Table 4

Association of free testosterone with age, ethnicity, BMI, and waist circumference; regression coefficients (β)a from Generalized Estimating Equations

VariableModel 1bModel 2bModel 3b
β (ng/ml)Pβ (ng/ml)Pβ (ng/ml)P
Visit age, per yr−0.0030<0.0001−0.0030<0.0001−0.0029<0.0001
Black race0.00350.180.00490.0680.00330.23
Year 2 BMI, per 1 kg/m2−0.00080.0140.00050.47
Δ BMI, per 1 kg/m2−0.00160.0046−0.0010.19
Year 2 waist circumference, per 1 cm−0.00050.063
Δ Waist circumference, per 1 cm−0.00020.32
  • a Mean change in free testosterone corresponding to the indicated difference in the independent variable.

  • b Each of the models also included terms for secular changes in hormone levels between the Year 2 and 7, and the Years 2 and 10 examinations.