Can temperature explain the latitudinal gradient of ulcerative colitis? Cohort of Norway

Short-term effects of ambient temperature on acute exacerbation of inflammatory bowel disease: A nationwide case-crossover study with external validation

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disorder characterized by chronic and relapsing manifestations. Several environmental factors are known as triggers for exacerbation of IBD. However, an association between exacerbation of IBD and ambient temperature is uncertain. This study aimed to estimate the risk of acute exacerbation of IBD due to ambient temperature. We performed a bidirectional case-crossover study using a nationwide claim data from South Korea. The external validation was conducted with a large prospective cohort in the United Kingdom. We confirmed significant associations between acute exacerbation of IBD and the short-term ambient temperature changes toward severe temperatures, in the cold weather (-19.4°C-4.3°C) (odd ratio [OR] = 1.13, 95% confidence interval [CI]: 1.13-1.14) and in the hot weather (21.3°C-33.5°C) (OR = 1.16, 95% CI: 1.15-1.17). However, the association was not significant in the moderate weather (4.3°C-21.3°C). The external validation suggested consistent results with additional elevation of acute exacerbation risk in the colder weather (-13.4°C to 2.6°C) (OR = 1.90, 95% CI: 1.62-2.22) and in the hotter weather (15.7°C-28.4°C) (OR = 1.41, 95% CI: 1.32-1.51). We observed and validated that the short-term ambient temperature changes were associated with acute exacerbation of IBD in the cold and hot weathers. Our findings provide evidence that temperature changes are associated with the acute exacerbation of IBD.

The global, regional, and national burden of inflammatory bowel diseases, 1990-2019: A systematic analysis for the global burden of disease study 2019

BACKGROUND

In recent years, the global epidemiology of inflammatory bowel disease (IBD) has changed rapidly.

AIMS

We described the updated global IBD epidemiology results based on the 2019 Global Burden of Diseases, Injuries, and Risk Factors Study (GBD).

METHODS

We estimated the prevalence rate, death rate, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) from GBD 2019 in 195 countries and territories between 1990 and 2019.

RESULTS

The crude prevalence of IBD increased by 47% in 2019 globally. Accordingly, the age-standardized prevalence rate showed 19% decrease. The age-standardized death rates, YLDs, YLLs, and DALYs of IBD in 2019 decreased compared to those in 1990. The annual percentage change in age-standardized prevalence rate decreased most in United States and increased in East Asia and high-income Asia Pacific from 1990 to 2019. Continents with high socioeconomic index (SDI) had higher age-standardized prevalence rates compared to continents with low SDI. The 2019 age-standardized prevalence rate of high latitudes was higher than that of low latitudes in Asia, Europe, and North America.

CONCLUSION

The observed trends and geographic variations in IBD documented in the 2019 GBD study will aid policymakers in policy, research, and investment development.

Prevention of ulcerative colitis by Huangqin decoction: reducing the intestinal epithelial cell apoptosis rate through the IFN-γ/JAK/ETS signalling pathway

CONTEXT

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease that is closely related to inflammation and apoptosis. The traditional Chinese medicine compound preparation Huangqin decoction (HQD) has been widely used in the clinical treatment of UC, but the specific mechanism of its function is still inconclusive.

OBJECTIVE

To explore the pathogenesis of UC based on the IFN-γ/JAK/ETS signalling pathway, and to clarify the biological mechanism of HQD.

MATERIALS AND METHODS

Forty 8-week-old male C57BL/6 mice were randomly divided into four groups: normal control, model, model + salazosulfapyridine group (500 mg/kg, p.o., pd) and model + HQD (9.1 g/kg, p.o., pd). Using Dextran sulphate sodium (DSS) salt (2.5%, p.o.)+high-fat diet + hot and humid environment to build a mouse model of UC. One month later, the changes of colon morphology, serum inflammatory factors, intestinal epithelial cell apoptosis and IFN-γ/JAK/ETS signalling pathway related protein changes in mice were observed.

RESULTS

Compared with the model group, HQD significantly reduced the pathological score of the model mice's colon (2.60 ± 0.25 vs. 4.80 ± 0.37), and reduced the serum IFN-γ (200.30 ± 8.45 vs. 413.80 ± 6.97) and other inflammatory factors, and reduced intestinal epithelial cell apoptosis (24.85 ± 4.87 vs. 214.90 ± 39.21). In terms of mechanism, HQD down-regulated IFN-γ/JAK/ETS signalling pathway related proteins in colon tissue of UC model mice.

CONCLUSIONS

These data indicate that HQD can improve UC by reducing intestinal inflammation and apoptosis, providing experimental evidence for the wide application of HQD in clinical practice of UC.

Incidence and Prevalence of Inflammatory Bowel Disease across Asia

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), are chronic inflammatory disorders of the gastrointestinal tract caused by interactions between genetic, environmental, immunological, and microbial factors. While the incidence and prevalence of IBD in Asian populations were relatively lower than those in Western countries, they appear to be gradually increasing. A Westernized diet, high socioeconomic status, improvement of hygiene, and development of vaccination could affect the increases in IBD incidence and prevalence in Asian countries. This review describes the latest trends in the incidence and prevalence of IBD in Asia. Studying the epidemiology of IBD in Asia may unravel the etiopathogenesis of and risk factors for IBD.

Global associations of national economic wealth are more robust with inflammatory bowel diseases than with obesity

The inflammatory bowel diseases consisting of Crohn's and ulcerative colitis have expanded into previously low incidence areas of the world. The spread follows the relatively recent pandemic of global obesity. Pathological relations have been proposed between these two diseases. Both inflammatory bowel diseases and obesity originated in wealthier western societies marked by high gross domestic product per capita. The pathogenic influence of national wealth on the inflammatory bowel diseases has been recognized but are less clear with obesity. Parallel correlations of national wealth with obesity would further strengthen relations between these two diseases. Alternatively, diverging relations could suggest that obesity is less dependent on wealth. As such it would supports another earlier hypothesis that obesity depends on adoption of western diet which precedes national acquisition of wealth. Previously ecological modifiers of global disease patterns, including latitude and lactose digestion status have shown different influences on IBD compared with obesity. We evaluate. the influence of the Gross Domestic Product on these two diseases taking into consideration the former's relationship with ecological markers. Patterns of correlations could suggest contributing mechanisms how these ecological parameters influence some disease distributions. The literature and internet were searched for national rates of obesity, inflammatory bowel diseases, national gross domestic product per capita and national lactase distribution rates. National average latitudes were calculated previously. Pearson correlations were used to compare variables in three regions; global, European and Asian theaters. SAS statistical package was used and statistical significance was accepted at p < 0.05. Globally and in Europe correlations of gross domestic product were moderate and significant r = 0.55 and r = 0.6 respectively with Crohn's disease but weaker with ulcerative colitis. The results were negligible in Asia. Obesity was weakly correlated with gross domestic product globally r = 0.32 and negligible in Europe and Asia. In addition, gross domestic product was moderately correlated with latitude r = 0.6, and inversely with lactase non persistence r = -0.6 both globally and in Europe. This relationship is similar to that with inflammatory bowel diseases, but less related to obesity. Overall results suggest unequal effect of national wealth and industrialization on obesity and inflammatory bowel diseases. It has been suggested that western type diet precedes full industrialization and this could promote obesity.

Long-term effects of latitude, ambient temperature, and ultraviolet radiation on the incidence of multiple sclerosis in two cohorts of US women

Supplemental Digital Content is available in the text.

Differences in multiple sclerosis (MS) risk by latitude have been observed worldwide; however, the exposures driving these associations are unknown. Ultraviolet radiation (UV) has been explored as a risk factor, and ambient temperature has been correlated with disease progression. However, no study has examined the impact of all three exposures. We examined the association between these exposures and incidence of MS within two nationwide prospective cohorts of women, the Nurses’ Health Study (NHS) and Nurses’ Health Study II (NHSII).

Changing Patterns of Relationships Between Geographic Markers and IBD: Possible Intrusion of Obesity

Background

Latitude and lactase digestion status influence incidence and prevalence rates of some noncommunicable diseases. Latitudinal correlations helped define beneficial roles of vitamin D in many diseases like inflammatory bowel disease (IBD). In view of recent global expansion of IBD and population migrations, we reexamine relations with these markers. As these changes also paralleled the pandemic of obesity, we explore possible interactions with IBD.

Methods

We undertook a literature review to compare rates of obesity, Crohn's disease and ulcerative colitis with the geographic markers of lactase digestion status, average population-weighted national latitude, and national yearly sunshine exposure. Pearson correlations were used throughout to determine r correlation factors. Statistical significance was accepted at P <0.05 using 2-tailed tests.

Results

Forty-seven countries were matched with various data sets that could be analyzed (range of availability was 49%-85%). While global correlations of IBD with latitude and lactase status remain similar to previous analyses, in Europe and Asia, outcomes were different. Global outcome contains a statistical paradox related to combining countries from Europe and Asia. Obesity showed moderate global correlations with IBD but weak and negligible correlations in Europe and Asia. There was also a weak global correlation with latitude.

Conclusions

It is suggested that global correlations point to parallel geographic spread of IBD and obesity. The lack of latitudinal relations with obesity suggests reduced vitamin D effect. The paradox supports epidemiological differences in western and eastern IBD. Obesity combined with IBD may contribute to different relations, partly due to variable vitamin D effects.

Inflammatory bowel disease incidence, prevalence and 12-month initial disease course in Tasmania, Australia

BACKGROUND

High inflammatory bowel disease (IBD) rates have been reported in Australasia, but no state-wide studies have yet been performed.

AIM

This study estimates the 1-year incidence and point prevalence of IBD in the state of Tasmania, Australia. It also reports clinical outcomes after 12 months of diagnosis in an incident cohort.

METHODS

A prospective, population-based study was performed collecting prevalent and incident state-wide cases from 1 June 2013 to 31 May 2014. Case data were identified from specialist doctors, pathology databases and hospital records. Age-standardised rates (ASR) were calculated based on World Health Organization 2000 standard population characteristics. Incident cases were followed up 12 months after diagnosis.

RESULTS

There were 1719 prevalent cases: ASR for IBD, Crohn disease (CD), ulcerative colitis (UC) and inflammatory bowel disease unclassified (IBDU) prevalence rates were 303.9, 165.5, 131.4 and 6.9 per 100 000 respectively. Prevalent CD cases were younger, with greater immunomodulator/biological use and bowel resections. There were 149 incident cases: ASR for IBD, CD, UC and IBDU incidence were 29.5, 15.4, 12.4 and 1.7 per 100 000 respectively. Incident CD cases were more likely than UC or IBDU to require escalation of medical therapy, hospitalisation and bowel resection, especially among those with penetrating or stricturing disease. They had a longer duration of symptoms prior to diagnosis.

CONCLUSION

IBD prevalence and incidence rates are high in Tasmania, comparable to data from other Australasian studies and those from Northern Europe and America. Poorer 12-month clinical outcomes occurred in complicated CD, with greater use of healthcare resources.

Relationship(s) between obesity and inflammatory bowel diseases: possible intertwined pathogenic mechanisms

The inflammatory bowel diseases, Crohn's and ulcerative colitis have increased in incidence and prevalence from the mid-eighteen to the late nineteen centuries. From then to the current twenty-first century there has been a more rapid expansion of these disease to areas previously experiencing low rates. This latter expansion coincides with the current obesity pandemic which also began toward the end of the last century. Although the two diseases have radically different frequencies, there are interesting links between them. Four areas link the diseases. On an epidemiological level, IBD tends to follow a north-south gradient raising the importance of vitamin D in protection. Obesity has very weak relationship with latitude, but both diseases follow adult lactase distributions colliding in this plane. Is it possible that obesity (a low vitamin D condition with questionable response to supplements) reduces effects in IBD? On a pathogenic level, pro-inflammatory processes mark both IBD and obesity. The similarity raises the question of whether obesity could facilitate the development of IBD. Features of the metabolic syndrome occur in both, with or without obesity in IBD. The fourth interaction between the two diseases is the apparent effect of obesity on the course of IBD. There are suggestions that obesity may reduce the efficacy of biologic agents. Yet there is some suggestion also that obesity may reduce the need for hospitalization and surgery. The apparent co-expansion of both obesity and IBD suggests similar environmental changes may be involved in the promotion of both.

Academic Stress May Contribute to the Onset of Pediatric Inflammatory Bowel Diseases

It is currently unclear whether seasonality affects the onset of inflammatory bowel diseases (IBDs: Crohn disease and ulcerative colitis) in children. Here, we examined the records of pediatric patients with IBD diagnosed between 2009 and 2015 in a discovery cohort of 169 cases and a validation cohort of 122 subjects, where the month of symptoms onset could be determined. No seasonal patterns could be identified in respect to conception, birth, and disease onset. An annual rhythm of symptomatic onset, however, correlating with academic semesters was identified. IBD symptoms in the discovery cohort presented significantly more (P = 0.0218) during 5 months including the initiation (August, September, January) and the termination of academic semesters (December, May) compared to any other 5 months of the year. This observation was validated in the independent cohort (P < 0.0001). Our findings imply that academic stress may contribute to disease onset in pediatric IBD, which may improve timely diagnosis.

Epidemiology and hospital resources use in the treatment of ulcerative colitis at gastroenterology units in Spain (EPICURE study)

Background and aim

Nationwide epidemiological data on ulcerative colitis (UC) in Spain are lacking. The primary objective was to assess the epidemiology of UC at hospital gastroenterology units and the use of hospital resources (characteristics and facilities) for the management of UC in Spain.

Methods

A retrospective, multicenter, epidemiological, cross-sectional study (EPICURE study) analyzed data from hospital registries and records from UC patients admitted and treated in 2011 at a representative selection of Spanish sites. The prevalence of UC in gastroenterology units was calculated as the total UC patients divided by the total inhabitants covered by those sites. Incidence was defined as the number of new UC cases during 2011 divided by the total inhabitants covered by those sites.

Results

In 2011, a total of 42,000 patients were attended for UC in gastroenterology units in Spain with a prevalence rate of 88.7 UC cases (95% CI: 69.6-106.0) per 100,000 inhabitants. The incidence rate was of 5.7 cases (95% CI: 1.2-10.8)/100,000 inhabitants. Six percent of patients being attended for UC were hospitalized in the 58 units analyzed in 2011. There were 1075 hospitalizations related to UC in total (approximately 14 per gastroenterology unit; median hospital stay length: 8 days). Six out of 1000 UC patients underwent colectomy in 2011. Near one third (32.7%) were emergency colectomies. Most hospitals had specific IBD units (87.9%) and colorectal surgeons (93.1%).

Conclusions

Our study provides the first national data on the prevalence and incidence of UC in gastroenterology units in Spain. Hospitalization and surgical burden associated with UC was low.

Inflammatory Bowel Diseases: Review of Known Environmental Protective and Risk Factors Involved

Inflammatory bowel diseases consisting of Crohn's disease and ulcerative colitis are chronic inflammatory diseases of the gastrointestinal tract. In addition to genetic susceptibility and disturbances of the microbiome, environmental exposures forming the exposome play an important role. Starting at birth, the cumulative effect of different environmental exposures combined with a predetermined genetic susceptibility is thought to cause inflammatory bowel disease. All these environmental factors are part of a Western lifestyle, suiting the high incidence rates in Europe and the United States. Whereas receiving breastfeeding, evidence of a Helicobacter pylori infection and vitamin D are important protective factors in Crohn's disease as well as ulcerative colitis, increased hygiene, experiencing a bacterial gastroenteritis in the past, urban living surroundings, air pollution, the use of antibiotics, nonsteroidal anti-inflammatory drugs, and oral contraceptives are likely to be the most important risk factors for both diseases. Current cigarette smoking yields a divergent effect by protecting against ulcerative colitis but increasing risk of Crohn's disease, whereas former smoking increases chances of both diseases. This review gives a clear overview of the current state of knowledge concerning the exposome. Future studies should focus on measuring this exposome yielding the possibility of combining all involved factors to one exposome risk score and our knowledge on genetic susceptibility.

Establishment of a rat model of ulcerative colitis with abnormal sapra syndrome of traditional Uyghur medicine and detection of changes in inflammation related factors in colon tissue of this model

AIM

To develop a rat model of ulcerative colitis (UC) with abnormal sapra syndrome and detect the changes in inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) hnRNA and mRNA expression in colon tissues of this model.

METHODS

Based on a rat model of abnormal sapra syndrome, trinitrobenzene sulfonic acid/ethanol was used to induce UC in rats with abnormal sapra syndrome. Rats were randomly divided into two groups: normal group and UC with abnormal sapra syndrome model group. Quantitative RT-PCR was used to detect the differences in iNOS and eNOS hnRNA and mRNA expression in colon tissues of rats in the two groups.

RESULTS

UC with abnormal sapra syndrome was successfully induced as evidenced by the presence of anticipated signs, symptoms and colonic mucosa damage. Compared with the normal group, the expression of iNOS hnRNA in colon tissue was significantly upregulated in the model group (P < 0.05), but the expression of eNOS hnRNA in colon tissue showed no statistical difference between the two groups (P > 0.05). The expression of iNOS and eNOS mRNA was significantly upregulated in the model group compared with the normal group (P < 0.05).

CONCLUSION

The inflammatory factors iNOS and eNOS are involved in the development of UC in rats with abnormal sapra syndrome, and changes in inflammation related factors are mediated by a post-transcriptional regulatory mechanism.

Influence of environmental factors on the onset and course of inflammatory bowel disease

Numerous environmental factors have been linked with inflammatory bowel disease. These include smoking, diet, hygiene, drugs, geographical and psychosocial factors. These factors may either increase the risk of or protect against developing this condition and can also affect the course of illness in a positive or negative manner. A number of studies have examined the influence of environmental factors on inflammatory bowel diseases as a whole as well as on ulcerative colitis and Crohn’s disease separately. As there are differences in the pathogenesis of ulcerative colitis and Crohn’s disease, the effect of environmental factors on their onset and course is not always similar. Some factors have shown a consistent association, while reports on others have been conflicting. In this article we discuss the current evidence on the roles of these factors on inflammatory bowel disease, both as causative/protective agents and as modifiers of disease course.

Latitude, sunshine, and human lactase phenotype distributions may contribute to geographic patterns of modern disease: the inflammatory bowel disease model

Countries with high lactase nonpersistence (LNP) or low lactase persistence (LP) populations have lower rates of some "western" diseases, mimicking the effects of sunshine and latitude. Inflammatory bowel disease (IBD), ie, Crohn's disease and ulcerative colitis, is putatively also influenced by sunshine. Recent availability of worldwide IBD rates and lactase distributions allows more extensive comparisons. The aim of this study was to evaluate the extent to which modern day lactase distributions interact with latitude, sunshine exposure, and IBD rates. National IBD rates, national distributions of LP/LNP, and population-weighted average national annual ultraviolet B exposure were obtained, estimated, or calculated from the literature. Negative binomial analysis was used to assess the relationship between the three parameters and IBD rates. Analyses for 55 countries were grouped in three geographic domains, ie, global, Europe, and non-Europe. In Europe, both latitude and ultraviolet B exposure correlate well with LP/LNP and IBD. In non-Europe, latitude and ultraviolet B exposure correlate weakly with LP/LNP, but the latter retains a more robust correlation with IBD. In univariate analysis, latitude, ultraviolet B exposure, and LP/LNP all had significant relationships with IBD. Multivariate analysis showed that lactase distributions provided the best model of fit for IBD. The model of IBD reveals the evolutionary effects of the human lactase divide, and suggests that latitude, ultraviolet B exposure, and LP/LNP mimic each other because LP/LNP follows latitudinal directions toward the equator. However, on a large scale, lactase patterns also follow lateral polarity. The effects of LP/LNP in disease are likely to involve complex interactions.