Table 2

Hours of work a day and the risks of impaired fasting glucose or type 2 diabetes among 1266 Japanese male office workers during 5 years of follow up

		Hours of work a day		Test for trend p value
		< 8.0	8.0–8.9	Test for trend p value		9.0–9.9	10.0–10.9	⩾11.0
Impaired fasting glucose or type 2 diabetes:
Cases	47	43	20	16	12
Person-years	1598	1516	1009	813	801
Rate/1000 person-years	29.4	28.4	19.8	19.7	15.0
Age adjusted relative risk	1.00	0.89	0.66	0.64	0.49	0.013
(95% CI)	(Reference)	(0.59 to 1.36)	(0.37 to 1.19)	(0.38 to 1.10)	(0.25 to 0.96)
Multivariate adjusted relative risk^2-150	1.00	0.82	0.69	0.63	0.50	0.020
(95% CI)	(Reference)	(0.54 to 1.26)	(0.38 to 1.26)	(0.37 to 1.09)	(0.25 to 0.98)
Impaired fasting glucose:
Cases	29	25	14	11	8
Person-years	1631	1542	1015	822	808
Rate/1000 person-years	17.8	16.2	13.8	13.4	9.9
Age adjusted relative risk	1.00	0.86	0.78	0.76	0.57	0.167
(95% CI)	(Reference)	(0.50 to 1.47)	(0.38 to 1.60)	(0.40 to 1.46)	(0.25 to 1.28)
Multivariate adjusted relative risk^2-150	1.00	0.74	0.77	0.69	0.61	0.202
(95% CI)	(Reference)	(0.43 to 1.28)	(0.37 to 1.62)	(0.35 to 1.33)	(0.26 to 1.40)
Type 2 diabetes:
Cases	20	19	6	5	4
Person-years	1651	1577	1048	838	824
Rate/1000 person-years	12.1	12.0	5.7	6.0	4.9
Age adjusted relative risk	1.00	0.91	0.46	0.43	0.36	0.014
(95% CI)	(Reference)	(0.48 to 1.72)	(0.17 to 1.26)	(0.17 to 1.10)	(0.12 to 1.11)
Multivariate adjusted relative risk^2-150	1.00	0.90	0.50	0.49	0.30	0.014
(95% CI)	(Reference)	(0.46 to 1.74)	(0.18 to 1.42)	(0.19 to 1.26)	(0.09 to 0.94)

↵2-150 Adjusted for age, occupation, position, body mass index, cigarette smoking, alcohol intake, eating breakfast, vegetable consumption, fruit consumption, regular physical exercise, family history of diabetes, systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, high density lipoprotein cholesterol, and triglycerides at entry.