Could androgen receptor gene CAG tract polymorphism affect spermatogenesis in men with idiopathic infertility?

PURPOSE: This study examined whether the AR-CAG repeat length might affect clinical characteristics (testis volume) seminal parameters (sperm count and its mobility) along with hormonal serum profile [FSH, LH, Testosterone (T) and Inhibin B (InhB)] both in idiopathic male infertility (IM) and in infertility due to a previous condition of cryptorchidism (CryM) or to Y chromosome long arm microdeletions (YM). DESIGN: Observational study without intervention(s). PATIENTS: One hundred and ten IM patients [90 idiopathic olizoospermic males (IOM) and 20 idiopathic azoospermic males (IAM)], 19 CryM male and 10 YM patients were included. Sixty-one age-matched healthy men who had fathered within 3 years were involved representing the control group (FM). RESULTS: AR-CAG repeats stretch was significantly longer in IOM (p<0.05), CryM (p<0.05) and YM (p<0.001) than FM. When the AR-CAG repeat tracts were subdivided in three subgroups according to the length of CAG repeats tract assessed in fertile subjects (the one with the middle (n 19-21) belonging to the 25 and 75 % inter-quartile, the ends belonging to the <25 % inter-quartile and >75 % inter-quartile, respectively), there was a statistically significant difference of distribution of AR-CAG tract length among fertile and different groups of infertile men (p=<0.0005; chi-square test). Moreover, the subgroup of AR-CAG repeat stretch with 22-28 triplets was associated with lower levels of InhB both in idiopathic oligozoospermic (Scheffe, Bonferroni and Dunett tests p=<0.01) and azoospermic men (Scheffe, Bonferroni and Dunett test p=<0.05), while, when FM and men with idiopathic infertility were gathered in a single group, both the subgroup of AR- CAG tract with 15-18 repeats and the one with 22-28 repeats are associated with lower testis volume, reduced sperm count and serum InhB levels. CONCLUSIONS: Our study showed that the outliers of AR-CAG repeat length seem to influence the function of AR, affecting testis volume and Sertoli cell function and consequently sperm production in both fertile and idiopathic infertile men.

Varicocele correction for infertility: which patients to treat?

Given the lack of clarity regarding the value of varicocele correction in improving male fertility, we examined whether divergent results in this regard could be attributed to selection of patients, especially with regard to the duration of their infertility or to the length of patients' androgen receptor CAG repeats. In a prospective study, involving all varicocele patients consulted consecutively for infertility, we compared the pregnancy rate (PR) over 1 year produced by patients who opted not to have varicocele correction after extensive information concerning fertility prospects (N = 185), with that by patients who had varicocele correction (N = 137). In the second study involving another smaller group of varicocele subjects (N = 72), we investigated whether CAG repeat length in the androgen receptor gene had any influence on fertility of varicocele-corrected patients. Overall, the PR in corrected and uncorrected varicocele groups did not differ significantly, but when subjects with infertility beyond 2 years were considered, varicocele-corrected subjects had a significantly greater PR than uncorrected varicocele patients (p = 0.025). Together with infertility duration, spermatozoa progressive motility appears the most important predictor of fertility, whereas neither grade of varicocele nor age of the couple (within the age limits of this study) influenced the outcome. Similarly, CAG repeat length did not affect the outcome of varicocele correction. These data suggest that varicocele correction at 1 year of infertility does not result in a significantly higher PR than that achieved by men with uncorrected varicocele. In view of the high spontaneous PR in subjects with an infertility of less than 2 years, varicocele correction aimed at restoring fertility appears to be most appropriate for men whose infertility extends beyond 2 years.

Adding liraglutide to lifestyle changes, metformin and testosterone therapy boosts erectile function in diabetic obese men with overt hypogonadism.

The aim of this retrospective observational study was to evaluate whether adding liraglutide to lifestyle changes, metformin (Met) and testosterone replacement therapy (TRT), by means of improving weight and glycaemic control, could boost erectile function in type 2 diabetic obese men with overt hypogonadism and erectile dysfunction (ED) in a 'real-life setting'. Forty-three obese, diabetic and hypogonadal men (aged 45-59 years) were evaluated because of complaining about the recent onset of ED. They were subdivided into two groups according to whether hypogonadism occurred after puberty (G1; n = 30: 25 with dysfunctional hypogonadism and 5 with acquired hypogonadotropic hypogonadism) or before puberty (G2; n = 13: 10 with Klinefelter's syndrome and 3 with idiopathic hypogonadotropic hypogonadism). Both G1 and G2 patients were given a combination of testosterone (T) [testosterone undecanoate (TU) 1000 mg/every 12 weeks] and Met (2000-3000 mg/day) for 1 year. In the poor responders (N) to this therapy in terms of glycaemic target (G1N: n = 16; G2N: n = 10), liraglutide (L) (1.2 µg/day) was added for a second year, while the good responders (Y) to T + Met (G1Y: 14/30 and G2Y: 3/13) continued this two drugs regimen therapy for another year. All patients were asked to fill in the International Index of Erectile Function (IIEF 15) questionnaire before starting TU plus Met (T1) and after 12 months (T2) and 24 months (T3) of treatment. Patients underwent a clinical examination and a determination of serum sex hormone binding globulin (SHBG), total testosterone (T) and glycosylated haemoglobin (HbA1c) at T1, T2 and T3. At T2, each patient obtained an improvement of ED (p < 0.01) and of the metabolic parameters without reaching, however, the glycaemic goals [HbA1c = >7.5% (>58 mmol/mol)], while T turned out to be within the range of young men. L added to TU and Met regimen in G1N and G2N allowed these patients to reach not only the glycaemic target [HbA1c = <7.5% (<58 nmol/mol)] and a significant reduction in body weight (p < 0.01), but also a further increase in SHBG (p < 0.05) and T (p < 0.01) plasma levels as well as a significant increment of IIEF score (T3). Conversely, at T3 G1Y and G2Y, who received the combined therapy with TRT and Met for the second year, showed a partial failure of that treatment given that there was no improvement of the IIEF score and they showed a significant rise in serum HbA1c (p < 0.05) and weight (p < 0.04) compared with the assessments at T2. These results suggest that TRT could improve clinical and metabolic parameters in obese, type 2 diabetic men with ED and overt hypogonadism (independently of when T deficit occurred). Furthermore, in case of insufficient metabolic control the addition of L to TRT and Met regimen allows to achieve serum T levels in the range of healthy men, as well as to reach glycaemic target and to lower weight, leading to a considerable improvement of ED.

Effectiveness of gonadotropin administration for spermatogenesis induction in hypogonadotropic hypogonadism: a possible role of androgen receptor CAG repeat polymorphism and therapeutic measures.

Prepuberal-onset (PRHH) and postpuberal-onset (PSHH) Hypogonadotropic Hypogondism (HH) refer to a heterogeneous group of patients, showing a broad spectrum of clinical signs and symptoms of androgen deficiency in consideration of the different possible aetiologies and the age at onset. These patients, though, required Gonadotropin treatment (GnTh) by means of administration of both the ß Human Chorionic Gonodadotropin (ß HCG) and the Follicle Stimulating Hormone (FSH) to obtain mature sperms in the ejaculate aiming to reach fertility levels. However, the response to GnTh is always unpredictable concerning either the effectiveness or the duration of the therapy. Consequently, different studies have been carried out to identify clinical (i.e. cryptorchidism, gynecomastia, testis size, etc) and biochemical markers [serum Testosterone (T) and Inhibin B (IB)] that can be useful to predict the effectiveness of GnTh. Given that the actions of T, even those directed at inducing and maintaining spermatogenesis, are mediated by its interaction with the Androgen Receptor (AR), we measured the AR CAG repeat polymorphism in men with HH, in order to examine whether the CAG polymorphism extensions could co-regulate the GnTh effectiveness. Twenty-three HH subjects were subdivided according to the age at onset (pre- and postpubertal) and treated with the same scheme and doses of GnTh, extending the period of treatment up to 30 months. Thirty-five healthy and fertile men served as a control group (CG). Twelve HH subjects (3 PRHH and 9 PSHH), who reached complete spermatogenesis within 12 months, showed the length of AR CAG repeat number [20 (19-23) = median (interquartile range 25th - 75th percentile)] not statistically different from our CG [20 (19-22)], while CAG repeat number [23 (20-25)] of 11 HH patients (9 PRHH and 2 PSHH) who obtained mature sperms in their ejaculate beyond a year to within 30 months, was significantly higher. Our results suggest that the length of AR CAG repeat polymorphism might affect the response to GnTh in men suffering from HH, in particular in those patients with prepubertal-onset hypogonadism.