Morbidity and mortality before and after bariatric surgery for morbid obesity compared with the general population

Background

Bariatric surgery reduces morbidity and mortality in obese subjects, but it is unclear how rates compare with those in the population. The aim was to assess the risk of admission to hospital for obesity-related co-morbidities and overall mortality after bariatric surgery in relation to the general population.

Methods

A nationwide, population-based cohort study was conducted of all patients who underwent bariatric surgery in Sweden between 1980 and 2006. Each patient was compared with ten age- and sex-matched controls randomly selected from the Total Population Register. Hospital admission for co-morbidities was identified through the Patient Register. Cox proportional regression was used to calculate hazard ratios (HRs).

Results

A total of 13 273 patients underwent bariatric surgery between 1980 and 2006. After surgery, the overall adjusted HR remained increased for myocardial infarction (HR 1·56, 95 per cent confidence interval 1·35 to 1·81), angina pectoris (HR 2·05, 1·84 to 2·31), stroke (HR 2·13, 1·88 to 2·42), hypertension (HR 2·80, 2·61 to 3·01), diabetes (HR 2·44, 2·23 to 2·67) and death (HR 1·24, 1·15 to 1·34) in these patients compared with the general population. The 4161 patients who underwent gastric bypass surgery no longer had a higher risk of diabetes (HR 1·23, 0·88 to 1·72) or myocardial infarction (HR 0·78, 0·42 to 1·45), whereas morbidity remained increased after restrictive surgery in 7855 patients. The adjusted mortality remained higher after both gastric bypass and restrictive surgery.

Conclusion

Gastric bypass, but not restrictive surgery, in patients with morbid obesity seems to reduce the risk of diabetes and myocardial infarction to population levels, but the risk of death remains increased.

Long-term health-related quality of life following surgery for oesophageal cancer

BACKGROUND

The aim of the study was to assess health-related quality of life (HRQL) in patients with surgically cured oesophageal cancer.

METHODS

A Swedish nationwide cohort of patients undergoing oesophagectomy for cancer between April 2001 and January 2004 was studied prospectively, and compared with a Swedish age- and sex-adjusted reference population. Validated European Organisation for Research and Treatment of Cancer quality of life questionnaires were used to assess HRQL at 6 months and 3 years after surgery. A mean score difference of 10 or more between groups was considered clinically relevant and tested further for statistical significance.

RESULTS

Of 358 patients, 117 (32.7 per cent) survived for at least 3 years. Of these, 87 patients (74.4 per cent) responded to the questionnaires. Six months after surgery, most aspects of HRQL were substantially worse than in the reference population with no improvement at 3 years. Patients alive at 3 years reported significantly poorer role and social function, and significantly more problems with fatigue, diarrhoea, appetite loss, nausea and vomiting, than in the reference population.

CONCLUSION

HRQL in long-term survivors after oesophagectomy does not improve between 6 months and 3 years after surgery, and is worse than that in a comparable reference population.

Population-based study of surgical factors in relation to health-related quality of life after oesophageal cancer resection

BACKGROUND

Oesophagectomy for cancer has a negative impact on health-related quality of life (HRQL), but factors influencing postoperative HRQL have been sparsely studied. This study explored how selected surgical factors affected HRQL 6 months after operation.

METHODS

This population-based study was based on a Swedish network of physicians with almost complete nationwide coverage and data on oesophageal cancer surgery collected prospectively between 2001 and 2005. Patients completed validated HRQL questionnaires 6 months after operation. Mean scores with 95 per cent confidence intervals were calculated and clinically relevant differences between groups were analysed in a linear regression model, adjusted for potential confounders.

RESULTS

Some 355 patients were included in the analysis (participation rate 79.6 per cent). Extensive surgery, as indicated by a transthoracic approach, more extensive lymphadenectomy, wider resection margins and a longer duration of operation, was not associated with worse HRQL measures than less extensive operations. Dysphagia was similar in patients who had handsewn and stapled anastomoses. Technical surgical complications had significant deleterious effects on several aspects of HRQL.

CONCLUSION

This study provides no evidence to suggest that less extensive surgery for oesophageal cancer should be recommended from the perspective of HRQL. It is essential, however, that attention be paid to minimizing technical surgical complications.

Severe symptoms of gastro-oesophageal reflux disease are associated with cardiovascular disease and other gastrointestinal symptoms, but not diabetes: a population-based study

BACKGROUND

Few population-based studies have examined comorbidity in relation to gastro-oesophageal reflux disease (GERD).

AIM

To study the association between cardiovascular disease, diabetes, gastrointestinal symptoms and GERD.

METHODS

Population-based, cross-sectional, case-control study based on a large Norwegian health survey conducted in 1995-97. Among 65,333 participants, 3153 persons reporting severe reflux symptoms were defined as cases, and 40,210 persons without such symptoms were defined as controls. Data on cardiovascular disease, diabetes, gastrointestinal symptoms and potential confounders were collected through questionnaires. Odds ratios (OR) with 95% confidence intervals (CI) were estimated using unconditional logistic regression, in crude and adjusted models.

RESULTS

In the crude models, positive associations were observed between myocardial infarction (OR 1.7, 95% CI 1.4-2.1), angina pectoris (OR 2.5, 95% CI 2.1-2.9) and stroke (OR 1.6, 95% CI 1.2-2.1) and risk of GERD. The associations were attenuated in the adjusted models, but remained significant for angina pectoris (OR 1.9, 95% CI 1.6-2.2). No association was observed between diabetes and GERD. Strong positive associations were seen between all studied gastrointestinal symptoms, i.e. nausea, diarrhoea and constipation, and risk of GERD.

CONCLUSIONS

This population-based study indicates that myocardial infarction, angina pectoris, stroke and symptoms of nausea, diarrhoea and constipation are associated with GERD.

Malnutrition after oesophageal cancer surgery in Sweden

BACKGROUND

Oesophageal cancer resection carries a risk of nutritional disorders. The aim of this study was to estimate weight change after surgery in a population-based setting and to identify nutritional problems that might correlate with weight loss.

METHODS

Data were collected through the Swedish Esophageal and Cardia Cancer Register, a nationwide registry of oesophageal cancer surgery. Patients who underwent oesophageal cancer surgery between 2001 and 2004 were followed up until April 2005, and data on patient and tumour characteristics and surgical treatment were collected. Six months after surgery the patients were asked to complete a questionnaire about weight and a health-related quality of life questionnaire (European Organization for Research and Treatment of Cancer (EORTC QLQ-C30) with an oesophageal-specific module (EORTC QLQ-OES18)).

RESULTS

The response rate to the questionnaire was 76.9 per cent and weight change in 226 patients was analysed. Six months after operation 63.7 per cent had lost more than 10 per cent of their preoperative BMI, and 20.4 per cent had lost more than 20 per cent. Appetite loss, eating difficulties and odynophagia were significantly linked to postoperative weight loss, whereas dysphagia or reflux did not correlate with malnutrition.

CONCLUSION

Malnutrition is a considerable problem after oesophagectomy, and is linked to appetite loss, eating difficulties and odynophagia.

Severe gastro-oesophageal reflux symptoms in relation to anxiety, depression and coping in a population-based study

BACKGROUND

The association between psychiatric disorders and gastro-oesophageal reflux symptoms is uncertain, and few population-based studies are available.

AIM

To examine the association between psychiatric and psychological factors and reflux symptoms.

METHODS

Population-based, cross-sectional, case-control study based on two health surveys conducted in the Norwegian county Nord-Trondelag in 1984-1986 and 1995-1997. Reflux symptoms were assessed in the second survey, including 65,333 participants (70% of the county's adult population). 3153 subjects reporting severe reflux symptoms were defined as cases and 40,210 subjects without symptoms were defined as controls. Data were collected in questionnaires. Odds ratio with 95% confidence intervals were estimated using unconditional logistic regression, in adjusted models.

RESULTS

Subjects reporting anxiety without depression had a 3.2-fold (95% CI: 2.7-3.8) increased risk of reflux, subjects with depression without anxiety had a 1.7-fold (95% CI: 1.4-2.1) increased risk and subjects with both anxiety and depression had a 2.8-fold (95% CI: 2.4-3.2) increased risk, compared to subjects without anxiety/depression. We observed a weak inverse association between one measure of covert coping and risk of reflux and a weak positive association between another coping measure and risk of reflux.

CONCLUSIONS

This population-based study indicates that anxiety and depression are strongly associated with reflux symptoms, while no consistent association regarding coping and reflux was found.

The influence of needle catheter jejunostomy on weight development after oesophageal cancer surgery in a population-based study

AIMS

We aimed to assess whether needle catheter jejunostomy (NCJ) influences the weight development or discharge from hospital after oesophageal cancer surgery in an unselected and prospectively collected series of patients.

METHODS

Data regarding patients who underwent oesophageal cancer surgery between April 2001 and October 2004 and were followed up until April 2005 were collected from the Swedish Esophageal and Cardia Cancer Register. Details of patient characteristics, including preoperative body weight and length, tumour characteristics, surgical procedures, including NCJ insertion, complications and ward time were obtained. Six months postoperatively the patients responded to a questionnaire that gave information about postoperative weight development. Relative risks were estimated as odds ratios (ORs) calculated with 95% confidence intervals (CIs) using multinomial logistic regression, adjusted for patient and tumour characteristics, type of treatment, type of hospital and occurrence of complications.

RESULTS

A total of 233 patients participated, among whom 48% received NCJ. Patients with NCJ had a 42% statistically non-significantly decreased risk of weight loss compared to those without NCJ after adjustment for covariates (OR 0.58; 95% CI 0.25-1.39). Patients with NCJ had a non-statistically significantly longer hospital stay than patients without NCJ, but were seemingly less often discharged to other care homes than their own home compare to the group without NCJ (OR 0.62; 95% CI 0.28-1.38).

CONCLUSION

Use of needle catheter jejunostomy might counteract weight loss and facilitate discharge to home after oesophageal cancer resection.

Extended abdominoperineal resection with gluteus maximus flap reconstruction of the pelvic floor for rectal cancer

BACKGROUND

Intraoperative tumour perforation, positive tumour margins, wound complications and local recurrence are frequent difficulties with conventional abdominoperineal resection (APR) for rectal cancer. An alternative technique is the extended posterior perineal approach with gluteus maximus flap reconstruction of the pelvic floor. The aim of this study was to report the technique and early experience of extended APR in a select cohort of patients.

METHODS

The principles of operation are that the mesorectum is not dissected off the levator muscles, the perineal dissection is done in the prone position and the levator muscles are resected en bloc with the anus and lower rectum. The perineal defect is reconstructed with a gluteus maximus flap. Between 2001 and 2005, 28 patients with low rectal cancer were treated accordingly at the Karolinska Hospital.

RESULTS

Two patients had ypT0 tumours, 20 ypT3 and six ypT4 tumours. Bowel perforation occurred in one, the circumferential resection margin (CRM) was positive in two, and four patients had local perineal wound complications. Two patients developed local recurrence after a median follow-up of 16 months.

CONCLUSION

The extended posterior perineal approach with gluteus maximus flap reconstruction in APR has a low risk of bowel perforation, CRM involvement and local perineal wound complications. The rate of local recurrence may be lower than with conventional APR.

Surgeon volume and postoperative mortality after oesophagectomy for cancer

AIM

Oesophagectomy remains the curative treatment of choice for patients with localised oesophageal or cardia cancer, but severe postoperative complications are common. Our aim was to assess the association between surgeon volume and postoperative mortality after oesophagectomy.

METHODS

Prospective, population-based study of Swedish residents diagnosed with oesophageal or cardia cancer, treated with oesophagectomy during the period April 2001 through December 2005. Details concerning patients, tumours, and surgery were collected from the Swedish Oesophageal and Cardia Cancer register. All 607 patients registered during the study period were included in the study. Risk of mortality 30 and 90 days after oesophagectomy was assessed using multivariable logistic regression, expressed in odds ratios (OR) with 95% confidence intervals (CI), adjusted for relevant covariates.

RESULTS

The 30-day mortality in low-, medium-, and high-volume surgeon groups were 7.1%, 2.1%, and 2.6%, respectively. The corresponding 90-day figures were 11.4%, 4.8%, and 8.9%. Adjusted ORs for 30- and 90-day mortality were decreased non-significantly by 58% and 14%, respectively, among patients in the high-volume group, compared to the low-volume group (OR 0.42, 95% CI 0.10-1.80; OR 0.86, 95% CI 0.31-2.38). The mortality rates differed considerably between individual high-volume surgeons, but without any trend of further decreased risk with increasing volume among these surgeons (p values for trend 0.84 and 0.80 for 30- and 90-day mortality, respectively).

CONCLUSION

Patients with resectable oesophageal cancer should be advised to choose a high-volume surgeon, but they should also be aware that differences among individual surgeons might further affect survival.

Gastric acid suppression and risk of oesophageal and gastric adenocarcinoma: a nested case control study in the UK

BACKGROUND

Gastric acid suppressing drugs (that is, histamine(2) receptor antagonists and proton pump inhibitors) could affect the risk of oesophageal or gastric adenocarcinoma but few studies are available.

AIMS

To study the association between long term treatment with acid suppressing drugs and the risk of oesophageal or gastric adenocarcinoma.

PATIENTS

Persons registered in the general practitioners research database in the UK and aged 40-84 years during the period 1994-2001.

METHODS

Population based nested case control study. Multivariable unconditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CI).

RESULTS

In 4 340 207 person years of follow up, 287 patients with oesophageal adenocarcinoma, 195 with gastric cardia adenocarcinoma, and 327 with gastric non-cardia adenocarcinoma were identified, and 10 000 control persons were randomly sampled. "Oesophageal" indication for long term acid suppression (that is, reflux symptoms, oesophagitis, Barrett's oesophagus, or hiatal hernia) rendered a fivefold increased risk of oesophageal adenocarcinoma (odds ratio (OR) 5.42 (95% confidence interval (CI) 3.13-9.39)) while no association was observed among users with a group of other indications, including peptic ulcer and "gastroduodenal symptoms" (that is, gastritis, dyspepsia, indigestion, and epigastric pain) (OR 1.74 (95% CI 0.90-3.34)). "Peptic ulcer" indication (that is, gastric ulcer, duodenal ulcer, or unspecified peptic ulcer) was associated with a greater than fourfold increased risk of gastric non-cardia adenocarcinoma among long term users (OR 4.66 (95% CI 2.42-8.97)) but no such association was found in those treated for a group of other indications (that is, "oesophageal" or "gastroduodenal symptoms") (OR 1.18 (95% CI 0.60-2.32)).

CONCLUSIONS

Long term pharmacological gastric acid suppression is a marker of increased risk of oesophageal and gastric adenocarcinoma. However, these associations are most likely explained by the underlying treatment indication being a risk factor for the cancer rather than an independent harmful effect of these agents per se.

An antireflux stent versus conventional stents for palliation of distal esophageal or cardia cancer: a randomized clinical study

BACKGROUND

Self-expandable metal stents placed across the esophagogastric junction for palliative treatment of malignant strictures may lead to gastroesophageal reflux and pulmonary aspiration. This study compared the effects of a Dua antireflux stent with those of a conventional stent.

METHODS

Patients with incurable cancer of the distal esophagus or gastric cardia were randomly assigned to receive an antireflux stent (n = 19) or a standard stent (n = 22) at nine Swedish hospitals during the period September 1, 2003 to July 31, 2005. Complications were recorded at clinical follow-up visits. Survival rates were assessed through linkage to the Population Register. Dysphagia, reflux symptoms, esophageal pain, dyspnea, and global quality of life were assessed as changes in mean scores between baseline and 1 month after stent insertion through validated questionnaires.

RESULTS

No technical problems occurred during stent placement in the 41 enrolled patients. Fewer patients with complications were observed in the antireflux stent group (n = 3) than in the standard group (n = 8), but no statistically significant difference was shown (p = 0.14). The survival rates were similar in the two groups (p = 0.99; hazard ratio, 1.0; 95% confidence interval, 0.5-2.0). The groups did not differ significantly in terms of studied esophageal or respiratory symptoms or quality of life. Clinically relevant improvement in dysphagia occurred in both groups. Dyspnea decreased after antireflux stent insertion (mean score change, -11), and increased after insertion of standard stent (mean score change, +21).

CONCLUSIONS

Antireflux stents may be used without increased risk of complications, mortality, esophageal symptoms, or reduced global quality of life. These results should encourage large-scale randomized trials that can establish potentially beneficial effects of antireflux stents.

Tamoxifen exposure and risk of oesophageal and gastric adenocarcinoma: a population-based cohort study of breast cancer patients in Sweden

In a population-based cohort study of all women aged over 50 years with breast cancer in the Swedish Cancer Register in 1961–2003, those diagnosed before 31 December 1987 were regarded as unexposed to tamoxifen, whereas those diagnosed after that date were considered potentially exposed. Crosslinkages within the Cancer Register and the Registers of Death and Emigration enabled follow-up. Standardised incidence ratios (SIRs) of oesophageal and gastric cancer represented relative risks. Among 138 885 cohort members contributing with 1 075 724 person-years of follow-up, we found a nonsignificantly increased risk of oesophageal adenocarcinoma during the potential tamoxifen exposure period (SIR 1.60, 95% confidence interval (CI) 0.83–3.08), but the risk estimates decreased with increasing latency interval. No association was observed during the unexposed period. No increased risk of cardia adenocarcinoma was identified in either period. The risk of non-cardia gastric adenocarcinoma was increased in the potential tamoxifen period (SIR 1.27, 1.03–1.57), and almost doubled (SIR 1.86, 95% CI 1.10–3.14) in the period of longest latency (10–14 years). The corresponding overall SIR was increased in the unexposed group also, but here SIR did not increase with longer latency intervals. An increased risk of tobacco-related tumours, that is, oesophageal squamous-cell carcinoma and lung cancer, was limited to the unexposed cohort, indicating that confounding by smoking might explain the increased SIR during the unexposed period. We concluded that there might be a link between tamoxifen and risk of non-cardia gastric adenocarcinoma.

Hormone replacement therapy and risks of oesophageal and gastric adenocarcinomas

Oesophageal and gastric adenocarcinoma share an unexplained male predominance, which would be explained by the hypothesis that oestrogens are protective in this respect. We carried out a nested case–control study of hormone replacement therapy (HRT) among 299 women with oesophageal cancer, 313 with gastric cancer, and 3191 randomly selected control women, frequency matched by age and calendar year in the General Practitioners Research Database in the United Kingdom. Data were adjusted for age, calendar year, tobacco smoking, alcohol consumption, body mass index, hysterectomy, and upper gastrointestinal disorders. Among 1 619 563 person-years of follow-up, more than 50% reduced risk of gastric adenocarcinoma was found among users of HRT compared to nonusers (odds ratio (OR), 0.48, 95% confidence interval (CI) 0.29–0.79). This inverse association appeared to be stronger for gastric noncardia (OR 0.34, 95% CI 0.14–0.78) and weaker for gastric cardia tumours (OR 0.68, 95% CI 0.23–2.01). There was no association between HRT and oesophageal adenocarcinoma (OR 1.17, 95% CI 0.41–3.32).

Airborne occupational exposures and risk of oesophageal and cardia adenocarcinoma

BACKGROUND

The reasons for the increasing incidence of and strong male predominance in patients with oesophageal and cardia adenocarcinoma remain unclear. The authors hypothesised that airborne occupational exposures in male dominated industries might contribute.

METHODS

In a nationwide Swedish population based case control study, 189 and 262 cases of oesophageal and cardia adenocarcinoma respectively, 167 cases of oesophageal squamous cell carcinoma, and 820 frequency matched controls underwent personal interviews. Based on each study participant's lifetime occupational history the authors assessed cumulative airborne occupational exposure for 10 agents, analysed individually and combined, by a deterministic additive model including probability, frequency, and intensity. Furthermore, occupations and industries of longest duration were analysed. Relative risks were estimated by odds ratios (OR), with 95% confidence intervals (CI), using conditional logistic regression, adjusted for potential confounders.

RESULTS

Tendencies of positive associations were found between high exposure to pesticides and risk of oesophageal (OR 2.3 (95% CI 0.9 to 5.7)) and cardia adenocarcinoma (OR 2.1 (95% CI 1.0 to 4.6)). Among workers highly exposed to particular agents, a tendency of an increased risk of oesophageal squamous cell carcinoma was found. There was a twofold increased risk of oesophageal squamous cell carcinoma among concrete and construction workers (OR 2.2 (95% CI 1.1 to 4.2)) and a nearly fourfold increased risk of cardia adenocarcinoma among workers within the motor vehicle industry (OR 3.9 (95% CI 1.5 to 10.4)). An increased risk of oesophageal squamous cell carcinoma (OR 3.9 (95% CI 1.2 to 12.5)), and a tendency of an increased risk of cardia adenocarcinoma (OR 2.8 (95% CI 0.9 to 8.5)), were identified among hotel and restaurant workers.

CONCLUSIONS

Specific airborne occupational exposures do not seem to be of major importance in the aetiology of oesophageal or cardia adenocarcinoma and are unlikely to contribute to the increasing incidence or the male predominance.

Sex hormones and oesophageal adenocarcinoma: influence of childbearing?

The male predominance of oesophageal adenocarcinoma might be explained by oestrogen protection in women. If true, female patients might have sex hormonal disturbances rendering impaired fertility. The influence of childbearing on the risk of oesophageal adenocarcinoma was investigated in a Swedish population-based case (n=63) -control (n=141) study. Childless women were not at increased risk compared to childbearing (OR=0.82; 95% CI=0.25-2.72), as neither were women with 0-1 children compared to women with at least three children (OR=0.93; 95% CI=0.35-2.49). In conclusion, we found no inverse association between childbearing and oesophageal adenocarcinoma.

A nationwide study of the use of self-expanding stents in patients with esophageal cancer in Sweden

BACKGROUND AND STUDY AIMS

Endoscopic insertion of self-expanding metal stents is used for palliative treatment of esophageal and cardia cancer, but the safety profiles, and the influence of age, sex, and hospital volume have not previously been evaluated in a population-based setting.

PATIENTS AND METHODS

A retrospective population-based study was conducted, including all patients treated with esophageal stenting for malignant disease recorded in Swedish national registries in the period 1997 - 2000. Patients with esophageal or cardia cancer were identified in the cancer registry, and those treated with esophageal stenting were selected from the in-patient registry. Survival and emigration were assessed using the registries for causes of death and emigration, respectively. Procedure-related complications were assessed by reviewing medical records.

RESULTS

Among 1052 registered patients with esophageal or cardia cancer, 402 patients (38 %), with a median age of 74 years, were treated with esophageal stenting. After treatment, the median in-hospital stay was 7 days, and the median survival was 100 days. Survival times were similar between age groups and sexes. Stenting was conducted at 38 Swedish hospitals, with a range of 1-59 procedures at each hospital. Among 152 (38 %) patients who were evaluated for complications, 41 (27 %) had complications of some type, while 20 (13 %) experienced direct procedure-related complications. No differences in complication frequencies were found between high-volume and low-volume centers. There were only two procedure-related deaths (1 %), both due to esophageal perforation. No reduction in the median survival time was found in patients with complications.

CONCLUSIONS

Treatment with self-expanding metal stents is a widely used and reasonably safe procedure among patients with malignant dysphagia, independent of sex, age, or hospital volume in Sweden.

Adenocarcinoma of oesophagus: what exactly is the size of the problem and who is at risk?

The incidence of oesophageal adenocarcinoma is increasing and the prognosis is poor. There is a strong predominance of white males, and heredity plays a minor role. The established risk factors are Barrett's oesophagus, gastro-oesophageal reflux, and obesity. Infection with Helicobacter pylori and use of non-steroidal anti-inflammatory drugs might reduce the risk. Medications that relax the lower oesophageal sphincter might contribute to increasing the risk. Among dietary factors, low intake of fruit, vegetables, and cereal fibres seem to increase the risk of oesophageal adenocarcinoma. The role of tobacco smoking is probably limited and alcohol consumption is not a risk factor. It is uncertain which factors cause the increasing incidence. Increasing prevalences of reflux and obesity, and decreasing prevalence of H pylori infection may contribute to this development; however, the sex distributions of these factors do not match the incidence trends well. Endoscopic surveillance for oesophageal adenocarcinoma among persons with reflux and obesity is discussed, but presently there is no evidence that strongly supports such a strategy.

Lifestyle related risk factors in the aetiology of gastro-oesophageal reflux

BACKGROUND/AIM

The aetiology of gastro-oesophageal reflux is largely unknown. The authors' aim was to examine the relation between lifestyle habits and gastro-oesophageal reflux symptoms.

SUBJECTS

Participants of two consecutive public health surveys in Nord-Trondelag, Norway.

METHODS

In a case control study within the two public health surveys, 3153 individuals who in the second survey reported severe heartburn or regurgitation during the last 12 months were defined as cases, while 40 210 people without reflux symptoms constituted the control group. The risk of reflux symptoms was estimated and multivariately calculated as odds ratios in relation to exposure to tobacco smoking, alcohol, coffee, tea, table salt, cereal fibres, and physical exercise.

RESULTS

There was a significant dose response association between tobacco smoking and reflux symptoms. Among people who had smoked daily for more than 20 years the odds ratio was 1.7 (95% confidence interval 1.5 to 1.9) compared with non-smokers. A similar positive association was found for table salt intake. The odds ratio for reflux was 1.7 (95% CI 1.4 to 2.0) among those who always used extra table salt compared with those who never did so. We found moderately strong negative associations between the risk of reflux and exposure to coffee, bread high in dietary fibre content, and frequent physical exercise. Intake of alcohol or tea did not affect the risk of reflux.

CONCLUSIONS

Tobacco smoking and table salt intake seem to be risk factors for gastro-oesophageal reflux symptoms. Dietary fibres and physical exercise may protect against reflux. Alcohol, coffee, and tea do not seem to be risk factors for reflux.

Prevalence of gastro-oesophageal reflux symptoms and the influence of age and sex

BACKGROUND

Most previous studies of reflux symptom prevalence are of small sample size. No reliable data concerning age- and sex-stratified prevalence are available.

METHODS

Among 65,363 adult participants in a public health survey in Nord-Trondelag, Norway, 58,596 (90%) responded concerning occurrence and severity of heartburn or regurgitation during the past 12 months. The prevalence of minor, severe and any reflux symptoms was calculated, including stratification for age and sex. In order to examine whether the relative risk of reflux symptoms between sexes, in different age groups, was affected by other potential risk factors for reflux, confounding effects were tested using multivariate logistic regression. Odds ratios and their 95% confidence intervals were used to estimate relative risks.

RESULTS

Total prevalence of reflux symptoms was 31.4%, whereof 26.0% were minor symptoms and 5.4% severe symptoms. The prevalence of symptoms occurring at least weekly was 11.6%. Among women, the prevalence increased gradually from 22.1% in the youngest age category to 37.5% in the oldest, while among men it gradually increased from 25.8% in the youngest age group to peak at 36.0% between the ages of 50 and 60 years, after which it declined to 33.8% after age 70. A higher prevalence among women compared to men in the oldest age groups was not explained by confounding by body mass, tobacco smoking, alcohol consumption, dietary factors, or physical exercise.

CONCLUSIONS

About every third adult person suffered from reflux symptoms. The prevalence increases linearly with age among women, while among men it peaked between the age of 50 and 70 years and thereafter declined.

Identification of functional clusters of transcription factor binding motifs in genome sequences: the MSCAN algorithm

MOTIVATION

The identification of regulatory control regions within genomes is a major challenge. Studies have demonstrated that regulating regions can be described as locally dense clusters or modules of cis-acting transcription factor binding sites (TFBS). For well-described biological contexts, it is possible to train predictive algorithms to discern novel modules in genome sequences. However, utility of module detection methods has been severely limited by insufficient training data. For only a few tissues can one obtain sufficient numbers of literature-derived regulatory modules.

RESULTS

We present a novel method, MSCAN, that circumvents the training data problem by measuring the statistical significance of any non-overlapping combination of TFBS in a window. Given a set of transcription factor binding profiles, a significance threshold, and a genomic sequence, MSCAN returns putative regulatory regions. We assess performance on two curated collections of regulatory regions; one each for tissue-specific expression in liver and skeletal muscle cells. The efficiency of MSCAN allows for predictive screens of entire genomes.

Serrated adenomas of the cardia

Adenomas of the stomach are histologically classified into tubular and villous adenomas, mixed (tubulovillous) and papillary phenotypes being also recognized. They are localized in the antrum and the body. In a previous work we reported a case of serrated adenoma of the cardia having, at the time of diagnosis, an invasive growth. In this communication we report five newly identified cases of serrated adenomas of the cardia. The five neoplasias were characterized by serrated indentations furnished with dysplastic epithelium. Five out of six serrated adenomas--including the previously reported case--had, in addition, an invasive or a suspected invasive carcinoma. The latter case had at the time of diagnosis lung and liver metastasis. Metastases were also demonstrated in two additional cases. In similarity with other adenoma phenotypes, serrated adenomas of the cardia have a propensity to evolve into invasive carcinoma, a phenomenon that appears to be size-dependent.

Towards identifying lateral gene transfer events

This paper is concerned with evaluating the performance of the model and algorithm in 5 for detecting lateral gene transfers events. Using a Poisson process to describe arrival times of transfer events, a simulation is used to generate "synthetic" gene and species trees. An implementation of an efficient algorithm in 5 is used to estimate the minimum number of transfers necessary to explain disagreements between the generated gene and species trees. Our first result suggests that the algorithm can solve realistic size instances of the problem. Our second result suggests that the mean error and variance are low when saturation does not occur. Additionally, certain plausible evolutionary events allowed by our model of evolution used to generate gene and species trees but not detectable by the algorithm occur rarely implying the framework should work well in practice. Our third, surprising result suggests that the number of optimal scenarios is on average low for realistic input sizes.