Electrocardiographic parameters and the risk of new-onset atrial fibrillation in the general population

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): The Rotterdam Study is funded by Erasmus Medical Center and Erasmus University, Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw), the Research Institute for Diseases in the Elderly (RIDE), the Ministry of Education, Culture and Science, the Ministry for Health, Welfare and Sports, the European Commission (DG XII), and the Municipality of Rotterdam. This study is further supported by the Senior Scientist Grant from Dutch Heart Foundation (03-004-2021-T050).

Background

The (shape of the) association and sex-differences between electrocardiographic parameters and new-onset atrial fibrillation (AF) remain incompletely understood.

Purpose

To investigate the association between electrocardiographic parameters and new-onset atrial fibrillation among men and women in the general population.

Methods

12,212 participants free of AF from a large population-based cohort study were included. Up to five repeated measurements of electrocardiographic parameters including PR, QRS, QT, QT corrected for heart rate (QTc), JT, RR interval, and heart rate were assessed at baseline and follow-up examinations. Cox proportional hazards models and joint models, both adjusted for cardiovascular risk factors, were used to determine the (shape of) association between baseline and longitudinal electrocardiographic parameters with new-onset AF. Additionally, we evaluated potential sex-differences.

Results

During a median follow-up of 9.3 years, 1,282 incident AF cases occurred among 12,212 participants (mean age 64.9 years, 58.2% women). Penalized cubic splines revealed that associations between baseline electrocardiographic measures and risk of new-onset AF were generally U-shaped (Figure 1). Sex-differences in terms of the shape of the various associations were most apparent for baseline PR, QT, QTc, RR, and heart rate in relation to new-onset AF. Longitudinal measures of PR (hazard ratio (HR), 95% confidence interval (CI), 1.43, 1.02-2.04, p=0.0393), and QTc interval (HR, 95% CI, 5.23, 2.18-12.45, p=0.0002) were significantly associated with new-onset AF. Sex-stratified analyses showed that the longitudinal associations were more prominent among men.

Conclusions

Baseline electrocardiographic measures and risk of new-onset AF were generally U-shaped. Longitudinal electrocardiographic measures of PR, and QTc interval were significantly associated with new-onset AF, more pronounced in men. Our findings imply that different thresholds of electrocardiographic parameters might translate to a differential risk of AF among men and women, and that treatment options targeting specific electrocardiographic parameters might prevent AF in the general population, in particular in men.

Heart rate variability and atrial fibrillation in the general population: a longitudinal and mendelian randomization study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): The Rotterdam Study is funded by Erasmus Medical Center and Erasmus University, Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw), the Research Institute for Diseases in the Elderly (RIDE), the Ministry of Education, Culture and Science, the Ministry for Health, Welfare and Sports, the European Commission (DG XII), and the Municipality of Rotterdam. This study is further supported by the Gender and prevention grant (555003017) from ZonMw.

Background

Sex-differences and the causality of the association between heart rate variability (HRV) and atrial fibrillation (AF) remain unclear.

Purpose

To investigate the sex-differences and the causality of the association between heart rate variability and atrial fibrillation.

Methods

12,334 participants free of AF from a large population-based cohort study were included. Measures of HRV including the standard deviation of normal RR-intervals (SDNN), SDNN corrected for heart rate (SDNNc), RR-interval differences (RMSSD), RMSSD corrected for heart rate (RMSSDc), and heart rate were assessed at baseline and follow-up examinations. Joint models, adjusted for cardiovascular risk factors, were used to determine the association between longitudinal measures of HRV with new-onset AF. Additionally, we evaluated sex-differences. Genetic variants for HRV were used as instrumental variables in a Mendelian randomization (MR) analysis using GWAS summary-level data.

Results

During a median follow-up of 9.4 years, 1,302 incident AF cases occurred. In joint models, higher SDNN (hazard ratio (HR), 95% confidence interval (CI), 1.24, 1.04-1.47, p=0.0213), and higher RMSSD (HR, 95% CI, 1.33, 1.13-1.54, p=0.0010) were significantly associated with new-onset AF. Sex-stratified analyses showed that the associations were mostly prominent among women. In MR analyses, genetically determined decreases in SDNN (odds ratio (OR), 95% CI, 1.60, 1.27-2.02, p=8.36x10-05), and RMSSD (OR, 95% CI, 1.56, 1.31-1.86, p= 6.32x10-07) were significantly associated with increased AF risk.

Conclusions

Longitudinal measures of uncorrected HRV were significantly associated with new-onset AF, in particular among women. MR analyses supported the causal relationship between uncorrected measures of HRV with AF. Our findings indicate that measures to modulate HRV might prevent AF in the general population, especially among women.

Disentangling the association between kidney function and atrial fibrillation: a bidirectional Mendelian randomization study

Background

Observational studies suggest that kidney function and atrial fibrillation (AF) are bidirectionally associated. Whether this bidirectional association is causal remains unclear.

Purpose

To investigate the causality of the bidirectional association between kidney function and AF.

Methods

Genetic variants associated with different measures of kidney function including estimated glomerular filtration rate (eGFR) based on creatinine (eGFRcreat), blood urea nitrogen (BUN), chronic kidney disease (CKD, eGFR <60ml/min/1.73m2), eGFR based on cystatin (eGFRcys), urine albumin-to-creatinine ratio (UACR) and microalbuminuria (MA, UACR >30mg/g) were retrieved from multiple Genome-Wide Association Studies (GWAS). These GWAS were all part of the Chronic Kidney Disease Genetics (CKDGen) Consortium (n=24,063–1,040,070). Genetic variants associated with AF were retrieved from a GWAS on AF (n=1,030,836). We used two-sample MR analyses to assess the potential causality of the bidirectional association between kidney function and AF.

Results

MR analyses supported a causal effect of genetically predicted BUN, CKD and MA on AF risk (for BUN: n=18 SNPs, outlier corrected odds ratio (OR): 2.05, per 1 unit increase of BUN (mg/dL), 95% CI: 1.30–3.25, p-value = 2.13E-03. For CKD: n=9 SNPs, outlier corrected OR: 1.10, 95% CI: 1.04–1.17, p-value = 1.97E-03. For MA: n=5 SNPs, outlier corrected OR: 1.26, 95% CI: 1.10–1.46, p-value = 1.38E-03). MR analyses also supported a causal effect of genetically predicted AF on eGFRcreat (n=97 SNPs, outlier corrected OR: 0.998, per 1 unit increase of log transformed eGFRcreat (ml/min/1.73m2), 95% CI: 0.997–0.999, p-value = 6.78E-03), CKD risk (n=107 SNPs, outlier corrected OR: 1.06, 95% CI: 1.03–1.09, p-value = 2.97E-04) and MA risk (n=83 SNPs, outlier corrected OR: 1.07, 95% CI: 1.04–1.09, p-value = 2.49E-08). A suggestive causal effect of genetically predicted AF on eGFRcys was found (n=103 SNPs, outlier corrected OR: 0.993, per 1 unit increase of log transformed eGFRcys (ml/min/1.73m2), 95% CI: 0.986–0.999, p-value = 4.60E-02). MR analyses did not support a significant causal effect of the other kidney function measures on AF risk and vice versa. Moreover, sensitivity analyses, including weighted median estimator (WME), MR-Egger and the MR pleiotropy residual sum and outlier test (MR-PRESSO) indicated that these findings were robust. Furthermore, the associations did not change when genetic variants associated with coronary artery disease and heart failure were excluded.

Conclusions

MR analyses supported a bidirectional causal association between kidney function and AF. Our findings carry the potential for identification of important therapeutic targets for both conditions with implications for secondary prevention.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Erasmus Medical Center and Erasmus University, Rotterdam Forest plot with the MR effect estimatesBidirectional MR: Kidney function and AF

The Obesity Paradox in Lung Cancer: Associations With Body Size Versus Body Shape

Background

The association between obesity and lung cancer (LC) remains poorly understood. However, other indices of obesity on the basis of body shape instead of body size have not been examined yet. The aim of this study was to evaluate the association between different indices of body size and body shape and the risk of LC. In particular, this study examined the association between A Body Shape Index, a more precise indicator of abdominal fat than traditional anthropometric measures, and the risk of LC.

Methods

In the prospective cohort the Rotterdam Study, we analysed data of 9,689 participants. LC diagnoses were based on medical records and anthropometric measurements were assessed at baseline. Cox-regression analyses with corresponding Hazard Ratios were used to examine the association between the anthropometric measurements and the risk of LC with adjustment for potential confounders. Potential non-linear associations were explored with cubic splines using the Likelihood ratio (LR) test.

Results

During follow-up, 319 participants developed LC. Body mass Index (BMI) was inversely associated with the risk of lung cancer (HR 0.94, 95% CI: 0.91–0.97) and persisted after excluding lung cancer cases during the first 10 years of follow-up. There was evidence for a non-linear association between BMI and the risk of lung cancer (0,04, df = 1), which indicated that the inverse association between BMI and lung cancer was mainly present in non-obese participants. Waist circumference (WC) (HR 1.03 95% CI: 1.01–1.05), Waist-to-Hip Ratio (WHR) (HR 1.23 95% CI: 1.09–1.38) and ABSI (A Body Shape Index) (HR 1.17 95% CI: 1.05–1.30) were positively and linearly associated with the risk of lung cancer.

Conclusions

Body shape rather than body size may be an important risk indicator of LC. Future research should focus on the role of visceral fat and the risk of LC as well as the underlying mechanisms.

Aortic Arch Calcification and the Risk of Cancer: A Population-Based Cohort Study

Background: Atherosclerosis and cancer share multiple disease pathways. Yet, it is unclear if atherosclerosis is associated with a subsequent higher cancer risk. We determined the association of atherosclerotic calcification in the aortic arch, as proxy for systemic atherosclerosis, with the risk of cancer.

Methods: Between 2003 and 2006, 2,404 participants (mean age: 69.5 years, 52.5% women) from the prospective population-based Rotterdam Study underwent computed tomography to quantify calcification in the aortic arch. Participants were followed for the onset of cancer, death, loss to follow-up, or January 1st, 2015, whichever came first. We computed sex-specific tertiles of aortic arch calcification volumes. Next, we examined the association between the volume and severity (i.e., tertiles) of aortic arch calcification and the risk of cancer using Cox proportional hazard models.

Results: During a median (interquartile range) follow-up of 9.6 years (8.9–10.5), 348 participants were diagnosed with cancer. Participants with the greatest severity of aortic arch calcification had a higher risk of cancer [hazard ratio for the third tertile compared to the first tertile of aortic arch calcification volume in the total population is 1.39 (95% CI = 1.04–1.86)].

Conclusions: Individuals with the most severe aortic arch calcification had a higher risk of cancer. While this could reflect the impact of long-term exposure to shared risk factors, it might also point toward the co-occurrence of both conditions.

Higher Plasma Amyloid-β Levels Are Associated with a Higher Risk of Cancer: A Population-Based Prospective Cohort Study

BACKGROUND

Various studies show an inverse relation between Alzheimer disease and cancer, but findings are likely to be biased by surveillance and survival bias. Plasma amyloid-β (Aβ) is defined as a preclinical feature of Alzheimer disease, with lower levels of Aβ42 being associated with a higher risk of Alzheimer disease. To get more insight into the biological link between Alzheimer disease and cancer, we investigated plasma Aβ levels in relation to the risk of cancer.

METHODS

Between 2002 and 2005, we measured plasma Aβ40 and Aβ42 levels in 3,949 participants from the population-based Rotterdam Study. These participants were followed until the onset of cancer, all-cause dementia, death, loss to follow-up, or January 1, 2014, whichever came first. We used Cox proportional hazards models to investigate the association between plasma Aβ40 and Aβ42 levels, and the risk of cancer. Analyses were stratified by cancer site.

RESULTS

During a median (interquartile range) follow-up of 9.0 years (6.9-10.1), 560 participants were diagnosed with cancer. Higher levels of log₂ plasma Aβ40 and Aβ42 were associated with a higher risk of cancer [hazard ratio per standard deviation increase for Aβ40 = 1.12 (95% confidence interval, CI = 1.02-1.23) and Aβ42 = 1.12 (95% CI = 1.03-1.23)]. These effect estimates were most pronounced for hematologic cancers, urinary tract cancers, and cancers of unknown primary origin.

CONCLUSIONS

We found that higher levels of both plasma Aβ40 and Aβ42 were associated with a higher risk of cancer.

IMPACT

Our study suggests a potential biological link between Alzheimer disease and cancer. The pathophysiologic role of Aβ in cancer and its causality warrant further investigation.

Ascertainment of cancer in longitudinal research: The concordance between the Rotterdam Study and the Netherlands Cancer Registry

Complete and accurate registration of cancer is needed to provide reliable data on cancer incidence and to investigate aetiology. Such data can be derived from national cancer registries, but also from large population‐based cohort studies. Yet, the concordance and discordance between these two data sources remain unknown. We evaluated completeness and accuracy of cancer registration by studying the concordance between the population‐based Rotterdam Study (RS) and the Netherlands Cancer Registry (NCR) between 1989 and 2012 using the independent case ascertainment method. We compared all incident cancers in participants of the RS (aged ≥45 years) to registered cancers in the NCR in the same persons based on the date of diagnosis and the International Classification of Diseases (ICD) code. In total, 2,977 unique incident cancers among 2,685 persons were registered. Two hundred eighty‐eight cancers (9.7%) were coded by the RS that were not present in the NCR. These were mostly nonpathology‐confirmed lung and haematological cancers. Furthermore, 116 cancers were coded by the NCR, but not by the RS (3.9%), of which 20.7% were breast cancers. Regarding pathology‐confirmed cancer diagnoses, completeness was >95% in both registries. Eighty per cent of the cancers registered in both registries were coded with the same date of diagnosis and ICD code. Of the remaining cancers, 344 (14.5%) were misclassified with regard to date of diagnosis and 72 (3.0%) with regard to ICD code. Our findings indicate that multiple sources on cancer are complementary and should be combined to ensure reliable data on cancer incidence.

What's new?

While national cancer registries and population‐based cohort studies are the primary sources of data on cancer risk and incidence, the degree to which these data sets are concordant remains unknown. In this investigation, the authors evaluated concordance between the population‐based Rotterdam Study and the Netherlands Cancer Registry. The two data sets were highly concordant for pathology‐confirmed cancers and cancer site. Non‐pathology‐confirmed cancers, however, were under‐registered in the Netherlands Cancer Registry, potentially resulting in underestimation of cancer incidence. The findings highlight the important role that different sources of cancer diagnosis registration serve in providing reliable estimates of cancer incidence.

Asthma and its comorbidities in middle-aged and older adults; the Rotterdam Study

BACKGROUND

Little is known on the prevalence and characteristics of asthma in middle-aged and older adults, since previous studies mainly focused on children and young adults. Therefore, the aim was to investigate the prevalence of physician-diagnosed asthma and its comorbidities, in a population-based cohort of adults 45 years of age and over.

METHODS

We identified participants with physician-diagnosed asthma in the Rotterdam Study; a prospective population-based cohort in the Netherlands. Pulmonary function measurements and comorbidities of the asthma cases were assessed at baseline and compared to those of the general population.

RESULTS

Out of 14,621 participants (mean age 65.5 years; 59% women), 524 subjects (31.5%males) had physician-diagnosed asthma at study entry, implicating an asthma prevalence of 3.6% [95% Confidence Interval (CI) 3.3%-3.9%] (2.8% in males and 4.2% in females). Asthmatic subjects had a significantly higher prevalence of obesity and depressive symptoms (Odds Ratio [OR]: 2,02 [95% CI 1,66-2,47] and [OR]: 2,01 [95% CI 1,52-2,66] respectively). Longer duration of asthma and current smoking were associated with lower lung function in asthmatic subjects.

CONCLUSION

Four percent of middle-aged and older adults have physician-diagnosed asthma. These adult asthmatics suffer more frequently from obesity and depression than subjects without obstructive lung disease.

Measures of subclinical cardiac dysfunction and increased filling pressures associate with pulmonary arterial pressure in the general population: results from the population-based Rotterdam Study

Pulmonary hypertension is associated with increased mortality and morbidity in the elderly population. Heart failure is a common cause of pulmonary hypertension. Yet, the relation between left heart parameters reflective of subclinical cardiac dysfunction and increased filling pressures, and pulmonary arterial pressures in the elderly population remains elusive. Within the population-based Rotterdam Study, 2592 unselected participants with a mean age of 72.6 years (61.4% women) had complete echocardiography data available. We studied the cross-sectional associations of left heart structure and systolic and diastolic function with echocardiographically measured pulmonary artery systolic pressure. Mean pulmonary artery systolic pressure was 25.4 mmHg. After multivariable-adjustment measures of both structure and function were independently associated with pulmonary artery systolic pressure: E/A ratio [0.63 mmHg (95% CI 0.35–0.91) per 1-SD increase], left atrial diameter [0.79 mmHg (0.50–1.09) per 1-SD increase], E/E′ ratio [1.27 mmHg (0.92–1.61) per 1-SD increase], left ventricular volume [0.62 mmHg (0.25–0.98) per 1-SD increase], fractional shortening [0.45 mmHg (0.17–0.74) per 1-SD increase], aortic root diameter [− 0.43 mmHg (− 0.72 to − 0.14) per 1-SD increase], mitral valve deceleration time [− 0.31 mmHg (− 0.57 to − 0.05) per 1-SD increase], and E′ [1.04 mmHg (0.66–1.42) per 1-SD increase]. Results did not materially differ when restricting the analyses to participants free of symptoms of shortness of breath. Structural and functional echocardiographic parameters of subclinical cardiac dysfunction and increased filling pressures are associated with pulmonary arterial pressures in the unselected general ageing population.

The risk of bleeding complications in patients with cytochrome P450 CYP2C9*2 or CYP2C9*3 alleles on acenocoumarol or phenprocoumon

The principal enzyme involved in coumarin metabolism is CYP2C9. Allelic variants of CYP2C9, CYP2C9*2 and CYP2C9*3, code for enzymes with reduced activity. Despite increasing evidence that patients with these genetic variants require lower maintenance doses of anticoagulant therapy, there is lack of agreement among studies on the risk of bleeding and CYP2C9 polymorphisms. It was, therefore, our objective to study the effect of the CYP2C9 polymorphisms on bleeding complications during initiation and maintenance phases of coumarin anticoagulant therapy. The design of the study was a population-based cohort in a sample of the Rotterdam Study, a study in 7,983 subjects. All patients who started treatment with acenocoumarol or phenprocoumon in the study period from January 1, 1991 through December 31, 1998 and for whom INR data were available were included. Patients were followed until a bleeding complication, the end of their treatment, death or end of the study period. Proportional hazards regression analysis was used to estimate the risk of a bleeding complication in relation to CYP2C9 genotype after adjustment for several potentially confounding factors such as age, gender, target INR level, INR, time between INR measurements, and aspirin use. The effect of variant genotype on bleeding risk was separately examined during the initiation phase of 90 days after starting therapy with coumarins. The 996 patients with analysable data had a mean follow-up time of 481 days (1.3 years); 311 (31.2%) had at least 1 variant CYP2C9 allele and 685 (68.8%) had the wild type genotype. For patients with the wild type genotype, the rate of minor bleeding, major bleeding and fatal bleeding was 15.9, 3.4 and 0.2 per 100 treatmentyears, respectively. For patients with a variant genotype, the rate of minor, major and fatal bleeding was 14.6, 5.4 and 0.5 per 100 treatment-years. Patients with a variant genotype on acenocoumarol had a significantly increased risk for a major bleeding event (HR 1.83, 95% CI: 1.01-3.32). During the initiation phase of therapy we found no effect of variant genotype on bleeding risk. In this study among outpatients of an anticoagulation clinic using acenocoumarol or phenprocoumon, having a variant allele of CYP2C9 was associated with an increased risk of major bleeding events in patients on acenocoumarol, but not in patients on phenprocoumon. Although one might consider the assessment of the CYP2C9 genotype of a patient for dose adjustment before starting treatment with acenocoumarol, a prospective randomised trial should demonstrate whether this reduces the increased risk of major bleeding events.

Trends in service time of pacemakers in the Netherlands: a long-term nationwide follow-up study

AIMS

After decades of experience and strongly improved technology, service time of pacemaker generators is expected to increase. To test this hypothesis, we conducted a retrospective review of a large cohort of patients with a pacemaker.

METHODS

We reviewed data collected between 1984 and 2006 in the first national Dutch pacemaker registry. This registry covered 96% of all generators implanted. We analysed the time of and reason for explantation of pacemaker generators. A 7-year follow-up interval after first implantation and following replacements was used to analyse changes over time.

RESULTS

During 22 years of data collection, nearly 97,000 first pacemaker generators were implanted. A total of 27,937 (22.4%) generators were explanted within a mean of 6.3 (standard deviation 3.3) years. Reasons for approximately 60% of these explantations were 'end of life' of the pacemaker generator or elective system change. Complications or failures such as infections and recalls accounted for approximately 20% of the explantations. For the remaining 20%, the reasons for explantation had not been registered.

CONCLUSION

Despite progress in technology, a substantial proportion of pacemaker generators is explanted before its expected service time, with one in five generators being replaced due to technical failures, infections or other complications. Furthermore, the time interval between pacemaker implantation and explantation due to normal 'end of life' (battery EOL) decreased. Infections continue to rank highly as a cause for pacing system replacement, despite all current preventive measures.

The cholesteryl ester transfer protein I405V polymorphism is associated with increased high-density lipoprotein levels and decreased risk of myocardial infarction: the Rotterdam Study

BACKGROUND AND DESIGN

The effect of the cholesteryl ester transfer protein (CETP) I405V polymorphism on lipid levels, atherosclerosis and myocardial infarction (MI) was examined in 6421 participants from the Rotterdam Study.

METHODS

Quantitative outcomes were studied with linear models; Cox models were used to assess MI risk.

RESULTS

High-density lipoprotein cholesterol (HDL) increased by 0.06 [95% confidence interval (CI): 0.03, 0.09] mmol/l in VV carriers. The V allele was further associated with decreased MI risk in men [hazard ratio (95% confidence interval)=0.57 (0.45, 0.73), VV versus II] (Ptrend=0.02).

CONCLUSION

This study provides additional evidence for the association of CETP with HDL levels and suggests that CETP is an atherogenic protein increasing the risk of MI.

[Risk factors for adverse effects of drugs: more research is necessary]

When drugs are registered, relatively little is known about their adverse effects as clinical trials generally include only small numbers of patients and are of limited duration. New European legislation and the monitoring of adverse events are intended to enable the timely recognition of adverse effects of newly-registered drugs. However, many adverse effects of commonly-used older drugs are already well-known. Therefore, in order to improve the quality of health care, research should also be focused on the risk factors associated with developing such adverse effects.

Not-in-trial simulation I: Bridging cardiovascular risk from clinical trials to real-life conditions

AIMS

The assessment of heart rate-corrected QT (QTc) interval prolongation relies on the evidence of drug effects in healthy subjects. This study demonstrates the relevance of pharmacokinetic-pharmacodynamic (PKPD) relationships to characterize drug-induced QTc interval prolongation and explore the discrepancies between clinical trials and real-life conditions.

METHODS

d,l-Sotalol data from healthy subjects and from the Rotterdam Study cohort were used to assess treatment response in a phase I setting and in a real-life conditions, respectively. Using modelling and simulation, drug effects at therapeutic doses were predicted in both populations.

RESULTS

Inclusion criteria were shown to restrict the representativeness of the trial population in comparison to real-life conditions. A significant part of the typical patient population was excluded from trials due to weight and baseline QTc interval criteria. Relative risk was significantly different between sotalol users with and without heart failure, hypertension, diabetes and myocardial infarction (P < 0.01). Although drug effects do cause an increase in the relative risk of QTc interval prolongation, the presence of diabetes represented an increase from 4.0 [95% confidence interval (CI) 2.7-5.8] to 6.5 (95% CI 1.6-27.1), whilst for myocardial infarction it increased from 3.4 (95% CI 2.3-5.13) to 15.5 (95% CI 4.9-49.3).

CONCLUSIONS

Our findings show that drug effects on QTc interval do not explain the observed QTc values in the population. The prevalence of high QTc values in the real-life population can be assigned to co-morbidities and concomitant medications. These findings substantiate the need to account for these factors when evaluating the cardiovascular risk of medicinal products.

Bone mineral density and chronic lung disease mortality: the rotterdam study

CONTEXT

Low bone mineral density (BMD) has been associated with increased all-cause mortality. Cause-specific mortality studies have been controversial.

OBJECTIVE

The aim of the study was to investigate associations between BMD and all-cause mortality and in-depth cause-specific mortality.

DESIGN AND SETTING

We studied two cohorts from the prospective Rotterdam Study (RS), initiated in 1990 (RS-I) and 2000 (RS-II) with average follow-up of 17.1 (RS-I) and 10.2 (RS-II) years until January 2011. Baseline femoral neck BMD was analyzed in SD values. Deaths were classified according to International Classification of Diseases into seven groups: cardiovascular diseases, cancer, infections, external, dementia, chronic lung diseases, and other causes. Gender-stratified Cox and competing-risks models were adjusted for age, body mass index, and smoking.

PARTICIPANTS

The study included 5779 subjects from RS-I and 2055 from RS-II.

MAIN OUTCOME MEASUREMENTS

We measured all-cause and cause-specific mortality.

RESULTS

A significant inverse association between BMD and all-cause mortality was found in males [expressed as hazard ratio (95% confidence interval)]: RS-I, 1.07 (1.01-1.13), P = .020; RS-II, 1.31 (1.12-1.55), P = .001); but it was not found in females: RS-I, 1.05 (0.99-1.11), P = .098; RS-II, 0.91 (0.74-1.12), P = .362. An inverse association with chronic lung disease mortality was found in males [RS-I, 1.75 (1.34-2.29), P < .001; RS-II, 2.15 (1.05-4.42), P = .037] and in RS-I in females [1.72 (1.16-2.57); P = .008], persisting after multiple adjustments and excluding prevalent chronic obstructive pulmonary disease. A positive association between BMD and cancer mortality was detected in females in RS-I [0.89 (0.80-0.99); P = .043]. No association was found with cardiovascular mortality.

CONCLUSIONS

BMD is inversely associated with mortality. The strong association of BMD with chronic lung disease mortality is a novel finding that needs further analysis to clarify underlying mechanisms.

The Rotterdam Study: 2014 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

A genome-wide association study for venous thromboembolism: the extended cohorts for heart and aging research in genomic epidemiology (CHARGE) consortium

Venous thromboembolism (VTE) is a common, heritable disease resulting in high rates of hospitalization and mortality. Yet few associations between VTE and genetic variants, all in the coagulation pathway, have been established. To identify additional genetic determinants of VTE, we conducted a two-stage genome-wide association study (GWAS) among individuals of European ancestry in the extended cohorts for heart and aging research in genomic epidemiology (CHARGE) VTE consortium. The discovery GWAS comprised 1,618 incident VTE cases out of 44,499 participants from six community-based studies. Genotypes for genome-wide single-nucleotide polymorphisms (SNPs) were imputed to approximately 2.5 million SNPs in HapMap and association with VTE assessed using study-design appropriate regression methods. Meta-analysis of these results identified two known loci, in F5 and ABO. Top 1,047 tag SNPs (P ≤ 0.0016) from the discovery GWAS were tested for association in an additional 3,231 cases and 3,536 controls from three case-control studies. In the combined data from these two stages, additional genome-wide significant associations were observed on 4q35 at F11 (top SNP rs4253399, intronic to F11) and on 4q28 at FGG (rs6536024, 9.7 kb from FGG; P < 5.0 × 10(-13) for both). The associations at the FGG locus were not completely explained by previously reported variants. Loci at or near SUSD1 and OTUD7A showed borderline yet novel associations (P < 5.0 × 10(-6) ) and constitute new candidate genes. In conclusion, this large GWAS replicated key genetic associations in F5 and ABO, and confirmed the importance of F11 and FGG loci for VTE. Future studies are warranted to better characterize the associations with F11 and FGG and to replicate the new candidate associations.

Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.

Exposure to phototoxic NSAIDs and quinolones is associated with an increased risk of melanoma

PURPOSE

Ultraviolet radiation exposure is the most important exogenous risk factor for cutaneous malignancies. It is possible that phototoxic drugs promote the development of cutaneous melanoma (CM) by intensifying the effect of ultraviolet light on the skin. We investigated the association between the use of common systemic phototoxic drugs and development of CM.

METHODS

This study was a case-control study in a Dutch population-based cohort. The drug dispensing data was obtained from PHARMO, a Dutch drug dispensing and hospital admissions registry, and linked to PALGA, the nationwide pathology network of the Netherlands. The cases were patients diagnosed with pathologically confirmed primary CM between 1991 and 2004. Controls were sampled from the PHARMO population. Exposure to systemic phototoxic drugs was measured and included antimicrobial agents, diuretics, antipsychotic drugs, antidiabetic drugs, cardiac drugs, antimalarials and nonsteroidal anti-inflammatory drugs (NSAIDs). A multivariate conditional logistic regression analysis was performed to study the association between exposure to phototoxic drugs and CM.

RESULTS

The study population included 1,318 cases and 6,786 controls. Any phototoxic drug during the study period was dispensed for 46 % of the cases and 43 % of the controls (p = 0.012). The use of quinolones [odds ratio (OR) 1.33, 95 % confidence interval (CI) 1.01-1.76] and propionic acid derivative NSAIDs (OR 1.33, 95 % CI 1.14-1.54) had a positive association with CM.

CONCLUSIONS

Our study shows that the use of phototoxic drugs is associated with an increased risk of developing CM. Even a short-term use of phototoxic quinolones and propionic acid derivative NSAIDs may increase the risk for CM. Patient education to promote sun-protective behaviour is essential to avoid immediate adverse effects and possible long-term effects of phototoxic drugs.

Prescribing of rosiglitazone and pioglitazone following safety signals: analysis of trends in dispensing patterns in the Netherlands from 1998 to 2008

BACKGROUND

Relevant safety signals in the EU are regularly communicated in so-called 'Direct Healthcare Professional Communications' (DHPCs) or European Medicines Agency (EMA) press releases. Trends of a decrease in the use of rosiglitazone following regulatory safety warnings have been described in the US. In the EU, however, relatively little is known about dispensing patterns following DHPCs or other safety signals such as EMA press releases.

OBJECTIVE

The objective of this study was to analyse trends in dispensing patterns of rosiglitazone and pioglitazone following DHPCs and EMA press releases in the EU member state, the Netherlands.

METHODS

Data for this study were obtained from the PHARMO Record Linking System, which includes drug dispensing records from community pharmacies of approximately 2.5 million individuals in the Netherlands. Over the period 1998-2008 an auto-regressive, integrated, moving average model (ARIMA) was fitted. The DHPC letters or EMA press releases were used as determinants. Adjustments were made for publication of certain literature. Stratification was performed for dispensings prescribed by general practitioners (GPs) and those prescribed by specialists.

RESULTS

For rosiglitazone, four EMA press releases and two DHPCs were issued; for pioglitazone, one DHPC was issued. The number of rosiglitazone dispensings prescribed by GPs decreased significantly after publication of DHPCs and EMA press releases concerning the risk of macular oedema and risk of fractures (both p-values 0.001). The number of rosiglitazone dispensings decreased statistically significantly after publication of EMA press releases 2 and 3 concerning cardiovascular risks but not for EMA press release 4. Adjustment for certain publications in the literature reduced the effect of communicated safety issues on the proportion of dispensings.

CONCLUSIONS

Although it is difficult to disentangle the effect of DHPCs and EMA press releases from the effect of reports published in the literature, our results suggest that prescribers may react to such safety communications.

Meta-analysis identifies six new susceptibility loci for atrial fibrillation

Atrial fibrillation is a highly prevalent arrhythmia and a major risk factor for stroke, heart failure and death. We conducted a genome-wide association study (GWAS) in individuals of European ancestry, including 6,707 with and 52,426 without atrial fibrillation. Six new atrial fibrillation susceptibility loci were identified and replicated in an additional sample of individuals of European ancestry, including 5,381 subjects with and 10,030 subjects without atrial fibrillation (P < 5 × 10(-8)). Four of the loci identified in Europeans were further replicated in silico in a GWAS of Japanese individuals, including 843 individuals with and 3,350 individuals without atrial fibrillation. The identified loci implicate candidate genes that encode transcription factors related to cardiopulmonary development, cardiac-expressed ion channels and cell signaling molecules.

Concomitant use of contraceptives and potentially teratogenic medicinal products--results from a study using pharmacy dispensing data in the Netherlands

The objective of this study was to analyze to what extent potentially teratogenic medicinal products are dispensed concomitantly with contraceptives. Data on dispensed medicinal products in this population-based study were obtained from the Dutch Foundation for Pharmaceutical Statistics. For over 178 potentially teratogenic medicinal products, concomitant use of contraceptives was assessed. The proportion of potentially teratogenic medicinal products dispensed concomitantly with a contraceptive varied significantly from 40.9% (95% CI 40.7-41.2) in 2005 to 43.4% in 2009 (95% CI 44.2-43.7). Significant differences existed as well between age categories with the lowest proportions of concomitant use of contraceptives for any potentially teratogenic drug in women aged 36 through 45 years (35.0%, 95% CI 34.9-35.1) in comparison to those aged 26 through 35 years (47.1%, 95% CI 46.9-47.3) and 15 through 25 years (53.6%, 95% CI 53.4-53.8). Although our data retrieval did not cover the use of nonpharmacological forms of contraception such as condoms and sterilization and as situations may occur during which the use of drugs with (low) teratogenic potential is a balanced decision, our results raise doubts about the safe use of medicinal products with teratogenic potential.

Methods of data collection and definitions of cardiac outcomes in the Rotterdam Study

The prevalence of cardiovascular diseases is rising. Therefore, adequate risk prediction and identification of its determinants is increasingly important. The Rotterdam Study is a prospective population-based cohort study ongoing since 1990 in the city of Rotterdam, The Netherlands. One of the main targets of the Rotterdam Study is to identify the determinants and prognosis of cardiovascular diseases. Case finding in epidemiological studies is strongly depending on various sources of follow-up and clear outcome definitions. The sources used for collection of data in the Rotterdam Study are diverse and the definitions of outcomes in the Rotterdam Study have changed due to the introduction of novel diagnostics and therapeutic interventions. This article gives the methods for data collection and the up-to-date definitions of the cardiac outcomes based on international guidelines, including the recently adopted cardiovascular disease mortality definitions. In all, detailed description of cardiac outcome definitions enhances the possibility to make comparisons with other studies in the field of cardiovascular research and may increase the strength of collaborations.

Lower risk of cancer in patients on metformin in comparison with those on sulfonylurea derivatives: results from a large population-based follow-up study

OBJECTIVE

Numerous studies have suggested a decreased risk of cancer in patients with diabetes on metformin. Because different comparison groups were used, the effect magnitude is difficult to estimate. Therefore, the objective of this study was to further analyze whether, and to what extent, use of metformin is associated with a decreased risk of cancer in a cohort of incident users of metformin compared with users of sulfonylurea derivatives.

RESEARCH DESIGN AND METHODS

Data for this study were obtained from dispensing records from community pharmacies individually linked to hospital discharge records from 2.5 million individuals in the Netherlands. The association between the risk of cancer in those using metformin compared with those using sulfonylurea derivatives was analyzed using Cox proportional hazard models with cumulative duration of drug use as a time-varying determinant.

RESULTS

Use of metformin was associated with a lower risk of cancer in general (hazard ratio 0.90 [95% CI 0.88-0.91]) compared with use of sulfonylurea derivatives. When specific cancers were used as end points, similar estimates were found. Dosage-response relations were identified for users of metformin but not for users of sulfonylurea derivatives.

CONCLUSIONS

In our study, cumulative exposure to metformin was associated with a lower risk of specific cancers and cancer in general, compared with cumulative exposure to sulfonylurea derivatives. However, whether this should indeed be seen as a decreased risk of cancer for the use of metformin or as an increased risk of cancer for the use sulfonylurea derivatives remains to be elucidated.

CYP2C19*2 polymorphism is associated with increased survival in breast cancer patients using tamoxifen

AIMS

Variant alleles of the CYP2C19 gene were recently associated with survival in breast cancer patients on tamoxifen therapy. CYP2C19 is one of the enzymes involved in the metabolism of tamoxifen into active metabolites. We investigated the hypothesis that CYP2C19*2 and *3 variants, known for their lack of enzyme activity, are associated with an increased breast cancer mortality rate in patients using tamoxifen.

MATERIALS & METHODS

In the prospective population based Rotterdam study, the association between CYP2C19*2 carriers and breast cancer mortality was studied among 80 incident users of tamoxifen. Survival was analyzed with life tables and Cox regression analysis, with drug exposure as a time-dependent variable. Adjustments were made for calendar time, average tamoxifen dose, age, the indication for tamoxifen, CYP2D6 genotype and concomitant use of CYP2C19 inhibitors or inducers.

RESULTS

In patients on tamoxifen, CYP2C19*2 carriers were associated with a significantly longer breast cancer survival rate than patients with the wild-type (hazard ratio 0.26, 95%CI: 0.08-0.87).

CONCLUSION

This study suggests that CYP2C19 genotype may possibly be a predictive factor for survival in breast cancer patients using tamoxifen.

The Rotterdam Study: 2012 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Mild hyponatremia as a risk factor for fractures: the Rotterdam Study

Recent studies suggest that mild hyponatremia is associated with fractures, but prospective studies are lacking. We studied whether hyponatremia is associated with fractures, falls, and/or bone mineral density (BMD). A total of 5208 elderly subjects with serum sodium assessed at baseline were included from the prospective population-based Rotterdam Study. The following data were analyzed: BMD, vertebral fractures (mean follow-up 6.4 years), nonvertebral fractures (7.4 years), recent falls, comorbidity, medication, and mortality. Hyponatremia was detected in 399 subjects (7.7%, 133.4 ± 2.0 mmol/L). Subjects with hyponatremia were older (73.5 ± 10.3 years versus 70.0 ± 9.0 years, p < .001), had more recent falls (23.8% versus 16.4%, p < .01), higher type 2 diabetes mellitus prevalence (22.2% versus 10.3%, p < .001), and more often used diuretics (31.1% versus 15.0%, p < .001). Hyponatremia was not associated with lower BMD but was associated with increased risk of incident nonvertebral fractures [hazard ratio (HR) =1.39, 95% confidence interval (CI) 1.11-1.73, p = .004] after adjustment for age, sex, and body mass index. Further adjustments for disability index, use of diuretics, use of psycholeptics, recent falls, and diabetes did not modify results. In the fully adjusted model, subjects with hyponatremia also had increased risk of vertebral fractures at baseline [odds ratio (OR) = 1.78, 95% CI 1.04-3.06, p = .037] but not at follow-up. Finally, all-cause mortality was higher in subjects with hyponatremia (HR = 1.21, 95% CI 1.03-1.43, p = .022). It is concluded that mild hyponatremia in the elderly is associated with an increased risk of vertebral fractures and incident nonvertebral fractures but not with BMD. Increased fracture risk in hyponatremia also was independent of recent falls, pointing toward a possible effect on bone quality.

Transient ischemic attack and incident depression

BACKGROUND AND PURPOSE

Depression after stroke is common. Like stroke, transient ischemic attack (TIA) is a manifestation of long-term atherosclerotic damage to the brain. However, the risk of depression developing after a TIA is uncertain. We studied whether TIA increases the risk of incident late-life depression.

METHODS

A cohort study of 5095 inhabitants of Rotterdam, the Netherlands, was performed between 1993 and 2005. Participants were aged 56 years or older and free of depression at baseline. TIA and depression were identified through regular standardized examinations and continuous monitoring of medical records. We estimated hazard ratios (HR) with time-varying Cox regression analyses, adjusting for sociodemographic and health-related factors.

RESULTS

During follow-up, 407 depressive syndromes occurred, of which 103 met criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM) for depressive disorders. TIA was significantly associated with the risk of incident depressive syndromes (HR, 1.68; 95% CI, 1.12-2.51) and DSM-defined depressive disorders (HR, 2.42; 95% CI, 1.26-4.67). The risk of depressive syndromes increased with the number of TIA a person had experienced (HR, 1.45; 95% CI, 1.17-1.81), as did the risk of depressive disorders (HR, 1.63; 95% CI, 1.18-2.24). In persons without a history of depression at baseline, we found an almost 3-fold increased risk of DSM-defined depressive disorders (HR, 2.91; 95% CI, 0.96-8.81).

CONCLUSIONS

TIA was independently associated with an increased risk of incident depression. Our finding suggests that symptomatic cerebrovascular disease increases the vulnerability to late-life depression.

Drug- and non-drug-associated QT interval prolongation

Sudden cardiac death is among the most common causes of cardiovascular death in developed countries. The majority of sudden cardiac deaths are caused by acute ventricular arrhythmia following repolarization disturbances. An important risk factor for repolarization disturbances is use of QT prolonging drugs, probably partly explained by gene-drug interactions. In this review, we will summarize QT interval physiology, known risk factors for QT prolongation, including drugs and the contribution of pharmacogenetics. The long QT syndrome can be congenital or acquired. The congenital long QT syndrome is caused by mutations in ion channel subunits or regulatory protein coding genes and is a rare monogenic disorder with a mendelian pattern of inheritance. Apart from that, several common genetic variants that are associated with QT interval duration have been identified. Acquired QT prolongation is more prevalent than the congenital form. Several risk factors have been identified with use of QT prolonging drugs as the most frequent cause. Most drugs that prolong the QT interval act by blocking hERG-encoded potassium channels, although some drugs mainly modify sodium channels. Both pharmacodynamic as well as pharmacokinetic mechanisms may be responsible for QT prolongation. Pharmacokinetic interactions often involve drugs that are metabolized by cytochrome P450 enzymes. Pharmacodynamic gene-drug interactions are due to genetic variants that potentiate the QT prolonging effect of drugs. QT prolongation, often due to use of QT prolonging drugs, is a major public health issue. Recently, common genetic variants associated with QT prolongation have been identified. Few pharmacogenetic studies have been performed to establish the genetic background of acquired QT prolongation but additional studies in this newly developing field are warranted.

Sex-related differences in hospital admissions attributed to adverse drug reactions in the Netherlands

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Women are more at risk for developing adverse drug reactions (ADRs) due to differences in pharmacokinetics, pharmacodynamics and drug use. ADRs regularly lead to hospital admissions.

WHAT THIS STUDY ADDS

There are differences between the sexes in hospital admissions attributed to ADRs. The risk of being hospitalized with an ADR varies between the sexes in the type of reaction and the causative drug.

AIM

Adverse drug reactions (ADRs) are a major burden in health care, regularly leading to hospital admission, morbidity or death. Women tend to have a higher risk of adverse drug reactions with a 1.5 to 1.7-fold greater risk than men. Our primary aim was to study differences in ADR-related hospitalizations between the sexes.

METHODS

We conducted a nationwide study of all ADR-related hospitalizations in the period between 2000 and 2005 in the Netherlands, which were selected from all 9,287,162 hospital admissions in this period. ADR-drug group combinations with at least 50 admissions in one of the sexes were selected. Relative risks and confidence intervals were calculated with respect to total admissions and total prescriptions with men as reference.

RESULTS

In total, 0.41% of the 4,236,368 admissions in men (95% CI 0.40, 0.42%) and 0.47% of the 5,050,794 admissions in women (95% CI 0.46, 0.48%) were attributed to an ADR by medical specialists (57% of all ADR-related admissions were in women). Differences between the sexes in risk for ADR-related hospitalization were found for antineoplastic and immunosuppressive drugs, antirheumatics, anticoagulants and salicylates, cardiovascular and neurological drugs, steroids and antibiotics. In certain drug categories, risks for hospitalization changed after taking into account total drug prescriptions.

CONCLUSION

In all different drug classes, significant differences exist between the sexes in ADR-related hospital admissions. Cardiovascular drugs account for the most pronounced differences between men and women. More research is needed to explain the clear sex differences in ADR-related hospital admissions.

Pharmacogenetic interactions between ABCB1 and SLCO1B1 tagging SNPs and the effectiveness of statins in the prevention of myocardial infarction

AIMS

Genetic variability within the SLCO1B1 and ABCB1 transporter genes has been associated with modification of statin effectiveness in cholesterol management.

MATERIALS & METHODS

We conducted a case-control study using a population-based registry of pharmacy records linked to the hospital discharge records. Within a hypercholesterolemic cohort, we included 668 myocardial infarction cases and 1217 controls.

RESULTS

We tested 24 tagging SNPs and found two SNPs within ABCB1 (rs3789244, p = 0.01; rs1922242, p = 0.01) to interact with statin treatment. In addition, we found a nonsignificant haplotype-treatment interaction (p = 0.054). The odds ratio for subjects homozygous for SLCO1B1*1A was 0.49 (95% CI: 0.34-0.71) compared with 0.31 (95% CI: 0.24-0.41) for heterozygous or noncarriers of the *1A allele.

CONCLUSION

This is the first study to demonstrate that common genetic variability within the SLCO1B1 and ABCB1 genes is associated with the modification of the effectiveness of statins in the prevention of the clinical outcome, myocardial infarction.

Cytochrome P450 3A gene variation, steroid hormone serum levels and prostate cancer--The Rotterdam Study

PURPOSE

To study if polymorphisms in genes encoding for CYP3A enzymes, that play a role in steroid hormone metabolism, affect steroid hormone serum levels and prostate cancer incidence or mortality.

METHODS

3048 male participants of The Rotterdam Study were included. Prostate cancer cases and non-cases were studied for differences in baseline hormone levels with Student's t-test. General linear models were performed on different random subsets of hormone levels to study associations with genotype. Cox' proportional hazard models were used to study prostate cancer incidence and mortality among genotypes.

RESULTS

Both DHEAS sulphate as free-testosterone were significantly increased at baseline in males who developed a prostate cancer within the study period. CYP3A4 G-allele carriage was associated with lower levels of estrone sulphate (p=0.005) and higher levels of estradiol (p=0.04) compared to non-carriers. CYP3A5 A-allele carriage was associated with increased levels of estrone sulphate (p=0.02). CYP3A7 G-allele carriage was associated with the highest number of significant differences in steroid hormone levels. Carriers of the allele resulting in continued enzyme expression during adulthood had decreased levels of dehydroepiandrosterone (DHEA) sulphate (p=0.05), androstenedione (p=0.006), estrone (p=0.0001) and estrone sulphate (p=0.003) compared to mean levels of these hormones in homozygous wild type carriers. CYP3A43 genotype was not associated with any of the studied hormone levels. However, carriers of the CYP3A43 G-allele showed a significant 5-fold increase in mortality among early onset diagnosed prostate cancers.

CONCLUSION

Increased levels of free testosterone and DHEA sulphate were associated with prostate cancer incidence along the study period. Primarily the amount of CYP3A7 expression seemed to affect steroid hormone levels. Nevertheless, testosterone, a precursor of the prostate growth and differentiation stimulating dehydrotestosterone, was not influenced by CYP3A genotype. In line with this, no significant associations were observed for CYP3A genotypes and prostate cancer incidence.

Effect of short-term NSAID use on echocardiographic parameters in elderly people: a population-based cohort study

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with an increased risk of heart failure. NSAIDs inhibit the synthesis of renal prostaglandin, which results in a higher total blood volume, cardiac output and preload. The association between recent start of NSAIDs in elderly people and echocardiographic parameters was investigated.

METHODS

In the Rotterdam Study, a population-based cohort study, the effect of NSAIDs on left ventricular end-systolic dimension, left ventricular end-diastolic dimension, fractional shortening and left ventricular systolic function was studied in all participants for whom an echocardiogram was available (n=5307). NSAID use was categorised as current NSAID use on the date of echocardiography, past use and never used before echocardiography during the study period. Current use was divided into short-term NSAID use (≤ 14 days) and long-term NSAID use (> 14 days). Associations between drug exposure and echocardiographic measurements were assessed using linear and logistic regression analyses.

RESULTS

Current NSAID use for < 14 days was associated with a significantly higher left ventricular end-systolic dimension (+1.74 mm, 95% CI 0.20 to 3.28), left ventricular end-diastolic dimension (+3.69 mm, 95% CI 1.08 to 6.31) and significantly lower fractional shortening (-6.03%, 95% CI -9.81% to -2.26%) compared with non-users. Current NSAID use for > 14 days was associated with a higher left end-diastolic dimension (+1.96 mm, 95% CI 0.82 to 3.11) but there was no change in the other echocardiographic parameters.

CONCLUSION

This study is the first to investigate the association between NSAIDs and echocardiographic parameters and suggests that there is a transient effect of short-term use of NSAIDs on the left ventricular dimension and function of the heart.

Common variants in 22 loci are associated with QRS duration and cardiac ventricular conduction

QRS interval on the electrocardiogram reflects ventricular depolarization and conduction time, and is a risk factor for mortality, sudden death, and heart failure. We performed a genome-wide association meta-analysis in 40,407 European-descent individuals from 14 studies, with further genotyping in 7170 additional Europeans, and identified 22 loci associated with QRS duration (P < 5 × 10⁻⁸). These loci map in or near genes in pathways with established roles in ventricular conduction such as sodium channels, transcription factors, and calcium-handling proteins, but also point to novel biologic processes, such as kinase inhibitors and genes related to tumorigenesis. We demonstrate that SCN10A, a gene at our most significant locus, is expressed in the mouse ventricular conduction system, and treatment with a selective SCN10A blocker prolongs QRS duration. These findings extend our current knowledge of ventricular depolarization and conduction.

Association between calcium channel blockers and gingival hyperplasia

AIM

To study the effect of the dose and type of calcium channel blockers (CCBs) on the risk of gingival hyperplasia and to quantify this association.

METHODS

The study was conducted within the Integrated Primary Care Information Project in The Netherlands. A nested case-control study was designed within a cohort of all patients who were new users of either CCBs or drugs interacting with the renin-angiotensin system (RAS). Cases were all individuals with a validated diagnosis of gingival hyperplasia. Controls were matched on age, gender and index date.

RESULTS

Within the study population, 103 cases of gingival hyperplasia were identified and matched to 7677 controls. The risk of gingival hyperplasia was higher in current users of CCBs [adjusted odds ratio (OR(adj)) 2.2, 95% confidence intervals (95% CI): 1.4-3.4], especially in dihydropyridines (OR(adj) 2.1, 95% CI: 1.3-3.5) and benzothiazepine derivatives (OR(adj) 2.9, 95% CI: 1.3-6.5) than in RAS drug users. The risk increased in patients using more than the recommended daily dose (OR(adj) 3.0, 95% CI: 1.6-5.5) and when the duration of current use was <1 month (OR(adj) 5.2, 95% CI: 2.1-12.6).

CONCLUSION

This study shows that the risk of gingival hyperplasia is twofold higher in current users of CCBs than in users of RAS drugs. The association was dose dependent and the highest for dihydropyridines or benzothiazepine derivates.

Vitamin D-binding protein polymorphisms are not associated with development of (multiple) basal cell carcinomas

Vitamin D-binding protein (VDBP) single nucleotide polymorphisms (SNP) may affect skin carcinogenesis. The objective was to test the association between two functional VDBP SNPs and the susceptibility to (multiple) basal cell carcinomas (BCCs). Of the 7983 participants, 5790 (72.5%) and 5823 (72.9%) participants were genotyped for rs7041 and rs4588, respectively, and three haplotypes (Gc1s, Gc2 and Gc1f) were analysed. Two hundred and thirty-three persons developed a BCC of whom 122 (52.4%) developed multiple BCCs during a mean follow-up of 11.6 years. The VDBP genotype was not associated with (multiple) BCC development using Cox proportional hazards and Andersen-Gill analyses, respectively. Stratifying age groups demonstrated that in the youngest age-group, the A/T variant of rs7041 was associated with BCC development [adjusted hazard ratio (HR) = 1.88 (95%CI 1.10-3.20)], while homozygote Gc1s carriers had a significantly lower BCC risk [adjusted HR = 0.53 (95%CI 0.31-0.91)]. In conclusion, the VDBP polymorphisms were not associated with susceptibility to (multiple) BCCs, but age-gene interactions were observed.

OCT1 polymorphism is associated with response and survival time in anti-Parkinsonian drug users

Substrates for the Organic Cation Transporter 1, encoded by the SLC22A1 gene, are metformin, amantadine, pramipexole, and, possibly, levodopa. Recently, we identified that the rs622342 A > C polymorphism is associated with the HbA1c lowering effect in metformin users. In the Rotterdam Study, we associated this polymorphism with higher prescribed doses of all anti-Parkinsonian drugs. Between the first and fifth prescriptions for levodopa, for each minor rs622342 C allele, the prescribed doses were 0.34 defined daily dose higher (95% CI 0.064, 0.62; p=0.017). The mortality ratio after start of levodopa therapy was 1.47 times higher (95% CI 1.01, 2.13; p=0.045).

Genome-wide association analysis identifies multiple loci related to resting heart rate

Higher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel factors that influence pathologic heart rate states, modulate heart rate through cardiac structure and function or by improving our understanding of the physiology of heart rate regulation. To identify common genetic variants associated with heart rate, we performed a meta-analysis of 15 genome-wide association studies (GWAS), including 38,991 subjects of European ancestry, estimating the association between age-, sex- and body mass-adjusted RR interval (inverse heart rate) and approximately 2.5 million markers. Results with P < 5 × 10(-8) were considered genome-wide significant. We constructed regression models with multiple markers to assess whether results at less stringent thresholds were likely to be truly associated with RR interval. We identified six novel associations with resting heart rate at six loci: 6q22 near GJA1; 14q12 near MYH7; 12p12 near SOX5, c12orf67, BCAT1, LRMP and CASC1; 6q22 near SLC35F1, PLN and c6orf204; 7q22 near SLC12A9 and UfSp1; and 11q12 near FADS1. Associations at 6q22 400 kb away from GJA1, at 14q12 MYH6 and at 1q32 near CD34 identified in previously published GWAS were confirmed. In aggregate, these variants explain approximately 0.7% of RR interval variance. A multivariant regression model including 20 variants with P < 10(-5) increased the explained variance to 1.6%, suggesting that some loci falling short of genome-wide significance are likely truly associated. Future research is warranted to elucidate underlying mechanisms that may impact clinical care.

Isotretinoin use and compliance with the Dutch Pregnancy Prevention Programme: a retrospective cohort study in females of reproductive age using pharmacy dispensing data

BACKGROUND

Isotretinoin is very effective in the treatment of severe acne. However, because of the teratogenic properties of this agent an isotretinoin Pregnancy Prevention Programme (PPP) was implemented in the Netherlands to guarantee that treatment is contraindicated in women of reproductive age unless at least one effective method of contraception is used. Furthermore, the PPP stipulates that isotretinoin treatment should be managed by physicians or specialists experienced in treatment with this drug and that only monthly prescriptions are issued.

OBJECTIVE

To assess compliance with the Dutch isotretinoin PPP in women of reproductive age during the study period of 1 January 2005 to 31 December 2008.

METHODS

Detailed information on dispensed medication and co-medication was available from the Dutch Foundation of Pharmaceutical Statistics. Four types of outcome were studied: concomitant dispensing of hormonal contraceptive with isotretinoin; the proportion of specialist prescribing of isotretinoin; prescribing of conventional acne therapy prior to isotretinoin initiation; and isotretinoin dispensing exceeding the maximum amount. The use of contraceptives in women aged between 15 and 45 years was defined as concomitant if the period of systemic contraceptive use overlapped the period of isotretinoin dispensing for at least 10 days, or if any dispensing of an intrauterine or intravaginal contraceptive was recorded since the year 2000. Dispensings were separated into those prescribed by either specialists or general practitioners (GPs). The use of antibacterials, antiandrogens or topical agents against acne was checked 4 months prior to an isotretinoin dispensing, and a possible excess of the maximum amount of isotretinoin was defined as prescriptions of more than 100 defined daily doses.

RESULTS

During the study period, data were available for 442 Dutch pharmacies encompassing 4881 women of reproductive age using isotretinoin at least once during study period. Among women of reproductive age, the use of isotretinoin increased during the study period. The proportion of isotretinoin initiation with concomitant oral hormonal or intrauterine contraceptives was low (59.3% [95% CI 57.6, 61.0]). Initiation of isotretinoin by a specialist increased the chance for concomitant contraception by 26% (95% CI 6.0, 49.0); in 78.2% (95% CI 76.8, 79.6) of women, isotretinoin was initiated by a specialist. Conventional acne therapy up to 16 months prior to isotretinoin initiation was found in 70% of the women (70.3% [95% CI 66.0, 74.6]). In 1.4% (95% CI 1.0, 1.8) of cases of treatment initiation, the amount of isotretinoin dispensed on one prescription seemed too high.

CONCLUSION

Attention should be paid to improving the implementation of the isotretinoin PPP. Despite clear guidelines and warnings in the product information, our study strongly suggests that concomitant use of isotretinoin and contraceptives is too low. Even though we will have missed non-pharmacological forms of contraception, these results raise doubts about the safe use of isotretinoin in women of reproductive age in the Netherlands. Furthermore, isotretinoin does not seem to be used in cases of severe acne only. Reserving isotretinoin prescribing to specialists may improve adherence to the PPP.

Non-cardiovascular drugs that inhibit hERG-encoded potassium channels and risk of sudden cardiac death

BACKGROUND

Virtually all QTc-prolonging drugs act by blocking the human ether a go-go-related gene (hERG)-encoded potassium channels (hERG channels), whereas not all QTc-prolonging drugs are associated with an increased risk of serious cardiac arrhythmias. This study assessed whether non-cardiovascular hERG channel blockers are associated with an increased risk of sudden cardiac death (SCD) and whether hERG-channel-inhibiting capacity is an indicator of the risk of SCD.

METHODS AND RESULTS

The risk of SCD was studied in the Integrated Primary Care Information database, a longitudinal general practice research database. A case-control study was performed, matched for age, gender and calendar time. Odds ratios were calculated with conditional logistic regression, multivariably adjusted. In addition, the hERG-channel-inhibiting capacity of the different drugs was compared, defined as the effective free therapeutic plasma concentration (ETCP(unbound)) divided by the concentration that inhibits 50% of the potassium channels (IC50), with the risk of SCD. 1424 cases of SCD and 14 443 controls were identified. Current use of hERG channel blockers was associated with an increased risk of SCD. The risk of SCD was significantly increased in users of antipsychotic drugs. Patients using hERG channel blockers with a high ETCP(unbound)/IC50 ratio (≥ 0.033) had a higher risk of SCD than patients using drugs with a low ETCP(unbound)/IC50 ratio (<0.033).

CONCLUSIONS

The current use of hERG channel blockers was associated with an increased risk of SCD in the general population. In addition, drugs with a high hERG-channel-inhibiting capacity had a higher risk of SCD than drugs with a low hERG-channel-inhibiting capacity.

Population-based studies of antithyroid drugs and sudden cardiac death

AIM

Thyroid free T4 is associated with QTc-interval prolongation, which is a risk factor for sudden cardiac death (SCD). Hyperthyroidism has been associated with SCD in case reports, but there are no population-based studies confirming this. The aim was to investigate whether use of antithyroid drugs (as a direct cause or as an indicator of poorly controlled hyperthyroidism) is associated with an increased risk of SCD.

METHODS

We studied the occurrence of SCD in a two-step procedure in two different Dutch populations. First, the prospective population-based Rotterdam Study including 7898 participants (> or =55 years old). Second, we used the Integrated Primary Care Information (IPCI) database, which is a longitudinal general practice research database to see whether we could replicate results from the first study. Drug use at the index date was assessed with prescription information from automated pharmacies (Rotterdam Study) or drug prescriptions from general practices (IPCI). We used a Cox proportional hazards model in a cohort analysis, adjusted for age, gender and use of QTc prolonging drugs (Rotterdam Study) and conditional logistic regression analysis in a case-control analysis, matched for age, gender, practice and calendar time and adjusted for arrhythmia and cerebrovascular ischaemia (IPCI).

RESULTS

In the Rotterdam Study, 375 participants developed SCD during follow-up. Current use of antithyroid drugs was associated with SCD [adjusted hazard ratio 3.9; 95% confidence interval (CI) 1.7, 8.7]. IPCI included 1424 cases with SCD and 14 443 controls. Also in IPCI, current use of antithyroid drugs was associated with SCD (adjusted odds ratio 2.9; 95% CI 1.1, 7.4).

CONCLUSIONS

Use of antithyroid drugs was associated with a threefold increased risk of SCD. Although this might be directly caused by antithyroid drug use, it might be more readily explained by underlying poorly controlled hyperthyroidism, since treated patients who developed SCD still had low thyroid-stimulating hormone levels shortly before death.

Variation in the CYP2D6 gene is associated with a lower serum sodium concentration in patients on antidepressants

AIM

To study the effect of the CYP2D6*4 polymorphism on serum sodium concentration in users of antidepressants [selective serotonin reuptake inhibitors and tricyclic antidepressants (TCAs)].

METHODS

In this population-based cohort study, all subjects in the Rotterdam Study were included who used an antidepressant at baseline and from whom a blood sample was available in which CYP2D6 genotype and serum sodium concentration could be determined (n= 76). Multivariate linear regression was used to study the association between CYP2D6*4 and serum sodium concentration.

RESULTS

CYP2D6 poor metabolizers (PMs) (*4/*4) had a significantly lower mean serum sodium concentration in comparison with CYP2D6 extensive metabolizers (EMs) (*1/*1) [difference -3.9 mmol l(-1); 95% confidence interval (CI) -0.86, -7.03; P= 0.013]. In CYP2D6*4 heterozygotes (*1/*4) serum sodium concentration was 1.7 mmol l(-1) (95% CI -3.48, 0.18) lower compared with CYP2D6 EMs, but this difference was not statistically significant (P= 0.077).

CONCLUSIONS

The serum sodium concentration in PMs was lower in users of an antidepressant, especially in TCA users. Therefore CYP2D6 PMs might be at increased risk of developing symptoms of hyponatraemia.

Influence of genetic variation in CYP3A4 and ABCB1 on dose decrease or switching during simvastatin and atorvastatin therapy

PURPOSE

Simvastatin and atorvastatin are metabolized by the CYP3A4 enzyme and transported by the ABCB1 transporter. We studied whether the polymorphism CYP3A4*1B and the polymorphisms C1236T, G2677A/T and C3435T in the ABCB1 gene were associated with a decrease of the prescribed dose or a switch to another cholesterol lowering drug during simvastatin and atorvastatin therapy. These events may indicate that statin plasma levels were too high and resulted in an adverse drug reaction or a too strong reduction in cholesterol level.

METHODS

We identified 1239 incident simvastatin and atorvastatin users in the Rotterdam Study, a population-based cohort study. Associations between the polymorphisms in the CYP3A4 and ABCB1 gene and the time to a decrease in dose or a switch to another cholesterol lowering drug were studied using Cox proportional hazards.

RESULTS

Simvastatin and atorvastatin users with the CYP3A4*1B variant G allele had a lower risk (HR 0.46; 95%CI 0.24-0.90) for these events than users with the wild-type AA genotype. No significant associations were found for the ABCB1 polymorphisms. The association with the CYP3A4*1B polymorphism was found in women (HR 0.33; 95%CI 0.12-0.89) and was non-significant in men (HR 0.69 95%CI 0.28-1.70). This association was stronger in patients with the ABCB1 3435T variant allele versus the G allele.

CONCLUSION

In simvastatin and atorvastatin users, the CYP3A4*1B G allele is associated with a lower risk of elevated statin plasma levels, particularly in women and in users with the ABCB1 3435T variant allele.

Common variants in KCNN3 are associated with lone atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia. A subset of patients with lone AF have no overt heart disease and an increased heritability of AF. We sought to identify common genetic variants underlying lone AF. Cases were from the German AF Network, Heart and Vascular Health Study, Atherosclerosis Risk in Communities Study, Cleveland Clinic, and Massachusetts General Hospital. Subjects were genotyped, HapMap SNPs imputed, and age- sex- and hypertension-adjusted analyses performed. A meta-analysis was conducted using 1,335 cases of lone AF and 12,844 referents. A novel locus on chromosome 1q21 was identified, and the most significant SNP, rs13376333, had an adjusted odds ratio of 1.56 (P=6.3×10⁻¹²). This association was replicated in two cohorts with lone AF for an overall odds ratio of 1.52 (P=1.83×10⁻²¹). Rs13376333 is intronic to KCNN3, a potassium channel involved in atrial repolarization. KCNN3 represents a novel potential therapeutic target in the treatment of AF.

Serum glucose and insulin are associated with QTc and RR intervals in nondiabetic elderly

AIMS

To study whether nondiabetic persons with impaired fasting serum glucose and hyperinsulinemia have QTc/QT interval prolongation and RR interval shortening in the electrocardiogram (ECG), and whether these were associated with an increased risk of sudden cardiac death.

METHODS

This study consisted of two analyses. First, a cross-sectional analysis was used as part of the population-based Rotterdam Study including 1050 men and 1520 women (>or=55 years) without diabetes mellitus. Participants in round 3 of the Rotterdam Study for whom an ECG and fasting serum glucose and fasting insulin measurements were available were eligible for the study. Participants using digoxin or QTc-prolonging drugs and participants with left ventricular hypertrophy and left and right bundle branch block were excluded. The endpoints of the study were the lengths of the QTc, QT, and RR intervals. The associations were examined by means of linear regression analysis. Secondly, in all 6020 participants of the Rotterdam Study with an ECG, the associations between the QTc, QT, and RR intervals and sudden cardiac death were examined by means of Cox regression analysis.

RESULTS

Overall, there was a significant association between impaired fasting serum glucose and the QTc interval with an increase of 2.6 ms (95% confidence interval (CI): 0.3; 5.0) in those with fasting glucose >6 mmol/l. Hyperinsulinemia was also associated with QTc prolongation (3.0 ms (0.8; 5.3)) in those with fasting insulin >or=100 pmol/l. Impaired fasting glucose (IFG) and hyperinsulinemia were significantly associated with a decrease of the RR interval (-33.7 ms (-48.8; -18.6) and -44.4 ms (-58.7; -30.0) respectively). Participants in the fourth quartile of the QTc and QT intervals had a significantly increased risk of sudden cardiac death compared to participants in the first quartile (hazard ratio (HR) 2.87 (95% CI: 2.02-4.06); HR 3.05 (1.99-4.67) respectively). Furthermore, there was a significant inverse association between the fourth quartile of the RR interval compared to the first quartile and the risk of sudden cardiac death (HR 0.49 (0.34-0.80)).

CONCLUSION

In this population-based study, we demonstrated that IFG and hyperinsulinemia are associated with a significantly increased QTc interval and with significant shortening of the RR interval, the latter probably due to an increased sympathetic activity. In addition, we demonstrated that both a prolonged QTc interval and a shortened RR interval are associated with an increased risk of sudden cardiac death.

Common genetic variation in the ABCB1 gene is associated with the cholesterol-lowering effect of simvastatin in males

AIMS

The cholesterol-lowering drug simvastatin is a substrate for P-glycoprotein (P-gp). P-gp, encoded by ABCB1, is an efflux transporter and genetic variation in ABCB1 is associated with drug levels and response. We examined the Rotterdam Study, which is a population-based cohort study of people aged 55 years and older, to see whether the C1236T, G2677T/A and C3435T polymorphisms and haplotypes in the ABCB1 gene are associated with the total cholesterol and low-density lipoprotein cholesterol-lowering effect of simvastatin.

MATERIALS & METHODS

We identified 85 incident simvastatin users, for whom a cholesterol measurement both before and after the start of simvastatin therapy was available. Associations between the ABCB1 gene variants and reductions in cholesterol levels were analyzed. In our analysis we stratified for gender, because the level of P-gp expression in the liver is higher in men than in women.

RESULTS

The three ABCB1 polymorphisms were associated with total cholesterol reduction in the whole population. In men, both the 1236/2677/3435 TTT haplotype and the CGT haplotype were associated with larger reductions in total cholesterol (TTT: -0.40 mmol/l, 95% CI: -0.63 to -0.17; CGT: -0.44 mmol/l, 95% CI: -0.77 to -0.11) and low-density lipoprotein cholesterol levels (TTT: -0.51 mmol/l, 95% CI: -0.81 to -0.22; CGT: -0.53 mmol/l, 95% CI: -0.92 to -0.15) than the reference CGC haplotype. In women, genetic variation in the ABCB1 gene was not associated with total and low-density lipoprotein cholesterol levels.

CONCLUSION

Male simvastatin users with the ABCB1 1236/2677/3435 TTT and CGT haplotype have larger reductions in total cholesterol and low-density lipoprotein cholesterol compared with the wild-type CGC haplotype. For women, no associations were found.

The association of serum testosterone levels and ventricular repolarization

It is assumed that testosterone is an important regulator of gender-related differences in ventricular repolarization. Therefore, our aim was to study whether serum levels of testosterone are associated with QTc, QT and RR interval variation. Setting: two independent population-based cohort studies. Participants: 445 male participants (≥55 years) from the Rotterdam study cohort and 1,428 male participants from the study of health in Pomerania (SHIP) with an electrocardiogram who were randomly sampled for assessment of serum testosterone at baseline, after exclusion of participants with testosterone altering drugs, QTc prolonging drugs or dig(it)oxin, left ventricular hypertrophy and left and right bundle branch block. Endpoints: length of the QTc, QT and RR intervals. Analysis: linear regression model, adjusted for the two individual studies and a pooled analysis of both studies. The pooled analysis of the Rotterdam study and SHIP showed that the QTc interval gradually decreased among the tertiles (P value for trend 0.024). The third tertile of serum testosterone was associated with a lower QTc interval compared to the first tertile [−3.4 ms (−6.5; −0.3)]. However, the third tertile of serum testosterone was not associated with a lower QT interval compared to the first tertile [−0.7 ms (−3.1; 1.8)]. The RR interval gradually increased among the tertiles (P value for trend 0.002) and the third tertile of serum testosterone showed an increased RR interval compared to the first tertile [33.5 ms (12.2; 54.8)]. In the pooled analysis of two population-based studies, serum testosterone levels were not associated with the QT interval, which could be due to a lack of power. Lower QTc intervals in men with higher serum testosterone levels could be due to the association of serum testosterone with prolongation of the RR interval.

Association between the CYP2D6*4 polymorphism and depression or anxiety in the elderly

INTRODUCTION

5-methoxytryptamine (5-MT), a precursor of serotonin, is considered to be an endogenous substrate of cytochrome P450 2D6 (CYP2D6). Homozygous carriers of the variant allele CYP2D6*4 lack CYP2D6 enzyme activity. Relative to extensive metabolizers, these poor metabolizers may have lower baseline serotonin concentrations in various brain regions, and may be more prone to depression or anxiety.

AIM

To test whether the CYP2D6*4/*4 genotype is associated with a predisposition to depression or anxiety disorders in the elderly.

MATERIALS & METHODS

We conducted a cross-sectional study within the Rotterdam Study, a population-based cohort study, among persons aged 55 years or older, who were screened for depression and anxiety disorders at two consecutive examination rounds. Logistic regression was used to analyze the association between the CYP2D6*4 polymorphism and the risk of depression or anxiety disorders.

RESULTS

The risk of major depression in CYP2D6*4/*4 was not significantly different from extensive metabolizers (OR = 0.85; 95% CI: 0.36-2.00; p = 0.72). Neither did we find an association between CYP2D6 genotype and minor depression (OR = 1.56; 95% CI: 0.69-3.52; p = 0.28). No increased risk of anxiety disorders was found (OR = 1.19; 95% CI: 0.68-2.09; p = 0.55).

CONCLUSION

Variation in the CYP2D6 gene is not related to a predisposition to depression or anxiety disorders in the elderly.

Variants in ZFHX3 are associated with atrial fibrillation in individuals of European ancestry

We conducted meta-analyses of genome-wide association studies (GWAS) for atrial fibrillation (AF) in participants from five community-based cohorts. Meta-analyses of 896 prevalent (15,768 referents) and 2,517 incident (21,337 referents) AF cases identified a novel locus for AF (ZFHX3, rs2106261, risk ratio [RR]=1.19; P=2.3×10⁻⁷), an association that was replicated in the German AF Network (odds ratio=1.44; P=1.6×10⁻¹¹). Combining the discovery and replication results, rs2106261 was significantly associated with AF (RR=1.25; P=1.8×10⁻¹⁵).