The Association Between Tobacco Use and Risk of COVID-19 Infection and Clinical Outcomes in Sweden: A Population-Based Study.

Background: The association between tobacco use and COVID-19 is controversial. During the early course of the pandemic, limited testing prevented studying a wide spectrum of clinical manifestations. Objective: To examine the potential causal association between tobacco use and COVID-19 during the second wave (1 October 2020-30 June 2021) of the pandemic in Stockholm, Sweden. Methods: A population-based cohort study was conducted in the Stockholm region of Sweden, with information on tobacco use collected prior to the pandemic. Adjusted relative risks (RR) of COVID-19 and 95% confidence intervals (CI) were calculated, contrasting current smokers and snus users to non-users of tobacco. Results: Compared with non-users of tobacco, current smokers had a lower risk of COVID-19 (RR 0.78, 95% CI = 0.75-0.81) and of hospitalisation for the disease. Current snus users had a higher risk of COVID-19. Heavy smokers and snus users had longer hospital stays than non-users of tobacco. Conclusion: Tobacco use may have a different impact on the risk of being infected with SARS-CoV-2 and the risk of developing severe clinical manifestations. Further research is needed to determine the underlying mechanisms.

Current tobacco use and COVID-19 diagnoses in a cohort of adult clients of public dental clinics in Sweden.

Smoking has been linked with both increased and decreased risk of COVID-19, prompting the hypothesis of a protective role of nicotine in the pathogenesis of the disease. Studies of the association between use of smokeless tobacco and COVID-19 would help refining this hypothesis. We analysed data from 424,386 residents in the Stockholm Region, Sweden, with information on smoking and smokeless tobacco (snus) use prior to the pandemic obtained from dental records. Diagnoses of COVID-19 between February and October 2020 were obtained from health-care registers. We estimated the risk of receiving a diagnosis of COVID-19 for current smokers and for current snus users relative to non-users of tobacco, adjusting for potential confounders (aRR). The aRR of COVID -19 was elevated for current snus users (1.09 ;95%CI = 0.99-1.21 among men and 1.15; 95%CI = 1.00-1.33 among women). The risk for women consuming more than 1 can/day was twice as high as among non-users of tobacco. Current smoking was negatively associated with risk of COVID-19 (aRR = 0.68; 95% CI = 0.61-0.75); including hospital admission (aRR = 0.60; 95% CI = 0.47-0.76) and intensive care (aRR = 0.43; 95% CI = 0.21-0.89). The hypothesis of a protective effect of tobacco nicotine on COVID-19 was not supported by the findings. The negative association between smoking and COVID-19 remains unexplained.

Prediction of a time-sensitive condition among patients with dizziness assessed by the emergency medical services.

BACKGROUND: Dizziness is a relatively common symptom among patients who call for the emergency medical services (EMS). AIM: To identify factors of importance for the early identification of a time-sensitive condition behind the symptom of dizziness among patients assessed by the EMS. METHODS: All patients assessed by the EMS and triaged using Rapid Emergency Triage and Treatment (RETTS) for adults code 11 (=dizziness) in the 660,000 inhabitants in the Municipality of Gothenburg, Sweden, in 2016, were considered for inclusion. The patients were divided into two groups according to the final diagnosis (a time-sensitive condition, yes or no). RESULTS: There were 1536 patients who fulfilled the inclusion criteria, of which 96 (6.2%) had a time-sensitive condition. The majority of these had a stroke/transitory ischaemic attack (TIA). Eight predictors of a time-sensitive condition were identified. Three were associated with a reduced risk: 1) the dizziness was of a rotatory type, 2) the dizziness had a sudden onset and 3) increasing body temperature. Five were associated with an increased risk: 1) sudden onset of headache, 2) a history of head trauma, 3) symptoms of nausea or vomiting, 4) on treatment with anticoagulants and 5) increasing systolic blood pressure. CONCLUSION: Among 1536 patients who were triaged by the EMS for dizziness, 6.2% had a time-sensitive condition. On the arrival of the EMS, eight factors were associated with the risk of having a time-sensitive condition. All these factors were linked to the type of symptoms or to clinical findings on the arrival of the EMS or to the recent clinical history.

Risk of transition from occasional neck/back pain to long-duration activity limiting neck/back pain: a cohort study on the influence of poor work ability and sleep disturbances in the working population in Stockholm County.

OBJECTIVES: The prevalence of neck/back pain (NBP) is high worldwide. Limited number of studies have investigated workers with occasional NBP regarding the risk of developing long-duration activity limiting NBP (LNBP). The objectives were to assess (1) the effect of poor work ability and sleep disturbances in persons with occasional NBP on the risk of LNBP, and (2) the interaction effect of these exposures. DESIGN: Cohort study based on three subsamples from the Stockholm Public Health Cohort. SETTINGS: The working population in Stockholm County. PARTICIPANTS: Persons aged 18-60 years, reporting occasional NBP the past 6 months at baseline year 2010 (n=16 460). MEASURES: Work ability was assessed with items from the Work Ability Index, perceived mental and/or physical work ability. Sleep disturbances were self-reported current mild/severe disturbances. The outcome in year 2014 was reporting NBP the previous 6 months, occurring ≥couple of days per week and resulting in decreased work ability/restricted other daily activities. The additive effect of having both poor work ability and sleep disturbances was modelled with a dummy variable, including both exposures. Poisson log-linear regression was used to calculate risk ratios (RRs) and 95% CIs. RESULTS: At follow-up, 9% had developed LNBP. Poor work ability and sleep disturbances were independent risk factors for LNBP; adjusted RR 1.7 (95% CI: 1.4 to 2.0) and 1.4 (95% CI: 1.2 to 1.5), respectively. No additive interaction was observed. CONCLUSION: Workers with occasional NBP who have poor work ability and/or sleep disturbances are at risk of developing LNBP. Having both conditions does not exceed additive risk.

Are respiratory disorders risk factors for troublesome low-back pain? A study of a general population cohort in Sweden.

PURPOSE: A multi-morbidity perspective of troublesome low back pain (LBP) has been highlighted for example in relation to respiratory disorders. Our purpose was to investigate whether respiratory disorders are risk factors for reporting troublesome LBP in people with no or occasional LBP at baseline. METHODS: This prospective cohort study was based on the Stockholm Public Health Cohort 2006/2010. We included adults reporting no or occasional LBP the last 6 months at baseline (n = 17,177). Exposures were self-reported asthma and/or Chronic Obstructive Pulmonary Disease (COPD). Outcome was troublesome LBP defined as reporting LBP a couple of days per week or more often that restricted work capacity or hindered daily activities to some or to a high degree, the last 6 months. Binomial regression models were used to calculate risk ratios (RR) with 95% confidence intervals (95% CI). RESULTS: Adjusted results indicate that those suffering from asthma had a risk of troublesome LBP at follow-up (RR 1.29, 95% CI 0.92-1.81) as do those suffering from COPD (RR 2.0, 95% CI 1.13-3.56). If suffering from asthma and concurrent COPD the RR was 3.55 (95% CI 1.58-7.98). CONCLUSION: Our findings indicate that suffering from asthma and/or COPD increases the risk of developing troublesome LBP, which highlights the importance to consider the overall health of people at risk of troublesome LBP and to take the multi-morbidity perspective into consideration. Future longitudinal studies are needed to confirm our findings. These slides can be retrieved under Electronic Supplementary Material.

Quality Control of Compounded Crystalloid Fluids for Intravenous Delivery to Horses.

BACKGROUND: Periodic lack of availability and high cost of commercially produced isotonic fluids for intravenous (IV) use in horses have increasingly led to use of home-made or commercially compound fluids by veterinarians. Data regarding the quality control and safety of compounded fluids would be of benefit to equine veterinarians. OBJECTIVES: To compare electrolyte concentrations, sterility, and endotoxin contamination of commercially available fluids to 2 forms of compounded isotonic crystalloid fluids intended for IV use in horses. METHODS: Prospective study. Two methods of preparing compounded crystalloids formulated to replicate commercial Plasma-Lyte A (Abbott, Chicago, IL) were compared. One formulation was prepared by a hand-mixed method involving chlorinated drinking water commonly employed by equine practitioners, and the other was prepared by means of ingredients obtained from a commercial compounding pharmacy. The variables for comparison were electrolyte concentrations, sterility, and presence of endotoxin contamination. RESULTS: Electrolyte concentrations were consistent within each product but different between types of fluids (P < 0.0001). Hand-mixed fluids had significantly more bacterial contamination compared to commercial Plasma-Lyte A (P = 0.0014). One of the hand-mixed fluid samples had detectable endotoxin contamination. CONCLUSIONS AND CLINICAL IMPORTANCE: Chlorinated drinking water is not an acceptable source of water to compound isotonic fluids for IV administration. Equine practitioners should be aware of this risk and obtain the informed consent of their clients.

Smokeless tobacco (snus) is associated with an increased risk of type 2 diabetes: results from five pooled cohorts.

BACKGROUND: Smoking and nicotine exposure increase insulin resistance and the risk of type 2 diabetes. Swedish smokeless tobacco (snus) is high in nicotine, and its use is prevalent in Scandinavian countries, but few studies have investigated snus use in relation to diabetes risk. OBJECTIVE: To explore the association between snus use and risk of type 2 diabetes using pooled data from five cohorts. METHODS: Analyses were based on prospective studies conducted between 1990 and 2013 including 54 531 never-smoking men and 2441 incident cases of type 2 diabetes identified through screening, self-reporting and hospital and prescription registries. Hazard ratios (HRs) and 95% confidence intervals (CIs) were assessed and adjusted for age, body mass index, educational level, alcohol consumption and physical activity. RESULTS: Compared to never users, the HR of type 2 diabetes was 1.15 (95% CI: 1.00-1.32) in current users of snus. In individuals consuming 5-6 boxes per week, the HR was 1.42 (95% CI: 1.07-1.87); in those consuming ≥7 boxes per week, the HR was 1.68 (95% CI: 1.17-2.41). Each additional box of snus consumed per week yielded an HR of 1.08 (95% CI: 1.01-1.16). CONCLUSION: Our findings indicate that high consumption of snus is a risk factor for type 2 diabetes. The risk was similar to that in smokers, implying that smokers will not reduce their risk of type 2 diabetes by changing to snus use. The results also support the notion that nicotine increases the risk of type 2 diabetes.

Development of a pathway model to assess the exposure of European pine trees to pine wood nematode via the trade of wood.

Pine wood nematode (PWN), Bursaphelenchus xylophilus, is a threat for pine species (Pinus spp.) throughout the world. The nematode is native to North America, and invaded Japan, China, Korea, and Taiwan, and more recently Portugal and Spain. PWN enters new areas through trade in wood products. Once established, eradication is not practically feasible. Therefore, preventing entry of PWN into new areas is crucial. Entry risk analysis can assist in targeting management to reduce the probability of entry. Assessing the entry of PWN is challenging due to the complexity of the wood trade and the wood processing chain. In this paper, we develop a pathway model that describes the wood trade and wood processing chain to determine the structure of the entry process. We consider entry of PWN through imported coniferous wood from China, a possible origin of Portuguese populations, to Europe. We show that exposure increased over years due to an increase in imports of sawn wood. From 2000 to 2012, Europe received an estimated 84 PWN propagules from China, 88% of which arose from imported sawn wood and 12% from round wood. The region in Portugal where the PWN was first reported is among those with the highest PWN transfer per unit of imported wood due to a high host cover and vector activity. An estimated 62% of PWN is expected to enter in countries where PWN is not expected to cause the wilt of pine trees because of low summer temperatures (e.g., Belgium, Sweden, Norway). In these countries, PWN is not easily detected, and such countries can thus serve as potential reservoirs of PWN. The model identifies ports and regions with high exposure, which helps targeting monitoring and surveillance, even in areas where wilt disease is not expected to occur. In addition, we show that exposure is most efficiently reduced by additional treatments in the country of origin, and/or import wood from PWN-free zones. Pathway modelling assists plant health managers in analyzing risks along the pathway and planning measures for enhancing biosecurity.

Maternal polycystic ovary syndrome and the risk of autism spectrum disorders in the offspring: a population-based nationwide study in Sweden.

Although many studies indicate the interplay of genetic and environmental factors in the etiology of autism spectrum disorder (ASD), our limited understanding of the underlying mechanisms hampers the development of effective ways of detecting and preventing the disorder. Recent studies support the hypothesis that prenatal androgen exposure contributes to the development of ASD. This would suggest that maternal polycystic ovary syndrome (PCOS), a condition associated with excess androgens, would increase the risk of ASD in the offspring. We conducted a matched case-control study nested within the total population of Sweden (children aged 4-17 who were born in Sweden from 1984 to 2007). The sample consisted of 23 748 ASD cases and 208 796 controls, matched by birth month and year, sex and region of birth. PCOS and ASD were defined from ICD codes through linkage to health-care registers. Maternal PCOS increased the odds of ASD in the offspring by 59%, after adjustment for confounders (odds ratio (OR) 1.59, 95% confidence interval (CI) 1.34-1.88). The odds of offspring ASD were further increased among mothers with both PCOS and obesity, a condition common to PCOS that is related to more severe hyperandrogenemia (OR 2.13, 95% CI 1.46-3.10). Risk estimates did not differ between sexes. In conclusion, children of women with PCOS appear to have a higher risk of developing ASD. This finding awaits confirmation, and exploration of potentially underlying mechanisms, including the role of sex steroids in the etiology of ASD.

Assessment of trauma patients.

Trauma is a major contributor to global mortality and morbidity with a notable difference between low income countries (LIC) and high to moderate income countries (HMIC). The modality of trauma differs globally; however, the most notable cause is pedestrian vs. vehicle and road traffic collision respectively. It is imperative that patients who have sustained a traumatic injury are managed in an appropriate and timely manner. Part 1 of the article will address the aetiology and demographic distribution of trauma globally and part 2 of the article will provide information about structured assessment and management of trauma patients.

Do eating disorders in parents predict eating disorders in children? Evidence from a Swedish cohort.

OBJECTIVE: We investigated whether parental eating disorders (ED) predict ED in children, using a large multigeneration register-based sample. METHOD: We used a subset of the Stockholm Youth Cohort born 1984-1995 and resident in Stockholm County in 2001-2007 (N = 286,232), The exposure was a diagnosed eating disorder in a parent; the outcome was any eating disorder diagnosis in their offspring, given by a specialist clinician, or inferred from an appointment at a specialist eating disorder clinic. A final study sample of 158,697 (55.4%) had data on these variables and confounding factors and contributed a total of 886,241 person years to the analysis. RESULTS: We found good evidence in support of the hypothesis that ED in either parent are independently associated with ED in their female children (HR 1.97 (95% CI: 1.17-3.33), P = 0.01) and that ED in mothers are independently associated with ED in their female children (HR 2.35 (95% CI: 1.39-3.97) P = 0.001). Numbers were too low to permit separate analysis of ED in parents and their male children. CONCLUSION: Eating disorders in parents were associated with ED in children. This study adds to our knowledge about the intergenerational transmission of ED, which will help identify high-risk groups and brings about the possibility of targeted prevention.

Testing Ødegaard's selective migration hypothesis: a longitudinal cohort study of risk factors for non-affective psychotic disorders among prospective emigrants.

BACKGROUND: The selection hypothesis posits that the increased rates of psychosis observed among migrants are due to selective migration of people who are predisposed to develop the disorder. To test this hypothesis, we examined whether risk factors for psychosis are more prevalent among future emigrants. METHOD: A cohort of 49,321 Swedish military conscripts was assessed at age 18 years on cannabis use, IQ, psychiatric diagnosis, social adjustment, history of trauma and urbanicity of place of upbringing. Through data linkage we examined whether these exposures predicted emigration out of Sweden. We also calculated the emigrants' hypothetical relative risk compared with non-emigrants for developing a non-affective psychotic disorder. RESULTS: Low IQ [odds ratio (OR) 0.5, 95% confidence interval (95% CI) 0.3-0.9] and 'poor social adjustment' (OR 0.4, 95% CI 0.2-0.8) were significantly less prevalent among prospective emigrants, whereas a history of urban upbringing (OR 2.3, 95% CI 1.4-3.7) was significantly more common. Apart from a non-significant increase in cannabis use among emigrants (OR 1.6, 95% CI 0.8-3.1), there were no major group differences in any other risk factors. Compared to non-emigrants, hypothetical relative risks for developing non-affective psychotic disorder were 0.7 (95% CI 0.4-1.2) and 0.8 (95% CI 0.7-1.0), respectively, for emigrants narrowly and broadly defined. CONCLUSIONS: This study adds to an increasing body of evidence opposing the selection hypothesis.

Snus (Swedish smokeless tobacco) use and risk of stroke: pooled analyses of incidence and survival.

BACKGROUND: Snus is a moist smokeless tobacco product with high nicotine content. Its use has a short-term effect on the cardiovascular system, but the relationship between snus use and stroke is unclear. OBJECTIVE: The aim of this study was to assess the associations between use of snus and incidence of and survival after stroke, both overall and according to subtypes. METHODS: Pooled analyses of eight Swedish prospective cohort studies were conducted, including 130 485 men who never smoked. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) of incidence and death after diagnosis using Cox proportional hazard regression models and case fatality and survival using logistic regression and Kaplan-Meier methods, respectively. RESULTS: No associations were observed between the use of snus and the risk of overall stroke (HR 1.04, 95% CI 0.92-1.17) or of any of the stroke subtypes. The odds ratio (OR) of 28-day case fatality was 1.42 (95% CI 0.99-2.04) amongst users of snus who had experienced a stroke, and the HR of death during the follow-up period was 1.32 (95% CI 1.08-1.61). CONCLUSION: Use of snus was not associated with the risk of stroke. Hence, nicotine is unlikely to contribute importantly to the pathophysiology of stroke. However, case fatality was increased in snus users, compared with nonusers, but further studies are needed to determine any possible causal mechanisms.

Severe bereavement stress during the prenatal and childhood periods and risk of psychosis in later life: population based cohort study.

OBJECTIVE: To examine the risk of psychosis associated with severe bereavement stress during the antenatal and postnatal period, between conception to adolescence, and with different causes of death. DESIGN: Population based cohort study. SETTING: Swedish national registers including births between 1973 and 1985 and followed-up to 2006. PARTICIPANTS: In a cohort of 1,045,336 Swedish births (1973-85), offspring born to mothers exposed to severe maternal bereavement stress six months before conception or during pregnancy, or exposed to loss of a close family member subsequently from birth to 13 years of age were followed until 2006. Admissions were identified by linkage to national patient registers. MAIN OUTCOME MEASURES: Crude and adjusted odds ratios for all psychosis, non-affective psychosis, and affective psychosis. RESULTS: Maternal bereavement stress occurring preconception or during the prenatal period was not associated with a significant excess risk of psychosis in offspring (adjusted odds ratio, preconception 1.24, 95% confidence interval 0.96 to 1.62; first trimester 0.95, 0.58 to 1.56; second trimester 0.79, 0.46 to 1.33; third trimester 1.14, 0.78 to 1.66). Risks increased modestly after exposure to the loss of a close family member from birth to adolescence for all psychoses (adjusted odds ratio 1.17, 1.04 to 1.32). The pattern of risk was generally similar for non-affective and affective psychosis. Thus estimates were higher after death in the nuclear compared with extended family but remained non-significant for prenatal exposure; the earlier the exposure to death in the nuclear family occurred in childhood (all psychoses: adjusted odds ratio, birth to 2.9 years 1.84, 1.41 to 2.41; 3-6.9 years 1.47, 1.16 to 1.85; 7-12.9 years 1.32, 1.10 to 1.58) and after suicide. Following suicide, risks were especially higher for affective psychosis (birth to 2.9 years 3.33, 2.00 to 5.56; 6.9 years 1.84, 1.04 to 3.25; 7-12.9 years 2.68, 1.84 to 3.92). Adjustment for key confounders attenuated but did not explain associations with risk. CONCLUSIONS: Postnatal but not prenatal bereavement stress in mothers is associated with an increased risk of psychosis in offspring. Risks are especially high for affective psychosis after suicide in the nuclear family, an effect that is not explained by family psychiatric history. Future studies are needed to understand possible sources of risk and resilience so that structures can be put in place to support vulnerable children and their families.

School performance and the risk of suicide attempts in young adults: a longitudinal population-based study.

BACKGROUND: Poor school performance is strongly associated with attempted suicide, but the mechanisms underlying this association are uncertain. We examined this relationship and the extent to which it is explained by (i) adult health behaviours and (ii) social conditions. Furthermore, we examined the potential modifying role of previous suicidal thoughts in the relationship. METHOD: We conducted a longitudinal cohort study of 6146 individuals aged 18-33 years, recruited in 2002 and 2006 in Stockholm and resurveyed in 2007 and 2010 respectively. We estimated the risk of reported lifetime suicide attempts at follow-up among individuals without a history of suicide attempts at baseline and in relation to compulsory school-leaving grades, controlling for possible confounders and mediators. RESULTS: There were 91 cases of self-reported suicide attempts during the follow-up (5-year incidence of 1.5%). ORs ranged from 3.35 [95% confidence interval (CI) 1.88-5.96] for those in the lowest grade quartile to 2.60 (95% CI 1.48-4.57) and 1.76 (95% CI 0.99-3.13) for those in the second and third quartiles respectively. The relationship between school performance and risk of suicide attempts did not differ by sex. Adult health behaviours and social conditions marginally attenuated, but did not explain, the relationship. The gradient varied with baseline history of suicidal thoughts, and was found only among individuals without such a history. CONCLUSIONS: Poor school performance was found to predict suicide attempts among young adults without a history of suicidal thoughts. Adult health behaviours and social conditions did not explain this relationship. Instead, other factors linked with poor school performance, such as poor coping ability, may increase the risk of suicide attempts.

Hearing and speech impairment at age 4 and risk of later non-affective psychosis.

BACKGROUND: Schizophrenia often becomes manifest in late adolescence and young adulthood but deviations in physical and behavioural development may already be present in childhood. We investigated the relationship between hearing impairment (measured with audiometry) and speech impairment (broadly defined) at age 4 years and adult risk of non-affective psychosis. METHOD: We performed a population-based, case­control study in Sweden with 105 cases of schizophrenia or other non-affective psychoses and 213 controls matched for sex, date and place of birth. Information on hearing and speech impairment at age 4, along with potential confounding factors, was retrieved from Well Baby Clinic (WBC) records. RESULTS: Hearing impairment [odds ratio (OR) 6.0, 95% confidence interval (CI) 1.6­23.2] and speech impairment (OR 2.6, 95% CI 1.4­4.9) at age 4 were associated with an increased risk of non-affective psychotic illness. These associations were mutually independent and not explained by parental psychiatric history, occupational class or obstetric complications. CONCLUSIONS: These results support the hypothesis that psychosis has a developmental aspect with presentation of antecedent markers early in childhood, long before the disease becomes manifest. Our findings add to the growing evidence that early hearing impairment and speech impairment are risk indicators for later non-affective psychosis and possibly represent aetiological clues and potentially modifiable risk factors. Notably, speech impairment and language impairment are both detectable with inexpensive, easily accessible screening.

Recent time trends in levels of self-reported anxiety, mental health service use and suicidal behaviour in Stockholm.

OBJECTIVE: To investigate recent time trends in several indicators of mental ill-health and the patterning of these indicators between genders and younger vs. older individuals in Stockholm County. METHOD: Several indicators were used; self-reported anxiety from the Swedish Survey of Living Conditions, information on psychiatric in-patient and out-patient care, attempted and completed suicides from national and regional registers. Gender- and age-specific trends were compared for the time period of 1997-2006. RESULTS: Self-reported anxiety and psychiatric service use increased among young individuals of both genders, while attempted suicides increased only among young women. By contrast, these indicators decreased or remained stable in the older age group from year 2001 and onwards. CONCLUSION: Our data indicate a rising, and highly prevalent, mental ill-health among the young in Stockholm County, a region representative of urbanized, secular Western societies.

Use of snus and risk for cardiovascular disease: results from the Swedish Twin Registry.

OBJECTIVE: To study the association between snus use and the risk for cardiovascular disease, i.e. ischemic heart disease and stroke. DESIGN: Cohort study. SETTING: Sweden. SUBJECTS: Sixteen thousand six hundred and forty-two male Swedish twins participating in the Screening Across the Lifespan Twin Study, conducted in 1998- 2002, were followed for incident cardiovascular disease. Participants were without a history of cardiovascular disease at baseline and incident cases were identified via the Swedish Cause of Death Register and Hospital Discharge Register. RESULTS: Overall, there was no association between use of snus and risk for cardiovascular disease. Current snus users, without a smoking history, had a relative risk of 1.00 (95% confidence interval 0.69-1.46) for cardiovascular disease as compared to non users. Corresponding relative risks for ischemic heart disease and stroke were 0.85 (95% confidence interval 0.51-1.41) and 1.18 (95% confidence interval 0.67-2.08), respectively. In smoking adjusted models, risk estimates for ischemic heart disease in relation to snus use were all close to unity regardless of timing or intensity of snus use. However, current heavy snus users (consuming more than four cans week(-1)) had a relative risk for stroke of 1.75 (95% confidence interval 0.95-3.21). CONCLUSION: These data do not support any strong association between snus use and risk for cardiovascular disease.

Cigarette smoking and breast cancer risk: a population-based study in Sweden.

In a Swedish population-based case-control study, smoking showed no convincing association with risk of postmenopausal breast cancer - regardless of timing or level of smoking exposure - either overall or among subgroups.