Table 4 Sex-specific mixed effects estimates on waist circumference of study population, coefficient (95% CI)

 Age

0.77(0.57, 0.96)

< 0.001

 Age²

−0.006(− 0.008, − 0.004)

< 0.001

 Phase III

9.49 (7.88, 11.10)

< 0.001

 Phase V

10.44(7.39, 13.49)

< 0.001

 Phase III*age

−0.06(−0.10, − 0.03)

< 0.001

 Phase V*age

−0.06(− 0.12, − 0.001)

0.045

Smoking (Ref: non-smoker)

−1.12(−1.63, − 0.61)

< 0.001

Physical activity (Ref: high)

0.77(0.48,1.07)

< 0.001

Education (Ref: > 12 year)

−0.33(− 0.95, 0.29)

0.295

Spouse: (Ref: married)

−3.11(−3.83,-2.40)

< 0.001

 Age

1.32(1.14, 1.50)

< 0.001

 Age²

−0.010(− 0.013,-0.008)

< 0.001

 Phase III

−4.87(−6.57, −3.17)

< 0.001

 Phase V

−2.84(−5.90, 0.23)

0.070

 Phase III*age

0.13(0.09, 0.16)

< 0.001

 Phase V*age

0.13(0.07, 0.19)

< 0.001

Smoking (Ref: non-smoker)

−0.76(−2.12, 0.60)

0.274

Physical activity (Ref: high)

0.80(0.46, 1.15)

< 0.001

Education (Ref: > 12 year)

2.63(1.83, 3.42)

< 0.001

Spouse: (Ref: married)

−5.25(−6.26,-4.24)

< 0.001