Browsing by Author "Pardo Lameda, Ivanesa L."

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    Hyperammonemia and Ornithine Transcarbamylase Deficiency after Bariatric Surgery: A Retrospective Study
    Pardo Lameda, Ivanesa L.; Wang, Eugene; Sharbaugh, Matthew; Lovette, Anyea; Shope, Timothy R.; Koch, Timothy R. (Mary Ann Liebert, 2024-07-17)
    Background: The number of bariatric surgeries has risen in the past decades. Hyperammonemia related to ornithine transcarbamylase (OTC) deficiency is a potentially lethal disorder in patients with neurological symptoms. The apparent prevalence of OTC deficiency and potential predictors of mortality was examined in patients after bariatric surgery. Methods: This is a retrospective study of postoperative patients who developed hyperammonemia in a large, urban teaching hospital. Urinary orotic acid levels were ordered in individuals with elevated plasma ammonia. Results: Between January 2012 and August 2017, 1597 bariatric surgical procedures were performed. Seven women hospitalized with consistent symptoms had a mean peak plasma ammonia level of 155 umol/L (range: 57 to 273) and mean urinary orotic acid excretion of 3.3 mmol/mol creatinine (range: 1.6–7.9) after vertical sleeve gastrectomy, duodenal switch, or gastric bypass surgery, and there were four mortalities (57%). The apparent postoperative prevalence of OTC deficiency is 0.31%. Peak lactic acid (p = 0.011) level is a predictor of mortality. Conclusions: Hyperammonemia is associated with a high mortality rate predicted by high lactic acid levels. Postoperative prevalence of OTC deficiency is higher than the general population. Further investigations should examine potential mechanisms for its development.
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    Impact of Obesity Subtypes on Short-Term Weight Loss Following Vertical Sleeve Gastrectomy
    Shah, Raj A.; Nath, Anand; Shope, Timothy R.; Pardo Lameda, Ivanesa L.; Brebbia, John S.; Koch, Timothy R. (BP International, 2024-11-27)
    Background: Temporal prevalence studies of worldwide obesity have confirmed that this epidemic continues to worsen and investigators have suggested that the scope of this problem may indeed be underestimated. The pathogenesis of the condition is multifactorial and complex, and it has been suggested that early life exposure to environmental chemicals (termed obesogens) may be a major cause of this epidemic. Aims: Vertical sleeve gastrectomy has become the most common surgical intervention for medically-complicated obesity. This study was designed to examine the distribution of clinical subtypes of obesity (e.g. psychosocial factors, genetic risk, or obesogens) and to identify the best candidates for vertical sleeve gastrectomy based on clinical subtype. Study Design: This is a retrospective cohort study in a large, urban teaching hospital. Place and Duration of Study: Center for Advanced Laparoscopic & Bariatric Surgery, MedStar Washington Hospital Center Washington, DC between October 2018 and June 2019. Methodology: Consecutive new individuals (n=225) with medically-complicated obesity were evaluated preoperatively in an outpatient bariatric gastroenterology clinic. Subjects (n=17) were excluded. Eighty-four individuals underwent sleeve gastrectomy with a minimum of 6 months of postoperative follow up.
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    Obesity Subtypes and Short Term Weight Loss After Vertical Sleeve Gastrectomy: A Retrospective Cohort Study
    Shah, Raj A.; Nath, Anand; Shope, Timothy R.; Pardo Lameda, Ivanesa L.; Brebbia, John S.; Koch, Timothy R. (2022-12)
    AIM: Vertical sleeve gastrectomy has become the most common surgical intervention for medically-complicated obesity. This study examines the hypothesis that a clinical subtype of obesity (psychosocial factors, genetic risk, or early life endocrine disruptors termed obesogens) can identify the best candidates for vertical sleeve gastrectomy. MATERIALS AND METHODS: This is a retrospective cohort study of 225 consecutive new individuals with medically-complicated obesity seen preoperatively in outpatient bariatric clinic in an urban community teaching hospital. Eighty-four individuals underwent sleeve gastrectomy with a minimum of 6 months of follow up. RESULTS: Among 3 subtypes, early life obesogen exposure has been identified in 14.5% of individuals, genetic risk in 24.5% of individuals, and psychosocial factors in 61% of individuals. Percent excess weight loss (mean+/-SD) at 6 months is different among the three groups (pANOVA = 0.024). Individuals with genetic risk (38%+/-14) have significantly less weight loss (p = 0.029) than individuals with psychosocial factors (47%+/-15), while there is no difference compared to the obesogen subtype (41%+/-8.9). CONCLUSION: The most common clinical subtype of obesity is psychosocial factors, and there is significantly higher short term weight loss after sleeve gastrectomy in individuals with psychosocial factors. Weight loss may be limited by an individual’s genetic risk and early life obesogen exposure. A prospective study is required to confirm these findings.
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    Utility of the Non-Alcoholic Fatty Liver Disease Fibrosis Score in the Evaluation of Individuals with Medically-Complicated Obesity: A Retrospective Study
    Nath, Anand; Shope, Timothy R.; Pardo Lameda, Ivanesa L.; Koch, Timothy R. (Bentham Science Publishers, 2024-10-02)
    Background: Individuals with high body mass index (BMI) are at risk for chronic liver disease. Liver biopsy is a gold standard for the diagnosis of liver disease, as well as for determining the NAFLD activity score and fibrosis stage. Blood alanine aminotransferase (ALT) can support the presence of steatohepatitis, while the non-alcoholic fatty liver disease (NAFLD) fibrosis score (using clinical features and blood testing) may predict fibrosis. Based on prior studies, it is not clear whether the NAFLD fibrosis score is predictive of the NAFLD activity score or fibrosis stage. Aims: The aim was to examine whether clinical features and blood testing can identify the risk of chronic liver disease in those individuals with high BMI. Objective: Individuals with high BMI who may benefit from bariatric surgery were examined for the prevalence of steatohepatitis and for potential relationships between the NAFLD fibrosis score and the NAFLD activity score and fibrosis stage. Methods: This was a retrospective study of 593 consecutive individuals evaluated for bariatric surgery who underwent blood testing. Seventy individuals with a mean BMI of 49.9 kg/m2 underwent liver biopsy at surgery. Results: Elevated ALT was present in 102 subjects (17.2%). The correlation coefficient (R: 0.025; p = 0.83) between the NAFLD fibrosis score and NAFLD activity score was not significant, but there was a weak correlation between the NAFLD fibrosis score and fibrosis stage (R = 0.262; p = 0.28). Two individuals (3%) had cirrhosis. Conclusion: Elevated ALT may support the presence of liver disease in individuals with high BMI. There is a weak correlation between the NAFLD fibrosis score and the fibrosis stage. Further work is required to determine whether specific blood and clinical findings can be useful in making clinical decisions with regards to bariatric surgery in those individuals with high BMI.