Evidence-based definition of hypoprolactinemia in European men aged 40-86 years: the European male ageing study.

Empirical evidence for a low normal or reference interval for serum prolactin (PRL) is lacking for men, while the implications of very low PRL levels for human health have never been studied. A clinical state of "PRL deficiency" has not been defined except in relation to lactation. Using data from the European Male Ageing Study (EMAS), we analyzed the distribution of PRL in 3,369 community-dwelling European men, aged 40-80 years at phase-1 and free from acute illnesses. In total, 2,948 and 2,644 PRL samples were collected during phase-1 and phase-2 (3 to 5.7 years later). All samples were analysed in the same centre with the same assay. After excluding individuals with known pituitary diseases, PRL ≥ 35 ng/ml, and PRL-altering drugs including antipsychotic agents, selective serotonin reuptake inhibitors, or dopamine agonists, 5,086 data points (2,845 in phase-1 and 2,241 in phase-2) were available for analysis. The results showed that PRL declined minimally with age (slope = -0.02) and did not correlate with BMI. The positively skewed PRL distribution was log-transformed to a symmetrical distribution (skewness reduced from 13.3 to 0.015). Using two-sigma empirical rule (2[]SD about the mean), a threshold at 2.5% of the lower end of the distribution was shown to correspond to a PRL value of 2.98ng/ml. With reference to individuals with PRL levels of 5-34.9 ng/ml (event rate = 6.3%), the adjusted risk of developing type 2 diabetes increased progressively in those with PRL levels of 3-4.9 ng/ml: event rate = 9.3%, OR (95% CI) 1.59 (0.93-2.71), and more so with PRL levels of 0.3-2.9 ng/ml: event rate = 22.7%, OR 5.45 (1.78-16.62). There was also an increasing trend in prediabetes and diabetes based on fasting blood glucose levels was observed with lower categories of PRL. However, PRL levels were not associated with cancer, cardiovascular diseases, depressive symptoms or mortality. Our findings suggest that a PRL level below 3 ng/ml (64 mlU/l) significantly identifies European men with a clinically-important outcome (of type 2 diabetes), offering a lower reference-value for research and clinical practice.

Insulin-like peptide 3 (INSL3) as an indicator of leydig cell insufficiency (LCI) in Middle-aged and older men with hypogonadism: reference range and threshold.

Insulin-like peptide 3 (INSL3) is a circulating biomarker for Leydig cell functional capacity in men, also indicating Leydig Cell Insufficiency (LCI) and potential primary hypogonadism. Using results from large cohort studies we explore sources of biological and technical variance, and establish a reference range for adult men. It is constitutively secreted with little within-individual variation and reflects testicular capacity to produce testosterone. The main INSL3 assays available indicate good concordance with low technical variance; there is no effect of ethnicity. INSL3 declines with age from 35 years at about 15% per decade. Like low calculated free testosterone, and to a lesser extent low total testosterone, reduced INSL3 is significantly associated with increasing age-related morbidity, including lower overall sexual function, reflecting LCI. Consequently, low INSL3 (≤0.4 ng/ml; ca. <2 SD from the population mean) might serve as an additional biochemical marker in the assessment of functional hypogonadism (late-onset hypogonadism, LOH) where testosterone is in the borderline low range. Excluding individuals with low LCI (INSL3 ≤ 0.4 ng/ml) leads to an age-independent (> 35 years) reference range (serum) for INSL3 in the eugonadal population of 0.4 - 2.3 ng/ml, with low INSL3 prospectively identifying individuals at risk of increased future morbidity.

Number of CAG repeats and mortality in middle aged and older men.

DESIGN: The androgen receptor (AR) mediates peripheral effects of testosterone. Previous data suggests an association between the number of CAG repeats in exon-1 of the AR gene and AR transcriptional activity. The aim of this analysis was to determine the association between the number of AR CAG repeats and all-cause mortality in men and the influence of testosterone level on the association. PATIENTS AND MEASUREMENTS: Follow-up data to 27 January 2018 were available for men aged 40-79 years recruited across six countries of the European Male Aging Study between 2003 and 2005. Cox proportional hazards modelling was used to determine the association between CAG repeat number/mortality. Results were expressed as hazard ratios (HR)/95% confidence intervals (CI). RESULTS: One thousand nine hundred and seventy-seven men were followed up. Mean baseline age was 60 ± 11.1 years. Mean duration of follow-up was 12.2 years. At follow up 25.1% of men had died. CAG repeat length ranged from 6 to 39, with the highest proportion of CAG repeat number at 21 repeats (16.4%). In a multivariable model, compared to men with 22-23 AR CAG repeats: for men with <22 and >23 AR CAG HR, 95% CI for mortality were, <22 CAG repeats 1.17 (0.93-1.49) and >23 CAG repeats 1.14 (0.88-1.47). In a post-hoc analysis, the association was significant for men in the lowest tertile of baseline testosterone (<14.2 nmol/L) with >23 CAG repeats: in the adjusted model for <22 and >23 CAG repeats, respectively, 1.49 (0.97-2.27) and 1.68 (1.06-2.67) versus 22-23 repeats. CONCLUSIONS: Our European-wide cohort data overall found no association of androgen receptor CAG repeat number and mortality in men. However, post hoc analysis suggested that an association might be present in men with lower baseline testosterone concentrations, which merits further investigation.

Persistently expressed human chorionic gonadotropin induces premature luteinization and progressive alterations on the reproductive axis in female mice.

The hypothalamic-pituitary-gonadal axis plays a fundamental role in the endocrine regulation of the reproductive function in mammals. Any change in the function of the participating hormones or their receptors can lead to alterations in sexual differentiation, the onset of puberty, infertility, cancer development, and other dysfunctions. In this study, we analyzed the influence of persistently elevated levels of the human chorionic gonadotropin hormone (hCG), a powerful agonist of pituitary luteinizing hormone (LH), on the reproductive axis of female mice. As a consequence of chronic hCG hypersecretion through a global expression of the hCGbeta-subunit in transgenic (TG) female mice, a series of events perturbed the prepubertal to juvenile transition. The imbalance in gonadotropin action was first manifested by precocious puberty and alterations in gonadal hormone production, with the consequent ovarian function disruption and infertility in adulthood. The expansion of cumulus cells in vivo and in vitro, ovulatory capacity, and gene expression of ovulation-related marker genes after hormone stimulation were normal in 3-week-old TG females. However, the expression of genes related to steroidogenesis and luteinization such as Lhcgr, Prlr, and the steroidogenic enzymes Cyp11a1, Cyp17a1, and Cyp19a1 were significantly elevated in the TG females. This study demonstrates that the excessive secretion of hCG in concert with high prolactin, induced premature luteinization, and enhanced ovarian steroidogenesis, as was shown by the up-regulation of luteal cell markers and progesterone synthesis in the TG mice. Furthermore, progressively impaired reproductive function of the TG females occurred from the peripubertal stage to adulthood, thus culminating in infertility.

Does testosterone influence the association between sleep and frailty in men: results from the European Male Aging Study.

BACKGROUND: Previous studies have suggested an association between sleep disturbance and frailty. The mechanism is unknown, although it has been suggested that hormonal factors may play a role. METHODS: The aim was to determine the association between sleep duration, sleep quality and frailty, and to determine whether testosterone influenced this association. Males aged 40-79 years were recruited from eight European centres to the European Male Aging Study (EMAS). Subjects completed an interviewer-assisted questionnaire including questions regarding sleep quality and duration. Sleep quality was scored 0-20 and categorised as 0-4, 5-9, 10-14, and 15-20, with higher scores indicating poorer quality. A 39-component frailty index (FI) was constructed. Total testosterone levels were measured. The association between sleep duration, sleep quality and the FI was assessed using negative binomial regression, with adjustment for putative confounders including testosterone level. RESULTS: Two thousand three hundred ninety-three participants contributed data to the analysis. The mean age was 63.3 years and mean sleep duration was 7.01 h. The mean frailty index was 0.15. Mean testosterone levels declined with decreasing sleep quality. After adjustment, compared to those with a sleep score of 0-4, the FI was 57% (95% CI 38%, 78%) higher among those with a sleep score of 15-20. After adjustment compared to those with normal sleep duration (6-9 h), those with a short (< 6 h) and long (≥ 9 h) sleep duration had a 16% (95% CI 6%, 28%) and 11% (95% CI 0%, 23%) higher FI, respectively. Adjustment for testosterone did not influence the strength of either association. CONCLUSION: Frailty is associated with impaired sleep quality and sleep duration. The association cannot, however, be explained by variation in testosterone levels.

Follicle-stimulating hormone promotes growth of human prostate cancer cell line-derived tumor xenografts.

Chemical castration in prostate cancer can be achieved with gonadotropin-releasing hormone (GnRH) agonists or antagonists. Their effects differ by the initial flare of gonadotropin and testosterone secretion with agonists and the immediate pituitary-testicular suppression by antagonists. While both suppress luteinizing hormone (LH) and follicle-stimulating hormone (FSH) initially, a rebound in FSH levels occurs during agonist treatment. This rebound is potentially harmful, taken the expression of FSH receptors (R) in prostate cancer tissue. We herein assessed the role of FSH in promoting the growth of androgen-independent (PC-3, DU145) and androgen-dependent (VCaP) human prostate cancer cell line xenografts in nude mice. Gonadotropins were suppressed with the GnRH antagonist degarelix, and effects of add-back human recombinant FSH were assessed on tumor growth. All tumors expressed GnRHR and FSHR, and degarelix treatment suppressed their growth. FSH supplementation reversed the degarelix-evoked suppression of PC-3 tumors, both in preventive (degarelix and FSH treatment started upon cell inoculation) and therapeutic (treatments initiated 3 weeks after cell inoculation) setting. A less marked, though significant FSH effect occurred in DU145, but not in VCaP xenografts. FSHR expression in the xenografts supports direct FSH stimulation of tumor growth. Testosterone supplementation, to maintain the VCaP xenografts, apparently masked the FSH effect on their growth. Treatment with the LH analogue hCG did not affect PC-3 tumor growth despite their expression of luteinizing hormone/choriongonadotropin receptor. In conclusion, FSH, but not LH, may directly stimulate the growth of androgen-independent prostate cancer, suggesting that persistent FSH suppression upon GnRH antagonist treatment offers a therapeutic advantage over agonist.

Erectile dysfunction predicts mortality in middle-aged and older men independent of their sex steroid status.

BACKGROUND: erectile dysfunction is associated with mortality, whereas the association between low testosterone (T) and higher mortality remains controversial. Sexual dysfunction and low T often coexist, but the relative importance of sexual symptoms versus low T in predicting mortality is not known. We studied the interrelationships between sex steroids and sexual symptoms with all-cause mortality in a large prospective cohort of European men. DESIGN: survival status was assessed in 1,788 community-dwelling men, aged 40-79, who participated in the European Male Ageing Study (EMAS). Sexual symptoms were evaluated via a validated questionnaire (EMAS-SFQ). Sex steroids were measured by mass spectrometry. Cox proportional hazard models were used to study the association between hormones, sexual symptoms and mortality. RESULTS: about 420 (25.3%) men died during a mean follow-up of 12.6 ± 3.1 years. Total T levels were similar in both groups, but free T was lower in those who died. Men with three sexual symptoms (erectile dysfunction, reduced morning erections and lower libido) had a higher mortality risk compared with men with none of these symptoms (adjusted hazard ratio (HR) and 95% confidence intervals: 1.75 (1.28-2.40, P = 0.001)). Particularly, erectile dysfunction and poor morning erections, but not lower libido, were associated with increased mortality (HR 1.40 (1.13-1.74, P = 0.002), 1.28 (1.04-1.59, P = 0.023) and 1.12 (0.90-1.39, P = 0.312), respectively). Further adjusting for total T, free T or oestradiol did not influence the observed risk. CONCLUSIONS: sexual symptoms, in particular erectile dysfunction, predict all-cause mortality independently of sex steroids and can be an early warning sign of a poor health status.

Self-Reported Shorter Than Desired Ejaculation Latency and Related Distress-Prevalence and Clinical Correlates: Results From the European Male Ageing Study.

BACKGROUND: Few data have looked at the occurrence and clinical correlates of self-reported shorter than desired ejaculation latency (rapid ejaculation, RE) and its related distress in the general population. AIM: To determine the prevalence and clinical correlates of self-reported RE and RE- related distress in middle age and older European men. METHODS: Subjects were recruited from population samples of men aged 40-79 years across 8 European centers. OUTCOMES: Self-reported RE and its related distress were derived from the European male Aging Study (EMAS) sexual function questionnaire (EMAS-SFQ). Beck's depression Inventory (BDI) was used for the quantification of depressive symptoms, the Short Form 36 health survey (SF-36) for the assessment of the quality of life, the International Prostate Symptom Score (IPSS) for the evaluation of lower urinary tract symptoms. RESULTS: About 2,888 community dwelling men aged 40-79 years old (mean 58.9 ± 10.8 years) were included in the analysis. Among the subjects included, 889 (30.8%) self-reported RE. Among them, 211 (7.3%) claimed to be distressed (5.9% and 1.4% reported mild or moderate-severe distress, respectively). Increasing levels of RE-related distress were associated with a progressive worse sexual functioning, higher risk of ED and with couple impairment, along with a higher prevalence of depressive symptoms (all P < 0.05). Furthermore, a worse quality of life and higher IPSS score were associated with RE-related distress (all P < 0.05). The aforementioned results were confirmed even when patients using drugs possibly interfering with ejaculation or those without a stable relationship were excluded from the analysis. CLINICAL IMPLICATIONS: RE is a frequent condition in men from the general population; however, its related distress is relatively modest. Nonetheless, men with any degree of self-reported RE show increasing levels of depression, worse quality of life and worse couple satisfaction. STRENGTHS & LIMITATIONS: This is the first study estimating the prevalence of self-reported RE and its related distress, along with their biological and psychological correlates, in a population sample of European middle age and older men. However, is should be recognized that the diagnosis of RE was derived from patient reports and not supported by Intra-ejaculatory-Latency-Time (IELT) measurements. CONCLUSION: Self-reported RE is relatively common in European men aged more than 40 years. The reported limited RE-related distress may explain the relatively low number of medical consultations for RE. RE-related distress is associated with worse sexual function, couple impairment, and more LUTS resulting in a worse quality of life and mood disturbances. Corona G, Rastrelli G, Bartfai G, et al. Self-Reported Shorter Than Desired Ejaculation Latency and Related Distress-Prevalence and Clinical Correlates: Results From the European Male Ageing Study. J Sex Med Rev 2021;18:908-919.

The Roles of Luteinizing Hormone, Follicle-Stimulating Hormone and Testosterone in Spermatogenesis and Folliculogenesis Revisited.

Spermatogenesis and folliculogenesis involve cell-cell interactions and gene expression orchestrated by luteinizing hormone (LH) and follicle-stimulating hormone (FSH). FSH regulates the proliferation and maturation of germ cells independently and in combination with LH. In humans, the requirement for high intratesticular testosterone (T) concentration in spermatogenesis remains both a dogma and an enigma, as it greatly exceeds the requirement for androgen receptor (AR) activation. Several data have challenged this dogma. Here we report our findings on a man with mutant LH beta subunit (LHß) that markedly reduced T production to 1-2% of normal., but despite this minimal LH stimulation, T production by scarce mature Leydig cells was sufficient to initiate and maintain complete spermatogenesis. Also, in the LH receptor (LHR) knockout (LuRKO) mice, low-dose T supplementation was able to maintain spermatogenesis. In addition, in antiandrogen-treated LuRKO mice, devoid of T action, the transgenic expression of a constitutively activating follicle stimulating hormone receptor (FSHR) mutant was able to rescue spermatogenesis and fertility. Based on rodent models, it is believed that gonadotropin-dependent follicular growth begins at the antral stage, but models of FSHR inactivation in women contradict this claim. The complete loss of FSHR function results in the complete early blockage of folliculogenesis at the primary stage, with a high density of follicles of the prepubertal type. These results should prompt the reassessment of the role of gonadotropins in spermatogenesis, folliculogenesis and therapeutic applications in human hypogonadism and infertility.

Elevated luteinizing hormone despite normal testosterone levels in older men-natural history, risk factors and clinical features.

OBJECTIVE: Elevated luteinizing hormone (LH) with normal testosterone (T) suggests compensated dysregulation of the gonadal axis. We describe the natural history, risk factors and clinical parameters associated with the development of high LH (HLH, LH >9.4 U/L) in ageing men with normal T (T ≥ 10.5 nmol/L). DESIGN, PATIENTS AND MEASUREMENTS: We conducted a 4.3-year prospective observational study of 3369 community-dwelling European men aged 40-79 years. Participants were classified as follows: incident (i) HLH (n = 101, 5.2%); persistent (p) HLH (n = 128, 6.6%); reverted (r) HLH (n = 46, 2.4%); or persistent normal LH (pNLH, n = 1667, 85.8%). Potential predictors and changes in clinical features associated with iHLH and rHLH were analysed using regression models. RESULTS: Age >70 years (OR = 4.12 [2.07-8.20]), diabetes (OR = 2.86 [1.42-5.77]), chronic pain (OR = 2.53 [1.34-4.77]), predegree education (OR = 1.79 [1.01-3.20]) and low physical activity (PASE ≤ 78, OR = 2.37 [1.24-4.50]) predicted development of HLH. Younger age (40-49 years, OR = 8.14 [1.35-49.13]) and nonsmoking (OR = 5.39 [1.48-19.65]) predicted recovery from HLH. Men with iHLH developed erectile dysfunction, poor health, cardiovascular disease (CVD) and cancer more frequently than pNLH men. In pHLH men, comorbidities, including CVD, developed more frequently, and cognitive and physical function deteriorated more, than in pNLH men. Men with HLH developed primary hypogonadism more frequently (OR = 15.97 [5.85-43.60]) than NLH men. Men with rHLH experienced a small rise in BMI. CONCLUSIONS: Elevation of LH with normal T is predicted by multiple factors, reverts frequently and is not associated with unequivocal evidence of androgen deficiency. High LH is a biomarker for deteriorating health in aged men who tend to develop primary hypogonadism.

Symptomatic androgen deficiency develops only when both total and free testosterone decline in obese men who may have incident biochemical secondary hypogonadism: Prospective results from the EMAS.

OBJECTIVE: Limited evidence supports the use of free testosterone (FT) for diagnosing hypogonadism when sex hormone-binding globulin (SHBG) is altered. Low total testosterone (TT) is commonly encountered in obesity where SHBG is typically decreased. We aimed to assess the contribution of FT in improving the diagnosis of symptomatic secondary hypogonadism (SH), identified initially by low total testosterone (TT), and then further differentiated by normal FT (LNSH) or low FT (LLSH). DESIGN: Prospective observational study with a median follow-up of 4.3 years. PATIENTS: Three thousand three hundred sixty-nine community-dwelling men aged 40-79 years from eight European centres. MEASUREMENTS: Subjects were categorized according to baseline and follow-up biochemical status into persistent eugonadal (referent group; n = 1880), incident LNSH (eugonadism to LNSH; n = 101) and incident LLSH (eugonadism to LLSH; n = 38). Predictors and clinical features associated with the transition from eugonadism to LNSH or LLSH were assessed. RESULTS: The cumulative incidence of LNSH and LLSH over 4.3 years was 4.9% and 1.9%, respectively. Baseline obesity predicted both LNSH and LLSH, but the former occurred more frequently in younger men. LLSH, but not LNSH, was associated with new/worsened sexual symptoms, including low desire [OR = 2.67 (1.27-5.60)], erectile dysfunction [OR = 4.53 (2.05-10.01)] and infrequent morning erections [OR = 3.40 (1.48-7.84)]. CONCLUSIONS: These longitudinal data demonstrate the importance of FT in the diagnosis of hypogonadism in obese men with low TT and SHBG. The concurrent fall in TT and FT identifies the minority (27.3%) of men with hypogonadal symptoms, which were not present in the majority developing low TT with normal FT.

Novel Role for p110ß PI 3-Kinase in Male Fertility through Regulation of Androgen Receptor Activity in Sertoli Cells.

The organismal roles of the ubiquitously expressed class I PI3K isoform p110ß remain largely unknown. Using a new kinase-dead knockin mouse model that mimics constitutive pharmacological inactivation of p110ß, we document that full inactivation of p110ß leads to embryonic lethality in a substantial fraction of mice. Interestingly, the homozygous p110ß kinase-dead mice that survive into adulthood (maximum ~26% on a mixed genetic background) have no apparent phenotypes, other than subfertility in females and complete infertility in males. Systemic inhibition of p110ß results in a highly specific blockade in the maturation of spermatogonia to spermatocytes. p110ß was previously suggested to signal downstream of the c-kit tyrosine kinase receptor in germ cells to regulate their proliferation and survival. We now report that p110ß also plays a germ cell-extrinsic role in the Sertoli cells (SCs) that support the developing sperm, with p110ß inactivation dampening expression of the SC-specific Androgen Receptor (AR) target gene Rhox5, a homeobox gene critical for spermatogenesis. All extragonadal androgen-dependent functions remain unaffected by global p110ß inactivation. In line with a crucial role for p110ß in SCs, selective inactivation of p110ß in these cells results in male infertility. Our study is the first documentation of the involvement of a signalling enzyme, PI3K, in the regulation of AR activity during spermatogenesis. This developmental pathway may become active in prostate cancer where p110ß and AR have previously been reported to functionally interact.

Luteinizing Hormone and GATA4 Action in the Adrenocortical Tumorigenesis of Gonadectomized Female Mice.

BACKGROUND/AIMS: Physiological role of luteinizing hormone (LH) and its receptor (LHCGR) in adrenal remains unknown. In inhibin-α/Simian Virus 40 T antigen (SV40Tag) (inhα/Tag) mice, gonadectomy-induced (OVX) elevated LH triggers the growth of transcription factor GATA4 (GATA4)-positive adrenocortical tumors in a hyperplasia-adenoma-adenocarcinoma sequence. METHODS: We investigated the role of LHCGR in tumor induction, by crossbreeding inhα/Tag with Lhcgr knockout (LuRKO) mice. By knocking out Lhcgr and Gata4 in Cα1 adrenocortical cells (Lhcgr-ko, Gata4-ko) we tested their role in tumor progression. RESULTS: Adrenal tumors of OVX inhα/Tag mice develop from the hyperplastic cells localized in the topmost layer of zona fasciculata. OVX inhα/Tag/LuRKO only developed SV40Tag positive hyperplastic cells that were GATA4 negative, cleaved caspase-3 positive and did not progress into adenoma. In contrast to Lhcgr-ko, Gata4-ko Cα1 cells presented decreased proliferation, increased apoptosis, decreased expression of Inha, SV40Tag and Lhcgr tumor markers, as well as up-regulated adrenal- and down-regulated sex steroid gene expression. Both Gata4-ko and Lhcgr-ko Cα1 cells had decreased expression of steroidogenic genes resulting in decreased basal progesterone production. CONCLUSION: Our data indicate that LH/LHCGR signaling is critical for the adrenal cell reprogramming by GATA4 induction prompting adenoma formation and gonadal-like phenotype of the adrenocortical tumors in inhα/Tag mice.

Glycemia but not the Metabolic Syndrome is Associated with Cognitive Decline: Findings from the European Male Ageing Study.

OBJECTIVE: Previous research has indicated that components of the metabolic syndrome (MetS), such as hyperglycemia and hypertension, are negatively associated with cognition. However, evidence that MetS itself is related to cognitive performance has been inconsistent. This longitudinal study investigates whether MetS or its components affect cognitive decline in aging men and whether any interaction with inflammation exists. METHODS: Over a mean of 4.4 years (SD ± 0.3), men aged 40-79 years from the multicenter European Male Ageing Study were recruited. Cognitive functioning was assessed using the Rey-Osterrieth Complex Figure (ROCF), the Camden Topographical Recognition Memory (CTRM) task, and the Digit Symbol Substitution Test (DSST). High-sensitivity C-reactive protein (hs-CRP) levels were measured using a chemiluminescent immunometric assay. RESULTS: Overall, 1,913 participants contributed data to the ROCF analyses and 1,965 subjects contributed to the CTRM and DSST analyses. In multiple regression models the presence of baseline MetS was not associated with cognitive decline over time (p > 0.05). However, logistic ordinal regressions indicated that high glucose levels were related to a greater risk of decline on the ROCF Copy (ß = -0.42, p < 0.05) and the DSST (ß = -0.39, p < 0.001). There was neither a main effect of hs-CRP levels nor an interaction effect of hs-CRP and MetS at baseline on cognitive decline. CONCLUSION: No evidence was found for a relationship between MetS or inflammation and cognitive decline in this sample of aging men. However, glycemia was negatively associated with visuoconstructional abilities and processing speed.

Evaluation of cognitive subdomains, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D in the European Male Ageing Study.

PURPOSE: Although lower levels of vitamin D have been related to poor cognitive functioning and dementia in older adults, evidence from longitudinal investigations is inconsistent. The objective of this study was to determine whether 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] levels are associated with specified measures of cognitive decline in ageing men. METHODS: The European Male Ageing Study (EMAS) followed 3369 men aged 40-79 over 4.4 years. 25(OH)D levels at baseline were measured by radioimmunoassay, and 1,25(OH)2D levels were obtained with liquid chromatography-tandem mass spectrometry. Visuoconstructional abilities, visual memory, and processing speed at baseline and follow-up were assessed using the Rey-Osterrieth Complex Figure Test (ROCF), Camden Topographical Recognition Memory (CTRM), and the Digit Symbol Substitution Test (DSST). RESULTS: Following attritions, a total of 2430 men with a mean (SD) age of 59.0 (10.6) were included in the analyses. At baseline, the mean 25(OH)D concentration was 64.6 (31.5) nmol/l, and mean 1,25(OH)2D level was 59.6 (16.6) pmol/l. In age-adjusted linear regression models, high 25(OH)D concentrations were associated with a smaller decline in the DSST (ß = 0.007, p = 0.020). Men with low 25(OH)D levels (<50 nmol/l) showed a greater decline in the CTRM compared to men with higher (≥75 nmol/l) levels (ß = -0.41, p = 0.035). However, these associations disappeared after adjusting for confounders such as depressive symptoms, BMI, and comorbidities. There was no indication of a relationship between 1,25(OH)2D and decline in cognitive subdomains. CONCLUSION: We found no evidence for an independent association between 25(OH)D or 1,25(OH)2D levels and visuoconstructional abilities, visual memory, or processing speed over on average 4.4 years in this sample of middle-aged and elderly European men.

Frailty and bone health in European men.

Background: frailty is associated with an increased risk of fragility fractures. Less is known, however, about the association between frailty and bone health. Methods: men aged 40-79 years were recruited from population registers in eight European centres for participation in the European Male Aging Study. Subjects completed a comprehensive assessment which included quantitative ultrasound (QUS) scan of the heel (Hologic-SAHARA) and in two centres, dual-energy bone densitometry (dual-energy x-ray absorptiometry, DXA). Frailty was defined based on an adaptation of Fried's phenotype criteria and a frailty index (FI) was constructed. The association between frailty and the QUS and DXA parameters was determined using linear regression, with adjustments for age, body mass index and centre. Results: in total, 3,231 subjects contributed data to the analysis. Using the Fried categorisation of frailty, pre-frail and frail men had significantly lower speed of sound (SOS), broadband ultrasound attenuation (BUA) and quantitative ultrasound index (QUI) compared to robust men (P< 0.05). Similar results were seen using the FI after categorisation into 'high', 'medium' and 'low' levels of frailty. Using the Fried categorisation, frail men had lower femoral neck bone mineral density (BMD) compared to robust men (P < 0.05), but not lower lumbar spine BMD. Using the FI categorisation, a 'high' level of frailty (FI > 0.35) was associated with lower lumbar spine BMD (P < 0.05) when compared to those with low (FI < 0.2), but not lower femoral neck BMD. When analysed as a continuous variable, higher FI was linked with lower SOS, BUA and QUI (P < 0.05). Conclusions: optimisation of bone health as well as prevention of falls should be considered as strategies to reduce fractures in frail older people.

Single molecule analysis of functionally asymmetric G protein-coupled receptor (GPCR) oligomers reveals diverse spatial and structural assemblies.

Formation of G protein-coupled receptors (GPCRs) into dimers and higher order oligomers represents a key mechanism in pleiotropic signaling, yet how individual protomers function within oligomers remains poorly understood. We present a super-resolution imaging approach, resolving single GPCR molecules to ∼ 8 nm resolution in functional asymmetric dimers and oligomers using dual-color photoactivatable dyes and localization microscopy (PD-PALM). PD-PALM of two functionally defined mutant luteinizing hormone receptors (LHRs), a ligand-binding deficient receptor (LHR(B-)) and a signaling-deficient (LHR(S-)) receptor, which only function via intermolecular cooperation, favored oligomeric over dimeric formation. PD-PALM imaging of trimers and tetramers revealed specific spatial organizations of individual protomers in complexes where the ratiometric composition of LHR(B-) to LHR(S-) modulated ligand-induced signal sensitivity. Structural modeling of asymmetric LHR oligomers strongly aligned with PD-PALM-imaged spatial arrangements, identifying multiple possible helix interfaces mediating inter-protomer associations. Our findings reveal that diverse spatial and structural assemblies mediating GPCR oligomerization may acutely fine-tune the cellular signaling profile.

Natural history, risk factors and clinical features of primary hypogonadism in ageing men: Longitudinal Data from the European Male Ageing Study.

OBJECTIVE: In ageing men, the incidence and clinical significance of testosterone (T) decline accompanied by elevated luteinizing hormone (LH) are unclear. We describe the natural history, risk factors and clinical features associated with the development of biochemical primary hypogonadism (PHG, T < 10·5 nmol/l and LH>9·4U/l) in ageing men. DESIGN, PATIENTS AND MEASUREMENTS: A prospective observational cohort survey of 3,369 community-dwelling men aged 40-79 years, followed up for 4·3 years. Men were classified as incident (i) PHG (eugonadal [EUG, T ≥ 10·5 nmol/l] at baseline, PHG at follow-up), persistent (p) PHG (PHG at baseline and follow-up), pEUG (EUG at baseline and follow-up) and reversed (r) PHG (PHG at baseline, EUG at follow-up). Predictors and changes in clinical features associated with the development of PHG were analysed by regression models. RESULTS: Of 1,991 men comprising the analytical sample, 97·5% had pEUG, 1·1% iPHG, 1·1% pPHG and 0·3% rPHG. The incidence of PHG was 0·2%/year. Higher age (>70 years) [OR 12·48 (1·27-122·13), P = 0·030] and chronic illnesses [OR 4·24 (1·08-16·56); P = 0·038] predicted iPHG. Upon transition from EUG to PHG, erectile function, physical vigour and haemoglobin worsened significantly. Men with pPHG had decreased morning erections, sexual thoughts and haemoglobin with increased insulin resistance. CONCLUSIONS: Primary testicular failure in men is uncommon and predicted by old age and chronic illness. Some clinical features attributable to androgen deficiency, but not others, accompanied the T decline in men who developed biochemical PHG. Whether androgen replacement can improve sexual and/or physical function in elderly men with PHG merits further study.

Imbalanced lipid homeostasis in the conditional Dicer1 knockout mouse epididymis causes instability of the sperm membrane.

During epididymal sperm maturation, the lipid content of the sperm membrane is modified, which facilitates sperm motility and fertility. However, little is known about the mechanisms regulating the maturation process. By generating a conditional knockout (cKO) of Dicer1 in the proximal part of the mouse epididymis, we studied the role of RNA interference in epididymal functions. The Dicer1 cKO epididymis displayed an altered lipid homeostasis associated with a 0.6-fold reduction in the expression of the gene elongation of very long chain fatty acids-like 2, an enzyme needed for production of long-chain polyunsaturated fatty acids (PUFAs). Furthermore, the expression of several factors involved in cholesterol synthesis was up-regulated. Accordingly, the Dicer1 cKO sperm membrane showed a 0.7-fold decrease in long-chain PUFAs, whereas the amount of cholesterol in acrosome-reacted sperm displayed a 1.7-fold increase. The increased cholesterol:PUFA ratio of the sperm membrane caused breakage of the neck and acrosome region and immotility of sperm. Dicer1 cKO mice sperm also displayed reduced ability to bind to and fertilize the oocyte in vitro. This study thus shows that Dicer1 is critical for lipid synthesis in the epididymis, which directly affects sperm membrane integrity and male fertility.