Insulin Resistance Is an Independent Predictor of Severe Lower Urinary Tract Symptoms and of Erectile Dysfunction: Results from a Cross-Sectional Study

Abstract

Introduction Several studies have linked the association between lower urinary tract symptoms (LUTS), erectile dysfunction (ED), and the presence of insulin resistance (IR) due to an underlined metabolic syndrome (MetS). Aim This study aims to determine the relationship between IR, sexual function, and LUTS and to demonstrate the ability of IR in predicting ED and severe LUTS. Methods Between January 2008 to January 2013, 544 consecutive patients with benign prostatic hyperplasia-related LUTS were enrolled. LUTS and sexual function of the patients were evaluated by the International Index of Erectile Function (IIEF) and the International Prostate Symptom Score (IPSS). MetS was defined by the International Diabetes Federation. IR was defined as a homeostasis model assessment (HOMA) index of 3 or greater. Main Outcome Measures Uni- and multivariate logistic regression analysis was performed to assess significant predictors of severe LUTS (IPSS ≥20) and ED (IIEF-Erectile Function [IIEF-EF] <26), including MetS component, prostate volume, prostate-specific antigen, total testosterone, and HOMA index. Results IR patients resulted in higher values of IPSS (19.0 vs. 15.0; P < 0.01), IPSS-storage (6.0 vs. 5.0; P < 0.01), IPSS-voiding (12.0 vs. 9.0; P < 0.01), total prostate volume (54.8 vs. 36.5; P < 0.01), and lower values of IIEF-EF (17.0 vs. 20.0; P < 0.01), IIEF-Intercourse Satisfaction (3.0 vs. 10.0; P < 0.01), IIEF-Orgasmic Function (8.0 vs. 9.0; P < 0.01), IIEF-Overall Satisfaction (6.0 vs. 8.0; P < 0.01), and total testosterone (3.83 vs. 4.44; P < 0.01). IR was demonstrated to be a strong predictor of ED (IIEF-EF <26) (odds ratio [OR] = 6.20, P < 0.01) after adjusting for confounding factors. Finally, IR was also an independent predictor of severe LUTS (IPSS ≥20) (OR = 2.0, P < 0.01) after adjusting for confounding factors. Conclusions IR patients are at high risk of having severe LUTS and contemporary sexual dysfunctions. We strongly suggest to prevent LUTS and ED by reducing insulin resistance.

Treatment With Metformin Improves Erectile Dysfunction in a Murine Model of Obesity Associated With Insulin Resistance

“…[2][3][4][5] Evidence supports a strong causal link between IR and ED. [6][7][8][9][10] In fact, ED has been considered an early clinical manifestation of risk factors for cardiovascular events including acute myocardial infarction. 11 In addition, ED may be the first clinical sign of IR in young men.…”

Increase of Framingham cardiovascular disease risk score is associated with severity of lower urinary tract symptoms

“…We have also recently shown that serum insulin increases were associated with greater severity of LUTS-BPH and ED [15]. It is plausible that insulin levels determine a lower synthesis and release of NO, owing to lower activity and expression of NO synthase, which is combined with an accelerated consumption of NO [16].…”

“…LUTS were evaluated by culturally and linguistically validated versions of the IPSS. LUTS severities were classified as mild (IPSS 0-7), moderate (IPSS [8][9][10][11][12][13][14][15][16][17][18][19] and severe . The short form of the International Index of Erectile Function (IIEF) questionnaire was used for the assessment of patients' erectile function and the presence of ED was considered to be IIEF-erectile function <26 [14].…”

Predicting erectile dysfunction in sexually active patients seeking prostate health screening: proposal for a multivariable risk stratification

“…16,17 The aim of this study was to verify whether ED, as objectively defined by the International Index of Erectile Function (IIEF-5), is associated with increase of comorbidities, calculated with the Charlson comorbidity index (CCI) and LUTS, defined by the IPSS.…”