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Background: Results from randomized trials of antioxidant supplementation have cast doubt on observational data linking diets high in antioxidants to a reduced risk of cardiovascular diseases. We hypothesized that supplementation of one or a few antioxidants might not simulate the complex actions of all antioxidants in the human diet. We therefore investigated the association between dietary Non Enzymatic Antioxidant Capacity (NEAC), reflecting the antioxidant potential of the whole diet, and the risk of myocardial infarction (MI). Methods: In the Swedish National March Cohort, 34 543 men and women free from cardiovascular diseases and cancer were followed through record linkages from 1997 until 2010. NEAC was assessed with a validated food-frequency questionnaire at baseline. The distribution of NEAC was categorized into sex-specific quartiles. We fitted multivariable Cox proportional hazards regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). Results: During a mean follow-up time of 12.7 years, we identified 1142 incident cases of MI. Successively higher quartiles (Qs) of dietary NEAC were accompanied by a monotonic trend of decreasing MI incidence, both for overall MI (HR Q4 vs Q1: 0.77; 95% CI: 0.61–0.96; p for trend 1⁄4 0.008) and non-fatal MI (HR Q4 vs Q1: 0.72; 95% CI: 0.56–0.92; p for trend 1⁄4 0.004). No such association was found for fatal MI. Conclusions: A diet rich in antioxidants might protect from MI.

BACKGROUND/OBJECTIVES: Antioxidants and polyunsaturated fatty acids (PUFAs) have a role in the human immune defense and may affect the susceptibility to upper respiratory tract infection (URTI). To examine dietary intake of vitamin C, vitamin E, selenium, zinc and PUFAs in relation to URTI incidence in a prospective cohort study. SUBJECTS/METHODS: A total of 1533 Swedish women and men aged 25-64 years were followed for nine months during 2011-2012. Information on dietary intake was assessed through a web-based food frequency questionnaire, and events of URTI were self-reported prospectively as they occurred. Cox proportional hazards regression was applied to obtain incidence rate ratios with 95% confidence intervals. RESULTS: The mean number of URTI events was 0.9 among all participants, 1.0 among women and 0.7 among men. In women, the incidence rate ratios ( 95% confidence interval) for high compared with low intake were 0.69 (0.55-0.88) for vitamin C, 0.77 (0.62-0.96) for vitamin E, 0.57 (0.39-0.83) for docosahexaenoic acid (DHA) and 0.80 (0.65-0.99) for arachidonic acid ( AA). No association was found for selenium or zinc among women. In men, an increased URTI incidence was seen with medium vitamin E intake (1.42 (1.09-1.85)) and high zinc intake (1.50 (1.04-2.16)). No association was found for vitamin C, selenium or PUFAs among men. CONCLUSIONS: We found an inverse association of URTI incidence among women for vitamin C, vitamin E, DHA and AA intake and a positive association among men for vitamin E and zinc intake. The observed gender differences warrant further investigation., QC 20170509

Objective Both observational studies and randomized trials have shown that a diet rich in antioxidants can reduce systemic inflammation and oxidative stress, two conditions that, together with obesity and smoking, are established risk factors for stroke. However, the association between antioxidant intake and risk for stroke is poorly understood, particularly when studying possible interaction with sex. We investigated the relationship of nonenzymatic antioxidant capacity (NEAC) on risk for stroke in a large Swedish prospective cohort. Methods The cohort study included 34 555 men and women from the Swedish National March Cohort. NEAC was assessed using a detailed food frequency questionnaire, collected at baseline. We achieved complete follow-up from enrollment in 1997 through 2010 by record linkage to nationwide registers. We identified 1186 incident cases of a first stroke, of which 860 were ischemic, 201 hemorrhagic, and 125 unspecified. We used multivariable Cox proportional hazards models to estimate adjusted hazard ratios (HR) with 95% confidence intervals (CIs). Results Compared with women in the lowest quartile of NEAC, women in the highest quartile had a 27% lower incidence of total stroke (HR, 0.73; 95% CI, 0.53–0.99; Ptrend = 0.03) and 35% lower incidence of ischemic stroke (HR, 0.65; 95% CI, 0.43–0.99; Ptrend = 0.01). Among men, the relationship between NEAC and risk for stroke was not statistically significant and all HRs were close to unity. Conclusion Findings from the present study suggest that dietary antioxidant capacity from different foods and beverages is inversely associated with risk for stroke, more specifically ischemic stroke, in women.

Study Objective: There are some data to suggest that insufficient sleep, including short sleep duration and sleep disruption, may be associated with an increased risk of cancer. We investigated the association between sleep duration and sleep disruption and risk of prostate cancer. Design: Prospective cohort study. Setting: Sweden. Participants: A total of 14,041 men in the Swedish National March Cohort. Interventions: None. Measurements and Results: Habitual sleep duration and sleep disruption were self-reported in 1997. Prostate cancer diagnoses, including lethal (metastases at diagnosis or death from prostate cancer) and advanced (stage T4, N1, or M1 at diagnosis or death from prostate cancer), were determined from linkage to nationwide cancer registries through 2010. We conducted Cox proportional hazards regression adjusted for potential confounding variables. During 13 years of follow-up, we identified 785 cases of incident prostate cancer, including 118 lethal and 127 advanced cases. Four percent of men reported sleeping 5 h or less a night, and 2% reported sleeping 9 h or more per night. We found no association between sleep duration and risk of prostate cancer overall or for advanced/lethal disease. We also did not find an association between prostate cancer and sleep disruption, as defined by difficulty falling asleep, difficulty maintaining sleep, sleep quality, and restorative power of sleep. Conclusions: In this large prospective study from Sweden, we found no association between habitual sleep duration or sleep disruption and risk of prostate cancer.

Background: To study the impact of the dietary antioxidant quercetin on risk of gastric adenocarcinoma. Patients and methods: Using data from a large Swedish population-based case-control study of gastric cancer (505 cases and 1116 controls), we studied the association between quercetin and risk of anatomic (cardia/noncardia) and histological (intestinal and diffuse) subtypes of gastric cancer. Results: We found strong inverse associations between quercetin and the risk of noncardia gastric adenocarcinoma, with an adjusted odds ratio (OR) of 0.57 (95% confidence interval 0.40-0.83) for the highest quintile (>= 11.9 mg) of daily quercetin intake relative to the lowest quintile of intake (< 4 mg quercetin/day), supported by a significant decreasing linear trend (P value < 0.001). Similar findings were observed for the intestinal and diffuse subtype. For cardia cancer, we found a less evident and nonsignificant inverse relationship. The protection of quercetin appeared to be stronger among female smokers, with the OR leveled of at values < 0.2 in quintiles 3-5 (> 6 mg quercetin/day). Conclusions: High dietary quercetin intake is inversely related to the risk of noncardia gastric adenocarcinoma, and the protection appears to be particularly strong for women exposed to oxidative stress, such as tobacco smoking.

Dialysis has been used in the treatment of patients with end-stage renal disease since the 1960s. Recently, several large observational studies have been conducted to assess whether early initiation of dialysis prolongs survival, as compared with late initiation. However, these studies have used analytic approaches which are likely to suffer from either lead-time bias or immortal-time bias. In this paper, the authors demonstrate that recently developed methods in the causal inference literature can be used to avoid both types of bias and accurately estimate the ideal time for dialysis initiation from observational data. This is illustrated using data from a nationwide population-based cohort of patients with chronic kidney disease in Sweden (1996-2003). © 2011 The Author.

Contains fulltext : 52946.pdf (publisher's version ) (Closed access), Helicobacter pylori (H. pylori), atrophic gastritis, dietary and life-style factors have been associated with gastric cancer (GC). These factors have been evaluated in a large case-control study nested in the European Prospective Investigation into Cancer and Nutrition carried out in 9 countries, including the Mediterranean area. Participants, enrolled in 1992-1998, provided life-style and dietary information and a blood sample (360,000; mean follow-up: 6.1 years). For 233 GC cases diagnosed after enrolment and their 910 controls individually-matched by center, gender, age and blood donation date H. pylori antibodies (antilysate and antiCagA) and plasma Pepsinogen A (PGA) were measured by ELISA methods. Severe chronic atrophic gastritis (SCAG) was defined as PGA circulating levels <22 microg/l. Overall, in a conditional logistic regression analysis adjusted for education, smoke, weight and consumption of total vegetables, fruit, red and preserved meat, H. pylori seropositivity was associated with GC risk. Subjects showing only antibodies anti-H. pylori lysate, however, were not at increased risk, while those with antiCagA antibodies had a 3.4-fold increased risk. Overall, the odds ratio associated with SCAG was 3.3 (95% CI 2.2-5.2). According to site, the risk of noncardia GC associated with CagA seropositivity showed a further increase (OR 6.5; 95% CI 3.3-12.6); on the other hand, a ten-fold increased risk of cardia GC was associated with SCAG (OR 11.0; 95% CI 3.0-40.9). These results support the causal relationship between H. pylori CagA+ strains infection, and GC in these European populations even after taking into account dietary habits. This association was limited to distal GC, while serologically defined SCAG was strongly associated with cardia GC, thus suggesting a divergent risk pattern for these 2 sites.

BACKGROUND AND STUDY AIM: Few previous studies have addressed the agreement between endoscopy and histology regarding Barrett's oesophagus in unselected endoscopy patients. Our aim was to quantify this agreement, and to study its relation to clinical and endoscopic characteristics in consecutive patients coming for first-time gastroscopy. METHODS: We invited consecutive patients aged 18-79 years and endoscoped for the first time at endoscopy units exclusively serving defined catchment areas in southeast Sweden. Endoscopic and clinical data were recorded according to a predetermined protocol, and biopsies were taken from the distal oesophagus in all patients. RESULTS: Among 705 patients included, 17% [95% confidence interval (CI): 14-20] had endoscopically visible columnar mucosa above the oesophagogastric junction and 38% (95% CI: 34-42) had columnar mucosa in at least one biopsy irrespective of the endoscopic finding. The overall concordance between endoscopy and histology regarding presence (or absence) of columnar mucosa above the oesophagogastric junction was 74% (95% CI: 71-77) and the agreement beyond chance, as measured by Kappa (?) statistics, was fair, ?=0.38 (95% CI: 0.32-0.45). The agreement between the endoscopic assessment and intestinal metaplasia at biopsy was 86% (95% CI: 83-88), but ? was only 0.31 (95% CI: 0.21-0.41). Our data were consistent with a lower threshold for macroscopic detection of columnar epithelium above the oesophagogastric junction, when risk factors for Barrett's oesophagus were present. CONCLUSION: The agreement between macroscopic and microscopic assessments of Barrett's oesophagus is no more than fair, and partly dependent on the presence of patient characteristics suggestive of pathology in this region. © 2007 Lippincott Williams & Wilkins, Inc.

Objective. Given its often subclinical course, Barrett's oesophagus (BO) hardly lends itself to epidemiologically stringent evaluations. The objective of this study was to investigate risk factors for incident BO diagnosed in a defined population in southeast Sweden while paying particular attention to epidemiological aspects of the study design. Material and methods. Consecutive patients (aged 18-79 years) who were endoscoped with new indications at units exclusively responsible for all gastroscopies in defined catchment area populations were invited to take part in the study. Biopsies were taken above and immediately below the gastro-oesophageal junction, and exposure information was collected through self-administered questionnaires. Endoscopy-room-based cross-sectional data from 604 patients were supplemented with exposure data from 160 population controls. Associations, expressed as odds ratios (ORs), were modelled by means of multivariable logistic regression. Results. In the comparison with population controls, reflux symptoms and smoking indicated a 10.7- and 3.3-fold risk, respectively, for BO (95% confidence interval (CI) 3.5-33.4 and 1.1-9.9, respectively). Body mass was unrelated to risk. In the cross-sectional analysis among endoscopy-room patients, reflux symptoms were associated with an OR of 2.0 (95% CI 0.8-5.0). This association was, however, modified by the subjunctional presence of Helicobacter pylori, although the infection was not in itself significantly connected with risk, a combination of reflux symptoms and H. pylori infection was linked to an almost 5-fold risk (95% CI 1.4-16.5) as compared with the absence of both factors. The BO prevalence increased by 5% per year of age (95% CI 1-9%). Conclusions. Reflux is the predominant risk factor for BO, and proximal gastric colonization of H. pylori seems to amplify this risk. © 2007 Taylor & Francis.

We evaluated the risk of bladder cancer in a cohort of 79,280 Swedish men hospitalised for benign prostatic hyperplasia (BPH), identified in the Swedish Inpatient Register between 1964 and 1983 and followed until 1989 via multiple record linkages with nationwide data on cancer registry, death and emigration. Standardised incidence ratios (SIRs), the ratios of the observed to the expected numbers of incident bladder cancers, were used to calculate the risk associated with BPH. The expected number was calculated by multiplying the number of person-years by the age-specific cancer incidence rates in Sweden for each 5-year age group and calendar year of observation. Analyses were stratified by BPH treatment, latency, calendar year and presence of genitourinary (GU) comorbid conditions. After excluding the first 3 years of follow-up after the index hospitalisation, we observed 506 incident bladder cancer cases during follow-up in the cohort. No overall increased risk of bladder cancer was apparent in our main analysis involving the entire BPH cohort. However, among BPH patients with transurethral resection of the prostate (TURP), there was an increased risk in all follow-up periods; SIRs of bladder cancer during years 4-6 of follow-up was 1.22 (95% confidence interval=1.02-1.46), 1.32 for 7-9 years of follow-up, and 1.47 for 10-26 years of follow-up. SIRs of bladder cancer among TURP-treated BPH patients were particularly elevated among those with comorbid conditions of the GU tract (e.g., stone, infection, etc.); 1.72, 1.74 and 2.01 for 4-6, 7-9, 10-26 years of follow-up, respectively, and also for those whose diagnoses occurred before 1975, when TURP was more likely to be performed by a urologist than a general practitioner: 1.87, 1.90 and 1.74, respectively. These findings suggest that BPH overall is not associated with bladder cancer risk. However, among men treated with TURP, particularly those with other comorbid GU tract conditions, risk of bladder cancer was elev

Improved methods for quantitative self-reports of total physical activity in epidemiological studies are needed. We evaluated randomly selected individuals' ability to integrate their perception of physical activity over time to produce an estimate of the usual level, using a novel instrument for self-quantification of energy expenditure. A population-based sample of 418 Swedish men and women, age 20-59, completed a questionnaire containing the new instrument. For validation, three 24 hour recalls by phone served as gold standard. Reproducibility was assessed through administering the instrument another three times. The validation involved 133 subjects and another 160 completed the reproducibility evaluation. Pearson correlation between usual daily energy expenditure measured by the instrument and the mean of the 24 hour recalls was 0.73. After subdividing the self-reported daily energy expenditure and the mean of the 24 hour recalls into quintiles, 83.5% of the participants remained in the same quintile, or one quintile apart. There was a tendency towards overestimation of usual daily physical activity. This was significantly associated with low education. Reproducibility showed an intraclass correlation of 0.55. Although integrated reports of usual daily energy expenditure over longer periods seem to be afflicted with a tendency of overestimation, total energy expenditure can be estimated with reasonable validity and reproducibility using our instrument., QC 20100525

Few large-scale epidemiologic studies have quantified the possible link between obesity and chronic renal failure (CRF). This study analyzed anthropometric data from a nationwide, population-based, case-control study of incident, moderately severe CRF. Eligible as cases were all native Swedes who were aged 18 to 74 yr and had CRF and whose serum creatinine for the first time and permanently exceeded 3.4 mg/dl (men) or 2.8 mg/dl (women) during the study period. A total of 926 case patients and 998 control subjects, randomly drawn from the study base, were enrolled. Face-to-face interviews, supplemented with self-administered questionnaires, provided information about anthropometric measures and other lifestyle factors. Logistic regression models with adjustments for several co-factors estimated the relative risk for CRF in relation to body mass index (BMI). Overweight (BMI>or=25 kg/m2) at age 20 was associated with a significant three-fold excess risk for CRF, relative to BMI<25. Obesity (BMI>or=30) among men and morbid obesity (BMI>or=35) among women anytime during lifetime was linked to three- to four-fold increases in risk. The strongest association was with diabetic nephropathy, but two- to three-fold risk elevations were observed for all major subtypes of CRF. Analyses that were confined to strata without hypertension or diabetes revealed a three-fold increased risk among patients who were overweight at age 20, whereas the two-fold observed risk elevation among those who had a highest lifetime BMI of >35 was statistically nonsignificant. Obesity seems to be an important-and potentially preventable-risk factor for CRF. Although hypertension and type 2 diabetes are important mediators, additional pathways also may exist.

For determining whether smoking is associated with an increased risk for chronic renal failure (CRF) overall and by type of renal disease, smoking data were analyzed from a nationwide population-based case-control study. Eligible as cases were native 18- to 74-yr-old Swedes whose serum creatinine for the first time and permanently exceeded 3.4 mg/dl (men) or 2.8 mg/dl (women). A total of 926 cases (78% of all eligible) and 998 control subjects (75% of 1330 randomly selected subjects from the source population), frequency matched to the cases by gender and age within 10 yr, were included. A face-to-face interview and a self-administered questionnaire provided information about smoking habits and other lifestyle factors. Logistic regression models estimated odds ratios (OR) as measures of relative risk for disease-specific types of CRF among smokers compared with never-smokers. Despite a modest and nonsignificant overall association, the risk increased with high daily doses (OR among smokers of >20 cigarettes/d, 1.51; 95% confidence interval [CI], 1.06 to 2.15), long duration (OR among smokers for >40 yr, 1.45; 95% CI, 1.00 to 2.09), and a high cumulative dose (OR among smokers with >30 pack-years, 1.52; 95% CI, 1.08 to 2.14). Smoking increased risk most strongly for CRF classified as nephrosclerosis (OR among smokers with >20 pack-years, 2.2; 95% CI, 1.3 to 3.8), but significant positive associations were also noted with glomerulonephritis. This study thus suggests that heavy cigarette smoking increases the risk of CRF for both men and women, at least CRF classified as nephrosclerosis and glomerulonephritis.

Exposure to organic solvents has been suggested to cause or exacerbate renal disease, but methodologic concerns regarding previous studies preclude firm conclusions. We examined the role of organic solvents in a population-based case-control study of early-stage chronic renal failure (CRF). All native Swedish residents aged 18 to 74 yr, living in Sweden between May 1996 and May 1998, formed the source population. Incident cases of CRF in a pre-uremic stage (n = 926) and control subjects (n = 998), randomly selected from the study base, underwent personal interviews that included a detailed occupational history. Expert rating by a certified occupational hygienist was used to assess organic solvent exposure intensity and duration. Relative risks were estimated by odds ratios (OR) in logistic regression models, with adjustment for potentially important covariates. The overall risk for CRF among subjects ever exposed to organic solvents was virtually identical to that among never-exposed (OR, 1.01; 95% confidence interval [CI], 0.81 to 1.25). No dose-response relationships were observed for lifetime cumulative solvent exposure, average dose, or exposure frequency or duration. The absence of association pertained to all subgroups of CRF: glomerulonephritis (OR, 0.96; 95% CI, 0.68 to 1.34), diabetic nephropathy (OR, 1.02; 95% CI, 0.74 to 1.41), renal vascular disease (OR, 1.16; 95% CI, 0.76 to 1.75), and other renal CRF (OR, 0.92; 95% CI, 0.66 to 1.27). The results from a nationwide, population-based study do not support the hypothesis of an adverse effect of organic solvents on CRF development, in general. Detrimental effects from subclasses of solvents or on specific renal diseases cannot be ruled out.

Background: Low socio-economic status is associated with the occurrence of several different chronic diseases, but evidence regarding renal disease is scant. To explore whether the risk of chronic renal failure varies by socio-economic status, we performed a population-based case-control study in Sweden. Methods: All native residents from May 1996 to May 1998, aged 18-74 years, formed the source population. Cases (n = 926) were incident patients with chronic renal failure in a pre-uraemic stage. Control subjects (n = 998) were randomly selected within the source population. Exposures were assessed at personal interviews and relative risks were estimated by odds ratios (OR) in logistic regression models, with adjustment for age, sex, body mass index (BMI), smoking, alcohol consumption and regular analgesics use. Results: In families with unskilled workers only, the risk of chronic renal failure was increased by 110% [OR = 2.1; 95% confidence interval (CI), 1.1-4.0] and 60% (OR = 1.6; 95% CI, 1.0-2.6) among women and men, respectively, relative to subjects living in families in which at least one member was a professional. Subjects with 9 years or less of schooling had a 30% (OR = 1.3; 95% CI, 1.0-1.7) higher risk compared with those with a university education. The excess risk was of similar magnitude regardless of underlying renal disease. Conclusions: Low socio-economic status is associated with an increased risk of chronic renal failure. The moderate excess was not explained by age, sex, BMI, smoking, alcohol or analgesic intake. Thus, socio-economic status appears to be an independent risk indicator for chronic renal failure in Sweden.