Staging and clean room: Constructs designed to facilitate transparency and reduce bias in comparative analyses of real-world data.

PURPOSE: We describe constructs designed to protect the integrity of the results from comparative analyses using real-world data (RWD): staging and clean room. METHODS: Staging involves performing sequential preliminary analyses and evaluating the population size available and potential bias before conducting comparative analyses. A clean room involves restricted access to data and preliminary results, policies governing exploratory analyses and protocol deviations, and audit trail. These constructs are intended to allow decisions about protocol deviations, such as changes to design or model specification, to be made without knowledge of how they might affect subsequent analyses. We describe an example for implementing staging with a clean room. RESULTS: Stage 1 may involve selecting a data source, developing and registering a protocol, establishing a clean room, and applying inclusion/exclusion criteria. Stage 2 may involve attempting to achieve covariate balance, often through propensity score models. Stage 3 may involve evaluating the presence of residual confounding using negative control outcomes. After each stage, check points may be implemented when a team of statisticians, epidemiologists and clinicians masked to how their decisions may affect study outcomes, reviews the results. This review team may be tasked with making recommendations for protocol deviations to address study precision or bias. They may recommend proceeding to the next stage, conducting additional analyses to address bias, or terminating the study. Stage 4 may involve conducting the comparative analyses. CONCLUSIONS: The staging and clean room constructs are intended to protect the integrity and enhance confidence in the results of analyses of RWD.

Long-Term Levels of LDL-C and Cognitive Function: The CARDIA Study.

OBJECTIVES: It is uncertain if long-term levels of low-density lipoprotein-cholesterol (LDL-C) affect cognition in middle age. We examined the association of LDL-C levels over 25 years with cognitive function in a prospective cohort of black and white US adults. METHODS: Lipids were measured at baseline (1985-1986; age: 18-30 years) and at serial examinations conducted over 25 years. Time-averaged cumulative LDL-C was calculated using the area under the curve for 3,328 participants with ≥3 LDL-C measurements and a cognitive function assessment. Cognitive function was assessed at the Year 25 examination with the Digit Symbol Substitution Test [DSST], Rey Auditory Visual Learning Test [RAVLT], and Stroop Test. A brain magnetic resonance imaging (MRI) sub-study (N = 707) was also completed at Year 25 to assess abnormal white matter tissue volume (AWMV) and gray matter cerebral blood flow volume (GM-CBFV) as secondary outcomes. RESULTS: There were 15.6%, 32.9%, 28.9%, and 22.6% participants with time-averaged cumulative LDL-C <100 mg/dL, 101-129 mg/dL, 130-159 mg/dL, and ≥160 mg/dL, respectively. Standardized differences in all cognitive function test scores ranged from 0.16 SD lower to 0.09 SD higher across time-averaged LDL-C categories in comparison to those with LDL-C < 100 mg/dL. After covariate adjustment, participants with higher versus lower time-averaged LDL-C had a lower RAVLT score (p-trend = 0.02) but no differences were present for DSST, Stroop Test, AWMV, or GM-CBFV. CONCLUSION: Cumulative LDL-C was associated with small differences in memory, as assessed by RAVLT scores, but not other cognitive or brain MRI measures over 25 years of follow-up.

Trends in statin utilization among adults with severe peripheral artery disease including critical limb ischemia in an integrated healthcare delivery system.

Evidence suggests that statin therapy in patients with peripheral artery disease (PAD) is beneficial yet use remains suboptimal. We examined trends in statin use, intensity, and discontinuation among adults aged ⩾ 40 years with incident severe PAD and a subset with critical limb ischemia (CLI) between 2002 and 2015 within an integrated healthcare delivery system. Discontinuation of statin therapy was defined as the first 90-day gap in treatment within 1 year following PAD diagnosis. We identified 11,059 patients with incident severe PAD: 31.1% (n = 3442) with CLI and 68.9% (n = 7617) without CLI. Mean (SD) age was 68.6 (11.3) years, 60.5% were male, 54.2% white, 23.2% Hispanic, and 16.2% black. Statin use in the year before diagnosis increased from 50.4% in 2002 to 66.0% in 2015 (CLI: 43.7% to 68.0%; without CLI: 53.1% to 64.2%, respectively). The proportion of patients on high-intensity statins increased from 7.3% in 2002 to 41.9% in 2015 (CLI: 7.2% to 39.4%; without CLI: 7.4% to 44.2%, respectively). Of the 40.5% (n = 4481) who were not on a statin in the year before diagnosis, 13.5% (n = 607) newly initiated therapy within 1 month (CLI: 10.1% (n = 150); without CLI: 15.3% (n = 457)). Following diagnosis, 12.5% (n = 660) discontinued statin therapy within 1 year (CLI: 15.5% (n = 202); without CLI: 11.5% (n = 458)). Although use of statins increased from 2002 to 2015, a substantial proportion of the overall PAD and CLI subpopulation remained untreated with statins, representing a significant treatment gap in a population at high risk for cardiovascular events and adverse limb outcomes.

Excess Deaths Attributable to Influenza-Like Illness in the ESRD Population.

BACKGROUND: Morbidity and mortality vary seasonally. Timing and severity of influenza seasons contribute to those patterns, especially among vulnerable populations such as patients with ESRD. However, the extent to which influenza-like illness (ILI), a syndrome comprising a range of potentially serious respiratory tract infections, contributes to mortality in patients with ESRD has not been quantified. METHODS: We used data from the Centers for Disease Control and Prevention (CDC) Outpatient Influenza-like Illness Surveillance Network and Centers for Medicare and Medicaid Services ESRD death data from 2000 to 2013. After addressing the increasing trend in deaths due to the growing prevalent ESRD population, we calculated quarterly relative mortality compared with average third-quarter (summer) death counts. We used linear regression models to assess the relationship between ILI data and mortality, separately for quarters 4 and 1 for each influenza season, and model parameter estimates to predict seasonal mortality counts and calculate excess ILI-associated deaths. RESULTS: An estimated 1% absolute increase in quarterly ILI was associated with a 1.5% increase in relative mortality for quarter 4 and a 2.0% increase for quarter 1. The average number of annual deaths potentially attributable to ILI was substantial, about 1100 deaths per year. CONCLUSIONS: We found an association between community ILI activity and seasonal variation in all-cause mortality in patients with ESRD, with ILI likely contributing to >1000 deaths annually. Surveillance efforts, such as timely reporting to the CDC of ILI activity within dialysis units during influenza season, may help focus attention on high-risk periods for this vulnerable population.

PCSK9 loss-of-function variants and Lp(a) phenotypes among black US adults.

The pharmacologic inhibition of proprotein convertase subtilisin-kexin type 9 (PCSK9) lowers lipoprotein (a) [Lp(a)] concentrations. However, the impact of genetic PCSK9 loss-of-function variants (LOFVs) on Lp(a) is uncertain. We determined the association of PCSK9 LOFVs with Lp(a) measures among black adults. Genotyping for PCSK9 LOFVs was conducted in 10,196 black Reasons for Geographic and Racial Differences in Stroke study participants. Among 241 participants with and 723 randomly selected participants without PCSK9 LOFVs, Lp(a) concentations, apo(a) kringle IV (KIV) repeats (a proxy for isoform size), and oxidized phospholipid (OxPL) apoB levels were measured using validated methods. Median Lp(a) concentrations among participants with and without PCSK9 LOFVs were 63.2 and 80.4 nmol/l, respectively (P = 0.016). After adjusting for age, sex, estimated glomerular filtration rate, LDL cholesterol, and statin use, participants with versus without a PCSK9 LOFV had a lower median Lp(a) concentration [Δ = -18.8 nmol/l (95% CI: -34.2, -3.3)]. Median apo(a) isoform sizes were 24 and 23 KIV repeats (P = 0.12) among participants with and without PCSK9 LOFVs, respectively [Δ = 1.1 (95% CI: 0.2, 2.0) after adjustment]. Median OxPL-apoB levels among participants with and without PCSK9 LOFVs were 3.4 and 4.1 nM (P = 0.20), respectively [Δ = -1.2 nM (95% CI -2.4, -0.04) after adjustment]. Among black adults, PCSK9 LOFVs were associated with lower Lp(a) concentration and OxPL-apoB levels.

PCSK9 Variants, Low-Density Lipoprotein Cholesterol, and Neurocognitive Impairment: Reasons for Geographic and Racial Differences in Stroke Study (REGARDS).

BACKGROUND: Despite concerns about adverse neurocognitive events raised by prior trials, pharmacological PCSK9 (proprotein convertase subtilisin/kexin type-9) inhibition was not associated with neurocognitive effects in a recent phase 3 randomized trial. PCSK9 loss-of-function (LOF) variants that result in lifelong exposure to lower levels of low-density lipoprotein cholesterol can provide information on the potential long-term effects of lower low-density lipoprotein cholesterol on neurocognitive impairment and decline. METHODS: We investigated the association between PCSK9 LOF variants and neurocognitive impairment and decline among black REGARDS study (Reasons for Geographic and Racial Differences in Stroke) participants with (n=241) and without (n=10 454) C697X or Y142X LOF variants. Neurocognitive tests included the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) battery (Word List Learning, World List Delayed Recall, Semantic Animal Fluency) and Six-Item Screener (SIS) assessments, administered longitudinally during follow-up. Neurocognitive impairment was defined as a score ≥1.5 SD below age, sex, and education-based stratum-specific means on 2 or 3 CERAD assessments or, separately, a score <5 on any SIS assessment at baseline or during follow-up. Neurocognitive decline was assessed using standardized continuous scores on individual neurocognitive tests. RESULTS: The mean sample age was 64 years (SD, 9), 62% were women, and the prevalence of neurocognitive impairment at any assessment was 6.3% by CERAD and 15.4% by SIS definitions. Adjusted odds ratios for neurocognitive impairment for participants with versus without PCSK9 LOF variants were 1.11 (95% confidence interval [CI], 0.58-2.13) using the CERAD battery and 0.89 (95% CI, 0.61-1.30) using the SIS assessment. Standardized average differences in individual neurocognitive assessment scores over the 5.6-year (range, 0.1-9.1) study period ranged between 0.07 (95% CI, -0.06 to 0.20) and -0.07 (95% CI, -0.18 to 0.05) among participants with versus without PCSK9 LOF variants. Patterns of neurocognitive decline were similar between participants with and without PCSK9 LOF variants (all P>0.10). Odds ratios for neurocognitive impairment per 20 mg/dL low-density lipoprotein cholesterol decrements were 1.02 (95% CI, 0.96-1.08) and 0.99 (95% CI, 0.95-1.02) for the CERAD and SIS definitions of impairment, respectively. CONCLUSIONS: These results suggest that lifelong exposure to low PCSK9 levels and cumulative exposure to lower levels of low-density lipoprotein cholesterol are not associated with neurocognitive effects in blacks.

Characteristics and Cardiovascular Disease Event Rates among African Americans and Whites Who Meet the Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER) Trial Inclusion Criteria.

PURPOSE: Determine the risk for cardiovascular disease (CVD) events among adults with clinically evident CVD who meet the inclusion criteria for the FOURIER clinical trial on PCSK9 inhibition in a real-world database. METHODS: We analyzed data from 2072 African American and 2972 white REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants 45-85 years of age with clinically evident CVD. Study participants meeting the FOURIER inclusion criteria (one major or two minor cardiovascular risk factors, fasting LDL cholesterol ≥ 70 mg/dL or non-HDL cholesterol ≥ 100 mg/dL, triglycerides ≤ 400 mg/dL, and taking statin) were followed for CVD events (myocardial infarction, stroke, coronary revascularization, and CVD death) from baseline in 2003-2007 through 2014. RESULTS: Overall, 771 (37.2%) African Americans and 1200 (40.4%) whites met the FOURIER inclusion criteria. The CVD event rate per 1000 person years was 60.6 (95% CI 53.6-67.6) among African Americans and 63.5 (95% CI 57.7-69.3) among whites. The risk for CVD events among adults meeting the FOURIER inclusion criteria was higher for those with a history of multiple cardiovascular events (hazard ratios among African Americans and whites 1.34 [95% CI 1.05-1.71] and 1.34 [1.10-1.63], respectively), a prior coronary revascularization (1.44 [1.13-1.84] and 1.23 [1.00-1.52], respectively), diabetes (1.38 [1.08-1.76] and 1.41 [1.15-1.72], respectively), reduced glomerular filtration rate (1.63 [1.26-2.11] and 1.29 [1.03-1.62], respectively), and albuminuria (1.77 [1.37-2.27] and 1.33 [1.07-1.65], respectively). CONCLUSIONS: The CVD event rate is high among African Americans and whites meeting the FOURIER inclusion criteria. Characteristics associated with a higher CVD risk may inform the decision to initiate PCSK9 inhibition.

Medical Expenditures Among Medicare Beneficiaries with Statin-Associated Adverse Effects Following Myocardial Infarction.

PURPOSE: Compare medical expenditures among adults with statin-associated adverse effects (SAAE) and high statin adherence (HSA) following myocardial infarction (MI). METHODS: We analyzed expenditures in 2016 US dollars among Medicare beneficiaries with SAAE (n = 1741) and HSA (n = 55,567) who were ≥ 66 years of age and initiated moderate/high-intensity statins following an MI in 2007-2013. SAAE were identified through a claims-based algorithm, which included down-titrating statins and initiating ezetimibe, switching to ezetimibe monotherapy, having a rhabdomyolysis or antihyperlipidemic adverse event followed by statin down-titration or discontinuation, or switching between ≥ 3 statin types within 365 days following MI. HSA was defined by having a statin available to take for ≥ 80% of the days in the 365 days following MI. RESULTS: Expenditures among beneficiaries with SAAE and HSA were $40,776 (95% CI $38,329-$43,223) and $26,728 ($26,482-$26,974), respectively, in the 365 days following MI, and $34,238 ($31,396-$37,080) and $29,053 ($28,605-$29,500), respectively, for every year after the first 365 days. Multivariable-adjusted ratios comparing expenditures among beneficiaries with SAAE versus HSA in the first 365 days and after the first 365 days following MI were 1.51 (95% CI 1.43-1.59) and 1.23 (1.12-1.34), respectively. Inpatient and outpatient expenditures were higher among beneficiaries with SAAE versus HSA during and after the first 365 days following MI. Compared to beneficiaries with HSA, medication expenditures among those with SAAE were similar in the 365 days following MI, but higher afterwards. Other medical expenditures were higher among beneficiaries with SAAE versus HSA. CONCLUSION: SAAE are associated with increased expenditures following MI compared with HSA.

Titration to High-Intensity Statin Therapy Following Acute Myocardial Infarction in Patients With and Without Diabetes Mellitus.

BACKGROUND: Patients with diabetes mellitus (DM) have a high risk for cardiovascular disease (CVD) events after an acute myocardial infarction (AMI). High-intensity statins reduce CVD risk following AMI among patients with and without DM. METHODS: We determined the proportion of Medicare beneficiaries 66 to 75 years of age taking a low/moderate-intensity statin with (n = 6718) and without (n = 6414) DM who titrated to a high-intensity statin dosage (i.e., atorvastatin 40 or 80 mg, or rosuvastatin 20 or 40 mg) following an AMI hospitalization in 2014-2015. All patients had a pharmacy claim for a statin fill within 365 days prior to, and within 30 days after their AMI hospitalization. We excluded beneficiaries without Medicare fee-for-service coverage including pharmacy benefits during the study period and those with a pharmacy claim for a high-intensity statin prior to their AMI. RESULTS: The first statin fill following hospital discharge was for a high-intensity dosage among 37.7% and 44.4% of patients with and without DM, respectively. After multivariable adjustment, the risk ratio (RR) for titrating to a high-intensity statin comparing patients with versus without DM was 1.01 (95% CI 0.96, 1.06). Among patients whose first statin fill post-AMI was for a low/moderate-intensity dosage, 7.5% of those with DM titrated to a high-intensity statin within 182 days, compared with 9.2% of those without DM (multivariable-adjusted RR 0.90 [95% CI 0.75, 1.08]). CONCLUSIONS: Most patients taking a low/moderate-intensity statin were not titrated to a high-intensity dosage following AMI irrespective of their diabetes status, potentially leaving substantial residual risk for recurrent CVD events.

FTO genotype is associated with phenotypic variability of body mass index.

There is evidence across several species for genetic control of phenotypic variation of complex traits, such that the variance among phenotypes is genotype dependent. Understanding genetic control of variability is important in evolutionary biology, agricultural selection programmes and human medicine, yet for complex traits, no individual genetic variants associated with variance, as opposed to the mean, have been identified. Here we perform a meta-analysis of genome-wide association studies of phenotypic variation using ∼170,000 samples on height and body mass index (BMI) in human populations. We report evidence that the single nucleotide polymorphism (SNP) rs7202116 at the FTO gene locus, which is known to be associated with obesity (as measured by mean BMI for each rs7202116 genotype), is also associated with phenotypic variability. We show that the results are not due to scale effects or other artefacts, and find no other experiment-wise significant evidence for effects on variability, either at loci other than FTO for BMI or at any locus for height. The difference in variance for BMI among individuals with opposite homozygous genotypes at the FTO locus is approximately 7%, corresponding to a difference of ∼0.5 kilograms in the standard deviation of weight. Our results indicate that genetic variants can be discovered that are associated with variability, and that between-person variability in obesity can partly be explained by the genotype at the FTO locus. The results are consistent with reported FTO by environment interactions for BMI, possibly mediated by DNA methylation. Our BMI results for other SNPs and our height results for all SNPs suggest that most genetic variants, including those that influence mean height or mean BMI, are not associated with phenotypic variance, or that their effects on variability are too small to detect even with samples sizes greater than 100,000.

Development of algorithms for identifying fatal cardiovascular disease in Medicare claims.

BACKGROUND: Cause of death is often not available in administrative claims data. OBJECTIVE: To develop claims-based algorithms to identify deaths due to fatal cardiovascular disease (CVD; ie, fatal coronary heart disease [CHD] or stroke), CHD, and stroke. METHODS: Reasons for Geographic and Racial Differences in Stroke (REGARDS) study data were linked with Medicare claims to develop the algorithms. Events adjudicated by REGARDS study investigators were used as the gold standard. Stepwise selection was used to choose predictors from Medicare data for inclusion in the algorithms. C-index, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were used to assess algorithm performance. Net reclassification index (NRI) was used to compare the algorithms with an approach of classifying all deaths within 28 days following hospitalization for myocardial infarction and stroke to be fatal CVD. RESULTS: Data from 2,685 REGARDS participants with linkage to Medicare, who died between 2003 and 2013, were analyzed. The C-index for discriminating fatal CVD from other causes of death was 0.87. Using a cut-point that provided the closest observed-to-predicted number of fatal CVD events, the sensitivity was 0.64, specificity 0.90, PPV 0.65, and NPV 0.90. The algorithms resulted in positive NRIs compared with using deaths within 28 days following hospitalization for myocardial infarction and stroke. Claims-based algorithms for discriminating fatal CHD and fatal stroke performed similarly to fatal CVD. CONCLUSION: The claims-based algorithms developed to discriminate fatal CVD events from other causes of death performed better than the method of using hospital discharge diagnosis codes.

Primary Care Physician Perspectives on Barriers to Statin Treatment.

PURPOSE: Discontinuation of statin therapy represents a major challenge for effective cardiovascular disease prevention. It is unclear how often primary care physicians (PCPs) re-initiate statins and what barriers they encounter. We aimed to identify PCP perspectives on factors influencing statin re-initiation. METHODS: We conducted six nominal group discussions with 23 PCPs from the Deep South Continuing Medical Education network. PCPs answered questions about statin side effects, reasons their patients reported for discontinuing statins, how they respond when discontinuation is reported, and barriers they encounter in getting their patients to re-initiate statin therapy. Each group generated a list of responses in round-robin fashion. Then, each PCP independently ranked their top three responses to each question. For each PCP, the most important reason was given a weight of 3 votes, and the second and third most important reasons were given weights of 2 and 1, respectively. We categorized the individual responses into themes and determined the relative importance of each theme using a "percent of available votes" metric. RESULTS: PCPs reported that side effects, especially muscle/joint-related symptoms, were the most common reason patients reported for statin discontinuation (47% of available votes). PCPs reported statin re-challenge as their most common response when a patient discontinues statin use (31% of available votes). Patients' fear of side effects was ranked as the biggest challenge PCPs encounter in getting their patients to re-initiate statin therapy (70% of available votes). CONCLUSION: PCPs face challenges getting their patients to re-initiate statins, particularly after a patient reports side effects.

Epoetin Alfa and Outcomes in Dialysis amid Regulatory and Payment Reform.

Erythropoiesis-stimulating agents (ESAs) are commonly used to treat anemia in patients with CKD, including those receiving dialysis, although clinical trials have identified risks associated with ESA use. We evaluated the effects of changes in dialysis payment policies and product labeling instituted in 2011 on mortality and major cardiovascular events across the United States dialysis population in an open cohort study of patients on dialysis from January 1, 2005, through December 31, 2012, with Medicare as primary payer. We compared observed rates of death and major cardiovascular events in 2011 and 2012 with expected rates calculated on the basis of rates in 2005-2010, accounting for differences in patient characteristics and influenza virulence. An abrupt decline in erythropoietin dosing and hemoglobin concentration began in late 2010. Observed rates of all-cause mortality, cardiovascular mortality, and myocardial infarction in 2011 and 2012 were consistent with expected rates. During 2012, observed rates of stroke, venous thromboembolic disease (VTE), and heart failure were lower than expected (absolute deviation from trend per 100 patient-years [95% confidence interval]: -0.24 [-0.08 to -0.37] for stroke, -2.43 [-1.35 to -3.70] for VTE, and -0.77 [-0.28 to -1.27] for heart failure), although non-ESA-related changes in practice and Medicare payment penalties for rehospitalization may have confounded the results. This initial evidence suggests that action taken to mitigate risks associated with ESA use and changes in payment policy did not result in a relative increase in death or major cardiovascular events and may reflect improvements in stroke, VTE, and heart failure.

Whole-exome imputation of sequence variants identified two novel alleles associated with adult body height in African Americans.

Adult body height is a quantitative trait for which genome-wide association studies (GWAS) have identified numerous loci, primarily in European populations. These loci, comprising common variants, explain <10% of the phenotypic variance in height. We searched for novel associations between height and common (minor allele frequency, MAF ≥5%) or infrequent (0.5% < MAF < 5%) variants across the exome in African Americans. Using a reference panel of 1692 African Americans and 471 Europeans from the National Heart, Lung, and Blood Institute's (NHLBI) Exome Sequencing Project (ESP), we imputed whole-exome sequence data into 13 719 African Americans with existing array-based GWAS data (discovery). Variants achieving a height-association threshold of P < 5E-06 in the imputed dataset were followed up in an independent sample of 1989 African Americans with whole-exome sequence data (replication). We used P < 2.5E-07 (=0.05/196 779 variants) to define statistically significant associations in meta-analyses combining the discovery and replication sets (N = 15 708). We discovered and replicated three independent loci for association: 5p13.3/C5orf22/rs17410035 (MAF = 0.10, ß = 0.64 cm, P = 8.3E-08), 13q14.2/SPRYD7/rs114089985 (MAF = 0.03, ß = 1.46 cm, P = 4.8E-10) and 17q23.3/GH2/rs2006123 (MAF = 0.30; ß = 0.47 cm; P = 4.7E-09). Conditional analyses suggested 5p13.3 (C5orf22/rs17410035) and 13q14.2 (SPRYD7/rs114089985) may harbor novel height alleles independent of previous GWAS-identified variants (r(2) with GWAS loci <0.01); whereas 17q23.3/GH2/rs2006123 was correlated with GWAS-identified variants in European and African populations. Notably, 13q14.2/rs114089985 is infrequent in African Americans (MAF = 3%), extremely rare in European Americans (MAF = 0.03%), and monomorphic in Asian populations, suggesting it may be an African-American-specific height allele. Our findings demonstrate that whole-exome imputation of sequence variants can identify low-frequency variants and discover novel variants in non-European populations.

FTO genetic variants, dietary intake and body mass index: insights from 177,330 individuals.

FTO is the strongest known genetic susceptibility locus for obesity. Experimental studies in animals suggest the potential roles of FTO in regulating food intake. The interactive relation among FTO variants, dietary intake and body mass index (BMI) is complex and results from previous often small-scale studies in humans are highly inconsistent. We performed large-scale analyses based on data from 177,330 adults (154 439 Whites, 5776 African Americans and 17 115 Asians) from 40 studies to examine: (i) the association between the FTO-rs9939609 variant (or a proxy single-nucleotide polymorphism) and total energy and macronutrient intake and (ii) the interaction between the FTO variant and dietary intake on BMI. The minor allele (A-allele) of the FTO-rs9939609 variant was associated with higher BMI in Whites (effect per allele = 0.34 [0.31, 0.37] kg/m(2), P = 1.9 × 10(-105)), and all participants (0.30 [0.30, 0.35] kg/m(2), P = 3.6 × 10(-107)). The BMI-increasing allele of the FTO variant showed a significant association with higher dietary protein intake (effect per allele = 0.08 [0.06, 0.10] %, P = 2.4 × 10(-16)), and relative weak associations with lower total energy intake (-6.4 [-10.1, -2.6] kcal/day, P = 0.001) and lower dietary carbohydrate intake (-0.07 [-0.11, -0.02] %, P = 0.004). The associations with protein (P = 7.5 × 10(-9)) and total energy (P = 0.002) were attenuated but remained significant after adjustment for BMI. We did not find significant interactions between the FTO variant and dietary intake of total energy, protein, carbohydrate or fat on BMI. Our findings suggest a positive association between the BMI-increasing allele of FTO variant and higher dietary protein intake and offer insight into potential link between FTO, dietary protein intake and adiposity.

Gene-centric meta-analyses for central adiposity traits in up to 57 412 individuals of European descent confirm known loci and reveal several novel associations.

Waist circumference (WC) and waist-to-hip ratio (WHR) are surrogate measures of central adiposity that are associated with adverse cardiovascular events, type 2 diabetes and cancer independent of body mass index (BMI). WC and WHR are highly heritable with multiple susceptibility loci identified to date. We assessed the association between SNPs and BMI-adjusted WC and WHR and unadjusted WC in up to 57 412 individuals of European descent from 22 cohorts collaborating with the NHLBI's Candidate Gene Association Resource (CARe) project. The study population consisted of women and men aged 20-80 years. Study participants were genotyped using the ITMAT/Broad/CARE array, which includes ∼50 000 cosmopolitan tagged SNPs across ∼2100 cardiovascular-related genes. Each trait was modeled as a function of age, study site and principal components to control for population stratification, and we conducted a fixed-effects meta-analysis. No new loci for WC were observed. For WHR analyses, three novel loci were significantly associated (P < 2.4 × 10(-6)). Previously unreported rs2811337-G near TMCC1 was associated with increased WHR (ß ± SE, 0.048 ± 0.008, P = 7.7 × 10(-9)) as was rs7302703-G in HOXC10 (ß = 0.044 ± 0.008, P = 2.9 × 10(-7)) and rs936108-C in PEMT (ß = 0.035 ± 0.007, P = 1.9 × 10(-6)). Sex-stratified analyses revealed two additional novel signals among females only, rs12076073-A in SHC1 (ß = 0.10 ± 0.02, P = 1.9 × 10(-6)) and rs1037575-A in ATBDB4 (ß = 0.046 ± 0.01, P = 2.2 × 10(-6)), supporting an already established sexual dimorphism of central adiposity-related genetic variants. Functional analysis using ENCODE and eQTL databases revealed that several of these loci are in regulatory regions or regions with differential expression in adipose tissue.

Mapping adipose and muscle tissue expression quantitative trait loci in African Americans to identify genes for type 2 diabetes and obesity.

Relative to European Americans, type 2 diabetes (T2D) is more prevalent in African Americans (AAs). Genetic variation may modulate transcript abundance in insulin-responsive tissues and contribute to risk; yet, published studies identifying expression quantitative trait loci (eQTLs) in African ancestry populations are restricted to blood cells. This study aims to develop a map of genetically regulated transcripts expressed in tissues important for glucose homeostasis in AAs, critical for identifying the genetic etiology of T2D and related traits. Quantitative measures of adipose and muscle gene expression, and genotypic data were integrated in 260 non-diabetic AAs to identify expression regulatory variants. Their roles in genetic susceptibility to T2D, and related metabolic phenotypes, were evaluated by mining GWAS datasets. eQTL analysis identified 1971 and 2078 cis-eGenes in adipose and muscle, respectively. Cis-eQTLs for 885 transcripts including top cis-eGenes CHURC1, USMG5, and ERAP2 were identified in both tissues. 62.1 % of top cis-eSNPs were within ±50 kb of transcription start sites and cis-eGenes were enriched for mitochondrial transcripts. Mining GWAS databases revealed association of cis-eSNPs for more than 50 genes with T2D (e.g. PIK3C2A, RBMS1, UFSP1), gluco-metabolic phenotypes (e.g. INPP5E, SNX17, ERAP2, FN3KRP), and obesity (e.g. POMC, CPEB4). Integration of GWAS meta-analysis data from AA cohorts revealed the most significant association for cis-eSNPs of ATP5SL and MCCC1 genes, with T2D and BMI, respectively. This study developed the first comprehensive map of adipose and muscle tissue eQTLs in AAs (publically accessible at https://mdsetaa.phs.wakehealth.edu ) and identified genetically regulated transcripts for delineating genetic causes of T2D, and related metabolic phenotypes.

Effects of Epoetin Alfa Titration Practices, Implemented After Changes to Product Labeling, on Hemoglobin Levels, Transfusion Use, and Hospitalization Rates.

BACKGROUND: Little is known about epoetin alfa (EPO) dosing at dialysis centers after implementation of the US Medicare prospective payment system and revision of the EPO label in 2011. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Approximately 412,000 adult hemodialysis patients with Medicare Parts A and B as primary payer in 2009 to 2012 to describe EPO dosing and hemoglobin patterns; of these, about 70,000 patients clustered in about 1,300 dialysis facilities to evaluate facility-level EPO titration practices and patient-level outcomes in 2012. PREDICTOR: Facility EPO titration practices when hemoglobin levels were <10 and >11g/dL (grouped treatment variable) determined from monthly EPO dosing and hemoglobin level patterns. OUTCOMES: Patient mean hemoglobin levels, red blood cell transfusion rates, and all-cause and cause-specific hospitalization rates using a facility-based analysis. MEASUREMENTS: Monthly EPO dose and hemoglobin level, red blood cell transfusion rates, and all-cause and cause-specific hospitalization rates. RESULTS: Monthly EPO doses declined across all hemoglobin levels, with the greatest decline in patients with hemoglobin levels < 10g/dL (July-October 2011). In 2012, nine distinct facility titration practices were identified. Across groups, mean hemoglobin levels differed slightly (10.5-10.8g/dL) but within-patient hemoglobin standard deviations were similar (∼0.68g/dL). Patients at facilities implementing greater dose reductions and smaller dose escalations had lower hemoglobin levels and higher transfusion rates. In contrast, patients at facilities that implemented greater dose escalations (and large or small dose reductions) had higher hemoglobin levels and lower transfusion rates. There were no clinically meaningful differences in all-cause or cause-specific hospitalization events across groups. LIMITATIONS: Possibly incomplete claims data; excluded small facilities and those without consistent titration patterns; hemoglobin levels reported monthly; inferred facility practice from observed dosing. CONCLUSIONS: Following prospective payment system implementation and labeling revisions, EPO doses declined significantly. Under the new label, facility EPO titration practices were associated with mean hemoglobin levels (but not standard deviations) and transfusion use, but not hospitalization rates.

Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption.

Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits. We conducted a genome-wide (GW) meta-analysis of predominately regular-type coffee consumption (cups per day) among up to 91,462 coffee consumers of European ancestry with top single-nucleotide polymorphisms (SNPs) followed-up in ~30 062 and 7964 coffee consumers of European and African-American ancestry, respectively. Studies from both stages were combined in a trans-ethnic meta-analysis. Confirmed loci were examined for putative functional and biological relevance. Eight loci, including six novel loci, met GW significance (log10Bayes factor (BF)>5.64) with per-allele effect sizes of 0.03-0.14 cups per day. Six are located in or near genes potentially involved in pharmacokinetics (ABCG2, AHR, POR and CYP1A2) and pharmacodynamics (BDNF and SLC6A4) of caffeine. Two map to GCKR and MLXIPL genes related to metabolic traits but lacking known roles in coffee consumption. Enhancer and promoter histone marks populate the regions of many confirmed loci and several potential regulatory SNPs are highly correlated with the lead SNP of each. SNP alleles near GCKR, MLXIPL, BDNF and CYP1A2 that were associated with higher coffee consumption have previously been associated with smoking initiation, higher adiposity and fasting insulin and glucose but lower blood pressure and favorable lipid, inflammatory and liver enzyme profiles (P<5 × 10(-8)).Our genetic findings among European and African-American adults reinforce the role of caffeine in mediating habitual coffee consumption and may point to molecular mechanisms underlying inter-individual variability in pharmacological and health effects of coffee.

Algorithms to Identify Statin Intolerance in Medicare Administrative Claim Data.

PURPOSE: To compare characteristics of patients with possible statin intolerance identified using different claims-based algorithms versus patients with high adherence to statins. METHODS: We analyzed 134,863 Medicare beneficiaries initiating statins between 2007 and 2011. Statin intolerance and discontinuation, and high adherence to statins, defined by proportion of days covered ≥80 %, were assessed during the 365 days following statin initiation. Definition 1 of statin intolerance included statin down-titration or discontinuation with ezetimibe initiation, having a claim for a rhabdomyolysis or antihyperlipidemic event followed by statin down-titration or discontinuation, or switching between ≥3 types of statins. Definition 2 included beneficiaries who met Definition 1 and those who down-titrated statin intensity. We also analyzed beneficiaries who met Definition 2 of statin intolerance or discontinued statins. RESULTS: The prevalence of statin intolerance was 1.0 % (n = 1320) and 5.2 % (n = 6985) using Definitions 1 and 2, respectively. Overall, 45,266 (33.6 %) beneficiaries had statin intolerance by Definition 2 or discontinued statins and 55,990 (41.5 %) beneficiaries had high adherence to statins. Compared with beneficiaries with high adherence to statins, those with statin intolerance and who had statin intolerance or discontinued statins were more likely to be female versus male, and black, Hispanic or Asian versus white. The multivariable adjusted odds ratio for statin intolerance by Definitions 1 and 2 comparing patients initiating high versus low/moderate intensity statins were 2.82 (95%CI: 2.42-3.29), and 8.58 (8.07-9.12), respectively, and for statin intolerance or statin discontinuation was 2.35 (2.25-2.45). CONCLUSIONS: Definitions of statin intolerance presented herein can be applied to analyses using administrative claims data.