Circulating levels of gastrointestinal hormones in response to the most common types of bariatric surgery and predictive value for weight loss over one year: Evidence from two independent trials

AIMS

Bariatric surgery leads to profound and sustainable weight loss. Gastrointestinal hormones are involved in energy and glucose homeostasis, thus postoperative changes of their circulating levels may be mediating future weight loss. To investigate how the circulating concentrations of gastrointestinal hormones change in response to the most common types of bariatric operation and whether these changes can predict future weight loss.

MATERIALS AND METHODS

We measured circulating GLP-1, GLP-2, oxyntomodulin, glicentin, glucagon, major proglucagon fragment (MPGF), ghrelin, GIP, PYY after overnight fasting and/or after a mixed meal test (MMT) in: a) 14 subjects that have undergone either an adjustable gastric banding [AGB] (n = 9) or a Roux-en-Y bypass (RYGB) (n = 5) (Pilot study 1), b) 28 subjects that have undergone either a vertical sleeve gastrectomy (n = 17) or a RYGB (n = 11) before and three, six and twelve months after surgery.

RESULTS

In addition to the expected associations with GLP-1, the most robust increases were observed in postprandial levels of oxyntomodulin and glicentin three months after VSG or RYGB (but not after AGB) and are associated with degree of weight loss. Oxyntomodulin and glicentin levels at the third and sixth month postoperative visit are positively associated with feeling of satiety which may be underlying the observed associations with future weight loss.

CONCLUSION

Beyond GLP-1, early postprandial changes in circulating oxyntomodulin and glicentin are predictors of weight loss after bariatric surgery, possibly through regulation of satiety. Further studies should focus on underlying mechanisms, and their potential as attractive therapeutic tools against obesity and related comorbidities.

When can a second conservative approach be considered for ipsilateral breast tumour recurrence?

BACKGROUND

Mastectomy is considered the treatment of choice in patients with ipsilateral breast tumour recurrence (IBTR) after breast-conserving surgery (BCS).

PATIENTS AND METHODS

One hundred and sixty-one patients with invasive IBTR who underwent a second conservative approach were retrospectively evaluated in order to describe prognosis, determine predictive factors of outcome and select the subset of patients with the best local control.

RESULTS

Fifty-seven patients (35.4%) relapsed after IBTR. Thirty-four patients (21.1%) had further in-breast recurrences and four patients (2.5%) had skin relapses. Five years cumulative incidence of local relapse was 31.4%. Twenty-four patients (17.8%, 5 years cumulative incidence) died during the follow-up. At the multivariate analysis, recurrent tumour size >2 cm was found to affect local-disease-free survival [hazard ratio (HR): 2.8, 95% confidence interval (CI) 1.2-6.2], whereas Ki-67 >or=20% and time to relapse <or=48 months were associated with disease-free survival (HR: 1.7, 95% CI 1.0-3.1, and HR: 2.1, 95% CI 1.2-3.6, respectively). Absence of oestrogen receptors affected overall survival (HR: 2.5, 95% CI 1.1-6.0). Among 64 patients with recurrent tumour <or=2 cm and time to IBTR >48 months, eight (12.8%, 5 years cumulative incidence) had further local relapses.

CONCLUSIONS

Some patients with IBTR might receive a second BCS, especially when a good local control can be estimated (small recurrent tumour, late relapse), also taking into account patients' preference.

Follistatins in glucose regulation in healthy and obese individuals

AIMS

It has been suggested recently that follistatin (FST) and its homologous protein, follistatin-like 3 (FSTL3), may be a therapeutic target in the treatment of type 2 diabetes because of their glucose-regulatory effects in rodents.

MATERIALS AND METHODS

We investigated this hypothesis in humans by studying the physiology of a possible glycaemia-follistatin feedback loop, that is, whether glucose, but not lipid intake (oral or intravenous), can regulate circulating FST and FSTL3 in healthy humans (n = 32), whether the levels of follistatins change in response to various types of bariatric operation in morbidly obese individuals, with or without type 2 diabetes (n = 41), and whether such changes are associated prospectively with improvement of glucose homeostasis/insulin sensitivity.

RESULTS

In healthy individuals, circulating FST decreases after intravenous or oral glucose intake compared to controls, indicating the presence of a negative feedback mechanism. In morbid obesity, insulin resistance, glycaemia, circulating FST and FSTL3 are all reduced (by 22%-33%) after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy. Importantly, the changes in circulating FST 3 months after bariatric surgery are associated prospectively with the changes in glucose, insulin, HOMA-IR and HbA1c observed 6 months postoperatively in individuals with and without type 2 diabetes.

CONCLUSIONS

Our findings provide evidence of an important role of FST in glucose homeostasis in healthy individuals as well as in severely obese individuals with insulin resistance and type 2 diabetes. Our data extend recent results from animal studies to humans and support the need for further evaluation of FST inactivation strategies for targeting hyperglycaemia and insulin resistance.

Physiology of Activins/Follistatins: Associations With Metabolic and Anthropometric Variables and Response to Exercise

CONTEXT

Clinical trials are evaluating the efficacy of inhibitors of the myostatin pathway in neuromuscular and metabolic diseases. Activins and follistatins are major regulators of the myostatin pathway, but their physiology in relation to metabolic and anthropometric variables and in response to exercise remains to be fully elucidated in humans.

OBJECTIVE

We investigated whether concentrations of circulating activin A, activin B, follistatin, and follistatin-like 3 (FSTL3) are associated with anthropometric and metabolic variables and whether they are affected by exercise.

DESIGN

Activin A, activin B, follistatin, and FSTL3 were measured in (1) 80 subjects divided according to age (young vs old) and fitness status (active vs sedentary) before and after exercise at 70% maximal oxygen consumption (VO2max), followed by 90% of VO2max until exhaustion; and (2) 23 subjects [9 healthy and 14 with metabolic syndrome (MetS)] who completed four sessions: no exercise, high-intensity interval exercise, continuous moderate-intensity exercise, and resistance exercise for up to 45 minutes.

RESULTS

At baseline, follistatin and FSTL3 concentrations were positively associated with age, fat percentage, and body mass index (P < 0.001). Follistatin was positively associated with serum cholesterol (P = 0.005), low-density lipoprotein cholesterol (P = 0.01), triglycerides (P = 0.033), and blood pressure (P = 0.019), whereas activin A and activin B were higher in physically active participants (P = 0.056 and 0.029, respectively). All exercise types increased the levels of all hormones ∼10% to 21% (P = 0.034 for activin B, P < 0.001 for the others) independent of the presence of MetS.

CONCLUSION

Concentrations of circulating activins and follistatins are associated with metabolic parameters and increase after 45 minutes of exercise.

Unavoidable mastectomy for ipsilateral breast tumour recurrence after conservative surgery: patient outcome

BACKGROUND

In the case of ipsilateral breast tumour recurrence (IBTR) after breast-conserving surgery (BCS), a second conservative surgical approach maybe considered in some motivated patients whereas in others mastectomy is unavoidable.

PATIENTS AND METHODS

From 1997 to 2004, 282 patients presented at the European Institute of Oncology with an operable invasive IBTR after BCS. One hundred and sixty-one (57%) underwent a second conservative surgery, whereas 121 patients (43%) were given a mastectomy and represent the study population. We investigated the prognosis and determined predictive factors of outcome.

RESULTS

Median time from primary breast cancer to IBTR was 41 months (range 5-213). Recurrences were T2-T4 and/or multifocal in 83 cases (68.6%). With a median follow-up of 5 years after mastectomy, 5-year overall survival (OS) and disease-free survival (DFS) were 73.3% [95% confidence interval (CI) 65.0% to 81.6%] and 50.4% (95% CI 40.9% to 59.8%), respectively. At the multivariate analysis, early onset of IBTR, presence of vascular invasion and Ki67 >or=20 of the recurrent tumour were found to significantly affect both DFS and OS.

CONCLUSIONS

In women who need mastectomy for IBTR, early onset of the relapse, high proliferation index and presence of vascular invasion represent the worst prognostic factors.

Mesenchymal stem cell (MSC)-mediated survival of insulin producing pancreatic β-cells during cellular stress involves signalling via Akt and ERK1/2

Mesenchymal stem cells (MSC) are of interest for cell therapy since their secreted factors mediate immunomodulation and support tissue regeneration. This study investigated the direct humoral interactions between MSC and pancreatic β-cells using human telomerase-immortalized MSC (hMSC-TERT) and rat insulinoma-derived INS-1E β-cells. hMSC-TERT supported survival of cocultured INS-1E β-cells during cellular stress by alloxan (ALX) and streptozotocin (STZ), but not in response to IL-1β. Accordingly, hMSC-TERT had no effect on inflammatory cytokine-related signalling via NF-kB and p-JNK but maintained p-Akt and upregulated p-ERK1/2. Inhibition of either p-Akt or p-ERK1/2 did not abolish protection by hMSC-TERT but activated the respective non-inhibited pathway. This suggests that one pathway compensates for the other. Main results were confirmed in mouse islets except hMSC-TERT-mediated upregulation of p-ERK1/2. Therefore, MSC promote β-cell survival by preservation of p-Akt signalling and further involve p-ERK1/2 activation in certain conditions such as loss of p-Akt or insulinoma background.

Is avoiding post-mastectomy radiotherapy justified for patients with four or more involved axillary nodes and endocrine-responsive tumours? Lessons from a series in a single institution

BACKGROUND

Current guidelines for post-mastectomy radiotherapy (PMRT) derive largely from extrapolating information from multicentre trials. The aim of this study was to describe outcomes of patients who underwent mastectomy without radiotherapy in a single institution.

PATIENTS AND METHODS

650 patients had total mastectomy and axillary dissection without PMRT between 1997 and 2001. Median follow-up was 65 months.

RESULTS

5-year cumulative incidence of loco-regional recurrence (LRR) was 6.8% (3.0, 8.1, 9.9% in node negative, 1-3, > or =4 positive nodes, respectively). At the multivariate analysis, positive lymph nodes and endocrine non-responsive tumours were found to shorten LRR disease-free survival. In patients with positive hormone receptors, 5-year cumulative incidence of LRR disease-free survival were 2.3%, 7.6% and 7.6% for node negative, 1-3 and > or =4 positive lymph nodes, respectively. The same figures were 5.9%, 10.3% and 20.0% in patients with endocrine non-responsive tumours.

CONCLUSIONS

patients with endocrine-responsive tumours treated by mastectomy and complete (level III) axillary dissection have a low risk of LRR even if four or more positive lymph nodes are involved, thus giving rise to doubts on the use of PMRT in this subset of patients. On the other hand, PMRT might play a role for patients with negative hormone receptors and four or more positive nodes.

Circulating levels of the components of the GH/IGF-1/IGFBPs axis total and intact IGF-binding proteins (IGFBP) 3 and IGFBP 4 and total IGFBP 5, as well as PAPPA, PAPPA2 and Stanniocalcin-2 levels are not altered in response to energy deprivation and/or metreleptin administration in humans

OBJECTIVE

It remains unclear whether food deprivation induces changes in components of the GH/IGF-1/IGFBPs axis and if yes, which ones are mediated by leptin, an adipocyte secreted hormone regulating neuroendocrine response to energy deprivation in animals and humans. We aimed to investigate components of the axis that have not been studied to date, i.e. IGF-binding proteins (IGFBPs) and related proteases (total and intact IGFBP 3 and IGFBP 4, total IGFBP 5, PAPPA, PAPPA2 and Stanniocalcin-2), during acute (short-term fasting in healthy subjects) and chronic (women with hypothalamic amenorrhea [HA] due to excessive exercise) energy deprivation and whether metreleptin administration, in replacement, supraphysiologic or pharmacologic levels, may mediate any changes of circulating levels of the above molecules in healthy individuals and in women with hypothalamic amenorrhea.

METHODS

We studied: 1) 11 healthy men and women during three four day admissions i.e. a baseline admission in the fed isocaloric state and two admissions in the complete food deprivation state for 72-h with either placebo (resulting in a hypoleptinemic state) or metreleptin administration in doses designed to normalize circulating leptin levels for the duration of the study, 2) 15 healthy men and women during three 72-hour long admissions in a complete food deprivation state receiving three escalating doses of metreleptin designed to bring circulating leptin levels to physiologic, supraphysiologic, or pharmacologic levels, and 3) 18 women with HA randomized to either metreleptin treatment in replacement doses or placebo for nine months.

RESULTS

There were no significant changes in the circulating profiles of the above molecules in the fasting vs. fed state and/or with metreleptin administration during acute and chronic energy deprivation.

CONCLUSIONS

The studied components of the GH/IGF-1/IGFBPs axis are not affected by energy deprivation, leptin deficiency associated with energy deprivation, or by metreleptin administration in physiologic, supraphysiologic or pharmacologic doses.

Metabolic regulation of activins in healthy individuals and in obese patients undergoing bariatric surgery

OBJECTIVE

Follistatin binds and inactivates activins, which are potent inhibitors of muscle growth and metabolism and are currently being developed for the treatment of obesity and type 2 diabetes (T2D). We have recently reported that follistatin is regulated by glucose (and not lipids) and can prospectively predict the metabolic improvements observed after bariatric surgery. We utilized novel assays herein to investigate whether activins are regulated by glucose or lipids, whether their circulating levels change after bariatric surgery and whether these changes are predictors of metabolic outcomes up to 12 months later.

DESIGN AND METHODS

Activin A, B, AB and their ratios to follistatin were measured in (a) healthy humans (n = 32) undergoing oral or intravenous lipid or glucose intake over 6 h, (b) morbidly obese individuals with or without type 2 diabetes undergoing three different types of bariatric surgery (gastric banding, Roux-en-Y bypass or sleeve gastrectomy) in two clinical studies (n = 14 for the first and n = 27 for the second study).

RESULTS

Glucose intake downregulates circulating activin A, B and AB, indicating the presence of a feedback loop. Activin A decreases (~30%), activin AB increases (~25%) and activin B does not change after bariatric surgery. The changes in activin AB and its ratio to follistatin 3 months after bariatric surgery can predict the BMI reduction and the improvement in insulin and HOMA-IR observed 6 months postoperatively.

CONCLUSION

Activins are implicated in glucose regulation in humans as part of a feedback loop with glucose or insulin and predict metabolic outcomes prospectively after bariatric surgery.

The Selective Peroxisome Proliferator-Activated Receptor Gamma Modulator CHS-131 Improves Liver Histopathology and Metabolism in a Mouse Model of Obesity and Nonalcoholic Steatohepatitis

CHS-131 is a selective peroxisome proliferator-activated receptor gamma modulator with antidiabetic effects and less fluid retention and weight gain compared to thiazolidinediones in phase II clinical trials. We investigated the effects of CHS-131 on metabolic parameters and liver histopathology in a diet-induced obese (DIO) and biopsy-confirmed mouse model of nonalcoholic steatohepatitis (NASH). Male C57BL/6JRj mice were fed the amylin liver NASH diet (40% fat with trans-fat, 20% fructose, and 2% cholesterol). After 36 weeks, only animals with biopsy-confirmed steatosis and fibrosis were included and stratified into treatment groups (n = 12-13) to receive for the next 12 weeks (1) low-dose CHS-131 (10 mg/kg), (2) high-dose CHS-131 (30 mg/kg), or (3) vehicle. Metabolic parameters, liver pathology, metabolomics/lipidomics, markers of liver function and liver, and subcutaneous and visceral adipose tissue gene expression profiles were assessed. CHS-131 did not affect body weight, fat mass, lean mass, water mass, or food intake in DIO-NASH mice with fibrosis. CHS-131 improved fasting insulin levels and insulin sensitivity as assessed by the intraperitoneal insulin tolerance test. CHS-131 improved total plasma cholesterol, triglycerides, alanine aminotransferase, and aspartate aminotransferase and increased plasma adiponectin levels. CHS-131 (high dose) improved liver histology and markers of hepatic fibrosis. DIO-NASH mice treated with CHS-131 demonstrated a hepatic shift to diacylglycerols and triacylglycerols with a lower number of carbons, increased expression of genes stimulating fatty acid oxidation and browning, and decreased expression of genes promoting fatty acid synthesis, triglyceride synthesis, and inflammation in adipose tissue. Conclusion: CHS-131 improves liver histology in a DIO and biopsy-confirmed mouse model of NASH by altering the hepatic lipidome, reducing insulin resistance, and improving lipid metabolism and inflammation in adipose tissue.

Viral load and disease severity in COVID-19

The relationship between COVID-19 severity and viral load is unknown. Our objective was to assess the association between viral load and disease severity in COVID-19. In this single center observational study of adults with laboratory confirmed SARS-CoV-2, the first positive in-hospital nasopharyngeal swab was used to calculate the log10 copies/ml [log10 copy number (CN)] of SARS-CoV-2. Four categories based on level of care and modified sequential organ failure assessment score (mSOFA) at time of swab were determined. Median log10CN was compared between different levels of care and mSOFA quartiles. Median log10CN was compared in patients who did and did not receive influenza vaccine, and the correlation between log10CN and D-dimer was examined. We found that of 396 patients, 54.3% were male, and 25% had no major comorbidity. Hospital mortality was 15.7%. Median mSOFA was 2 (IQR 0-3). Median log10CN was 5.5 (IQR 3.3-8.0). Median log10CN was highest in non-intubated ICU patients [6.4 (IQR 4.4-8.1)] and lowest in intubated ICU patients [3.6 (IQR 2.6-6.9)] (p value < 0.01). In adjusted analyses, this difference remained significant [mean difference 1.16 (95% CI 0.18-2.14)]. There was no significant difference in log10CN between other groups in the remaining pairwise comparisons. There was no association between median log10CN and mSOFA in either unadjusted or adjusted analyses or between median log10CN in patients with and without influenza immunization. There was no correlation between log10CN and D-dimer. We conclude, in our cohort, we did not find a clear association between viral load and disease severity in COVID-19 patients. Though viral load was higher in non-intubated ICU patients than in intubated ICU patients there were no other significant differences in viral load by disease severity.

Cellular oxygen consumption in patients with diabetic ketoacidosis

BACKGROUND

Diabetic ketoacidosis (DKA) is a potentially life-threatening disorder associated with severe alterations in metabolism and acid-base status. Mitochondrial dysfunction is associated with diabetes and its complications. Thiamine and coenzyme Q10 (CoQ10) are important factors in aerobic metabolism. In this study, we measured cellular oxygen consumption rates (OCRs) and the effects of in vitro administration of thiamine and CoQ10 on OCRs in patients with DKA versus healthy controls.

METHODS

Blood samples were collected from a prospective cohort of patients with DKA and from controls. Cellular OCRs were measured in peripheral blood mononuclear cells (PBMC) without treatment and after treatment with thiamine, CoQ10, or both. The mitochondrial profile was measured using an XFe96 Extracellular Flux Analyzer and XF Cell Mito Stress Test Kit (Seahorse Bioscience). A linear quantile mixed model was used to compare OCRs and estimate treatment effects.

RESULTS

A total of 62 patients with DKA and 48 controls were included in the study. The median basal and maximal OCRs were lower in the DKA group than in the control group (basal: 4.7 [IQR: 3.3, 7.9] vs. 7.9 [5.0, 9.5], p = 0.036; maximal: 16.4 [9.5, 28.1] vs. 31.5 [20.6, 46.0] pmol/min/µg protein, p < 0.001). In DKA samples, basal and maximal OCRs were significantly increased when treated with thiamine, CoQ10, or both. In controls, basal and maximal OCR were significantly increased only with thiamine treatment.

CONCLUSION

Mitochondrial metabolic profiles of patients with DKA demonstrated lower cellular oxygen consumption when compared to healthy controls. Oxygen consumption increased significantly in cells of patients with DKA treated with thiamine or CoQ10. These results suggest that thiamine and CoQ10 could potentially have therapeutic benefits in DKA via their metabolic effects on mitochondrial cellular respiration.

The role of plant-based dietary patterns in reducing COVID-19 risk and/or severity in adults: A systematic review and meta-analysis of observational studies

BACKGROUND & AIMS

Plant-based dietary patterns (PBDs) might protect against COVID-19 risk and reduce severity of infection. This systematic review with meta-analysis aimed to examine the association between PBDs and risk of COVID-19 infection, hospitalization, intensive care unit (ICU) admission, and/or mortality, in adults.

METHODS

Pubmed, Embase, CINAHL and Web of Science were searched for observational studies, published in English up to 3rd April 2023, comparing the highest with the lowest adherence to a specific PBD. Data were screened, extracted, and risk of bias assessed using the Newcastle-Ottawa Quality Assessment Scale, by independent reviewers.

RESULTS

Seven studies (one cross-sectional, three case-control, and three prospective cohort), reporting on 649,315 participants, were eligible. Across them, there were 8512 events of COVID-19 infection (six studies), and 206 events of COVID-19 hospitalization (four studies), in addition to one study reporting on a composite hospitalization outcome (740 events). The pooled analysis showed that PBDs are associated with a 59% (odds ratio (OR) = 0.41, 95% confidence intervals (CI) 0.23-0.59; two studies) and 18% (OR = 0.82, 95% CI 0.78-0.85; three studies) reduction in COVID-19 infection risk in case-control and cohort studies, respectively. The pooled analysis of one case-control and two cohort studies showed an inverse association between high adherence to a PBD and risk of COVID-19 hospitalization (OR = 0.38, 95% CI 0.04-0.72).

CONCLUSION

Findings suggest a protective role of PBDs against the risk of COVID-19 infection and severity. More studies are needed to establish the association between PBDs and risk of ICU admission and mortality due to COVID-19.

Diabetic Ketoacidosis and Dysregulation of Proglucagon Family of Molecules

Objectives

An increasing body of evidence supports a significant contributory role for pancreatic α-cell dysfunction in the pathophysiology of diabetic ketoacidosis (DKA). In normal physiology, high glucose levels stimulate insulin and inhibit glucagon secretion, while low glucose stimulates glucagon but inhibits insulin release. This regulatory mechanism is progressively lost in diabetes mellitus (DM), where diminished insulin levels are accompanied by hyperglucagonemia leading to the further aggravation of hyperglycemia caused by insulin deficiency. Glucagon is produced via the posttranslational modification of proglucagon in a process that also produces other proglucagon molecules including major proglucagon fragment (MPGF) and glucagon like peptide-1 (GLP-1). Here we hypothesized that DKA is associated with α-cell dysfunction leading to elevated levels of proglucagon molecules.

Methods

We measured levels of glucagon, GLP-1 and MPGF as indices of glucagon synthesis/α-cell function in the plasma of patients with DKA and in healthy controls. The inclusion criteria for DKA patients were glucose &gt; 250 mg/dL, pH &lt; 7.2, bicarbonate &lt; 15mEq/L, presence of ketones and patients were part of a larger randomized trial. Samples were obtained at baseline prior to trial interventions. An independent sample t-test was used to compare differences.

Results

We analyzed samples of 25 healthy controls and 59 individuals with DKA (47 T1DM and 12 T2DM) and found significant increase in glucagon levels in all of the DKA groups (controls 47 pg/mL (36, 67), T1DM 63 (40,135), T2DM 84 (61,105), p = 0.013). The differences were significant in MPGF too (controls 0.5 ng/mL (0.4, 0.8), T1DM 1.1 (0.7, 1.9), T2DM 1.3 (0.9, 2.0), p &lt; 0.001), while differences in GLP-1 between groups did not reach statistical significance. C-peptide levels were significantly diminished in DKA and the levels of glucagon and C-peptide were strongly associated in healthy controls but not in DKA.

Conclusions

Our data indicate that proglucagon family molecules may be actively contributing to the pathogenesis of DKA and may represent a potential site for future therapeutic interventions.

Funding Sources

The parental study of “Thiamine as adjunctive therapy for diabetic ketoacidosis” was supported through a grant from the National Institute of Health.

Invasive Pleomorphic Lobular Carcinoma of the breast: Clinicopathological features, treatment patterns and outcomes

INTRODUCTION

Pleomorphic lobular carcinoma (PLC) is a rare variant of invasive lobular carcinoma of the breast (ILC) and few studies have reported controversial data regarding its outcomes. The information provided appears to indicate that PLC is more aggressive and has worse outcome when compared to classical ILC (cILC); however, due to its rarity, studies with a considerable cohort of patients are lacking. The purpose of this study was to compare the clinicopathological characteristics and disease outcomes of PLC patients to those with cILC in a large cohort from a single institution.

METHODS

A retrospective comparative study was performed, including 226 patients with PLC and 2067 patients with cILC operated at the European Institute of Oncology (EIO) between 2001 and 2018. The median follow-up period for both groups was 7 years.

RESULTS

5- and 10-years invasive disease-free survival were better in the matched classical lobular carcinoma patients compared to the pleomorphic variant. The 5- and 10-years overall survival confirmed the trend previously seen in favor of the classical variant, with a 5-year survival of 98.4% vs 83.6% and a 10-year survival of 93.4% vs 69.5%, respectively.

CONCLUSIONS

The pleomorphic variant has been confirmed to be characterized by worse clinicopathological characteristics and worse clinical outcomes than the classical variant.

OR01-5 Leptin Acts through Altering Energy Intake and Lipolysis to Reduce Body Weight but Has No Effect on Energy Expenditure, Physical Activity, and Sympathetic Nervous System in Humans

It remains unknown whether leptin regulates body weight in humans and whether this occurs through actions centrally and/or peripherally i.e. by altering hormone and sympathetic nervous system (SNS) activity in humans as it has been suggested by experiments in rodents. We explored body weight and body composition changes in response to short and long term leptin administration to lean humans and explored potential underlying mechanisms by studying changes in energy intake, energy expenditure, lipolysis and hormonal and SNS changes in response to leptin administered in physiological and supraphysiological doses in lean subjects. We utilized the following study designs: a) open-label long-term leptin replacement study aiming at keeping circulating leptin levels within the physiological range and b) randomized, placebo-controlled, long-term leptin replacement study aiming at keeping total body weight stable by adjusting leptin doses in females with acquired hypoleptinemia. To further explore underlying mechanisms we also performed a) short-term placebo vs. leptin physiological replacement study during a three day long fasting-induced hypoleptinemia in lean subjects; and b) short-term leptin dose escalation study to supraphysiological levels in the fed i.e. normoleptinemic vs. in fasting-induced hypoleptinemic state for three days in both lean and overweight individuals. Long-term leptin replacement decreased body weight (p-value<0.001) through decreasing fat mass (p-value<0.001) and without affecting lean mass. Underlying mechanisms included decreased energy intake with leptin (caloric intake - leptin association r=-0.644, p-value<0.001), but not energy expenditure. Leptin also increased lipolysis demonstrated by elevated free fatty acids which were increased in response to leptin at time points that corresponded to fat mass loss (p-value=0.01). Long- but not short-term leptin replacement downregulated the renin-angiotensin-aldosterone axis at time points corresponding to maximum lipolytic effects (p-value=0.024 renin; p-value=0.001 aldosterone). Importantly, no changes in heart rate, blood pressure and body temperature were demonstrated with leptin. Thus, leptin administration decreases body weight in lean subjects, without changes to lean mass, by acting through decreasing body fat primarily through lipolysis and decreased caloric intake.

Thiamine as a metabolic resuscitator after in-hospital cardiac arrest

INTRODUCTION

Elevated lactate is associated with mortality after cardiac arrest. Thiamine, a cofactor of pyruvate dehydrogenase, is necessary for aerobic metabolism. In a mouse model of cardiac arrest, thiamine improved pyruvate dehydrogenase activity, survival and neurologic outcome.

AIM

To determine if thiamine would decrease lactate and increase oxygen consumption after in-hospital cardiac arrest.

METHODS

Randomized, double-blind, placebo-controlled phase II trial. Adult patients with arrest within 12 hours, mechanically ventilated, with lactate ≥ 3 mmol/L were included. Randomization was stratified by lactate > 5 or ≤ 5 mmol/L. Thiamine 500 mg or placebo was administered every 12 hours for 3 days. The primary outcome of lactate was checked at baseline, 6, 12, 24, and 48 hours, and compared using a linear mixed model, accounting for repeated measures. Secondary outcomes included oxygen consumption, pyruvate dehydrogenase, and mortality.

RESULTS

Enrollments stopped after 36 patients due Data Safety and Monitoring Board concern about potential harm in an unplanned subgroup analysis. There was no overall difference in lactate (mean difference at 48 hours 1.5 mmol/L [95% CI -3.1-6.1], global p = 0.88) or any secondary outcomes. In those with randomization lactate > 5 mmol/L, mortality was 92% (11/12) with thiamine and 67% (8/12) with placebo (p = 0.32). In those with randomization lactate ≤ 5 mmol/L mortality was 17% (1/6) with thiamine and 67% (4/6) with placebo (p = 0.24). There was a significant interaction between randomization lactate and the effect of thiamine on survival (p = 0.03).

CONCLUSIONS

In this single center trial thiamine had no overall effect on lactate after in-hospital cardiac arrest.