Effect of different alpha-receptor antagonists on metabolic parameters: a head-to-head comparison

Although it is known that alpha-adrenergic receptor antagonists have positive effects on metabolic parameters such as glucose metabolism, lipid profile, and insulin sensitivity, it is unclear whether this is a class effect. Tamsulosin is reported to have adverse effects on glucose metabolism and insulin resistance, and this may be because of its lack of glycolysis-enhancing effect compared with other alpha-adrenergic receptor antagonists with glycolysis-enhancing effects such as doxazosin, terazosin, and alfuzosin. The aim of this study was to compare the effect of tamsulosin on metabolic parameters with another alpha-1 adrenergic receptor antagonist, doxazosin.

In this prospective, observational, controlled, 12-week clinical study, a total of 60 male patients aged ≥ 40 years who were first started on tamsulosin (n = 30; 0.4 mg/day, oral; mean age, 59.20 ± 8.97 years) or doxazosin (n = 30; 4 or 8 mg/day, oral; mean age, 58.50 ± 8.93 years) for benign prostatic hyperplasia (BPH) or lower urinary tract symptoms (LUTS) were enrolled. The groups were compared according to the changes in anthropometric and biochemical parameters (glycemia, lipid profile, and insulin sensitivity) at the end of treatment.

In intragroup analyses, systolic blood pressure, diastolic blood pressure, total cholesterol, and HbA1c levels decreased significantly in the doxazosin group compared with baseline (p < 0.05 for all), while no significant change was observed in the tamsulosin group. In comparisons between groups, systolic blood pressure, total cholesterol, and low-density lipoprotein cholesterol levels showed a significant decrease in the doxazosin group compared with the tamsulosin group (percent change: - 6.68 ± 13.08 vs. 0.53 ± 11.02, p = 0.025; - 3.63 ± 9.56 vs. 4.02 ± 10.86, p = 0.005; and - 5.62 ± 18.18 vs. 5.24 ± 15.42, p = 0.015, respectively).

Although these results do not support previous findings that tamsulosin has adverse effects on metabolic parameters, they suggest that doxazosin treatment may be a reason for preference in patients with BPH or LUTS accompanied by metabolic disorder.