Table 1.

Population characteristics by diabetes status, NHANES 1999 through 2006

Characteristic	Diabetes Status				Pa
	Diagnosed Diabetes	Undiagnosed Diabetes	Prediabetes	No Diabetes
n	826	299	2272	4791	—
Mean FPG (mg/dl)	153.0	166.5	107.1	90.7	<0.001
Mean glycohemoglobin (%)	7.21	7.04	5.49	5.23	<0.001
Mean age (years)	57.7	58.8	52.0	42.4	<0.001
Gender (%)					<0.001
male	48.4	63.0	59.9	43.9
female	51.6	37.0	40.1	56.1
Race/ethnicity (%)b					<0.001
non-Hispanic white	61.7	74.0	74.2	72.3
non-Hispanic black	15.1	11.8	7.8	11.4
Mexican American	8.4	6.6	7.7	7.1
Education (%)					<0.001
less than high school	29.0	31.7	22.8	16.6
high school or more	71.0	68.3	77.2	83.4
Household income (%)					<0.001
<$20,000	26.6	24.1	18.3	15.0
$20,000–$44,999	35.6	43.4	29.1	28.5
$45,000–$74,999	20.1	15.9	26.6	26.7
≥$75,000	17.7	16.6	26.1	29.8
Insurance (%)					<0.001
not insured	8.9	16.8	17.3	19.4
insured	91.1	83.2	82.7	80.6
Routine site for health care (%)					<0.001
no	2.5c	10.3	15.8	16.5
yes	97.5	89.7	84.2	83.5
Smoking (%)					0.020
every day	18.6	17.4	19.0	22.3
sometimes/not at all	81.4	82.6	81.0	77.7
BMI (kg/m2; %)					<0.001
≥30	55.3	55.1	39.7	24.6
<30	44.7	44.9	60.3	75.4
Self-reported hypertension (%)					<0.001
yes	60.3	54.6	36.6	20.9
no	39.7	45.2	63.4	79.1
ACEIs/ARBs (%)					<0.001
yes	20.8	11.0	7.5	3.0
no	79.2	89.0	92.5	97.0

Diagnosed diabetes, self-reported of diabetes diagnosis; undiagnosed diabetes, FPG ≥126 mg/dl and no self-report of diabetes; prediabetes, FPG ≥100 and <126 mg/dl and no self-report of diabetes; no diabetes, FPG <100 mg/dl and no self-report of diabetes. BMI, body mass index.

^aAcross all four groups of diabetes status, by χ² (categorical variables) and Kruskal-Wallis (continuous variables) tests.

^bOther race/ethnicity not shown because of small sample sizes, but individuals in category are included in all analyses.

^cUnreliable estimate: Relative SE ≥30%.