Table 4.

Association of each component of the metabolic syndrome with work schedule

	Crude		Model 1		Model 2		Model 3
	OR (95% CI)	p-value	OR (95% CI)	p-value	OR (95% CI)	p-value	OR (95% CI)	p-value
High BP	n=2301		n=2274		n=2066		n=1731
Day shift-workers	0.92 (0.69 to 1.22)	0.572	1.05 (0.78 to 1.42)	0.746	1.02 (0.73 to 1.42)	0.907	1.06 (0.73 to 1.54)	0.757
Night shift-workers	1.19 (0.84 to 1.70)	0.321	1.02 (0.70 to 1.49)	0.912	0.92 (0.61 to 1.39)	0.682	1.01 (0.62 to 1.63)	0.983
Permanent night workers	1.58 (0.86 to 2.92)	0.144	1.78 (0.93 to 3.41)	0.081	1.60 (0.77 to 3.31)	0.204	1.90 (0.79 to 4.58)	0.155
High fasting glucose	n=2301		n=2274		n=2066		n=1731
Day shift-workers	0.89 (0.64 to 1.25)	0.504	1.05 (0.74 to 1.50)	0.776	1.07 (0.73 to 1.58)	0.735	1.04 (0.66 to 1.63)	0.883
Night shift-workers	1.64 (1.13 to 2.37)	0.009	1.36 (0.91 to 2.02)	0.135	1.44 (0.93 to 2.24)	0.106	1.26 (0.74 to 2.14)	0.389
Permanent night workers	1.87 (0.99 to 3.51)	0.052	2.14 (1.07 to 4.29)	0.031	1.70 (0.79 to 3.64)	0.173	1.31 (0.52 to 3.29)	0.572
High triglycerides
Men	n=1117		n=1116		n=1038		n=886
Day shift-workers	1.16 (0.71 to 1.88)	0.562	1.14 (0.70 to 1.87)	0.593	1.30 (0.77 to 2.19)	0.324	1.32 (0.73 to 2.40)	0.360
Night shift-workers	0.76 (0.44 to 1.30)	0.313	0.74 (0.43 to 1.28)	0.287	0.86 (0.49 to 1.52)	0.604	0.97 (0.52 to 1.84)	0.936
Permanent night workers	4.43 (1.70 to 11.56)	0.002	4.31 (1.64 to 11.30)	0.003	3.50 (1.19 to 10.26)	0.023	3.27 (0.99 to 10.77)	0.051
Women	n=1109		n=1105		n=1020		n=837
Day shift-workers	1.34 (0.76 to 2.37)	0.309	1.34 (0.75 to 2.38)	0.320	1.19 (0.63 to 2.24)	0.594	0.92 (0.41 to 2.03)	0.828
Night shift-workers	2.33 (1.09 to 4.99)	0.030	2.29 (1.06 to 4.95)	0.035	2.65 (1.14 to 6.15)	0.023	2.92 (1.03 to 8.27)	0.044
Permanent night workers	1.37 (0.40 to 4.68)	0.618	1.36 (0.39 to 4.73)	0.625	1.09 (0.30 to 3.97)	0.899	0.53 (0.06 to 4.32)	0.549
Low HDL-cholesterol	n=2226		n=2221		n=2058		n=1723
Day shift-workers	0.79 (0.50 to 1.29)	0.336	0.75 (0.46 to 1.23)	0.255	0.62 (0.28 to 1.40)	0.252	0.74 (0.39 to 1.39)	0.348
Night shift-workers	0.67 (0.35 to 1.30)	0.240	0.60 (0.31 to 1.18)	0.138	0.58 (0.29 to 1.15)	0.116	0.66 (0.30 to 1.45)	0.300
Permanent night workers	2.22 (1.05 to 4.71)	0.038	1.90 (0.89 to 4.08)	0.099	1.61 (0.71 to 3.64)	0.252	1.47 (0.52 to 4.18)	0.468
Visceral obesity
Men	n=1119		n=1118		n=1043		n=890
Day shift-workers	0.74 (0.42 to 1.29)	0.288	0.75 (0.42 to 1.34)	0.333	0.84 (0.47 to 1.51)	0.561	0.72 (0.36 to 1.42)	0.341
Night shift-workers	1.18 (0.71 to 1.94)	0.525	1.11 (0.66 to 1.84)	0.704	1.06 (0.61 to 1.85)	0.257	0.84 (0.44 to 1.63)	0.612
Permanent night workers	5.06 (1.94 to 13.22)	0.001	5.27 (1.99 to 13.98)	0.001	4.79 (1.64 to 14.03)	0.004	3.35 (1.04 to 10.76)	0.042
Women	n=1108		n=1104		n=1022		n=839
Day shift-workers	1.47 (1.01 to 2.14)	0.043	1.48 (1.01 to 2.17)	0.043	1.31 (0.87 to 1.97)	0.194	1.05 (0.65 to 1.70)	0.852
Night shift-workers	1.70 (0.93 to 3.06)	0.086	1.79 (0.98 to 3.29)	0.059	1.91 (1.01 to 3.62)	0.047	1.51 (0.66 to 3.10)	0.324
Permanent night workers	1.70 (0.75 to 3.84)	0.203	1.69 (0.73 to 3.92)	0.219	1.75 (0.72 to 4.23)	0.217	0.83 (0.23 to 2.99)	0.971

Data are presented as OR and 95% confidence intervals (CI). For each component analysed, the ‘permanent day workers’ were considered as the reference group. p-values<0.05 are in bold. Model 1 was adjusted for age (continuous), age square (continuous), sex (except for sex subanalysis) and educational level (middle, low, high). Model 2 was additionally adjusted for weekly alcohol consumption (continuous), smoking status (never, former, current) and for BMI (normal weight, overweight, obese) (except for visceral obesity). Model 3 was additionally adjusted for daily total energy expenditure (continuous).

BMI, body mass index; BP, blood pressure; HDL, high-density lipoprotein.