The role of plasma concentrations and drug characteristics of beta-blockers in fall risk of older persons

Beta-blocker usage is inconsistently associated with increased fall risk in the literature. However, due to age-related changes and interindividual heterogeneity in pharmacokinetics and dynamics, it is difficult to predict which older adults are more at risk for falls. Therefore, we wanted to explore whether elevated plasma concentrations of selective and nonselective beta-blockers are associated with an increased risk of falls in older beta-blocker users. To answer our research question, we analyzed samples of selective (metoprolol, n = 316) and nonselective beta-blockers (sotalol, timolol, propranolol, and carvedilol, n = 179) users from the B-PROOF cohort. The associations between the beta-blocker concentration and time to first fall were assessed using Cox proportional hazard models. Change of concentration over time in relation to fall risk was assessed with logistic regression models. Models were adjusted for potential confounders. Our results showed that above the median concentration of metoprolol was associated with an increased fall risk (HR 1.55 [1.11-2.16], p = .01). No association was found for nonselective beta-blocker concentrations. Also, changes in concentration over time were not associated with increased fall risk. To conclude, metoprolol plasma concentrations were associated with an increased risk of falls in metoprolol users while no associations were found for nonselective beta-blockers users. This might be caused by a decreased β1-selectivity in high plasma concentrations. In the future, beta-blocker concentrations could potentially help clinicians estimate fall risk in older beta-blockers users and personalize treatment.

Smoking-related dysregulation of plasma circulating microRNAs: the Rotterdam study

BACKGROUND

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression. Differential miRNA expression, which is widely shown to be associated with the pathogenesis of various diseases, can be influenced by lifestyle factors, including smoking. This study aimed to investigate the plasma miRNA signature of smoking habits, the potential effect of smoking cessation on miRNA levels, and relate the findings with lung cancer incidence.

RESULTS

A targeted RNA-sequencing approach measured plasma miRNA levels in 2686 participants from the population-based Rotterdam study cohort. The association between cigarette smoking (current versus never) and 591 well-expressed miRNAs was assessed via adjusted linear regression models, identifying 41 smoking-associated miRNAs that passed the Bonferroni-corrected threshold (P < 0.05/591 = 8.46 × 10^-5). Moreover, we found 42 miRNAs with a significant association (P < 8.46 × 10^-5) between current (reference group) and former smokers. Then, we used adjusted linear regression models to explore the effect of smoking cessation time on miRNA expression levels. The expression levels of two miRNAs were significantly different within 5 years of cessation (P < 0.05/41 = 1.22 × 10^-3) from current smokers, while for cessation time between 5 and 15 years we found 19 miRNAs to be significantly different from current smokers, and finally, 38 miRNAs were significantly different after more than 15 years of cessation time (P < 1.22 × 10^-3). These results imply the reversibility of the smoking effect on plasma levels of at least 38 out of the 41 smoking-miRNAs following smoking cessation. Next, we found 8 out of the 41 smoking-related miRNAs to be nominally associated (P < 0.05) with the incidence of lung cancer.

CONCLUSIONS

This study demonstrates smoking-related dysregulation of plasma miRNAs, which might have a potential for reversibility when comparing different smoking cessation groups. The identified miRNAs are involved in several cancer-related pathways and include 8 miRNAs associated with lung cancer incidence. Our results may lay the groundwork for further investigation of miRNAs as potential mechanism linking smoking, gene expression and cancer.

Chronic Cough-Related Differences in Brain Morphometry in Adults: A Population-Based Study

BACKGROUND

Individuals with cough hypersensitivity have increased central neural responses to tussive stimuli, which may result in maladaptive morphometric changes in the central cough processing systems.

RESEARCH QUESTION

Are the volumes of the brain regions implicated in cough hypersensitivity different in adults with chronic cough compared with adults without chronic cough?

STUDY DESIGN AND METHODS

Between 2009 and 2014, participants in the Rotterdam Study, a population-based cohort, underwent brain MRI and were interviewed for chronic cough, which was defined as daily coughing for at least 3 months. Regional brain volumes were quantified with the use of parcellation software. Based on literature review, we identified and studied seven brain regions that previously had been associated with altered functional brain activity in chronic cough. The relationship between chronic cough and regional brain volumes was investigated with the use of multivariable regression models.

RESULTS

Chronic cough was prevalent in 9.6% (No. = 349) of the 3,620 study participants (mean age, 68.5 ± 9.0 years; 54.6% women). Participants with chronic cough had significantly smaller anterior cingulate cortex volume than participants without chronic cough (mean difference, -126.16 mm³; 95% CI, -245.67 to -6.66; P = .039). Except for anterior cingulate cortex, there were no significant difference in the volume of other brain regions based on chronic cough status. The volume difference in the anterior cingulate cortex was more pronounced in the left hemisphere (mean difference, -88.11 mm³; 95% CI, -165.16 to -11.06; P = .025) and in men (mean difference, -242.58 mm³; 95% CI, -428.60 to -56.55; P = .011).

INTERPRETATION

Individuals with chronic cough have a smaller volume of the anterior cingulate cortex, which is a brain region involved in cough suppression.

CLINICAL TRIAL REGISTRATION

The Netherlands National Trial Registry (NTR; www.trialregister.nl) and the World Health Organization's International Clinical Trials Registry Platform (ICTRP; www.who.int/ictrp/network/primary/en/) under the joint catalogue number NTR6831.

Genetic analyses of the electrocardiographic QT interval and its components identify additional loci and pathways

The QT interval is an electrocardiographic measure representing the sum of ventricular depolarization and repolarization, estimated by QRS duration and JT interval, respectively. QT interval abnormalities are associated with potentially fatal ventricular arrhythmia. Using genome-wide multi-ancestry analyses (>250,000 individuals) we identify 177, 156 and 121 independent loci for QT, JT and QRS, respectively, including a male-specific X-chromosome locus. Using gene-based rare-variant methods, we identify associations with Mendelian disease genes. Enrichments are observed in established pathways for QT and JT, and previously unreported genes indicated in insulin-receptor signalling and cardiac energy metabolism. In contrast for QRS, connective tissue components and processes for cell growth and extracellular matrix interactions are significantly enriched. We demonstrate polygenic risk score associations with atrial fibrillation, conduction disease and sudden cardiac death. Prioritization of druggable genes highlight potential therapeutic targets for arrhythmia. Together, these results substantially advance our understanding of the genetic architecture of ventricular depolarization and repolarization.

General practice database on mortality in adults on methylphenidate: cohort study

OBJECTIVES

Methylphenidate is a 'prescription only' drug against attention disorders which is increasingly used by adults. We investigated whether methylphenidate in adults was associated with an increased risk of psychiatric events such as depression, and suicide attempt and overall mortality.

DESIGN

A population-based matched cohort design.

SETTING

The Integrated Primary Care Information system, a general practitioners (GP) database in the Netherlands with a source population of 2.5 million inhabitants.

PARTICIPANTS

During the study period between 1 June 1996 and 1 January 2018, 8905 adults started methylphenidate and were matched to 10 non-users on sex, age, GP practice and ad prescription date. The total study population consisted of 97 198 participants.

MAIN OUTCOME MEASURES

Serious psychiatric events such as depression and suicide attempts, and overall mortality.

ANALYSES

Risks of development of each event during the use of methylphenidate were expressed as HR with 95% CI, adjusted for relevant confounders with methylphenidate as a time-dependent determinant. Additional adjustment was performed for the intervention ('intention-to-treat').

RESULTS

Although during follow-up, the unadjusted risks of depression and suicide attempt were strongly increased in users, depression and psychosis became non-significant after adjustment for alcohol-abuse and substance-abuse and psychiatric disease in the medical history and after adjustment for 'intention-to-treat'. However, the risk of suicide attempts remained significantly increased after full adjustment (HR 2.0; 95% CI 1.1 to 3.6), and was highest in women and in participants within the age-group of 18-40 years. The unadjusted risk of overall mortality was strongly increased, but this lowered to a significant 30% risk increase (HR 1.3; 95% CI 1.1 to 1.6) after full adjustment.

CONCLUSION

There is an increased risk of suicide attempts in adults up to 40 years of age after starting methylphenidate and this risk should be carefully considered before prescribing to this group.

Development of the ADFICE_IT models for predicting falls and recurrent falls in community-dwelling older adults: pooled analyses of European cohorts with special attention to medication

Background

Use of fall prevention strategies requires detection of high-risk patients. Our goal was to develop prediction models for falls and recurrent falls in community-dwelling older adults and to improve upon previous models by using a large, pooled sample and by considering a wide range of candidate predictors, including medications.

Methods

Harmonized data from 2 Dutch (LASA, B-PROOF) and 1 German cohort (ActiFE Ulm) of adults aged ≥65 years were used to fit 2 logistic regression models: one for predicting any fall and another for predicting recurrent falls over 1 year. Model generalizability was assessed using internal–external cross-validation.

Results

Data of 5 722 participants were included in the analyses, of whom 1 868 (34.7%) endured at least 1 fall and 702 (13.8%) endured a recurrent fall. Positive predictors for any fall were: educational status, depression, verbal fluency, functional limitations, falls history, and use of antiepileptics and drugs for urinary frequency and incontinence; negative predictors were: body mass index (BMI), grip strength, systolic blood pressure, and smoking. Positive predictors for recurrent falls were: educational status, visual impairment, functional limitations, urinary incontinence, falls history, and use of anti-Parkinson drugs, antihistamines, and drugs for urinary frequency and incontinence; BMI was a negative predictor. The average C-statistic value was 0.65 for the model for any fall and 0.70 for the model for recurrent falls.

Conclusion

Compared with previous models, the model for recurrent falls performed favorably while the model for any fall performed similarly. Validation and optimization of the models in other populations are warranted.

The interrelationship of chronic cough and depression: a prospective population-based study

Background

Chronic cough is a debilitating medical condition that is often complicated by psychomorbidities such as depressive symptoms. Nevertheless, little is known about the impact of chronic cough on the risk of developing depression. Therefore, we investigated the association between chronic cough and prevalent, incident and recurrent depression in a population-based sample of middle-aged and older persons.

Methods

Within the Rotterdam Study, a population-based cohort, we defined chronic cough as reporting daily coughing for ⩾3 months. Depression was assessed using the Center for Epidemiologic Studies Depression scale, clinical interviews and medical records. Associations between chronic cough and depression were determined with linear, logistic and Cox regression analyses.

Results

The study included 5877 participants (mean±sd age 72±8 years, 59% female) who contributed 37 287 person-years of follow-up. At baseline, participants with chronic cough reported more depressive symptoms (adjusted standardised mean difference 0.15, 95% CI 0.07–0.22) compared to those without chronic cough. Over time, chronic cough was associated with an increased risk of depression in participants with a history of depression (hazard ratio (HR) 1.45, 95% CI 1.13–1.84), but not in those without a history of depression (HR 0.91, 95% CI 0.68–1.22).

Conclusions

Adults with chronic cough have a disproportionate burden of depressive symptoms and an increased risk of recurrent depression. This highlights the importance of screening for depression in patients with chronic cough.

Adults with chronic cough have a disproportionate burden of depressive symptoms and are more likely to suffer recurrent depression, highlighting the need for screening for depression in individuals with chronic coughhttps://bit.ly/3sPvYTd

The interrelatedness of chronic cough and chronic pain

Since chronic cough has common neurobiological mechanisms and pathophysiology with chronic pain, both clinical disorders might be interrelated. Hence, we examined the association between chronic cough and chronic pain in adult subjects in the Rotterdam Study, a large prospective population-based cohort study.Using a standardised questionnaire, chronic pain was defined as pain lasting up to 6 months and grouped into a frequency of weekly/monthly or daily pain. Chronic cough was described as daily coughing for at least 3 months duration. The longitudinal and cross-sectional associations were investigated bi-directionally.Of 7141 subjects in the study, 54% (n=3888) reported chronic pain at baseline. The co-prevalence of daily chronic pain and chronic cough was 4.4%. Chronic cough was more prevalent in subjects with daily and weekly/monthly chronic pain compared with those without chronic pain (13.8% and 10.3% versus 8.2%; p<0.001). After adjustment for potential confounders, prevalent chronic pain was significantly associated with incident chronic cough (OR 1.47, 95% CI 1.08-1.99). The association remained significant in subjects with daily chronic pain (OR 1.49, 95% CI 1.06-2.11) with a similar effect estimate, albeit non-significant in those with weekly/monthly chronic pain (OR 1.43, 95% CI 0.98-2.10). After adjustment for covariables, subjects with chronic cough had a significant risk of developing chronic pain (OR 1.63, 95% CI 1.02-2.62) compared with those without chronic cough.Chronic cough and chronic pain confer risk on each other among adult subjects, indicating that both conditions might share common risk factors and/or pathophysiologic mechanisms.

Association between digoxin use and sudden cardiac death in individuals with the rs10494366 variant of the NOS1AP gene

Background

Digoxin is one of the oldest cardiovascular medications still used to treat heart failure and atrial fibrillation. Due to its narrow therapeutic window, it is associated with life threatening intoxication and arrhythmias, and with QTc-shortening. Common genetic variation in the nitric oxide synthase-1 adaptor protein (NOS1AP) has been associated with QTc interval prolongation.

Purpose

We investigated whether the rs10494366 variant of the NOS1AP gene modified the risk of SCD in patients using digoxin.

Methods

In a prospective population-based cohort study, we included data of the three cohorts, started as of January 1st, 1991 until January 1st 2014. Digoxin current use on the date of cardiac death in cases and the same day of follow-up in the remainder of the cohort was a time-dependent exposure. The main outcome was SCD defined as sudden and unexpected death as a result of cardiac causes, according to international criteria. Identification and adjudication of SCD was performed independently, before the start of this study. We used Cox proportional hazard regression analysis to investigate the associations between NOS1AP rs10494366 variant and incident SCD among digoxin users compared to non-users. Associations were adjusted for age, sex (model 1) in addition to BMI, prevalent diabetes, myocardial infarction, baseline hypertension and smoking status (past, current, never) (model 2).

Results

We included 14,594 individuals, with a mean age of 65.3 (SD 10.3) years. Almost 59% were female. The cumulative incidence of SCD was 9.5% (609 cases) by the end of follow up. Among them, 98 (16%) individuals were exposed to digoxin at the time of death.

In model 1, NOS1AP rs10494366 variant was not associated with SCD in the total study population. However, an interaction term of the gene with the daily dose of digoxin was significantly associated with increased risk of SCD (p-value 0.0001). In model 2, the risk of SCD in current users of digoxin was 4.2 [95% CI 1.3–13.8] for the GG genotype; 2.1 [95% CI 1.1–4.2] for the GT genotype, and 1.5 [95% CI 0.7–3.2] for the TT genotype.

Conclusion

NOS1AP rs10494366 variant modified the risk of sudden cardiac death in users of digoxin. Our study suggests that individuals with the homozygous minor GG allele have a fourfold increased risk of sudden cardiac death.

Funding Acknowledgement

Type of funding source: None

Emulating a target trial of statin use and risk of dementia using cohort data

OBJECTIVE

Observational data can be used to attempt to emulate a target trial of statin use and estimate analogues of intention-to-treat and per protocol effects on dementia risk.

METHODS

Using data from a prospective cohort study in the Netherlands, we conceptualized a sequence of "trials" in which eligible individuals ages 55-80 years were classified as statin initiators or noninitiators for every consecutive month between 1993 and 2007 and were followed until diagnosis of dementia, death, loss to follow-up, or the end of follow-up. We estimated 2 types of effects of statin use on dementia and a combined endpoint of dementia or death: the effect of initiation vs no initiation and the effect of sustained use vs no use. We estimated risk by statin treatment strategy over time via pooled logistic regression. We used inverse-probability weighting to account for treatment-confounder feedback in estimation of per-protocol effects.

RESULTS

Of 233,526 eligible person-trials (6,373 individuals), there were 622 initiators and 232,904 noninitiators. Comparing statin initiation with no initiation, the 10-year risk differences (95% confidence interval) were -0.1% (-2.3% to 1.8%) for dementia and 0.3% (-2.7% to 3.3%) for dementia or death. Comparing sustained statin use vs no use, the 10-year risk differences were -2.2% (-5.2% to 1.6%) for dementia and -5.1% (-10.5% to -1.1%) for dementia or death.

CONCLUSIONS

Individuals with sustained statin use, but not statin initiation alone, had reduced 10-year risks of dementia and dementia or death. Our results should be interpreted with caution due to the small number of initiators and events and potential for residual confounding.

Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9,925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross-sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5×10⁻⁸) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

Genome-wide association meta-analysis of 30,000 samples identifies seven novel loci for quantitative ECG traits

Genome-wide association studies (GWAS) of quantitative electrocardiographic (ECG) traits in large consortia have identified more than 130 loci associated with QT interval, QRS duration, PR interval, and heart rate (RR interval). In the current study, we meta-analyzed genome-wide association results from 30,000 mostly Dutch samples on four ECG traits: PR interval, QRS duration, QT interval, and RR interval. SNP genotype data was imputed using the Genome of the Netherlands reference panel encompassing 19 million SNPs, including millions of rare SNPs (minor allele frequency < 5%). In addition to many known loci, we identified seven novel locus-trait associations: KCND3, NR3C1, and PLN for PR interval, KCNE1, SGIP1, and NFKB1 for QT interval, and ATP2A2 for QRS duration, of which six were successfully replicated. At these seven loci, we performed conditional analyses and annotated significant SNPs (in exons and regulatory regions), demonstrating involvement of cardiac-related pathways and regulation of nearby genes.

Trends of prescribing antimicrobial drugs for urinary tract infections in primary care in the Netherlands: a population-based cohort study

OBJECTIVE

Urinary tract infections (UTIs) are an important reason to consult a general practitioner (GP). Here, we describe antimicrobial drug prescribing patterns for UTIs by GPs in relation to the Dutch primary care guidelines.

METHODS

We conducted a population-based cohort study in the Dutch Integrated Primary Care Information (IPCI)database, which encompasses approximately 2.5 million patients. All patients aged ≥12 years with at least 1 year of follow-up from 1996 to 2014 were extracted from the database. The number of prescriptions and choice of drug type were investigated over time and in different age categories. The choice of antimicrobial drug classes for UTIs and the duration of nitrofurantoin use in women were compared with the Dutch primary care guidelines of 1989, 1999, 2005 and 2013.

RESULTS

The source population comprised 1 755 085 patients who received 2 019 335 antimicrobial drug prescriptions; 401 655 (35.1%) prescriptions were for UTIs (45.2% in women and 12.6% in men). The proportion of prescriptions for UTIs within all prescriptions with an indication code increased from 5.2% in 1996 to 14% in 2014 in men and from 28% in 1996 to 50% in 2014 in women. In men, UTIs were most frequently treated with fluoroquinolones during the entire study period, whereas fluoroquinolones were only advised as first choice in the latest guideline of 2013. In women, UTIs were increasingly (p<0.05) treated with nitrofuran derivatives with a statistically significant difference after implementation of the guideline of 2005. Compliance to the advised duration of nitrofurantoin prescriptions in women has increased since the guideline of 2005.

CONCLUSIONS

Antimicrobial drug prescribing for UTIs seemed to have increased over time. Prescribing in line with the UTI guidelines increased with regard to choice and duration of antimicrobial drugs. We showed that databases like IPCI, in which prescription and indication are monitored, can be valuable antibiotic stewardship tools.

Sarcopenia and Its Clinical Correlates in the General Population: The Rotterdam Study

Sarcopenia, a complex multifactorial condition, is characterized by loss of muscle mass and function, which increases progressively with age. The existence of different definitions has contributed to the large variation in the prevalence estimates of sarcopenia. We aimed to estimate the prevalence of sarcopenia in the general population using the European Working Group on Sarcopenia in Older People (EWGSOP) proposed definition and compared baseline demographic and clinical characteristics between the nonsarcopenia, presarcopenia, and sarcopenia individuals, with particular emphasis on the overlap with osteoporosis and fracture risk. We studied 5911 subjects at a mean age of 69.2 years (55.8% female) with data on sarcopenia participating in the Rotterdam Study, a prospective population-based cohort study in Rotterdam, the Netherlands. Presarcopenia was defined as having only low muscle mass, whereas sarcopenia was defined based on the presence of low muscle mass, plus either low muscle strength or low physical performance. The prevalence of presarcopenia and sarcopenia was 5.9% and 4.4%, respectively. Individuals with sarcopenia were older, more often males, smokers, with less optimal dietary intake, and more often disabled with lower physical activity. Although the prevalence of fractures was higher in individuals with low lean mass (presarcopenic [16.6%] and sarcopenic [23.5%]) compared with the no sarcopenic group (15.5%), the differences were not present after correcting for age and sex. There were no statistical differences in the prevalence of chronic diseases, with the exception of a higher prevalence of COPD in presarcopenic (29.1%) and sarcopenic (26.9%) individuals compared with nonsarcopenic (13.4%) individuals. Osteoporotic individuals with (odds ratio [OR] = 2.59, 95% confidence interval [CI] 1.41-4.45) and without sarcopenia (OR = 2.75, 95% CI 2.01-3.75) had similar elevated risk of nonvertebral fractures. The presence of sarcopenia appears to be independent of chronic diseases with the exception of COPD and more related to lifestyle factors and disabilities. Sarcopenic individuals in the general population are at no greater risk of fracture than what is determined by their low bone mineral density. © 2018 American Society for Bone and Mineral Research.

Characteristics of Anticoagulant Therapy and Comorbidity Related to Overanticoagulation

The risk of hemorrhage when using coumarin anticoagulants sharply increases when the International Normalised Ratio (INR) is ≥6.0. We performed a prospective cohort study with a nested case-control design among 17,056 outpatients of an anticoagulation clinic to determine the incidence of overanticoagulation and to study the association between overanticoagulation and characteristics of anticoagulant therapy and comorbidity. The incidence rate of an INR ≥6.0 was 7.8 per 10,000 treatment days in prevalent users on the starting date and 22.5 per 10,000 treatment days in incident users during the study period. 300 cases with an INR ≥6.0 were compared with 302 randomly selected matched controls with an INR within the target zone. Patients on acenocoumarol had an increased risk of an INR ≥6.0 compared to patients on phenprocoumon. Regarding comorbidity, impaired liver function, congestive heart failure, diarrhea and fever were risk factors for overanticoagulation. Increased monitoring of INR values if risk factors are present or avoidance of risk factors could prevent excess anticoagulation and potential bleeding complications.

Design of a frailty index among community living middle-aged and older people: The Rotterdam study

OBJECTIVES

To design a frailty index (FI) and evaluate three methods to handle missing data. Furthermore, we evaluated its construct (i.e., skewed distribution, correlation with age and sub-maximum score) and criterion validity (based on mortality risk).

STUDY DESIGN

We included 11,539 participants (45± years) from a population-based cohort in the Netherlands. Frailty was measured with a FI, which we constructed based on the accumulation of 45 health-related variables, related to mood, cognition, functional status, diseases and conditions, biomarkers, and nutritional status. A total FI-score was calculated by averaging the scores of the deficits, resulting in a score between 0 and 1, with higher scores indicating increasing frailty. Mean imputation, single- and multiple imputation were applied.

MAIN OUTCOME MEASURE

Mortality data were obtained by notification from the municipal administration. Median follow-up time was 9.5 years, during which 3902 (34%) participants died.

RESULTS

The median FI for the full population was 0.16 (IQR=0.11-0.23). The distribution of the FI was slightly right-skewed, the absolute maximum score was 0.78 and there was a strong correlation with age (Pearson correlation=0.52;95%CI=0.51-0.54). The adjusted HR per unit increase in FI-score on mortality was 1.05 (95%CI=1.05-1.06). Multiple imputation seemed to provide more robust results than mean imputation.

CONCLUSION

Based on our results we advise to the use of at least 30 deficits from different health domains to construct a FI if data are not imputed. Future research should use the continuous nature of the FI to monitor trajectories in frailty and find preventive strategies.

Causality of Drugs Involved in Acute Liver Failure Leading to Transplantation: Results from the Study of Acute Liver Transplant (SALT)

BACKGROUND

Several methods have been proposed to assess causality in drug-induced liver injury but none have been tested in the specific context of acute liver failure leading to transplantation (ALFT).

OBJECTIVE

We took advantage of the Study of Acute Liver Transplant (SALT), a European case-population study of ALFT, to test different causality scales.

METHODS

Causality was assessed by experts in SALT, a 7-country case-population study from 2005 to 2007 of adult otherwise unexplained ALFT, for all drugs found within 30 days prior to the date of initial symptoms of liver disease (index date), using information content, causality scales, and data circuit determined from a pilot study, Salome.

RESULTS

The consensus points from Salome were to provide full data on drugs including international non-proprietary name (INN) and doses except for non-steroidal anti-inflammatory drugs (NSAIDs) and to use the World Health Organization (WHO) causality scale. In SALT, among the 9,479 identified patients, 600 (6.3%) were cases of ALFT, of which 187 had been exposed to drugs within 30 days, without overdose. In 130 (69.5%) of these the causality score was possible, probable, or highly probable.

CONCLUSION

In ALFT cases, once other clinical causes have been excluded and drug exposure established within 30 days, the main discriminant characteristic for causality will be previous knowledge of possible hepatotoxicity.

Association of Serum Thyrotropin with Anthropometric Markers of Obesity in the General Population

BACKGROUND

Except from associations study with body weight, there are few longitudinal data regarding the association between thyroid function and anthropometric measurements such as waist circumference, waist-to-hip ratio, or waist-to height ratio.

OBJECTIVE

This study aimed to investigate the association of thyrotropin (TSH) at baseline with changes in different anthropometric markers between baseline and follow-up in the general population.

METHOD

Data were used from four population-based longitudinal cohort studies and one population-based cross-sectional study. A total of 16,902 (8204 males) subjects aged 20-95 years from the general population were studied. Body mass index, waist circumference, waist-to-hip ratio, and waist-to-height ratio were measured. Multivariable median regression models were calculated adjusting for the following covariates: age, sex, baseline value of the respective anthropometric marker, smoking status, follow-up-time period, and study site.

RESULTS

In cross-sectional analyses, serum TSH within the reference range was positively associated with waist circumference (β = 0.94 cm [confidence interval (CI) 0.56-1.32]) and waist-to-height-ratio (β = 0.029 [CI 0.017-0.042]). These associations were also present for the full range of TSH. In the longitudinal analyses, serum TSH at baseline was inversely associated with a five-year change of all considered anthropometric measures within the prior defined study-specific reference range, as well as in the full range of serum TSH.

CONCLUSION

High TSH serum levels were positively associated with current anthropometric markers, even in the study-specific reference ranges. In contrast, high TSH serum levels were associated with decreased anthropometric markers over a time span of approximately five years. Further research is needed to determine possible clinical implications as well as public health consequences of these findings.

Abstract 4482: A new quantification method for assessment of plasma concentrations of pemetrexed and its polyglutamate metabolites

Pemetrexed (PMTX) is a multi-targeted antifolate drug applied in the treatment of diseases such as malignant pleural mesothelioma and non-small cell lung cancer. Assessment of therapeutic plasma drug and drug metabolite concentrations offers a useful tool for monitoring drug dosage, avoiding drug toxicity and obtaining therapeutic efficacy.

Stock solutions of synthesized PMTX and its (poly)-glutamyl metabolites (PMTXPG1-3), as well as their corresponding heavy labeled analogues (13C5, 15N (6 Da mass difference)) were prepared and spiked into plasma from healthy donors, and 2 M trichloroacetic acid (TCA) was added for protein precipitation. The samples were centrifuged at 5223 g and subsequently the supernatant was taken for measurement on a UHPLC-QqQ mass spectrometry set-up. After assessment of analytical factors such as linear response, stability, reproducibility and recovery, plasma of 4 non-small cell cancer patients undergoing PMTX treatment were measured to establish the methods ability for measuring clinically relevant concentrations.

The stability of patient samples stored at -80°C was monitored during a six month period, in which no statistically significant change in recovery between them (all recoveries were between 97-101%, no trend of decrease in time) was observed. The recovery of PMTX and its metabolites after the sample pretreatment procedure ranged between 45% and 79%. The relative standard deviations (RSD) in the biological replicates of the reproducibility analysis were 7.9% for PMTX, 5.9% for PMTXPG1, 7.2% for PMTXPG2 and 37.9% for PMTXPG3. For all analytes the linear response was determined over three orders of magnitude in concentration (0.2 to 500 nmol/L). Additionally, the limit of quantification (lowest quantifiable concentration (RSD &lt; 20%)) was determined for all analytes. For PMTX, PMTXPG1 and PMTXPG2 subnanomolar limits of quantification were determined. The linear response for the compounds was determined by calculation of the correlation coefficient, which was better than 0.99 for all four analytes. In all four PMTX-treated patients the plasma concentrations of PMTX, PMTXPG1 and PMTXPG2 could be detected and quantified. PMTXPG3 was not detected in any of the tested clinical samples of the four patients.

In conclusion, a LC-MS/MS-based method to measure PMTX and its polyglutamate metabolites with minimal sample pretreatment is described. To our knowledge this is the first time measurement method for pemetrexed metabolites in human plasma is reported. The method also has relatively short measurement times and good performance in being able to quantify the drug and two of its metabolites at clinically relevant concentrations in plasma of patients with lung carcinoma.

Citation Format: Marcel Stoop, Sabine Visser, Evert van Dijk, Bruno Stricker, Theo Luider, Joachim Aerts. A new quantification method for assessment of plasma concentrations of pemetrexed and its polyglutamate metabolites. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4482. doi:10.1158/1538-7445.AM2015-4482

Liver transplant associated with paracetamol overdose: results from the seven-country SALT study

AIMS

Acute drug overdose, especially with paracetamol, may cause acute liver failure leading to registration for transplantation (ALFT). Population statistics and between-country differences for ALFT related to overdose have been poorly described. The aim of the present study was to evaluate overdose ALFT in the multi-country Study of Acute Liver Transplantation (SALT).

METHODS

All adult overdose-related ALFT, with or without suicidal intent, in France, Greece, Ireland, Italy, the Netherlands, Portugal and the UK between 2005 and 2007 were identified from liver transplant registries and hospital records. These were compared with whole-country and per capita use of paracetamol.

RESULTS

Six hundred cases of ALFT were identified in 52 of 57 eligible transplant centres, of which 114 involved overdose (72 intentional, 10 non-intentional, 32 uncertain). Overdose represented 20% of all-cause ALFT: Ireland 52%, UK 28%, France 18%, the Netherlands 8%, and Italy 1%. Overdose ALFT were mostly females (61%), mean age 33.6 ± 10.9 years. A total of 111 (97%) of the overdoses involved paracetamol. Event rates ranged from one ALFT for 20.7 tons of paracetamol in Ireland, to one for 1074 tons in Italy and one case in 60 million inhabitants over 3 years in Italy to one case in 286 000 inhabitants per year in Ireland. Per-country event rates for non-overdose ALFT exposed to paracetamol were between 2.5 and 4.0 per million treatment-years sold.

CONCLUSIONS

Paracetamol overdose was found to represent one-sixth of all-cause ALFT. There was a 50-fold difference in Europe in the rates of paracetamol overdose ALFT, and a 200-fold difference per million inhabitants.

Methodology for a multinational case-population study on liver toxicity risks with NSAIDs: the Study of Acute Liver Transplant (SALT)

PURPOSE

The European Committee for Human Medicinal Products (CHMP) requested a multinational study with the aim to investigate the risk of acute liver failure (ALF) leading to registration for transplantation in patients exposed to non-steroidal anti-inflammatory drugs (NSAIDs). The method of this multinational, multicentre, retrospective case-population study, named SALT (Study of Acute Liver Transplant), is documented here.

METHODS

This was a multicentre, multinational retrospective case-population study performed in France, Italy, Portugal, Greece, Ireland, the Netherlands and the UK. The study period was 3 years (1 January 2005-31 December 2007). Cases were patients ≥ 18 years of age with ALF at the time of registration on the transplant list for liver transplantation who had been exposed to an NSAID within 30 days preceding the initial symptoms of liver disease (index date). Exposure was defined as exposure to any NSAID. Per country rates of NSAID-exposed transplantation-registered ALF were computed as the ratio of the number of cases identified in the country to total population exposure. Overall and per-drug sales for NSAIDs and for paracetamol were obtained from Intercontinental Marketing Services (IMS) Health for all participating countries. Population exposure was measured as the defined daily dose and as estimated annual number of patients exposed (primary endpoint) with 95 % confidence intervals.

RESULTS

The study protocol was approved by the CHMP. Of the 57 eligible liver transplant centres, 54 agreed to participate in the study. All national authorizations were received with relevant administrative burden, mainly due to bureaucracy.

CONCLUSION

The present study created a multinational research network to estimate population-based absolute rates of drug-exposed ALF leading to registration on the transplantation list. This study design was chosen to obtain a fast response to a public health issue, namely, that of an increased risk of a rare, very serious adverse reaction. This model could be used to study other drug-related issues in ALF.

Changes in HDL cholesterol and cardiovascular outcomes after lipid modification therapy

BACKGROUND

Lipid modification therapy (LMT) produces cardiovascular benefits principally through reductions in low density lipoprotein cholesterol. While recent evidence, using data from 454 participants in the Framingham Offspring Study, has suggested that increases in high density lipoprotein cholesterol (HDL-C) are also associated with a reduction in cardiovascular outcomes, independently of changes in low density lipoprotein cholesterol, replication of this finding is important. The authors therefore present further results using data from the EPIC-Norfolk (UK) and Rotterdam (The Netherlands) prospective cohort studies.

METHODS

A total of 1148 participants, 446 from the EPIC-Norfolk and 702 from the Rotterdam study, were assessed for lipids before and after starting LMT. Subsequent risk of cardiovascular events, ascertained through linkage with mortality records and hospital databases, was investigated using Cox proportional hazards regression. Random effects meta-analysis was used to combine results across studies.

RESULTS

Based on combined data from the EPIC-Norfolk and Rotterdam studies there was some evidence that change in HDL-C resulting from LMT was associated with reduced cardiovascular risk (HR per pooled SD (=0.34 mmol/l) increase=0.74, 95% CI 0.56 to 0.99, adjusted for age, sex and baseline HDL-C). However, this association was attenuated and was not (statistically) significant with further adjustments for non-HDL-C and for cigarette smoking history, prevalent diabetes, systolic blood pressure, body mass index, use of antihypertensive medication, previous myocardial infarction, prevalent angina and previous stroke (0.92, 0.701.20).

CONCLUSIONS

Following adjustment for conventional non-lipid risk factors of cardiovascular disease, this study provides no evidence to support a significant benefit from increasing HDL-C independent of the effect of lowering non-HDL-C.

Abstract 5600: Genetic variants associated with reproductive aging and the risk of breast cancer

Early menarche and later menopause are well-established risk factors for breast cancer. Recent genome-wide association studies have identified several novel loci for these two traits. However, the association between these loci and breast cancer risk remains unknown. In this study, we investigated 19 and 17 newly identified SNPs from ReproGen Consortium that were associated with age at menarche and age at natural menopause, respectively, and assessed their association with breast cancer in 6 population-based studies. We further used these SNPs to calculate genetic risk scores (GRSs) based on their association with each trait. After adjustment for age and potential population stratification, two age-at -menarche associated SNPs (rs1079866 and rs7821178) and one age-at-natural-menopause associated SNP (rs2517388) were associated with an increased risk of breast cancer (p values, 0.003, 0.009 and 0.023, respectively); although overall we did not observe significant association between the GRSs and breast cancer risk, the 4th and 5th highest quintile of the menarche GRS had relative ratios of 1.14 (CI, 1.01 to 1.28) and 1.13 (CI, 1.00 to 1.27), respectively, compared to the lowest quintile; and these associations did not appear to be attenuated by controlling for age at menarche, age at natural menopause, or other conventional risk factors. Our study suggested that three genetic variants, independent of their association with onset of menarche or natural menopause, were associated with breast cancer risk, and a GRS that combines multiple menarche-associated SNPs might be useful for identifying a high risk subgroup for breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5600. doi:10.1158/1538-7445.AM2011-5600

Multiple genetic loci influence serum urate levels and their relationship with gout and cardiovascular disease risk factors

BACKGROUND

Elevated serum urate levels can lead to gout and are associated with cardiovascular risk factors. We performed a genome-wide association study to search for genetic susceptibility loci for serum urate and gout and investigated the causal nature of the associations of serum urate with gout and selected cardiovascular risk factors and coronary heart disease (CHD).

METHODS AND RESULTS

Meta-analyses of genome-wide association studies (GWAS) were performed in 5 population-based cohorts of the Cohorts for Heart and Aging Research in Genome Epidemiology consortium for serum urate and gout in 28 283 white participants. The effect of the most significant single-nucleotide polymorphism at all genome-wide significant loci on serum urate was added to create a genetic urate score. Findings were replicated in the Women's Genome Health Study (n=22 054). Single-nucleotide polymorphisms at 8 genetic loci achieved genome-wide significance with serum urate levels (P=4×10(-8) to 2×10(-242) in SLC22A11, GCKR, R3HDM2-INHBC region, RREB1, PDZK1, SLC2A9, ABCG2, and SLC17A1). Only 2 loci (SLC2A9, ABCG2) showed genome-wide significant association with gout. The genetic urate score was strongly associated with serum urate and gout (odds ratio, 12.4 per 100 μmol/L; P=3×10(-39)) but not with blood pressure, glucose, estimated glomerular filtration rate, chronic kidney disease, or CHD. The lack of association between the genetic score and the latter phenotypes also was observed in the Women's Genome Health Study.

CONCLUSIONS

The genetic urate score analysis suggested a causal relationship between serum urate and gout but did not provide evidence for one between serum urate and cardiovascular risk factors and CHD.

Genome-wide association meta-analysis for total serum bilirubin levels

Variation in serum bilirubin is associated with altered cardiovascular disease risk and drug metabolism. We aimed to identify genetic contributors to variability in serum bilirubin levels by combining results from three genome-wide association studies (Framingham heart study, n = 3424; Rotterdam study, n = 3847; Age, Gene, Environment and Susceptibility-Reykjavik, n = 2193). Meta-analysis showed strong replication for a genetic influence on serum bilirubin levels of the UGT1A1 locus (P < 5 x 10(-324)) and a 12p12.2 locus. The peak signal in the 12p12.2 region was a non-synonymous SNP in SLCO1B1 (rs4149056, P = 6.7 x 10(-13)), which gives rise to a valine to alanine amino acid change leading to reduced activity for a hepatic transporter with known affinity for bilirubin. There were also suggestive associations with several other loci. The top variants in UGT1A1 and SLCO1B1 explain approximately 18.0 and approximately 1.0% of the variation in total serum bilirubin levels, respectively. In a conditional analysis adjusted for individual genotypes for the top UGT1A1 variant, the top SLCO1B1 variant remained highly significant (P = 7.3 x 10(-13)), but no other variants achieved genome-wide significance. In one of the largest genetic studies of bilirubin to date (n = 9464), we confirm the substantial genetic influence of UGT1A1 variants, consistent with past linkage and association studies, and additionally provide strong evidence of a role for allelic variation in SLCO1B1. Given the involvement of bilirubin in a number of physiological and disease processes, and the roles for UGT1A1 and SLCO1B1 in drug metabolism, these genetic findings have potential clinical importance. In analyses for association with gallbladder disease or gallstones, top bilirubin SNPs in UGT1A1 and SLCO1B1 were not associated.