Background The burden of inflammatory bowel disease (IBD) is rising globally, with substantial variation in levels and trends of disease in different countries and regions. Understanding these geographical differences is crucial for formulating effective strategies for preventing and treating IBD. We report the prevalence, mortality, and overall burden of IBD in 195 countries and territories between 1990 and 2017, based on data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017.Methods We modelled mortality due to IBD using a standard Cause of Death Ensemble model including data mainly from vital registrations. To estimate the non-fatal burden, we used data presented in primary studies, hospital discharges, and claims data, and used DisMod-MR 2.1, a Bayesian meta-regression tool, to ensure consistency between measures. Mortality, prevalence, years of life lost (YLLs) due to premature death, years lived with disability (YLDs), and disability-adjusted life-years (DALYs) were estimated. All of the estimates were reported as numbers and rates per 100 000 population, with 95% uncertainty intervals (UI). Findings In 2017, there were 6•8 million (95% UI 6•4-7•3) cases of IBD globally. The age-standardised prevalence rate increased from 79•5 (75•9-83•5) per 100 000 population in 1990 to 84•3 (79•2-89•9) per 100 000 population in 2017. The age-standardised death rate decreased from 0•61 (0•55-0•69) per 100 000 population in 1990 to 0•51 (0•42-0•54) per 100 000 population in 2017. At the GBD regional level, the highest age-standardised prevalence rate in 2017 occurred in high-income North America (422•0 [398•7-446•1] per 100 000) and the lowest agestandardised prevalence rates were observed in the Caribbean (6•7 [6•3-7•2] per 100 000 population). High Sociodemographic Index (SDI) locations had the highest age-standardised prevalence rate, while low SDI regions had the lowest age-standardised prevalence rate. At the national level, the USA had the highest age-standardised prevalence rate (464•5 [438•6-490•9] per 100 000 population), followed by the UK (449•6 [420•6-481•6] per 100 000). Vanuatu had the highest age-standardised death rate in 2017 (1•8 [0•8-3•2] per 100 000 population) and Singapore had the lowest (0•08 [0•06-0•14] per 100 000 population). The total YLDs attributed to IBD almost doubled over the study period, from 0•56 million (0•39-0•77) in 1990 to 1•02 million (0•71-1•38) in 2017. The agestandardised rate of DALYs decreased from 26•5 (21•0-33•0) per 100 000 population in 1990 to 23•2 (19•1-27•8) per 100 000 population in 2017.Interpretation The prevalence of IBD increased substantially in many regions from 1990 to 2017, which might pose a substantial social and economic burden on governments and health systems in the coming years. Our findings can be useful for policy makers developing strategies to tackle IBD, including the education of specialised personnel to address the burden of this complex disease.Funding Bill & Melinda Gates Foundation.

Background There is considerable variation in hypertension prevalence and awareness, and their correlates, across different geographic locations and ethnic groups. We performed this cross-sectional analysis on data from the Golestan Cohort Study (GCS). Methods Enrollment in this study occurred in 2004–2008, and included 50,045 healthy subjects from Golestan Province in northeastern Iran. Hypertension was defined as a systolic blood pressure (SBP) ≥140, a diastolic blood pressure (DBP) ≥90, a prior diagnosis of hypertension, or the use of antihypertensive drugs. Potential correlates of hypertension and its awareness were analyzed by logistic regression adjusted for sex, age, BMI, place of residence, literacy, ethnicity, physical activity, smoking, black and green tea consumption and wealth score. Results Of the total cohort participants, 21,350 (42.7%) were hypertensive. Age-standardized prevalence of hypertension, using the 2001 WHO standard world population, was 41.8% (95%CI: 38.3%–45.2%). Hypertension was directly associated with female sex, increased BMI, Turkmen ethnicity, and lack of physical activity, and inversely associated with drinking black tea and wealth score. Among hypertensive subjects, 46.2% were aware of their disease, 17.6% were receiving antihypertensive medication, and 32.1% of the treated subjects had controlled hypertension. Hypertension awareness was greater among women, the elderly, overweight and obese subjects, and those with a higher wealth score. Conclusions Hypertension is highly prevalent in rural Iran, many of the affected individuals are unaware of their disease, and the rate of control by antihypertensive medications is low. Increasing hypertension awareness and access to health services, especially among less privileged residents are recommended.

Background Opium use, particularly in low doses, is a common practice among adults in northeastern Iran. We aimed to investigate the association between opium use and subsequent mortality from disorders of the digestive tract. Methods We used data from the Golestan Cohort Study (GCS), 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 during a four-year period (2004–2008) and followed annually until December 2012, 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 8,487 (17%) participants reported opium use, with a mean duration of 12.7 years. During the follow-up period 474 deaths from digestive diseases were reported (387 due to gastrointestinal cancers and 87 due to nonmalignant etiologies). Opium use was associated with an increased risk of death from any digestive disease (adjusted hazard ratio (HR) = 1.55, 95% CI 1.24 – 1.93). The association was dose-dependent, with a HR of 2.21 (1.57–3.31) for the highest quintile of cumulative opium use vs. no use (Ptrend = 0.037). The hazard ratios (95% CI) for the associations between opium use and malignant and nonmalignant causes of digestive mortality were 1.38 (1.07 – 1.76) and 2.60 (1.57 – 4.31), respectively. Increased risks were seen both for smoking opium and for ingestion of opium. Conclusion Long-term opium use, even in low doses, is associated with increased risk of death from both malignant and nonmalignant digestive diseases.