Materials and methods
This was a hospital-based study investigating the prevalence and predictors of AD in men with LUTS in a medical center in Taiwan. We found that the prevalence of AD was estimated to be 55.7% in men with LUTS in our Urology Outpatient Clinic. There was a considerable portion of patients both with LUTS and AD that had hyperlipidemia, pre-DM, coronary artery disease, and lxr agonists (23.5%, 48.5%, 4.4%, and 46.3%, respectively). Although there was no statistical difference in the prevalence of these associated factors compared with those of the non-AD group, we still need to pay attention to these baseline conditions to identify potential AD patients. As for the other parameters, elevated WBC and WC were significantly associated with AD and increased body weight was borderline associated with AD in the univariate analysis. In the multivariate analysis, however, only men with LUTS with elevated WC revealed a significantly higher risk for AD, and elderly men with LUTS showed a borderline risk for AD. Men with LUTS and WC > 90 cm had a 2.86-fold higher risk for AD than those who had WC < 90 cm. Given that some previous studies found a positive association between metabolic syndrome and LUTS, while other studies reported conflicting data, we only analyzed the parameters in metabolic syndrome (including hyperglycemia, hypertension, triglycerides, high density lipoprotein-C, WC) separately and determined that WC can be seen as an indicator of AD in men with LUTS in Taiwan. Although previous studies have investigated the relationship between AD and LUTS, no consistent correlations were found. In the Third National Health and Nutrition Examination Survey, Rohrmann et al evaluated the association of circulating sex steroid hormone with LUTS. No consistent associations were observed between circulating and free testosterone and risk of LUTS. In Kim et al\’s investigation of the relationship between nocturia and decreased serum testosterone in men with LUTS in Korea, decreased testosterone was a significant independent risk for overall nocturia, especially nocturnal polyuria, and patients with low serum testosterone showed increased nocturnal urine output. Yassin and colleagues proposed the potential role of testosterone in the urinary tract in that testosterone may interact with LUTS via several possible mechanisms, such as by acting on nonpost synaptic receptors in the bladder detrusor muscle and by stimulating nitric oxide production in the urinary tract and bladder. Despite the inconsistencies so far observed in the relationship between AD and LUTS, replacement with testosterone for men with late-onset hypogonadism (LOH) improves LUTS. Testosterone therapy improves LUTS/bladder function by increasing bladder capacity and compliance, and decreasing detrusor pressure in men with LOH. One 5-year prospective, observational study also demonstrated that testosterone replacement is associated with improvements in LUTS and International Prostate Symptom Score in men with LOH. These studies indicate the importance of identifying AD in men with LUTS, with early detection and replacement of testosterone for AD being able to improve the life quality in men with LUTS.
In our study, increased WC rather than body mass index is an independent indicator of AD and in men with LUTS. One epidemiological investigation by Svartberg et al enrolled 1548 men aged 25–84 years surveyed the correlation between sex steroid hormones and central obesity. They found that all hormone associations were stronger for WC than for body mass index and suggested that WC should be the preferred anthropometric measurement in predicting endogenous testosterone levels. Measuring WC is a simple way to predict intra-abdominal fat volume or area and where it is placed around the body and increased intra-abdominal fat is associated with an increase in insulin resistance and systemic inflammation, which may contribute to low testosterone levels. In addition, total and free testosterone levels have been observed to decrease with increasing age in longitudinal studies, and thus it is not surprising in our study that older age was associated with a borderline rise in the risk of AD.
Materials and methods