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Biomedical subjects

A V Greco

Publications and source records attributed to A V Greco.

At least 37 records · Page 2Linked to original sources
PubMed2000

Serum leptin levels in post-hepatitis liver cirrhosis.

BACKGROUND/AIMS: Little information is available on the involvement of leptin in clinical conditions associated with malnutrition, such as liver cirrhosis. The behaviour of serum leptin in patients with different Child-Pugh score, post-hepatitis liver cirrhosis and insulin sensitivity has therefore been investigated and compared with that in alcoholic Child C patients. METHODS: Sixty-four patients, aged 51 to 62 years, with different degrees of post-hepatitis cirrhosis or Child C alcoholic cirrhosis were compared with 15 age-matched control subjects. Body composition was estimated by skinfold thickness. Serum leptin, glucose and insulin were assayed. RESULTS: In post-hepatitis patients a significant reduction in leptin levels was observed as the Child-Pugh score worsened (men: 2.94+/-1.61 in Child C vs 6.78+/-2.49 ng/ml in controls, p<0.001; women: 4.14+/-0.66 in Child C vs 16.16+/-3.90 ng/ml in controls, p<0.02). Conversely, only the men with alcoholic liver cirrhosis showed a significant difference in leptin concentration compared to controls (8.5+/-2.1 vs 16.4+/-7.9 kg, p<0.05). In particular, Child C, alcoholic cirrhotic women had a significantly (p=0.03) higher level of leptin than post-hepatitis matched women. A positive correlation was observed between leptin and fat mass (men R2=0.59, p<0.0001 and women R2=0.65, p<0.0001). While fasting levels of serum leptin correlated significantly with insulin concentrations in controls, a similar relationship was not observed in the cirrhotic population, which displayed higher insulin concentrations than controls. CONCLUSIONS: In contrast to findings in alcoholic cirrhotic women, low leptin values in post-hepatitis cirrhotic patients mainly represent the expression of a reduced fat mass.

Adipose Tissue↗
PubMed2000

Acetyl-L-carnitine infusion increases glucose disposal in type 2 diabetic patients.

Little information is available in the literature on the effect of L-carnitine to improve glucose disposal in healthy control subjects and type 2 diabetic patients. No data are reported on the pharmacological properties of acetyl-L-carnitine (ALC) in type 2 diabetes mellitus. The present study evaluates glucose uptake and oxidation rates with either ALC or placebo administration in 18 type 2 diabetic patients. On different days, each patient received both a primed-constant infusion of ALC (5 mg/kg body weight [BW] priming bolus and either 0.025, 0.1, or 1.0 mg/kg BW/min constant infusion) and a comparable placebo formulation. During the infusion period, continuous indirect calorimetric monitoring and a euglycemic-hyperinsulinemic clamp (EHC) study were performed. The total end-clamp glucose tissue uptake (M value) was significantly increased by the administration of ALC (from 3.8 to 5.2 mg/kg/min, P = .006), and the dose dependence of this effect reached borderline statistical significance (P = .037). The increase in the M/I ratio was also highly significant after ALC administration (from 3.9 to 5.8 x 10(-2) mg/kg/min/(microUI/mL, P < .001), while no statistically significant effect was attributable to the different dosages. The increase in the M value was related to increased glucose storage (highly significant effect of ALC) rather than increased glucose oxidation (no statistical significance). In conclusion, the effect of ALC on glucose disposal has no relationship to the amount administered. This could be due to an effect of ALC on the enzymes involved in both the glycolytic and gluconeogenetic pathways, and a possible reversibility of glycogen synthase inhibition in diabetic subjects.

Acetylcarnitine↗
PubMed2000

Body composition and energy expenditure after weight loss following bariatric surgery.

OBJECTIVES: To assess the effectiveness of biliopancreatic diversion (BPD) in the treatment of morbid obesity and to evaluate how the procedure affects body weight. SUBJECTS: Fourteen morbidly obese subjects studied before and 30 months after BPD and fifteen healthy volunteers matched for age, sex and height (controls). METHODS: Comparison of the following parameters were made in the study groups before surgery and 30 months after BPD and with those of the controls group: fat mass, fat-free mass, non-protein substrate oxidation, basal metabolic rate, plasma glucose, insulin and free fatty acid concentrations. RESULTS: Obese subjects lost 60.38+/-10.71 kg of weight during 18 months following surgery and then remained stable for another 12 months, when this study was performed. Weight loss was substantially due to a loss of fat mass (FM: 60.13+/-13.01 kg before and 19.02+/-8.61 kg after BPD; p<0.001). FM were not statistically different between post-obese subjects and controls; however, post-obese patients retained significantly more fat free mass (FFM) than controls. Subsequently, basal metabolic rates of post-obese subjects were higher than those of the control group (p<0.05). Fasting non-protein respiratory quotient (npRQ) was significantly lower before BPD than 30 months after the surgery (0.798+/-0.04 vs. 0.90+/-0.048, p<0.001), suggesting that, while obese, patients oxidized more lipids than carbohydrates. Moreover, fasting and two-hour plasma glucose and insulin concentrations decreased significantly after BPD to values comparable to those of the control group. CONCLUSION: Weight loss in obese patients after BPD is mainly due to lipid malabsorption, but increased energy expenditure associated with retaining a high FFM in physically active post-obese subjects may also play a role, enabling them to maintain long-term reduced body weights.

Adult↗
PubMed2000

Changes in body composition, substrate oxidation, and resting metabolic rate in adult celiac disease patients after a 1-y gluten-free diet treatment.

BACKGROUND: The incidence of celiac disease has been on the rise in both Europe and the United States. Celiac disease patients are at high risk of undernutrition because of nutrient malabsorption. OBJECTIVE: The aim of the present study was to evaluate changes in body composition and energy metabolism in a group of patients with celiac disease before and after consumption of a gluten-free diet (GFD). DESIGN: Body composition (by anthropometry and isotopic dilution), resting metabolic rate (RMR), and substrate oxidation rates (by indirect calorimetry) were assessed in 39 adult celiac disease patients (16 men and 23 women) with a mean (+/-SD) age of 29. 9 +/- 7.6 y, weight of 58.3 +/- 6.6 kg, and percentage body fat of 20.1 +/- 6.7%, and in 63 (29 men and 34 women) age- and height-matched control subjects (age: 33.2 +/- 8.1 y; weight: 66.8 +/- 6.6 kg; and percentage body fat: 25.4 +/- 3.7%). Celiac disease patients were studied twice, at diagnosis and 1 y after treatment with a GFD. RESULTS: Before treatment, celiac disease patients had a lower body weight (P < 0.05) and a higher carbohydrate oxidation rate (P < 0.01) than did control subjects. Carbohydrate oxidation rates correlated positively with fecal lipid loss in untreated celiac disease patients (r = 0.80, P < 0.0001). After the GFD, percentage body fat was higher in celiac disease patients than in control subjects (P < 0.01), and lipid intakes tended to be higher than before treatment. CONCLUSIONS: This longitudinal study showed that the GFD treatment significantly increased body fat stores. Untreated patients preferentially utilized carbohydrates as a fuel substrate, probably as a consequence of both lipid malabsorption and a high carbohydrate intake, and lipid utilization increased with the restoration of the intestinal mucosa.

Adolescent↗
PubMed2000

Effect of a vegetable-protein-rich polymeric diet treatment on body composition and energy metabolism in inactive Crohn's disease.

OBJECTIVE: Since malnutrition and lactose intolerance are frequently reported in Crohn's disease (CD), we evaluated the differences in terms of compliance-to-treatment and nutritional status in inactive CD patients after two different treatments using either a standard polymeric diet or a vegetable-protein-rich and lactose-free diet. STUDY DESIGN: A case-control study. SUBJECTS: Forty CD patients with inactive disease were randomly divided into two groups. Group A (10 men; aged 33.9+/-7.2 years; BMI, 21.8+/-1.7 kg/m2) received a conventional polymeric enteral diet, while group B (10 men; aged 35.6+/-6.8 years; BMI, 21.4+/-1.8 kg/m2) was administered a soy-rich and lactose-free polymeric diet, over a 4-week period. METHODS: All the patients had a clinical and laboratory examination. Body composition was assessed by isotopic dilution and resting metabolic rate (RMR), and substrate oxidation rates were measured by indirect calorimetry. RESULTS: Body weight significantly increased after treatment in both groups (A, P<0.05; and B, P<0.01), as well as fat-free mass (A, P<0.05; and B, P<0.05) and fat mass (A, P<0.05; and B, P<0.01). RMR slightly increased, although it did not reach statistical significance. Treatment did not influence substrate oxidation rates. Group B lactose-intolerant patients reported a greater compliance-to-treatment than those in group A. CONCLUSIONS: This study showed that a polymeric enteral diet rich in vegetable protein and not containing milk protein, eaten at home, with no need for positioning a nasogastric tube, significantly improved body composition in inactive and lactose-intolerant CD patients, with no effect on energy metabolism, suggesting that it could be useful in improving nutritional status in these patients.

Adult↗
PubMed2000

Oxidation of [1,12-14C]dodecanedioic acid by rat pancreatic islets.

Several aliphatic dioic acids were recently reported to stimulate insulin release in isolated rat pancreatic islets incubated at close-to-physiological D-glucose concentrations. In order to gain insight into the mode of action of these acids in pancreatic islet B-cells, the oxidation of [1,12-14C]dodecanedioic acid (5.0 mM) was now measured in rat islets. Expressed as pmol of [1, 12-14C]dodecanedioic acid equivalent, the production of 14CO2 was close to 1.0 pmol/islet per 120 min, representing about 8% of that attributable to the oxidation of D-[U-14C]-glucose (8.3 mM). The dioic acid and the hexose failed to exert any significant reciprocal effect upon their respective oxidation rate. These findings support the view that the insulinotropic action of dodecanedioic acid, and presumably other aliphatic dioic acids, is causally linked to their capacity to act as nutrients in pancreatic islet cells.

Animals↗
PubMed2000

Disposition of dodecanedioic acid in humans.

The disposition of dodecanedioic acid (C12) was investigated in six overnight-fasting healthy male volunteers, who received a 165-min i. v. infusion of 42.45 mmol of C12 added to 150 microCi of [1-12-(14)C]C12. Blood samples were collected up to 360 min after the start of infusion, and concentration of serum labeled C12 was determined. Expired radioactivity (microCi/min) was measured up to 600 min and at 24 h. The 24-h C12 urinary excretion was around 5% of the administered amount. The percentage of C12 oxidized was 81.7 +/- 9.5% (mean +/- S.D.) of administered amount as estimated from the area under the curve of measured (14)CO(2) expiration rate. C12 kinetics was described by assuming a single compartment. A saturable rate of C12 tissue uptake (model A) and a linear rate of tissue uptake (model B) were considered. The kinetics of CO(2) produced by C12 oxidation was described by a fast pathway acting in parallel to a slow pathway modeled by first order kinetics. Parameters of model B were estimated for each subject, whereas model A was identified by fitting the pooled data of all subjects. On the basis of estimates obtained from model B, an average calorie delivery of 500 kcal/day was predicted in the plateau phase for the infusion rate of our experiments. When estimated from model A, the maximal rate of tissue uptake was 0.38 +/- 0.08 mmol/min, with a maximal calorie delivery of 750 kcal/day. These results appear promising for C12 utilization in parenteral nutrition, because C12 elimination with urine is low, whereas tissue uptake and oxidation are rather efficient.

Adult↗
PubMed2000

Subclinical hepatic encephalopathy: role of tryptophan binding to albumin and the competition with indole-3-acetic acid.

BACKGROUND: The role of tryptophan (TRY) and its metabolites in the pathogenesis of hepatic encephalopathy is conflicting. The aim of the present study is to investigate in posthepatitis cirrhotic patients with encephalopathy the serum levels of TRY and those of its metabolite indole-3-acetic acid, as well as TRY binding curve to serum albumin and the competition with indole-3-acetic acid. The presence of a relationship between encephalopathy severity and circulating free TRY was also investigated. METHODS: Serum TRY and indole-3-acetic acid were analyzed by HPLC; binding of TRY to serum albumin and the competition with indole-3-acetic acid was studied by equilibrium dialysis. RESULTS: Serum-free TRY was significantly higher in cirrhotic patients (43.33 +/- 14.70 vs 28.87 +/- 8.77 mumol/L, P = 0.02). The binding capacity of albumin was reduced in cirrhotics and further decreased by the addition of indole-3-acetic (K = 6.63 +/- 0.97 x 10(3) mol/L-1, gamma = 1.16 +/- 0.45 x 10(2) mol/L-1 in normal sera vs K = 1.04 +/- 0.20 x 10(3) mol/L-1, gamma = 1.91 +/- 0.92 10(2) mol/L-1 in cirrhotic sera). A multivariate analysis showed that among the psychometric tests the only independent predictor of serum levels of free TRY was the Block Design (R2 = 0.94, B = 0.16 +/- 0.01, beta = 0.97; P < 0.0001). CONCLUSIONS: A high percent ratio of free/total TRY and indoleacetic acid (IAA) was found in cirrhotic patients with hepatic encephalopathy. The concentrations of serum-free IAA and TRY correlated with the degree of subclinical encephalopathy, suggesting a role of these compounds in the development of mental derangement in liver cirrhosis.

Adult↗
PubMed2000

Effects of aliphatic dioic acids and glycerol-1,2,3-tris(dodecanedioate) on D-glucose-stimulated insulin release in rat pancreatic islets.

Aliphatic dioic acids have been proposed as alternative nutrients in selected clinical situations. In this study, their possible insulinotropic action was investigated in isolated rat pancreatic islets prepared from fed rats. Azelaic acid, sebacic acid and tridecanedioic acids, when tested at a 10.0 mm concentration, were found to augment insulin release evoked by D-glucose (7.0 mm) in the pancreatic islets. Likewise, glycerol-1,2,3-tris(dodecanoedioate), when used at concentrations close to 1.0 mm, increased the secretory response to the hexose. It is speculated that these findings may extend to insulin-producing cells, the knowledge that aliphatic dioic acids or their esters may act as energy substrates, e.g. in parenteral nutrition.

Animals↗
PubMed1999

Comparison of insulin response to intravenous glucose in healed myocardial infarction, in "cooled-off" unstable and stable angina pectoris, and in healthy subjects.

Fasting and postglucose hyperinsulinemia are recognized risk factors for acute coronary events. The insulin reactivity of patients with acute coronary syndromes, however, has not been carefully compared with that of patients with chronic stable angina. We used Bergman's minimal model to analyze the insulin response to intravenous glucose in 21 subjects: 8 patients with previous (>3 months) acute coronary syndrome but no effort-related angina; 6 patients with stable effort angina but no prior acute event; and 7 healthy controls. Diabetes mellitus, systemic hypertension, dyslipidemias, and obesity were excluded. All patients underwent coronary angiography. Insulin sensitivity, glucose effectiveness, and glucose tolerance were determined from insulin and glucose concentrations measured frequently up to 3 hours after a 0.33 g/kg intravenous glucose bolus. Patients with previous unstable angina or acute myocardial infarction had less extensive disease at angiography than patients with stable angina (p = 0.007). Both patient groups had higher basal and 180-minute insulinemia than controls (p <0.0007). However, patients with stable angina did not differ significantly from controls with regard to early and late insulinemic response to glucose. In contrast, patients with previous acute onset of ischemia had significantly greater 180-minute integrated insulinemia (p = 0.04) and reduced insulin sensitivity (p = 0.05) after the glucose challenge than did the stable angina group. These data suggest that patients with acute presentation of coronary artery disease, compared with patients with uncomplicated chronic stable angina, have an impaired insulin response to glucose despite less extensive coronary disease at angiography.

Analysis of Variance↗
PubMed1999

A new HPLC method for the direct analysis of triglycerides of dicarboxylic acids in biological samples.

Dicarboxylic acids (DA) are alternate lipid substrates recently proposed in parenteral nutrition. Two new derivatives of DA, a triglyceride of sebacic (TGC10) and one of dodecanedioic (TGC12) acid have been synthesised in order to reduce the amount of sodium given with the unesterified forms. The present paper describes a rapid and direct high-performance liquid chromatographic method (HPLC) for the analysis of these substances in both plasma and urine. Thirty-six male Wistar rats were rapidly injected with 64 mg of TGC10 or 53 mg of TGC12. The triglycerides and their products of hydrolysis were measured in plasma samples taken at different times. For the dose of 500 ng the intra-assay variations ranged from 6. 80+/-0.35% for TGC10 to 18.6+/-3.20% for TGC12 and the inter-assay variations were from 4.44+/-2.21% for TGC10 to 15.0+/-6.72% for TGC12. The detection limit for both triglycerides was 5 ng. This rapid and direct HPLC method could have practical implications in monitoring the concentration of both triglycerides and free forms of DA in biological samples of patients who might benefit from the administration of these substances during parenteral nutrition regimens.

Animals↗
PubMed1999

Multivariate identification of metabolic features in inflammatory bowel disease.

Weight loss and malnutrition are commonly reported in inflammatory bowel disease (IBD), but differences between Crohn's disease (CD) and ulcerative colitis (UC) patients have rarely been pointed out. In this regard, a sample of 102 consecutive patients with a diagnosis of either CD (n = 63, 33 males) or UC (n = 39, 25 males) based on previously reported clinical, morphologic, and histopathologic criteria were studied. Twenty-six anthropometric and metabolic variables were measured upon admission. Body composition was assessed by both anthropometry and bioimpedance measurements, and energy expenditure and substrate oxidation were assessed by indirect calorimetry. The data were subjected to principal-component analysis and to factor rotation to derive a set of a few basic independent descriptors of the metabolic features of each subject. Six descriptors were found to be responsible for greater than 86% of the total sample variability and to associate very well with mutually disjoint subsets of the original variables. The six summarizing factors are listed in order of decreasing percentage of explained variation (size 41.8%, fatness 17.9%, fuel 12.2%, shape 5.4%, energy 5.2%, and steroid 3.9%). CD and UC patients differed significantly with respect to fatness (CD lower, P = .004) and carbohydrate (CHO) fuel preference (CD lower, P = .030). Hence, CD patients showed a reduced fat mass (FM) compared with UC patients, and from a metabolic point of view, too, CD and UC are not superimposable. In fact, the lower CHO oxidation (CHOox) rate and consequent preferential lipid utilization found in CD patients may be taken into account as a contributing cause of lipid tissue wasting and in planning therapeutic enteral regimens.

Adolescent↗
PubMed1999

Glucose metabolism and insulin sensitivity in inactive inflammatory bowel disease.

BACKGROUND: Inflammatory mediator concentration was found to be increased in active inflammatory bowel disease, and this could be related to an insulin-resistant state. Moreover, glucocorticoids, which are widely used in the treatment of inflammatory bowel disease, are notoriously related to insulin resistance. AIM: To measure body composition, whole body glucose uptake and oxidation in Crohn's disease and ulcerative colitis patients with inactive disease. METHODS: All patients had clinical, ultrasound and biochemical assessment. Body composition was determined by isotopic dilution technique; basal metabolic rate and substrate oxidation were measured by indirect calorimetry. Insulin sensitivity was assessed by the euglycaemic hyperinsulinaemic clamp. Ten patients with inactive Crohn's disease (five males, aged 31.1 +/- 7.0 years) and 10 patients with inactive ulcerative colitis (five males, aged 33.4 +/- 8.8 years) participated in the study. Forty healthy subjects, matched for age and height were used as a control group. RESULTS: Crohn's disease patients showed lower BMI (P < 0.001), fat mass (P < 0.05) and respiratory quotient (P < 0.001) values compared to both ulcerative colitis and control subjects. No difference in peripheral glucose uptake (micromol/kg/min) was found between groups (respectively 42.5 +/- 6.78 in Crohn's disease, 40.2 +/- 8.00 in ulcerative colitis and 41.4 +/- 10.8 in control subjects). Glucose storage and oxidation did not differ between groups. CONCLUSION: Our data showed that inflammatory bowel disease patients in a remission phase of the disease activity had a whole body glucose uptake and oxidation similar to those of control subjects, probably due to fat-free mass preservation and low blood and tissue cytokine concentration.

Adolescent↗
PubMed1999

L-carnitine improves glucose disposal in type 2 diabetic patients.

OBJECTIVE: Aim of the present study is to evaluate the effects of L-carnitine on insulin-mediated glucose uptake and oxidation in type II diabetic patients and compare the results with those in healthy controls. DESIGN: Fifteen type II diabetic patients and 20 healthy volunteers underwent a short-term (2 hours) euglycemic hyperinsulinemic clamp with simultaneous constant infusion of L-carnitine (0.28 micromole/kg bw/minute) or saline solution. Respiratory gas exchange was measured by an open-circuit ventilated hood system. Plasma glucose, insulin, non-esterified fatty acids (NEFA) and lactate levels were analyzed. Nitrogen urinary excretion was calculated to evaluate protein oxidation. RESULTS: Whole body glucose uptake was significantly (p<0.001) higher with L-carnitine than with saline solution in the two groups investigated (48.66+/-4.73 without carnitine and 52.75+/-5.19 micromoles/kg(ffm)/minute with carnitine in healthy controls, and 35.90+/-5.00 vs. 38.90+/-5.16 micromoles/kg(ffm)/minute in diabetic patients). Glucose oxidation significantly increased only in the diabetic group (17.61+/-3.33 vs. 16.45+/-2.95 micromoles/kg(ffm)/minute, p<0.001). On the contrary, glucose storage increased in both groups (controls: 26.36+/-3.25 vs. 22.79+/-3.46 micromoles/kg(ffm)/minute, p<0.001; diabetics: 21.28+/-3.18 vs. 19.66+/-3.04 micromoles/kg(ffm)/minute, p<0.001). In type II diabetic patients, plasma lactate significantly decreased during L-carnitine infusion compared to saline, going from the basal period to the end-clamp period (0.028+/-0.0191 without carnitine and 0.0759+/-0.0329 with carnitine, p<0.0003). CONCLUSIONS: L-carnitine constant infusion improves insulin sensitivity in insulin resistant diabetic patients; a significant effect on whole body insulin-mediated glucose uptake is also observed in normal subjects. In diabetics, glucose, taken up by the tissues, appears to be promptly utilized as fuel since glucose oxidation is increased during L-carnitine administration. The significantly reduced plasma levels of lactate suggest that this effect might be exerted through the activation of pyruvate dehydrogenase, whose activity is depressed in the insulin resistant status.

Analysis of Variance↗
PubMed1999

Elevated diet-induced thermogenesis and lipid oxidation rate in Crohn disease.

BACKGROUND: Although malnutrition is frequently observed in Crohn disease (CD), its cause is not clear. Regulation of energy metabolism and diet-induced thermogenesis (DIT) have not been adequately studied in CD. OBJECTIVE: The aim was to study DIT and substrate oxidation in patients with inactive ileal CD. DESIGN: After a test meal providing 50.2 kJ/kg body wt, DIT was assessed by indirect calorimetry performed over 360 min in 18 CD patients and 12 healthy volunteers matched for age, sex, weight, and height. Body composition was evaluated with the labeled-water-bolus injection technique. RESULTS: Fat-free mass did not differ significantly between groups, but CD patients had markedly lower fat mass than control subjects (13.8+/-5.63 compared with 19.0+/-3.49 kg; P < 0.001). Nonprotein respiratory quotient was lower in CD patients than control subjects (0.80+/-0.04 compared with 0.86+/-0.03; P < 0.001). Average respiratory quotient between 75 and 150 min after the test meal was 0.85+/-0.03 in CD patients and 0.91+/-0.02 in control subjects (P < 0.001). Lipid oxidation rate was higher in CD patients than in control subjects (2.26+/-1.13 compared with 1.50+/-0.75 kJ/min; P < 0.05). DIT was higher in CD patients than in control subjects (9.89+/-1.93% compared with 5.67+/-0.91% of energy intake; P < 0.001). CONCLUSIONS: Patients with inactive ileal CD had significantly higher DIT and lipid oxidation rate than do healthy volunteers. These results may explain why CD patients have difficulty maintaining adequate nutritional status, and the findings also suggest that a diet relatively rich in fat may attain better energy balance.

Adult↗