Serum l-carnitine and vitamin D levels may be low among oral sildenafil citrate non-responders

• Published in: International journal of impotence research 2019-03, Vol.31 (2), p.85-91
• Main Authors: Mostafa, Taymour, Rashed, Laila A., Sabry, Dina A., Osman, Ihab, Nabil, Nashaat, Kareem, Firas, Mostafa, Ingi A.
• Format: Article
• Language: English
• Subjects: 25-Hydroxyvitamin D 2 - blood; 692/499; 692/53; Administration, Oral; Adult; Amino acids; Cancer surgery; Carnitine - blood; Case-Control Studies; Cross-Sectional Studies; Effectiveness; Egypt; Erectile dysfunction; Erectile Dysfunction - blood; Erectile Dysfunction - drug therapy; Humans; Inhibitor drugs; Male; Medicine; Medicine & Public Health; Mens health; Metabolites; Middle Aged; Phosphodiesterase Inhibitors - therapeutic use; Prostate cancer; Reproductive Medicine; Reproductive system; rology; Sexual disorders; Sildenafil Citrate - therapeutic use; Surveys and Questionnaires; Urology; Vitamin D
• ISSN: 0955-9930; 1476-5489
• DOI: 10.1038/s41443-018-0036-4

This cross-sectional comparative study aimed to compare serum l -carnitine and 25(OH)D levels between men with ED non-responding for oral sildenafil citrate and healthy volunteers. Overall, 192 men, recruited from two University Hospitals, were allocated into two equal groups of matched age; healthy potent men and men with ED non-responders for oral sildenafil citrate. Oral sildenafil citrate non-responders self-reported inadequate erectile responses after four attempts using 100 mg with the manufacturer’s guidelines relative to meals, associated medications, and sexual stimulation/arousal. Exclusion criteria were: diabetes, cardiovascular disorders, beta blockers treatment, morbid obesity, thyroid disorders, post-radical prostatectomy, and hepatic/renal failure. All participants were subjected to; history taking, clinical examination, validated IIEF-5 questionnaire, estimation of serum l -carnitine by calorimetric method and serum 25(OH)D by ELISA method. Compared with potent controls, ED men non-responders for oral sildenafil citrate showed significant decreases in the mean serum l -carnitine level (16.8 ± 3.6 uM/L versus 66.3 ± 11.9 uM/L, P  = 0.001), the mean serum 25(OH)D level (21.2 ± 7.1 ng/ml versus 54.6 ± 7.9 ng/mL, P  = 0.001) and IIEF-5 score (7.8 ± 2.6 versus 23.9 ± 1.3). Serum l -carnitine showed significant positive correlation with IIEF-5 scores ( r  = 0.873, P  = 001), serum 25(OH)D ( r  = 0.796, P  = 0.001) and significant negative correlation with the age ( r  = -0.515, P  = 0.001). Serum 25(OH)D showed significant positive correlation with IIEF-5 scores ( r  = 0.855, P  = 0.001) and significant negative correlation with the age ( r  = -0.223, P  = 0.005). It is concluded that normal homeostasis of serum l -carnitine and 25(OH)D play a role in male sexual health being significantly decreased in ED non-responding for oral sildenafil citrate.