Secular Trends of the Impact of Overweight and Obesity on Hypertension in Yi People: Yi Migrant Study, 1996–2015

Table 3

Interactions between overweight/obesity and time period among Yi people in association with risk of hypertension, Yi Migrant Study, 1996–2015^a.

	P2 vs. P1		P3 vs. P1		P3 vs. P2
	OR	95% CI	OR	95% CI	OR	95% CI
Main effects
Overweight/obesity (BMI^b ≥24)	2.85	1.70, 4.74	2.99	1.78, 4.99	3.56	2.75, 4.60
Time period	1.46	1.02, 2.14	1.75	1.22, 2.58	1.50	1.17, 1.91
Joint effect	4.90	3.38, 7.24	5.15	3.62, 7.50	4.21	3.35, 5.29
Relative excess risk due to interaction (RERI)	1.59	0.12, 3.05	1.41	0.30, 2.78	0.15	−0.76, 1.07
value	0.017		0.027		0.372
Attributable proportion, %
Overweight/obesity (BMI ≥24)	47.41	16.65, 78.17	47.91	17.71, 78.10	79.78	54.50, 105.06
Time period	11.88	1.56, 22.19	18.14	8.00, 28.28	15.46	6.14, 24.78
Additive interaction	40.71	6.62, 74.81	33.95	8.57, 67.04	4.76	−23.37, 32.88
Multiplicative interaction	1.18	0.67, 2.07	0.98	0.57, 1.72	0.79	0.57, 1.10

P1: period 1; P2: period 2; P3: period 3; CI: confidence interval; OR: odds ratio; BMI: body mass index. a: all models were adjusted for age, sex, education, and smoking. b: weight (kg)/height (m)².