Table 1

Clinical characteristics of the former DCCT INT and CONV participants at DCCT baseline, DCCT closeout, and EDIC years 15–18

DCCT baseline (1983–1989) (n = 1,441)End of DCCT (1993) (n = 1,423)EDIC years 15–18 (2007–2012) (n = 1,214)
INTCONVINTCONVINTCONV
n711730701722606608
Medical history
 Age (years)27.2 (7.1)26.7 (7.1)33.6 (7.0)33.0 (7.0)50.9 (7.2)49.9 (7.0)
 Female (%)48.545.948.946.048.846.9
 Diabetes duration (years)5.8 (4.2)5.5 (4.1)12.3 (4.9)11.9 (4.8)29.3 (5.3)28.7 (5.4)
 DCCT primary cohort (%)49.051.849.251.748.450.8
 Hypertension (%)§3.12.14.43.962.466.0
 Hyperlipidemia (%)22.823.425.829.964.566.8
 Current cigarette smoking (%)18.618.420.319.812.212.2
Medical treatment
 Glucose management
  Pump or multiple daily injections (≥3) (%)0097.25.198.296.1
  Glucose monitoring ≥4 times a day (%)0052.63.766.870.2
 Use of ACE inhibitor or ARB (%)0053.057.6
Physical examination
 BMI (kg/m2)23.4 (2.7)23.5 (2.9)26.5 (4.2)25.0 (3.1)28.9 (5.6)28.2 (5.0)
 Obese (BMI ≥30 kg/m2) (%)1.31.918.55.735.631.4
 Systolic blood pressure (mmHg)114.5 (11.3)114.6 (11.4)116.3 (11.7)115.3 (12.0)121.1 (14.5)120.4 (14.7)
 Diastolic blood pressure (mmHg)73.1 (8.2)72.9 (8.7)74.4 (8.8)74.2 (8.8)71.7 (9.0)71.3 (8.8)
 Mean arterial pressure (mmHg)86.9 (8.2)86.8 (8.6)88.3 (8.9)87.9 (8.9)88.1 (9.5)87.7 (9.4)
Laboratory values
 HbA1c (%)#9.1 (1.6)9.1 (1.6)7.2 (0.9)9.1 (1.3)8.0 (1.1)8.0 (1.0)
  mmol/mol76 (17.5)76 (17.5)55 (9.8)76 (14.2)64 (12.0)64 (10.9)
 Plasma lipids (mg/dL)
  Total cholesterol177.1 (32.8)175.7 (33.6)178.9 (31.3)183.7 (36.9)175.4 (36.2)172.5 (38.5)
  HDL cholesterol50.8 (12.3)50.3 (12.3)50.8 (12.8)51.6 (12.9)61.3 (19.4)61.6 (18.3)
  LDL cholesterol110.3 (28.7)109.1 (29.4)111.7 (27.3)114.6 (31.5)97.3 (29.5)94.4 (30.5)
  Triglycerides80.8 (43.3)81.8 (51.3)81.9 (51.5)88.3 (54.5)84.4 (54.9)83.4 (76.7)
Complications
 Eye
  Retinopathy levels (%)
  No retinopathy (10/10)48.951.828.317.210.84.8
  MA only (20/<20)35.127.839.732.136.926.2
  Mild NPDR (35/<35)11.615.221.328.520.218.1
  Moderate NPDR (43/<43 – 53/53)4.55.18.314.416.519.7
  SNPDR or worse (53/<53 +)00.12.67.815.531.2
 Renal
  Sustained AER >30 mg/24 h5.24.37.614.513.520.6
  AER >300 mg/24 h001.43.24.07.4
  Sustained eGFR <60 mL/min/1.73 m2 (%)000.10.43.95.4
  • Data presented as mean (SD) or percent. Retinopathy or CSME assessments by fundus photography were completed for 1,423 subjects at DCCT closeout and 1,259 subjects between EDIC years 15 and 18. Each subject was assessed once every 4 years timed to the year of entry into the DCCT and all subjects assessed at 4 and 10 years.

  • P < 0.05 by the Wilcoxon rank sum test for quantitative outcomes, χ2 test for categorical outcomes, or Armitage trend test for ordinal outcomes (retinopathy) comparing conventional and intensive treatment.

  • P < 0.01 by the Wilcoxon rank sum test for quantitative outcomes, χ2 test for categorical outcomes, or Armitage trend test for ordinal outcomes (retinopathy) comparing conventional and intensive treatment.

  • § Hypertension was defined by systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or use of antihypertensive medications.

  • Hyperlipidemia was defined by an LDL cholesterol level ≥130 mg/dL (3.4 mmol/L) or the use of lipid-lowering agents.

  • Medication usage was not recorded during the DCCT. Use of ACE inhibitors was proscribed during the DCCT. At EDIC year 1, ACE inhibitor use was 5.6% in INT and 6.9% in CONV. ARBs were not available until later during EDIC.

  • # End of DCCT HbA1c is the mean HbA1c throughout the DCCT; EDIC years 15–18 HbA1c values are time-averaged values through EDIC to the years 15–18 visit. The time-averaged mean (SD) HbA1c levels through DCCT and EDIC combined were 7.8% (0.9) and 8.3% (1.0) (62 [9.8] and 67 [10.9] mmol/mol) among participants assigned to intensive and conventional diabetes therapy, respectively. ARB, angiotensin II receptor blocker; eGFR, estimated glomerular filtration rate; MA, microaneurysms; NPDR, nonproliferative diabetic retinopathy.