Table 1

Characteristics of adults with diabetes and routine access to care by conventional metformin eligibility status, NHANES 1999–2010

FDA ineligible:
sCr >1.4 mg/dL for women;
>1.5 mg/dL for men
FDA eligible:
sCr ≤1.4 mg/dL for women;
≤1.5 mg/dL for men
P2 or ANOVA)
Of study
N = 342
Of national estimate N = 1,328,400Of study
N = 3,269
Of national estimate N = 16,308,600
Male sex199 (58.2)682,0721,641 (50.2)8,126,6610.63
Age (years)<0.001
 20–393 (0.9)13,763206 (6.3)1,518,262
 40–5936 (10.5)178,8581,003 (30.7)6,800,049
 60–69107 (31.3)388,3651,041 (31.8)4,071,965
 70+196 (57.3)747,3691,019 (31.2)3,918,311
Race/ethnicity**0.0007
 White142 (41.5)835,9911,294 (39.6)10,394,879
 Non-Hispanic black124 (36.3)314,372817 (25.0)2,510,790
 Mexican American58 (17.0)69,714766 (23.4)1,273,053
Yearly family income ($)0.0001
 <20,000124 (40.4)456,578954 (32.4)3,606,754
 20,000–44,999122 (39.7)477,2041,051 (35.6)5,202,546
 45,000–74,99941 (13.4)164,698531 (18.0)3,082,007
 >75,00020 (6.5)109,762419 (14.2)3,061,184
Has health insurance327 (95.61)1,276,535408 (12.6)14,491,1850.01
More than high school education137 (50.6)632,0301,431 (55.9)9,133,4410.007
Hypertension*267 (78.8)1,058,5912,036 (67.7)9,615,947<0.001
Glycemic control: A1C0.22
 <7% (<53 mmol/mol)200 (58.7)817,3511,735 (53.2)8,890,542
 7–<8% (53–63 mmol/mol)74 (21.7)284,722688 (21.1)3,389,353
 8–<9% (64–74 mmol/mol)33 (9.7)104,007330 (10.1)1,565,172
 ≥9% (>75 mmol/mol)34 (10.0)119,576509 (15.6)2,432,187
BMI (kg/m2), mean (SD)32.6 (8.2)33.02 (0.5)32 (7.1)32.65 (0.2)0.51
MDRD eGFR (mL/min/1.73 m2), mean (SD)32.8 (12.6)32.99 (0.7)84.94 (25.4)84.47 (0.5)<0.001
Urine albumin-to-creatinine ratio (mg/g)<0.001
 ≤30103 (33.9)439,8362,187 (68.4)11,556,713
 31–299111 (36.5)434,403788 (24.7)3,585,717
 300–1,00033 (10.9)128,431151 (4.7)572,633
 >1,00057 (18.8)210,05271 (2.2)287,114
  • Data are n (%) or n unless otherwise indicated. Sample weights used to produce U.S. national estimates. Diabetes is self-reported or A1C ≥6.5%. Entire sample size = 3,902; sCr data are missing from 291 study participants.

  • *Hypertension defined by average blood pressure >140/90 mmHg or self-reported antihypertensive medication use.

  • **“Other” not shown owing to small sample size but included in all analyses.