Objective: Abdominal obesity and type 2 diabetes mellitus are associated with erectile and urinary dysfunction in men. The extent to which sexual function and lower urinary tract symptoms (LUTSs) are improved by weight loss remains unclear.
Subjects: We compared the effects of 8 weeks of a low-calorie diet using meal replacements (Kicstart) on insulin sensitivity, plasma testosterone levels, erectile function (measured by the five-item version of the International Index of Erectile Function, IIEF-5), sexual desire (measured by the Sexual Desire Inventory, SDI) and LUTS (measured by the International Prostate Symptom Score, IPSS), in abdominally obese (body mass index >or=30 kg m(-2), waist circumference (WC) >or=102 cm) men (mean age 49.7 years) with uncomplicated diet or oral hypoglycemic-treated type 2 diabetes mellitus (n = 19) or without type 2 diabetes mellitus (n=25), with a control group of nondiabetic men (n = 26) with similar body mass index and WC.
Results: Weight loss of ∼ 10% was significantly associated with increased insulin sensitivity, plasma testosterone levels, IIEF-5 and SDI scores, as well as reduced WC and IPSS scores, in diabetic as well as nondiabetic men. The degree of weight loss was significantly associated with improvements in plasma testosterone levels (r = -0.34), erectile function (r = -0.26) and LUTS (r=0.65). Reduction in LUTS was significantly associated with increased plasma testosterone (r = -0.35), erectile function (r = -0.42) and sexual desire (r = -0.40).
Conclusions: Diet-induced weight loss significantly and rapidly improves sexual function, and reduces LUTS, in obese middle-aged men with or without diabetes.