Systematic review and meta-analysis of candidate gene association studies of lower urinary tract symptoms in men. Eur Urol. 2014;66:752-768. [PMID: 24491308 PMCID: PMC4410299 DOI: 10.1016/j.eururo.2014.01.007]

Evidence-based Urology: When Is a Study or Meta-analysis Big Enough?

Both designing a clinical study and drawing conclusions from studies about the effect of treatments require justification of the sample size via judicious choice of the endpoint and power. Such an a priori power calculation limits the chances of mistakenly claiming a lack of clinical significance if no statistically significant difference between two treatments can be detected. Calculating the sample size for a new trial furthermore requires assessment of existing evidence to determine if its results will contribute to an updated meta-analysis. To rate the power of a meta-analysis, determination of the optimal information size is suggested, following the same principles as for calculating the power of a single trial. Even though these sample size considerations might seem like an additional hurdle, they are necessary to conduct clinical studies and meta-analysis that provide the optimal benefit for both clinicians and patients. PATIENT SUMMARY: Before conducting a clinical trial, researchers should determine how many patients need to be included to detect a difference between treatments. Even though a study might find a statistical difference between treatments, this does not necessarily mean that the difference is relevant for clinical use. These analyses before starting a study are important for producing worthwhile usable evidence for clinicians and patients.

Association of TERT gene polymorphisms with clinical benign prostatic hyperplasia in a Chinese Han population of the Northwest region

Background

To investigate the association between single nucleotide polymorphisms (rs10078761, rs12696304, rs2853669, rs16847897, rs2736100, rs10069690) of telomerase gene (TERT) and the risk clinical benign prostatic hyperplasia (BPH) in a Chinese Han population of the Northwest region.

Methods

A total of 150 BPH patients and 150 healthy older males from the northwest Chinese Han population were included in this study. The sample size for this unmatched case-control study was estimated by the look-up table method. Meanwhile, the general information and disease data of patients were collected. Age was only collected in healthy control subjects for statistical correction. Genotypes were detected using a multiplex PCR + ligase detection reaction (LDR). Typing results and clinical data were statistically analyzed using multiple linear regression and logistic regression. Pearson correlation was used for Hardy-Weinberg equilibrium.

Results

The included population is in Hardy-Weinberg equilibrium. There was no significant association between SNP and the risk of BPH by correlation analysis. However, 4 haplotypes (TCTGGT, TCTGTC, TGCCTC, and TGTGTC) were identified as risk factors of BPH by haplotype analysis. The SNP rs2853669 is an independent risk factor for smooth muscle type of hyperplasia. Besides, rs2736100, rs10078761, and rs10069690 which are in linkage disequilibrium are associated with the severity of BPH.

Conclusions

Polymorphism of the TERT gene determines the different disease development and pathological manifestations of BPH in the Chinese Han population the Northwest region.

Urgency urinary incontinence, loss of independence, and increased mortality in older adults: A cohort study

Objectives

To investigate the longitudinal association of urgency urinary incontinence (UUI) with loss of independence (LOI) or death among independent community-dwelling older adults.

Design

Population-based cohort study.

Setting

The Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS), Minami-Aizu Town and Tadami Town, Fukushima, Japan.

Participants

A total of 1,580 participants aged ≥65 years who underwent a health check-up conducted by LOHAS in 2010.

Measurements

Exposure was defined as the presence of UUI, which was measured by a questionnaire based on the definition of UUI from the International Continence Society. The primary outcome was defined as incidence of LOI or death. After the check-up in 2010, the outcome was monitored until March 2014. A multivariable Cox proportional hazard analysis was performed to estimate the hazard ratio for the outcome. Ten potential confounders were adjusted in the analysis. Furthermore, we defined the secondary outcomes as two separate outcomes, LOI and death, and performed the same analysis.

Results

Among all participants, 328 reported UUI. The incidence rates of the outcome were 20.4 and 11.4 (per 1,000 person–years) among participants with and without UUI, respectively. After multivariable adjustment, those who experienced UUI showed a substantial association with LOI or death (HR, 1.65; 95% CI, 1.01–2.68). However, they did not show such an association with LOI alone (HR, 1.07; 95% CI, 0.49–2.33). On the other hand, those with UUI exhibited a substantial association with death (HR, 2.23; 95% CI, 1.22–4.31).

Conclusions

In this study, UUI was associated with the occurrence of LOI or death; however, UUI is not associated with the occurrence of LOI alone among independent community-dwelling older adults. Our results suggest that there may be a difference between UUI-associated diseases that cause LOI and those that cause death.

Diastasis recti abdominis and pelvic floor dysfunction in peri- and postmenopausal women: a cross-sectional study

Introduction: Diastasis recti abdominis (DRA) and pelvic floor dysfunction (PFD) occurs commonly with aging; however, little is known about what leads to these changes.Objective: We aimed to investigate and compare the presence or absence of DRA and PFD in peri- and postmenopausal women.Methods: This cross-sectional study involved 150 participants who answered questions on their sociodemographic and clinical profiles related to urinary and fecal incontinence and pelvic organ prolapse. Diastasis recti abdominis was diagnosed with a digital caliper.Results: Supra-umbilical diastasis occurred in 37.3% of cases, and 78.6% of participants with DRA had PFD. No significant differences existed between participants with and without DRA in terms of background and clinical variables. However, participants with DRA were 2.6 times more likely to have PFD than participants without DRA. Furthermore, the presence of DRA was significantly shown to be a risk factor for PFD on binary logistic regression analyses (p = .01, OR = 3.2).Conclusions: This cross-sectional study suggests that DRA is a predictive factor of PFD in women aged over 50 years.

Genome-Wide Association Study for Urinary and Fecal Incontinence in Women

PURPOSE

Urinary incontinence and fecal incontinence are common disorders in women that negatively impact quality of life. In addition to known health and lifestyle risk factors, genetics may have a role in continence. Identification of genetic variants associated with urinary incontinence and fecal incontinence could result in a better understanding of etiologic pathways, and new interventions and treatments.

MATERIALS AND METHODS

We previously generated genome-wide single nucleotide polymorphism data from Nurses' Health Studies participants. The participants provided longitudinal urinary incontinence and fecal incontinence information via questionnaires. Cases of urinary incontinence (6,120) had at least weekly urinary incontinence reported on a majority of questionnaires (3 or 4 across 12 to 16 years) while controls (4,811) consistently had little to no urinary incontinence reported. We classified cases of urinary incontinence in women into stress (1,809), urgency (1,942) and mixed (2,036) subtypes. Cases of fecal incontinence (4,247) had at least monthly fecal incontinence reported on a majority of questionnaires while controls (11,634) consistently had no fecal incontinence reported. We performed a genome-wide association study for each incontinence outcome.

RESULTS

We identified 8 single nucleotide polymorphisms significantly associated (p <5×10^-8) with urinary incontinence located in 2 loci, chromosomes 8q23.3 and 1p32.2. There were no genome-wide significant findings for the urinary incontinence subtype analyses. However, the significant associations for overall urinary incontinence were stronger for the urgency and mixed subtypes than for stress. While no single nucleotide polymorphism reached genome-wide significance for fecal incontinence, 4 single nucleotide polymorphisms had p <10^-6.

CONCLUSIONS

Few studies have collected genetic data and detailed urinary incontinence and fecal incontinence information. This genome-wide association study provides initial evidence of genetic associations for urinary incontinence and merits further research to replicate our findings and identify additional risk variants.

Role of CYP17 rs743572 Polymorphism in Benign Prostatic Hyperplasia: A Multivariate Integrated Analysis

Objective: Many published studies have investigated the association between CYP17 rs743572 polymorphism and benign prostatic hyperplasia (BPH) susceptibility but have yielded inconsistent results. Hence, we performed this meta-analysis using the multivariate statistic method to address a more precise association.

Methods: Case-control or cohort studies with adequate genotype distribution or minor allele frequency (MAF) were identified by searching the PubMed, Embase, and Web of Science databases up to December, 2018. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association between CYP17 rs743572 polymorphism and BPH susceptibility.

Results: Pooled MAFs of 13 studies were 37% in Caucasians and 56% in Orientals, respectively. Pooled results of 8 studies suggested that CYP17 rs743572 was not associated with the BPH susceptibility in the overall population (OR = 0.98, 95% CI: 0.80–1.20 for A2 vs. A1; OR = 0.99, 95% CI: 0.79–1.25 for A1/A2 vs. A1/A1; OR = 0.97, 95% CI: 0.62–1.53 for A2/A2 vs. A1/A1). Sensitivity analysis showed the results were robust. Subgroup analysis based on ethnicity suggested that, in Orientals, A2 allele carriers had a 28% lower risk of developing BPH compared with A1 allele carriers, and the risk of BPH is 47% lower in A2/A2 genotype carriers compared with A1/A1 genotype carriers. No significant association was observed in Caucasians.

Conclusion: In conclusion, our study indicates a negative association between CYP17 and BPH in Orientals. However, due to limited sample size, the conclusion should be interpreted with caution.

Heritability and genome-wide association study of benign prostatic hyperplasia (BPH) in the eMERGE network

Benign prostatic hyperplasia (BPH) results in a significant public health burden due to the morbidity caused by the disease and many of the available remedies. As much as 70% of men over 70 will develop BPH. Few studies have been conducted to discover the genetic determinants of BPH risk. Understanding the biological basis for this condition may provide necessary insight for development of novel pharmaceutical therapies or risk prediction. We have evaluated SNP-based heritability of BPH in two cohorts and conducted a genome-wide association study (GWAS) of BPH risk using 2,656 cases and 7,763 controls identified from the Electronic Medical Records and Genomics (eMERGE) network. SNP-based heritability estimates suggest that roughly 60% of the phenotypic variation in BPH is accounted for by genetic factors. We used logistic regression to model BPH risk as a function of principal components of ancestry, age, and imputed genotype data, with meta-analysis performed using METAL. The top result was on chromosome 22 in SYN3 at rs2710383 (p-value = 4.6 × 10-7; Odds Ratio = 0.69, 95% confidence interval = 0.55-0.83). Other suggestive signals were near genes GLGC, UNCA13, SORCS1 and between BTBD3 and SPTLC3. We also evaluated genetically-predicted gene expression in prostate tissue. The most significant result was with increasing predicted expression of ETV4 (chr17; p-value = 0.0015). Overexpression of this gene has been associated with poor prognosis in prostate cancer. In conclusion, although there were no genome-wide significant variants identified for BPH susceptibility, we present evidence supporting the heritability of this phenotype, have identified suggestive signals, and evaluated the association between BPH and genetically-predicted gene expression in prostate.

Pathophysiology of Benign Prostatic Hyperplasia and Benign Prostatic Enlargement: A Mini-Review

Benign prostatic hyperplasia (BPH), benign prostatic enlargement (BPE) and lower urinary tract symptoms (LUTS) belong to the most frequent diseases in ageing men. Beyond the 6th decade of life, more than 30% of men suffer from moderate to severe LUTS requiring intervention. The pathophysiology of BPH/BPE is still incompletely understood. The dominant role of the androgen system and the androgen receptor is well defined. Androgen receptors are expressed in BPH tissue in which they are activated by the potent androgen dihydrotestosterone. Synthesis of dihydrotestosterone is under control of the 5α-reductase enzyme, activity of which is antagonized by finasteride and dutasteride. More recently, the impact of prostatic inflammation and metabolic parameters particularly for the development of BPE and LUTS has increasingly been recognized. A better understanding of the pathophysiology is a prerequisite for the development of novel, more effective medical treatment options.

The Epidemiology of Pelvic Floor Disorders and Childbirth: An Update

Using a lifespan model, this article presents new scientific findings regarding risk factors for pelvic floor disorders (PFDs), focusing on the role of childbirth in the development of single or multiple coexisting PFDs. Phase I of the model includes predisposing factors, such as genetic predisposition and race. Phase II includes inciting factors, such as obstetric events. Prolapse, urinary incontinence (UI), and fecal incontinence (FI) are more common among vaginally parous women, although the impact of vaginal delivery on risk of FI is less dramatic than prolapse and UI. Phase III includes intervening factors, such as age and obesity.

Vitamin D and incident urinary incontinence in older adults

BACKGROUND/OBJECTIVES

The aim of this study is to determine whether vitamin D status is associated with incident urinary incontinence (UI) among community-dwelling older adults.

SUBJECTS/METHODS

The University of Alabama at Birmingham Study of Aging is a prospective cohort study of community-dwelling Medicare enrollees. Standardized assessment of UI was conducted using the validated Incontinence Severity Index. The analysis of 25-hydroxyvitamin D [25(OH)D] levels was performed on stored baseline sera. UI was assessed every 6-12 months for up to 42 months. The analyses included multivariable logistic regression and Cox proportional hazard models.

RESULTS

Of 350 participants (175 male, 147 black, mean age 73.6±5.8), 54% (189/350) were vitamin D deficient (25(OH)D <20 ng/ml) and 25% (87/350) were vitamin D insufficient (25(OH)D: 20 ng/ml to <30 ng/ml). Among the 187 subjects with no UI at baseline, 57% (107/187) were vitamin D deficient and 24% (45/187) were vitamin D insufficient. A total of 175 of the 187 subjects had follow-up evaluation for incident UI over 42 months, and incident UI occurred in 37% (65/175). After adjustment, cumulative incident UI at 42 months was associated with baseline vitamin D insufficiency (P=0.03) and demonstrated a trend association with deficiency (P=0.07). There was no association between baseline vitamin D status and the time to incident UI.

CONCLUSIONS

These preliminary results support an association between vitamin D and incident UI in community-dwelling older adults. Future studies may target specific at-risk groups, such as men with BPH or women with pelvic floor disorders for evaluation of the impact of vitamin D supplementation on urinary symptoms.

Urinary Incontinence as a Predictor of Death: A Systematic Review and Meta-Analysis

Background

The association between urinary incontinence (UI) and increased mortality remains controversial. The objective of our study was to evaluate if this association exists.

Methods

We performed a systematic review and meta-analysis of observational studies comparing death rates among patients suffering from UI to those without incontinence. We searched in Medline, Embase and the Cochrane library using specific keywords. Studies exploring the post-stroke period were excluded. Hazard ratios (HR) were pooled using models with random effects. We stratified UI by gender and by UI severity and pooled all models with adjustment for confounding variables.

Results

Thirty-eight studies were retrieved. When compared to non-urinary incontinent participants, UI was associated with an increase in mortality with pooled non adjusted HR of 2.22 (95%CI 1.77–2.78). The risk increased with UI severity: 1.24 (95%CI: 0.79–1.97) for light, 1.71 (95%CI: 1.26–2.31) for moderate, and 2.72 (95%CI: 1.90–3.87) for severe UI respectively. When pooling adjusted measures of association, the resulting HR was 1.27 (95%CI: 1.13–1.42) and increased progressively for light, moderate and severe UI: 1.07 (95%CI: 0.79–1.44), 1.25 (95%CI: 0.99–1.58), and 1.47 (95%CI: 1.03–2.10) respectively. There was no difference between genders.

Conclusion

UI is a predictor of higher mortality in the general and particularly in the geriatric population. The association increases with the severity of UI and persists when pooling models adjusted for confounders. It is unclear if this association is causative or just reflects an impaired general health condition. As in most meta-analyses of observational studies, methodological issues should be considered when interpreting results.

Correlation between prostate volume and single nucleotide polymorphisms implicated in the steroid pathway

OBJECTIVES

A few preliminary studies have suggested a link between some genetics variants and benign prostatic hyperplasia (BPH). Our goal was to study the link between a set of single nucleotide polymorphisms (SNPs) implicated in the steroid pathway and accurate measurement of prostate volume in a cohort of men who underwent radical prostatectomy.

METHODS

Clinical and pathological data including prostate weight were obtained from 611 Caucasian patients with small volume, localized prostate cancer treated by radical prostatectomy. Patients were genotyped for 90 SNPs located inside or nearby genes implicated in the steroid pathway (Sequenom iPLEX). Correlation between prostate weight and genotypes from each SNP was studied by analysis of covariance, adjusted on age and tumor stage. A Bonferroni correction was applied, and the SNPs implicated were then incorporated in a multivariable model.

RESULTS AND LIMITATIONS

Seven SNPs located in or nearby genes implicated in steroid hormone metabolism were significantly associated with prostate volume: HSD17B2 (rs1119933), ESR2 (rs8006145), SULT2B1 (rs279451), NQO1 (rs2917670), ESR1 (rs1569788), GSTP1 (rs1138272), and CYP19A1 (rs17523880). Significant association was maintained after multivariate analysis for four SNPs, indicating their independent association with prostate volume. The power of the association of each SNP with prostate volume was comparable to the effect of age. The strongest associations were found with variants in ESR1, ESR2, HSD17B2, and CYP19A1 genes, indicating a potential role of the estrogen signaling pathway in genesis of BPH.

CONCLUSIONS

Our results are in favor of an implication of estrogen biotransformation and signaling pathways in the pathophysiology of BPH.

Expression of Vitamin D Receptor (VDR) Positively Correlates with Survival of Urothelial Bladder Cancer Patients

Vitamin D3 shows tumoristatic and anticancer effects by acting through the vitamin D receptor (VDR), while hydroxylation of 25-hydroxyvitamin D3 at position 1α by CYP27B1 is an essential step in its activation. The expression of both the VDR and CYP27B1 has been found in many normal and cancer tissues, but there is a lack of information about its expression in human bladder cancers. The aim of the present research was to examine whether the expression of the VDR and CYP27B1 in bladder cancer was related to the prognostic markers and disease outcome. We analyzed VDR and CYP27B1 in samples of tumor and normal tissues obtained from 71 urinary bladder cancer patients. The highest VDR immunostaining was found in normal epithelium and was significantly lower in bladder cancer cells (p < 0.001 with Mann–Whitney U test). VDR expression was lowest in more advanced (pT2b–pT4) (p = 0.005 with Mann–Whitney U test) and metastasizing cancers (p < 0.05 and p = 0.004 with Mann–Whitney U test for nuclear and cytoplasmic VDR immunostaining, respectively). The lack of cytoplasmic and nuclear VDR was also related to shorter overall survival (for cytoplasmic VDR immunolocalization 13.3 vs. 55.3 months of survival, HR = 1.92, p = 0.04 and for nuclear VDR immunostaining 13.5 vs. 55.3 months of survival, HR = 2.47, p = 0.002 with Mantel-Cox test). In cases with the lack of high cytoplasmic VDR staining the non-classic differentiations (NDs) was observed in higher percentage of tumor area. CYP27B1 expression was lower in cancer cells than in normal epithelial cells (p = 0.03 with Mann–Whitney U test), but its expression did not correlate with tumor stage (pT), metastasizing, grade, mitotic activity or overall survival. In conclusion, expression of the VDR and CYP27B1 are deregulated in urothelial bladder cancers. Although our results showing a relationship between the decreased VDR expression and prognostic markers and survival time indicate potential usefulness of VDR as a new indicator of a poorer prognosis, further studies are needed in different patient cohorts by independent groups to validate this hypothesis. We also suggest that vitamin D-based therapies may represent an adjuvant strategy in treatment for bladder cancers expressing VDR.

Update summarising the conclusions of the international consultation on male lower urinary tract symptoms

The International Consultation on Urological Disease have recently published comprehensive conclusions, based on evidence reviewed by eight committees, on aspects of male lower urinary tract symptoms (LUTS). In this review, we summarise the conclusions from four of the committees, namely, the evidence regarding the epidemiology of male LUTS, patient assessment, nocturia and medical management. It is indisputable that with an expanding and ageing global population the prevalence of male LUTS is likely to increase. Therefore symptom prevention and preservation of quality of life (QoL) feature highly in the guidelines. There are now a number of different medical options, proven to lead to significant improvements in symptom scores, flow rate and QoL available to men with LUTS. Meta-analyses have shown the benefits for alpha blockers, antimuscarinics, 5-α reductase and phosphodiesterase-5 inhibitors. High level evidence also exists for combinations of all of the above with alpha blockers and so men with concomitant storage symptoms, prostate volume > 30 mL, PSA > 1.4 or erectile dysfunction may be considered for combination treatment of an alpha blocker with an antimuscarinic, 5-α reductase inhibitor or phosphodiesterase-5 inhibitor respectively. In an era of personalised medicine, appropriate patient selection is likely to provide the key to the most effective clinical management strategy.