TABLE 3

Characteristics of intensive and conventional treatment group subjects with a mean A1C in the intervals 6.5–7.49, 7.5–8.49, and 8.5–9.49% during the DCCT

DCCT updated mean A1C
6.5–7.49%7.5–8.49%8.5–9.49%
ConventionalIntensivePConventionalIntensivePConventionalIntensiveP
n6135717116322934
Cohort0.71180.65960.6353
    Primary prevention28 (45.9)173 (48.5)87 (50.9)79 (48.5)111 (48.5)15 (44.1)
    Secondary intervention33 (54.1)184 (51.5)84 (49.1)84 (51.5)118 (51.5)19 (55.9)
Age (years)27.8 ± 6.528.1 ± 6.60.586327.5 ± 6.425.8 ± 7.80.050826.8 ± 6.820.8 ± 6.20.0000
Adolescents3 (4.9)28 (7.8)0.5982*13 (7.6)35 (21.5)0.000328 (12.2)14 (41.2)0.0000
Phase 352 (85.2)289 (81.0)0.4240147 (86.0)130 (79.8)0.1316177 (77.3)20 (58.8)0.0205
Duration of treatment (years)6.2 (1.5)6.5 (1.6)0.06726.3 (1.5)6.4 (1.7)0.76946.5 (1.7)7.2 (1.7)0.0380
Caucasian61 (100.0)347 (97.2)0.3699*168 (98.2)155 (95.1)0.1065219 (95.6)31 (91.2)0.2279*
Duration of type 1 diabetes (years)6.4 ± 4.65.8 ± 4.20.43786.0 ± 4.35.6 ± 4.10.40125.5 ± 4.15.3 ± 3.50.8448
Male sex35 (57.4)186 (52.1)0.445588 (51.5)73 (44.8)0.2222134 (58.5)19 (55.9)0.7715
A1C at eligibility (%)7.9 (1.0)9.0 (1.4)0.00008.2 (1.0)9.6 (1.4)0.00009.0 (1.5)10.6 (1.7)0.0000
DCCT updated mean A1C (%)7.1 (0.3)7.0 (0.3)0.01558.0 (0.3)7.9 (0.3)0.00119.0 (0.3)8.9 (0.3)0.1395
MBG at baseline (mmol/l)10.4 (3.4)12.8 (4.4)0.000111.3 (3.8)13.2 (4.4)0.000012.5 (4.0)16.4 (4.8)0.0000
DCCT updated MBG (mmol/l)9.8 (1.6)8.3 (1.1)0.000011.3 (1.5)9.5 (1.4)0.000012.5 (1.8)10.2 (1.9)0.0000
Baseline retinopathy0.8987*0.50780.1224*
No retinopathy28 (45.9)173 (48.5)87 (50.9)79 (48.5)111 (48.5)15 (44.1)
Micro-aneurysm21 (34.4)120 (33.6)50 (29.2)59 (36.2)64 (27.9)15 (44.1)
Very mild NPDR8 (13.1)47 (13.2)24 (14.0)18 (11.0)42 (18.3)2 (5.9)
≥Moderate NPDR4 (6.6)17 (4.8)10 (5.8)7 (4.3)12 (5.2)2 (5.9)
Nephropathy0.5444*0.02281.0000*
AER <4057 (93.4)339 (95.0)168 (98.2)152 (93.3)218 (95.2)33 (97.1)
(40≤AER<300)4 (6.6)18 (5.0)3 (1.8)11 (6.7)11 (4.8)1 (2.9)
Presence of clinical neuropathy3 (5.5)19 (6.0)1.0000*20 (13.2)15 (10.9)0.551430 (15.2)5 (17.9)0.7797*
  • Data are n (%) and means ± SE.

  • * P values from Fisher's exact test, where noted. Otherwise, χ2 test for proportions or Wilcoxon's rank-sum test for individual quantitative variables. Longitudinal normal error models were used for the updated MBG and updated mean A1C.

  • For each subject the mean over all quarterly follow-up visits was computed. Then the group mean was computed from the subject means.

  • ‡From a 1-day, seven-point capillary collection.