Mortality from respiratory diseases associated with opium use: a population-based cohort study.

BACKGROUND: Recent studies have suggested that opium use may increase mortality from cancer and cardiovascular diseases. However, no comprehensive study of opium use and mortality from respiratory diseases has been published. We aimed to study the association between opium use and mortality from respiratory disease using prospectively collected data. METHODS: We used data from the Golestan Cohort Study, a prospective cohort study in northeastern Iran, with detailed, validated data on opium use and several other exposures. A total of 50 045 adults were enrolled from 2004 to 2008, and followed annually until June 2015, with a follow-up success rate of 99%. We used Cox proportional hazard regression models to evaluate the association between opium use and outcomes of interest. RESULTS: During the follow-up period, 331 deaths from respiratory disease were reported (85 due to respiratory malignancies and 246 due to non-malignant aetiologies). Opium use was associated with an increased risk of death from any respiratory disease (adjusted HR 95% CI 3.13 (2.42 to 4.04)). The association was dose-dependent with a HR of 3.84 (2.61 to 5.67) for the highest quintile of cumulative opium use versus never use (Ptrend<0.001). The HRs (95% CI) for the associations between opium use and malignant and non-malignant causes of respiratory mortality were 1.96 (1.18 to 3.25) and 3.71 (2.76 to 4.96), respectively. CONCLUSIONS: Long-term opium use is associated with increased mortality from both malignant and non-malignant respiratory diseases.

Correlation of tissue transglutaminase antibody with duodenal histologic marsh grading.

BACKGROUND Recent guidelines have proposed that there is a correlation between tissue transglutaminase (tTG) antibody titers and degrees of duodenal biopsy, and that duodenal biopsy can be omitted in some patients with high levels of tTG antibody. Using data of registered patients in a gastrointestinal clinic we aimed to assess the correlation between tissue transglutaminase antibody with duodenal histologic Marsh grading in Iranian patients with celiac disease. METHODS We retrospectively reviewed hospital files of registered patients in the gastrointestinal clinic of Firoozgar Hospital, Tehran, Iran. Demographic, laboratory, and histology data of those who had tTG titer and pathology reports of duodenal biopsy based on the modified Marsh classification were extracted and used for the study. RESULTS 159 patients with available tTG titer and pathology reports were enrolled in our study. Mean ±SD of the patients was 35.6±15.2 and 100 (62.9%) of them were women. 133 out of 153 patients had villous atrophy (Marsh IIIa-IIIc). Anemia was the most common sign and bloating, abdominal pain, and diarrhea were the first three common symptoms in these patients. Mean tTG titers was significantly higher in patients graded as Marsh III (p for trend=0.003). Our results showed that tTG titer more than 9 folds higher than the kit's cut-off value was about 97.2% sensitive for Marsh II and more duodenal damage. CONCLUSION There was a correlation between tTG titers and degrees of duodenal damage in patients with celiac disease. Duodenal biopsy is not always necessary for diagnosing celiac disease and when tTG level is more than 9 folds higher than the manufacture's recommended cut-off value it can be avoided. Meanwhile small intestinal biopsy should always be considered in case of high clinical suspicion, regardless of the results of serologic testing.

Is opium a real risk factor for esophageal cancer or just a methodological artifact? Hospital and neighborhood controls in case-control studies.

BACKGROUND: Control selection is a major challenge in epidemiologic case-control studies. The aim of our study was to evaluate using hospital versus neighborhood control groups in studying risk factors of esophageal squamous cell carcinoma (ESCC). METHODOLOGY/PRINCIPAL FINDINGS: We compared the results of two different case-control studies of ESCC conducted in the same region by a single research group. Case definition and enrollment were the same in the two studies, but control selection differed. In the first study, we selected two age- and sex-matched controls from inpatient subjects in hospitals, while for the second we selected two age- and sex-matched controls from each subject's neighborhood of residence. We used the test of heterogeneity to compare the results of the two studies. We found no significant differences in exposure data for tobacco-related variables such as cigarette smoking, chewing Nass (a tobacco product) and hookah (water pipe) usage, but the frequency of opium usage was significantly different between hospital and neighborhood controls. Consequently, the inference drawn for the association between ESCC and tobacco use did not differ between the studies, but it did for opium use. In the study using neighborhood controls, opium use was associated with a significantly increased risk of ESCC (adjusted OR 1.77, 95% CI 1.17-2.68), while in the study using hospital controls, this was not the case (OR 1.09, 95% CI 0.63-1.87). Comparing the prevalence of opium consumption in the two control groups and a cohort enrolled from the same geographic area suggested that the neighborhood controls were more representative of the study base population for this exposure. CONCLUSIONS/SIGNIFICANCE: Hospital and neighborhood controls did not lead us to the same conclusion for a major hypothesized risk factor for ESCC in this population. Our results show that control group selection is critical in drawing appropriate conclusions in observational studies.

Prevalence of chronic kidney disease and its associated risk factors: the first report from Iran using both microalbuminuria and urine sediment.

BACKGROUND: The incidence of major risk factors of chronic kidney disease (CKD) in the world is on the rise, and it is expected that this incidence and prevalence, particularly in developing countries, will continue to increase. Using data on urinary sediment and microalbuminuria, we aimed to estimate the prevalence of CKD in northeast Iran. METHODS: In a cross-sectional study, the prevalence of CKD in a sample of 1557 regionally representative people, aged ≥ 18 years, was analyzed. CKD was determined based on glomerular filtration rate (GFR) and microalbuminuria. Life style data, urine and blood samples were collected. Urine samples without any proteinuria in the initial dipstick test were checked for qualitative microalbuminuria. If the latter was positive, quantitative microalbuminuria was evaluated. RESULTS: 1557 subjects with a mean age of 56.76 ± 12.04 years were enrolled in this study. Based on the modification of diet in renal disease (MDRD) equation, 137 subjects (8.89%) were categorized as CKD stages III-V. Based on urine abnormalities, the prevalence of combined CKD stages I and II was 10.63%, and based on macro- and microalbuminuria it was 14.53%. The prevalence of CKD was significantly associated with sex, age, marital status, education, diabetes mellitus (DM), hypertension (HTN), ischemic heart disease (IHD), waist to hip ratio, myocardial infarction (MI), and cerebrovascular accident (CVA). CONCLUSION: CKD and its main risk factors are common and represent a definite health threat in this region of Iran. Using and standardizing less expensive screening tests in low resource countries could be a good alternative that may improve the outcome through early detection of CKD.