In addition to previously reported risk factors, patient’s subjective impressions of penile size negatively impacts sexual life in about 10% of men considered healthy, while objective penile length does not play significant role in erectile function

Does underestimated penile size impact erectile function in healthy men? Brunno CF Sanches et al. International Journal of Impotence Research, volume 30, pages158–162 (2018). https://www.nature.com/articles/s41443-018-0039-1

Abstract: The aim of this study is to assess the impact of objective (stretched) and subjective penile size in the erectile function in a urological check-up program on a cross-sectional study including 689 men aged 35–70 years. IIEF-5 questionnaire, physical examination (penile length, prostate volume, blood pressure, body mass index-BMI), metabolic syndrome (MS), comorbidities, habits (sexual intercourse frequency, physical activity, alcohol, and tobacco use), level of education, serum glucose, total testosterone, estradiol, PSA, lipid profile, and self-perceptions (ejaculation time and subjective penile size) were examined in multivariate models using logistic and linear regressions. Penile objective mean length was 13.08 cm ± 2.32 and 67 (9.72%) patients referred small penis self-perception. Seventy-six (11.03%) participants had severe erectile dysfunction (ED), 75 (10.88%) had mild to moderate and moderate ED, 112 (16.25%) had mild ED and 426 (61.83%) had no ED. Risk factors for ED that held statistical significance were self-perceived small penis (OR = 2.23, 95% CI 1.35–3.69, p = .0017), sexual intercourse frequency (per week) (OR = 0.45, 95% CI 0.38–0.52, p < .0001), satisfactory ejaculation time (no vs. yes, OR = 2.06, 95% CI 1.46–2.92, p < .0001), comorbidity (yes vs. no, OR = 2.01, 95% CI 1.46–2.76, p < .0001), age >65 years (OR = 2.93, 95% CI 1.53–5.61, p < .0001), tobacco use (yes vs. no, OR = 1.41, 95% CI 1.02–1.96, p < .0375), regular physical activity (no vs. yes, OR = 1.59, 95% CI 1.13–2.23, p < .0083), serum total testosterone < 200 ng/dl (OR = 3.48, 95% CI 1.69–7.16, p = 0.0009), serum glucose > 100 mg/dl (OR = 1.69, 95% CI 1.18–2.43, p = 0.0044) and systolic blood pressure > 130 mmHg (OR = 1.60, 95% CI 1.16–2.19, p = 0.0037). Results suggest that in addition to previously reported risk factors, patient’s subjective impressions of penile size negatively impacts sexual life in about 10% of men considered healthy, while objective penile length does not play significant role in erectile function.