Katherine Yates - Academia.edu (original) (raw)

Papers by Katherine Yates

Neurogastroenterology and Motility, Mar 6, 2016

This study defined similarities and differences in gastroparesis severity, healthcare utilization... more This study defined similarities and differences in gastroparesis severity, healthcare utilization, psychological function, and quality of life in patients with type 1 (T1DM) and type 2 (T2DM) diabetes mellitus and gastroparesis. • At baseline enrollment into the NIDDK Gastroparesis Clinical Research Consortium Registry, T1DM patients had higher hemoglobin A1c (HbA1c) levels and more severe emptying delays, but the severity of GI symptoms was similar to those of patients with T2DM and gastroparesis. • After 48 weeks of follow-up in the Registry, gastroparesis symptom scores significantly decreased in T2DM patients but not in T1DM patients despite increased use of prokinetic, acid suppressant, anxiolytic, and gastric electrical stimulation therapy in the T1DM group. • Explanations for these differences in clinical outcomes at 48 weeks in patients with gastroparesis due to T1DM vs T2DM require further investigation.

Gastroenterology, May 1, 2013

Background. The management of patients with gastroparesis remains challenging in many ways includ... more Background. The management of patients with gastroparesis remains challenging in many ways including an inability to project the course of the disease in a given patient. In this study, our aim was to determine if how well statistical models can confidently predict symptomatic improvement after a year of standard of care medical treatment. Methods. We studied 358 patients with gastroparesis (including idiopathic as well as that associated with both type 1 and type 2 diabetes mellitus) enrolled in the NIDDK Gastroparesis Clinical Research Consortium (GpCRC) registry. We used logistic regression modeling to determine the degree to which initial characteristics predict symptomatic improvement after 48 weeks of standard of care medical treatment with visits at least every 16 weeks and prescribed medications or other therapies as per the judgment of the treating physician. Improvement was defined as a decline of at least 1 point in the GCSI scores at 48 weeks compared to the baseline score. Regression coefficients, 95% CIs, P-values and areas under the ROC were used to compare a comprehensive model with baseline characteristics such as symptom scores, demographics, lifestyle, gastric emptying, medical history and psychological quality of life (QOL) as predictors vs. a much smaller reduced model (derived using stepwise regression), using only baseline characteristics. Results. Both the comprehensive model and reduced models predicted improvement well (AUROCs .0.70) and there was no significant difference in predictive ability of the smaller model compared to the comprehensive model (P=0.11). See Table 1 for the coefficients, CIs, and P-values and the logistic equation used to predict improvement; see Figure 1 for the ROC comparisons. Conclusions: It is possible to construct a robust predictive equation that identifies patients with gastroparesis that are likely to improve after a year of follow-up, but better models are needed to more fully facilitate counseling of patients as well as top generate hypothesis for interventions to improve outcomes in future studies.

Gastroenterology, May 1, 2012

fullness (p<0.01), epigastric pain (p<0.01) and burning (p<0.01). Improvements in PedsQL and SMW ... more fullness (p<0.01), epigastric pain (p<0.01) and burning (p<0.01). Improvements in PedsQL and SMW total scores remained when analysis was limited to normal or delayed gastric emptying (p<0.05, p<0.05). Only 13% (3/24) needed tube feeds and 13% (3/24) parenteral nutrition after GES. School absences decreased from 57% to 31% of school days. Overall, 65% (13/20) reported their health was much improved after GES versus 15% (3/20) the same or worse. The majority (15/20) were satisfied with GES. Three were not satisfied due to lack of improvement, one developed back pain and another was later diagnosed with an eating disorder. Five reported complications. Four had discomfort or tenderness at the implantation site and another had a dead battery. Conclusions: In the largest series to date of pediatric patients who have undergone GES for GP and/or FD, we have found significant and sustained improvement not only in upper GI symptoms but also in quality of life and perception of global health. Patients were less dependent on tube feeding or parenteral nutrition and had fewer school absences. The majority is satisfied with the decision to place GES. Future studies are needed to assess for possible placebo effect and to evaluate predictors of outcome and long-term prognosis.

Gastroenterology, 2019

complications (retinopathy, nephropathy, peripheral neuropathy) in diabetic patients with symptom... more complications (retinopathy, nephropathy, peripheral neuropathy) in diabetic patients with symptoms of Gp; assessing if there are differences between T1DM and T2DM patients and between those with delayed or normal gastric emptying (GE). Methods: Diabetic patients with symptoms of Gp and negative endoscopy underwent history and physical examination, 4 hour GE scintigraphy, autonomic function testing, and questionnaires assessing symptoms (Patient Assessment of Upper GI Symptoms [PAGI-SYM] which includes Gastroparesis Cardinal Symptom Index [GCSI]). We enrolled diabetic patients with delayed or normal GE. Peripheral neuropathy was assessed by history and NTSS-6 questionnaire; nephropathy was assessed by history; retinopathy by history; autonomic dysfunction by history and autonomic function testing (ANSAR Medical Technologies; ANX 3.0). Results: 133 diabetic patients (59 T1DM and 74 T2DM; 103 delayed GE and 30 not delayed) with symptoms of Gp were studied. Duration of diabetes was greater in T1DM than T2DM (22 vs 16 years; p<0.001) and HgbA1c was greater in T1DM than T2DM (8.8 vs 8.0%; p=0.01). Presence of retinopathy (37 vs 24%; p=0.13), nephropathy (19 vs 11%; p=0.22), peripheral neuropathy (53 vs 39%; p=0.16) were not significantly different between T1DM and T2DM; although triopathies were seen in 10% of T1DM and 3% of T2DM (p=0.04). GCSI total score was greater in T1DM than T2DM (2.8 vs 2.4; p=0.04). Diabetics with delayed GE had increased bloating compared to diabetics with normal GE (3.0 vs 2.3; p=0.07). Diabetic patients with delayed GE had increased prevalence of retinopathy (36 vs 10%; p=0.006). The number of diabetic complications were greater in delayed GE than normal gastric emptying (1.0 vs 0.5; p=0.009). Increasing number of triopathies present was associated with increased gastric retention at 2 hours (p=0.005) and 4 hours (p=0.008). Using autonomic function testing, challenge parasympathetic excess, but not resting parasympathetic excess, was more prevalent in delayed GE (34 vs 10%; p=0.02), but not associated with number of triopathies or type of diabetic complication. Conclusions: This study demonstrates that in diabetic patients with symptoms of Gp, delayed GE was associated with presence of retinopathy and total number of diabetic complications. Although no differences were noted in the proportion of patients with diabetic complications, the number of triopathies was greater in T1DM vs T2DM. Presence of diabetic complications should raise awareness for pursuing Gp in either T1DM or T2DM.

Clinical Gastroenterology and Hepatology, 2021

BACKGROUND The use of domperidone (DOM), for gastroparesis (GP) remains controversial and limited... more BACKGROUND The use of domperidone (DOM), for gastroparesis (GP) remains controversial and limited. We aimed to present outcomes of DOM therapy for treatment of patients participating in the multicenter NIDDK Gastroparesis Clinical Research Consortium (GPCRC) Registries (GpR). METHODS The GpCRC cohort consisted of GP (75%) and GP-like symptoms patients but with normal gastric emptying (25%). The DOM group initiated therapy during the 96 weeks of enrollment in GpR1 and 2. Patients who had previously taken or were on DOM therapy at enrollment were excluded from this analysis. The control group did not use domperidone (non-DOM group) before or after enrollment. The following outcome measures were identified: change from baseline in Gastroparesis Cardinal Symptom Index (GCSI) total score, with 3 subscales, plus GERD and PAGI-QOL scores. RESULTS Overall, of 748 patients, 181 (24%) were in the DOM, while 567 were in non-DOM group. 63% of participants had idiopathic GP. At baseline DOM compared to non-DOM patients were significantly younger, had lower BMI, non-Hispanic ethnicity, a higher annual household income, lower narcotic utilization, lower supplemental and complimentary medication use, more likely to have delayed GET, as well as worse nausea and fullness scores. Compared to non-DOM, DOM patients experienced moderate, but significantly more improvement in GP outcome measures: GCSI total score (p=0.003), nausea (p=0.003), and fullness subscales (p=0.005), upper abdominal pain score (p=0.04), GERD score (p=0.05) and PAGI-QOL (p=0.05). CONCLUSIONS Utilizing the method of pragmatic modeling to evaluate long-term treatment of GP in a large GpCRC database, domperidone treatment resulted in moderately but significantly improved GP.

Gastroenterology, 2020

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) is the most common pediatric chronic ... more BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) is the most common pediatric chronic liver disease. Little is known about outcomes in recognized youth. METHODS: We compared paired liver biopsies from 122 of 139 children with NAFLD (74% male; 64% white; 71% Hispanic; mean age, 13 ± 3 years; age range, 8-17 years) who received placebo and standard of care lifestyle advice in 2 double-blind, randomized clinical trials within the nonalcoholic steatohepatitis (NASH) clinical research network from 2005 through 2015. We analyzed histologic changes with respect to baseline and longitudinal change in clinical variables using regression analysis. RESULTS: At enrollment, 31% of the children had definite NASH, 34% had borderline zone 1 NASH, 13% had borderline zone 3 NASH, and 21% had fatty liver but not NASH. Over a mean period of 1.6 ± 0.4 years, borderline or definite NASH resolved in 29% of the children, whereas 18% of the children with fatty liver or borderline NASH developed definite NASH. Fibrosis improved in 34% of the children but worsened in 23%. Any progression to definite NASH or in fibrosis occurred in 36% of the children, and both occurred in 11% of the children. Any improvement in NASH or fibrosis occurred in 52%, and both occurred in 20% of children. Type 2 diabetes developed in 5% of the cohort. Any progression to NASH and/or fibrosis was associated with adolescent age, higher waist circumference, levels of alanine or aspartate aminotransferase, total and low-density lipoprotein-cholesterol at baseline, increasing level of alanine aminotransferase, and hemoglobin A1C (P < .05). Progression to NASH and/or fibrosis were also associated with increasing level of gamma-glutamyl transferase and development of type 2 diabetes (P < .01). Increasing level of gamma-glutamyl transferase also associated with reduced odds of any improvement (P = .003). CONCLUSIONS: One-third of children with NAFLD enrolled in placebo groups of clinical trials had histologic features of progression within 2 years, in association with increasing obesity and serum levels of aminotransferases and loss of glucose homeostasis.

Gastroenterology, 2021

Background.The aim of this study was to clarify the pathophysiology of functional dyspepsia (FD),... more Background.The aim of this study was to clarify the pathophysiology of functional dyspepsia (FD), a highly prevalent gastrointestinal syndrome, and its relationship with the better understood syndrome of gastroparesis.Methods.Adult patients with chronic upper gastrointestinal symptoms were followed prospectively for 48 weeks in multi-center registry studies. Patients were classified as gastroparesis if gastric emptying was delayed; if not, they were labeled as FD if they met Rome III criteria. Study analysis was conducted using ANCOVA and regression models.Results.Of 944 patients enrolled over a 12-year period, 720 (76%) were in the gastroparesis group and 224 (24%) in the FD group. Baseline clinical characteristics and severity of upper gastrointestinal symptoms were highly similar. 48-week clinical outcome was also similar but at this time 42% of patients with an initial diagnosis of gastroparesis were reclassified as FD based on gastric emptying results at this time point, conversely, 37% of FD patients were reclassified as gastroparesis. Change in either direction was not associated with any difference in symptom severity changes. Full thickness biopsies of the stomach showed loss of interstitial cells of Cajal and CD206+ macrophages in both groups compared to obese controls.Conclusions.A year after initial classification, patients with FD and gastroparesis, as seen in tertiary referral centers at least, are not distinguishable by clinical and pathological features or by assessment of gastric emptying. Gastric emptying results are labile and do not reliably capture the pathophysiology of clinical symptoms in either condition. FD and gastroparesis are unified by characteristic pathological features and should be considered as part of the same spectrum of truly “organic” gastric neuromuscular disorders.ClinicalTrials.gov Identifier:{"type":"clinical-trial","attrs":{"text":"NCT00398801","term_id":"NCT00398801"}}NCT00398801, {"type":"clinical-trial","attrs":{"text":"NCT01696747","term_id":"NCT01696747"}}NCT01696747

Gastroenterology, 2018

Background: ERCP with biliary stent placement is currently the standard treatment for postsurgica... more Background: ERCP with biliary stent placement is currently the standard treatment for postsurgical bile leaks. However, the best method (ERCP or gastroscopy) and timing of stent removal is controversial. The Calgary Bile Leak Rule suggests that patients who present with bile leaks after a laparoscopic cholecystectomy, have a normal postsurgical ALP, and have a small or no leak with no other pathology identified on initial ERCP can safely have their stent removed via gastroscopy 4 to 8 weeks after stent insertion. Aims: We aimed to validate this prediction rule using the Ottawa Advanced Endoscopy Service experience. Methods: A retrospective chart review of patients who were endoscopically managed for surgical bile leaks between 2005 and 2017 at The Ottawa Hospital (TOH) were identified. The primary outcome was presence of persisting bile leak or other pathology on follow-up ERCP. Sensitivity, specificity, and the positive and negative predictive values were calculated for the Calgary Bile Leak Rule. Results: 71 cases met inclusion criteria and had sufficient data available to be considered for the validation analyses. 29 cases met most inclusion criteria but did not have sufficient data. 54 (76%) of bile leak cases had no leak identified during the followup ERCP and 17 (24%) had a persisting leak. The Calgary Bile Leak Rule demonstrated a sensitivity of 87% (95% CI, 75%-95%), a specificity of 6% (95% CI, 0%-29%), a positive predictive value of 75% (95% CI, 64%-85%), and a negative predictive value of 13% (95% CI, 2%-50%). Conclusions: The Calgary Bile Leak Rule demonstrated high sensitivity for predicting the need for repeat ERCPs after surgically induced bile leaks are treated with biliary stenting. Further evaluation using larger prospective data sources are needed prior to recommending this rule for clinical practice.

Digestive Diseases and Sciences, 2019

Background Marijuana may be used by some patients with gastroparesis (Gp) for its potential antie... more Background Marijuana may be used by some patients with gastroparesis (Gp) for its potential antiemetic, orexigenic, and pain-relieving effects. Aims The aim of this study was to describe the use of marijuana by patients for symptoms of Gp, assessing prevalence of use, patient characteristics, and patients' perceived benefit on their symptoms of Gp. Methods Patients with symptoms of Gp underwent history and physical examination, gastric emptying scintigraphy, and questionnaires assessing symptoms. Patients were asked about the current use of medications and alternative medications including marijuana. Results Fifty-nine of 506 (11.7%) patients with symptoms of Gp reported current marijuana use, being similar among patients with delayed and normal gastric emptying and similar in idiopathic and diabetic patients. Patients using marijuana were younger, more often current tobacco smokers, less likely to be a college graduate, married or have income > $50,000. Patients using marijuana had higher nausea/vomiting subscore (2.7 vs 2.1; p = 0.002), higher upper abdominal pain subscore (3.5 vs 2.9; p = 0.003), more likely to be using promethazine (37 vs 25%; p = 0.05) and dronabinol (17 vs 3%; p < 0.0001). Of patients using marijuana, 51% had been using it for more than 2 years, 47% were using this once or more per day, and 81% of marijuana users rated their benefit from marijuana as better or much better. Conclusions A subset of patients (12%) with symptoms of Gp use marijuana. Patients with severe nausea and abdominal pain were more likely to use marijuana and perceive it to be beneficial for their symptoms. Trial Registration ClinicalTrials.gov Identifier: NCT01696747.

Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, Jan 13, 2018

Many patients with gastroparesis are prescribed opioids for pain control, but indications for opi... more Many patients with gastroparesis are prescribed opioids for pain control, but indications for opioid prescription and relations of opioid use to gastroparesis manifestations are undefined. We characterized associations of use of potent vs weaker opioids and presentations of diabetic and idiopathic gastroparesis. We collected data on symptoms, gastric emptying, quality of life, and healthcare resource use from 583 patients with gastroparesis (more than 10% 4 hr scintigraphic retention) from the NIDDK Gastroparesis Consortium, from January 2007 through November 2016. Patients completed medical questionnaires that included questions about opioid use. The opioid(s) were categorized for potency relative to oral morphine. Symptom severities were quantified by Patient Assessment of Upper Gastrointestinal Disorders Symptoms questionnaires. Subgroup analyses compared patients on potent vs weaker opioids and opioid effects in diabetic vs idiopathic etiologies. Forty-one percent of patients we...

Gastroenterology, Dec 25, 2016

No treatment for nonalcoholic fatty liver disease (NAFLD) has been approved by regulatory agencie... more No treatment for nonalcoholic fatty liver disease (NAFLD) has been approved by regulatory agencies. We performed a randomized controlled trial to determine whether 52 weeks of cysteamine bitartrate delayed release (CBDR) reduces the severity of liver disease in children with NAFLD. We performed a double-masked trial of 169 children with NAFLD Activity Scores ≥ 4 at 10 centers. From June 2012 to January 2014, the patients were randomly assigned to receive CBDR or placebo twice daily (300 mg for ≤65 kg, 375 mg for >65-80 kg, 450 mg for >80 kg) for 52 weeks. The primary outcome from the intention to treat analysis was improvement in liver histology over 52 weeks, defined as a decrease in NAFLD Activity Score ≥ 2 points without worsening fibrosis; patients without biopsies from week 52 (17 in the CBDR group and 6 in the placebo group) were considered non-responders. We calculated relative risks (RR) of improvement using stratified Cochran-Mantel-Haenszel analysis. There was no sig...

Gastroenterology, 2016

EGG in all CKD patients (r=-0.620, P<0.001). 3) The HF (reflecting vagal activity) or LF/ HF (sym... more EGG in all CKD patients (r=-0.620, P<0.001). 3) The HF (reflecting vagal activity) or LF/ HF (sympathovagal ratio) in the spectrum of HRV showed no notable difference among the three groups. 4) The HD group exhibited a significantly higher plasma level of ghrelin (34.1±9.5mmol/L vs. 26.8±4.1mmol/L, P<0.05) and lower plasma level of GLP-1 (20.0±7.5pmol/L vs. 29.4±12.6 pmol/L, P < 0.05) in comparison with the CKD group. Moreover, there was a positive correlation between the percentage of normal slow waves in Channel 1 and the level of ghrelin (r=0.385, P=0.019) and a negative correlation (r=-0.558, P<0.001) between the percentage of normal slow waves in Channel 1 and the level of GLP-1 in all CKD patients. Conclusions: Hemodialysis improves GI symptoms and gastric slow waves in CKD patients. The improvement in gastric slow waves seems to be attributed to elevation of plasma level of ghrelin and suppression of plasma GLP-1 with hemodialysis.