Verapamil improves One-Year C-Peptide Levels in Recent Onset Type-1 Diabetes: A Meta-Analysis

Meta-analysis studying the role of verapamil in improving C-peptide in people with recent-onset type-1 diabetes (T1DM) has not been conducted to date. We undertook this meta-analysis to address this knowledge gap. Electronic databases were systematically reviewed for RCTs having individuals with T1DM receiving verapamil in the treatment arm and placebo in the control arm over the standard of care. The primary outcome was to evaluate changes in the C-peptide area under the curve (AUC) at a one-year follow-up. Secondary outcomes were to assess alterations in C-peptide AUC, glycated hemoglobin (HbA1c), blood pressure, heart rate, and side effects at different time intervals over a one-year follow-up. From the initially screened 27 articles, data from two RCTs (112 patients) satisfied the inclusion criteria and were analyzed. Compared to placebo, C-peptide AUC in individuals receiving verapamil was not different at three months [MD 0.17 nmol/L (95%CI: -0.05-0.38); P = 0.13; I(2) = 86%] but significantly higher at 1-year [MD 0.27 nmol/L (95%CI: 0.19–0.35); P < 0.01; I(2) = 12%]. The verapamil arm showed similar changes in HbA1C at three months [MD 0.23% (95%CI: -0.43–0.90); P = 0.49; I(2) = 88%] and 1-year [MD 0.18% (95% CI: -0.74 – 1.10); P = 0.70; I(2) = 89%] compared to placebo. Occurrence of treatment-emergent adverse events [Risk ratio (RR) 1.90 (95%CI: 0.52–6.91); P = 0.33; I(2) = 63%], serious adverse events [RR 1.40 (95%CI: 0.50–3.93); P = 0.53], constipation [RR4.11 (95%CI: 0.93–18.13); P = 0.06; I(2) = 0%], headache [RR0.48 (95%CI: 0.16–1.43); P = 0.19; I(2) = 0%], severe hypoglycemia [RR 0.87 (95%CI: 0.06 – 13.51); P = 0.92] were comparable across groups. Verapamil was well tolerated, and its use over one year was associated with significant improvements in C-peptide AUC though the HbA1c remained unchanged.