Overweight in mediating the association between depression and new-onset diabetes: A population-based research from Health and Retirement Study

Table 1 The baseline health status of the population and the inter-group distribution of new-onset diabetes during 1998-2016

Characteristic	All respondents, unweighted No. (weighted %)	Weighted (%)		P value
		Non-new-onset diabetes (n = 7204)	New-onset diabetes (n = 2222)
Depression	1909 (20.3)	19.0	22.5	0.002
Overweight	6226 (66.1)	60.6	83.3	< 0.001
Ethnicity				< 0.001
Hispanic	555 (5.9)	3.9	7.1
Others	8871 (94.1)	96.1	92.9
Degree				< 0.001
Bachelor's degree and above	2217 (23.5)	26.9	20.9
Others	7209 (76.5)	73.1	79.1
Male	3837 (40.7)	42.4	46.5	0.003
Age (year)				< 0.001
≥ 75	1466 (15.6)	16.7	8.5
< 75	7960 (84.4)	83.3	91.5
Smoke	1744 (18.5)	20.9	23.0	0.091
Drink	5204 (55.2)	60.1	53.5	< 0.001
Marital	6501 (68.7)	66.5	67.1	0.674
Exercise	4670 (49.5)	51.5	46.4	< 0.001

Data were reported in n (%). P value derived from χ² test, and noted that weighted result.

Table 2 Odds ratios of depression and overweight for increased risk of new-onset diabetes

Characteristic	Unadjusted model		Adjusted model
	OR (95%CI)	P value	OR (95%CI)	P value
Depression	1.29 (1.16-1.44)	< 0.001	1.18 (1.03-1.35)	0.014
Overweight	3.24 (2.87-3.66)	< 0.001	3.11 (2.70-3.58)	< 0.001

Adjusted model: Adjustment for traditional risk factors, including age, sex, ethnicity, education level, smoking status, drinking status, marital status, exercise status, appetite loss, and appetite increase. OR: Odds ratio; 95%CI: 95% confidence interval.

Table 3 Mediation effect of overweight for depression to increased risk of new-onset diabetes

	β (SD)	OR (95%CI)	P value
Model A (overweight as the outcome)
Depression	0.18 (0.06)	1.20 (1.06-1.36)	0.004
Model B (new-onset diabetes as the outcome)
Overweight	1.13 (0.07)	3.10 (2.69-3.57)	< 0.001
Model C (new-onset diabetes as the outcome)
Depression	0.13 (0.07)	1.14 (1.00-1.30)	0.053
Sobel test for mediation effect			0.003

Model A was adjusted for the variables listed in the adjusted model in Table 2. Model B was further adjusted for depression in addition to the variables listed in the adjusted model in Table 2. Model C was further adjusted for overweight in addition to the variables listed in the adjusted model in Table 2. OR: Odds ratio; 95%CI: 95% confidence interval.