Insulin resistance impairs response to doxazosin therapy in men with benign prostatic hyperplasia

Aim: To evaluate the effects of insulin resistance (IR) on outcomes of doxazosin treatment for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).Materials and methods: This prospective study included 64 patients with LUTS due to BPH. LUTS were evaluated using the international prostate symptom score (IPSS) and maximum flow rate (Qmax) in uroflowmetry. Diagnosis of IR was achieved using homeostasis model assessment (HOMA) score and patients were grouped with respect to absence (group 1, n = 44) or presence (group 2, n = 20) of IR. Patients were evaluated before and after 3 months of daily doxazosin therapy (4 mg extended release tablet).Results: Doxazosin significantly improved the IPSS and Qmax in group 1 (P = 0.04 and P = 0.008, respectively). In group 2, doxazosin treatment had no significant therapeutic effect on mean IPSS and Qmax (P = 0.116 and P = 0.477, respectively). On the other hand, doxazosin significantly improved mean HOMA scores of patients with IR (P = 0.015).Conclusion: IR impairs response to doxazosin treatment for LUTS due to BPH. The presence of IR should be kept in mind in patients refractory to doxazosin therapy.