TABLE 1.
Baseline characteristics of participants in the depletion–repletion study and in the cross-sectional study of renal leak in diabetes1
| Cross-sectional cohort studies of vitamin C renal leak | Vitamin C depletion/repletion study (n = 17) | ||
|---|---|---|---|
| Characteristic | Nondiabetic control (n = 80) | Diabetes cohort (n = 82) | |
| Demographics | |||
| Race | |||
| White/Caucasian | 35 (43.8) | 34 (41.5) | 14 (82.4) |
| Black/African American | 36 (45) | 36 (43.9) | 2 (11.8) |
| Other2 | 9 (11.2) | 12 (14.6) | 1 (5.9) |
| Sex | |||
| Male | 30 (37.5) | 40 (48.8) | 7 (41.2) |
| Female | 50 (62.5) | 42 (51.2) | 10 (58.8) |
| Age, mean ± SD, y | 33.5 ± 12.6* | 49.2 ± 12.1* | 22 ± 2 |
| BMI, mean ± SD, kg/m2 | 27.5 ± 5.7* | 32.5 ± 6.7* | 26 ± 11.5 |
| Clinical and laboratory variables | |||
| Renal function | |||
| PCR, mean ± SD, mg/mg | 0.097 ± 0.091* | 0.267 ± 0.557* | NA |
| eGFR,3 mean ± SD, mL/min/1.73 m2 | 112.8 ± 21.1 | 101.6 ± 26.2 | 94 ± 21.2 |
| Glycemic control | |||
| Fasting plasma glucose, mean ± SD, mg/dL | 88.3 ± 8.8* | 147.0 ± 53.3* | 88 ± 4.6 |
| Hemoglobin A1c, mean (SD), % | 5.37 (0.4)* | 7.9 (1.4)* | NA |
| Diabetes history | |||
| Diabetes type | |||
| Type 1 | 21 (25) | ||
| Type 2 | 61 (75) | ||
| Duration of diagnosis, mean ± SD, y | 11.5 ± 11.3 | ||
| Micro- or macrovascular disease | 20 (23.8) | ||
| Medication4 | |||
| Antihypertensives | 45 (53.6) | ||
| Diuretics5 | 15 (17.9) | ||
| ACE/ARB | 41 (48.8) | ||
Values are presented as number (%) unless otherwise indicated. Asterisks indicate that variables are statistically different (P < 0.05, nondiabetic control compared with diabetes cohort, Welch t test). ACE, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; eGFR, estimated glomerular filtration rate; NA, data non available; PCR, protein/creatinine ratio.
The subgroup “Other” is composed of Asian, Hispanic, and Latino and multiracial participants. Racial categories were based on NIH reporting guidelines on racial and ethnic categories (NOT-OD-15-089).
eGFR for all groups was calculated using the Modification of Diet in Renal Disease v4 equation: [186 × (Creatinine / 88.4) – 1.154 × (Age) – 0.203 × (0.742 if female) × (1.210 if black)].
One participant was taking an SGLT2 inhibitor.
Includes loop diuretics, thiazides, and aldosterone antagonists.