Table 1.

Characteristics of NHANES 1999–2006 study participants by A1C and fasting glucose

	A1C <5.7%		A1C ≥5.7%
	FPG <100 mg/dl	FPG ≥100 mg/dl	FPG <100 mg/dl	FPG ≥100 mg/dl
n	4,439	1,430	446	714
Age (years)	40.8 ± 0.4	49.1 ± 0.6	54.0 ± 0.9	58.1 ± 0.6
Women (%)	57.8	36.0	54.2	51.3
Race/ethnicity
Non-Hispanic white (%)	76.2	80.8	62.5	71.7
Non-Hispanic black (%)	11.2	5.6	25.5	15.2
Hispanic (%)	7.5	8.3	8.2	7.0
Current smoker (%)	25.8	22.2	27.1	20.7
Systolic blood pressure (mmHg)	118.3 ± 0.4	125.9 ± 0.6	129.9 ± 1.1	130.7 ± 0.8
Diastolic blood pressure (mmHg)	70.5 ± 0.3	72.5 ± 0.4	72.2 ± 0.7	71.8 ± 0.7
Hypertension (%)	18.1	34.2	40.8	53.4
BMI (kg/m2)	26.8 ± 0.1	29.4 ± 0.3	29.9 ± 0.4	31.4 ± 0.4
Waist circumference (cm)	92.1 ± 0.3	101.0 ± 0.6	101.2 ± 1.0	105.4 ± 0.7
Total cholesterol (mg/dl)	198.0 ± 0.9	205.1 ± 1.4	211.7 ± 2.5	207.6 ± 2.1
HDL cholesterol (mg/dl)	55.1 ± 0.3	50.0 ± 0.6	51.1 ± 0.9	49.5 ± 0.7
Triglycerides (mg/dl)	102 (73–149)	134 (91–192)	129 (90–188)	136 (101–195)
eGFR <60 ml/min per 1.73m2 (%)	6.1	8.7	12.3	15.5
Microalbuminuria (%)	5.6	8.3	13.1	13.3
Hemoglobin (g/dl)	14.4 ± 0.1	15.0 ± 0.1	14.3 ± 0.1	14.6 ± 0.1
Serum albumin (g/dl)	4.30 ± 0.01	4.32 ± 0.01	4.17 ± 0.03	4.18 ± 0.02
Ferritin (ng/ml)	56 (28–111)	104 (51–193)	81 (32–159)	93 (45–173)
Aspartate aminotransferase (units/l)	24.2 ± 0.3	26.5 ± 0.5	27.1 ± 1.7	25.6 ± 0.4
Alanine aminotransferase (units/l)	24.3 ± 0.3	30.3 ± 1.8	28.7 ± 2.1	27.9 ± 0.8
C-reactive protein ≥2 mg/l (%)	45.4	55.2	65.0	69.5
Fasting plasma glucose (mg/dl)	90.2 ± 0.2	106.1 ± 0.2	93.3 ± 0.3	109.6 ± 0.4
A1C (%)	5.2 (5.0–5.3)	5.3 (5.1–5.5)	5.8 (5.7–5.9)	5.9 (5.8–6.0)

Data are ± SE, %, or median (25th–75th percentiles). eGFR, estimated glomerular filtration rate.