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Effect of penile size on nocturnal erections: evaluation with NPTR testing with men having micropenis


There has been conflicting opinions in the literature regarding sexual function in hypogonadal men with micropenis. In this study we aimed to evaluate erectile function in hypogonadal men with micropenis by nocturnal penile tumescence and rigidity testing (NPTR) and compared the results with young potent normal penile sized men. A total of 15 men (ages 17–30 y) defined having a micropenis with a stretched penile length of less than 9.3 cm were constituted the study group. Mean stretched penile length was 6.8±1.6 cm (range 3.6–7.8 cm). Karyotype analysis showed 46XY in all cases. Control group included 22 potent and normal penile sized men (23–29 y). All subjects completed three sessions of consecutive nights using the RigiScan Plus device. Comparison of the results of NPTR of control group with study group revealed that number and duration of erectile episodes (P<0.001), duration of tip rigidity >60% (P<0.01), TAU tip and TAU base (P=0.001), and RAU base (P=0.01) were found to be significantly lower in men with micropenis. In conclusion, our study showed that men with micropenis are associated with decreased nocturnal erectile activity.

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Correspondence to O Yaman.

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Yaman, O., Soygür, T., Akand, M. et al. Effect of penile size on nocturnal erections: evaluation with NPTR testing with men having micropenis. Int J Impot Res 17, 243–247 (2005).

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  • micropenis
  • erectile function
  • NPTR testing


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