Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder. Despite its significant morbidities and mortality, the majority of patients with OSA remain undiagnosed. The epidemiology of OSA is well studied in Western countries, while there is scarce information on its epidemiology in other countries. We examined the prevalence of high-risk for OSA in a large urban region of Tehran, Iran. We randomly selected 4021 individuals above 18 years in clusters from different districts of Tehran and surveyed them using the Stop-Bang questionnaire. The questionnaire also incorporated the demographic characteristics, education level, history of coronary artery disease and diabetes, and women’s menopausal status. A score of 3 or higher on the Stop-Bang questionnaire indicated the high risk of OSA. The study population consisted of 2075 (51.6%) females and 1946 (48.4%) males, with the mean age of 40.88 years (SD, 15.4) and mean body mass index (BMI) of 26.18 kg/m2 (SD, 4.43). Overall, 51.4% of males and 26.5% of females (total, 1513; 38.6%) were classified in the high-risk group, according to the Stop-Bang questionnaire. The risk of OSA was directly correlated with BMI, advanced age, and history of cardiovascular diseases and diabetes. According to the Stop-Bang questionnaire, almost 1 out of every 3 individuals was classified in the high-risk group for OSA. Considering the significant morbidity and mortality of this disorder, it is considered a major health problem. Therefore, further detailed studies with confirmatory tests are recommended in order to plan strategies for the diagnosis, treatment, and rehabilitation of these patients.

Background: Idiopathic pulmonary arterial hypertension (IPAH) is a fatal illness. Despite many improvements in the treatment of these patients, there is no unique prognostic variable available to track these patients. The aim of this study was to evaluate the association between fractional exhaled nitric oxide (FeNO) levels, as a noninvasive biomarker, with disease severity and treatment outcome. Methods: Thirty-six patients (29 women and 7 men, mean age 38.4 ± 11.3 years) with IPAH referred to the outpatient’s clinic of Masih Daneshvari Hospital, Tehran, Iran, were enrolled into this pilot observational study. Echocardiography, six-minute walking test (6MWT), FeNO, brain natriuretic peptide (BNP) levels and the functional class of patients was assessed before patients started treatment. Assessments were repeated after three months. 30 healthy non-IPAH subjects were recruited as control subjects. Results: There was no significant difference in FeNO levels at baseline between patients with IPAH and subjects in the control group. There was also no significant increase in FeNO levels during the three months of treatment and levels did not correlate with other disease measures. In contrast, other markers of disease severity were correlated with treatment effect over the three months. Conclusion: FeNO levels are a poor non-invasive measure of IPAH severity and of treatment response in patients in this pilot study.

Background: Admission to the ICU (intensive care unit) is frequently complicated by early AKI (acute kidney injury). The development of AKI following cardiac surgery is particularly associated with increased mortality and morbidity. According to AKIN (acute kidney injury network) criteria, UO (urinary output) is a predictor for AKI. Objectives: The goal of this study was to determine the effects of some AKI risk factors on AKI and also to investigate changes in UO as a predictor of AKI using joint modeling. Patients and Methods: In a retrospective study, 300 cardiac-operated patients, who had been admitted over a period of three years, were selected according to the consecutive sample selection method, using the ICU at Masih Daneshvari Hospital in Iran as a referral center. The random mixed effect model and the survival model were used to investigate UO changes and estimate the effect of UO and other risk factors on the hazard rate of AKI in a joint analysis. Results: AKI occurred in 38.0% of patients. A significant decrease of UO occurred more often in female and infected patients, as well as those with a low DBP (diastolic blood pressure). The survival model showed that the risk of AKI in females, older patients and patients with low DBP, lower UO and with infection was higher (P = 0.001). Using joint modeling, the association parameter between the risk of AKI and UO was estimated (-0.3, P = 0.002). Conclusions: Where there is a relationship between two longitudinal and survival responses, joint modeling can estimate it. Keywords: Acute Kidney Injury; Joint Models; Risk Factor; Urinary Output; Cardiac Surgery