The association of calcium channel blockers with beta-cell function in type 2 diabetic patients: A cross-sectional study

Type 2 diabetes mellitus (T2DM) patients are often accompanied with hypertension. However, the association of antihypertensive drugs with beta-cell function has not been well studied. To investigate this question, the authors performed a cross-sectional study involving 882 hypertensive T2DM patients. To assess beta-cell function, patients were given 75g glucose orally and C-peptide levels before and 1, 2, and 3 hours after glucose intake were measured. Homa-beta was computed by Homeostasis Model Assessment model to evaluate beta-cell function using fasting C-peptide and glucose levels in the plasma. Multivariable-adjusted analysis was performed to evaluate the association of antihypertensive drugs with C-peptide levels, HbA1c, and Homa-beta. Among 882 hypertensive patients, 547 (62.0%) received antihypertensive treatment. Multivariate-adjusted analysis demonstrated that use of calcium channel blockers (CCBs) was negatively associated with HbA1c levels (CCBs: 0.95 [95% CI: 0.92-0.98], P = 0.002). Our data further illustrated that the C-peptide levels before and 1, 2, and 3 hours of OGTT were 1.10-, 1.18-, 1.19-, and 1.15-fold increase in T2DM patients taking CCBs (P = 0.084 for fasting C-peptide levels; P = 0.11). In conclusion, CCB treatment was negatively associated with HbA1c levels but positively associated with beta-cell function in hypertensive T2DM patients, implying that CCBs could be considered to treat hypertensive T2DM patients with reduced beta-cell function.