Prevalence of the overactive bladder among Iranian women based on the International Continence Society definition: a population-based study

There is a continuing debate on the accurate prevalence estimates of overactive bladder (OAB) among different ethnicities and regions. The aims of our study were to determine the prevalence of OAB, associated risk factors, and the impact of OAB on the quality of life and sexual function of Iranian women. A total of 8748 women between 15 and 55 years of age enrolled in this cross-sectional study. The definition of the 2002 International Continence Society (ICS) was applied to assess the prevalence of OAB. All participants underwent a detailed history and physical examination that included an evaluation of quality of life, coping strategies and treatment-seeking behavior, laboratory tests, urinalysis and current or previous therapy. The degree of bother was quantified using s visual analog scale (VAS). The overall prevalence of OAB was found to be 18.2% and increased with age from 10.9% in adults aged 15–29 years to 26.2% in those aged >50 years old (test for trend, P = 0.001). A negative impact of OAB on sexual function was reported by 72.3% of the women. Frequency was the most commonly reported symptom (67% of women), followed by urgency (54%). Subjects with OAB had a higher prevalence of anxiety (28.2 vs. 8.8%; P = 0.001), depression (38.2 vs. 18.2%; P = 0.02) and tiredness (16.4 vs. 2.7%; P = 0.001), and they reported significant impairment in carrying out household chores (P = 0.01), physical activities (P = 0.01) and work-related activities (P = 0.01) as well as negative effects on education (P = 0.02), sleep (P = 0.001), relationships (P = 0.001) and annual income (P = 0.01). The prevalence of OAB in Iranian women is higher than that reported in many previous studies in developed and developing countries. Our results reveal that OAB is a highly prevalent condition among Iranian women and that is has a serious impact on quality of life and sexual function. Mohammad Reza Safarinejad, Vice-Chancellor for Education and Research, Urology and Nephrology Research Center, Associate Professor of Urology, Director Department of Urology, Associate Editor of Urology Journal.     

Clinical utility of electrodiagnostic studies in the inpatient setting

Although nerve conduction studies/electromyograms are often requested to evaluate hospitalized patients (inpatients) with suspected neuromuscular diseases, their clinical utility has not been studied. They can be technically challenging, especially in intensive care units. We studied the contribution of inpatient electromyograms (IP‐EMGs) to the management of patients with suspected neuromuscular disorders. A total of 103 IP‐EMGs in 98 patients were analyzed. IP‐EMGs confirmed the clinical diagnosis in 53.3% and provided a new, clinically relevant diagnosis in 12.6%. IP‐EMGs revealed only an incidental diagnosis in 14.5%, were inconclusive in 16.5%, and were normal in 3%. In over a quarter of patients, IP‐EMGs assisted in planning further diagnostic evaluation or treatment. Although IP‐EMGs most often only confirm already suspected diagnoses, in a substantial minority of patients they lead to the identification of clinically unsuspected, significant diagnoses that alter subsequent clinical care. Muscle Nerve 40: 195–199, 2009     

Factors influencing the acceptance of changes in antiretroviral therapy among HIV-1-infected patients

Physicians routinely consider modifying antiretroviral therapy (ART) regimen for their patients with HIV. Little is known about the factors associated with patients' willingness to accept providers' recommended ART changes. This multicenter prospective observational study examined factors associated with willingness to accept ART changes recommended by their providers among HIV-infected adults from six urban outpatient HIV clinics. Patients were surveyed using the Patient Attitudes about Altering Antiretroviral Therapy Survey questionnaire (PAAARTS). Factors associated with willingness to accept ART changes were assessed using a multivariate generalized estimating equation (GEE) model to account for correlated responses. The Classification and Regression Trees (CART) analysis was also performed to determine subgroups of patients with higher acceptance of change. 216 of 289 patients (75%) definitely accepted recommended changes. Odds for acceptance were 3.2, 2.3, and 2.8 times higher for patients with higher attitudes and beliefs about ART (p < 0.01; 95% confidence interval [CI] = 1.59, 6.52), patients who rated their provider's care as excellent (p < 0.05; 95% CI = 1.07, 4.78), and non-Hispanic patients (p < 0.05; 95% CI 1.03, 7.57), respectively. CART analysis showed similar results and identified that when patients had less positive attitude about ART, acceptance rates were higher for non-Hispanic patients with higher assessments of their patient-provider communication. While most patients accepted providers' recommendation for ART changes, this willingness was influenced by both patients' attitudes and beliefs about ART and their assessment of either the effectiveness of patient-provider communication or their rating of providers' care. ART acceptance rates among Hispanic patients were lower.     

The influence of aging on pharyngeal collapsibility during sleep

BACKGROUND: Aging increases vulnerability to obstructive sleep apnea (OSA), but the underlying mechanisms remain unclear. Recent data in awake healthy volunteers show a decrease in the genioglossus negative pressure reflex and anatomic compromise with increasing age, suggesting an age-related predisposition to pharyngeal collapse. However, aging effects on pharyngeal collapsibility have not been studied extensively during sleep. We tested the hypotheses that upper airway closing pressure (PCLOSE) and the increase in pharyngeal resistance during sleep (primary outcomes) as well as measures of arousal threshold (secondary outcomes) increase with age. METHODS: We studied 21 healthy individuals (8 women [mean (+/- SD) age, 36 +/- 18 years] and 13 men [mean age, 41 +/- 23 years]) who were between 18 and 75 years of age. During overnight polysomnography, we measured nasal pressure (PMASK) and epiglottic pressure (Pepi) during stage 2 sleep before and after airway occlusion (external valve) until arousal. PCLOSE was defined as the pressure at which PMASK plateaued despite further decreases in PEPI. RESULTS: Increasing age was correlated with both pharyngeal collapsibility ([PCLOSE] r = 0.69; p < 0.01) and an increase in pharyngeal resistance during sleep (r = 0.56; p < 0.01) independent of body mass index (BMI) and gender. There was no evidence for an effect of age on arousal threshold after airway occlusion during stage 2 sleep. CONCLUSIONS: Older age is associated with increased pharyngeal airway collapsibility during sleep independent of gender and BMI. These data may at least partially explain the mechanisms underlying the predisposition for pharyngeal collapse in the elderly.     

Genetic susceptibility of methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms with risk for bladder transitional cell carcinoma in men

We performed a case-control study of 158 bladder transitional cell carcinoma (TCC) cases and 316 controls to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T, A1298G, and G1793A polymorphisms and bladder cancer susceptibility by polymerase chain reaction restriction fragment length polymorphism (PCR-RLFP) technique. The controls were frequency-matched to the cases by age (± 5 years), ethnicity, and smoking status. We also measured serum levels of total homocysteine (tHcy), folate, and vitamin B12. It was found that the 1298AC (odds ratio, OR = 3.74; 95% confidence interval, CI = 2.34-5.47; P = 0.001) and 1298CC (OR = 3.46, 95% CI = 2.37-5.52; P = 0.001) genotypes of MTHFR A1298C were significantly associated with increased risk of bladder TCC. The MTHFR C677T and G1793A polymorphisms were not associated with bladder TCC. After stratification for grade and stage, we observed that the 677TT (OR = 4.47, 95% CI = 2.74-6.72; P = 0.001) and MTHFR 1298CC (OR = 4.78, 95% CI = 2.82-6.89; P = 0.001) genotypes of MTHFR were associated with increased risk of muscle-invasive bladder TCC. We also found that the MTHFR 677CT+1298AA genotypes were associated with an approximately 70% reduction in risk of bladder cancer (OR = 0.31; 95% CI = 0.15-0.68) compared to the combined referent genotype. There were 8 haplotypes and 16 haplotype genotypes based on these three variants. When we used the haplotypes and assumed that the 677T, 1298C, and 1793G alleles were risk alleles, the adjusted odds ratios increased as the number of risk alleles increased: 1.00 for 0-1 variant, 1.88 (1.4-2.7) for any two risk alleles and 2.07 (1.6-2.8) for any three risk alleles. Serum tHcy levels were significantly higher in carriers of the 677T, 1298C, and 1793G alleles compared to noncarriers (all P < 0.01). There was no significant correlation between serum levels of tHcy and folate and bladder cancer risk. Further studies in larger samples size and different ethnicity are required to confirm our findings.     

Infertility among couples in a population-based study in Iran: prevalence and associated risk factors

To explore the prevalence and risk factors of infertility in Iran, a total of 12 285 ever-married women aged 15-50 years old and their husbands (if available) were interviewed by 82 female general practitioners and answered a self-administered questionnaire on several aspects of infertility. They were identified from the national population in 30 counties, and invited to a confidential interview. Data were obtained about their age, education, marital status, toxic habits, medical history, disabilities and illnesses, help-seeking, economy, ethnicity, geographic location, contraceptive use and age at which they had first intercourse. This study used the definition of childlessness proposed by World Health Organization: 'the woman has never conceived despite cohabitation and exposure to pregnancy for a period of 2 years'. The overall prevalence of infertility was 8% (95% CI: 3.2-15.0). The weighted national estimate of primary infertility was 4.6% (95% CI: 3.6-5.2). There was a pronounced regional pattern in the levels of primary infertility. The primary infertility increased significantly from 2.6 to 4.3 to 5.5% for the 1985-1989, 1990-1994 and 1995-2000 marriage cohorts. The prevalence of secondary infertility was 3.4% (95% CI: 2.4-5.1). Overall the prevalence of infertility falls within a relatively wide range being high in the Southern counties, and low in the Northern counties. The probability of first pregnancy at the end of 2 years of marriage was 0.78 for all ever-married women. The prevalence of infertility increased with age (linear chi-square 198.012, 1 d.f., p = 0.01). The age pattern of infertility also varies quite markedly across the counties analysed. No effect of race was detected; neither the intercept (analysis of covariance p = 0.36) nor the slope of the age relationship was influenced by race (analysis of covariance p = 0.41). Infertility were observed as significantly higher in the presence of history of tubo-ovarian surgery [odds ratio (OR): 1.43; 95% CI: 1.28-2.23; p = 0.01], salpingitis (OR: 2.34; 95% CI: 1.31-4.3; p = 0.016), ectopic pregnancy (OR: 2.45; 95% CI: 1.90-3.44; p = 0.04), varicocele (OR: 2.85; 95% CI: 1.61-5.20; p = 0.01) and cryptorchidism (OR: 3.81; 95% CI: 2.51-4.28; p = 0.031). This study provides a quantitative estimate of the prevalence and main risk factors for infertility in Iranian couples. Yet, further studies on the cause of primary and secondary infertility and geographical variations in the incidence and prevalence of infertility in Iran are needed.     

Deoxymyoglobin is a nitrite reductase that generates nitric oxide and regulates mitochondrial respiration

Previous studies have revealed a novel interaction between deoxyhemoglobin and nitrite to generate nitric oxide (NO) in blood. It has been proposed that nitrite acts as an endocrine reservoir of NO and contributes to hypoxic vasodilation and signaling. Here, we characterize the nitrite reductase activity of deoxymyoglobin, which reduces nitrite approximately 36 times faster than deoxyhemoglobin because of its lower heme redox potential. We hypothesize that physiologically this reaction releases NO in proximity to mitochondria and regulates respiration through cytochrome c oxidase. Spectrophotometric and chemiluminescent measurements show that the deoxymyoglobin-nitrite reaction produces NO in a second order reaction that is dependent on deoxymyoglobin, nitrite and proton concentration, with a bimolecular rate constant of 12.4 mol/L(-1)s(-1) (pH 7.4, 37 degrees C). Because the IC(50) for NO-dependent inhibition of mitochondrial respiration is approximately 100 nmol/L at physiological oxygen tensions (5 to 10 mumol/L); we tested whether the myoglobin-dependent reduction of nitrite could inhibit respiration. Indeed, the addition of deoxymyoglobin and nitrite to isolated rat heart and liver mitochondria resulted in the inhibition of respiration, while myoglobin or nitrite alone had no effect. The addition of nitrite to rat heart homogenate containing both myoglobin and mitochondria resulted in NO generation and inhibition of respiration; these effects were blocked by myoglobin oxidation with ferricyanide but not by the xanthine oxidoreductase inhibitor allopurinol. These data expand on the paradigm that heme-globins conserve and generate NO via nitrite reduction along physiological oxygen gradients, and further demonstrate that NO generation from nitrite reduction can escape heme autocapture to regulate NO-dependent signaling.     

Prevalence of benign prostatic hyperplasia in a population-based study in Iranian men 40 years old or older

Epidemiology of benign prostatic hyperplasia (BPH) is incompletely understood. The following study was done to estimate the prevalence of BPH according to obstructive and irritative symptoms of prostate obstruction determined by uroflowmetry and prostate size. In a cross-sectional study a total of 8,466 men aged 40 or older were interviewed by 74 general practitioners and answered the International Prostate Symptom Score (I-PSS) questionnaire. The subjects were randomly identified from 30 counties of Iran. They were invited to have a digital rectal examination (DRE), serum total prostate-specific antigen (tPSA) assay, abdominal ultrasonography to measure prostate size and measurement of maximum urinary flow rate (Qmax). Data on medical history, toxic habits, and current use of medications were obtained. Of the men interviewed, the prevalence of BPH, defined as I-PSS greater than 7, maximum flow less than 15 ml/s and prostate size greater than 30 gm, was 23.8%. The prevalence increased with age, from 1.2% in men 40–49 to 36% in those >70 years (tested for trend, P = 0.001). A positive association was found between BPH and body mass index (BMI) (P = 0.04), height (P = 0.03), diabetes mellitus (P = 0.04), increased total energy intake (P = 0.02), age-adjusted levels of total PSA (P = 0.02), heart disease (P = 0.03), and marital status (P = 0.01). The prevalence of BPH is relatively high in Iran. The provided bothersome due to BPH did not correlate to symptom severity and should be considered independently in clinical decision-making.