Metformin Cessation and Dementia Incidence

Importance

Prior studies suggested that metformin may be associated with reduced dementia incidence, but associations may be confounded by disease severity and prescribing trends. Cessation of metformin therapy in people with diabetes typically occurs due to signs of kidney dysfunction but sometimes is due to less serious adverse effects associated with metformin.

Objective

To investigate the association of terminating metformin treatment for reasons unrelated to kidney dysfunction with dementia incidence.

Design, Setting, and Participants

This cohort study was conducted at Kaiser Permanente Northern California, a large integrated health care delivery system, among a cohort of metformin users born prior to 1955 without history of diagnosed kidney disease at metformin initiation. Dementia follow-up began with the implementation of electronic health records in 1996 and continued to 2020. Data were analyzed from November 2021 through September 2023.

Exposures

A total of 12 220 early terminators, individuals who stopped metformin with normal estimated glomerular filtration rate (eGFR), were compared with routine metformin users, who had not yet terminated metformin treatment or had terminated (with or without restarting) after their first abnormal eGFR measurement. Early terminators were matched with routine users of the same age and gender who had diabetes for the same duration.

Main outcomes and measures

The outcome of interest was all-cause incident dementia. Follow-up for early terminators and their matched routine users was started at age of termination for the early terminator. Survival models adjusted for sociodemographic characteristics and comorbidities at the time of metformin termination (or matched age). Mediation models with HbA1c level and insulin usage 1 and 5 years after termination tested whether changes in blood glucose or insulin usage explained associations between early termination of metformin and dementia incidence.

Results

The final analytic sample consisted of 12 220 early terminators (5640 women [46.2%]; mean [SD] age at start of first metformin prescription, 59.4 [9.0] years) and 29 126 routine users (13 582 women [46.6%]; mean [SD] age at start of first metformin prescription, 61.1 [8.9] years). Early terminators had 1.21 times the hazard of dementia diagnosis compared with routine users (hazard ratio, 1.21; 95% CI, 1.12 to 1.30). In mediation analysis, contributions to this association by changes in HbA1c level or insulin use ranged from no contribution (0.00 years; 95% CI, -0.02 to 0.02 years) for insulin use at 5 years after termination to 0.07 years (95% CI, 0.02 to 0.13 years) for HbA1c level at 1 year after termination, suggesting that the association was largely independent of changes in HbA1c level and insulin usage.

Conclusions and Relevance

In this study, terminating metformin treatment was associated with increased dementia incidence. This finding may have important implications for clinical treatment of adults with diabetes and provides additional evidence that metformin is associated with reduced dementia risk.

Dyslipidemia, inflammation, calcification, and adiposity in aortic stenosis: a genome-wide study

AIMS

Although highly heritable, the genetic etiology of calcific aortic stenosis (AS) remains incompletely understood. The aim of this study was to discover novel genetic contributors to AS and to integrate functional, expression, and cross-phenotype data to identify mechanisms of AS.

METHODS AND RESULTS

A genome-wide meta-analysis of 11.6 million variants in 10 cohorts involving 653 867 European ancestry participants (13 765 cases) was performed. Seventeen loci were associated with AS at P ≤ 5 × 10-8, of which 15 replicated in an independent cohort of 90 828 participants (7111 cases), including CELSR2-SORT1, NLRP6, and SMC2. A genetic risk score comprised of the index variants was associated with AS [odds ratio (OR) per standard deviation, 1.31; 95% confidence interval (CI), 1.26-1.35; P = 2.7 × 10-51] and aortic valve calcium (OR per standard deviation, 1.22; 95% CI, 1.08-1.37; P = 1.4 × 10-3), after adjustment for known risk factors. A phenome-wide association study indicated multiple associations with coronary artery disease, apolipoprotein B, and triglycerides. Mendelian randomization supported a causal role for apolipoprotein B-containing lipoprotein particles in AS (OR per g/L of apolipoprotein B, 3.85; 95% CI, 2.90-5.12; P = 2.1 × 10-20) and replicated previous findings of causality for lipoprotein(a) (OR per natural logarithm, 1.20; 95% CI, 1.17-1.23; P = 4.8 × 10-73) and body mass index (OR per kg/m2, 1.07; 95% CI, 1.05-1.9; P = 1.9 × 10-12). Colocalization analyses using the GTEx database identified a role for differential expression of the genes LPA, SORT1, ACTR2, NOTCH4, IL6R, and FADS.

CONCLUSION

Dyslipidemia, inflammation, calcification, and adiposity play important roles in the etiology of AS, implicating novel treatments and prevention strategies.

Polygenic Risk Score and Statin Relative Risk Reduction for Primary Prevention of Myocardial Infarction in a Real-World Population

Genetic substudies of randomized controlled trials demonstrate that high coronary heart disease (CHD) polygenic risk score modifies statin CHD relative risk reduction; it is unknown if the association extends to statin users undergoing routine care. We sought to determine how statin effectiveness is modified by CHD polygenic risk score in a real-world cohort of participants without previous myocardial infarction. We determined CHD polygenic risk scores in participants of the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort. Covariate-adjusted Cox regression models were used to compare the risk of cardiovascular outcomes between statin users and matched nonusers. Statin effectiveness on incident myocardial infarction showed no gradient with increasing 10-year Pooled Cohort Equations atherosclerotic cardiovascular disease (ASCVD) risk across low, borderline, intermediate, and high ASCVD risk score groups. In contrast, statin effectiveness by polygenic risk was largest in the high polygenic risk score group (hazard ratio (HR) 0.41, 95% confidence interval (CI), 0.31-0.53; P = 1.5E-11), intermediate in the intermediate polygenic risk score group (HR 0.56, 95% CI, 0.47-0.66; P = 8.4E-12), and smallest in the low polygenic risk score group (HR 0.67, 95% CI, 0.47-0.97; P = 0.03; P for high vs. low = 0.01). ASCVD risk and statin low-density lipoprotein cholesterol (LDL-C) lowering did not differ across polygenic risk score groups. In patients undergoing routine care, CHD polygenic risk modified statin relative risk reduction of incident myocardial infarction independent of LDL-C lowering. Our findings extend prior work by identifying a subset (i.e., self-identified White individuals with low CHD polygenic risk scores) with attenuated clinical benefit from statins.

A Large-Scale Association Study Detects Novel Rare Variants, Risk Genes, Functional Elements, and Polygenic Architecture of Prostate Cancer Susceptibility

To identify rare variants associated with prostate cancer susceptibility and better characterize the mechanisms and cumulative disease risk associated with common risk variants, we conducted an integrated study of prostate cancer genetic etiology in two cohorts using custom genotyping microarrays, large imputation reference panels, and functional annotation approaches. Specifically, 11,984 men (6,196 prostate cancer cases and 5,788 controls) of European ancestry from Northern California Kaiser Permanente were genotyped and meta-analyzed with 196,269 men of European ancestry (7,917 prostate cancer cases and 188,352 controls) from the UK Biobank. Three novel loci, including two rare variants (European ancestry minor allele frequency < 0.01, at 3p21.31 and 8p12), were significant genome wide in a meta-analysis. Gene-based rare variant tests implicated a known prostate cancer gene (HOXB13), as well as a novel candidate gene (ILDR1), which encodes a receptor highly expressed in prostate tissue and is related to the B7/CD28 family of T-cell immune checkpoint markers. Haplotypic patterns of long-range linkage disequilibrium were observed for rare genetic variants at HOXB13 and other loci, reflecting their evolutionary history. In addition, a polygenic risk score (PRS) of 188 prostate cancer variants was strongly associated with risk (90th vs. 40th-60th percentile OR = 2.62, P = 2.55 × 10-191). Many of the 188 variants exhibited functional signatures of gene expression regulation or transcription factor binding, including a 6-fold difference in log-probability of androgen receptor binding at the variant rs2680708 (17q22). Rare variant and PRS associations, with concomitant functional interpretation of risk mechanisms, can help clarify the full genetic architecture of prostate cancer and other complex traits. SIGNIFICANCE: This study maps the biological relationships between diverse risk factors for prostate cancer, integrating different functional datasets to interpret and model genome-wide data from over 200,000 men with and without prostate cancer.See related commentary by Lachance, p. 1637.

Abstract GS2-05: Genome-wide association study identifies UACA as a modulator of breast cancer chemoresistance and survival

Prior studies suggest a strong genetic influence on breast cancer prognosis. Six genome-wide association studies (GWAS) on breast cancer prognosis have been published to date. However, none of the reported loci was replicated across studies and only two passed genome-wide significance (P &lt; 5 x 10-8). In the Pathways Study, a prospective cohort of breast cancer survivors begun in Kaiser Permanente Northern California (KPNC) in 2006, we carried out a GWAS of overall survival (OS) in 3,973 patients. Trans-ethnic meta-GWAS identified an association with OS of a locus on chromosome 15 that almost reached genome-wide significance (P = 9.42 x 10-8). This locus spanned the UACA gene, a key regulator of tumor suppressor Par-4. We found that receipt of chemotherapy modified the effect of the UACA locus on OS (Pinteraction = 2.4 x 10-4). This observation led us to hypothesize that the UACA locus effect on OS may be specific to Par-4 dependent chemotherapies, which include anti-HER2 therapy and doxorubicin. We stratified patients into two groups, those who received Par-4 dependent chemotherapy agents versus other patients. In separate trans-ethnic meta-GWAS, the UACA locus was significantly associated with OS in patients taking Par-4 dependent chemotherapies (P = 1.27 x 10-9), while no association was observed in the other patients (P = 0.21). To evaluate whether the UACA gene may be responsible for this association, we performed a transcriptome-wide association study (TWAS) of OS in White patients taking Par-4 dependent chemotherapies. Higher UACA gene expression was significantly associated with OS (P = 4.68 x 10-7), the only gene reaching transcriptome-wide significance (P &lt; 4.34 x 10-6). These results suggest that higher UACA expression may inhibit Par-4 induced apoptosis and lead to stronger chemoresistance and worse survival. We attempted to validate our findings in the independent KPNC Genetic Epidemiology Research on Aging (GERA) cohort. The GERA cohort included only 168 White patients with incident breast cancer after DNA collection who received Par-4 dependent chemotherapies. We found a non-significant association (hazard ratio (HR) = 1.46, P = 0.66) consistent with Pathways Study findings. However, the GERA cohort also included 1,983 prevalent breast cancer patients with biospecimen collection after diagnosis. In this group, the risk allele frequency in breast cancer survivors receiving Par-4 dependent chemotherapies was significantly lower than that in the White population (P = 5.50 x 10-3) while the risk allele frequency in the those not receiving these chemotherapies was similar to the population (P = 0.07). This is consistent with Pathways Study observations that the UACA locus risk allele significantly increased risk of mortality in patients taking Par-4 dependent chemotherapies. A higher mortality in breast cancer survivors carrying the risk allele would result in decreased risk allele frequency. We further validated our findings in Shanghai Breast Cancer Survival Study (SBCSS)and Shanghai Breast Cancer Study, which were conducted from 1996 to 2006 in urban Shanghai and recruited 5,575 breast cancer patients. In this independent Asian breast cancer population, the UACA locus was modestly associated with OS in the overall population (HR = 1.18, P = 0.012), and more significantly in 1,289 SBCSS patients who received anthracyclines (HR = 1.66, P = 1.55 x 10-4). This is the first human study suggesting the Par-4 pathway affects breast cancer patient survival with UACA a key modulator of treatment outcomes by anti-Her2 therapy and doxorubicin. Our findings suggest a path toward new predictive pharmacogenetic markers for personalized medicine targeting the Par-4 pathway for breast cancer treatment.

Citation Format: Lawrence H Kushi, Qianqian Zhu, Emily Schultz, Jirong Long, Janise M Roh, Emily Valice, Cecile A Laurent, Li Yan, Isaac J Ergas, Warren Davis, Dilrini K Ranatunga, Marilyn L Kwan, Ping-Ping Bao, Wei Zheng, Xiao-Ou Shu, Christine B Ambrosone, Song Yao. Genome-wide association study identifies UACA as a modulator of breast cancer chemoresistance and survival [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS2-05.

Association of FADS1/2 Locus Variants and Polyunsaturated Fatty Acids With Aortic Stenosis

Question

Can genetic analysis identify additional causes of aortic stenosis?

Findings

In this genome-wide association study of 44 703 participants, each copy of a FADS1/2 (fatty acid desaturase) genetic variant was associated with a 13% decrease in the odds of aortic stenosis. Results of a meta-analysis with 7 replication cohorts showed genome-wide significance, with biomarker and mendelian randomization analyses implicating elevated ω-6 fatty acid levels as having a potentially causal association with aortic valve calcium and aortic stenosis.

Meaning

These findings demonstrate that the FADS1/2 locus and fatty acid biosynthesis are associated with aortic stenosis and should be examined further for their potential as therapeutic targets.

Importance

Aortic stenosis (AS) has no approved medical treatment. Identifying etiological pathways for AS could identify pharmacological targets.

Objective

To identify novel genetic loci and pathways associated with AS.

Design, Setting, and Participants

This genome-wide association study used a case-control design to evaluate 44 703 participants (3469 cases of AS) of self-reported European ancestry from the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort (from January 1, 1996, to December 31, 2015). Replication was performed in 7 other cohorts totaling 256 926 participants (5926 cases of AS), with additional analyses performed in 6942 participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Follow-up biomarker analyses with aortic valve calcium (AVC) were also performed. Data were analyzed from May 1, 2017, to December 5, 2019.

Exposures

Genetic variants (615 643 variants) and polyunsaturated fatty acids (ω-6 and ω-3) measured in blood samples.

Main Outcomes and Measures

Aortic stenosis and aortic valve replacement defined by electronic health records, surgical records, or echocardiography and the presence of AVC measured by computed tomography.

Results

The mean (SD) age of the 44 703 GERA participants was 69.7 (8.4) years, and 22 019 (49.3%) were men. The rs174547 variant at the FADS1/2 locus was associated with AS (odds ratio [OR] per C allele, 0.88; 95% CI, 0.83-0.93; P = 3.0 × 10⁻⁶), with genome-wide significance after meta-analysis with 7 replication cohorts totaling 312 118 individuals (9395 cases of AS) (OR, 0.91; 95% CI, 0.88-0.94; P = 2.5 × 10⁻⁸). A consistent association with AVC was also observed (OR, 0.91; 95% CI, 0.83-0.99; P = .03). A higher ratio of arachidonic acid to linoleic acid was associated with AVC (OR per SD of the natural logarithm, 1.19; 95% CI, 1.09-1.30; P = 6.6 × 10⁻⁵). In mendelian randomization, increased FADS1 liver expression and arachidonic acid were associated with AS (OR per unit of normalized expression, 1.31 [95% CI, 1.17-1.48; P = 7.4 × 10⁻⁶]; OR per 5–percentage point increase in arachidonic acid for AVC, 1.23 [95% CI, 1.01-1.49; P = .04]; OR per 5–percentage point increase in arachidonic acid for AS, 1.08 [95% CI, 1.04-1.13; P = 4.1 × 10⁻⁴]).

Conclusions and Relevance

Variation at the FADS1/2 locus was associated with AS and AVC. Findings from biomarker measurements and mendelian randomization appear to link ω-6 fatty acid biosynthesis to AS, which may represent a therapeutic target.

Meta-Analysis of 26 638 Individuals Identifies Two Genetic Loci Associated With Left Ventricular Ejection Fraction

BACKGROUND

Left ventricular ejection fraction (EF) is an indicator of cardiac function, usually assessed in individuals with heart failure and other cardiac conditions. Although family studies indicate that EF has an important genetic component with heritability estimates up to 0.61, to date only 6 EF-associated loci have been reported.

METHODS

Here, we conducted a genome-wide association study (GWAS) of EF in 26 638 adults from the Genetic Epidemiology Research on Adult Health and Aging and the UK Biobank cohorts.

RESULTS

A meta-analysis combining results from Genetic Epidemiology Research on Adult Health and Aging and UK Biobank identified a novel locus: TMEM40 on chromosome 3p25 (rs11719526; β=0.47 and P=3.10×10^-8) that replicated in Biobank Japan and confirmed recent findings implicating the BAG3 locus on chromosome 10q26 in EF variation, with the strongest association observed for rs17617337 (β=-0.83 and P=8.24×10^-17). Although the minor allele frequencies of TMEM40 rs11719526 were generally common (between 0.13 and 0.44) in different ethnic groups, BAG3 rs17617337 was rare (minor allele frequencies<0.05) in Asian and African ancestry populations. These associations were slightly attenuated, after considering antecedent cardiac conditions (ie, heart failure/cardiomyopathy, hypertension, myocardial infarction, atrial fibrillation, valvular disease, and revascularization procedures). This suggests that the effects of the lead variants at TMEM40 or BAG3 on EF are largely independent of these conditions.

CONCLUSIONS

In this large and multiethnic study, we identified 2 loci, TMEM40 and BAG3, associated with EF at a genome-wide significance level. Identifying and understanding the genetic determinants of EF is important to better understand the pathophysiology of this strong correlate of cardiac outcomes and to help target the development of future therapies.

Associations of CYP2C9 and CYP2C19 Pharmacogenetic Variation with Phenytoin-Induced Cutaneous Adverse Drug Reactions

The role of cytochrome P450 (CYP)2C9 and CYP2C19 genetic variation in risk for phenytoin‐induced cutaneous adverse drug events is not well understood independently of the human leukocyte antigen B (HLA‐B)*15:02 risk allele. In the multi‐ethnic resource for Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort, we identified 382 participants who filled a phenytoin prescription between 2005 and 2017. These participants included 21 people (5%) who self‐identified as Asian, 18 (5%) as black, 29 (8%) as white Hispanic, and 308 (81%) as white non‐Hispanic. We identified 264 (69%) CYP2C9*1/*1, 77 (20%) CYP2C9*1/*2, and 29 (8%) CYP2C9*1/*3. We also determined CYP2C19 genotypes, including 112 with the increased activity CYP2C19*17 allele. Using electronic clinical notes, we identified 32 participants (8%) with phenytoin‐induced cutaneous adverse events recorded within 100 days of first phenytoin dispensing. Adjusting for age, sex, daily dose, and race/ethnicity, participants with CYP2C9*1/*3 or CYP2C9*2/*2 genotypes were more likely to develop cutaneous adverse events compared with CYP2C9*1/*1 participants (odds ratio 4.47; 95% confidence interval 1.64–11.69; P < 0.01). Among participants with low‐intermediate and poor CYP2C9 metabolizer genotypes, eight (22%) who also had extensive and rapid CYP2C19 metabolizer genotypes experienced cutaneous adverse events, compared with none of those who also had intermediate CYP2C19 metabolizer genotypes (P = 0.17). Genetic variation reducing CYP2C9 metabolic activity may increase risk for phenytoin‐induced cutaneous adverse events in the absence of the HLA‐B*15:02 risk allele.

Association of LPA Variants With Aortic Stenosis: A Large-Scale Study Using Diagnostic and Procedural Codes From Electronic Health Records

Importance

Elevated lipoprotein(a) levels are a risk factor for aortic stenosis (AS). However, a large-scale replication of associations between LPA variants and AS, their interactions with risk factors, and the effect of multiple risk alleles is not well established.

Objective

To replicate the association between LPA variants with AS and identify subgroups who are at higher risk of developing AS.

Design, Setting, and Participants

This case-control study of AS included 44 703 individuals (3469 cases) 55 years or older who were enrolled in the Genetic Epidemiology Research on Aging cohort and who were members of the Kaiser Permanente Northern California health care delivery system. The study leveraged the linkage of administrative health data, electronic medical records, genotypes, and self-reported questionnaire data. The 3469 AS cases were diagnosed between January 1996 and December 2015. Individuals with congential valvular heart disease were excluded.

Exposures

Two single-nucleotide polymorphisms in the LPA locus, rs10455872 and rs3798220, that are known to associate with circulating plasma lipoprotein(a) levels and an LPA risk score.

Main Outcomes and Measures

Aortic stenosis or aortic valve replacement.

Results

The 44 703 participants were of European ancestry,of whom 22 019 (49.3%) were men. The mean (SD) age for the control group was 69.3 (8.3) years and the mean (SD) age for AS cases was 74.6 (8.5) years. Both LPA variants were associated with AS, with a per risk allele odds ratio of 1.34 (95% CI, 1.23-1.47; P = 1.7 × 10-10) for rs10455872 and 1.31 (95% CI, 1.09-1.58; P = 3.6 × 10-3) for rs3798220 after adjusting for age, age2, and sex. The results remained significant after adjusting for risk factors. The estimates were similar for an LPA risk score. Individuals with 2 risk alleles had a 2-fold or greater odds of AS compared with individuals with no risk alleles (for rs10455872, homozygous odds ratio, 2.05; 95% CI, 1.37-3.07; P = 5.3 × 10-4; for rs3798220, homozygous odds ratio, 3.74; 95% CI, 1.03-13.62; P = .05; and for compound heterygotes, odds ratio, 2.00; 95% CI, 1.17-3.44; P = .01). For rs10455872, the odds ratio for AS was greatest in individuals aged 55 to 64 years and declined with age (interaction P = .03). Each rs10455872 risk allele was also associated with AS that was diagnosed 0.71 years earlier (95% CI, -1.42 to 0; P = .05).

Conclusions and Relevance

We provide a large-scale confirmation of the association between 2 LPA variants and AS, reaching genome-wide significance. In addition, individuals with 2 risk alleles have 2-fold or greater odds of developing AS. Age may modify these associations and identify subgroups who are at greater risk of developing AS.

A large electronic-health-record-based genome-wide study of serum lipids

A genome-wide association study of 94,674 multi-ethnic Kaiser Permanente members utilizing 478,866 longitudinal untreated serum lipid electronic-health-record-derived measurements (EHRs) empowered multiple novel findings: 121 new SNP associations (46 primary, 15 conditional, 60 in meta-analysis with Global Lipids Genetic Consortium); increase of 33-42% in variance explained with multiple measurements; sex differences in genetic impact (greater in females for LDL, HDL, TC, the opposite for TG); differences in variance explained amongst non-Hispanic whites, Latinos, African Americans, and East Asians; genetic dominance and epistasis, with strong evidence for both at ABOxFUT2 for LDL; and eQTL tissue-enrichment implicating the liver, adipose, and pancreas. Utilizing EHR pharmacy data, both LDL and TG genetic risk scores (477 SNPs) were strongly predictive of age-at-initiation of lipid-lowering treatment. These findings highlight the value of longitudinal EHRs for identifying novel genetic features of cholesterol and lipoprotein metabolism with implications for lipid treatment and risk of coronary heart disease.

Abstract 1297: Genetic reclassification of prostate-specific antigen levels for personalized prostate cancer screening

Background: Prostate-specific antigen (PSA) screening for prostate cancer results missed diagnoses as well as many unnecessary biopsies and their associated morbidities. Because PSA levels are heritable, traditional PSA screening may be improved by adjustment for constitutive germline genetics that influence PSA independently of prostate cancer.

Methods: In a previous genome-wide association study in non-Hispanic white men without prostate cancer in the Kaiser Permanente Research Program on Genes, Environment and Health cohort, we identified 40 single nucleotide polymorphisms (SNP) independently and significantly associated with PSA levels. Among them, 24 were not associated with prostate cancer risk. To calculate genetically normalized PSA (i.e., PSA’), we multiplied each man’s most recent PSA measurement by a factor that adjusted for the amount by which his 24 PSA-specific SNPs may have increased his PSA level. We then compared how men without prostate cancer were classified based on their PSA and PSA’ levels with regard to decisions for diagnostic testing.

Results: PSA and PSA’ were highly correlated among non-Hispanic white men without prostate cancer (r2: 0.959; 95% CI: 0.958-0.960). Still, 4.6% were reclassified from above to below a cutpoint of 2.5 ng/ml when using the PSA’ measure, and 2.7% were reclassified from below to above this cutpoint (4.6% - 2.7% = 1.9% net reclassified to below the cutoff). The reclassification was even more pronounced when restricting to controls with a negative prostate biopsy: 5.0% downward and 1.5% upward (3.5% net reclassified to below the cutoff).

Conclusions: Normalizing PSA levels using germline PSA variants may reduce the number of subjects without prostate cancer receiving unnecessary biopsies.

Citation Format: Rebecca E. Graff, Thomas J. Hoffmann, Michael N. Passarelli, Nima C. Emami, Lori C. Sakoda, Eric Jorgenson, Laurel A. Habel, Jun Shan, Dilrini K. Ranatunga, Charles P. Quesenberry, Chun R. Chao, Nirupa R. Ghai, David Aaronson, Joseph Presti, Tobias Nordström, Zhaoming Wang, Sonja I. Berndt, Stephen J. Chanock, Jonathan D. Mosley, Robert J. Klein, Mridu Middha, Hans Lilja, Olle Melander, Mark N. Kvale, Pui-Yan Kwok, Catherine Schaefer, Neil Risch, Neil Risch, Stephen K. Van Den Eeden, John S. Witte. Genetic reclassification of prostate-specific antigen levels for personalized prostate cancer screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1297. doi:10.1158/1538-7445.AM2017-1297

A large multiethnic genome-wide association study of prostate cancer identifies novel risk variants and substantial ethnic differences

A genome-wide association study (GWAS) of prostate cancer in Kaiser Permanente health plan members (7,783 cases, 38,595 controls; 80.3% non-Hispanic white, 4.9% African-American, 7.0% East Asian, and 7.8% Latino) revealed a new independent risk indel rs4646284 at the previously identified locus 6q25.3 that replicated in PEGASUS (N = 7,539) and the Multiethnic Cohort (N = 4,679) with an overall P = 1.0 × 10(-19) (OR, 1.18). Across the 6q25.3 locus, rs4646284 exhibited the strongest association with expression of SLC22A1 (P = 1.3 × 10(-23)) and SLC22A3 (P = 3.2 × 10(-52)). At the known 19q13.33 locus, rs2659124 (P = 1.3 × 10(-13); OR, 1.18) nominally replicated in PEGASUS. A risk score of 105 known risk SNPs was strongly associated with prostate cancer (P < 1.0 × 10(-8)). Comparing the highest to lowest risk score deciles, the OR was 6.22 for non-Hispanic whites, 5.82 for Latinos, 3.77 for African-Americans, and 3.38 for East Asians. In non-Hispanic whites, the 105 risk SNPs explained approximately 7.6% of disease heritability. The entire GWAS array explained approximately 33.4% of heritability, with a 4.3-fold enrichment within DNaseI hypersensitivity sites (P = 0.004).

SIGNIFICANCE

Taken together, our findings of independent risk variants, ethnic variation in existing SNP replication, and remaining unexplained heritability have important implications for further clarifying the genetic risk of prostate cancer. Our findings also suggest that there may be much promise in evaluating understudied variation, such as indels and ethnically diverse populations.

Clinical implications of the nelfinavir-proton pump inhibitor drug interaction in patients with human immunodeficiency virus

STUDY OBJECTIVE

To determine if the concomitant use of nelfinavir and proton pump inhibitors (PPIs) in patients with human immunodeficiency virus (HIV) infection results in the loss of virologic control.

DESIGN

Retrospective cohort study.

DATA SOURCE

Pharmacy, laboratory, and administrative databases of a large integrated health care system in northern California.

PATIENTS

A total of 1147 HIV-positive adults who started nelfinavir therapy between November 1, 1998, and June 20, 2003; within this cohort, 141 patients (12.3%) were also prescribed PPIs.

MEASUREMENTS AND MAIN RESULTS

The effects on two virologic outcomes--achievement of undetectable HIV viral load and subsequent virologic rebound--were compared between patients receiving nelfinavir alone and those receiving nelfinavir with PPIs. Cox proportional hazards models were used, with adjustments for age, sex, race, HIV risk factors, hepatitis B or C coinfection, and other concurrent drugs known to affect the metabolism of nelfinavir. The use of PPIs had little effect on the ability to achieve an undetectable HIV viral load (adjusted hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.58-1.19, p=0.29), but there was an approximate 50% increased risk of virologic rebound with the concurrent use of PPIs (adjusted HR 1.53, 95% CI 1.06-2.19, p=0.02). Short-term use of PPIs (defined as within 30 days of initial PPI dispensation) was not associated with increased risk of virologic rebound (HR 1.07, 95% CI 0.26-4.41, p=0.93) compared with no use of PPIs.

CONCLUSION

Use of PPIs should be minimized or avoided in patients who have attained an undetectable HIV viral load while taking a nelfinavir-based antiretroviral regimen. However, concomitant use of these drugs may be acceptable for indications where PPIs are required for fewer than 30 days.