Table 1.
Characteristics of nonproteinuric patients with type 1 diabetes according to whether renal function was stable during 4–6 years of follow-up or early GFR loss developed
| Characteristic* | Stable renal function | Early GFR loss | P value |
|---|---|---|---|
| n | 276 | 79 | |
| Baseline characteristics | |||
| % men | 55 | 56 | 0.92 |
| Age at diabetes diagnosis (years) | 17 ± 10 | 20 ± 11 | 0.02 |
| Duration of diabetes (years) | 21 ± 9 | 24 ± 10 | 0.02 |
| Age (years) | 38 ± 12 | 44 ± 11 | <0.0001 |
| A1C (%) | 8.2 (7.4–9.1) | 8.3 (7.6–9.5) | 0.17 |
| Insulin dose (units/kg/day) | 0.63 (0.53–0.83) | 0.64 (0.48–0.86) | 0.83 |
| BMI (kg/m2) | 26 (23–29) | 26 (24–32) | 0.15 |
| Serum cholesterol (mg/dl) | 184 (166–204) | 185 (167–204) | 0.96 |
| Serum HDL (mg/dl) | 54 (46–65) | 53 (46–64) | 0.74 |
| GFRcystatin (ml/min per 1.73 m2) | 131 (116–147) | 115 (93–136) | <0.0001 |
| ACR (mg/g) | 34.6 (22.2–63.8) | 51.6 (29.9–114.9) | <0.0001 |
| % with microalbuminuria | 56 | 75 | 0.003 |
| % with renoprotective treatment | 50 | 68 | 0.005 |
| Systolic blood pressure (mmHg) | 120 (111–128) | 122 (114–129) | 0.13 |
| Diastolic blood pressure (mmHg) | 70 (68–79) | 72 (68–77) | 0.60 |
| Cigarette smoking | |||
| % current | 18 | 13 | 0.18 |
| % past | 24 | 34 | |
| Serum uric acid (mg/dl) | 4.5 (3.7–5.3) | 5.10 (4.4–5.7) | <0.0001 |
| Follow-up characteristics | |||
| Duration of follow-up (years) | 4.8 (4.1–5.5) | 4.9 (3.9–5.7) | 0.56 |
| Number of cystatin determinations | 5 (4–6) | 5 (4–6) | 0.33 |
| Number of ACR determinations | 5 (4–7) | 6 (4–7) | 0.58 |
| Last GFRcystatin (ml/min per 1.73 m2) | 124 (109–139) | 86 (65–99) | By design |
| Percent change per year in GFRcystatin | −1.8 (−2.4 to −1.2) | −4.4 (−5.0 to −3.8) | By design |
| Progressed to CKD stage 3 or greater [n (%)] | 3 (1) | 19 (24) | <0.0001 |
| Last ACR (mg/g)† | 17.1 (9.8, 42.1) | 40.3 (13.8, 128.5) | <0.0001 |
| Progression of ACR [n (%)] | 48 (17) | 27 (34) | 0.001 |
| Regression of ACR [n (%)] | 103 (73) | 26 (33) | 0.47 |
Data are medians (25th–75th percentiles) and P values from Wilcoxon rank sum test for continuous variables (except for age at diabetes diagnosis, duration, and age, which are means ± SD and t tests) and percents with P values from χ2 test for categorical data.
*Values for A1C, serum cholesterol, serum HDL, and ACR were the medians of all determinations during the 2-year interval ending with the entry examination.
†Median of all ACR measurements in the second 2-year follow-up interval.