Comparing effects of weight loss on sexual, urinary and endothelial function, insulin resistance and quality of life in obese men with and without erectile dysfunction

J. Khoo; R. Chen; L. Cho; T. Tay; E. Tan; V. Au; S. Soh; B. Ng

Introduction: Abdominal obesity and insulin resistance are risk factors for erectile dysfunction (ED). ED is associated with hypoandrogenism, endothelial dysfunction, lower urinary tract symptoms (LUTS), and reduced quality of life (QoL). We aimed to compare effects of lifestyle modification-induced weight loss on insulin resistance, endothelial and sexual function, LUTS and QoL in obese non-diabetic men with and without ED.

Methods: Seventy abdominally obese Asian (body mass index ≥30 kg/m², waist circumference (WC) ≥90 cm) men (mean age 43.1 years, range 30–61) were tested with International Index of Erectile Function 5-item (IIEF-5) questionnaire. 68.5% (n=48) had ED (IIEF ≥21). Weight loss was induced using caloric restriction (500 kcal/day below basal metabolic rate) and moderate-intensity exercise (2000 kcal/week). IIEF-5, Sexual Desire Inventory (SDI), International Prostate Symptom (IPSS) and 36-item Short Form Survey Instrument (SF-36) scores, plasma sex-hormone binding globulin (SHBG), total testosterone (TT), insulin and glucose, endothelial function (by reactive hyperaemia index (RHI) using finger plethysmography on EndoPAT), were measured at baseline and 12 weeks later. Homeostasis model assessment (HOMA) was used to estimate insulin resistance.

Results: At baseline, men with ED had lower IIEF-5 and SDI scores, TT, SHBG and calculated free testosterone (FT), and higher WC, HOMA, and IPSS score. Men with ED had significantly greater increases in IIEF-5 (2.83 vs 0.05), SDI (8.27 vs 2.45) scores and decrease in IPSS score (1.90 vs 0.82) and HOMA (2.03 vs 0.65). Improvements in weight, WC, RHI, TT, SHBG, and SF-36 scores were similar (Table 1). IIEF-5 score normalized in 12 (25%) men.

Conclusions: Weight loss through diet and exercise in obese men reverses ED and improves sexual desire, endothelial function, LUTS, insulin resistance and quality of life, producing significantly greater benefits on insulin resistance, sexual and urinary function in men with ED.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.

**Table 1** Changes in anthropometry, sexual function, sex hormones, LUTS, sexual and endothelial function and LUTS after 12 weeks of lifestyle modifcation.
	ED (n=48) Mean±S.D.	No ED (n=22) Mean ±S.D.	P value
Baseline age (years)	44.3±8.5	40.5±7.4	0.07
Baseline BMI (kg/m²)	32.5±3.5	31.7±3.4	0.12
Baseline weight (kg)	96.9±10.6	94.2±10.8	0.32
Baseline WC (cm)	106.9±7.1	101.6±6.6	0.004
Baseline IIEF-5	15.9±4.6	23.7±1.2	<0.001
Baseline SDI	47.2±20.0	57.2±16.2	0.03
Baseline IPSS	6.1±4.2	2.6±2.3	0.001
Baseline TT (nmol/l)	12.26±3.97	12.71±4.74	0.68
Baseline SHBG (nmol/L)	25.88±9.01	24.58±10.12	0.59
Baseline FT (pmol/l)	287±97	298±87	0.67
Baseline RHI	1.89±0.56	1.92±0.61	0.83
Baseline HOMA	6.55±4.34	4.51±2.29	0.01
Baseline SF-36 (physical component)	45.3±7.8	49.6±6.4	0.02
Baseline SF-36 (mental component)	49.0±7.9	49.2±8.0	0.94
Δweight (kg)	-4.1±3.4	-3.4±2.1	0.32
Δ WC (cm)	-3.7±3.1	-3.3±2.1	0.62
Δ IIEF-5	2.8±2.5	0.1±1.6	<0.001
Δ SDI	8.3±10.3	2.5±9.1	0.02
Δ IPSS	-1.9±2.7	-0.8±1.6	0.04
Δ TT (nmol/l)	1.66±2.70	1.43±2.43	0.73
Δ SHBG (nmol/l)	2.58±4.36	2.43±3.22	0.88
Δ FT (pmol/l)	27±58	26±61	0.94
Δ RHI	0.36±0.50	0.41±0.63	0.70
Δ HOMA	-2.03±2.88	-0.65±1.19	0.01
Δ SF-36 (physical component)	5.1±6.6	3.2±4.9	0.24
Δ SF-36 (mental component)	3.7±4.8	5.2±6.8	0.35

Endocrine Abstracts

P1023