Clinical, anthropometric, metabolic and insulin profile of men with fast annual growth rates of benign prostatic hyperplasia

The purpose of this study was to test the hypothesis of a causal relationsh ip between high insulin levels and the development of benign prostatic hype rplasia (BPH) and to determine the clinical, anthropometric, metabolic and insulin profile in men with fast-growing BPH compared with men with slow-gr owing BPH, The present study was designed as a risk factor analysis of BPH in which the estimated annual BPH growth rate was related to components of the metabolic syndrome. Two hundred and fifty patients referred to the Urol ogical Section, Department of Surgery, Central Hospital, Varberg, Sweden, w ith lower urinary tract symptoms with or without manifestations of the meta bolic syndrome were consecutively included. The prevalences of atherosclero tic disease manifestations, non-insulin-dependent diabetes mellitus (NIDDM) and treated hypertension were obtained. Data on blood pressure, waist and hip measurement, body height and weight were collected and body mass index (BMI) and waist/hip ratio (WHR) were calculated. Blood samples were drawn f rom fasting patients to determine insulin, total cholesterol, triglycerides , HDL and LDL cholesterol, uric acid, alanine aminotransferase (ALAT) and p rostate-specific antigen (PSA), The prostate gland volume was determined us ing ultrasound. The median annual BPH growth rate was 1.04 ml/year. Men with fast-growing B PH had a higher prevalence of NIDDM (p = 0.023) and treated hypertension (p = 0.049). These patients were also taller (p = 0.004) and more obese as me asured by body weight (p < 0.001), BM1 (p = 0.026), waist measurement (p < 0.001), hip measurement (p = 0.006) and WHR (p = 0.029). Moreover, they had elevated fasting plasma insulin levels (p = 0.018) and lower HDL cholester ol levels (p = 0.021) than men with slow-growing BPH. The annual BPH growth rate correlated positively with diastolic blood pressure (rs = 0.14; p = 0 .009), BMI (rs = 0.24; p < 0.001) and four other expressions of obesity and fasting plasma insulin level (rs = 0.18; p = 0.008), and negatively with t he HDL cholesterol level (rs = -0.22; p = 0.001). In conclusion, the data suggest that NIDDM, hypertension, tallness, obesity , high insulin and low HDL cholesterol levels constitute risk factors for t he development of BPH. The results also suggest that BPH is a component of the metabolic syndrome and that BPH patients may share the same metabolic a bnormality of a defective insulin-mediated glucose uptake and secondary hyp erinsulinaemia, as patients with the metabolic syndrome. The findings suppo rt the hypothesis of a causal relationship between high insulin levels and the development of BPH, and give rise to a hypothesis of increased sympathe tic nerve activity in men with BPH.