Evaluating the Impact of Penile Girth Discrepancy on Patient Bother in Men with Peyronie’s Disease: An Observational Study

Abstract

Background:

Men with Peyronie’s Disease (PD) may experience penile narrowing. Little data exists on penile girth changes and their psychosocial impact.

Aim:

To assess girth discrepancy in men with PD and its association with patient bother.

Methods:

This was a retrospective observational study. All PD patients at our institution who were seen in the sexual medicine clinic and who completed three validated instruments: the PD questionnaire (PDQ), Self-Esteem and Relationship (SEAR) questionnaire and a depression questionnaire, the Center for Epidemiologic Studies Depression Scale (CES-D) and a curvature assessment were included. Patient and PD characteristics are described. Associations of instability and bother to girth differences are assessed. Two outcomes for girth differences are classified as a) girth difference of ≥ 1cm versus less; and b) girth differences of ≥ 10% versus less. Unadjusted and adjusted effects of PD and patient characteristics are assessed on the outcome of high bother using logistic regression models.

Outcomes:

Penile girth changes, instability and questionnaire scores. High bother was defined as a PDQ bother score of ≥ 9.

Results:

131 men had midshaft curvature and were the focus of the study. Their mean age was 59±9 (range 31–78) years. PD duration was 16±25 (range 1–180) months, with a mean degree of primary curvature of 37±20°. Mean girth difference between base and point of maximum curvature was 0.78±0.53 cm equating to a mean girth difference at point of maximum curvature of 6±4%. Instability was present in 53% of men. There were 54 men with a girth difference of ≥ 1cm and 23 men with a ≥ 10% change in girth. There was no difference in CES-D, SEAR or PDQ domain scores or high bother in men with significant girth changes. Univariable analysis of predictors of high bother included the degree of curvature (OR 1.06; p<0.001), instability (OR 6.62; p<0.001), CES-D sum (OR 1.09; p=0.002) and SEAR score (OR 0.96; p=0.001). On multivariate analysis, only the degree of primary curvature was predictive of high bother (OR 1.06; p<0.001).

Clinical Implications:

Penile girth changes have little impact on overall psychosocial well-being. The degree of penile curvature is the primary predictor of patient bother.

Strengths and Limitations:

Strengths include a large patient population and use of validated questionnaires. Limitations include single-center, retrospective study and subjective instability grading.

Conclusions:

Penile girth discrepancy in men with PD has limited psychosocial impact. Clinically significant bother was associated with the degree of primary curvature.

INTRODUCTION

Peyronie’s Disease (PD) is a wound-healing disorder of the penis with formation of a fibrous plaque within the tunica albuginea, possible penile pain, and irregularity such as a penile curvature or hourglass deformity.¹ The prevalence varies in the literature between 2–8.9%, likely due to methods of diagnosis, from self-reporting to various definitions of clinical diagnosis.¹

PD is a frustrating condition and can lead to significant patient distress and depression. A series of 92 men with PD found that almost half of men screened positive for depression². There are numerous sources of such psychological distress, including uncertainty about progression of the disease, erectile dysfunction (ED), penile pain, the appearance of the penis and relationship conflict.²

Penile deformity associated with PD takes many forms, including curvature (uni or multiplanar), indentations, hourglass deformities (HGD), volume loss and penile tapering.^3–5 The latter involves discrepancies in penile girth along the penile shaft and is typically described as distal tapering. ⁵ While not well described in the literature, our clinical experience has noted 2 patterns of tapering in PD. This most commonly presents as either a ‘bottleneck’ deformity with the distal shaft narrower than the base or a ‘cobra head’ deformity with the base narrower than the distal shaft. While shaft tapering has been recognized to be associated with penile instability⁵, it has been our clinical experience that such tapering is directly associated with patient bother.

Little literature exists on penile girth changes and their impact on penile instability, sexual function and bother. Our clinical experience suggests that men with PD who experience loss of girth have more penile instability and bother related to their condition. The aim of this study was to describe girth changes in men with PD and to assess the prevalence of girth discrepancy in men with PD and its association with penile instability and patient bother. We hypothesized that men with girth changes would experience more penile instability and bother compared to men without these girth changes.

METHODS

Study Population:

This was a retrospective observational study approved by our Institutional Review Board. PD patients at our institution who were seen in the sexual medicine clinic from 2014–2019 and who completed validated questionnaires and a curvature assessment and duplex doppler ultrasound (CA/DUS) were included in this analysis. This study was approved by the Institutional Review Board (Protocol 16–405). Men were excluded if they did not complete the questionnaires or undergo a CA/DUS, or if they did not have girth data available. Patients’ PD diagnosis is based on the palpation of a tunical plaque by an experienced sexual medicine physician with > 20 years of PD experience. Comorbidities, demographic data and PD characteristics were recorded. We limited this analysis to men with mid-shaft curvature to prevent any confounding effects due to the location of the point of maximum curvature (PMC).

Questionnaire Assessments:

All patients completed three validated instruments: the PD questionnaire (PDQ), the Self-Esteem and Relationship (SEAR) questionnaire and a depression questionnaire, the Center for Epidemiologic Studies Depression Scale (CES-D). The CES-D is a 20-item questionnaire to screen for depression, with a higher score equating to more symptoms.⁶ The score ranges from 0–60, with a score ≥16 being consistent with depression. The Self-Esteem and Relationship (SEAR) questionnaire has 14 questions with domains of sexual relationship and confidence; the latter is split into sub-domains of overall relationship and self-esteem. A higher score indicates a more favorable response.⁷ The Peyronie’s Disease Questionnaire (PDQ) has 15 questions and 3 domains: psychological/physical symptoms, penile pain, and bother. These domains are scored separately and there is no sum score. A higher score indicates worse symptoms.⁸ Prior research has found that a PDQ bother domain score of 9 or greater is consistent with clinically significant bother.⁹ Thus, this was the definition used in the current study.

Girth Measurements:

Stretched flaccid length is obtained by measuring the penile length from pubic symphysis to coronal sulcus using a metal ruler while the penis is under manual stretch. PD patients have girth measurements and instability measured during their duplex Doppler ultrasound at the time of maximum erectile hardness. All patients undergo intracavernosal injection to induce an erection. The PMC is measured based on the physician’s perception while the penis is erect. Girth was measured by a physician using a disposable tape measure at the base of the shaft, the PMC, and distally just proximal to the glans. Instability was determined based on the significance of buckling with manual axial loading on the glans. If the penis buckled in the shaft with this axial loading, this was considered to be a demonstration of instability. The classification of mild, moderate or severe instability was based on subjective grading by the physician. Mild instability has minimal buckling, moderate was more significant but not to the effect that intercourse would be limited. Severe instability was defined as buckling significant enough to impair thrusting during intercourse.

Statistics:

The data were collected and entered into a database by physician fellows shortly after the patient encounters. The data were then reviewed retrospectively for this study. This analysis is limited to men with midshaft curvature. Demographic and comorbidity characteristics are described, girth and girth difference information is summarized, and associations of both instability and bother to girth differences are assessed. Missing data were handled with pairwise deletion so that power was maximized for each statistical test. Two outcomes for girth differences were analyzed: (i) girth difference of ≥1cm compared to < 1cm, and (ii) girth differences of ≥10% versus <10%. Unadjusted effects of physical characteristics, relationship duration, age, instability, and PD duration were assessed on the outcome of high bother (≥9 on the PDQ bother subscale) using logistic regression models. Statistically significant correlates were then included in an adjusted model. As this study was conducted retrospectively, power calculations were completed post hoc. An analytic sample of 131 men provides 80% power to detect a small-medium standardized effect size of at least Cohen’s w = 0.25 using a Chi-square test.

RESULTS

Study Population:

131 men had midshaft curvature and were the focus of the study. Their mean age was 59±9 (range 31–78) years. PD duration was 16±25 (range 1–180) months, with a mean degree of primary curvature of 37±20°. The majority of patients (87%) were partnered with a mean relationship duration of 286±168 months (range 1 month to 48 years). Few patients (2%) were current smokers, though nearly one quarter (23%) were former smokers. One quarter (25%) of patients were hypertensive, and over one third (38%) had high cholesterol. Few men (2%) had a history of angioplasty, none had angina, and one (1%) had a history of stroke. 8% were diabetic. Prevalence of depression was 12% and prevalence of anxiety was 7% among the cohort. 4% endorsed a history of penile trauma and one participant (1%) had Dupuytren’s contracture.

Girth and Instability Outcomes (Table 1):

Table 1:

Girth Changes (N = 131)

	Mean	SD
Stretched penile length (cm) (n = 130)	12.3	1.7
Degree of primary curvature (n = 129)	36.6	19.9
Girth at penile base (cm)	12.2	1.2
Girth at PMC* (cm)	11.4	1.2
Girth at distal penis (cm) (n = 66)	10.9	1.2
Girth base minus Girth PMC (cm)	0.78	0.53
Girth base minus Girth PMC)/ Girth base (ratio)	0.06	0.04

^*PMC= point of maximum curvature

Mean stretched penile length was 12.3±1.7 cm. The mean girth at the base of the penis was 12.2±1.2cm and the mean girth at the point of maximum curvature was 11.4±1.2cm. The mean distal girth was 10.9±1.2 cm. Mean girth difference between the base and the PMC was 0.78±0.53 (range 0–3) cm, with 54 men (41%) having a discrepancy between base and PMC of > 1cm. The mean girth difference percentage between base and PMC was 6±4%, with 23 (18%) with a ≥10% change in girth. Mean girth difference between distal and the PMC was 0.77±0.55 (range 0–2.5) cm, with 53 men (40%) having a discrepancy between distal and PMC girth of >1cm. The mean girth difference percentage between distal and PMC was 7±6%, with 23 (18%) with a ≥ 10% change in girth. Instability was present on exam in 53% of men. 58% of men with a girth difference of ≥ 1cm had instability compared to 44% men with a milder girth discrepancy (p=0.04). However, while 61% of men with ≥10% change in girth had instability compared to 49% men with <10% change, this was not statistically significant (p=0.18).

Questionnaire Scores:

There was no statistically significant difference in total CES-D or SEAR scores or PDQ domain scores in men with significant girth differences. For CESD, men with ≥ 1cm difference had a mean score of 11.6 versus 11.7 in men with < 1cm girth difference (p=0.92). For men with ≥ 10% change, the CES-D mean scores were 13.0 versus 11.4 in men with < 10% difference (p=0.44). Rates of depression were significantly different, however, between men with <10% difference in girth (27% met depression criteria) and men with ≥10% difference in girth (46% met depression criteria, p=0.024). Though not statistically significant (p=0.08), the same trend was exhibited where only 26% of men with <1 cm difference met CES-D depression criteria, compared to 38% of men with ≥ 1cm difference.

Total SEAR mean score was 51 in men with ≥ 1cm difference versus 59 in men < 1cm (p=0.08). There was also no difference in men with ≥ 10% difference (47.3 versus 57.4; p=0.10). In terms of SEAR sub-domain scores, men with ≥ 1 cm girth difference scored less favorably on the sexual relationship questions (40.8 ± 26.8 versus 52 ± 28; p = 0.04). Men with ≥ 10% girth changes scored less favorably on the self-esteem domain (54.4 ± 23.3 versus 67.6 ± 26.3; p=0.04). There was no difference between the groups in the other SEAR subscores.

For PDQ, the mean score for physical/psychological symptoms was 9.5 versus 7.8 (p=0.18) in men ≥ 1cm versus < 1cm difference. Similar results were seen for men with ≥ 10% versus < 10% difference: 9.4 versus 8.3; p=0.49. There was no statistically significant difference in mean pain scores: 5.2 versus 3.9; p=0.29 for men ≥ versus < 1cm difference and 3.9 versus 4.5; p=0.73 for ≥ versus < 10% difference. The bother domain was also similar with men ≥ 1cm versus < 1cm (6.3 versus 5.3; p=0.22) and men ≥ 10% versus < 10% (7.1 versus 5.4; p=0.16). There was no difference in clinically significant bother as defined as a PDQ bother sum of ≥ 9 in men with versus without a ≥ 1cm girth difference (p=0.82) or men with versus without a ≥ 10% change in girth (p=0.9).

Predictors of Bother:

Of 105 men with information on bother, around one quarter (24%) had clinically significant bother. Univariable analysis of predictors of clinically significant bother included the degree of primary curvature (OR 1.06; p<0.001), CES-D sum (OR 1.09; p<0.01) and total SEAR score (OR 0.96; p=0.001; Table 2). On multivariate analysis, only the degree of primary curvature was predictive of clinically significant bother (OR 1.06; p<0.01; Table 3).

Table 2:

Univariable Analysis^ǂ of Predictors of Clinically Significant Bother (defined as PDQ bother domain score ≥9) (N = 105)

	OR	95% CI	P-value
Age (years)	1.00	(0.95, 1.05)	0.98
Stretched penile length (cm)	0.87	(0.67, 1.14)	0.3
Degree of primary curvature	1.06	(1.03, 1.09)	<0.001
Girth Base (cm) (continuous)	1.12	(0.78, 1.60)	0.55
Girth PMC (cm) (continuous)	1.07	(0.73, 1.56)	0.73
Girth Distal (cm) (continuous)	1.16	(0.64, 2.08)	0.63
Girth Base –Girth PMC (cm) (continuous)	1.32	(0.57, 3.09)	0.52
Girth Base –Girth PMC (cm) (categorical)
< 0.5cm	REF		0.45
0.5–1.0cm	1.75	(0.63, 4.93)
>1cm	1.98	(0.58, 6.74)
Girth base - Girth PMC/Girth base (continuous) *	1.47	(0.50, 4.34)	0.49
Girth base - Girth PMC/Girth base (categorical)
<2%	0.38	(0.06, 2.40)	0.57
2–4.9%	0.96	(0.23, 3.93)
5–9.9%	1.20	(0.32, 4.47)
≥ 10%	REF
Instability
Instability none	REF
Instability mild	0.95	(0.31, 2.95)	0.002
Instability moderate	4.49	(1.69, 11.93)
Instability severe	4.77	(0.75, 30.42)
PD duration (months)	1.00	(0.99, 1.02)	0.82
Relationship duration (years)	1.00	(1.00, 1.00)	0.31
CES-D Sum	1.09	(1.03, 1.15)	0.002
SEAR Sum	0.96	(0.94, 0.98)	0.001

^ǂLogistic regression models were used to regress bother separately on each variable.

^*Note: Modeled per 10-point increase

Table 3:

Multivariate Analysis^ǂ of Predictors of Clinically Significant Bother (defined as PDQ bother domain score ≥9) (N = 85)

	OR	CI	P-value
Degree of primary curvature	1.06	(1.01, 1.10)	0.001
Instability –categorical
Instability none	REF		0.25
Instability mild	2.71	(0.47, 15.71)
Instability moderate	3.54	(0.79, 15.78)
Instability severe	8.22	(0.55, 122.91)
CES-D Sum	1.06	(0.98, 1.14)	0.14
SEAR Sum	0.97	(0.94, 1.00)	0.07

^ǂA single Logistic regression model was used to simultaneously assess the associations of each predictor to bother.

DISCUSSION

The prevalence of PD varies in the literature based on the definition used and the patient population studied. The AUA guidelines note a broad range of 0.5–20.3%.¹⁰ Using the definition of a self-diagnosed penile plaque, a study of about 4,400 men from Germany found an overall PD rate of 3.2%. This increased with age from 1.5% of men in their 30’s to 6.5% in men ≥ 70 years old.¹¹ An online survey of 1,782 Australian men asked about the presence of a penile bend or curvature, and 19% of respondents endorsed these symptoms.¹² A similar study performed in the US used online surveys of adult men to determine the prevalence of definitive PD (defined as symptoms and a known diagnosis of PD) and probable PD (defined as symptoms of PD without a definitive diagnosis by a physician). The prevalence of definitive PD was only 0.7% but 11% of men had probable PD.¹³ Another study evaluated 534 men who presented for prostate cancer screening but who had no genitourinary complaints. PD was defined as a palpable plaque noted by a clinician during the physical exam. Using this criteria, PD was in 8.9% of these men.¹⁴ This demonstrates not only the significant amount of men with PD symptoms, but also the low percentage of men who seek care and obtain a formal diagnosis.

PD is known to have significant psychosocial impact in men². In the Australian study mentioned previously, 26% of the men with penile curvature were bothered by the appearance of their penis, and 20% were bothered when attempting intercourse. 16% of men noted a decline in confidence and 10% experienced a negative impact on their self-esteem.¹² During the initial phases of development for the PDQ, focus groups of a total of 28 men with PD were conducted. They found that bother was ‘universally high’ in these men. All men with PD experienced some degree of negative changes to their sexual image and almost all of them endorsed social stigmatization because of their disease. Interestingly, a loss of girth or length affected men psychosocially just as much as severe disfigurement.¹⁵ In the aforementioned study that discovered high depression rates in men with PD, they found that predictors of depression in these patients included being single and experiencing penile shortening (p<0.05 for both).²

Another study of 245 men with PD evaluated its association with emotional and relationship problems.¹⁶ These men were asked yes/no whether they were having emotional or relationship problems from PD. 81% of men reported emotional problems. Predictors included relationship problems (p<0.001) and loss of penile length (p=0.02). Relationship problems were acknowledged by 54% of men and were predicted by emotional problems (p<0.001) and the inability to have intercourse (p=0.004).¹⁶ This echoes the notion that loss of length leads to an increased psychosocial impact in men with PD.

With regards to penile volume loss associated with PD, a study of 128 men was conducted evaluating instability and volume loss.⁵ Patients completed the men’s sexual health questionnaire (MSHQ) which evaluated impairment and distress associated with PD and associated penile volume loss. Instability was determined by buckling of the penis with axial pressure during the physical exam. Of the 128 men, 83 (65%) had volume loss with 39% having an indent, 23% an hourglass deformity and 13% with distal tapering.⁵ Even after controlling for penile curvature, men with volume loss deformities had more penile instability (OR 3.5, p=0.01), decreased sexual activity (OR 2.7, p=0.02), and experienced more distress (OR 2.6, p=0.03). There was no difference in penile pain, libido, erectile or ejaculatory dysfunction or sexual dissatisfaction in men with volume loss deformities.⁵ This demonstrates the significant impact that girth changes can have in men with PD.

We anticipated that significant girth changes would have a psychosocial impact on men with PD. However, our study did not clearly demonstrate that worsening girth changes had an increased psychosocial impact on these men with CES-D, SEAR sum and PDQ domain scores being similar in men with and without significant girth changes. While significant bother was the same in men despite girth differences, there were higher depression rates in men with ≥10% girth difference compared to less. Penile curvature, categorical girth discrepancy and the presence of instability were predictors of bother on univariable analysis, but only penile curvature remained a significant predictor on multivariable analysis. This implies that curvature is the most bothersome aspect of PD, as the degree of curvature has more of a psychosocial impact than even significant girth changes.

There is limited data on the impact of girth changes in men with PD and the psychosocial impact. However, in the previously mentioned volume loss study using the MSHQ, men with girth changes had decreased sexual activity and experienced more distress.⁵ We believe that our more thorough evaluation using 3 validated questionnaires (CES-D, PDQ, and SEAR) may explain the difference in these findings.

Strengths of this study include the use of prospectively collected data and a large patient population of men with PD. We utilized validated questionnaires to ascertain the psychosocial impact of men with PD. Additionally, we systematically analyzed girth on exam at the time of duplex Doppler ultrasound. To our knowledge, this is one of the first studies specifically analyzing the psychosocial impact of girth changes in men with PD and it is the largest study to do so. Limitations include the retrospective nature which could introduce recall bias. Additionally, we evaluated instability in a subjective manner based on manual axial loading by the examiner and not using a rigidometer. While this is not objective, this technique has been published previously as a legitimate means of measuring penile instability.⁵ Lastly, our sample size of 131 men with mid-shaft curvature is a relatively small patient population. This study is powered for medium effect size only and may have missed subtle effects. The psychosocial impact of girth changes may become statistically significant with large sample sizes.

Clinical implications of this study are numerous. To our surprise, and counter to our clinical experience, we have shown that while a girth difference of ≥ 1cm is associated with worsening penile instability, there is no impact of girth changes on overall psychosocial function as measured by sum CES-D and SEAR scores or PDQ domain scores. It is possible that with greater patient numbers we would see somewhat different results, although the patient population was sizeable. Multivariable analysis of significant bother demonstrated that only the degree of primary curvature was predictive of bother. This is important for patient counseling and treatment.

CONCLUSION

Significant girth discrepancy in men with PD had limited psychosocial impact in terms of SEAR, PDQ, and CES-D scores. Men with significant girth changes did not have higher rates of clinically significant bother compared to men with less severe girth discrepancy, although men with ≥10% girth differences were more likely to screen positive for depression. On MVA, only the degree of primary curvature was predictive of clinically significant bother in men with PD.