Our understanding of the mechanisms by which nonalcoholic fatty liver disease (NAFLD) progresses from simple steatosis to steatohepatitis (NASH) is still very limited. Despite the growing number of studies linking the disease with altered serum metabolite levels, an obstacle to the development of metabolome-based NAFLD predictors has been the lack of large cohort data from biopsy-proven patients matched for key metabolic features such as obesity. We studied 467 biopsied individuals with normal liver histology (n=90) or diagnosed with NAFLD (steatosis, n=246; NASH, n=131), randomly divided into estimation (80% of all patients) and validation (20% of all patients) groups. Qualitative determinations of 540 serum metabolite variables were performed using ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS). The metabolic profile was dependent on patient body-mass index (BMI), suggesting that the NAFLD pathogenesis mechanism may be quite different depending on an individual’s level of obesity. A BMI-stratified multivariate model based on the NAFLD serum metabolic profile was used to separate patients with and without NASH. The area under the receiver operating characteristic curve was 0.87 in the estimation and 0.85 in the validation group. The cutoff (0.54) corresponding to maximum average diagnostic accuracy (0.82) predicted NASH with a sensitivity of 0.71 and a specificity of 0.92 (negative/positive predictive values = 0.82/0.84).
The present data, indicating that a BMI-dependent serum metabolic profile may be able to reliably distinguish NASH from steatosis patients, have significant implications for the development of NASH biomarkers and potential novel targets for therapeutic intervention.
Metabolic alterations such as insulin resistance are thought to underlie the endothelial dysfunction and low grade inflammation found in morbid obesity. Twenty-six morbidly obese patients, aged 39.0 +/- 10.0 (mean +/- sd), were evaluated before and 4.2 +/- 0.8 months after bariatric surgery. A marked increment in the insulin sensitivity index (S(I)) and the endothelium-dependent vasodilatory response in a dorsal hand vein was observed after weight loss following bariatric surgery. Circulating levels of E-selectin, P-selectin, plasminogen activator inhibitor-1, and von Willebrand factor, which were higher than those in the control group, decreased significantly after surgery. Plasma vascular cell adhesion molecule-1, angiotensin-converting enzyme, intercellular adhesion molecule-1, thrombomodulin, and plasma and intraplatelet cGMP levels did not change after weight loss. All inflammatory markers were higher in morbidly obese patients. After surgery, C- reactive protein and sialic acid diminished, whereas circulating levels of IL-6, TNF-alpha, and its soluble receptors did not. Positive correlations were found between changes in adiposity and S(I) and changes in C-reactive protein and between changes in sialic acid and changes in endothelial function. In conclusion, a marked improvement in S(I), endothelial function, and low grade inflammation was observed in the weight-losing, morbidly obese patients after bariatric surgery. S(I) and adiposity appear to play roles in obesity-related, low grade inflammation that contribute to the endothelial dysfunction observed in morbid obesity.
Data on the long-term metabolic side-effects associated with antipsychotics are scarce. Prospective longitudinal studies in medication-naive patients with a first episode of psychosis are a valuable source of information as they provide an assessment prior to the antipsychotic exposure and minimize the effect of potential confounding factors. The aim of this study was to assess the course of weight gain and the incidence of metabolic abnormalities during the first 3 yr of antipsychotic treatment. Data were collected from a cohort of 170 first-episode psychosis patients. They were randomly assigned to haloperidol (32%); olanzapine (32%) and risperidone (36%). The dose used was flexible. The initial antipsychotic treatment was changed when required, based on clinical response and tolerability. The results showed that the mean weight gain at 3 yr was 12.1 kg (s.d. = 10.7). It appeared to increase rapidly during the first year (85% of the total mean weight gain) and then stabilized gradually over time. Total cholesterol, LDL-cholesterol and triglyceride levels followed a similar trajectory with a significant increase only during the first year. No significant changes were detected in the mean values of glycaemic parameters. Two patients with a family history of diabetes developed diabetes type II. At short-term the factors positively associated with weight gain were lower body mass index, male gender and olanzapine treatment. At long-term, functional status and clinical response were the main predictors. The results of our study indicate that the first year of antipsychotic treatment is a critical period for weight gain and metabolic changes. Identification of weight gain patterns may help to inform studies that aim to prevent or mitigate the metabolic adverse events associated with antipsychotic therapy.
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