Table 4.

Age-specific association between obesity and depressive symptoms

Variables	No. of cases	Model 1	Model 2	Model 3
		OR (95% CI)	OR (95% CI)	OR (95% CI)
BMI (kg/m2)
18–44 years old
Underweight	53	1.48 (0.80–2.74)	1.48 (0.80–2.74)	1.47 (0.78–2.74)
Normal weight	733	Reference	Reference	Reference
Overweight	773	1.09 (0.83–1.44)	1.09 (0.83–1.44)	1.10 (0.83–1.46)
General obesity	446	1.23 (0.88–1.71)	1.23 (0.88–1.71)	1.24 (0.87–1.76)
P for trend		0.465	0.481	0.468
45–59 years old
Underweight	49	1.81 (1.06–3.09)	1.77 (1.03–3.01)	1.76 (1.03–3.03)
Normal weight	1733	Reference	Reference	Reference
Overweight	1837	0.88 (0.74–1.05)	0.87 (0.73–1.03)	0.85 (0.72–1.02)
General obesity	810	0.86 (0.69–1.07)	0.85 (0.68–1.06)	0.81 (0.64–1.01)
P for trend		0.032	0.022	0.010
60–79 years old
Underweight	240	1.32 (0.94–1.86)	1.33 (0.94–1.87)	1.26 (0.89–1.79)
Normal weight	2873	Reference	Reference	Reference
Overweight	2030	0.84 (0.71–0.98)	0.80 (0.68–0.94)	0.81 (0.68–0.95)
General obesity	619	0.83 (0.67–1.04)	0.76 (0.61–0.94)	0.75 (0.60–0.94)
P for trend		0.004	< 0.001	0.001
P for interaction		0.047	0.006	0.021
WC (cm)#
18–44 years old
Normal WC	1218	Reference	Reference	Reference
Abdominal obesity	787	0.94 (0.74–1.21)	0.94 (0.74–1.21)	0.96 (0.74–1.25)
45–59 years old
Normal WC	2685	Reference	Reference	Reference
Abdominal obesity	1744	0.96(0.82–1.11)	0.86 (0.73–1.01)	0.84 (0.71–0.99)
60–79 years old
Normal WC	4134	Reference	Reference	Reference
Abdominal obesity	1628	0.93 (0.81–1.08)	0.76 (0.65–0.89)	0.77 (0.65–0.90)
P for interaction		0.238	0.035	0.087

Abbreviation: BMI body mass index; WC waist circumference

Model 1: unadjusted;

Model 2: adjusted for age and gender;

Model 3: adjusted for age, gender, educational level, marital status, average monthly income, physical activity, current smoking, current drinking and chronic disease (including coronary heart disease, stroke, hypertension, diabetes and dyslipidemia)

^# Abdominal obesity was classified as WC ≥ 80 cm for women and WC ≥ 90 cm for men