Table 2. Primary and Secondary Outcomes.
| Verapamil (n = 43)a | Placebo (n = 38)a | Adjusted between-group difference (95% CI) |
P value | |
|---|---|---|---|---|
| Primary outcome | ||||
| Area under the curve values for C-peptide level at 52 wk from diagnosis of type 1 diabetes, geometriclike mean (SD), pmol/mLb | 0.65 (0.31) | 0.44 (0.30) | 0.14 (0.01 to 0.27)c | .04c |
| Secondary outcomes | ||||
| Hemoglobin A1c, mean (SD), % | 6.6 (1.0) [n = 43] | 6.9 (1.2) [n = 39] | −0.3 (−1.0 to 0.4)d | .65d |
| Continuous glucose monitoring outcomese | (n = 44) | (n = 37) | ||
| Time spent with glucose concentration in range, mean (SD), % | ||||
| 70-180 mg/dL | 74 (18) | 70 (21) | 2 (−9 to 13)d | .74d |
| 70-140 mg/dL | 51 (19) | 49 (21) | 0 (−12 to 11)d | .95d |
| Glucose concentration, mean (SD), mg/dL | 151 (27) | 159 (41) | −4 (−25 to 16)d | .74d |
| Time spent with glucose concentration, mean (SD), % | ||||
| >180 mg/dL | 25 (18) | 28 (21) | −2 (−13 to 9)d | .74d |
| >250 mg/dLf | 5 (6) | 8 (10) | −1 (−6 to 4) | .74 |
| <54 mg/dLf | 0.20 (0.24) | 0.24 (0.26) | −0.02 (−0.19 to 0.15) | .79 |
| <70 mg/dLf | 1.3 (1.2) | 1.6 (1.3) | −0.2 (−1.0 to 0.6) | .74 |
SI conversion factor: To convert glucose to mmol/L, multiply by 0.0555.
Had analyzable area under the curve C-peptide measurements at 52 weeks. Four participants in the verapamil group were missing data at 52 weeks (3 dropped out prior to 52 weeks and 1 did not complete a mixed-meal tolerance test due to a medical issue). Two participants in the placebo group were missing data at 52 weeks (1 dropped out prior to 52 weeks and 1 had an area under the curve C-peptide measurement that was unanalyzable).
Data on C-peptide level were obtained during a mixed-meal tolerance test from which the area under the curve was computed. The baseline values for the geometriclike means were 0.66 (SD, 0.20) pmol/mL in the verapamil group and 0.60 (SD, 0.22) pmol/mL in the placebo group. In individuals with type 1 diabetes, the level can decline to less than 0.05 pmol/mL, which represents the limit of assay detection.
All randomized participants with at least 1 analyzable C-peptide measurement were included in the primary outcome analysis. In the verapamil group, all 47 participants were included in the primary outcome analysis. In the placebo group, 40 of 41 participants were included in the primary outcome analysis because there was 1 participant without C-peptide measurements at baseline or follow-up. Data were estimated from a constrained, longitudinal, mixed-effects model including age, time from type 1 diabetes diagnosis to randomization, and intensity of care (intensive diabetes management or standard diabetes care) as fixed effects and clinical site as a random effect. Values of log(area under the curve + 1) at randomization, at 13 weeks, at 26 weeks, at 39 weeks, and at 52 weeks were included in the response.
Estimated from a longitudinal, mixed-effects model including age, time from type 1 diabetes diagnosis to randomization, and intensity of care (intensive diabetes management or standard diabetes care) as fixed effects and clinical site as a random effect. The 95% CIs and P values have been adjusted for multiplicity using the 2-step Benjamini-Hochberg procedure.
Computed from up to 288 glucose values per day over approximately 28 days at 12 months. The median number of glucose values per participant was 7751 (IQR, 7513-7918) in the verapamil group and 7836 (IQR, 7537-7926) in the placebo group.
Robust means and SDs are reported for these outcomes with a skewed distribution. Estimates and 95% CIs were calculated using robust regression with M estimation. The models adjusted for age, days from type 1 diabetes diagnosis to randomization, and intensity of care (intensive diabetes management or standard diabetes care) as covariates.