Effect of insulin on the renal handling of glucose and Na+ in controls and patients with type 2 diabetes (T2D)*
| Controls | T2D | ANOVA | |||||
| Saline | Insulin | Saline | Insulin | P value† | P value‡ | P value§ | |
| Urine flow (mL/min) | 6.5 (3.6) | 7.1 (3.0) | 6.1 (2.8) | 8.1 (4.8)** | ns | 0.0012 | ns |
| Creatinine clearance (mL/min) | 163 (62) | 165 (61) | 148 (28) | 168 (32)¶ | ns | 0.0014 | ns |
| Glucose filtration rate (mmol/min) | 3.68 (1.51) | 3.55 (1.26) | 3.20 (0.64) | 3.61 (0.65)¶ | ns | – | 0.0352 |
| Glucose reabsorption (mmol/min) | 2.84 (1.25) | 2.64 (0.90) | 2.63 (0.68) | 2.94 (0.60) | ns | ns | 0.002 |
| Glucose excretion rate (mmol/min) | 0.69 (0.18) | 0.83 (0.41)¶ | 0.49 (0.32) | 0.53 (0.30) | 0.0071 | – | 0.0128 |
| Fractional glucose excretion (%) | 19.9 (7.5) | 25.4 (6.7)** | 16.2 (6.4) | 16.1 (6.4) | 0.0003 | – | 0.0064 |
| Na+ filtration rate (mEq/min) | 22.4 (11.5) | 22.6 (9.9) | 19.4 (4.7) | 22.0 (4.0)¶ | ns | – | 0.03 |
| Na+ excretion rate (mEq/min) | 0.26 (0.14) | 0.36 (0.26) | 0.17 (0.12) | 0.18 (0.07) | 0.0082 | – | (0.058) |
| Fractional Na+ excretion (%) | 1.12 (0.70) | 1.66 (1.31) | 0.88 (0.66) | 0.85 (0.24) | 0.0091 | ns | ns |
| K+ filtration rate (mEq/min) | 0.81 (0.35) | 0.71 (0.28)†† | 0.72 (0.15) | 0.74 (0.15) | ns | 0.01 | ns |
| K+ excretion rate (mEq/min) | 0.08 (0.06) | 0.04 (0.03)** | 0.06 (0.04) | 0.05 (0.01)†† | ns | 0.006 | ns |
| Fractional K+ excretion (%) | 8.4 (6.7) | 5.2 (2.0)†† | 9.1 (7.4) | 6.6 (1.5)†† | ns | 0.005 | ns |
*Entries are median (IQR).
†Group effect;
‡Period effect;
§Interaction (group×period) by repeated measures ANOVA.
¶P<0.001;
**P<0.01;
††P<0.05 for the paired comparison between saline and insulin by Wilcoxon signed-rank test in each group.
ANOVA, analysis of variance; ns, not significant.