Penile length and circumference dimensions: A large study in young Italian men

Abstract The aim of the present study was to evaluate the size of the penis in flaccidity and in erection of Italian men. A total of 4,685 men living in Italy and who have been visited at the Italian urology operating units were involved in the study between January 2019 and January 2020. Each patient was given details on how to measure their penis (erect length and circumference) in flaccidity and in erection, from the lower base to the distal penile tip. Mean (standard deviation [SD]) flaccid penis length was 9.47 (2.69), mean (SD) flaccid penis circumference was 9.59 (3.08), mean (SD) erect penis length was 16.78 (2.55) and mean (SD) erect penis circumference was 12.03 (3.82). At the linear regression analysis, height was associated with flaccid penis length (β = 0.04; p‐value = .01), and erect penis length was (β = 0.05; p‐value < .01) and erect penis circumference was (β = 0.06; p‐value < .01). Height is proportional to the length of the penis in flaccidity and in erection, and to the circumference in erection. The increase in BMI leads to a reduction in the length of the erect penis, as well as weight gain reduces the length of the flaccid penis.


| MATERIAL S AND ME THODS
A total of 4,685 men from Italy and who have been visited at the Italian urology operating units were prospectively included in the study, which took place between January 2019 and January 2020 at the Careggi Hospital in Florence. We enrolled patients from the outpatient clinic during andrological consultation. Patients ≤ 15 years with erectile dysfunction, previous pelvic surgery, suspected hypogonadism, penile disease or deformity were excluded. Other exclusion criteria were applied as previously reported (Sanches et al., 2018). From each patient admitted to the study, basic information was collected: men completed demographic items (age, height, weight and height, habit of smoking, residence, and sexual orientation). Each patient was given detailed and illustrated directions on how to measure their penis (erect length and circumference) in flaccidity and in erection, from the lower base to the distal penile tip. Most men measured their penis while alone, using hand stimulation to become erect. All measurements were performed under similar environmental conditions (air-conditioned room and at temperatures varying from 23 to 25°C). Penile length was measured along the dorsum of the penis by a ruler with millimetre markings, with the patients standing up. The penile dimensions assessed were penile length from the pubo-penile skin vertex, depressing the pubic fat, to the extremity of the glans, with the ruler placed against the dorsal part of the penis and the circumference, the diameter at the midpoint of the penile shaft, in flaccidity and in erection (Suppl. Figure S1). All participants' ages were recorded.
Their height and weight were measured and recorded, and their BMI (ratio of weight in kilograms to height in meters squared) was calculated.
The study has been carried out in accordance with the Declaration of Helsinki for experiments involving humans and an informed consent has been signed from each patient.  were 416 (8.9%) and pansexual patients were 11 (0.2%). Mean (SD) flaccid penis length was 9.47 (2.69), mean (SD) flaccid penis circumference was 9.59 (3.08), mean (SD) erect penis length was 16.78 (2.55) and mean (SD) erect penis circumference was 12.03

| RE SULTS
(3.82). Tables 2-4 show baseline characteristics of North, Centre, South and Islands population. The mean of penis size stratified by geographic area did not reveal statistically significant differences, except for the length of the flaccid penis (p <.01) (Figure 1). The percentage distributions by geographical area are shown in the Supplementary Tables S1-S4 and divided into patients above and below the median with reference to penis size (Figures 2-3 We also demonstrated an association between BMI and flaccid penis circumference (β = 0.08; p-value < .01), and erect penis length was (β = −0.07; p-value < .01). Finally, weight was associated with flaccid penis length (β = −0.06; p-value < .01). and mean circumference of the erect penis was 12.23 cm (Herbenick et al., 2014). Another great study is that of Söylemez, a study con-  (Sengezer et al., 2002) and USA (9.01 ± 2.15 cm) (Wessells et al., 1996).

| D ISCUSS I ON
It is important to underline that associations between penile size and somatometric parameters papers still remain controversial. Results from a systematic review with up to 15,521 males in 20 studies showed that all somatometric correlations were either inconsistent or weak while the most reliable was the association flaccid stretched length and height .
Although all these premises, body acceptance and self-satisfaction Moreover, it is important to underlie different limitations for penile measurement.
In particular, temperature, level of arousal and previous ejaculation could also affect the penile dimensions. Using a disposable tape measure, a participant should have three parameters measured in the flaccid state: circumference (girth) of the penile, mid-shaft; length from suprapubic skin to distal glans (skin-totip); and pubis to distal glans (bone-to-tip) (Veale, Miles, Bramley, et al., 2015).
Before concluding, we should address some limitations. Firstly, measurements have not been conducted by the physician but this would have been unethical in an outpatient setting. In fact, performing the measurement during the visit would need the use of drug for the induction of erection or even self-made masturbation or during anaesthesia (Akyüz, 2020). Secondly, patients only measured the penis one time with possible error of measurement. Thirdly, we did not perform a comparison with other countries. Finally, we did not evaluate the impact of smoking duration and quantity with penile size.

| CON CLUS ION
Our study, therefore, showed that there are no statistically significant differences for penis size in Italy in the North, Central, South and Islands macro-areas, except for the length of the flaccid penis, which was greater in the North and lower in Central Italy. Our data showed that smoking patients are more likely to have a flaccid and erect penis circumference below average. In addition, we have shown that somatometrics characteristics matter. In particular, the height is proportional to the length of the penis in flaccidity and in erection, and to the circumference in erection. Furthermore, the increase in BMI leads to a reduction in the length of the erect penis, as well as weight gain reduces the length of the flaccid penis.

CO N FLI C T O F I NTE R E S T
None.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.