Browsing by Author "Mahmud, Nadim"

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    A multiancestry genome-wide association study of unexplained chronic ALT elevation as a proxy for nonalcoholic fatty liver disease with histological and radiological validation
    (Springer Nature, 2022) Vujkovic, Marijana; Ramdas, Shweta; Lorenz, Kim M.; Guo, Xiuqing; Darlay, Rebecca; Cordell, Heather J.; He, Jing; Gindin, Yevgeniy; Chung, Chuhan; Myers, Robert P.; Schneider, Carolin V.; Park, Joseph; Lee, Kyung Min; Serper, Marina; Carr, Rotonya M.; Kaplan, David E.; Haas, Mary E.; MacLean, Matthew T.; Witschey, Walter R.; Zhu, Xiang; Tcheandjieu, Catherine; Kember, Rachel L.; Kranzler, Henry R.; Verma, Anurag; Giri, Ayush; Klarin, Derek M.; Sun, Yan V.; Huang, Jie; Huffman, Jennifer E.; Townsend Creasy, Kate; Hand, Nicholas J.; Liu, Ching-Ti; Long, Michelle T.; Yao, Jie; Budoff, Matthew; Tan, Jingyi; Li, Xiaohui; Lin, Henry J.; Chen, Yii-Der Ida; Taylor, Kent D.; Chang, Ruey-Kang; Krauss, Ronald M.; Vilarinho, Silvia; Brancale, Joseph; Nielsen, Jonas B.; Locke, Adam E.; Jones, Marcus B.; Verweij, Niek; Baras, Aris; Reddy, K. Rajender; Neuschwander-Tetri, Brent A.; Schwimmer, Jeffrey B.; Sanyal, Arun J.; Chalasani, Naga; Ryan, Kathleen A.; Mitchell, Braxton D.; Gill, Dipender; Wells, Andrew D.; Manduchi, Elisabetta; Saiman, Yedidya; Mahmud, Nadim; Miller, Donald R.; Reaven, Peter D.; Phillips, Lawrence S.; Muralidhar, Sumitra; DuVall, Scott L.; Lee, Jennifer S.; Assimes, Themistocles L.; Pyarajan, Saiju; Cho, Kelly; Edwards, Todd L.; Damrauer, Scott M.; Wilson, Peter W.; Gaziano, J. Michael; O'Donnell, Christopher J.; Khera, Amit V.; Grant, Struan F. A.; Brown, Christopher D.; Tsao, Philip S.; Saleheen, Danish; Lotta, Luca A.; Bastarache, Lisa; Anstee, Quentin M.; Daly, Ann K.; Meigs, James B.; Rotter, Jerome I.; Lynch, Julie A.; Regeneron Genetics Center; Geisinger-Regeneron DiscovEHR Collaboration; EPoS Consortium; VA Million Veteran Program; Rader, Daniel J.; Voight, Benjamin F.; Chang, Kyong-Mi; Medicine, School of Medicine
    Nonalcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease. Using a proxy NAFLD definition of chronic elevation of alanine aminotransferase (cALT) levels without other liver diseases, we performed a multiancestry genome-wide association study (GWAS) in the Million Veteran Program (MVP) including 90,408 cALT cases and 128,187 controls. Seventy-seven loci exceeded genome-wide significance, including 25 without prior NAFLD or alanine aminotransferase associations, with one additional locus identified in European American-only and two in African American-only analyses (P < 5 × 10-8). External replication in histology-defined NAFLD cohorts (7,397 cases and 56,785 controls) or radiologic imaging cohorts (n = 44,289) replicated 17 single-nucleotide polymorphisms (SNPs) (P < 6.5 × 10-4), of which 9 were new (TRIB1, PPARG, MTTP, SERPINA1, FTO, IL1RN, COBLL1, APOH and IFI30). Pleiotropy analysis showed that 61 of 77 multiancestry and all 17 replicated SNPs were jointly associated with metabolic and/or inflammatory traits, revealing a complex model of genetic architecture. Our approach integrating cALT, histology and imaging reveals new insights into genetic liability to NAFLD.
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    Performance of race-neutral eGFR equations in patients with decompensated cirrhosis
    (Wolters Kluwer, 2025) Fallahzadeh, Mohammad Amin; Allegretti, Andrew S.; Nadim, Mitra K.; Mahmud, Nadim; Patidar, Kavish R.; Cullaro, Giuseppe; Saracino, Giovanna; Asrani, Sumeet K.; Medicine, School of Medicine
    The 2021 Chronic Kidney Disease Epidemiology Collaboration equation [CKD-EPI 2021] is a race-neutral equation recently developed and rapidly implemented as a reference standard to estimate glomerular filtration rate(GFR). However, its role in cirrhosis has not been examined especially in low GFR. We analyzed the performance of CKD-EPI 2021 compared to other equations with protocol-measured GFR (mGFR) in cirrhosis. We analyzed 2090 unique adult patients with cirrhosis undergoing protocol GFR measurements using iothalamate clearance from 1985 to 2015 when listed for liver transplantation at Baylor University in Dallas and Fort Worth, Texas. Using mGFR as a reference standard, the CKD-EPI 2021 was compared to CKD-EPI 2012, Modification of Diet in Renal Disease-4, Modification of Diet in Renal Disease-6, Royal Free Hospital, and GFR Assessment in Liver disease overall and in certain subgroups (ascites, mGFR ≤ 30 mL/min/1.73 m 2 , diagnosis, Model for End-Stage Liver Disease and gender). We examined bias (difference between eGFR and mGFR), accuracy (p30: eGFR within ± 30% of mGFR) and agreement between eGFR and mGFR categories. CKD-EPI 2021 had the second lowest bias across the entire range of GFR after GFR Assessment in Liver disease (6.6 vs. 4.6 mL/min/1.73 m 2 , respectively, p < 0.001). The accuracy of CKD-EPI 2021 was similar to CKD-EPI 2012 (p30 = 67.8% vs. 67.9%, respectively) which was higher than the other equations ( p < 0.001). It had a similar performance in patients with ascites, by diagnoses, Model for End-Stage Liver Disease subgroups, by gender, and in non-Black patients. However, it had a relatively higher overestimation in mGFR ≤ 30 mL/min/1.73 m 2 than most equations (18.5 mL/min/1.73m 2 , p < 0.001). Specifically, 64% of patients with mGFR ≤ 30 mL/min/1.73m 2 were incorrectly classified as a less severe CKD stage by CKD-EPI 2021. In Blacks, CKD-EPI 2021 underestimated eGFR by 17.9 mL/min/1.73 m 2 , which was higher than the alternate equations except for Royal Free Hospital ( p < 0.001). The novel race-neutral eGFR equation, CKD-EPI 2021, improves the GFR estimation overall but may not accurately capture true kidney function in cirrhosis, specifically at low GFR. There is an urgent need for a race-neutral equation in liver disease reflecting the complexity of kidney function physiology unique to cirrhosis, given implications for organ allocation and dual organ transplant.
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    The impact of right atrial pressure on outcomes in patients undergoing TIPS, an ALTA group study
    (Wolters Kluwer, 2023) Bommena, Shoma; Mahmud, Nadim; Boike, Justin R.; Thornburg, Bartley G.; Kolli, Kanti P.; Lai, Jennifer C.; German, Margarita; Morelli, Giuseppe; Spengler, Erin; Said, Adnan; Desai, Archita P.; Junna, Shilpa; Paul, Sonali; Frenette, Catherine; Verna, Elizabeth C.; Goel, Aparna; Gregory, Dyanna; Padilla, Cynthia; VanWagner, Lisa B.; Fallon, Michael B.; Advancing Liver Therapeutic Approaches (ALTA) Study Group; Medicine, School of Medicine
    Background and aims: Single-center studies in patients undergoing TIPS suggest that elevated right atrial pressure (RAP) may influence survival. We assessed the impact of pre-TIPS RAP on outcomes using the Advancing Liver Therapeutic Approaches (ALTA) database. Approach and results: Total 883 patients in ALTA multicenter TIPS database from 2010 to 2015 from 9 centers with measured pre-TIPS RAP were included. Primary outcome was mortality. Secondary outcomes were 48-hour post-TIPS complications, post-TIPS portal hypertension complications, and post-TIPS inpatient admission for heart failure. Adjusted Cox Proportional hazards and competing risk model with liver transplant as a competing risk were used to assess RAP association with mortality. Restricted cubic splines were used to model nonlinear relationship. Logistic regression was used to assess RAP association with secondary outcomes.Pre-TIPS RAP was independently associated with overall mortality (subdistribution HR: 1.04 per mm Hg, 95% CI, 1.01, 1.08, p =0.009) and composite 48-hour complications. RAP was a predictor of TIPS dysfunction with increased odds of post-90-day paracentesis in outpatient TIPS, hospital admissions for renal dysfunction, and heart failure. Pre-TIPS RAP was positively associated with model for end-stage liver disease, body mass index, Native American and Black race, and lower platelets. Conclusions: Pre-TIPS RAP is an independent risk factor for overall mortality after TIPS insertion. Higher pre-TIPS RAP increased the odds of early complications and overall portal hypertensive complications as potential mechanisms for the mortality impact.