Marina Michalaki

Effect of Oral Glutamine Administration on Bacterial Tanslocation, Endotoxemia, Liver and Ileal Morphology, and Apoptosis in Rats with Obstructive Jaundice

Postoperative complications in patients with obstructive jaundice remain increased when associated with endotoxemia and the inflammatory response due to gut barrier failure. Administration of glutamine has been proposed to maintain the integrity of the gut mucosa and thus reduce bacterial translocation (BT), but the effects of this pretreatment on apoptosis and histologic morphology of various organs affected by BT in obstructive jaundice have not been studied. We therefore studied the effects of oral glutamine supplementation on endotoxemia, BT, liver and terminal ileal morphology, and apoptosis in an experimental model of obstructive jaundice. A total of 60 male Wistar rats were randomly divided into four groups of 15 each: I, controls; II, sham-operated; III, bile duct ligation (BDL); IV, BDL + glutamine (4.5 g/kg/day in drinking water). Ileal samples for histology, DNA and protein content, liver biopsies, mesenteric lymph nodes (MLNs) for culture, and portal and systemic blood samples for endotoxin measurements were obtained 10 days later. Compared to the controls, a significant increase in contaminated MLN and liver samples and increased endotoxemia were noted in group III (p < 0.01) but were significantly reduced in group IV (p < 0.05). Group IV also had a significantly higher number of mitoses per crypt (M/c) (p < 0.05), less apoptotic body counts (ABCs) (p < 0.05), and a higher DNA content than did group III (p < 0.05). Liver biopsies from group III displayed typical changes of large duct obstruction that significantly improved after glutamine treatment, with decreased ductular proliferation.We concluded that supplementation of oral glutamine in the presence of obstructive jaundice ameliorates BT, endotoxemia, and apoptosis and improves the ileal and liver histology.

Stress-induced hyperglycemia in patients with severe sepsis: a compromising factor for survival.

Objective:To study the clinical and laboratory characteristics of patients with severe sepsis and baseline hyperglycemia and investigate the impact of hyperglycemia on the final outcome. Patients:A total of 265 patients admitted with severe sepsis in 3 major hospitals in South-Western Greece, during a 1-year period, were included in the study. Patients were divided in 3 groups according to their glycemic profile at admission: patients with stress hyperglycemia (group SH, n = 47), with diabetes mellitus (group DM, n = 65), and with normal glucose level (group NG, n = 153). Hyperglycemia was defined as an admission or in-hospital fasting glucose level of ≥126 mg/dL or a random blood glucose level of ≥200 mg/dL on ≥2 determinations. Results:A total of 42.2% of patients with severe sepsis had baseline hyperglycemia with 17.7% having sepsis-induced stress hyperglycemia. No family history was noted in the SH group. A higher percentage of septic patients with stress hyperglycemia died compared with patients with normal glucose levels (42.5% versus 13.7%) and diabetics (42.5% versus 24.6%). Group DM had also a poorer prognosis than group NG (24.6% versus 13.7%). A positive correlation was detected between the fasting blood glucose levels of group SH and the severity of sepsis indicated by sepsis-related organ failure assessment score. Conclusion:Baseline hyperglycemia, including stress-induced hyperglycemia, is common in patients with severe sepsis. Stress-induced hyperglycemia is related to a more severe disease and poorer prognosis.

Improved Levothyroxine Pharmacokinetics After Bariatric Surgery

BACKGROUND The absorption of levothyroxine (LT4) is affected by many factors. Bariatric surgery is recommended in severely obese patients. The aim of this study was to determine the consequences of bariatric surgery on LT4 pharmacokinetic parameters, and to identify the regions of the gastrointestinal tract where LT4 is absorbed in patients with severe obesity before and after surgery. METHODS We studied 32 severely obese nonhypothyroid patients who underwent sleeve gastrectomy (SG; n=10), Roux-en-Y gastric bypass (RYGBP; n=7), or biliopancreatic diversion with long limbs (BPD-LL; n=15). Before surgery, from 8:00 a.m., blood samples were collected before and every 30 minutes after the oral administration of a solution of 600 μg of LT4. The same procedure was repeated 35 days after surgery. We estimated the pharmacokinetic parameters of LT4 before and after surgery, including the area under the curve (AUC), the peak thyroxine concentration (Cmax), and the time to peak thyroxine concentration (Tmax). RESULTS Following surgery, in the SG group, the mean AUC was higher than it was before surgery (18.97±6.01 vs. 25.048±6.47 [μg/dL]·h; p<0.01), whereas the values of Cmax and Tmax were similar to those before surgery. In the RYGBP group, mean AUC, Cmax, and Tmax were similar before and after surgery. In the BPD-LL group, mean AUC and Cmax were higher after surgery than before (14.18±5.64 vs. 25.51±9.1 [μg/dL]·h, p<0.001; 5.62±1.34 vs. 8.16±2.57 μg/dL, p<0.001, respectively), whereas Tmax was similar. CONCLUSIONS The pharmacokinetic parameters of LT4 absorption are improved following SG and BPD-LL types of bariatric procedures. We conclude that the stomach, the duodenum, and the upper part of the jejunum are not sites for LT4 absorption, because in the above-mentioned bariatric procedures these are bypassed or removed.

Critical Illness-Related Corticosteroid Insufficiency in Patients With Cirrhosis and Variceal Bleeding

BACKGROUND & AIMS Relative adrenal insufficiency (AI) occurs in patients with cirrhosis with sepsis, but not with variceal bleeding. We evaluated adrenal function in cirrhotic patients with and without bleeding. METHODS Twenty cirrhotic patients with variceal bleeding were evaluated using the short synacthen test (SST) and 10 using the low-dose synacthen test (LDSST) followed by SST. The control group included 60 stable cirrhotic patients, assessed by LDSST (n = 50) or SST (n = 10), and 14 healthy volunteers. AI was diagnosed using SST, based on peak cortisol levels ≤ 18 μg/dL in nonstressed patients or Δmax <9 μg/dL or a total cortisol level <10 μg/dL in stressed patients with variceal bleeding-the current criteria for critical illness-related corticosteroid insufficiency. Using LDSST, diagnosis was based on peak concentrations of cortisol ≤ 18 μg/dL in nonstressed patients and <25 μg/dL (or Δmax <9 μg/dL) in patients with variceal bleeding. We evaluated patients with levels of serum albumin >2.5 g/dL, to indirectly assess cortisol binding. RESULTS All healthy volunteers had normal results from LDSSTs and SSTs. Patients with variceal bleeding had higher median baseline concentrations of cortisol (15.4 μg/dL) than stable cirrhotic patients (8.7 μg/dL, P = .001) or healthy volunteers (10.1 μg/dL, P = .01). Patients with variceal bleeding had higher median peak concentrations of cortisol than stable cirrhotic patients (SST results of 32.7 vs 21 μg/dL, P = .001; LDSST results of 9.3 vs 8.1 μg/dL; nonsignificant), with no differences in Δmax in either test. These differences were greater with variceal bleeding than in stable cirrhotic patients with AI. Subanalysis of patients with albumin levels >2.5 g/dL did not change these differences. CONCLUSIONS Cirrhotic patients with variceal bleeding have AI. Despite higher baseline concentrations of serum cortisol and subnormal Δmax values, they did not have adequate responses to stress, and therefore had critical illness-related corticosteroid insufficiency.

Hypothalamic–pituitary–adrenal axis response to the severity of illness in non-critically ill patients: does relative corticosteroid insufficiency exist?

OBJECTIVE Relative corticosteroid insufficiency may be common in critically ill patients and is associated with a poor outcome; however, the response of the hypothalamic-pituitary-adrenal (HPA) axis in nursed patients is not known. Our aim was to evaluate the response of HPA axis to the severity of illness in non-critically ill nursed (NCIN) patients and the clinical outcome. SUBJECTS AND METHODS Fifty-six nursed patients who were divided into four groups (stroke, mild disease, sepsis and severe sepsis) as well as a control group (n=15) were studied. At admission (day 1), cortisol and ACTH were measured and a low-dose (1 microg) corticotrophin test was performed, followed 2 h later by a standard-dose (250 microg) corticotrophin test. Diurnal variation of cortisol was obtained on day 2. A second identical set of low-dose and standard-dose corticotrophin tests were performed on day 5 or 6 (recovery phase). Results In patients with stroke and severe sepsis, cortisol had the highest values and its diurnal variation was abolished. Dissociation of ACTH and cortisol was found in all patients. The Delta(max) of cortisol after the 1-microg corticotrophin test did not differ among the groups, while after the 250-microg corticotrophin test, it was borderline higher in controls. The ratio of responders (Delta(max) of cortisol >or=9 microg/dl) to non-responders after 1- or 250-microg corticotrophin test did not differ among patients and controls. All patients had a good outcome without glucocorticoid treatment. CONCLUSIONS Depending on the severity of illness, mild alterations in the HPA axis occurred. However, relative corticosteroid insufficiency was not confirmed in NCIN patients.

Adipokines levels are associated with the severity of liver disease in patients with alcoholic cirrhosis

AIM To investigate the adipokine levels of leptin, adiponectin, resistin, visfatin, retinol-binding protein 4 (RBP4), apelin in alcoholic liver cirrhosis (ALC). METHODS Forty non-diabetic ALC patients [median age: 59 years, males: 35 (87.5%), Child-Pugh (CP) score: median 7 (5-12), CP A/B/C: 18/10/12, Model for End-stage Liver Disease (MELD): median 10 (6-25), follow-up: median 32.5 mo (10-43)] were prospectively included. The serum adipokine levels were estimated in duplicate by ELISA. Somatometric characteristics were assessed with tetrapolar bioelectrical impedance analysis. Pearsons rank correlation coefficient was used to assess possible associations with adipokine levels. Univariate and multivariate Cox regression analysis was used to determine independent predictors for overall survival. RESULTS Body mass index: median 25.9 (range: 20.1-39.3), fat: 23.4% (7.6-42.1), fat mass: 17.8 (5.49-45.4), free fat mass: 56.1 (39.6-74.4), total body water (TBW): 40.6 (29.8-58.8). Leptin and visfatin levels were positively associated with fat mass (P < 0.001/P = 0.027, respectively) and RBP4 with TBW (P = 0.025). Median adiponectin levels were significantly higher in CPC compared to CPA (CPA: 7.99 ± 14.07, CPB: 7.66 ± 3.48, CPC: 25.73 ± 26.8, P = 0.04), whereas median RBP4 and apelin levels decreased across the spectrum of disease severity (P = 0.006/P = 0.034, respectively). Following adjustment for fat mass, visfatin and adiponectin levels were significantly increased from CPA to CPC (both P < 0.001), whereas an inverse correlation was observed for both RBP4 and apelin (both P < 0.001). In the multivariate Cox regression analysis, only MELD had an independent association with overall survival (HR = 1.53, 95%CI: 1.05-2.32; P = 0.029). CONCLUSION Adipokines are associated with deteriorating liver function in a complex manner in patients with alcoholic liver cirrhosis.

Cortisol in tissue and systemic level as a contributing factor to the development of metabolic syndrome in severely obese patients

CONTEXT Adrenal and extra-adrenal cortisol production may be involved in the development of metabolic syndrome (MetS). OBJECTIVE To investigate the activity of the hypothalamic-pituitary-adrenal (HPA) axis and the expression of HSD11B1, nuclear receptor subfamily 3, group C, member 1 (glucocorticoid receptors) α (NR3C1α) and β (NR3C1β) in the liver, subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) of severely obese patients with and without MetS. METHODS The study included 37 severely obese patients (BMI ≥ 40 kg/m(2)), 19 with MetS (MetS+ group) and 18 without (MetS- group), studied before and during bariatric surgery. Before the day of surgery, urinary free cortisol (UFC) and diurnal variation of serum and salivary cortisol were estimated. During surgery, biopsies of the liver, VAT and SAT were obtained. The expression of HSD11B1, NR3C1α and NR3C1β was evaluated by RT-PCR. RESULTS UFC and area under the curve for 24-h profiles of serum and salivary cortisol were lower in the MetS- group. In the MetS- group, mRNA levels of HSD11B1 in liver exhibited a negative correlation with liver NR3C1α (LNR3C1α) and VAT expression of HSD11B1 was lower than the MetS+ group. CONCLUSIONS We observed a downregulation of the NR3C1α expression and lower VAT mRNA levels of HSD11B1 in the MetS- group, indicating a lower selective tissue cortisol production and action that could protect these patients from the metabolic consequences of obesity. In the MetS- group, a lower activity of the HPA axis was also detected. Taken together, cortisol in tissue and systematic level might play a role in the development of MetS in severely obese patients.

Activated hypothalamic pituitary adrenal axis in patients with metabolic syndrome.

Metabolic syndrome (MetS) is correlated with the activity of hypothalamic-pituitary-adrenal axis (HPA), but the underlying mechanism still remains elusive. The aim of this study was to investigate the HPA axis function in patients with MetS. This case-control study included 159 people. They were divided into 2 groups. The first group included 73 healthy volunteers (control group: 19 males, 54 females, mean±SD: 49.9±7.5 years old, with BMI: 27.9±4.42 kg/m2) and the second group included 86 patients with MetS (case group: 48 males, 38 females, mean±SD: 52.2±7.6 years old, with BMI: 30.5±5.35 kg/m2). An oral glucose tolerance test (OGTT) was performed for all subjects after a 12-h overnight fast, and blood samples were obtained for determination of ACTH, cortisol, insulin, C-peptide, and glucose levels. Serum cortisol after an overnight dexamethasone suppression test was determined in both groups. Patients with MetS had serum cortisol levels after an overnight dexamethasone suppression test significantly higher than controls. During OGTT plasma ACTH levels were higher at all time points in patients with MetS compared to controls, whereas serum cortisol levels were comparable between the 2 groups. Plasma ACTH during OGTT was also correlated with most of the components of MetS. The HPA axis in patients with MetS seems to be more active as evidenced by the higher cortisol levels after the overnight dexamethasone suppression test and by the higher ACTH levels during OGTT. This functional hypercortisolism might be involved in the pathogenesis of the metabolic syndrome.

MECHANISMS IN ENDOCRINOLOGY: Aging and anti-aging: a Combo-Endocrinology overview

Aging and its underlying pathophysiological background has always attracted the attention of the scientific society. Defined as the gradual, time-dependent, heterogeneous decline of physiological functions, aging is orchestrated by a plethora of molecular mechanisms, which vividly interact to alter body homeostasis. The ability of an organism to adjust to these alterations, in conjunction with the dynamic effect of various environmental stimuli across lifespan, promotes longevity, frailty or disease. Endocrine function undergoes major changes during aging, as well. Specifically, alterations in hormonal networks and concomitant hormonal deficits/excess, augmented by poor sensitivity of tissues to their action, take place. As hypothalamic-pituitary unit is the central regulator of crucial body functions, these alterations can be translated in significant clinical sequelae that can impair the quality of life and promote frailty and disease. Delineating the hormonal signaling alterations that occur across lifespan and exploring possible remedial interventions could possibly help us improve the quality of life of the elderly and promote longevity.

Impaired Pharmacokinetics of Levothyroxine in Severely Obese Volunteers

BACKGROUND Suppressive or replacement doses of levothyroxine (LT4) are affected by the rate and extent of the active ingredient absorbed, as well as by the lean body mass. Obesity has reached epidemic proportions worldwide and is related with many comorbidities. The aim of this study was to determine the pharmacokinetic parameters of LT4 in severely obese individuals and compared them with similar data in lean control subjects. METHODS We studied 62 euthyroid subjects who had negative tests for anti-thyroid peroxidise antibodies (Ab-TPO). Thirty eight of these subjects were severely obese but otherwise healthy (severe obese subjects [SOS] group). Twenty-four were healthy control subjects (control group), with a body mass index of 23.3 ± 1.7 kg/m(2). Subjects received 600 μg oral sodium LT4 after an overnight fast. Serum triiodothyronine (T3), T4, and thyroid-stimulating hormone were measured at baseline. Serum T4 and T3 was measured 0.5, 1, 1.5, 2, 2.5, 3, and 4 hours after LT4 administration. RESULTS Baseline serum T4 and thyroid-stimulating hormone concentrations were higher in the SOS group than in the control group; serum T3 was similar in the two groups. The corrected area under the curve and the maximum T4 concentration after LT4 administration were lower, whereas the time to maximum concentration from the baseline was higher in SOS than in the control group. The estimated plasma volume was higher in the SOS than in the control group. Mean serum T3 levels increased gradually during the four hours after LT4 administration in the control group. In contrast, they decreased gradually in the SOS group. CONCLUSIONS Severely obese individuals may need higher LT4 suppressive or replacement doses than normal-weight individuals due, among other factors, to impaired LT4 pharmacokinetic parameters. The latter could be attributed to their higher plasma volume and/or to delayed gastrointestinal LT4 absorption. T4 conversion to T3 might be defective in severe obesity.