Table 1

Characteristics of participants by quartiles of SD of hemoglobin A1C in the Look AHEAD study

Entire
sample, N=3560
Quartiles of SD of hemoglobin A1C, %P value
Q1 (<0.259),
n=900
Q2 (0.259–0.430),
n=884
Q3 (0.430–0.697),
n=887
Q4 (>0.697),
n=889
At baseline
 Age, years58.4 (6.7)59.5 (6.7)59.2 (6.6)58.3 (6.6)56.6 (6.4)<0.001
 Women, %62.166.360.359.062.70.008
 Randomization arm, %0.632
  Diabetes support and education48.949.849.349.547.0
  Intensive lifestyle intervention51.150.250.750.553.0
 Race/ethnicity, %0.001
  Caucasian67.070.269.166.462.2
  Non-Hispanic black17.116.016.217.318.8
  Hispanic12.610.410.413.116.3
 Body mass index, kg/m236.0 (5.9)35.2 (5.9)35.6 (6.0)36.3 (5.7)36.9 (6.0)<0.001
 Current smoking, %3.73.22.74.04.70.122
 Alcohol drinking, %33.434.933.433.631.60.533
 Use of antihypertensive medication, %70.970.970.471.770.80.938
 Duration of diabetes, years5.0 (2.0–9.0)4.0 (1.0–7.0)4.0 (2.0–8.0)5.0 (2.0–10.0)6.0 (3.0–10.0)<0.001
 eGFR, mL/min/1.73 m290.9 (15.7)89.2 (15.6)89.5 (15.5)91.0 (15.8)93.9 (15.6)<0.001
During follow-up
 Average systolic blood pressure, mm Hg125.6 (13.9)123.9 (13.7)124.7 (12.8)126.3 (14.2)127.5 (14.5)<0.001
 Average diastolic blood pressure, mm Hg68.4 (8.0)67.2 (7.8)68.5 (7.8)68.5 (8.2)69.5 (8.0)<0.001
 Average total-to-HDL cholesterol ratio4.2 (1.2)4.1 (1.2)4.1 (1.1)4.3 (1.2)4.5 (1.2)<0.001
 Fasting plasma glucose, mg/dL
  Baseline fasting plasma glucose, mg/dL151.4 (44.5)127.8 (26.1)140.0 (32.4)156.6 (39.4)181.5 (55.0)<0.001
  12-month fasting plasma glucose, mg/dL136.4 (41.7)122.3 (26.7)128.4 (32.0)139.7 (39.9)155.2 (54.8)<0.001
  24-month fasting plasma glucose, mg/dL140.0 (45.0)122.8 (25.5)131.0 (32.8)142.4 (41.6)164.0 (60.9)<0.001
  36-month fasting plasma glucose, mg/dL142.3 (45.6)124.7 (25.7)133.9 (32.6)144.7 (40.4)166.0 (63.4)<0.001
  Average fasting plasma glucose, mg/dL142.5 (33.9)124.4 (21.8)133.4 (26.1)145.8 (31.2)166.6 (38.3)<0.001
 Hemoglobin A1C, %
  Baseline hemoglobin A1C, %7.2 (1.1)6.4 (0.7)6.8 (0.7)7.4 (0.9)8.2 (1.3)<0.001
  12-month hemoglobin A1C, %6.8 (1.1)6.3 (0.7)6.5 (0.8)6.9 (1.0)7.5 (1.5)<0.001
  24-month hemoglobin A1C, %6.9 (1.3)6.4 (0.7)6.6 (0.8)7.0 (1.1)7.8 (1.7)<0.001
  36-month hemoglobin A1C, %7.0 (1.3)6.4 (0.7)6.7 (0.8)7.1 (1.1)7.9 (1.8)<0.001
  Average hemoglobin A1C, %7.0 (1.0)6.4 (0.7)6.7 (0.7)7.1 (0.9)7.8 (1.1)<0.001
  • Data are mean (SD), median (IQR), or proportion as appropriate.

  • AHEAD, Action for Health in Diabetes; eGFR, estimated glomerular filtration rate; HDL, high-density lipoprotein; hemoglobin A1C, glycosylated hemoglobin; Q, quartile.