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Nazario Melchionda

    Nazario Melchionda

    Obesity is a major risk factor for several metabolic diseases, frequently clustering to form the metabolic syndrome, carrying a high risk of cardiovascular mortality. We aimed to assess the prevalence of the metabolic syndrome in... more
    Obesity is a major risk factor for several metabolic diseases, frequently clustering to form the metabolic syndrome, carrying a high risk of cardiovascular mortality. We aimed to assess the prevalence of the metabolic syndrome in treatment-seeking obese subjects and the potential protective effect of physical activity. A cross-sectional analysis of data from a large Italian database of treatment-seeking obese subjects was performed. The metabolic syndrome was defined according to the criteria provisionally set by the National Cholesterol Education Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults, based on waist circumference, fasting glucose, triglyceride (TG) and high-density lipoprotein-cholesterol (HDL-C) levels, and arterial pressure. Data were available in 1,889 Caucasian subjects, 78% females, from 25 obesity centers. Minimum criteria for the metabolic syndrome were fulfilled in 53% of cases. The prevalence increased with age and obesity...
    We evaluated the effect of a 500-ml intragastric balloon (Ballobes) on some aspects of eating-related behaviour and weight loss on nine massively obese patients. An 800-kcal mixed meal test was performed some days before, 2-3 days and 2... more
    We evaluated the effect of a 500-ml intragastric balloon (Ballobes) on some aspects of eating-related behaviour and weight loss on nine massively obese patients. An 800-kcal mixed meal test was performed some days before, 2-3 days and 2 months after the implant of the balloon. A hypocaloric program was started after the second meal test. At hourly intervals, before and after the meal, patients were asked to rate the desire to eat, hunger, satiety and prospective consumption of food. After 2 months, weight loss was 12.0 +/- 5.1 kg. A significant decrease in the balloon diameters was observed, but none completely deflated. During the meal test performed 2-3 days after the implant, subjects rated themselves as significantly less hungry, fuller and desiring to eat less food. These patterns, however, returned to the baseline levels at the meal test performed after 2 months. No relationship was found between weight loss and reduction in the balloon diameters, nor between the latter and the changes in temporal profiles of eating ratings. The effect of a 500-ml balloon on meal-related hunger and satiety therefore seems to disappear with time.
    Amino acid catabolism and urea synthesis are increased in type 2 diabetes mellitus in poor metabolic control. In different catabolic conditions, prostaglandins (PGs) of the E series produced metabolic effects on nitrogen metabolism,... more
    Amino acid catabolism and urea synthesis are increased in type 2 diabetes mellitus in poor metabolic control. In different catabolic conditions, prostaglandins (PGs) of the E series produced metabolic effects on nitrogen metabolism, decreasing urea formation. In 10 patients with type 2 diabetes in poor metabolic control, urea synthesis and amino acid to urea nitrogen exchange were measured in the basal state and during an alanine load (6 hours) with 2-hour superinfusion of a PGE1 analog (30 microg/h) or saline in random order. The urea synthesis rate was calculated as the sum of urinary urea excretion and urea accumulation in total body water (TBW); total nitrogen exchange was calculated as the difference between infused amino acid-nitrogen and urea appearance. Plasma alpha-aminonitrogen (alpha-amino-N) increased 100% in response to alanine, to a steady-state without differences in relation to PG superinfusion. The urea synthesis rate (mean +/- SD) was 34.0 +/- 11.4 mmol/h in the basal period and increased to 161.2 +/- 37.0 during alanine + saline and to 113.5 +/- 34.6 during alanine + PG (P < .001). Nitrogen exchange was negative at baseline (-25.0 +/- 9.0 mmol/h). It became moderately positive during alanine + saline (14.6 +/- 25.1) and far more positive during alanine + PG (53.5 +/- 21.4), with the difference due to reduced urea formation. The metabolic effects of PG were not related to differences in insulin and glucagon. We conclude that PGE1 slows the high rate of hepatic urea-N synthesis in poorly controlled type 2 diabetes. Such metabolic effects have therapeutic implications.
    A comprehensive lifestyle approach is suggested as first-line treatment for the individual features of the metabolic syndrome, but the results in community medicine are usually discouraging. No study has tested the feasibility of an... more
    A comprehensive lifestyle approach is suggested as first-line treatment for the individual features of the metabolic syndrome, but the results in community medicine are usually discouraging. No study has tested the feasibility of an integrated approach between general practitioners (GPs) and specialist centers. We report the process analysis on baseline data of a randomized study based on the integration between GPs, selecting patients on the basis of a pre-defined grid and specific targets, and a specialist center, providing informative material and arranging courses of counseling and cognitive-behavioral therapy, using a shared database. After initial visits by GPs for clinical assessment and motivation to treatment, patients were randomly assigned to: (a) prescriptive diet, managed by GPs; (b) counseling (four group lessons); (c) cognitive-behavioral treatment (12 group lessons), both managed by specialist center. Data of the first 503 subjects were compared with those of 139 cases self-referring to the specialist center for the treatment of obesity. Subjects enrolled by GPs were more frequently males, had lower obesity grades, and a higher number of features of metabolic syndrome, compared with the control group. Only 10% of subjects randomized to counseling and 27% randomized to behavior declined participation in the intensive treatments; attendance at sessions averaged 90%. GPs were satisfied with their participation and reported that treatments met patients' needs. An integrated approach to lifestyle changes between GPs and a specialist center is feasible in the metabolic syndrome and may be cost-effective, considering the high burden of disease.
    The number of Na-K pump units, the Na-K-ATPase activity, the K transport turnover rate per pump unit and the intracellular Na and K concentrations were measured in the erythrocytes of 56 obese patients and 20 normal subjects. No... more
    The number of Na-K pump units, the Na-K-ATPase activity, the K transport turnover rate per pump unit and the intracellular Na and K concentrations were measured in the erythrocytes of 56 obese patients and 20 normal subjects. No differences were found between the two groups. In obese patients, we failed to observe any influence of dietary habits, age of onset, or family history of obesity on the Na pump status. On the other hand, we found that the number of pump units was not a close reflection of the membrane cation transport and in some patients with an abnormally high number of pump units, an inappropriately low Na-K-ATPase activity was observed. We also identified two small groups of obese patients with, respectively, abnormally high or low K transport turnover rate per pump unit. Our study seems to support the hypothesis that abnormalities in the erythrocyte Na-K pump system are not usual in the obese population but are probably present only in a limited number of selected patients.
    Amino acid catabolism and urea synthesis are increased in type 2 diabetes mellitus in poor metabolic control. In different catabolic conditions, prostaglandins (PGs) of the E series produced metabolic effects on nitrogen metabolism,... more
    Amino acid catabolism and urea synthesis are increased in type 2 diabetes mellitus in poor metabolic control. In different catabolic conditions, prostaglandins (PGs) of the E series produced metabolic effects on nitrogen metabolism, decreasing urea formation. In 10 patients with type 2 diabetes in poor metabolic control, urea synthesis and amino acid to urea nitrogen exchange were measured in the basal state and during an alanine load (6 hours) with 2-hour superinfusion of a PGE1 analog (30 microg/h) or saline in random order. The urea synthesis rate was calculated as the sum of urinary urea excretion and urea accumulation in total body water (TBW); total nitrogen exchange was calculated as the difference between infused amino acid-nitrogen and urea appearance. Plasma alpha-aminonitrogen (alpha-amino-N) increased 100% in response to alanine, to a steady-state without differences in relation to PG superinfusion. The urea synthesis rate (mean +/- SD) was 34.0 +/- 11.4 mmol/h in the basal period and increased to 161.2 +/- 37.0 during alanine + saline and to 113.5 +/- 34.6 during alanine + PG (P < .001). Nitrogen exchange was negative at baseline (-25.0 +/- 9.0 mmol/h). It became moderately positive during alanine + saline (14.6 +/- 25.1) and far more positive during alanine + PG (53.5 +/- 21.4), with the difference due to reduced urea formation. The metabolic effects of PG were not related to differences in insulin and glucagon. We conclude that PGE1 slows the high rate of hepatic urea-N synthesis in poorly controlled type 2 diabetes. Such metabolic effects have therapeutic implications.
    Obesity is the result of a complex interplay among several factors leading to medical, functional and psychosocial consequences that markedly reduce life expectancy and impair quality of life. Is obesity itself a disease? Is obesity a... more
    Obesity is the result of a complex interplay among several factors leading to medical, functional and psychosocial consequences that markedly reduce life expectancy and impair quality of life. Is obesity itself a disease? Is obesity a brain disease? Who should treat obesity? This paper is a narrative review aimed to describe and to argue the prevalent position of some major Italian scientific and academic institutions dealing with obesity. According to the recent statements and recommendations published by the Italian Society for Obesity (SIO) and the Italian Society for the Study of Eating Disorders (SISDCA), the management of obese patients should include five main levels of care: (1) primary care, (2) outpatient treatment, (3) intensive outpatient treatment, (4) residential rehabilitative treatment, and (5) hospitalization. Ideally, patients suffering from obesity need a multidimensional evaluation intended to design an individualized treatment plan applying different procedures and therapeutic strategies (diet, physical activity and functional rehabilitation, educational therapy, cognitive-behavior therapy, drug therapy, and bariatric surgery). This thorough approach should address not only weight loss but also quality of weight loss, medical and psychiatric comorbidity, psychosocial problems, and physical disability. Such management of obesity requires an effective multiprofessional team, while health services have to overcome a number of administrative and organizational barriers that do not account for diseases requiring resources and professionals from different areas of medicine. Integrating several competences in a team-based approach demands specific education, skills and expertise. As for other diseases, the principles of complexity theory may offer a model useful to implement both teamwork and care delivery for patients with obesity.