Branched chain amino acids harbor distinct and often opposing effects on health and disease.

BACKGROUND: The branched chain amino acids (BCAA) leucine, isoleucine, and valine are essential nutrients that have been associated with diabetes, cancers, and cardiovascular diseases. Observational studies suggest that BCAAs exert homogeneous phenotypic effects, but these findings are inconsistent with results from experimental human and animal studies. METHODS: Hypothesizing that inconsistencies between observational and experimental BCAA studies reflect bias from shared lifestyle and genetic factors in observational studies, we used data from the UK Biobank and applied multivariable Mendelian randomization causal inference methods designed to address these biases. RESULTS: In n = 97,469 participants of European ancestry (mean age = 56.7 years; 54.1% female), we estimate distinct and often opposing total causal effects for each BCAA. For example, of the 117 phenotypes with evidence of a statistically significant total causal effect for at least one BCAA, almost half (44%, n = 52) are associated with only one BCAA. These 52 associations include total causal effects of valine on diabetic eye disease [odds ratio = 1.51, 95% confidence interval (CI) = 1.31, 1.76], valine on albuminuria (odds ratio = 1.14, 95% CI = 1.08, 1.20), and isoleucine on angina (odds ratio = 1.17, 95% CI = 1.31, 1.76). CONCLUSIONS: Our results suggest that the observational literature provides a flawed picture of BCAA phenotypic effects that is inconsistent with experimental studies and could mislead efforts developing novel therapeutics. More broadly, these findings motivate the development and application of causal inference approaches that enable 'omics studies conducted in observational settings to account for the biasing effects of shared genetic and lifestyle factors.

The three branched chain amino acids (BCAAs) leucine, isoleucine, and valine are important building blocks of muscle proteins that are obtained from the diet. Many studies in human populations have examined whether BCAAs affect health and disease. These human studies report results that are inconsistent with results from highly controlled animal studies. Because interest in the therapeutic targeting of BCAAs is growing, we wanted to better understand these discrepancies. Briefly, we used data from a large database that captured many diseases (e.g., cardiovascular disease, cancers, and respiratory disease) and new statistical methods. Our results showed that discrepancies between human studies and animal studies may reflect errors in the ways human studies were designed and conducted. As a result, these human studies may provide a flawed picture of BCAA effects that could mislead efforts developing novel therapeutics.

Ancestral diversity in lipoprotein(a) studies helps address evidence gaps.

INTRODUCTION: The independent and causal cardiovascular disease risk factor lipoprotein(a) (Lp(a)) is elevated in >1.5 billion individuals worldwide, but studies have prioritised European populations. METHODS: Here, we examined how ancestrally diverse studies could clarify Lp(a)'s genetic architecture, inform efforts examining application of Lp(a) polygenic risk scores (PRS), enable causal inference and identify unexpected Lp(a) phenotypic effects using data from African (n=25 208), East Asian (n=2895), European (n=362 558), South Asian (n=8192) and Hispanic/Latino (n=8946) populations. RESULTS: Fourteen genome-wide significant loci with numerous population specific signals of large effect were identified that enabled construction of Lp(a) PRS of moderate (R2=15% in East Asians) to high (R2=50% in Europeans) accuracy. For all populations, PRS showed promise as a 'rule out' for elevated Lp(a) because certainty of assignment to the low-risk threshold was high (88.0%-99.9%) across PRS thresholds (80th-99th percentile). Causal effects of increased Lp(a) with increased glycated haemoglobin were estimated for Europeans (p value =1.4×10-6), although inverse effects in Africans and East Asians suggested the potential for heterogeneous causal effects. Finally, Hispanic/Latinos were the only population in which known associations with coronary atherosclerosis and ischaemic heart disease were identified in external testing of Lp(a) PRS phenotypic effects. CONCLUSIONS: Our results emphasise the merits of prioritising ancestral diversity when addressing Lp(a) evidence gaps.

Strengthening Causal Inference in Exposomics Research: Application of Genetic Data and Methods.

Advances in technologies to measure a broad set of exposures have led to a range of exposome research efforts. Yet, these efforts have insufficiently integrated methods that incorporate genetic data to strengthen causal inference, despite evidence that many exposome-associated phenotypes are heritable. Objective: We demonstrate how integration of methods and study designs that incorporate genetic data can strengthen causal inference in exposomics research by helping address six challenges: reverse causation and unmeasured confounding, comprehensive examination of phenotypic effects, low efficiency, replication, multilevel data integration, and characterization of tissue-specific effects. Examples are drawn from studies of biomarkers and health behaviors, exposure domains where the causal inference methods we describe are most often applied. Discussion: Technological, computational, and statistical advances in genotyping, imputation, and analysis, combined with broad data sharing and cross-study collaborations, offer multiple opportunities to strengthen causal inference in exposomics research. Full application of these opportunities will require an expanded understanding of genetic variants that predict exposome phenotypes as well as an appreciation that the utility of genetic variants for causal inference will vary by exposure and may depend on large sample sizes. However, several of these challenges can be addressed through international scientific collaborations that prioritize data sharing. Ultimately, we anticipate that efforts to better integrate methods that incorporate genetic data will extend the reach of exposomics research by helping address the challenges of comprehensively measuring the exposome and its health effects across studies, the life course, and in varied contexts and diverse populations. https://doi.org/10.1289/EHP9098.

Risk of Hospitalization for Serious Infection After Initiation of Ustekinumab or Other Biologics in Patients With Psoriasis or Psoriatic Arthritis.

OBJECTIVE: To compare the risk of serious infections requiring hospitalization in patients with psoriasis (PsO) or psoriatic arthritis (PsA) initiating ustekinumab versus other biologics or apremilast. METHODS: In this multi-database cohort study, we identified patients with PsO/PsA who initiated therapy with adalimumab, apremilast, certolizumab, etanercept, golimumab, ixekizumab, secukinumab, or ustekinumab between 2009 and 2018. The primary outcome measure was hospitalizations due to serious infections, which included bacterial, viral, or opportunistic infections. We estimated hazard ratios (HRs) comparing each study drug to ustekinumab after applying propensity score fine stratification weights for confounding control in each database. Database-specific weighted HRs were combined by meta-analysis. RESULTS: We identified 123,383 patients with PsO/PsA who initiated one of the study drugs. During a total of 117,744 person-years of follow-up, 1,514 serious infections occurred with a crude incidence of 1.29 per 100 person-years. After propensity score fine stratification and weighting, the incidence rates of serious infection among ustekinumab initiators ranged from 0.59 to 0.95 per 100 person-years. Compared with ustekinumab, the combined weighted HRs (95% confidence interval [95% CI]) for serious infections were 1.66 (95% CI 1.34-2.06) for adalimumab, 1.42 (95% CI 1.02-1.96) for apremilast, 1.09 (95% CI 0.68-1.75) for certolizumab, 1.39 (95% CI 1.01-1.90) for etanercept, 1.74 (95% CI 1.00-3.03) for golimumab, 2.92 (95% CI 1.80-4.72) for infliximab, 2.98 (95% CI 1.20-7.41) for ixekizumab, and 1.84 (95% CI 1.24-2.72) for secukinumab. CONCLUSION: Other biologics and apremilast were associated with a 1.4- to 3-times higher risk of hospitalization for serious infections in PsO/PsA patients when compared to ustekinumab; this finding should be considered in the safety profile of these therapies when selecting appropriate treatment regimens in patients with PsO/PsA.

Analyses of biomarker traits in diverse UK biobank participants identify associations missed by European-centric analysis strategies.

Despite the dramatic underrepresentation of non-European populations in human genetics studies, researchers continue to exclude participants of non-European ancestry, as well as variants rare in European populations, even when these data are available. This practice perpetuates existing research disparities and can lead to important and large effect size associations being missed. Here, we conducted genome-wide association studies (GWAS) of 31 serum and urine biomarker quantitative traits in African (n = 9354), East Asian (n = 2559), and South Asian (n = 9823) ancestry UK Biobank (UKBB) participants. We adjusted for all known GWAS catalog variants for each trait, as well as novel signals identified in a recent European ancestry-focused analysis of UKBB participants. We identify 7 novel signals in African ancestry and 2 novel signals in South Asian ancestry participants (p < 1.61E-10). Many of these signals are highly plausible, including a cis pQTL for the gene encoding gamma-glutamyl transferase and PIEZO1 and G6PD variants with impacts on HbA1c through likely erythrocytic mechanisms. This work illustrates the importance of using the genetic data we already have in diverse populations, with novel discoveries possible in even modest sample sizes.

Risk Factors for Heart Failure with Preserved or Reduced Ejection Fraction Among Medicare Beneficiaries: Application of Competing Risks Analysis and Gradient Boosted Model.

BACKGROUND: The differential impact of various demographic characteristics and comorbid conditions on development of heart failure (HF) with preserved (pEF) and reduced ejection fraction (rEF) is not well studied among the elderly. METHODS: Using Medicare claims data linked to electronic health records, we conducted an observational cohort study of individuals ≥65 years of age without HF. A Cox proportional hazards model accounting for competing risk of HFrEF and HFpEF incidence was constructed. A gradient-boosted model (GBM) assessed the relative influence (RI) of each predictor in the development of HFrEF and HFpEF. RESULTS: Among 138,388 included individuals, 9701 developed HF (incidence rate = 20.9 per 1000 person-years). Males were more likely to develop HFrEF than HFpEF (HR = 2.07, 95% CI: 1.81-2.37 vs. 1.11, 95% CI: 1.02-1.20, P for heterogeneity <0.01). Atrial fibrillation and pulmonary hypertension had stronger associations with the risk of HFpEF (HR = 2.02, 95% CI: 1.80-2.26 and 1.66, 95% CI: 1.23-2.22) while cardiomyopathy and myocardial infarction were more strongly associated with HFrEF (HR = 4.37, 95% CI: 3.21-5.97 and 1.94, 95% CI: 1.23-3.07). Age was the strongest predictor across all HF subtypes with RI from GBM >35%. Atrial fibrillation was the most influential comorbidity for the development of HFpEF (RI = 8.4%) while cardiomyopathy was the most influential comorbidity for the development of HFrEF (RI = 20.7%). CONCLUSION: These findings of heterogeneous relationships between several important risk factors and heart failure types underline the potential differences in the etiology of HFpEF and HFrEF.

Risk of Serious Infection in Patients Receiving Systemic Medications for the Treatment of Psoriasis.

IMPORTANCE: There is a need for better understanding of the comparative safety of systemic medications used in the treatment of psoriasis. OBJECTIVE: To compare the risk of serious infection associated with biologic and nonbiologic systemic medications in patients with psoriasis. DESIGN, SETTING, AND PARTICIPANTS: An observational cohort study was conducted using medical and outpatient pharmacy claims from 2 large US health insurance claims databases from January 1, 2003, through September 30, 2015. We included patients with a diagnosis of psoriasis who were new users of systemic medications for psoriasis. EXPOSURES: Prescription claims for acitretin, adalimumab, apremilast, etanercept, infliximab, methotrexate, or ustekinumab. MAIN OUTCOMES AND MEASURES: The primary outcome was serious infection, defined by inpatient discharge diagnosis International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Cox proportional hazards regression was used to compare rates of serious infection for each exposure (acitretin, adalimumab, apremilast, etanercept, infliximab, and ustekinumab) with the referent group (methotrexate). We used pairwise 1:1 propensity score (PS) matching to adjust for potential confounders, which were assessed during a 180-day baseline period prior to study drug initiation. Results from the 2 databases were pooled via fixed-effects analysis. RESULTS: The databases included 31 595 patients in the Optum Clinformatics Data Mart and 76 112 patients in Truven MarketScan who were new users of acitretin, adalimumab, apremilast, etanercept, infliximab, methotrexate, and ustekinumab. Users of acitretin, apremilast, infliximab, and methotrexate were older and had higher baseline comorbidity scores than subcutaneous biologic users (adalimumab, etanercept, and ustekinumab). The pooled PS-matched analysis yielded a decreased rate of overall serious infection in users of apremilast (hazard ratio [HR], 0.50; 95% CI, 0.26-0.94), etanercept (HR, 0.75; 95% CI, 0.61-0.93), and ustekinumab (HR, 0.65; 95% CI, 0.47-0.89) compared with methotrexate. We did not find a different rate of overall serious infection among users of acitretin, adalimumab, and infliximab compared with methotrexate. Subanalysis by type of serious infection showed a significantly increased risk of cellulitis among users of acitretin compared with methotrexate (PS-adjusted HR, 1.76; 95% CI, 1.11-2.80). CONCLUSIONS AND RELEVANCE: Among patients with psoriasis treated with systemic medications in 2 large US claims databases, new users of apremilast, etanercept, and ustekinumab had a decreased rate of serious infection compared with methotrexate.

Association of Ustekinumab vs TNF Inhibitor Therapy With Risk of Atrial Fibrillation and Cardiovascular Events in Patients With Psoriasis or Psoriatic Arthritis.

Importance: Accumulating evidence indicates that there is an increased risk of cardiovascular disease among patients with psoriatic disease. Although an emerging concern that the risk of atrial fibrillation (AF) may also be higher in this patient population adds to the growing support of initiating early interventions to control systemic inflammation, evidence on the comparative cardiovascular safety of current biologic treatments remains limited. Objective: To evaluate the risk of AF and major adverse cardiovascular events (MACE) associated with use of ustekinumab vs tumor necrosis factor inhibitors (TNFi) in patients with psoriasis or psoriatic arthritis. Design, Setting, and Participants: This cohort study included data from a nationwide sample of 78 162 commercially insured patients in 2 US commercial insurance databases (Optum and MarketScan) from September 25, 2009, through September 30, 2015. Patients were included if they were 18 years or older, had psoriasis or psoriatic arthritis, and initiated ustekinumab or a TNFi therapy. Exclusion criteria included history of AF or receipt of antiarrhythmic or anticoagulant therapy during the baseline period. Exposures: Initiation of ustekinumab vs TNFi therapy. Main Outcomes and Measures: Incident AF and MACE, including myocardial infarction, stroke, or coronary revascularization. Results: A total of 60 028 patients with psoriasis or psoriatic arthritis (9071 ustekinumab initiators and 50 957 TNFi initiators) were included in the analyses. The mean (SD) age was 46 (13) years in Optum and 47 (13) in MarketScan, and 29 495 (49.1%) were male. Overall crude incidence rates (reported per 1000 person-years) for AF were 5.0 (95% CI, 3.8-6.5) for ustekinumab initiators and 4.7 (95% CI, 4.2-5.2) for TNFi initiators, and for MACE were 6.2 (95% CI, 4.9-7.8) for ustekinumab initiators and 6.1 (95% CI, 5.5-6.7) for TNFi initiators. The combined adjusted hazard ratio for incident AF among ustekinumab initiators was 1.08 (95% CI, 0.76-1.54) and for MACE among ustekinumab initiators was 1.10 (95% CI, 0.80-1.52) compared with TNFi initiators. Conclusions and Relevance: No substantially different risk of incident AF or MACE after initiation of ustekinumab vs TNFi was observed in this study. This information may be helpful when weighing the risks and benefits of various systemic treatment strategies for psoriatic disease.

Using Previous Medication Adherence to Predict Future Adherence.

BACKGROUND: Medication nonadherence is a major public health problem. Identification of patients who are likely to be and not be adherent can guide targeted interventions and improve the design of comparative-effectiveness studies. OBJECTIVE: To evaluate multiple measures of patient previous medication adherence in light of predicting future statin adherence in a large U.S. administrative claims database. METHODS: We identified a cohort of patients newly initiating statins and measured their previous adherence to other chronic preventive medications during a 365-day baseline period, using metrics such as proportion of days covered (PDC), lack of second fills, and number of dispensations. We measured adherence to statins during the year after initiation, defining high adherence as PDC ≥ 80%. We built logistic regression models from different combinations of baseline variables and previous adherence measures to predict high adherence in a random 50% sample and tested their discrimination using concordance statistics (c-statistics) in the other 50%. We also assessed the association between previous adherence and subsequent statin high adherence by fitting a modified Poisson model from all relevant covariates plus previous mean PDC categorized as < 25%, 25%-79%, and ≥ 80%. RESULTS: Among 89,490 statin initiators identified, a prediction model including only demographic variables had a c-statistic of 0.578 (95% CI = 0.573-0.584). A model combining information on patient comorbidities, health care services utilization, and medication use resulted in a c-statistic of 0.665 (95% CI = 0.659-0.670). Models with each of the previous medication adherence measures as the only explanatory variable yielded c-statistics ranging between 0.533 (95% CI = 0.529-0.537) for lack of second fill and 0.666 (95% CI = 0.661-0.671) for maximum PDC. Adding mean PDC to the combined model yielded a c-statistic of 0.695 (95% CI = 0.690-0.700). Given a sensitivity of 75%, the predictor improved the specificity from 47.7% to 53.6%. Patients with previous mean PDC < 25% were half as likely to show high adherence to statins compared with those with previous mean PDC ≥ 80% (risk ratio = 0.49, 95% CI = 0.46-0.50). CONCLUSIONS: Including measures of previous medication adherence yields better prediction of future statin adherence than usual baseline clinical measures that are typically used in claims-based studies. DISCLOSURES: This study was funded by the Patient-Centered Outcomes Research Institute (ME-1309-06274). Kumamaru, Kohsaka, and Miyata are affiliated with the Department of Healthcare Quality Assessment at the University of Tokyo, which is a social collaboration department supported by National Clinical Database. The department was formerly supported by endowments from Johnson & Johnson K.K., Nipro, Teijin Pharma, Kaketsuken K.K., St. Jude Medical Japan, Novartis Pharma K.K., Taiho Pharmaceutical, W. L. Gore & Associates, Olympus Corporation, and Chugai Pharmaceutical. Gagne has received grants from Novartis Pharmaceuticals and Eli Lilly and Company to the Brigham and Women's Hospital for unrelated work. He is a consultant to Aetion, a software company, and to Optum. Choudhry has received grants from the National Heart, Lung, and Blood Institute, PhRMA Foundation, Merck, Sanofi, AstraZeneca, CVS, and MediSafe. Schneeweiss is consultant to WHISCON and Aetion, a software manufacturer of which he also owns equity. He is principal investigator of investigator-initiated grants to the Brigham and Women's Hospital from Bayer, Genentech, and Boehringer Ingelheim unrelated to the topic of this study. He does not receive personal fees from biopharmaceutical companies. No potential conflict of interest was reported by the other authors.

Drug utilization patterns and adherence in patients on systemic medications for the treatment of psoriasis: A retrospective, comparative cohort study.

BACKGROUND: Nonadherence to systemic treatments for psoriasis leads to treatment failure and increased health care utilization. OBJECTIVE: Examine drug utilization patterns and adherence of new users of systemic medications for psoriasis. METHODS: We conducted a retrospective, comparative cohort study using a large US health insurance claims database including psoriasis patients who were new users of acitretin, adalimumab, etanercept, methotrexate, or ustekinumab. Adherence was measured by using proportion of days covered dichotomized as adherent (≥0.80) or nonadherent (<0.80). Odds ratios (ORs) and 95% confidence intervals (CIs) comparing adherence to each exposure (acitretin, adalimumab, etanercept, or ustekinumab) to the referent (methotrexate) were estimated via logistic regression, with pairwise 1:1 propensity score matching to adjust for potential confounders. RESULTS: In total, 22,742 patients were new users of systemic medications. Among these patients, adherence to adalimumab (OR 2.24, 95% CI 2.05-2.45); etanercept (OR 1.77, 95% CI 1.63-1.92); and ustekinumab (OR 2.54, 95% CI 2.24-2.87) was greater and acitretin (OR 0.57, 95% CI 0.50-0.63) lower compared with methotrexate. LIMITATIONS: Unable to evaluate reasons for discontinuation. CONCLUSION: We report greater adherence to biologics than methotrexate in new users. Further research is needed to understand overall low adherence to systemic medications for psoriasis.

Patterns of Systemic Treatment for Psoriatic Arthritis in the US: 2004-2015.

OBJECTIVE: To examine trends in the use of systemic disease-modifying antirheumatic drugs (DMARDs) among patients with psoriatic arthritis (PsA) in the US. METHODS: Using claims data (2004-2015) from a large US commercial health plan, we identified patients with PsA who initiated DMARD therapy. We examined baseline patient characteristics and initial treatment patterns. We then assessed changes in the DMARD regimen over the 12-month period after the first DMARD initiation date. Using Poisson regression, we estimated age- and sex-adjusted incidence rates of treatment changes in each calendar year. RESULTS: We identified 9,222 PsA patients who initiated DMARD therapy (42.8% biologic DMARDs [bDMARDs] and 57.2% conventional synthetic DMARDs [csDMARDs]). Initiators of bDMARDs were younger than those initiating csDMARDs (mean ± SD age 48 ± 13 versus 52 ± 14 years) and generally had fewer comorbidities, but a higher proportion of bDMARD initiators received nonsystemic treatments for psoriasis at baseline. Methotrexate was the most frequently used DMARD, constituting 80.6% of csDMARD initiations. Etanercept (49.1%) was the most commonly prescribed bDMARD, followed by adalimumab (34.4%). During the 12-month followup after the first DMARD initiation, 20.1% of bDMARD initiators and 31.1% of csDMARD initiators had their initial DMARD regimen modified, with an increasing trend in treatment modifications over the 11-year study period (P = 0.03). Overall, 5.3% of patients discontinued treatment, but the rates of discontinuation decreased over time (P < 0.001). CONCLUSION: In this large cohort of PsA patients with DMARD initiation, more than 40% were treated with a bDMARD. We found an increasing trend in treatment modification after use of the initial DMARD and a decreasing trend in complete DMARD discontinuation over the past decade.

Generic Versions of Narrow Therapeutic Index Drugs: A National Survey of Pharmacists' Substitution Beliefs and Practices.

Small changes in bioavailability of narrow therapeutic index (NTI) drugs can alter clinical outcomes, raising concern over generic NTI substitution. We surveyed pharmacists to identify their perceptions of generic NTI drugs, their frequency of performing generic NTI substitution, and predictors of this behavior. Of 710 respondents (33% response rate), 87% perceived generic NTI drugs as effective as their brand-name versions and 94% as safe. Whereas 82% almost always performed generic NTI substitution for initial prescriptions, only 60% did for refills. Pharmacists in non-chain settings (odds ratio (OR) = 2.37; 95% confidence interval (CI) = 1.40-4.02), in practice longer (per year OR = 1.04; 95% CI = 1.02-1.06), in states with affirmative patient consent laws (OR = 1.88; 95% CI = 1.06-3.32), and in states with NTI-specific substitution requirements (OR = 1.95; 95% CI = 1.16-3.26) were more likely not to substitute initial prescriptions. Education of non-chain and veteran pharmacists and elimination of affirmative patient consent and NTI-specific substitution requirements could increase generic NTI substitution.

Benzodiazepines and risk of all cause mortality in adults: cohort study.

Objectives To evaluate the risk of all cause mortality associated with initiating compared with not initiating benzodiazepines in adults, and to address potential treatment barriers and confounding related to the use of a non-active comparator group.Design Retrospective cohort study.Setting Large de-identified US commercial healthcare database (Optum Clinformatics Datamart).Participants 1:1 high dimensional propensity score matched cohort of benzodiazepine initiators, and randomly selected benzodiazepine non-initiators with a medical visit within 14 days of the start of benzodiazepine treatment (n=1 252 988), between July 2004 and December 2013. To address treatment barriers and confounding, patients were required to have filled one or more prescriptions for any medication in the 90 days and 91-180 days before the index date (ie, the date of starting benzodiazepine treatment for initiators and the date of the selected medical visit for benzodiazepine non-initiators) and the high dimensional propensity score was estimated on the basis of more than 300 covariates.Main outcome measure All cause mortality, determined by linkage with the Social Security Administration Death Master File.Results Over a six month follow-up period, 5061 and 4691 deaths occurred among high dimensional propensity score matched benzodiazepine initiators versus non-initiators (9.3 v 9.4 events per 1000 person years; hazard ratio 1.00, 95% confidence interval 0.96 to 1.04). A 4% (95% confidence interval 1% to 8%) to 9% (2% to 7%) increase in mortality risk was observed associated with the start of benzodiazepine treatment for follow-ups of 12 and 48 months and in subgroups of younger patients and patients initiating short acting agents. In secondary analyses comparing 1:1 high dimensional propensity score matched patients initiating benzodiazepines with an active comparator, ie, patients starting treatment with selective serotonin reuptake inhibitor antidepressants, benzodiazepine use was associated with a 9% (95% confidence interval 3% to 16%) increased risk.Conclusions This large population based cohort study suggests either no increase or at most a minor increase in risk of all cause mortality associated with benzodiazepine initiation. If a detrimental effect exists, it is likely to be much smaller than previously stated and to have uncertain clinical relevance. Residual confounding likely explains at least part of the small increase in mortality risk observed in selected analyses.

Fracture Risk After Bariatric Surgery: Roux-en-Y Gastric Bypass Versus Adjustable Gastric Banding.

The long-term consequences of bariatric surgery on fracture risk are unclear but are likely to vary by procedure type. In physiologic studies, Roux-en-Y gastric bypass (RYGB) and adjustable gastric banding (AGB) have differential effects on rates of bone loss. Therefore, our objective was to compare fracture risk in obese adults after RYGB and AGB procedures. Using claims data from a US commercial health plan, we analyzed rates of nonvertebral fractures within a propensity score-matched cohort (n = 15,032) of morbidly obese adults who received either RYGB or AGB surgery between 2005 and 2013. A total of 281 nonvertebral fractures occurred during a mean follow-up time of 2.3 ± 1.9 years. RYGB patients had an increased risk of nonvertebral fracture (hazard ratio [HR] = 1.43, 95% confidence interval [CI] 1.13-1.81) compared with AGB patients. In fracture site-specific analyses, RYGB patients had increased risk of fracture at the hip (HR = 1.54, 95% CI 1.03-2.30) and wrist (HR = 1.45, 95% CI 1.01-2.07). Nonvertebral fracture risk associated with RYGB manifested >2 years after surgery and increased in subsequent years, with the highest risk in the fifth year after surgery (HR = 3.91, 95% CI 1.58-9.64). In summary, RYGB is associated with a 43% increased risk of nonvertebral fracture compared with AGB, with risk increasing >2 years after surgery. Fracture risk should be considered in risk/benefit discussions of bariatric surgery, particularly among patients with high baseline risk of osteoporosis who are deciding between RYGB and AGB procedures. © 2017 American Society for Bone and Mineral Research.

Early Discontinuation of Metformin in Individuals Treated with Inhibitors of Transporters of Metformin.

The aim of this study was to examine the risk of early discontinuation of metformin as a proxy for intolerance, associated with use of drugs known to inhibit transporters involved in metformin distribution. We analysed all incident users of metformin in Denmark between 2000 and 2012 (n = 132,221) and in a cohort of US patients (n = 296,903). Risk of early discontinuation of metformin was assessed using adjusted logistic regression for 28 drugs putatively inhibiting metformin transporters and four negative controls. Increased odds ratio of early discontinuation of metformin was only associated with codeine, an inhibitor of organic cation transporter 1 in both cohorts [adjusted odds ratio (OR) in Danish cohort (95% CI): 1.13 (1.02-1.26), adjusted OR in American cohort (95% CI): 1.32 (1.19-1.47)]. The remaining drugs were not associated with increased odds ratio of early discontinuation and, surprisingly, four drugs were associated with a decreased risk. These findings indicate that codeine use may be associated with risk of early discontinuation of metformin and could be used as a basis for further investigation.