Objectives

This study aims to assess whether digoxin has a different effect on mortality risk for women than it does for men in patients with heart failure (HF).

Design

This study uses the UK-based The Health Information Network population database in a cohort study of the impact of digoxin exposure on mortality for men and women who carry the diagnosis of HF. Digoxin exposure was assessed based on prescribing data. Multivariable Cox proportional hazards models were used to assess whether there was an interaction between sex and digoxin affecting mortality hazard.

Setting

The setting was primary care outpatient practices.

Participants

The study cohort consisted of 17 707 men and 19 227 women with the diagnosis of HF who contributed only time without digoxin exposure and 9487 men and 10 808 women with the diagnosis of HF who contributed time with digoxin exposure.

Main outcome measures

The main outcome measure was all-cause mortality.

Results

The primary outcome of this study was the absence of a large interaction between digoxin use and sex affecting mortality. For men, digoxin use was associated with a HR for mortality of 1.00, while for women, the HR was also 1.00 (p value for interaction 0.65). The results of sensitivity analyses were consistent with those of the primary analysis.

Conclusion

Observational data do not support the concern that there is a substantial increased risk of mortality due to the use of digoxin in women. This finding is consistent with previous observational studies but discordant with results from a post hoc analysis of a randomised controlled trial of digoxin versus placebo.

Article summary

Article focus

Digoxin is used in patients with HF and has been shown in one major randomised control trial, the Digitalis Investigation Group study, to reduce the rate of hospitalisations in that population.

Post hoc analysis of Digitalis Investigation Group indicated that digoxin, when used in the treatment of HF, may increase mortality by approximately 20% in women but not in men. Further randomised trials evaluating the interaction between digoxin and sex have not emerged.

Key messages

For men, digoxin use was associated with a HR for mortality of 1.00, while for women, the HR was also 1.00 (p value for interaction 0.65). There was no evidence of a different association between digoxin use and mortality in women compared with men. Sensitivity analyses did not affect this estimate materially.

An interesting incidental finding of this study is that interventions known to reduce mortality in HF are used less in women than in men who have been diagnosed with HF.

Strengths and limitations of this study

The major strength of this study was its large sample size, which allowed adjustment for many covariates and numerous sensitivity analyses, none of which affected the conclusions.

The major limitation of this study is that it is non-randomised. Although there is no evidence of substantial confounding of the main study result, confounding could still bias these results.

The inflammatory bowel diseases (IBD) Crohn’s disease and ulcerative colitis are common causes of morbidity in children and young adults in the western world. Here we report the results of a genome-wide association study in early-onset IBD involving 3,426 affected individuals and 11,963 genetically matched controls recruited through international collaborations in Europe and North America, thereby extending the results from a previous study of 1,011 individuals with early-onset IBD1. We have identified five new regions associated with early-onset IBD susceptibility, including 16p11 near the cytokine gene IL27 (rs8049439, P = 2.41 × 10−9), 22q12 (rs2412973, P = 1.55 × 10−9), 10q22 (rs1250550, P = 5.63 × 10−9), 2q37 (rs4676410, P = 3.64 × 10−8) and 19q13.11 (rs10500264, P = 4.26 × 10−10). Our scan also detected associations at 23 of 32 loci previously implicated in adult-onset Crohn’s disease and at 8 of 17 loci implicated in adult-onset ulcerative colitis, highlighting the close pathogenetic relationship between early- and adult-onset IBD.

Major depressive disorder (MDD) is a common psychiatric and behavioral disorder. To discover novel variants conferring risk to MDD, we conducted a whole-genome scan of copy number variation (CNV), including 1,693 MDD cases and 4,506 controls genotyped on the Perlegen 600K platform. The most significant locus was observed on 5q35.1, harboring the SLIT3 gene (P = 2×10−3). Extending the controls with 30,000 subjects typed on the Illumina 550 k array, we found the CNV to remain exclusive to MDD cases (P = 3.2×10−9). Duplication was observed in 5 unrelated MDD cases encompassing 646 kb with highly similar breakpoints. SLIT3 is integral to repulsive axon guidance based on binding to Roundabout receptors. Duplication of 5q35.1 is a highly penetrant variation accounting for 0.7% of the subset of 647 cases harboring large CNVs, using a threshold of a minimum of 10 SNPs and 100 kb. This study leverages a large dataset of MDD cases and controls for the analysis of CNVs with matched platform and ethnicity. SLIT3 duplication is a novel association which explains a definitive proportion of the largely unknown etiology of MDD.

Autism spectrum disorders (ASDs) are childhood neurodevelopmental disorders with complex genetic origins1–4. Previous studies focusing on candidate genes or genomic regions have identified several copy number variations (CNVs) that are associated with an increased risk of ASDs5–9. Here we present the results from a whole-genome CNV study on a cohort of 859 ASD cases and 1,409 healthy children of European ancestry who were genotyped with ~550,000 single nucleotide polymorphism markers, in an attempt to comprehensively identify CNVs conferring susceptibility to ASDs. Positive findings were evaluated in an independent cohort of 1,336 ASD cases and 1,110 controls of European ancestry. Besides previously reported ASD candidate genes, such as NRXN1 (ref. 10) and CNTN4 (refs 11, 12), several new susceptibility genes encoding neuronal cell-adhesion molecules, including NLGN1 and ASTN2, were enriched with CNVs in ASD cases compared to controls (P = 9.5 × 10−3). Furthermore, CNVs within or surrounding genes involved in the ubiquitin pathways, including UBE3A, PARK2, RFWD2 and FBXO40, were affected by CNVs not observed in controls (P = 3.3 × 10−3). We also identified duplications 55 kilobases upstream of complementary DNA AK123120 (P = 3.6 × 10−6). Although these variants may be individually rare, they target genes involved in neuronal cell-adhesion or ubiquitin degradation, indicating that these two important gene networks expressed within the central nervous system may contribute to the genetic susceptibility of ASD.

OBJECTIVE

The purpose of this study was to test the hypothesis that bezafibrate, an approved fibrate, can prevent or delay type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was a retrospective cohort study using data from routine medical practice in the U.K., as captured by the General Practice Research Database (GPRD). Individuals chronically exposed to bezafibrate were compared with individuals chronically exposed to other fibrates. Hazard ratios (HRs) for incident type 2 diabetes were calculated using a Cox proportional hazards model. A post hoc analysis was used to examine the effect of bezafibrate on progression to use of oral antidiabetic medications or insulin in individuals with diabetes at baseline.

RESULTS

Bezafibrate users had a lower hazard for incident diabetes than users of other fibrates (HR 0.66 [95% CI 0.53–0.81]). This effect became stronger with increasing duration of therapy. Post hoc analysis of the effect of bezafibrate on progression of preexisting diabetes also showed a lower hazard for progression to use of antidiabetic medication (0.54 [0.38–0.76]) or progression to use of insulin (0.78 [0.55–1.10]).

CONCLUSIONS

Bezafibrate appears to have clinically important antidiabetic properties. Randomized controlled trials should be considered to assess the utility of bezafibrate in treating patients with diabetes or in preventing diabetes in high-risk patients.