Glutathione levels in patients with erectile dysfunction, with or without diabetes mellitus

Abstract

The reduced form of glutathione (GSH) is the most important cell antioxidant and is also an essential cofactor for nitric oxide (NO) synthase that synthesizes NO from l-arginine. Reduced levels of GSH, due both to a hyperglycaemia-induced increase of free radical production and to a decrease of NADPH levels [like in diabetes mellitus (DM)], can hamper the endothelial cell functions. This condition may play an important role in the aetiology of some clinical signs, like erectile dysfunction (ED). The aim of this study was to test the hypothesis that GSH concentration is reduced in patients with ED and type 2 diabetes mellitus. We studied 111 male patients with ED: 64 with diabetes (ED/DM) and 47 without diabetes (ED/wDM); 20 patients with diabetes but without ED (DM) and 26 male normal subjects as a control group (C). The GSH red blood cell concentration was significantly lower in ED than in C (X +/- SD; 1782.12 +/- 518.02 vs. 2269.20 +/- 231.56 mumol/L, p < 0.001). In particular, GSH was significantly reduced in ED/DM vs. ED/wDM (1670.74 +/- 437.68 vs. 1930.63 +/- 581.01 micromol/L, p < 0.01). In DM, GSH was significantly lower than in C and significantly higher than in ED/DM (2084.20 +/- 118.14 vs. 2269.20 +/- 231.56 and vs. 1670.74 +/- 437.68 micromol/L, p < 0.002 and p < 0.001 respectively). GSH showed a negative correlation with fasting glucose concentrations (r = -0.34, p < 0.01) and with the duration of DM (r = -0.25, p < 0.05). A GSH depletion can lead to a reduction of NO synthesis, thus impairing vasodilation in the corpora cavernosa.

A multifaceted approach to maximize erectile function and vascular health

“…Fertil Steril 2010. men with ED have a lower intake of dietary antioxidants that keep glutathione in the reduced state. The lower levels of GSH in diabetics and the negative correlation found with blood glucose (14) suggest that obesity, diabetes, and increased dietary sugar reduce NO production through the vascular oxidative stress caused by increased circulating glucose.…”

“…2) (14). Note the narrow standard errors of these observations indicating the consistent levels among individuals.…”

“…The level (mean AE SE) of red blood cell reduced glutathione in men with ED was significantly lower (P< .001) compared with men without ED (14). Meldrum.…”

Lifestyle and metabolic approaches to maximizing erectile and vascular health

“…Adapted with permission. 2 Lifestyle, metabolism and erectile function DR Meldrum et al production that lasted for a week. 27 Moderate exercise may be preferable to extreme exercise.…”

“…(mmol l À1 ), respectively, both Po0.001); diabetic men, as expected, had significantly lower levels than men without diabetes ( Figure 1). 2 In a study of young men with ED, serum levels of paraoxonase-1 activity were markedly lower (mean ± s.d. 119 ± 62 versus 185 ± 56, Po0.001) compared with men without ED.…”