Congestive heart failure (CHF) is a serious complication in patients with atrial fibrillation (AF).
To study associations between relevant co-morbidities and CHF in patients with AF.
Study population included all adults (n=12,283) =45 years diagnosed with AF at 75 primary care centers in Sweden 2001-2007. Logistic regression was used to calculate odds ratios with 95% confidence intervals (CIs) for the associations between co-morbidities, and prevalent CHF. In a subsample (n=9424), (excluding patients with earlier CHF), Cox regression was used to estimate hazard ratios with 95% CIs for the association between co-morbidities, and a first hospital diagnosis of CHF, after adjustment for age and socio-economic factors.
During 5.4 years' follow-up (standard deviation 2.5), 2259 patients (24.0%; 1135 men, 21.8%, and 1124 women, 26.7%) were diagnosed with CHF. Patients with hypertension were less likely to have CHF, while a diagnosis of coronary heart disease, valvular heart disease, diabetes, or chronic obstructive pulmonary disease (COPD), was consistently associated with CHF among men and women. CHF was more common among women with depression. The relative fully adjusted risk of incident CHF was increased for the following diseases in men with AF: valvular heart disease, cardiomyopathy, and diabetes; and for the following diseases in women: valvular heart disease, diabetes, obesity, and COPD. The corresponding risk was decreased among women for hypertension.
In this clinical setting we found hypertension to be associated with a decreased risk of CHF among women; valvular heart disease and diabetes to be associated with an increased risk of CHF in both sexes; and cardiomyopathy to be associated with an increased risk of CHF among men.
Many studies have addressed the question of whether mental disorder is associated with creativity, but high-quality epidemiological evidence has been lacking.AimsTo test for an association between studying a creative subject at high school or university and later mental disorder.
In a case-control study using linked population-based registries in Sweden (N = 4 454 763), we tested for associations between tertiary education in an artistic field and hospital admission with schizophrenia (N = 20 333), bipolar disorder (N = 28 293) or unipolar depression (N = 148 365).
Compared with the general population, individuals with an artistic education had increased odds of developing schizophrenia (odds ratio = 1.90, 95% CI = [1.69; 2.12]) bipolar disorder (odds ratio = 1.62 [1.50; 1.75]) and unipolar depression (odds ratio = 1.39 [1.34; 1.44]. The results remained after adjustment for IQ and other potential confounders.
Students of artistic subjects at university are at increased risk of developing schizophrenia, bipolar disorder and unipolar depression in adulthood.Declaration of interestNone.
Invasive dental treatment is suggested to be associated with an increased risk for the development of cardiovascular events. We tested the hypothesis that the incidence of a first myocardial infarction (MI) within 4 wk after invasive dental treatments is increased. A registry-based case-control study within nationwide health care and population registries in Sweden was performed. The case patients included 51,880 individuals with a first fatal or nonfatal MI between January 2011 and December 2013. For each case, 5 control subjects, free from prior MI and matched for age, sex, and geographic area of residence, were randomly selected from the national population registry through risk set sampling with replacement, resulting in 246,978 control subjects. Information on dental treatments was obtained from the Dental Health Register, and the procedures were categorized into invasive dental treatments or other dental treatments. Conditional logistic regression was used to estimate odds ratios (ORs) for MI with corresponding 95% confidence intervals (CIs). In addition to the matching variables, adjustments were made for the following confounders: diabetes, previous cardiovascular disease (CVD), CVD drug treatment, education, and income. The mean age for case patients and controls subjects was 72.6 ± 13.0 y and 72.3 ± 13.0 y, respectively. Case patients more often had previous CVD (49% vs. 23%; P
Different abdominal symptoms may signal cancer, but their role is unclear.
To examine associations between abdominal symptoms and subsequent cancer diagnosed in the abdominal region.
Prospective cohort study comprising 493 GPs from surgeries in Norway, Denmark, Sweden, Scotland, Belgium, and the Netherlands.
Over a 10-day period, the GPs recorded consecutive consultations and noted: patients who presented with abdominal symptoms pre-specified on the registration form; additional data on non-specific symptoms; and features of the consultation. Eight months later, data on all cancer diagnoses among all study patients in the participating general practices were requested from the GPs.
Consultations with 61 802 patients were recorded and abdominal symptoms were documented in 6264 (10.1%) patients. Malignancy, both abdominal and non-abdominal, was subsequently diagnosed in 511 patients (0.8%). Among patients with a new cancer in the abdomen (n = 251), 175 (69.7%) were diagnosed within 180 days after consultation. In a multivariate model, the highest sex- and age-adjusted hazard ratio (HR) was for the single symptom of rectal bleeding (HR 19.1, 95% confidence interval = 8.7 to 41.7). Positive predictive values of >3% were found for macroscopic haematuria, rectal bleeding, and involuntary weight loss, with variations according to age and sex. The three symptoms relating to irregular bleeding had particularly high specificity in terms of colorectal, uterine, and bladder cancer.
A patient with undiagnosed cancer may present with symptoms or no symptoms. Irregular bleeding must always be explained. Abdominal pain occurs with all types of abdominal cancer and several symptoms may signal colorectal cancer. The findings are important as they influence how GPs think and act, and how they can contribute to an earlier diagnosis of cancer.
Limited studies have examined red meat consumption in relation to risk of chronic obstructive pulmonary disease (COPD), and none have examined the impact of long-term diet on COPD risk. We sought to investigate the association between long-term red meat consumption and risk of COPD.
The population-based prospective Swedish Mammography Cohort included 34,053 women, aged 48-83 years, followed for the current analyses from 2002 to 2014. Unprocessed and processed red meat consumption was assessed with a self-administered questionnaire in 1987 and 1997. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
Over a mean follow-up of 11.6 years (2002-2014; 393,831 person-years), 1488 COPD cases were ascertained via linkage to the Swedish health registers. A positive association between long-term processed red meat (average from 1987 to 1997) and risk of COPD was observed. In contrast, no association was observed with unprocessed red meat with corresponding HRs of 1.36 (95% CI 1.03-1.79) for processed and 0.87 (95% CI 0.74-1.02) for unprocessed red meat among women who consumed =?50 g/day compared to
The impact of childhood obesity on the Swedish Health Care system is described. Childhood Obesity and Diabetes Type 2 is increasing for the last 10 years, but not Diabetes Type 1. Thus, prevention is needed. How to define prevention of obesity? Could treatment of childhood obesity be regarded as prevention of adult obesity? Of course it could, but we are lacking a long term follow-up from childhood to adulthood. However, we know that childhood obesity is a risk factor for adult disease. But we need long-lasting results in children to being able to state that we have prevented adult obesity. What about treatment of children with overweight, i.e. defined as the less severe level of an increased body weight as opposed to obesity? There are few if any studies restricting the treatment only to overweight children. Normally, obese children are treated, and some overweight children are added usually to increase the study sample. Then of course promotion of a healthy lifestyle could be of major interest. Finally, the traditional concept of primary prevention seems to be the only solution that is realistic according to many. However, there is no clear pattern when primary prevention works.
Myocardial infarction with non-obstructive coronary arteries is a working diagnosis for several heart disorders. Previous studies on anxiety and depression in patients with myocardial infarction with non-obstructive coronary arteries are lacking. Our aim was to investigate the prevalence of anxiety and depression among patients with myocardial infarction with non-obstructive coronary arteries.
We included 99 patients with myocardial infarction with non-obstructive coronary arteries together with age- and sex-matched control groups who completed the Beck Depression Inventory and the Hospital Anxiety and Depression Scale (HADS) 3 months after the acute event.
Using the Beck Depression Inventory, we found that the prevalence of depression in patients with myocardial infarction with non-obstructive coronary arteries (35%) was higher than in healthy controls (9%; P = .006) and similar to that of patients with coronary heart disease (30%; P = .954). Using the HADS anxiety subscale, we found that the prevalence of anxiety in patients with myocardial infarction with non-obstructive coronary arteries (27%) was higher than in healthy controls (9%; P = .002) and similar to that of patients with coronary heart disease (21%; P = .409). Using the HADS depression subscale, we found that the prevalence of depression in patients with myocardial infarction with non-obstructive coronary arteries (17%) was higher than in healthy controls (4%; P = .003) and similar to that of patients with coronary heart disease (13%; P = .466). Patients with myocardial infarction with non-obstructive coronary arteries and takotsubo syndrome scored higher on the HADS anxiety subscale than those without (P = .028).
This is the first study on the mental health of patients with myocardial infarction with non-obstructive coronary arteries to show that prevalence rates of anxiety and depression are similar to those in patients with coronary heart disease.
Background: Hip fractures affect 1.6 million patients yearly worldwide, often elderly with complex comorbidity. Mortality following surgery for acute hip fracture is high and multifactorial; high age, comorbidities and complication/deterioration in health following surgery. Whether the anaesthesia technique affects the 30-day mortality rate has been studied widely without reaching a consensus. The primary aim of this study was to determine anaesthetic techniques used in Sweden and their impact on the 30-day mortality rate in elderly undergoing acute hip fracture surgery. Other aims were to study the impact of age, gender, ASA class, fracture type and delay in surgery on the 30-day mortality rate. Methods: Data from 13,649 patients =50 years old who had undergone acute hip fracture surgery and been reported to Swedish perioperative register (SPOR) between 2016 and 2017 were analysed. Results: The most commonly used anaesthetic technique was neuraxial anaesthesia (NA; 11,257, 82%), followed by general anaesthesia (GA; 2,190, 16%) and combined general and neuraxial anaesthesia (CA; 202, 1.5%) out of the 13,649 studied. The 30-day mortality rate was 7.7% for the entire cohort; GA 7.8%, NA 7.7% and CA 7.4%. Mortality was higher in elderly patients, those with a high ASA class, pertrochanteric fracture and males. Conclusions: The present study showed that NA is by far the most common anaesthetic technique for acute hip fracture surgery in Sweden. However, the anaesthetic technique used during this type of surgery had no impact on the 30-day mortality rate in patients. Increasing age, ASA class and male gender increased the 30-day mortality.
Although previous studies examining leukocyte telomere length (LTL) and all-cause mortality controlled for several confounders, the observed association could be biased due to unmeasured confounders, including familial factors. We aimed to examine the association of LTL with all-cause mortality in a Swedish twin sample while adjusting for familial factors and allowing for time-dependent effects. A total of 366 participants (174 twin pairs and 18 individuals) were recruited from the Swedish Twin Registry. LTL was assessed using the Southern blot method. All-cause mortality data were obtained through linkage with the Swedish Population Registry, updated through November 15, 2017. To control for familial factors within twin pairs, we applied a between-within shared frailty model based on generalized survival models. Overall, 115 (31.4%) participants were men and 251 (68.6%) were women. The average age of the study participants when blood was drawn was 79.1 years, and follow-up duration ranged from 10 days to 25.7 years (mean = 10.2 years). During the follow-up period, 341 (93.2%) participants died. Shorter LTL was associated with higher mortality rates when controlling for familial factors in the between-within shared frailty model. We found significant time-dependent effects of LTL on all-cause mortality, where the mortality rate ratios were attenuated with increasing age.
Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden. Department of Surgery, Eskilstuna County Hospital, Eskilstuna, Sweden. Center for Clinical Research Sörmland, Uppsala University, Uppsala, Sweden. Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Department of Surgery, Västerås County Hospital, Västerås, Sweden.
Acute pancreatitis is linked to pancreatic cancer, but the direction of this association is not fully elaborated.
This was a population-based cohort study including all Swedish residents diagnosed with a first-time episode of acute pancreatitis between 1997 and 2013 and corresponding matched pancreatitis-free individuals from the general population. Hazard ratios for the association between acute pancreatitis and pancreatic cancer were estimated using multivariable Cox regression models.
Overall, 49,749 individuals with acute pancreatitis and 138,750 matched individuals without acute pancreatitis were followed up for 1,192,134 person-years (median 5.3 years). A total of 769 individuals developed pancreatic cancer, of whom 536 (69.7%) had a history of acute pancreatitis. The risk of pancreatic cancer was substantially increased during the first few years after a diagnosis of acute pancreatitis but declined gradually over time, reaching a level comparable to the pancreatitis-free population after >10 years of follow-up. In those with non-gallstone-related acute pancreatitis, the risk of pancreatic cancer declined to a level comparable to the pancreatitis-free population only when follow-up time was censored for a second episode of acute pancreatitis or a diagnosis of chronic pancreatitis. Increasing number of recurrent episodes of acute pancreatitis was associated with increased risk of pancreatic cancer.
These findings imply a delay in the diagnosis of pre-existing pancreatic cancer, if clinically presented as acute pancreatitis. Any association between non-gallstone-related acute pancreatitis and pancreatic cancer in the long-term (>10 years) could be mediated through recurrent acute pancreatitis or chronic pancreatitis.
Epidemiological data indicate decreased risk for development and growth of abdominal aortic aneurysm (AAA) among patients with diabetes mellitus (DM), but DM also goes with increased cardiovascular (CV) morbidity and mortality. We evaluated the effects of DM on mortality and CV morbidity after elective open AAA repair.
This is a nationwide observational cohort study of patients registered in the Swedish Vascular Registry and the Swedish National Diabetes Register. Comparison of mortality and CV morbidity after elective open AAA repair in 397 patients with and 1709 without DM with propensity score-adjusted analysis, during median 4.51 years of follow-up for patients with DM and 4.59 years for those without.
In adjusted analysis, diabetic patients showed higher rates of acute myocardial infarction (AMI) (relative risk [RR] 1.57, 95% confidence interval [CI] 1.04-2.36; P = 0.03) and major adverse cardiovascular events (MACEs, RR 1.28, CI 1.04-1.58; P = 0.02) during follow-up, whereas there were no differences in total (RR 0.98, CI 0.75-1.29; P = 0.91) or CV (RR 0.30, CI 0.07-1.26; P = 0.10) mortality or stroke (RR 1.06, CI 0.67-1.67; P = 0.80). Among diabetic patients, higher HbA1c was related to a higher risk for AMI during follow-up (RR 1.04, CI 1.01-1.08; P = 0.02).
Patients with DM had higher rates of AMI and MACE after elective open AAA repair than those without DM, whereas neither total nor CV mortality differed between groups. Putative beneficial effects of DM on the aortic wall might not be relevant after open surgery including thrombus removal and aneurysmorrhaphy.
Understanding the impact of obesity on premature mortality is critical, as obesity has become a global health issue.
To contrast the relationship between body mass index (BMI) and premature death (all-cause; circulatory causes) in New York State (USA) and Northern Sweden.
Baseline data were obtained between 1989 and 1999 via questionnaires (USA) and health exams (Sweden), with mortality data from health departments, public sources (USA) and the Swedish Death Register. Premature death was death before life expectancy based on sex and year of birth. Within country and sex, time to premature death was compared across BMI groups (18.5-24.9 kg/m2 (reference), 25-29.9 kg/m2, 30.0-34.9 kg/m2, =35.0 kg/m2) using Proportional Hazards regression. Absolute risk (deaths/100,000 person-years) was compared for the same stratifications among nonsmokers.
60,600 Swedish (47.8% male) and 31,198 US subjects (47.7% male) were included. Swedish males with BMI=30 had increased hazards (HR) of all-cause premature death relative to BMI 18.5-24.9 (BMI 30-34.9, HR = 1.71 (95% CI: 1.44, 2.02); BMI=35, HR = 2.89 (2.16, 3.88)). BMI=25 had increased hazards of premature circulatory death (BMI 25-29.9, HR = 1.66 (1.32, 2.08); BMI 30-34.9, HR = 3.02 (2.26, 4.03); BMI=35, HR = 4.91 (3.05, 7.90)). Among US males, only BMI=35 had increased hazards of all-cause death (HR = 1.63 (1.25, 2.14)), while BMI 30-34.9 (HR = 1.83 (1.20, 2.79)) and BMI=35 (HR = 3.18 (1.96, 5.15)) had increased hazards for circulatory death. Swedish females showed elevated hazards with BMI=30 for all-cause (BMI 30-34.9, HR = 1.42 (1.18, 1.71) and BMI=35, HR = 1.61 (1.21, 2.15) and with BMI=35 (HR = 3.11 (1.72, 5.63)) for circulatory death. For US women, increased hazards were observed among BMI=35 (HR = 2.10 (1.60, 2.76) for all-cause and circulatory HR = 3.04 (1.75, 5.30)). Swedish males with BMI=35 had the highest absolute risk of premature death (762/100,000 person-years).
This study demonstrates a markedly increased risk of premature death associated with increasing BMI among Swedish males, a pattern not duplicated among females.
Background: Previous Swedish studies have shown a social gradient on paediatric care for viral gastroenteritis. Aim: To study the effect of a free rotavirus vaccine programme on hospital care for viral gastroenteritis. Method: A register-based national cohort study of paediatric in- and outpatient care for viral gastroenteritis in children
Radical prostatectomy (RP) is a common surgical procedure with a risk of postoperative erectile dysfunction and urinary incontinence. There is a need for data on RP as a basis for quality assurance and benchmarking.
In 2015, prostatectomies in Sweden (PiS) form was implemented in the National Prostate Cancer Register (NPCR) of Sweden with data on pre-, peri- and post-operative variables.
Out of all radical prostatectomies performed in 2016 in Sweden, 3096/3881 (80%) were registered in PiS. A total of 2605 (84%) were robot-assisted radical prostatectomy (RARP) and 491 (16%) were RRP (retropubic radical prostatectomy). RARP was performed by 91 surgeons of whom 47% operated more than 25 RP/year; and RRP was performed by 69 surgeons of whom 10% performed more than 25 RP/year. RARP had a longer operative time (median operating time: RARP 155?minutes [IQR 124-190]; RRP 129?minutes [IQR 105-171]; P?
The contribution of different income sources from work and social benefits to trajectories of income for the parents of children with cancer has not been empirically investigated.
Using Swedish registers, parents of children with an incidence cancer diagnosis between 2004 and 2009 were identified and matched with parents of children without cancer (reference parents). A total of 20,091 families were followed from the year before the diagnosis to a maximum of 8 years. Generalized linear models estimated the ratios of mean incomes from work and social benefits and of its total.
Around the time of the child's cancer diagnosis, the total income was on average up to 6% higher among the mothers of children with cancer compared with reference mothers, but no differences were noted among fathers. Income from work dropped to the lowest level around the time of a cancer diagnosis, with swift recovery noted for fathers but not for mothers. Sickness and childcare-related benefits were up to 6 times larger for the parents of children with cancer than reference parents. As social benefits diminished after approximately 3 years, the total income of mothers of children with cancer became lower than that of reference mothers, and the gap widened over time.
ISGlobal, Barcelona Institute for Global Health - Campus MAR, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain. Electronic address: email@example.com.
We integratively assessed the effect of different indoor and outdoor environmental exposures early in life on respiratory and allergic health conditions among children from (sub-) urban areas.
This study included children participating in four ongoing European birth cohorts located in three different geographical regions: INMA (Spain), LISAplus (Germany), GINIplus (Germany) and BAMSE (Sweden). Wheezing, bronchitis, asthma and allergic rhinitis throughout childhood were assessed using parental-completed questionnaires. We designed "environmental scores" corresponding to different indoor, green- and grey-related exposures (main analysis, a-priori-approach). Cohort-specific associations between these environmental scores and the respiratory health outcomes were assessed using random-effects meta-analyses. In addition, a factor analysis was performed based on the same exposure information used to develop the environmental scores (confirmatory analysis, data-driven-approach).
A higher early exposure to the indoor environmental score increased the risk for wheezing and bronchitis within the first year of life (combined adjusted odds ratio: 1.20 [95% confidence interval: 1.13-1.27] and 1.28 [1.18-1.39], respectively). In contrast, there was an inverse association with allergic rhinitis between 6 and 8 years (0.85 [0.79-0.92]). There were no statistically significant associations for the outdoor related environmental scores in relation to any of the health outcomes tested. The factor analysis conducted confirmed these trends.
Although a higher exposure to indoor related exposure through occupants was associated with an increased risk for wheezing and bronchitis within the 1st year, it might serve as a preventive mechanism against later childhood allergic respiratory outcomes in urbanized environments through enhanced shared contact with microbial agents.
To determine the prevalence of various environmental intolerances (EIs), using several criteria in a Swedish and a Finnish general population. Ill-health attributed to low-level environmental exposures is a commonly encountered challenge in occupational and environmental medicine.
In population-based questionnaire surveys, the Västerbotten Environmental Health Study (Sweden) and the Österbotten Environmental Health Study (Finland), EI was inquired by one-item questions on symptom attribution to chemicals, certain buildings, or electromagnetic fields (EMFs), and difficulties tolerating sounds. The respondents were asked whether they react with central nervous system (CNS) symptoms or have a physician-diagnosed EI attributed to the corresponding exposures. Prevalence rates were determined for different age and sex groups and the Swedish and Finnish samples in general.
In the Swedish sample (n = 3406), 12.2% had self-reported intolerance to chemicals, 4.8% to certain buildings, 2.7% to EMFs, and 9.2% to sounds. The prevalence rates for the Finnish sample (n = 1535) were 15.2%, 7.2%, 1.6%, and 5.4%, respectively, differing statistically significantly from the Swedish. EI to chemicals and certain buildings was more prevalent in Finland, while EI to EMFs and sounds more prevalent in Sweden. The prevalence rates for EI with CNS-symptoms were lower and physician-diagnosed EIs considerably lower than self-reported EIs. Women reported EI more often than men and the young (18-39 years) to a lesser degree than middle-aged and elderly.
The findings reflect the heterogeneous nature of EI. The differences in EI prevalence between the countries might reflect disparities concerning which exposures people perceive harmful and focus their attention to.
Rates of drug abuse are higher among divorced individuals than among those who are married, but it is not clear whether divorce itself is a risk factor for drug abuse or whether the observed association is confounded by other factors. We examined the association between divorce and onset of drug abuse in a population-based Swedish cohort born during 1965-1975 (n = 651,092) using Cox proportional hazards methods, with marital status as a time-varying covariate. Potential confounders (e.g., demographics, adolescent deviance, and family history of drug abuse) were included as covariates. Parallel analyses were conducted for widowhood and drug-abuse onset. In models with adjustments, divorce was associated with a substantial increase in risk of drug-abuse onset in both sexes (hazard ratios > 5). Co-relative analyses (among biological relatives) were consistent with a partially causal role of divorce on drug-abuse onset. Widowhood also increased risk of drug-abuse onset, although to a lesser extent. Divorce is a potent risk factor for onset of drug abuse, even after adjusting for deviant behavior in adolescence and family history of drug abuse. The somewhat less-pronounced association with widowhood, particularly among men, suggests that the magnitude of association between divorce and drug abuse may not be generalizable to the end of a relationship.
With the development of several 'vein-to-vein' databases, which capture data on the entire donor-recipient continuum and link this data to health outcomes, there has been an increasing number of studies investigating the health effects of all aspects of the practice of transfusion medicine. The Scandinavian Donations and Transfusions (SCANDAT) database is one of several such databases, which includes all electronically available data on blood donors, donations and transfusions since the late 1960s in Sweden and the early 1980s in Denmark. The SCANDAT database has been used to characterise disease occurrence among blood donors and transfused patients, as well as to investigate possible health effects of blood donations, aspects of transfusion care and possible transfusion transmission of disease. Recent publications include studies on recipient mortality associated with the storage lesion, studies on the effects of donor demographics on patient mortality and health effects of frequent blood donation. Although this research approach is clearly very powerful, the appropriate analysis of such real-world data is complex and requires close methodological attention. The purpose of this review is to present some of the research conducted within the SCANDAT collaboration. We hope more international collaboration may help improve our understanding of the important remaining questions about donor and recipient health.
There is growing interest in exposures prior to conception as possible risk factors for offspring asthma. Although partially supported by evidence from limited human studies, current evidence is inconsistent and based on recall of exposure status.
We aimed to investigate grandmaternal smoking during pregnancy and the risk of asthma in grandchildren using prospectively collected population-based data.
Information on grandmaternal and maternal smoking during pregnancy and grandchild use of asthma medications was collected from national Swedish registries. Associations between grandmaternal smoking during pregnancy (10-12 weeks) and asthma medication use in grandchildren were investigated using generalized estimating equations. Ages at which asthma medications were prescribed classified childhood asthma into never, early transient (0-3 years), late onset (3-6 years) and early persistent (0-3 and 3-6 years) phenotypes.
From 1982 to 1986, 44 583 grandmothers gave birth to 46 197 mothers, who gave birth to 66 271 grandchildren (born 1996-2010). Children aged 1-6 years had an increased asthma risk if their grandmothers had smoked during pregnancy, with a higher risk for more exposure (10+ cigs/d; adjusted OR 1.23; 1.17, 1.30). Maternal smoking did not modify this relationship.
Children had an increased risk of asthma in the first 6 years of life if their grandmothers smoked during early pregnancy, independent of maternal smoking. Importantly, this exhibited a dose-response relationship and was associated with a persistent childhood asthma phenotype. These findings support possible epigenetic transmission of risk from environmental exposures in previous generations.