Table 2

HRs (95% CIs) for atrial fibrillation (AF) by fasting serum glucose and HbA1c levels in individuals without type 2 diabetes (defined by no history of medication use or no self-report of diabetes; n=12 066) (Atherosclerosis Risk in Communities study, 1990–2007)

	Fasting serum glucose (mg/dl)				p Values for interactions
	<100	100–125	≥126	p Value for trend	Gender	Race
No of AF cases	405	626	104
Person-years	73 322	92 274	11 544
HR (95% CI) Model 1	1 (ref)	1.07 (0.94 to 1.21)	1.48 (1.19 to 1.84)	0.005	0.64	0.24
HR (95% CI) Model 2	1 (ref)	0.92 (0.81 to 1.05)	1.02 (0.82 to 1.28)	0.63	0.50	0.31
HR (95% CI) excluding cases of prevalent CHD^*	1 (ref)	0.90 (0.70 to 1.03)	0.92 (0.71 to 1.17)	0.20	0.82	0.21

	HbA1c (%)				p Values for interactions
	<5.7	5.7–6.4	≥6.5	p Value for trend	Gender	Race
No of AF cases	788	280	67
Person-years	136 022	33 695	7422
HR (95% CI) Model 1	1 (ref)	1.39 (1.21 to 1.60)	1.67 (1.30 to 2.15)	<0.0001	0.21	0.25
HR (95% CI) Model 2	1 (ref)	1.13 (0.98 to 1.30)	1.19 (0.92 to 1.54)	0.06	0.07	0.58
HR (95% CI) excluding prevalent CHD^*	1 (ref)	1.09 (0.94 to 1.27)	1.02 (0.76 to 1.36)	0.45	0.17	0.73

Model 1: adjusted for age, race and sex. Model 2: adjusted for model 1 + centre, education, income, smoking status, prevalent CHD, systolic blood pressure, hypertensive medications and body mass index.
↵* Excluding prevalent CHD: adjusted HR (Model 2) and 95% CIs after excluding those with prevalent CHD.
CHD, coronary heart disease.