartiles

Serum estradiol level (pg/mL)	Q1 (≤ 3.80)	Q2 (3.88-7.42)	Q3 (7.45-17.50)	Q4 (≥ 17.60)	P value
Age (yr)	54.4 ± 4.1	53.6 ± 4.0	52.9 ± 4.8	49.6 ± 4.9	< 0.001
Race/Ethnicity (%)					0.584
Non-Hispanic White	70.9	68.3	70.1	73.6
Non-Hispanic Black	7.8	14.1	10.9	10.4
Mexican American	6.1	8.3	8.3	6.3
Other race/ethnicity	15.2	9.3	10.7	9.7
Education level (%)					0.520
Less than high school	13.3	14.1	12.7	10.1
High school	24.5	19.2	24.9	19.0
More than high school	62.2	66.6	62.3	71.0
Body mass index (kg/m2)	25.6 ± 4.7	28.8 ± 4.8	32.2 ± 5.9	32.0 ± 8.3	< 0.001
Income to poverty ratio	3.0 ± 1.8	3.3 ± 1.7	3.1 ± 1.5	3.4 ± 1.6	0.143
Moderate activities (%)					0.965
Yes	49.1	47.2	49.7	49.8
No	50.9	52.8	50.3	50.2
Total protein (g/L)	69.9 ± 4.6	70.5 ± 4.1	71.1 ± 4.0	70.0 ± 3.4	0.022
Blood urea nitrogen (mg/dL)	5.0 ± 1.6	4.8 ± 1.6	4.8 ± 1.8	4.6 ± 1.2	0.076
Serum uric acid (umol/L)	263.8 ± 57.0	287.1 ± 69.7	302.9 ± 68.2	286.6 ± 67.6	< 0.001
Serum calcium (mg/dL)	2.4 ± 0.1	2.4 ± 0.1	2.4 ± 0.1	2.3 ± 0.1	0.092
Appendicular lean mass index (kg/m2)	6.1 ± 1.0	6.8 ± 1.0	7.3 ± 1.1	7.5 ± 1.4	< 0.001

mean ± SD for continuous variables: P value was calculated by weighted linear regression model. “%” for categorical variables: P value was calculated by weighted chi-square test.