Premature ejaculation and serum leptin level: a diagnostic case-control study

Diagnostic work up: Laboratory and biomarkers

This chapter will focus on the diagnostic work around sexual dysfunction in Parkinson's disease, especially laboratory tests and biomarkers. A number of methods to analyze if sexual dysfunction is caused by neural pathology, vascular dysfunction or other mechanisms are now available. Other methods can be used to differentiate between psychogenic/functional reasons behind sexual dysfunction and organic ones. The role of biomarkers for diagnosis, but also for understanding the reason behind and for counteracting sexual dysfunction is becoming more evident. There is also a rich and increasing number of scales and other instruments available for detecting and quantifying sexual hypo- and hyperactivity. When investigating the reason behind sexual dysfunction in patients with Parkinson's disease comorbidities should also be considered. Finally, early and pronounced sexual dysfunction might in some cases be an indication that differential diagnosis, like Multisystem Atrophy, should be thought about. All these aspects of the diagnostic procedures around sexual dysfunction in Parkinson's disease will be covered in this chapter.

Premature ejaculation: an update on definition and pathophysiology

Premature ejaculation (PE) is the most common male sexual dysfunction, which represents a diagnostic as well as a therapeutic challenge for physicians. However, no universally accepted definition is currently available for PE. As a result, physicians continue to diagnose patients with PE according to major guidelines set by the professional societies. These guidelines either recommend the use of validated questionnaires or patient-reported outcomes. Recent efforts directed toward classifying PE may help provide a better understanding of the prevalence and risk factors of this disorder. While the exact etiology of PE has not been clearly elucidated, several risk factors have been strongly reported in the literature. Clearly, to understand the revised definition of PE, its etiology and pathophysiology is necessary to improve the clinical management of this medical condition and form the basis of future research in this regard. In this review, we highlight the past and current definitions of PE and present an appraisal on the classifications and theories suggested for the etiopathogenesis of PE.

Hormonal correlations of premature ejaculation

Premature ejaculation is the most frequent male sexual dysfunction, significantly impairing quality of life of both the patient and the partner and affecting up to one-third of men of every age. In the last years, our knowledge about this topic has greatly increased, and studies on the causes and treatments related to ejaculatory disorders have shed a light on previously uncharted territory. Public interest on sexual dysfunctions has likewise increased in the general population: the time lapse between the first symptoms of sexual dysfunction and the seeking of medical advice has been significantly reduced, whereas demand for a treatment has markedly increased. A role of endocrine regulation has been established in all the aspects of male reproduction; however, the endocrine control of ejaculation is not fully understood. Sex steroid, pituitary, and thyroid hormones have all been advocated as potential candidates in the regulation of the ejaculatory process, but exact mechanisms are not clear yet and further studies are required in order to identify potential targets for treatment.

Nonresponders to daily paroxetine and another SSRI in men with lifelong premature ejaculation: a pharmacokinetic dose-escalation study for a rare phenomenon

Purpose

Nonresponse to any selective serotonin reuptake inhibitor (SSRI) treatment is rare. In this study, we aimed to investigate ejaculation delay nonresponse to paroxetine treatment in men with lifelong premature ejaculation (PE) who were also known to be nonresponders to other SSRIs.

Materials and Methods

Five males with lifelong PE who were known nonresponders to paroxetine and other serotonergic antidepressants and eight males with lifelong PE who were specifically recruited were included. Blood sampling occurred 1 month and 1 day before the start of treatment and at the end of three consecutive series of 4 weeks of daily treatment with 10-, 20-, and 30-mg paroxetine, respectively. Blood samples for measurement of leptin and paroxetine were taken at 8:30 AM, 9:30 AM, 10:30 AM, and 11:30 AM, respectively. At 9:00 AM, one tablet of 10-, 20-, or 30-mg paroxetine was taken during the first, second, and third month, respectively. Intravaginal ejaculatory latency time (IELT) was measured with a stopwatch. The main outcome measures were the fold increase in the geometric mean IELT, serum leptin and paroxetine concentrations, body mass index (BMI), 5-HT_1A receptor C-1019G polymorphism, and CYP2D6 mutations.

Results

Between the 7 paroxetine responders and 6 nonresponders, the fold increase in the geometric mean IELT was significantly different after daily 10-mg (p=0.003), 20-mg (p=0.002), and 30-mg paroxetine (p=0.026) and ranged from 2.0 to 8.8 and from 1.1 to 1.7, respectively. BMI at baseline and at the end of the study was not significantly different between responders and nonresponders. Serum leptin levels at baseline were similar in responders and nonresponders and did not change during treatment. The serum paroxetine concentration increased with increasing dosage and was not significantly different between responders and nonresponders. There was no association between the fold increase in the geometric mean IELT and serum paroxetine levels during the three treatment periods nor between leptin levels during the treatment periods and serum paroxetine levels. For the 5-HT_1A receptor C-1019G variation, all responders had the CC genotype and all nonresponders had the GC genotype, respectively.

Conclusions

Complete absence of paroxetine-induced ejaculation delay is presumably related to pharmacodynamic factors and perhaps to 5-HT_1A receptor gene polymorphism.

Sexual function improvement in association with serum leptin level elevation in patients with premature ejaculation following sertraline treatment: a preliminary observation

The objective of our work was to evaluate the effect of sertraline hydrochloride on serum levels of leptin and sexual function in patients with premature ejaculation (PE). A total of 124 patients with a history of PE at least 6 months, aged 20-50 years, were treated with sertraline hydrochloride. One hundred and four age-matched normal males without a history of PE were included control subjects and were untreated. Before and after the 8 week experiment, sexual performance parameters including the intravaginal ejaculation latency time (IELT) and the Chinese premature ejaculation index (CIPE) were collected from both PE patients and control subjects through a questionnaire survey and analyzed. Serum levels of leptin were measured. Correlations of serum leptin with Body Mass Index (BMI) were analyzed. Before sertraline treatment, serum levels of leptin were significantly higher (32.9 vs 8.8 μg/L, p<0.001) but IELT and CIPE score were significantly lower (54 vs 590, p <0.001; 8.7 vs 22.3, p <0.0001) in PE patients than control subjects. After 8 weeks of treatment with sertraline, serum levels of leptinl in PE patients were decreased markedly to 8.0 μg/L, which was not significantly different from the levels in control subjects (p >0.05); and IELT and CIPE score in PE patients were increased to the values similar to those in control subjects. The sensitivity and specificity values were 87.5% and 96.3% for leptin as a diagnosis target. These observations suggest sertraline as a selective serotonin reuptake inhibitor may offer an effective option for treating premature ejaculation.