Hypertriglyceridemia Results From an Impaired Catabolism of Triglyceride-Rich Lipoproteins in PLIN1-Related Lipodystrophy.

BACKGROUND: Pathogenic variants in PLIN1-encoding PLIN1 (perilipin-1) are responsible for an autosomal dominant form of familial partial lipodystrophy (FPL) associated with severe insulin resistance, hepatic steatosis, and important hypertriglyceridemia. This study aims to decipher the mechanisms of hypertriglyceridemia associated with PLIN1-related FPL. METHODS: We performed an in vivo lipoprotein kinetic study in 6 affected patients compared with 13 healthy controls and 8 patients with type 2 diabetes. Glucose and lipid parameters, including plasma LPL (lipoprotein lipase) mass, were measured. LPL mRNA and protein expression were evaluated in abdominal subcutaneous adipose tissue from patients with 5 PLIN1-mutated FPL and 3 controls. RESULTS: Patients with PLIN1-mutated FPL presented with decreased fat mass, insulin resistance, and diabetes (glycated hemoglobin A1c, 6.68±0.70% versus 7.48±1.63% in patients with type 2 diabetes; mean±SD; P=0.27). Their plasma triglycerides were higher (5.96±3.08 mmol/L) than in controls (0.76±0.27 mmol/L; P<0.0001) and patients with type 2 diabetes (2.94±1.46 mmol/L, P=0.006). Compared with controls, patients with PLIN1-related FPL had a significant reduction of the indirect fractional catabolic rate of VLDL (very-low-density lipoprotein)-apoB100 toward IDL (intermediate-density lipoprotein)/LDL (low-density lipoprotein; 1.79±1.38 versus 5.34±2.45 pool/d; P=0.003) and the indirect fractional catabolic rate of IDL-apoB100 toward LDL (2.14±1.44 versus 7.51±4.07 pool/d; P=0.005). VLDL-apoB100 production was not different between patients with PLIN1-related FPL and controls. Compared with patients with type 2 diabetes, patients with PLIN1-related FPL also showed a significant reduction of the catabolism of both VLDL-apoB100 (P=0.031) and IDL-apoB100 (P=0.031). Plasma LPL mass was significantly lower in patients with PLIN1-related FPL than in controls (21.03±10.08 versus 55.76±13.10 ng/mL; P<0.0001), although the LPL protein expression in adipose tissue was similar. VLDL-apoB100 and IDL-apoB100 indirect fractional catabolic rates were negatively correlated with plasma triglycerides and positively correlated with LPL mass. CONCLUSIONS: We show that hypertriglyceridemia associated with PLIN1-related FPL results from a marked decrease in the catabolism of triglyceride-rich lipoproteins (VLDL and IDL). This could be due to a pronounced reduction in LPL availability, related to the decreased adipose tissue mass.

Identification of a Gain-of-Function LIPC Variant as a Novel Cause of Familial Combined Hypocholesterolemia.

BACKGROUND: Atherosclerotic cardiovascular disease is the main cause of mortality worldwide and is strongly influenced by circulating low-density lipoprotein (LDL) cholesterol levels. Only a few genes causally related to plasma LDL cholesterol levels have been identified so far, and only 1 gene, ANGPTL3, has been causally related to combined hypocholesterolemia. Here, our aim was to elucidate the genetic origin of an unexplained combined hypocholesterolemia inherited in 4 generations of a French family. METHODS: Using next-generation sequencing, we identified a novel dominant rare variant in the LIPC gene, encoding for hepatic lipase, which cosegregates with the phenotype. We characterized the impact of this LIPC-E97G variant on circulating lipid and lipoprotein levels in family members using nuclear magnetic resonance-based lipoprotein profiling and lipidomics. To uncover the mechanisms underlying the combined hypocholesterolemia, we used protein homology modeling, measured triglyceride lipase and phospholipase activities in cell culture, and studied the phenotype of APOE*3.Leiden.CETP mice after LIPC-E97G overexpression. RESULTS: Family members carrying the LIPC-E97G variant had very low circulating levels of LDL cholesterol and high-density lipoprotein cholesterol, LDL particle numbers, and phospholipids. The lysophospholipids/phospholipids ratio was increased in plasma of LIPC-E97G carriers, suggestive of an increased lipolytic activity on phospholipids. In vitro and in vivo studies confirmed that the LIPC-E97G variant specifically increases the phospholipase activity of hepatic lipase through modification of an evolutionarily conserved motif that determines substrate access to the hepatic lipase catalytic site. Mice overexpressing human LIPC-E97G recapitulated the combined hypocholesterolemic phenotype of the family and demonstrated that the increased phospholipase activity promotes catabolism of triglyceride-rich lipoproteins by different extrahepatic tissues but not the liver. CONCLUSIONS: We identified and characterized a novel rare variant in the LIPC gene in a family who presents with dominant familial combined hypocholesterolemia. This gain-of-function variant makes LIPC the second identified gene, after ANGPTL3, causally involved in familial combined hypocholesterolemia. Our mechanistic data highlight the critical role of hepatic lipase phospholipase activity in LDL cholesterol homeostasis and suggest a new LDL clearance mechanism.

Plasma ceramides are associated with MRI-based liver fat content but not with noninvasive scores of liver fibrosis in patients with type 2 diabetes.

BACKGROUND: There is growing evidence that ceramides play a significant role in the onset and progression of non-alcoholic fatty liver disease (NAFLD), a highly prevalent condition in patients with type 2 diabetes associated with hepatic and cardiovascular events. However, the relationship between plasma ceramide levels and NAFLD severity in type 2 diabetes remains unclear. The main purpose of the present study was to investigate whether circulating levels of ceramides in patients with type 2 diabetes are associated with liver steatosis assessed by the highly accurate magnetic resonance imaging proton density fat fraction (MRI-PDFF). The secondary objective was to assess the relationship between plasma ceramides and noninvasive scores of liver fibrosis. METHODS: In this cross-sectional single-center study, plasma concentrations of 7 ceramides were measured by liquid chromatography-mass spectrometry in 255 patients with type 2 diabetes (GEPSAD cohort). Liver fat content was assessed by MRI-PDFF, and noninvasive scores of liver fibrosis (i.e. Fibrosis-4 index, NAFLD Fibrosis Score, FibroTest® and Fibrotic NASH Index) were calculated. A validation cohort of 80 patients with type 2 diabetes was also studied (LIRA-NAFLD cohort). RESULTS: Liver steatosis, defined as a liver fat content > 5.56%, was found in 62.4 and 82.5% of individuals with type 2 diabetes in the GEPSAD and LIRA-NAFLD cohorts, respectively. In GEPSAD, MRI-PDFF-measured liver fat content was positively associated with plasma levels of total ceramides (r = 0.232, p = 0.0002), and 18:0, 20:0, 22:0 and 24:0 ceramides in univariate analysis (p ≤ 0.0003 for all). In multivariate analysis, liver fat content remained significantly associated with total ceramides (p = 0.001), 18:0 (p = 0.006), 22:0 (p = 0.0009) and 24:0 ceramides (p = 0.0001) in GEPSAD, independently of age, diabetes duration, body mass index and dyslipidemia. Overall, similar relationship between plasma ceramides and liver fat content was observed in the LIRA-NAFLD validation cohort. No significant association was found between plasma ceramides and noninvasive scores of fibrosis after adjustment for age in both cohorts. CONCLUSIONS: Plasma ceramide levels are associated with liver steatosis in patients with type 2 diabetes, independently of traditional risk factors for NAFLD. The independent association between plasma ceramides and liver steatosis adds new insights regarding the relationship between ceramides and NAFLD in type 2 diabetes.

Liraglutide reduces plasma dihydroceramide levels in patients with type 2 diabetes.

BACKGROUND: Emerging evidence supports that dihydroceramides (DhCer) and ceramides (Cer) contribute to the pathophysiology of insulin resistance and liver steatosis, and that their circulating concentrations are independently associated with cardiovascular outcomes. Circulating DhCer levels are increased in patients with type 2 diabetes (T2D). On the other hand, the GLP-1 receptor agonist liraglutide reduces major adverse cardiac events, insulin resistance and liver steatosis in T2D patients. The main purpose of the present study was therefore to investigate whether liraglutide decreases circulating levels of DhCer and Cer in T2D patients, which could be a mechanism involved in its cardiometabolic benefits. The secondary purpose was to assess the relationship between liraglutide-induced changes in DhCer/Cer levels and insulin resistance and liver steatosis. METHODS: Plasma concentrations of 11 DhCer and 15 Cer species were measured by a highly-sensitive mass spectrometry system in 35 controls and 86 T2D patients before and after 6 months of liraglutide (1.2 mg/day). Insulin resistance was estimated by the triglyceride-glucose (TyG) index. Liver fat content (LFC) was assessed in 53 patients by proton magnetic resonance spectroscopy. RESULTS: Plasma levels of total DhCer, 7 DhCer and 7 Cer species were increased in T2D patients compared to controls. Liraglutide decreased total DhCer by 15.1% (p = 0.005), affecting 16:0 (p = 0.037), 18:0 (p < 0.0001), 18:1 (p = 0.0005), 20:0 (p = 0.0003), 23:0 (p = 0.005) and 24:1 (p = 0.04) species. Total plasma Cer did not significantly change after liraglutide (p = 0.18), but 5 Cer species decreased significantly, i.e. 18:0 and 18:1 (both p < 0.0001), 19:0 and 24:1 (both p < 0.01) and 26:1 (p = 0.04). In multivariate analysis, the reduction in DhCer after liraglutide was independently associated with the reduction in LFC (p = 0.0005) and in TyG index (p = 0.05). CONCLUSIONS: Liraglutide reduces plasma levels of numerous DhCer and Cer species in T2D patients, which may contribute to the cardiovascular benefit observed in the LEADER trial. The independent association between the decrease in plasma DhCer level with the reduction in LFC and TyG index adds new insights regarding the relationship between DhCer, liver steatosis and insulin resistance. Trial registration ClinicalTrials.gov identifier: NCT02721888.

HDL functionality in type 1 diabetes: enhancement of cholesterol efflux capacity in relationship with decreased HDL carbamylation after improvement of glycemic control.

BACKGROUND: Reduced cholesterol efflux capacity (CEC) of HDLs is likely to increase cardiovascular risk in type 1 diabetes (T1D). We aimed to assess whether improvement of glycemic control in T1D patients is associated with changes in CEC in relation with changes in carbamylation of HDLs. METHODS: In this open-label trial, 27 uncontrolled T1D patients were given a three-month standard medical intervention to improve glycemic control. HDL fraction was isolated from plasma, and CEC was measured on THP-1 macrophages. Carbamylation of HDLs was evaluated by an immunoassay. Control HDLs from healthy subjects were carbamylated in vitro with potassium cyanate. RESULTS: HbA1c decreased from 11.4% [10.2-12.9] (median [1st-3rd quartiles]) at baseline to 8.1% [6.6-9.0] after the three-month intervention (P < 0.00001). The CEC of HDLs increased after intervention in 19 (70%) patients (P = 0.038). At the same time, the carbamylation of HDLs decreased in 22 (82%) patients after intervention (P = 0.014). The increase in CEC significantly correlated with the decrease in carbamylated HDLs (r = -0.411, P = 0.034), even after adjustment for the change in HbA1c (ß = -0.527, P = 0.003). In vitro carbamylation of control HDLs decreased CEC by 13% (P = 0.041) and 23% (P = 0.021) using 1 and 10 mmol/L of potassium cyanate, respectively. CONCLUSIONS: The improvement of CEC in relation to a decrease in the carbamylation of HDLs may likely contribute to the beneficial cardiovascular effect of glycemic control in T1D patients. TRIAL REGISTRATION: NCT02816099 ClinicalTrials.gov.

Liraglutide Reduces Postprandial Hyperlipidemia by Increasing ApoB48 (Apolipoprotein B48) Catabolism and by Reducing ApoB48 Production in Patients With Type 2 Diabetes Mellitus.

Objective- Treatment with liraglutide, a GLP-1 (glucagon-like peptide-1) agonist, has been shown to reduce postprandial lipidemia, an important feature of diabetic dyslipidemia. However, the underlying mechanisms for this effect remain unknown. This prompted us to study the effect of liraglutide on the metabolism of ApoB48 (apolipoprotein B48). Approach and Results- We performed an in vivo kinetic study with stable isotopes (D8-valine) in the fed state in 10 patients with type 2 diabetes mellitus before treatment and 6 months after the initiation of treatment with liraglutide (1.2 mg/d). We also evaluated, in mice, the effect of a 1-week liraglutide treatment on postload triglycerides and analysed in vitro on jejunum, the direct effect of liraglutide on the expression of genes involved in the biosynthesis of chylomicron. In diabetic patients, liraglutide treatment induced a dramatic reduction of ApoB48 pool (65±38 versus 162±87 mg; P=0.005) because of a significant decrease in ApoB48 production rate (3.02±1.33 versus 6.14±4.27 mg kg-1 d-1; P=0.009) and a significant increase in ApoB48 fractional catabolic rate (5.12±1.35 versus 3.69±0.75 pool d-1; P=0.005). One-week treatment with liraglutide significantly reduced postload plasma triglycerides in mice and liraglutide, in vitro, reduced the expression of ApoB48, DGAT1 (diacylglycerol O-acyltransferase 1), and MTP (microsomal transfer protein) genes. Conclusions- We show that treatment with liraglutide induces a significant reduction of the ApoB48 pool because of both a reduction of ApoB48 production and an increase in ApoB48 catabolism. In vitro, liraglutide reduces the expression of genes involved in chylomicron synthesis. These effects might benefit cardiovascular health. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02721888.

Liver Fat Content in People with Pituitary Diseases: Influence of Serum IGF1 Levels.

Non-alcoholic fatty liver disease (NAFLD) is commonly associated with obesity, metabolic syndrome, and type 2 diabetes. NAFLD is also seen in patients with endocrinopathies. However, the relationship between endocrine diseases and the development of NAFLD is not well known. In this study, we set out to determine whether liver fat content (LFC) was associated with IGF1 levels in people with pituitary diseases (PD). Eighty-nine patients with pituitary diseases and 74 healthy controls were included in this study. LFC was measured using MRI. Hepatic steatosis was defined as LFC>5.5%. Patients with PD were older, and had a higher BMI than healthy controls. LFC was significantly higher in people with PD than in controls (6.5% vs. 3.2%; p<0.001). LFC was negatively associated with the IGF1 level. The prevalence of steatosis was higher in PD patients than in controls (36.3% vs. 14.8%; p=0.002). In multivariate analysis, which included patients and controls, the predictive variables for steatosis were age, BMI and IGF1 levels, whereas the presence of pituitary diseases and gender were not associated with steatosis. Our data showed that LFC was strongly associated with IGF1 levels. These results suggest that steatosis associated with PD is probably a consequence of a low IGF1 level in these patients.

Impairment of the Ability of HDL From Patients With Metabolic Syndrome but Without Diabetes Mellitus to Activate eNOS: Correction by S1P Enrichment.

OBJECTIVE: High-density lipoprotein (HDL) from nondiabetic patients with metabolic syndrome (MetS) displays abnormalities in their lipidome, such as triglyceride enrichment and sphingosine-1-phosphate depletion. We hypothesized that these abnormalities could impair the ability of HDL to stimulate endothelial nitric oxide synthase (eNOS). APPROACH AND RESULTS: Compared with HDL from control subjects, HDL from normoglycemic patients with MetS was 39% richer in triglycerides (P<0.01) and 15% poorer in sphingosine-1-phosphate (P<0.05; n=23 in each group). eNOS activity, assessed by the conversion of L-[3H]arginine to L-[3H]citrulline, was 69% lower in human umbilical vein endothelial cells incubated with HDL from MetS patients than in cells incubated with HDL from controls (P<0.0001). In addition, the activating phosphorylation of eNOS at serine (Ser) 1177 and of Akt (protein kinase B) at Ser473 was 37% (P<0.001) and 39% (P<0.05) lower, respectively, with HDL from MetS patients. Sphingosine-1-phosphate enrichment of HDL from MetS patients restored their ability to stimulate eNOS activity (P<0.05), in relation with a significant increase in eNOS phosphorylation at Ser1177 (P<0.05) and in Akt phosphorylation at Ser473 (P=0.05). By contrast, triglyceride enrichment of HDL from control subjects did not modify eNOS activity (P=0.90) and phosphorylation at Ser1177 (P=0.87). CONCLUSIONS: We provide evidence that the activation of eNOS by HDL is decreased in MetS patients before the appearance of diabetes mellitus and that sphingosine-1-phosphate depletion of HDL is the main factor responsible for this defect. This has important consequences on the impairment of HDL functionality and antiatherogenic properties in these patients.

Effects of Transcranial Magnetic Stimulation on the Hypothalamic-Pituitary Axis in Depression: Results of a Pilot Study.

Some studies have reported that repetitive transcranial magnetic stimulation (rTMS) applied to the dorsolateral prefrontal cortex (DLPFC) is able to induce changes in the hypothalamic-pituitary axis in subjects with major depression. The causes of these neuroendocrine effects are unknown and deserve to be studied. The authors monitored neuroendocrine hormones in 15 subjects with major depression treated by 1-Hz rTMS on the right DLPFC and explored a correlation with mood improvement. Unlike previous studies, no changes in serum cortisol, prolactin, and thyroid hormone levels were found. However, the authors did observe short-term changes in growth hormone levels in nonresponsive subjects.

Immunity, inflammation and reservoir in patients at an early stage of HIV infection on intermittent ART (ANRS 141 TIPI Trial).

OBJECTIVES: The objective of this study was to assess clinical and biological changes during intermittent ART (I-ART) started early, with significant time spent on versus off ART, which has never before been studied in ART-naive patients with high nadir and current CD4 cell count. PATIENTS AND METHODS: ART-naive HIV-1-infected patients with baseline CD4 ≥ 500/mm(3) and nadir CD4 ≥ 400/mm(3) received 2 years of I-ART (6 month periods on once-daily boosted-PI-based ART, alternating with 6 month periods without ART) in a 2 year, Phase II, non-comparative multicentre trial. The trial is registered with ClinicalTrials.gov, number NCT 00820118. RESULTS: The CD4 cell count remained ≥ 500/mm(3) at 2 years in all 44 patients included in the study. The mean 2 year count was higher than the mean count at baseline in 24 patients overall (55%; 95% CI 40%-69%) and in 20 (65%; 95% CI 48%-81%) of the 31 patients who fully adhered to the trial strategy. All but three of these latter patients had HIV-1 RNA concentrations below 50 copies/mL after each 6 month 'on' period. Only one strategy-related genotypic mutation (M184I) was detected. The HIV-1 DNA median load fluctuated, but it did not differ between month 0 and month 24 (2.8 versus 2.6 log10 copies/10(6) leucocytes, P = 0.29). Biomarkers of inflammation and endothelial activation remained stable between month 0 and month 24. Naive CD4, CD8+CCR5+ and CD8+CD38+ T cell numbers tended to decline. One patient developed Burkitt's lymphoma and 12 patients reported sexually transmitted infections. CONCLUSIONS: In patients with high nadir and current CD4 cell counts, 2 year I-ART maintained the CD4 cell count above 500/mm(3), with no increase in the viral reservoir. Immune activation seems related to HIV replication, while inflammation seems to evolve independently and require specific attention.

Apolipoprotein B is regulated by gonadotropins and constitutes a predictive biomarker of IVF outcomes.

BACKGROUND: Follicular fluid (FF) is an important micro-environment influencing oocyte growth, its development competence, and embryo viability. The FF content analysis allows to identify new relevant biomarkers, which could be predictive of in vitro fertilization (IVF) outcomes. Inside ovarian follicle, the amount of FF components from granulosa cells (GC) secretion, could be regulated by gonadotropins, which play a major role in follicle development. METHODS: This prospective study included 61 female undergoing IVF or Intra-cytoplasmic sperm injection (ICSI) procedure. Apolipoprotein B (APOB) concentrations in follicular fluid and APOB gene and protein expression in granulosa cells from reproductively aged women undergoing an in vitro fertilization program were measured. The statistical analyses were performed according to a quartile model based on the amount of APOB level found in FF. RESULTS: Amounts of APOB were detected in human FF samples (mean ± SD: 244.6 ± 185.9 ng/ml). The odds of obtaining an oocyte in the follicle and a fertilized oocyte increased significantly when APOB level in FF was higher than 112 ng/ml [i.e., including in Quartile Q 2, Q3 and Q4] (p = 0.001; p < 0.001, respectively). The probabilities of obtaining an embryo and a top quality embryo on day 2, were significantly higher if APOB levels were within the ranges of 112 and 330 ng/ml (i.e. in Q2 and Q3) or 112 and 230 ng/ml (i.e. in Q2), respectively (p < 0.001; p = 0.047, respectively). In addition, our experiments in vitro indicated that APOB gene and protein expression, along with APOB content into culture were significantly under-expressed in GC upon stimulation with gonadotropins (follicular stimulating hormone: FSH and/or human chorionic gonadotropin: hCG). CONCLUSION: We are reporting a positive and statistically significant associations between APOB and oocyte retrieval, oocyte fertilization, and embryo quality. Using an experimental study component, the authors report significant reduced APOB expression and content for luteinized granulosa cells cultured in the presence of gonadotropins.

Evolution of procalcitonin, C-reactive protein and fibrinogen levels in neutropenic leukaemia patients with invasive pulmonary aspergillosis or mucormycosis.

Unlike bacterial infections, the value of procalcitonin (PCT) in detecting fungal infections in leukaemia patients is not clear. To determine whether the monitoring of PCT coupled with C-reactive protein (CRP) and fibrinogen (Fib) could be helpful in the management of pulmonary aspergillosis (IPA) or mucormycosis (PM), we retrospectively analysed the evolution of PCT, CRP and Fib levels in 94 leukaemia patients with proven/probable IPA (n = 77) or PM (n = 17) from D-12 to D12 relative to IFI onset defined as D0. Overall, 2140 assays were performed. From D-12 to D0, 12%, 5% and 1.4% of patients had PCT >0.5, 1 and 1.5 µg l(-1) , respectively, while CRP was >50, 75 and 100 mg l(-1) in 84%, 70% and 57% and Fib was >4, 5 and 6 g l(-1) in 96%, 80% and 61% of cases respectively (P < 10(-7) ). The same trends were observed from D1 to D12. Overall, between D-12 and D12, only 6.4% of patients had PCT >1.5 µg l(-1) , while CRP >100 mg l(-1) and Fib >6 g l(-1) were observed in 80% and 75% of cases respectively (P < 10(-7) ). In leukaemia patients, IPA or PM was accompanied by a significant increase in CRP and Fib while PCT remained low.

Association between Admission Serum 25-Hydroxyvitamin D Levels and Functional Outcome of Thrombolyzed Stroke Patients.

BACKGROUND: 25-Hydroxyvitamin D (25(OH)D) deficiency is a frequent condition in patients who suffer a stroke, and several studies suggested that it may be associated with a poorer prognosis. The aim of this study was to investigate specifically the association between 25(OH)D levels and functional outcome at 3 months in ischemic stroke patients treated with intravenous thrombolysis. METHODS: Consecutive ischemic stroke patients who received intravenous thrombolysis were enrolled between 2010 and 2013. Baseline characteristics were collected, and serum concentrations of 25(OH)D were measured within the first 24 hours after admission and were analyzed according to the quartiles of their distribution (<25 nmol/L versus ≥ 25 nmol/L). Multivariable ordinal logistic regression was used to evaluate the association between 25(OH)D and 3-month functional outcome assessed by the modified Rankin score. RESULTS: Three hundred fifty-two patients were included (mean age 68.6 ± 15.8, 50.7% women, mean 25(OH)D level 45 ± 25 nmol/L). The characteristics of the patients only differed with regard to higher premorbid functional impairment in patients with low 25(OH)D. In univariate analysis, the risk of functional impairment in patients with low 25(OH)D levels was greater than that in patients with higher 25(OH)D levels (odds ratio [OR] 2.10, 95% confidence interval [CI]: 1.35-3.27, P = .001). This association was still observed after adjustment for confounding variables (OR 1.70, 95% CI: 1.06-2.71, P = .027). CONCLUSION: A low serum 25(OH)D level is associated with worse functional outcome in patients with acute ischemic stroke treated with intravenous thrombolysis. Further investigations are required to understand the underlying mechanisms of this association.

Oxidation-induced loss of the ability of HDL to counteract the inhibitory effect of oxidized LDL on vasorelaxation.

Several current diseases are associated with an increase in the oxidation of HDL, which is likely to impair their functionality. Our aim was to identify whether oxidation could change the protective effect of HDL against the deleterious effect on vasoreactivity induced by oxidative stress. HDL from healthy subjects were oxidized in vitro by Cu(2+), and the ability of oxidized HDL to counteract the inhibitory effect of oxidized LDL on acetylcholine-induced vasodilation was tested on isolated rabbit aorta rings. Oxidation of HDL was evidenced by the increase in the 7-oxysterols/cholesterol ratio (3.20 ± 1.12 vs 0.02 ± 0.01 % in native HDL, p < 0.05). Oxidized LDL inhibited endothelium-dependent vasodilation (E max = 50.2 ± 5.0 vs 92.5 ± 1.7 % for incubation in Kreb's buffer, p < 0.05) and native HDL counteracted this inhibition (E max = 72.4 ± 4.8 vs 50.2 ± 5.0 % p < 0.05). At the opposite, oxidized HDL had no effect on oxidized LDL-induced inhibition on endothelium-dependent vasorelaxation (E max = 53.7 ± 4.8 vs 50.2 ± 5.0 %, NS). HDL oxidation is associated with a decreased ability of HDL to remove 7-oxysterols from oxidized LDL. In conclusion, these results show that oxidation of HDL induces the loss of their protective effect against endothelial dysfunction, which could promote atherosclerosis in diseases associated with increased oxidative stress.

Circulating apelin is increased in patients with type 1 or type 2 diabetes and is associated with better glycaemic control.

CONTEXT: Apelin is an adipokine expressed in several tissues and it appears to be involved in energy metabolism. OBJECTIVE: The aim of this study was to determine serum apelin levels in a large cohort of patients with type 1 and type 2 diabetes and control subjects and to correlate the results with glycaemic control. DESIGN AND PARTICIPANTS: One hundred and thirty patients with type 1 diabetes, 98 patients with type 2 diabetes and 162 controls were enrolled in the study. Apelin levels were measured by enzyme-linked immunosorbent assay. RESULTS: Serum apelin levels were significantly higher in type 1 and type 2 diabetic patients than in controls (P < 0·0001). Serum apelin levels were higher in type 1 than in type 2 diabetic patients (P = 0·02). In multivariate analysis, serum apelin levels were higher in patients with type 1 diabetes and in patients with type 2 diabetes versus controls. We found a negative correlation between glycosylated haemoglobin and serum apelin levels in all diabetic patients (r = -0·17, P = 0·008) and in patients with type 2 diabetes (r = -0·24 P = 0·01). No correlation was found in type 1 diabetic patients. CONCLUSION: Our study showed that apelin concentrations were increased in diabetic patients. This rise, which was greater in type 1 than in type 2 diabetic patients, suggests that obesity is not the main determinant of plasma apelin levels. The negative correlation with glycosylated haemoglobin in patients with type 2 diabetes could indicate that apelin plays a role in glycaemic balance and even insulin sensitivity.

A case-control study of pre-operative levels of serum neutrophil gelatinase-associated lipocalin and other potential inflammatory markers in colorectal cancer.

BACKGROUND: Chronic inflammation is a key feature of colorectal cancer (CRC), meaning that inflammatory biomarkers may be useful for its diagnosis. In particular, high neutrophil gelatinase-associated lipocalin (NGAL) expression has been reported in CRC. Thus, we investigated whether serum NGAL and NGAL/MMP-9 could be potential biomarkers for the early detection of CRC. Concurrently, we studied other inflammatory biomarkers such as soluble tumor necrosis factor receptor 1 and 2 (sTNFR-1, sTNFR-2), and C reactive protein (CRP). METHODS: The AGARIC multicenter case-control study was performed in eastern France and included patients admitted for elective surgery either for a priori non-metastatic incident CRC (n=224) or for benign causes (n=252). Pre-operative serum levels of NGAL, NGAL/MMP-9, sTNFR-1, sTNFR-2 and CRP were measured. RESULTS: Median values of serum NGAL, NGAL/MMP-9, sTNFR-1, sTNFR-2 and CRP were significantly higher in CRC patients than in controls. Receiver Operating Characteristic analysis provided relatively poor values of area under the curve, ranging from 0.65 to 0.58. Except for NGAL/MMP-9, all biological parameters were strongly correlated in CRC cases and, less strongly in controls. Multivariate odds ratio (OR) of CRC comparing the extreme tertiles of serum NGAL was 2.76 (95% confidence interval (CI): 1.59-4.78; p<0.001),. Lower but significant multivariate associations were observed for sTNFR-1, and sTNFR-2: OR=2.44 (95% CI : 1.34-4.45, p=0.015) and 1.93 (95% : CI 1.12-3.31), respectively. No independent association was found between case-control status and NGAL/MMP-9. Among CRC cases, maximal tumor size was an independent determinant of serum NGAL (p=0.028) but this association was reduced after adjustment for CRP (p=0.11). CONCLUSION: Despite a significant increase in serum NGAL and other inflammatory markers among CRC patients, our findings suggest that they may not be suitable biomarkers for the diagnosis and especially early detection of CRC.

Chronic hyperinsulinemia does not increase the production rate of high-density lipoprotein apolipoprotein AI: evidence from a kinetic study in patients with insulinoma.

OBJECTIVE: In vitro studies showed that insulin stimulates the production of apolipoprotein AI (apoAI). Thus, we hypothesized that chronic hyperinsulinemia could contribute to the increase in the production of high-density lipoprotein apoAI that is observed in metabolic syndrome. APPROACH AND RESULTS: We performed an in vivo kinetic study with stable isotope in 7 patients with insulinoma who showed hyperinsulinemia but no insulin resistance, 8 patients with insulin resistance, and 16 controls. Insulinemia was 3.1× (P<0.01) higher in patients with insulinoma or insulin resistance than in controls in the fasting state and, respectively, 3.5× and 2.6× (P<0.05) higher in the fed state. The high-density lipoprotein apoAI pool size was smaller in patients with insulin resistance than in controls (49.3 ± 5.4 versus 59.6 ± 7.7 mg · kg(-1); P<0.01), whereas both the high-density lipoprotein apoAI fractional catabolic rate and the high-density lipoprotein apoAI production rate were higher (0.30 ± 0.07 versus 0.20 ± 0.04 pool · d(-1); P<0.0001 and 14.6 ± 1.5 versus 11.5 ± 1.9 mg · kg(-1) · d(-1); P<0.01, respectively). In contrast, no significant difference was observed for these parameters between patients with insulinoma and controls. In patients with insulinoma, the apoAI pool size tended to be greater than in patients with insulin resistance (56.3 ± 8.6 versus 49.3 ± 5.4 mg · kg(-1); P=0.078), whereas both the apoAI fractional catabolic rate and the production rate were lower (0.20 ± 0.06 versus 0.30 ± 0.07 pool · d(-1); P<0.01 and 11.1 ± 1.6 versus 14.6 ± 1.5 mg·kg(-1) · d(-1); P<0.01, respectively). The apoAI fractional catabolic rate was the only variable associated with the apoAI production rate in multivariate analysis and explained 80% of its variance. CONCLUSIONS: Chronic endogenous hyperinsulinemia does not induce any increase in the apoAI production rate, which seems to be more dependent on the apoAI fractional catabolic rate.

Preoperative adipocytokines as a predictor of surgical infection after colorectal surgery: a prospective survey.

BACKGROUND: Infections are the leading cause of morbidity and mortality after colorectal surgery. Obesity is a well-known risk factor for wound infection, but it does not seem to increase the risk of other infectious complications. The aim of this study was to look for a relationship between the fatty tissue metabolism measured by adipocytokine levels and the risk of postoperative infection. PATIENTS AND METHODS: Preoperative plasma levels of eight adipocytokines, cholesterol, triglycerides, insulin and C-reactive protein (CRP) were measured in consecutive patients undergoing elective colorectal surgery between June 2008 and June 2011. Information about epidemiological and clinical characteristics was obtained for each patient. All infections in the 30 days following surgery were recorded. RESULTS: Among the 174 patients included, 49 (28 %) presented with a postoperative infection: 41 surgical site infections and 8 other infections. Preoperative leptin, insulin and CRP were significantly higher in patients with postoperative infection (p = 0.025, p = 0.020 and p = 0.044, respectively), but only leptin was predictive of infection in multivariate analysis (odds ratio (OR) = 1.89, 95 % confidence interval (CI) 1.18-3.03, p = 0.008). The predictive value of leptin was slightly lower for surgical site infection (OR = 1.65, 95 % CI 1.06-2.55, p = 0.025). Leptin levels were independent of the other adipocytokine levels but not of the body mass index. CONCLUSION: Although markers of inflammation and insulin resistance are also related to the onset of surgical infection, leptin correlates more closely with the risk of infection than does any other factor. However, its effect could be partially mediated by the body mass index.

No effect of liraglutide on high density lipoprotein apolipoprotein AI kinetics in patients with type 2 diabetes.

AIM: The catabolism of high density lipoprotein (HDL) apolipoprotein AI (apoAI) is accelerated in patients with type 2 diabetes (T2D), related to hypertriglyceridemia, insulin resistance and low plasma adiponectin levels. Since liraglutide is likely to partly correct these abnormalities, we hypothesized that it might have a beneficial effect on HDL apoAI kinetics in patients with T2D. METHODS: An in vivo kinetic study of HDL apoAI was performed in 10 patients with T2D before and after 6 months of treatment with 1.2 mg/day of liraglutide, using a bolus of l-[1-13C]leucine followed by a 16-hour constant infusion. RESULTS: Liraglutide reduced BMI (34.9 ± 4.7 vs 36.6 ± 4.9 kg/m2, P = 0.012), HbA1c (7.1 ± 1.1 vs 9.6 ± 2.6%, P = 0.003), HOMA-IR (5.5 ± 1.9 vs 11.6 ± 11.2, P = 0.003), fasting triglycerides (1.76 ± 0.37 vs 2.48 ± 0.69 mmol/l, P < 0.001) and triglycerides during kinetics (2.34 ± 0.81 vs 2.66 ± 0.65 mmol/l, P = 0.053). Plasma HDL cholesterol and adiponectin concentrations were unchanged (respectively 0.97 ± 0.26 vs 0.97 ± 0.19 mmol/l, P = 1; 3169 ± 1561 vs 2618 ± 1651 µg/l, P = 0.160), similar to triglyceride content in HDL (5.13 ± 1.73 vs 5.39 ± 1.07%, P = 0.386). Liraglutide modified neither HDL apoAI fractional catabolic rate (0.35 ± 0.11 vs 0.38 ± 0.11 pool/day, P = 0.375), nor its production rate (0.44 ± 0.13 vs 0.49 ± 0.15 g/l/day, P = 0.375), nor its plasma concentration (1.26 ± 0.19 vs 1.29 ± 0.14 g/l, P = 0.386). CONCLUSION: Six months of treatment with 1.2 mg/day of liraglutide had no effect on the kinetics of HDL apoAI in patients with T2D. The lack of decrease in triglyceride content in HDL related to an only moderate decrease in triglyceridemia, probably greatly explains these results. Insufficient improvement of insulin sensitivity and adiponectinemia may also be implied.

Plasma 16:0 ceramide as a marker of cardiovascular risk estimated by carotid intima-media thickness in people with type 2 diabetes.

AIM: New tools are required to better assess cardiovascular risk in individuals with type 2 diabetes mellitus (T2DM). Plasma ceramides emerge as promising candidates, given their substantial influence on the pathogenesis of both T2DM and atherosclerosis. The current study aimed to investigate whether plasma ceramides in patients with T2DM are a predictive factor for carotid intima-media thickness (CIMT), a well-established noninvasive marker for atherosclerosis that predicts adverse cardiovascular outcomes. METHODS: A lipidomic analysis was carried out on the circulating ceramides of a large cohort consisting of 246 patients with T2DM who underwent a high-resolution real-time B ultrasonography to measure CIMT. RESULTS: Both plasma 16:0 ceramide and the 16:0/24:0 ceramide ratio were positively associated with CIMT, even after adjustment for traditional cardiovascular risk factors [standardized ß ± standard error: 0.168 ± 0.072 (P = 0.020) and 0.180 ± 0.068 (P = 0.009), respectively]. Similar independent associations were found with respect to the prediction of CIMT ≥ 0.80 mm [ß = 8.07 ± 3.90 (P = 0.038) and 16.5 ± 7.0 (P = 0.019), respectively]. The goodness-of-fit for multivariate models in predicting CIMT was 5.7 and 7.6 times higher when plasma 16:0 ceramide or the 16:0/24:0 ceramide ratio were included in combination with traditional cardiovascular risk factors (P = 0.020 and 0.015, respectively). This reached a 3.1 and 10.0-fold increase regarding the ability to predict CIMT ≥ 0.80 mm (P = 0.039 and 0.008, respectively). CONCLUSIONS: Our findings suggest that 16:0 ceramide and the 16:0/24:0 ceramide ratio may serve as plasma biomarkers to improve cardiovascular risk assessment in individuals with T2DM.