Table 3

HRs (95% CIs) for atrial fibrillation (AF) by fasting serum glucose and HbA1c levels in individuals with type 2 diabetes (defined by history of medication use or self-report of diabetes; n=959) (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	2	18	156
Person-years	542	1675	9683
HR (95% CI) Model 1	1 (ref)	2.53 (0.58 to 11.0)	4.10 (1.01 to 16.7)	0.005	0.79	0.79
HR (95% CI) Model 2	1 (ref)	1.99 (0.46 to 8.67)	2.89 (0.71 to 11.8)	0.04	0.78	0.80
HR (95% CI) excluding prevalent CHD^*	1 (ref)	2.07 (0.47 to 9.05)	2.63 (0.64 to 10.7)	0.11	0.89	0.54

	HbA1c (%)				p Values for interactions
	<5.7	5.7–6.4	≥6.5	p Value for trend	Gender	Race
No of AF cases	8	16	152
Person-years	1135	1714	9049
HR (95% CI) Model 1	1 (ref)	1.30 (0.56 to 3.05)	2.77 (1.36 to 5.65)	0.0002	0.76	0.79
HR (95% CI) Model 2	1 (ref)	1.18 (0.50 to 2.77)	2.11 (1.02 to 4.37)	0.007	0.66	0.52
HR (95% CI) excluding prevalent CHD^*	1 (ref)	1.22 (0.49 to 3.05)	2.21 (1.01 to 4.83)	0.009	0.84	0.79
HR (95% CI) + adjustment for FSG^†	1 (ref)	1.12 (0.48 to 2.64)	1.69 (0.78 to 3.66)	0.09	0.73	0.56

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.
↵† HR (95% CIs) from model 2 plus adjustment for fasting serum glucose among all persons with type 2 diabetes.
CHD, coronary heart disease; FSG, fasting serum glucose.