Person: Williams, Gordon
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Williams, Gordon
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Publication Patiromer induces rapid and sustained potassium lowering in patients with chronic kidney disease and hyperkalemia(Nature Publishing Group, 2015) Bushinsky, David A; Williams, Gordon; Pitt, Bertram; Weir, Matthew R; Freeman, Mason; Garza, Dahlia; Stasiv, Yuri; Li, Elizabeth; Berman, Lance; Bakris, George LPatients with chronic kidney disease (CKD) have a high risk of hyperkalemia, which increases mortality and can lead to renin–angiotensin–aldosterone system inhibitor (RAASi) dose reduction or discontinuation. Patiromer, a nonabsorbed potassium binder, has been shown to normalize serum potassium in patients with CKD and hyperkalemia on RAASi. Here, patiromer's onset of action was determined in patients with CKD and hyperkalemia taking at least one RAASi. After a 3-day potassium- and sodium-restricted diet in an inpatient research unit, those with sustained hyperkalemia (serum potassium 5.5 – under 6.5 mEq/l) received patiromer 8.4 g/dose with morning and evening meals for a total of four doses. Serum potassium was assessed at baseline (0 h), 4 h postdose, then every 2–4 h to 48 h, at 58 h, and during outpatient follow-up. Mean baseline serum potassium was 5.93 mEq/l and was significantly reduced by 7 h after the first dose and at all subsequent times through 48 h. Significantly, mean serum potassium under 5.5 mEq/l was achieved within 20 h. At 48 h (14 h after last dose), there was a significant mean reduction of 0.75 mEq/l. Serum potassium did not increase before the next dose or for 24 h after the last dose. Patiromer was well tolerated, without serious adverse events and no withdrawals. The most common gastrointestinal adverse event was mild constipation in two patients. No hypokalemia (serum potassium under 3.5 mEq/l) was observed. Thus, patiromer induced an early and sustained reduction in serum potassium and was well tolerated in patients with CKD and sustained hyperkalemia on RAASis.Publication HPA Axis Genetic Variation, Cortisol, and Psychosis in Major Depression(2013) Schatzberg, Alan F.; Keller, Jennifer; Tennakoon, Lakshika; Lembke, Anna; Williams, Gordon; Kraemer, Fredric B.; Sarginson, Jane E.; Lazzeroni, Laura C.; Murphy, Greer M.Genetic variation underlying hypothalamic pituitary adrenal (HPA) axis over-activity in healthy controls and patients with severe forms of major depression has not been well explored but could explain risk for cortisol dysregulation. 95 participants were studied: 40 patients with psychotic major depression (PMD); 26 patients with nonpsychotic major depression (NPMD); and 29 healthy controls (HC). Collection of genetic material was added one third of the way into a larger study on cortisol, cognition, and psychosis in major depression. Subjects were assessed using the Brief Psychiatric Rating Scale, the Hamilton Depression Rating Scale and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders. Blood was collected hourly for determination of cortisol from 6pm to 9am and for the assessment of alleles for 6 genes involved in HPA Axis regulation. Two of the 6 genes contributed significantly to cortisol levels, psychosis measures or depression severity. After accounting for age, depression, and psychosis, and medication status, only allelic variation for the glucocorticoid receptor gene (GR) accounted for significant variance for mean cortisol levels from 6pm to 1am (r2=.317) and from 1am to 9am (r2=.194). Interestingly, neither depression severity nor psychosis predicted cortisol variance. In addition, GR and corticotropin-releasing hormone receptor 1 (CRH-R1) contributed significantly to psychosis measures and CRH-R1 contributed significantly to depression severity rating.Publication Caveolin 1 Modulates Aldosterone‐Mediated Pathways of Glucose and Lipid Homeostasis(John Wiley and Sons Inc., 2016) Baudrand, Rene; Gupta, Nidhi; Garza, Amanda; Vaidya, Anand; Leopold, Jane; Hopkins, Paul N.; Jeunemaitre, Xavier; Ferri, Claudio; Romero, Jose; Williams, Jonathan; Loscalzo, Joseph; Adler, Gail; Williams, Gordon; Pojoga, LuminitaBackground: Overactivation of the aldosterone and mineralocorticoid receptor (MR) pathway is associated with hyperglycemia and dyslipidemia. Caveolin 1 (cav‐1) is involved in glucose/lipid homeostasis and may modulate MR signaling. We investigated the interplay between cav‐1 and aldosterone signaling in modulating insulin resistance and dyslipidemia in cav‐1–null mice and humans with a prevalent variant in the CAV1 gene. Methods and Results: In mouse studies, cav‐1 knockout mice exhibited higher levels of homeostatic model assessment of insulin resistance, cholesterol, and resistin and lower ratios of high‐ to low‐density lipoprotein (all P<0.001 versus wild type). Moreover, cav‐1 knockout mice displayed hypertriglyceridemia and higher mRNA levels for resistin, retinol binding protein 4, NADPH oxidase 4, and aldose reductase in liver and/or fat tissues. MR blockade with eplerenone significantly decreased glycemia (P<0.01), total cholesterol (P<0.05), resistin (P<0.05), and described enzymes, with no effect on insulin or triglycerides. In the human study, we analyzed the CAV1 gene polymorphism rs926198 in 556 white participants; 58% were minor allele carriers and displayed higher odds of insulin resistance (odds ratio 2.26 [95% CI 1.40–3.64]) and low high‐density lipoprotein (odds ratio 1.54 [95% CI 1.01–3.37]). Aldosterone levels correlated with higher homeostatic model assessment of insulin resistance and resistin and lower high‐density lipoprotein only in minor allele carriers. CAV1 gene expression quantitative trait loci data revealed lower cav‐1 expression in adipose tissues by the rs926198 minor allele. Conclusions: Our findings in mice and humans suggested that decreased cav‐1 expression may activate the effect of aldosterone/MR signaling on several pathways of glycemia, dyslipidemia, and resistin. In contrast, hyperinsulinemia and hypertriglyceridemia are likely mediated by MR‐independent mechanisms. Future human studies will elucidate the clinical relevance of MR blockade in patients with genotype‐mediated cav‐1 deficiency.Publication HPA Axis in Major Depression: Cortisol, Clinical Symptomatology, and Genetic Variation Predict Cognition(2016) Keller, Jennifer; Gomez, Rowena; Williams, Gordon; Lembke, Anna; Lazzeroni, Laura; Murphy, Greer M.; Schatzberg, Alan F.The Hypothalamic Pituitary Adrenal (HPA) axis has been implicated in the pathophysiology of a variety of mood and cognitive disorders. Neuroendocrine studies have demonstrated HPA axis overactivity in major depression, a relationship of HPA axis activity to cognitive performance, and a potential role of HPA axis genetic variation in cognition. The present study investigated the simultaneous roles HPA axis activity, clinical symptomatology, and HPA genetic variation play in cognitive performance. Patients with major depression with psychosis (PMD) and without psychosis (NPMD) and healthy controls (HC) were studied. All participants underwent a diagnostic interview and psychiatric ratings, a comprehensive neuropsychological battery, overnight hourly blood sampling for cortisol, and genetic assessment. Cognitive performance differed as a function of depression subtype. Across all subjects, cognitive performance was negatively correlated with higher cortisol, and PMD patients had higher cortisol than did NPMDs and HCs. Cortisol, clinical symptoms, and variation in genes, NR3C1 (glucocorticoid receptor - GR) and NR3C2 (minercorticoid receptor – MR) that encode for glucocorticoid and mineralcorticoid receptors, predicted cognitive performance. Beyond the effects of cortisol, demographics, and clinical symptoms, NR3C1 variation predicted attention and working memory, whereas NR3C2 polymorphisms predicted memory performance. These findings parallel the distribution of GR and MR in primate brain and their putative roles in specific cognitive tasks. HPA axis genetic variation and activity were important predictors of cognition across the entire sample of depressed subjects and healthy controls. GR and MR genetic variation predicted unique cognitive functions, beyond the influence of cortisol and clinical symptoms. GR genetic variation was implicated in attention and working memory, whereas MR was implicated in verbal memory.Publication No Interactions Between Previously Associated 2-Hour Glucose Gene Variants and Physical Activity or BMI on 2-Hour Glucose Levels(American Diabetes Association, 2012) Scott, Robert A.; Chu, Audrey Yu-lei; Grarup, Niels; Manning, Alisa K.; Hivert, Marie-France; Shungin, Dmitry; Tönjes, Anke; Yesupriya, Ajay; Barnes, Daniel; Bouatia-Naji, Nabila; Glazer, Nicole L.; Jackson, Anne U.; Kutalik, Zoltán; Lagou, Vasiliki; Marek, Diana; Rasmussen-Torvik, Laura J.; Stringham, Heather M.; Tanaka, Toshiko; Aadahl, Mette; Arking, Dan E.; Bergmann, Sven; Boerwinkle, Eric; Bonnycastle, Lori L.; Bornstein, Stefan R.; Brunner, Eric; Bumpstead, Suzannah J.; Brage, Soren; Carlson, Olga D.; Chen, Han; Chen, Yii-Der Ida; Chines, Peter S.; Collins, Francis S.; Couper, David J.; Dennison, Elaine M.; Dowling, Nicole F.; Egan, Josephine S.; Ekelund, Ulf; Erdos, Michael R.; Forouhi, Nita G.; Fox, Caroline; Goodarzi, Mark O.; Grässler, Jürgen; Gustafsson, Stefan; Hallmans, Göran; Hansen, Torben; Hingorani, Aroon; Holloway, John W.; Hu, Frank; Isomaa, Bo; Jameson, Karen A.; Johansson, Ingegerd; Jonsson, Anna; Jørgensen, Torben; Kivimaki, Mika; Kovacs, Peter; Kumari, Meena; Kuusisto, Johanna; Laakso, Markku; Lecoeur, Cécile; Lévy-Marchal, Claire; Li, Guo; Loos, Ruth J.F.; Lyssenko, Valeri; Marmot, Michael; Marques-Vidal, Pedro; Morken, Mario A.; Müller, Gabriele; North, Kari E.; Pankow, James S.; Payne, Felicity; Prokopenko, Inga; Psaty, Bruce M.; Renström, Frida; Rice, Ken; Rotter, Jerome I.; Rybin, Denis; Sandholt, Camilla H.; Sayer, Avan A.; Shrader, Peter; Schwarz, Peter E.H.; Siscovick, David S.; Stančáková, Alena; Stumvoll, Michael; Teslovich, Tanya M.; Waeber, Gérard; Williams, Gordon; Witte, Daniel R.; Wood, Andrew R.; Xie, Weijia; Boehnke, Michael; Cooper, Cyrus; Ferrucci, Luigi; Froguel, Philippe; Groop, Leif; Kao, W.H. Linda; Vollenweider, Peter; Walker, Mark; Watanabe, Richard M.; Pedersen, Oluf; Meigs, James; Ingelsson, Erik; Barroso, Inês; Florez, Jose; Franks, Paul W.; Dupuis, Josée; Wareham, Nicholas J.; Langenberg, ClaudiaGene–lifestyle interactions have been suggested to contribute to the development of type 2 diabetes. Glucose levels 2 h after a standard 75-g glucose challenge are used to diagnose diabetes and are associated with both genetic and lifestyle factors. However, whether these factors interact to determine 2-h glucose levels is unknown. We meta-analyzed single nucleotide polymorphism (SNP) × BMI and SNP × physical activity (PA) interaction regression models for five SNPs previously associated with 2-h glucose levels from up to 22 studies comprising 54,884 individuals without diabetes. PA levels were dichotomized, with individuals below the first quintile classified as inactive (20%) and the remainder as active (80%). BMI was considered a continuous trait. Inactive individuals had higher 2-h glucose levels than active individuals (β = 0.22 mmol/L [95% CI 0.13–0.31], P = 1.63 × 10−6). All SNPs were associated with 2-h glucose (β = 0.06–0.12 mmol/allele, P ≤ 1.53 × 10−7), but no significant interactions were found with PA (P > 0.18) or BMI (P ≥ 0.04). In this large study of gene–lifestyle interaction, we observed no interactions between genetic and lifestyle factors, both of which were associated with 2-h glucose. It is perhaps unlikely that top loci from genome-wide association studies will exhibit strong subgroup-specific effects, and may not, therefore, make the best candidates for the study of interactions.