Table 2.
Comparison of metabolic parameters by glucose response curve shape
| All | Monophasic | Biphasic | Continuous rise | Overall p value | M vs B | M vs C | B vs C | |
| P value | P value | P value | ||||||
| n | 3108 | 2107 | 172 | 829 | ||||
| HbA1c (%) | 7.50 (0.48) | 7.49 (0.48) | 7.49 (0.48) | 7.52 (0.49) | 0.032 | 0.900 | 0.022 | 0.613 |
| HbA1c (% mmol/mol) | 58.4 (5.3) | 58.4 (5.2) | 58.4 (5.2) | 58.7 (5.4) | 0.032 | 0.900 | 0.022 | 0.613 |
| Fasting glucose (mmol/L) | 8.42 (1.71) | 8.48 (1.73) | 8.24 (1.50) | 8.31 (.70) | 0.734 | 0.703 | 0.984 | 0.778 |
| 2-hour glucose (mmol/L) | 15.98 (3.06) | 15.42 (2.98) | 15.63 (2.71) | 17.46 (2.85) | <0.001 | 0.965 | <0.001 | <0.001 |
| Peak glucose (mmol/L) | 17.69 (2.87) | 17.87 (2.88) | 16.40 (2.42) | 17.48 (2.85) | <0.001 | <0.001 | <0.001 | <0.001 |
| Proportions with peak glucose at OGTT time-point, n (%) | <0.001 | <0.001 | <0.001 | <0.001 | ||||
| 30 min | 21 (0.7) | 9 (0.4) | 12 (7.0) | 0 (0.0) | ||||
| 60 min | 793 (25.5) | 721 (34.2) | 61 (35.5) | 11 (1.3) | ||||
| 90 min | 1536 (49.4) | 1377 (65.4) | 19 (11.0) | 140 (16.9) | ||||
| 120 min | 758 (24.4) | 0 (0.0) | 80 (46.5) | 678 (81.8) | ||||
| Mean time to peak glucose (min) | 89.3 (21.7) | 79.5 (14.6) | 89.1 (31.5) | 114.1 (12.9) | <0.001 | <0.001 | <0.001 | <0.001 |
| Mean incAUCglu (mmol/L) | 6.3 (1.6) | 6.5 (1.5) | 5.3 (1.6) | 5.9 (1.5) | <0.001 | <0.001 | <0.001 | <0.001 |
| HOMA2-S model (%) | 56.5 (40.6) | 53.2 (38.) | 60.9 (41.5) | 63.9 (45.6) | 0.077 | 0.979 | 0.058 | 0.588 |
| Fasting insulin (pmol/L) | 128.9 (89.0) | 135.3 (91.7) | 119.6 (81.4) | 114.5 (81.4) | 0.742 | 0.976 | 0.755 | 0.841 |
| Insulinogenic index (nmol/mol)* | 36.5 (30.2) | 36.4 (29.0) | 44.1 (37.0) | 35.3 (31.5) | <0.001 | <0.001 | 0.327 | <0.001 |
| Late insulin response (pmol/mol)* | 40.4 (34.8) | 42.4 (36.7) | 46.3 (39.8) | 34.0 (27.2) | <0.001 | 0.033 | <0.001 | <0.001 |
| incAUCins/incAUCglu (nmol/mol)* | 39.1 (31.5) | 40.5 (32.6) | 45.9 (36.5) | 34.0 (23.6) | <0.001 | 0.001 | 0.008 | <0.001 |
| Fasting C peptide (nmol/L) | 1.35 (0.56) | 1.40 (0.57) | 1.26 (0.49) | 1.23 (0.53) | 0.060 | 0.656 | 0.049 | 0.927 |
| C peptide index (nmol/mmol)* | 0.135 (0.096) | 0.134 (0.089) | 0.155 (0.119) | 0.133 (0.106) | 0.003 | 0.002 | 0.646 | 0.014 |
| incAUC-CP/incAUCglu (µmol/mol)* | 0.19 (0.11) | 0.19 (0.11) | 0.22 (0.13) | 0.17 (0.09) | <0.001 | 0.002 | <0.001 | <0.001 |
| C peptide/insulin (µmol/pmol) | 12.5 (4.6) | 12.3 (4.4) | 12.7 (4.4) | 13.0 (5.1) | 0.070 | 0.442 | 0.075 | 0.999 |
Mean (SD).
All comparisons were adjusted for sex, age, race, BMI, diabetes duration, eGFR, and metformin dose.
*Insulin and C peptide responses were further adjusted for HOMA2-S.
B, biphasic shape; BMI, body mass index; C, continuous rise shape; eGFR, estimated glomerular filtration rate; HbA1c, hemoglobin A1c; HOMA2-S, homeostasis model of insulin sensitivity; incAUC-CP, incremental area under curve C peptide; incAUCglu, incremental area under curve glucose; incAUCins, incremental area under curve insulin; M, monophasic shape; OGTT, oral glucose tolerance test.