Cerebral saturation in cardiac arrest patients measured with near-infrared technology during pre-hospital advanced life support. Results from Copernicus I cohort study

AIM

To date, monitoring options during pre-hospital advanced life support (ALS) are limited. Regional cerebral saturation (rSO₂) may provide more information concerning the brain during ALS. We hypothesized that an increase in rSO₂ during ALS in out-of hospital cardiac arrest (OHCA) patients is associated with return of spontaneous circulation (ROSC).

METHODS

A prospective, non-randomized multicenter study was conducted in the pre-hospital setting of six hospitals in Belgium. Cerebral saturation was measured during pre-hospital ALS by a medical emergency team in OHCA patients. Cerebral saturation was continuously measured until ALS efforts were terminated or until the patient with sustained ROSC (>20 min) arrived at the emergency department. To take the longitudinal nature of the data into account, a linear mixed model was used. The correlation between the repeated measures of a patient was handled by means of ​a random intercept and a random slope. Our primary analysis tested the association of rSO₂ with ROSC.

RESULTS

Of the 329 patients 110 (33%) achieved ROSC. First measured rSO₂ was 30% ± 18 in the ROSC group and 24% ± 15 in the no-ROSC group (p = .004; mean ± SD). Higher mean rSO₂ values were observed in the ROSC group compared to the no-ROSC group (41% ± 13 versus 33% ± 13 respectively; p < 0.001). The median increase in rSO_2, measured from start until two minutes before ROSC, was higher in the ROSC group (ROSC group 17% (IQR 6-29)) than in the no-ROSC group (8% (IQR 2-13); p < 0.001). An increase in rSO₂ above 15% was associated with ROSC (OR 4.5; 95%CI 2.747-7.415; p < 0.001).

CONCLUSION

Regional cerebral saturation measurements can be used during pre-hospital ALS as an additional marker to predict ROSC. An increase of at least 15% in rSO₂ during ALS is associated with a higher probability of ROSC.

Predicting type 2 diabetes mellitus: a comparison between the FINDRISC score and the metabolic syndrome

BACKGROUND

The aim of this study to compare the diagnostic accuracy of the metabolic syndrome (MetS) with the FINDRISC score to screen for type 2 diabetes mellitus T2DM in an overweight/obese population.

METHODS

Subjects 18 years or older visiting the obesity clinic of the Antwerp University Hospital were consecutively recruited between 2012 and 2014. Every patient underwent a standard metabolic work-up including a clinical examination with anthropometry. Glucose status was tested using OGTT and Hba1c. FINDRISC questionnaire and MetS were examined.

RESULTS

Of 651 subjects, 50.4% were diagnosed with prediabetes, whereas 11.1% was diagnosed with T2DM. FINDRISC score increased with worsening of glucose status 11 ± 3, 13 ± 4 and 15 ± 5 in respectively, subjects without T2DM, prediabetes and T2DM. 312 subjects had the MetS. The aROC of the FINDRISC to identify subjects with T2DM was 0.76 (95% CI 0.72-0.82), sensitivity was 64% and specificity was 63% with 13 as cutoff point. Adding FPG or HbA1c to FINDRISC, the aROC increased significantly to 0.91(95% CI 0.88-0.95) and 0.93(95% CI 0.90-0.97), respectively (p < 0.001). The aROC of the MetS to identify subjects with diabetes was 0.72 (95% CI 0.65-0.78), sensitivity was 75% and specificity was 55%. The aROC of the FINDRISC + HbA1c was significantly higher than the MetS for predicting T2DM (p < 0.001).

CONCLUSION

Prediction of type 2 diabetes is important for timely intervention and to avoid chronic complications associated with the disease. Our findings suggest, that it may be of good clinical practice to use the FINDRISC score + HbA1c in a two-step screening model for diabetes rather than using the metabolic syndrome.

Inverse relationship between plasminogen activator inhibitor-1 activity and adiponectin in overweight and obese women

Adipose tissue is an active endocrine organ secreting different adipokines such as plasminogen activator inhibitor-1 (PAI-1) and adiponectin, among many others. In this study, we investigated the association between PAI-1 activity and serum adiponectin levels in a group of 444 overweight and obese women and assessed the interrelationship with visceral adipose tissue (VAT; CT-scan L4-L5), insulin resistance (HOMA-IR), HDL cholesterol (HDL-chol) and inflammation (hs-CRP). PAI-1 was inversely related to adiponectin (r=-0.25, p<0.001; adjusted for age and BMI).After adjustment for age, VAT, HOMA-IR and hs-CRP, the relationship remained significant (r=-0.15; p=0.001), but disappeared after additional adjustment for HDL-chol (r=-0.09; p=0.067). Subjects were divided in two groups according to the median levels of adiponectin or PAI-1 levels. PAI-1 activity (19.1±11.4 vs. 15.8±8.6 AU/ml; p=0.003) and adiponectin levels (9.8±4.6 vs. 8.4±4.0 μg/ml; p<0.001) were significantly higher in the low adiponectin/PAI-1 groups. The difference in PAI-1 remained significant after adjustment for age and BMI (p=0.001), became borderline significant after adjustment for age and VAT (p=0.052), and disappeared after adjustment for age and HOMA-IR (p=0.116) or age and HDL-chol (p=0.443).The difference in adiponectin levels remained significant after adjustment for age, VAT, HOMA-IR and hs-CRP (p=0.006), but disappeared after additional adjustment for HDL-chol (p=0.089). Further analyses suggest a contribution of HOMA-IR and/or HDL-chol in the relationship between PAI-1 and adiponectin. HDL-chol was found to be the only factor independently determining both factors. In conclusion, in overweight and obese women, PAI-1 activity was inversely related to serum adiponectin, independent of visceral adipose tissue.

Screening for type 2 diabetes mellitus in overweight and obese subjects made easy by the FINDRISC score

AIM

To evaluate the use of the FINDRISC score in an overweight and obese population to predict glucose status.

METHODS

In 651 overweight/obese subjects (M/F: 193/458, age 43±13 y, BMI 38.2±6.1kg/m(2)) glucose status was tested using OGTT and HbA1c. Furthermore, the FINDRISC questionnaire and CT visceral fat (VAT) and subcutaneous fat (SAT) were examined.

RESULTS

Exactly 50.4% were found to have prediabetes and 11.1% were newly diagnosed with type 2 diabetes (T2DM) (M/F=22.2/8.8%). Subjects without T2DM had a FINDRISC score of 11±3, those with pre-DM 13±4, and subjects with de novo T2DM 15±5. The aROC of the FINDRISC for detecting T2DM was 0.76 (95% CI 0.72-0.82), with 13 as cutoff point. The FINDRISC score correlated with VAT (r=0.34, p<0.001) and VAT/SAT ratio (r=0.39, p<0.001). The aROC of the FINDRISC to detect excess VAT was 0.79 (95%CI 0.72-0.84).

CONCLUSIONS

In a large group of overweight and obese subjects, 50.4% were found to have pre-DM and 11.1% were newly diagnosed with T2DM. The FINDRISC score increased with worsening of glucose tolerance status and proved to be an independent predictor of T2DM status, as did HOMA-B, HOMA-S and VAT. The FINDRISC can also function as a good tool to predict visceral obesity.

PPARα gene expression correlates with severity and histological treatment response in patients with non-alcoholic steatohepatitis

BACKGROUND & AIMS

Peroxisome proliferator-activated receptors (PPARs) have been implicated in non-alcoholic steatohepatitis (NASH) pathogenesis, mainly based on animal data. Gene expression data in NASH patients are scarce. We studied liver PPARα, β/δ, and γ expression in a large cohort of obese patients assessed for presence of NAFLD at baseline and 1 year follow-up.

METHODS

Patients presented to the obesity clinic underwent a hepatic work-up. If NAFLD was suspected, liver biopsy was performed. Gene expression was studied by mRNA quantification. Patients were reassessed after 1 year.

RESULTS

125 patients were consecutively included in the study, of which 85 patients had paired liver biopsy taken at 1 year of follow-up. Liver PPARα expression negatively correlated with the presence of NASH (p=0.001) and with severity of steatosis (p=0.003), ballooning (p=0.001), NASH activity score (p=0.008) and fibrosis (p=0.003). PPARα expression was positively correlated to adiponectin (R(2)=0.345, p=0.010) and inversely correlated to visceral fat (R(2)=-0.343, p<0.001), HOMA IR (R(2)=-0.411, p<0.001) and CK18 (R(2)=-0.233, p=0.012). Liver PPARβ/δ and PPARγ expression did not correlate with any histological feature nor with glucose metabolism or serum lipids. At 1 year, correlation of PPARα expression with liver histology was confirmed. In longitudinal analysis, an increase in expression of PPARα and its target genes was significantly associated with histological improvement (p=0.008).

CONCLUSION

Human liver PPARα gene expression negatively correlates with NASH severity, visceral adiposity and insulin resistance and positively with adiponectin. Histological improvement is associated with an increase in expression of PPARα and its target genes. These data might suggest that PPARα is a potential therapeutic target in NASH.

Prothrombotic factors in histologically proven nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

An independent role of nonalcoholic fatty liver disease (NAFLD) in the development of cardiovascular disease has been suggested, probably mediated through increased levels of prothrombotic factors. Therefore, we examined whether NAFLD is linked to a prothrombotic state, independently of metabolic risk factors in a large single-center cohort of overweight/obese patients. Patients presenting to the obesity clinic underwent a detailed metabolic and liver assessment, including an extensive panel of coagulation factors. If NAFLD was suspected, a liver biopsy was proposed. A series of 273 consecutive patients (65% female) with a liver biopsy were included (age, 44 ± 0.76 years; body mass index: 39.6 ± 0.40 kg/m(2)). Increase in fibrinogen, factor VIII, and von Willebrand factor and decrease in antithrombin III correlated with metabolic features, but not with liver histology. Levels of plasminogen activator inhibitor-1 (PAI-1) increased significantly with increasing severity of steatosis (P < 0.001), lobular inflammation (P < 0.001), ballooning (P = 0.002), and fibrosis (P < 0.001). Patients with nonalcoholic steatohepatitis had significantly higher PAI-1 values than those with normal liver (P < 0.001). In multiple regression, including anthropometric and metabolic parameters, steatosis remained an independent predictor of PAI-1 levels, explaining, together with fasting C-peptide and waist circumference, 21% of the variance in PAI-1. No consistent correlations with histology were found for the other coagulation factors.

CONCLUSION

In obesity, NAFLD severity independently contributes to the increase in PAI-1 levels, whereas other coagulation factors are unaltered. This finding might, in part, explain the increased cardiovascular risk associated with NAFLD.

Noninvasive assessment of nonalcoholic fatty liver disease in obese or overweight patients

BACKGROUND & AIMS

Reliable noninvasive tools are needed for staging nonalcoholic fatty liver disease (NAFLD). Published scoring systems have not been validated in prospective assessments of unselected patients. We aimed to identify factors that predicted development of nonalcoholic steatohepatitis (NASH) in a large group of overweight or obese patients and compared these with established factors.

METHODS

We performed a prospective analysis of factors associated with the development and severity of NAFLD in patients at a single obesity center. We evaluated liver involvement in 542 patients by a large set of routine and non-routine parameters, including ultrasound and genetic testing. Those suspected of having NAFLD underwent liver biopsy (57.7%). Patients were divided into design cohort (n = 200) and validation cohort (n = 113) to identify factors associated with the presence and severity of NAFLD and NASH.

RESULTS

Factors independently associated with development of NASH included increased levels of alanine aminotransferase (ALT), fasting levels of C-peptide, and ultrasound steatosis scores (USSs), with area under the receiver operating curve (AUROC) values of 0.854 in the design cohort and 0.823 in the validation cohort. NASH activity scores also correlated with level of ALT, USS, and fasting level of C-peptide (R(2) = 0.491). Independent predictors of advanced fibrosis included waist circumference and level of aspartate aminotransferase (AUROC values of 0.839 and 0.846 for design and validation cohorts, respectively; negative predictive values of 98% and 97%, respectively, for a cutoff of -2.14). Previously published scoring systems had significantly lower AUROC values. Levels of CK18 and PNPLA3 polymorphisms correlated with development of NASH but did not add value.

CONCLUSIONS

Parameters routinely analyzed in assessing obese patients can be used to determine the presence of NASH and advanced fibrosis. Non-routine tests do not increase diagnostic accuracy. Previously published scores are significantly less accurate.

Glucose intolerance and the amount of visceral adipose tissue contribute to an increase in circulating triglyceride concentrations in Caucasian obese females

Context

Lipotoxicity is a risk factor for developing obesity-related metabolic complications, including non-alcoholic fatty liver disease, type 2 diabetes (DM2), cardiovascular disease and stroke. Yet, the mechanisms underlying the development of lipotoxicity itself remain poorly understood. Here, we investigated whether glucose intolerance aggravates lipotoxicity by evaluating the association between triglyceride (TG) concentrations and glucose tolerance status in a cross-sectional study on obese Caucasian women at risk for DM2.

Methods

913 obese females unknown to have diabetes were recruited (mean age: 41.2±SD 12.3; median BMI: 36.2, IQR 32.9–40.2). Visceral (VAT) and subcutaneous abdominal adipose tissue volumes were quantified with computed tomography. Glucose, insulin, and triglyceride concentrations were determined in fasting state and following a 75 gram oral glucose tolerance test.

Results

Based on fasting and 2 h post-load glucose levels, 27% of the women had impaired glucose tolerance (IGT), and 8% had newly diagnosed DM2. Fasting TG concentrations were similar between the IGT- and DM2-groups, and increased as compared to women with normal glucose tolerance (NGT). Even when adjusting for age, hip circumference and VAT, fasting TG concentrations remained elevated as compared to NGT. Mixed modelling analysis of post-load responses showed that TG concentrations declined more slowly in the DM2-group as compared to IGT and NGT. However, when adjusting for VAT the difference in decline between the glucose tolerance groups disappeared.

Conclusions

Glucose intolerance associates with elevated fasting TG concentrations in obese Caucasian women. We propose that glucose intolerance and increased VAT reduce lipid disposal mechanisms and may accelerate lipotoxicity.

Full neurological recovery after extreme hypoglycemia during intensive insulin therapy: a case report

Since 2000, there has been an ongoing debate regarding tightness of glycemic control in critically ill patients. An increased risk of hypoglycemia is observed in patients treated with an intensive insulin protocol targeting "normoglycemia," probably accounting for a reduction of the overall benefit. Hypoglycemia is associated with neurological side effects and is found to be an independent predictor of mortality in most trials; however, long-term sequelae are rare if glucose is administered early. We describe a case of prolonged, extreme hypoglycemia in a critically ill patient treated according to an intensive insulin protocol who recovered without any neurological deficit at discharge.

Obesity and persistent organic pollutants: possible obesogenic effect of organochlorine pesticides and polychlorinated biphenyls

Persistent organic pollutants (POPs) are endocrine-disrupting chemicals associated with the development of the metabolic syndrome and type 2 diabetes. In humans, little is known about their role in the potential origin of obesity. This study aims to assess the associations between serum levels of POPs and the prevalence of obesity in a cohort of obese and lean adult men and women. POP serum samples were investigated cross-sectionally in 98 obese and 47 lean participants, aged ≥18 years. Serum samples were analyzed for the presence of polychlorinated biphenyl (PCB) congeners 153, 138, 180, and 170 and for the organochlorine pesticides, dichloro-diphenyl-dichloroethylene (pp-DDE), and β-hexachlorocyclohexane (βHCH). We established a significant negative correlation between BMI, waist, fat mass percentage, total and subcutaneous abdominal adipose tissue, and serum levels of PCB 153, 180, 170, and the sumPCBs. For βHCH, we demonstrated a positive correlation with BMI, waist, fat mass percentage, and total and subcutaneous abdominal adipose tissue. PCBs 180, 170, and the sum of PCBs correlated significantly negative with homeostasis model assessment for insulin resistance (HOMA(IR)). βHCH correlated significantly positively with HOMA(IR). A strong correlation was established between all POP serum levels and age. We established a positive relationship between high serum levels of βHCH and BMI and HOMA(IR), whereas serum PCB levels were inversely correlated with BMI and HOMA(IR). Combined, these results suggest that the diabetogenic effect of low-dose exposure to POPs might be more complicated than a simple obesogenic effect.

Transcriptional activation of apolipoprotein CIII expression by glucose may contribute to diabetic dyslipidemia

OBJECTIVE

Hypertriglyceridemia and fatty liver are common in patients with type 2 diabetes, but the factors connecting alterations in glucose metabolism with plasma and liver lipid metabolism remain unclear. Apolipoprotein CIII (apoCIII), a regulator of hepatic and plasma triglyceride metabolism, is elevated in type 2 diabetes. In this study, we analyzed whether apoCIII is affected by altered glucose metabolism.

METHODS AND RESULTS

Liver-specific insulin receptor-deficient mice display lower hepatic apoCIII mRNA levels than controls, suggesting that factors other than insulin regulate apoCIII in vivo. Glucose induces apoCIII transcription in primary rat hepatocytes and immortalized human hepatocytes via a mechanism involving the transcription factors carbohydrate response element-binding protein and hepatocyte nuclear factor-4α. ApoCIII induction by glucose is blunted by treatment with agonists of farnesoid X receptor and peroxisome proliferator-activated receptor-α but not liver X receptor, ie, nuclear receptors controlling triglyceride metabolism. Moreover, in obese humans, plasma apoCIII protein correlates more closely with plasma fasting glucose and glucose excursion after oral glucose load than with insulin.

CONCLUSIONS

Glucose induces apoCIII transcription, which may represent a mechanism linking hyperglycemia, hypertriglyceridemia, and cardiovascular disease in type 2 diabetes.

Visceral adiposity and insulin resistance are independent predictors of the presence of non-cirrhotic NAFLD-related portal hypertension

INTRODUCTION

We previously demonstrated in an animal model that steatosis, in the absence of fibrosis, induces a significant rise in portal pressure, indicating substantial changes in liver hemodynamics. As assessment of portal pressure is an invasive procedure, non-invasive parameters are needed to identify patients at risk.

AIMS

To study the portal pressure in nonalcoholic fatty liver disease patients and to identify factors that are possibly related to steatosis-induced changes in liver hemodynamics.

MATERIALS AND METHODS

Patients presenting with a problem of overweight or obesity, and in whom non-invasive investigations showed signs of liver involvement, were proposed for transjugular hepatic vein catheterization and liver biopsy. The biopsy was scored according to the Nonalcoholic Steatohepatitis Clinical Research Network Scoring System.

RESULTS

A total of 50 consecutive patients were studied. Their mean age was 47.9 ± 1.8 years; 31 (62%) were female. Hepatic venous pressure gradient was normal in 36 (72%) and elevated in 14 (28%) patients. The degree of steatosis was the only histological parameter that differed significantly between the two groups (P=0.016), and was a predictor of the presence of portal hypertension (PHT) in regression analysis (P=0.010). Comparing normal versus portal hypertensive patients, waist circumference (117 ± 2 versus 128 ± 4 cm, P=0.005), waist-hip ratio (0.96 ± 0.06 versus 1.04 ± 0.03, P=0.003), visceral fat (229 ± 15 versus 292 ± 35 cm(2), P=0.022), fasting insulin (15.4 ± 1.7 versus 21.8 ± 2.4 μU ml(-1), P=0.032), fasting c-peptide (1.22 ± 0.06 versus 1.49 ± 0.09 nmol l(-1), P=0.035) and homeostasis model assessment-insulin resistance (HOMA IR) (3.28 ± 0.29 versus 4.81 ± 0.57, P=0.019) were significantly higher. Age, gender, liver enzymes, ferritin and high-sensitive C-reactive protein were not significantly different. In regression analysis, waist circumference (P=0.008) and HOMA IR (P=0.043) were independent predictors of PHT.

CONCLUSIONS

Estimates of both visceral adiposity and IR are predictors for the presence of PHT, related to the degree of steatosis, and may help in identifying patients who are at risk of developing steatosis-related complications.

Visceral adipose tissue and inflammation correlate with elevated liver tests in a cohort of overweight and obese patients

OBJECTIVE

To study the relationship between elevated liver tests and high sensitive C-reactive protein (hs-CRP), as potential markers of liver inflammation and non-alcoholic steatohepatitis (NASH), with anthropometric and laboratory parameters in overweight patients, especially the relationship with visceral adipose tissue (VAT).

METHODS

Patients presenting to the obesity clinic were prospectively included. Detailed anthropometry, computed tomography (CT)-measured VAT, liver tests (aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT)) and hs-CRP were assessed, along with an extended series of biochemical parameters.

RESULTS

All 480 patients (gender distribution male (M)/female (F) (10/90%)) with complete data were included. Mean age was 39+/-13 years, mean BMI 34.5+/-6.0 kg m(-2). In 37.3% of the patients one or more of the liver tests were elevated. VAT was positively related to AST (r=0.18, P<0.001), ALT (r=0.29, P<0.001), ALP (r=0.16, P<0.01) and GGT (r=0.39, P<0.001). Comparing subjects with high (VAT>or=113 cm(2)) vs low (VAT<113 cm(2)) VAT levels, significant differences were noted for AST (26+/-12 vs 24+/-12 U l(-1), P=0.003), ALT (37+/-21 vs 31+/-21 U l(-1), P<0.001), ALP (76+/-20 vs 71+/-18 U l(-1), P=0.008), GGT (33+/-20 vs 25+/-15 U l(-1), P<0.001) and hs-CRP (0.62+/-0.43 vs 0.52+/-0.48 mg dl(-1), P<0.001). After correction for BMI the difference in AST and ALP between the high vs low VAT group disappeared. The differences for ALT and GGT remained significant (P=0.008 and P<0.001 respectively). After correction for hs-CRP the four different liver tests remained significantly higher in the high VAT group. A stepwise multiple regression analysis revealed that every single liver test has his own most important determinant; VAT and hs-CRP for AST, insulin resistance calculated with homeostasis model assessment (HOMA-IR) and hs-CRP for ALT and ALP, and triglycerides and VAT for GGT.

CONCLUSION

In overweight and obese patients, liver tests, especially ALT and GGT, are associated with visceral fat mass. After correction for BMI and hs-CRP, ALT and GGT are significantly higher in patients with increased VAT, thereby supporting evidence for a potential key role of VAT in the pathogenesis of non-alcoholic fatty liver disease (NAFLD).

Effect of long-term whole body vibration training on visceral adipose tissue: a preliminary report

AIM

To determine the effect of whole body vibration (WBV), combined with caloric restriction, on weight, body composition and metabolic risk factors in overweight and obese adults.

METHODS

A randomized, controlled study with a 6-month intervention period and a 6-month 'no intervention' follow-up. 61 of the 79 participants completed the study. Data were collected at baseline and at 3, 6 and 12 months in the control group (CONTROL), the diet only group (DIET), the diet plus fitness group (FITNESS) and the diet plus WBV group (VIBRATION).

RESULTS

Weight decreased significantly in all three intervention groups. Only FITNESS and VIBRATION managed to maintain a weight loss of 5% or more in the long term. Visceral adipose tissue (VAT) changed most in VIBRATION: -47.8 +/- 41.2 and -47.7 +/- 45.7 cm2 after 6 and 12 months respectively compared to CONTROL (-3.6 +/- 20.5 or +26.3 +/- 30.6 cm(2)), DIET (-24.3 +/- 29.8 or -7.5 +/- 28.3 cm(2)) and FITNESS (-17.6 +/- 36.6 or -1.6 +/- 33.3 cm(2)) (p < 0.001).

CONCLUSIONS

Combining aerobic exercise or WBV training with caloric restriction can help to achieve a sustained long-term weight loss of 5-10%. These preliminary data show that WBV training may have the potential to reduce VAT more than aerobic exercise in obese adults, possibly making it a meaningful addition to future weight loss programs.

Role of insulin as a negative regulator of plasma endocannabinoid levels in obese and nonobese subjects

OBJECTIVE

Endocannabinoids (ECs) control metabolism via cannabinoid receptors type 1 (CB1). Their plasma levels are elevated in overweight type 2 diabetes (T2D) and in obese patients, and decrease postprandially in normoweight individuals. We investigated in two different cohorts of nonobese or obese volunteers whether oral glucose in glucose tolerance tests (OGTT) or acute insulin infusion during euglycemic hyperinsulinemic clamp affect plasma EC levels.

DESIGN AND METHODS

OGTT was performed in ten obese hyperinsulinemic patients (body mass index (BMI)=35.8 kg/m2, fasting insulin=14.83 mU/l), and ten normoweight normoinsulinemic volunteers (BMI=21.9 kg/m2, fasting insulin=7.2 mU/l). Insulin clamp was performed in 19 mostly nonobese men (BMI=25.8 kg/m2) with varying degrees of liver fat and plasma triglycerides (TGs), with (n=7) or without T2D. Plasma levels of ECs (anandamide and 2-arachidonoylglycerol (2-AG)) were measured by liquid chromatography-mass spectrometry, before and 60 and 180 min after OGTT, and before and 240 and 480 min after insulin or saline infusion.

RESULTS

Oral glucose load decreased anandamide plasma levels to an extent inversely correlated with BMI, waist circumference, subcutaneous fat, fasting insulin and total glucose, and insulin areas under the curve during the OGTT, and nonsignificantly in obese volunteers. Insulin infusion decreased anandamide levels to an extent that weakly, but significantly, correlated negatively with TGs, liver fat and fasting insulin, and positively with high density lipoprotein cholesterol. OGTT decreased 2-AG levels to a lower extent and in a way weakly inversely correlated with fasting insulin.

CONCLUSIONS

We suggest that insulin reduces EC levels in a way inversely related to anthropometric and metabolic predictors of insulin resistance and dyslipidemia.

Possible role for ENPP1 polymorphism in obesity but not for INSIG2 and PLIN variants

Previous studies have suggested that ENPP1, INSIG2, and PLIN may be linked with a higher risk for obesity or with increased phenotypic measures of obesity. We selected polymorphisms in these candidate genes based on their prior associations with obesity risk or obesity parameters. K121Q (rs1044498) in ENPP1, rs7566605 in INSIG2, and rs894160 in PLIN were genotyped by Taqman assays in a Belgian sample of 1,078 obese subjects (body mass index (BMI) > 30 kg/m(2)) and 323 lean controls (18.5 < BMI < 25 kg/m(2)). BMI, waist circumference, and waist-to-hip ratio (WHR) were assessed by standard methods while a computerized tomography-scan was used to measure visceral (VFA), subcutaneous (SFA), and total (TFA) abdominal fat areas. Presence of the rare allele was not significantly different between cases and controls for the three variants that were tested, while only WHR was associated with ENPP1 in obese subjects. Our data thus indicate that K121Q, rs7566605, and rs894160 are not major contributing factors for obesity.

Association of the BDNF Val66Met variation with obesity in women

Brain-derived neurotrophic factor (BDNF) has been implied in the regulation of food intake. In the present study, we genotyped the Val66Met polymorphism in a Belgian cohort of 532 obese women and 197 healthy female controls and were, for the first time, able to show an association of the 66Met allele with obesity, at least in our female cohort.

Is there an increased incidence of surgically removed thyroid carcinoma in Belgium ten years after Chernobyl? A study of hospital discharge data

In order to provide some answers to the much debated subject of the consequences of the Chernobyl accident, this study attempts to measure the incidence of surgically removed thyroid cancers in Belgium ten years following the explosion. The analysis was made from the hospital discharge data between 1993 and 1998. It offers the advantage of national coverage in spite of certain validity limits. The results show an increase in surgically removed thyroid cancers, which is not, however, evident in the more susceptible younger generation who were involved at the time of the accident. Furthermore, the geographic distribution of the incidence is more marked in the south of the country, unaffected by the radioactive iodine contamination of 1986, which was more prevalent in the east of the country. The study of the type of surgery involved shows a rise in the proportion of total thyroidectomies. These findings are in favour of the hypothesis of a causal effect linking the increased incidence of thyroid cancers to medical practice and surgery in particular and not to the consequence of the possible contamination.

Overweight in adolescents: differences per type of education. Does one size fit all?

OBJECTIVE

To assess the lifestyle and prevalence of overweight among 16- to 18-year-old adolescents attending 4 different types of secondary education (SE).

DESIGN

Cross-sectional school-based survey.

PARTICIPANTS

A community sample of 994 adolescents (body mass index [BMI]: 15-43 kg/m2).

VARIABLES MEASURED

Overweight and obesity were assessed by BMI. Health-related quality of life (HRQL) was assessed using the 36-item short-form (SF-36) questionnaire. The Dutch eating behavior questionnaire was administered. Lifestyle was assessed using the Baecke questionnaire and self-reported activities.

ANALYSIS

Prevalence of overweight, HRQL and lifestyle were assessed per type of education. Gender differences and differences between BMI-categories were analyzed.

RESULTS

Students in Vocational SE were significantly more likely to be overweight (18%) or obese (7.5%) compared to students in other types of SE (chi square-27.0, P < .001). HRQL was significantly lower among obese girls compared to overweight (P = .009) or normal weight girls (P < .01). Obese and overweight adolescents scored higher in restrained eating than their normal weight peers (P < .001) but lower in externally induced eating (P = .001).

CONCLUSIONS AND IMPLICATIONS

Lifestyle and prevalence of overweight and obesity seems to differ between different types of education. This could be of importance when making health policy decisions. Health programs should focus on types of education with the highest prevalence of overweight and obesity and should be tailor-made to the specific needs of the targeted type of education.

PAI-1 activity, but not fibrinogen or von Willebrand factor, is inversely related to LDL particle size in type 2 diabetes

BACKGROUND

Levels of fibrinogen, von Willebrand factor (vWF) and plasminogen activator inhibitor-1 (PAI-1) have been associated with small low-density lipoprotein (LDL) particles. However, it is not clear whether these associations are independent of visceral adiposity or other components of the metabolic syndrome such as triglycerides or insulin resistance.

METHODS

Visceral adipose tissue (VAT; CT-scan), fibrinogen, von Willebrand factor antigen (vWF:Ag), PAI-1 activity and different metabolic parameters such as total cholesterol (chol), HDL-chol, triglycerides, insulin resistance (homeostasis model assessment; HOMA-IR) were determined in 41 women and 78 men with type 2 diabetes. LDL particle size was assessed by polyacrylamide gradient gel electrophoresis.

RESULTS

PAI-1 activity was inversely related to LDL particle size after adjustment for age and body mass index (BMI) (r=-0.28; p=0.006) or age and VAT (r=-0.26; p=0.01), but not after adjustment for age and HOMA-IR (r=-0.15; p=0.148) or age and triglycerides (r=-0.04; p=0.679). In multiple regression analysis, LDL particle size did not independently determine PAI-1 activity levels. Fibrinogen and vWF:Ag did not seem to be related to LDL size.

CONCLUSIONS

PAI-1 activity levels, in contrast to fibrinogen and vWF:Ag, seem to be related to the small LDL phenotype in patients with type 2 diabetes. However, this relationship was not independent of insulin resistance or triglycerides.

The G1422A variant of the cannabinoid receptor gene (CNR1) is associated with abdominal adiposity in obese men

Since recent data suggest that the endocannabinoid system controls food intake through central, and lipogenesis via peripheral CB1 receptors, we hypothesized that genetic variation at the cannabinoid receptor-1 (CNR1) locus could have an effect on adiposity. We investigated, whether a specific CNR1 G1422A genotype is associated with anthropometric markers of obesity and fat distribution in adult obese individuals. A total of 1,064 obese subjects (BMI > or = 30 kg/m2) without diabetes, impaired glucose tolerance or other endocrine diseases and 251 healthy control persons were genotyped for the G1422A variant (rs1049353) with a TaqMan assay. Anthropometric measures as body weight, BMI, waist and waist-to-hip ratio (WHR) were assessed by classical methods. Fat mass (FM) was measured by bio-impedance. The prevalence of the G1422A variant was not significantly different between cases and controls (OR = 1.056; P = 0.626). In obese women, no meaningful associations between CNR1 genotype and anthropometric parameters were found. In obese men, CNR1 1422 A/A genotype was significantly associated with higher WHR (P = 0.009) and waist circumference (P = 0.008) after adjusting for age and BMI. Fat mass percentage showed an association (P = 0.011) which disappeared after adjusting for age and BMI. A trend for an association was seen for fat mass (unadjusted P = 0.099; adjusted P = 0.033). Our data indicate that the G1422A polymorphism in the CNR1 gene is associated with increased abdominal adiposity in obese men.

Screening for melanocortin-4 receptor mutations in a cohort of Belgian morbidly obese adults and children

OBJECTIVE

To investigate whether pathogenic melanocortin-4 receptor (MC4R) mutations are a common cause of obesity in Belgium.

DESIGN

Cross-sectional mutation analysis.

SUBJECTS

In total, 95 morbidly obese adults (mean age 44.02+/-11.35 years; mean BMI 47.87+/-4.17 kg/m2 and 123 obese children and adolescents were screened for mutations in MC4R (mean age 16.56+/-2.58 years; BMI>95th percentile for age and sex; mean % overweight 170.86 +/- 23.63).

MEASUREMENTS

A series of anthropometric (e.g. weight, height, waist, hip), biochemical and clinical measurements were performed on all subjects. The entire coding region of MC4R was screened using DHPLC, a highly sensitive and specific method for mutation analysis. Direct sequencing was performed when the chromatogram deviated from the WT pattern.

RESULTS

Mutation screening of a cohort of Belgian obese adults and children did not detect any pathogenic mutations as only the previously described polymorphisms Val103Ile, Thr112Met and Ile251Leu were detected.

CONCLUSION

Pathogenic mutations in MC4R are not a common cause of obesity in a Belgian population of obese adults, children and adolescents.

Hemostasis and fibrinolysis in non-diabetic overweight and obese men and women. Is there still a role for leptin?

OBJECTIVE

Leptin has been associated with disturbances in hemostasis and fibrinolysis, with inconsistent results on the influence of fat mass. However, the influence of the amount of visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (SAT) has not yet been studied. In this study, we investigated the relationship between leptin and fibrinogen, von Willebrand factor antigen (vWF:Ag), and plasminogen-activator inhibitor-1 (PAI-1) activity and determined the influence of associated metabolic variables and VAT versus SAT.

METHODS

Fibrinogen, vWF:Ag, PAI-1,VAT and SAT (CT-scan), and insulin resistance (homeostasis model assessment; HOMA-IR) were measured in 199 women and 81 men with overweight or obesity visiting the weight management clinic of a university hospital.

RESULTS

Leptin did not relate to fibrinogen (r = 0.11 and 0.13 in women and men respectively; P > 0.05), a relationship with vWF:Ag was only found in men (r = 0.31; P = 0.005), while leptin related to PAI-1 activity in both men (r = 0.36; P < 0.001) and women (r = 0.23; P < 0.001). Further analysis showed leptin to have an effect on the variation of PAI-1 independent of VAT and HOMA-IR in women, but not in men. Multiple regression showed HOMA-IR to be the most important determinant of PAI-1, both in men and women, but leptin also showed an independent effect. As for vWF:Ag, leptin was an independent determinant in men only.

CONCLUSIONS

PAI-1 related to leptin levels independent of fat mass percentage, HOMA-IR, and the amount of VAT and SAT. For vWF:Ag this relationship was found only in men, and not in women, while a relationship with fibrinogen could not be demonstrated.

Characterization of an RFamide-related peptide orphan GPCR in C. elegans

We cloned and characterized an orphan FMRFamide-related peptide (FaRP) GPCR in Caenorhabditis elegans. We synthesized numerous structurally different FaRPs that were found in the C. elegans genome by bioinformatic analysis and used them to screen cells expressing the C26F1.6 receptor. Two peptides ending in M(orL)VRFamide elicited a calcium response in receptor-expressing mammalian Chinese hamster ovary cells. The response was dose-dependent and appeared to be very specific; that is, none of the other FaRPs were active, not even closely related peptides also ending in M(orL)VRFamide, which are encoded by the same peptide precursor. Pharmacological profiling with a truncated series of the most active peptide revealed that the full peptide sequence is necessary for receptor activation.

Is visceral adipose tissue a determinant of von Willebrand factor in overweight and obese premenopausal women?

Visceral obesity has been associated with an increased cardiovascular risk. However, the exact mechanisms are not completely clear. In this study we investigated the relationship between von Willebrand factor (vWF) and visceral adipose tissue (VAT) in a group of 181 overweight and obese premenopausal women visiting the weight management clinic of a university hospital. von Willebrand factor antigen (vWF:Ag), plasminogen activator inhibitor 1 (PAI-1) activity, VAT (computed tomography scan), insulin resistance (homeostasis model assessment of insulin resistance), and other anthropometric and metabolic parameters were measured. Subjects with VAT in the highest quintile had significantly higher levels of vWF:Ag (171+/-60 vs 129+/-40%; P=.001) and PAI-1 (24.7+/-8.5 vs 15.2+/-12.0 AU/mL; P<.001) compared with subjects in the lowest quintile. After correction for fat mass and homeostasis model assessment of insulin resistance the difference was still significant for vWF:Ag (P=.046), but not for PAI-1 (P>.05). Stepwise multiple regression analysis showed VAT and insulin resistance as independent determinants of vWF:Ag, whereas waist circumference, high-density lipoprotein cholesterol, and insulin resistance were independent determinants of PAI-1 activity. In a subgroup of 115 patients, we measured high-sensitivity C-reactive protein and found it to influence the relationship between VAT and vWF:Ag (r=0.16; P=.088), whereas the relationship with PAI-1 was still significant (r=0.21; P=.025). The results from this preliminary study suggest a plausible relation between visceral obesity and endothelial activation, possibly mediated by low-grade inflammation.

Among inflammation and coagulation markers, PAI-1 is a true component of the metabolic syndrome

OBJECTIVE

To investigate whether leukocyte count, fibrinogen, von Willebrand factor (vWF) and plasminogen activator inhibitor-1 activity (PAI-1) are increased in subjects with the metabolic syndrome as defined by the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) and the World Health Organisation (WHO).

DESIGN

Cross-sectional study.

SUBJECTS

A total of 520 overweight and obese subjects: 379 women and 141 men, visiting the weight management clinic of a University Hospital.

SUBJECTS AND MEASUREMENTS

Waist circumference, triglycerides, HDL cholesterol, blood pressure and fasting glucose were determined, and the presence or absence of the metabolic syndrome according to the NCEP-ATPIII criteria was assessed. In 349 subjects, data on the waist-to-hip ratio (WHR) and albumin excretion rate were available and the WHO criteria were applied. Insulin resistance was defined using the HOMA-IR index.

RESULTS

Subjects with the metabolic syndrome according to the NCEP-ATPIII criteria had significantly higher levels of leukocyte count (P < 0.001) and PAI-1 (P < 0.001), while no significant differences were found for fibrinogen or vWF (P > 0.05). Using the WHO criteria, similar results were found except for vWF, where higher levels were found in subjects with the metabolic syndrome. When subjects were classified according to the number of components of the metabolic syndrome, levels of leukocyte count, vWF and PAI-1 activity were significantly different (P < 0.05). In logistic regression analysis PAI-1, gender and leukocyte count were independent determinants of the metabolic syndrome (P < 0.001).

CONCLUSION

Evidence for being a true component of the metabolic syndrome is strong for PAI-1, less for leukocyte count and weak for vWF and fibrinogen.

Inverse relationship between plasminogen activator inhibitor-I activity and adiponectin in overweight and obese women. Interrelationship with visceral adipose tissue, insulin resistance, HDL-chol and inflammation

Adipose tissue is an active endocrine organ secreting different adipokines such as plasminogen activator inhibitor-1 (PAI-1) and adiponectin, among many others. In this study, we investigated the association between PAI-1 activity and serum adiponectin levels in a group of 444 overweight and obese women and assessed the interrelationship with visceral adipose tissue (VAT; CT-scan L4-L5), insulin resistance (HOMA-IR), HDL cholesterol (HDL-chol) and inflammation (hs-CRP). PAI-1 was inversely related to adiponectin (r = -0.25, p < 0.001; adjusted for age and BMI). After adjustment for age, VAT, HOMA-IR and hs-CRP, the relationship remained significant (r = -0.15; p = 0.001), but disappeared after additional adjustment for HDL-chol (r = -0.09; p = 0.067). Subjects were divided in two groups according to the median levels of adiponectin or PAI-1 levels. PAI-1 activity (19.1 +/- 11.4 vs. 15.8 +/- 8.6 AU/ml; p = 0.003) and adiponectin levels (9.8 +/- 4.6 vs. 8.4 +/- 4.0 microg/ml; p < 0.001) were significantly higher in the low adiponectin/PAI-1 groups. The difference in PAI-1 remained significant after adjustment for age and BMI (p = 0.001), became borderline significant after adjustment for age and VAT (p = 0.052), and disappeared after adjustment for age and HOMA-IR (p = 0.116) or age and HDL-chol (p = 0.443). The difference in adiponectin levels remained significant after adjustment for age, VAT, HOMA-IR and hs-CRP (p = 0.006), but disappeared after additional adjustment for HDL-chol (p = 0.089). Further analyses suggest a contribution of HOMA-IR and/or HDL-chol in the relationship between PAI-1 and adiponectin. HDL-chol was found to be the only factor independently determining both factors. In conclusion, in overweight and obese women, PAI-1 activity was inversely related to serum adiponectin, independent of visceral adipose tissue.

Opposite effects of insulin-like molecules and leptin in coronary heart disease of type 2 diabetes Preliminary data

INTRODUCTION

Leptin and insulin have been reported to be risk factors for coronary heart disease (CHD) in the general population, but their role in type 2 diabetes still remains unclear.

MATERIALS AND METHODS

The role of leptin and insulin upon CHD in type 2 diabetes was assessed in 154 patients, aged 31-77 years, who were treated with oral anti-diabetic agents. Multivariate logistic regression analyses were used with CHD (an established history of CHD or an abnormal treadmill test) as dependent, and leptin, insulin and potential confounders as independent variables.

RESULTS

Endogenous insulin was significantly associated with CHD in a model controlling for gender, age, duration of diabetes, body mass index, smoking and leptin (Odds ratio 1.45 per decile, 95% confidence interval 1.11-1.90). Improving control for confounding by replacing body mass index by subcutaneous fat (CT-measured at the L4-L5 level) and height in this model, resulted in a significant negative association between leptin and CHD (OR 0.60, 95% CI 0.37-0.96).

DISCUSSION

Leptin might have a beneficial effect on CHD in type 2 diabetes, probably by counteracting the effect of insulin-like molecules or insulin resistance. The effect was elucidated only after careful control for confounding by subcutaneous fat, the main source of leptin production.

Visceral fat as a determinant of fibrinolysis and hemostasis

An increased amount of deep abdominal visceral fat has generally been accepted as an important cardiovascular risk factor, and disturbances in hemostasis and fibrinolysis have been suggested to play a role. Fibrinogen and von Willebrand factor, representatives of the hemostatic system, and plasminogen activator inhibitor 1 (PAI-1), as the most important inhibitor of the fibrinolytic system, have been associated with visceral obesity, with the most convincing evidence found for the involvement of PAI-1. The association with fibrinogen and von Willebrand factor has been suggested to be merely a reflection of the association with inflammation and endothelial dysfunction. The fact that PAI-1 is secreted by adipose tissue has attracted much attention. The increase of PAI-1 in visceral obesity could be because visceral adipose tissue produces more PAI-1 compared with subcutaneous abdominal adipose tissue. The contribution of other cell types such as hepatocytes or endothelial cells is probably more important, with stimulation of PAI-1 production by different components of the metabolic syndrome. PAI-1 secretion by adipose tissue has been suggested to have a more local effect, playing a role in tissue remodeling during the development of obesity.

Leptin levels, leptin receptor gene polymorphisms, and energy metabolism in women

OBJECTIVE

Resting metabolic rate (RMR) is mainly determined by fat-free mass and additionally by age, sex, hormones, and possibly genetic differences. We evaluated whether leptin levels and polymorphisms in the leptin receptor (LEPR) gene were associated with energy expenditure phenotypes.

METHODS

RMR, body composition, and leptin levels were measured in 125 overweight and obese women. Three LEPR polymorphisms, Lys109Arg, Gln223Arg, and Lys656Asn, were typed on genomic DNA of another group of 192 women in whom RMR was measured. Fat, protein, and carbohydrate oxidation were calculated for 103 of these subjects. In 38 subjects, glucose-induced thermogenesis was measured over 3 hours.

RESULTS

In the first study group, a negative correlation between RMR and leptin levels was found after controlling for fat and fat-free mass. In multiple regression analysis, leptin contributed significantly to RMR, independent of body composition. In the second study group, RMR was not associated with LEPR polymorphisms. Differences in substrate oxidation rates were found among genotypes at the Lys656Asn site. In fasting conditions, Lys656Lys showed a trend to oxidize more carbohydrates and less fat than Asn656 carriers, a trend which became significant after the glucose load when carbohydrate oxidation rate in Lys656Lys was 15% higher than in Asn656 carriers (p = 0.04), and fat oxidation rate was 44% lower (p = 0.02).

DISCUSSION

These results suggest that DNA sequence variations in the LEPR gene could affect substrate oxidation. We hypothesize that this might be caused by differences in glucose levels, leading to differences in glucose oxidation rates.

Obesity, haemostasis and the fibrinolytic system

Obese patients are at risk for the development of cardiovascular diseases, which can in part be explained by disturbances in the haemostatic and fibrinolytic systems. Indeed, obese subjects tend to have higher values of fibrinogen, factor VII, factor VIII, von Willebrand factor and plasminogen activator inhibitor compared to non-obese subjects. Abdominal obesity, in particular, has been shown to be associated with disturbances in fibrinogen, factor VIII and von Willebrand factor, while less consistent results have been found for factor VII. Recently it has been demonstrated that the adipocyte itself is able to produce plasminogen activator inhibitor-1, possibly explaining the high levels found in obesity. Different studies have investigated the association between haemostatic and fibrinolytic parameters and the insulin resistance syndrome, often present in obese subjects. Fibrinogen has been found to be related to insulin, but it has been suggested that this relationship is not independent of the accompanying inflammatory reaction. Results from studies on the relationship between insulin resistance and factor VII, factor VIII and von Willebrand factor levels are inconsistent. In contrast, plasminogen activator inhibitor-1 has been found to correlate with all components of the insulin resistance syndrome, and can be considered as a true component of this metabolic syndrome. Weight loss seems to have a beneficial effect on factor VII--probably mediated through a reduction in triglycerides. Data on factor VIII and von Willebrand factor are scarce but weight loss does not seem to have an effect. Fibrinogen does not seem to be reduced by modest weight loss and a more substantial weight loss seems necessary to lower fibrinogen levels. In contrast, both modest and substantial weight loss have been found to significantly reduce plasminogen activator inhibitor-1 levels. In conclusion, the increased cardiovascular risk observed in obesity could in part be explained by the association between insulin resistance and components of the fibrinolytic and haemostatic systems. Whether this relationship is truly causal or indirect needs to be elucidated further.

Polymorphisms in the leptin receptor gene, body composition and fat distribution in overweight and obese women

OBJECTIVE

Leptin is an adipocyte-secreted hormone involved in body weight regulation, acting through the leptin receptor, localised centrally in the hypothalamus as well as peripherally, amongst others on adipose tissue. The aim of this study was to evaluate whether polymorphisms in the leptin receptor (LEPR) gene were related to obesity and body fat distribution phenotypes, such as waist and hip circumferences and the amount of visceral and subcutaneous fat.

METHODS

Three known LEPR polymorphisms, Lys109Arg, Gln223Arg and Lys656Asn, were typed on genomic DNA of 280 overweight and obese women (body mass index (BMI)>25), aged 18-60 y. General linear model (GLM) analyses were performed in 198 pre- and 82 postmenopausal women, adjusting the data for age and menopausal state, plus fat mass for the fat distribution phenotypes.

RESULTS

No associations were found between the LEPR polymorphisms and BMI or fat mass. In postmenopausal women, carriers of the Asn656 allele had increased hip circumference (P=0.03), total abdominal fat (P=0.03) and subcutaneous fat (P=0.04) measured by CT scan. Total abdominal fat was also higher in Gln223Gln homozygotes (P=0.04). Also in postmenopausal women, leptin levels were higher in Lys109Lys homozygotes (P=0.02).

CONCLUSION

In conclusion, polymorphisms in the leptin receptor gene are associated with levels of abdominal fat in postmenopausal overweight women. Since body fat distribution variables were adjusted for fat mass, these results suggest that DNA sequence variations in the leptin receptor gene play a role in fat topography and may be involved in the predisposition to abdominal obesity.

Visceral fat is a determinant of PAI-1 activity in diabetic and non-diabetic overweight and obese women

Plasminogen activator inhibitor type 1 (PAI-1), an inhibitor of fibrinolysis and an important and independent cardiovascular risk factor, has been shown to be elevated in obesity and type 2 diabetes. Recent study results have suggested that adipose tissue--visceral fat in particular--could play an important role in the fibrinolytic process.In order to assess the specific role of this fat distribution, we measured PAI-1 activity (AU/ml) and visceral fat (CT-scan at level L4-L5) in 2 groups of 30 overweight and obese diabetic and overweight and obese non-diabetic women. Subjects were matched for age, weight, body mass index, fat mass and total abdominal fat. Visceral adipose tissue and PAI-1 were significantly higher in diabetic women (p = 0.022 and p = 0.004 respectively) than in non-diabetic patients. Visceral fat correlated significantly with PAI-1 activity, even after correction for insulin and triglycerides (r = 0.28, p = 0.034). Stepwise regression analysis showed visceral fat as the most important determinant factor for PAI-1 in the whole group and in the non-diabetic group. In the diabetic group, fasting insulin was the most important determinant. These results show that visceral fat is more important than BMI or total body fat in the determination of PAI-1 levels. Furthermore, the increased amount of visceral fat in type 2 diabetics may contribute to the increase of PAI-1 activity levels and the subsequent increased risk for thrombovascular disease, regardless of BMI and total fatness.

Preparation and certification of a reference material on PCBs in pig fat and its application in quality control in monitoring laboratories during the Belgian "PCB-crisis"

In this article, the production and validation of a new certified reference material "PCBs in animal fat" for the control of the maximum level of 200 ng/g setup by the European Communities for veterinary products from Belgium is described. Three materials are established: a blank, one material with about 100 ng/g and one with about 200 ng/g (sum of seven PCBs). Data on the production and certification are given. Additionally, this material was used as an unknown test material in the quality assurance program of the Belgium meat monitoring system (before the certification of the material). While the certification was performed with an uncertainty of less than 10%, the round robin exhibited larger deviations. However, these deviations were less than 20% for most of the 30 participating laboratories. Only two had significantly higher deviations.

Leptin receptor gene polymorphisms are associated with insulin in obese women with impaired glucose tolerance

Leptin receptors are present on beta-cells as well as on muscle and fat cells, thus enabling leptin to modulate both insulin secretion and insulin action. Leptin inhibits especially the glucose-stimulated insulin secretion from pancreatic cells. The leptin receptor (LEPR) gene could thus play a role in the regulation of glucose and insulin after an oral glucose load. Therefore, the relationship between LEPR polymorphisms and glucose and insulin response to an oral glucose tolerance test (OGTT) was investigated. Three LEPR polymorphisms (Lys(109)Arg, Gln(223)Arg, and Lys(656)Asn) were typed on genomic DNA of 358 overweight and obese women, aged 18-60 yr. Based on an OGTT, 269 subjects were defined with normal glucose tolerance, and 89 with impaired glucose tolerance (IGT). Associations between genotypes and glucose metabolism were analyzed with a general linear models procedure in pre- and postmenopausal women separately, after adjusting the data for age and fat mass. In postmenopausal women with IGT (n = 24), associations were found with Lys(109)Arg and Lys(656)Asn for fasting insulin (P = 0.05) and with Lys(109)Arg and Gln(223)Arg for the insulin response to an OGTT (P < 0.02). In the same group, trends were found with Lys(656)Asn for fasting glucose as well as in response to the OGTT. In premenopausal women with IGT (n = 65), associations were found with Lys(109)Arg and Lys(656)Asn for overall glucose response to the glucose load. In contrast, no associations with insulin or glucose were found in women with normal glucose tolerance. In conclusion, these data indicate that LEPR polymorphisms are associated with insulin and glucose metabolism in women with impaired glucose homeostasis.

Reduction of the plasma concentration of C-reactive protein following nine months of endurance training

An intense physical exercise induces an inflammatory reaction as demonstrated by the delayed increase in blood of acute phase proteins and among them of C-reactive protein (CRP). There is also evidence for a diminished acute phase reaction due to regular exercise suggesting a suppression of the inflammatory response through training. With this background CRP was measured by a sensitive enzyme immunoassay under resting conditions before and after 9 months of training in 14 subjects preparing for a marathon with the aim of studying the effect of training on the base-line CRP concentration. The mean distance run per week increased significantly from 31 +/- 9 km at the beginning to 53 +/- 15 km after 8 months of training (p < 0.01). The aerobic capacity rose significantly after training as demonstrated by the increase of running velocity during a maximal treadmill test from 3.82 +/- 0.29 m/s pre-training to 4.17 +/- 0.17 m/s post-training at a blood lactate concentration of 4 mmol/L (p < 0.01). In 10 of 12 runners base-line CRP was diminished after training in spite of a continuous increase of training intensity. The CRP median fell from 1.19 mg/L before to 0.82 mg/L after training (p < 0.05). Since intense physical exercise is known to be associated with an inflammatory reaction of muscles and tendons, the CRP decrease was unexpected. In 2 subjects the CRP concentration rose markedly because of a borrelia infection and a knee injury, respectively. These values were caused by a pathological condition and were not considered for the statistical evaluation. In 10 non-training control subjects the CRP median did not change significantly during the same 9 months period. The decrease of the CRP base-line concentration after training suggests that intensive regular exercise has a systemic anti-inflammatory effect. This is of particular interest with regard to several recent reports confering on the concentration of CRP in plasma a predictive value for the risk of cardiac infarction, venous thrombosis or stroke.

Carbohydrate-induced thermogenesis in obese women. Effect of insulin and catecholamines

Results of studies on diet-induced thermogenesis in obese persons are contradictory. A number of factors have been postulated to mediate the obligatory and facultative component of thermogenesis. This study was designed to investigate some further factors mediating the carbohydrate-induced thermogenesis in obese women. In 13 obese women, thermogenic responses to glucose and fructose were compared and related to subsequent hormonal changes. The thermogenic effect after fructose ingestion was significantly (p<0.006) higher in comparison with glucose, despite lower values for both glucose and insulin concentrations. Carbohydrate oxidation was significantly higher after fructose (81+/-7 E% vs 62+/-10 E% p<0.01) while oxidation of fat was lower (10+/-9 E% vs 21+/-12 E% p<0.01). These effects may partly be due to the de novo lipogenesis and/or to changes in cellular metabolism. No clear relationship could be found between thermogenesis and the activity of the sympathetic nervous system, as expressed by urinary catecholamine levels. These results indicate that not insulin but the cellular rate of carbohydrate metabolism is responsible for the thermogenic response to different carbo-nutrients.

Are leptin levels dependent on body fat distribution in obese men and women?

Leptin levels are strongly related to total body fat. It is however not yet clear if leptin is also related to visceral fat accumulation or not. In this study, we investigated whether leptin is also associated with body fat distribution and if this association is different in men and women. Leptin was measured in 143 obese subjects (118 women and 25 men) with a body mass index (BMI) greater than 28. Also weight, skinfolds, waist-to-hip ratio (WHR), fat mass by bioimpedance analysis (BIA) were measured, and abdominal visceral and subcutaneous fat were determined by CT scan. Leptin levels were significantly related with BMI, with fat mass (in kg and percentage body fat) as measured by BIA and skinfolds, and with total abdominal fat mass and subcutaneous fat measured by CT scan. No association was found with visceral fat, waist circumference or WHR. In men and women separately, however, a correlation with visceral fat existed. After correction for total body fat, the correlation remained significant only with subcutaneous fat in women. Multiple regression analyses pointed out that percentage body fat was the most important determinant of leptin for all subjects, while for women subcutaneous fat was the most important parameter, and for men alone total abdominal fat. These results suggest that subcutaneous fat seems to be an important factor related to leptin levels.

A silver impregnation utilizing only reagent-grade chemicals for visualization of peripheral axons and fibroblasts

A silver impregnation procedure is described that enables the representation of numerous tissue components. It especially visualizes nerves and fibroblasts, which may be clearly distinguished from other tissue elements. Since it can be performed on thick sections, three-dimensional analysis of nerve terminations and fibroblasts in the tissues can be performed. The results are illustrated with the innervation of the rat snout and human labial sweat glands for nerves, and with bovine and pathological human material for fibroblasts. Axons are visualized as thin, sinuous black structures, sometimes, as in the case of autonomic efferents, with varicosities. Fibroblasts are revealed in their total extent by the darker staining of their nuclei and cytoplasm compared with that of the surrounding collagen. Cell processes can thus be followed for long distances, and may be seen to approach other cells. Previously published methods for the visualization of nerves and fibroblasts depended upon the use of commercial formalin, which is subject to the manufacturers' modifications. The method presented here uses exclusively analytical-grade reagents and distilled water. It is also less dependent than other methods on the fixation protocol.

Bacteraemia with Leptotrichia buccalis: report of a case and review of the literature

We report here on a new case of L. buccalis bacteraemia. To our knowledge 16 other cases of L. buccalis bacteraemia have been reported in the literature, most of them in neutropenic patients. However L buccalis endocarditis does occasionally occur in non-neutropenic patients. The identification of L. buccalis is based on well known phenotypic features and confirmed by the detection of a large peak of lactic acid by gas chromatography for non volatile organic acids. L. buccalis is sensitive to a wide range of antibiotics including beta-lactam antibiotics, but it is resistant to aminoglycosides and macrolides.

Gaze motor asymmetries in the perception of faces during a memory task

In 33 male and female adult volunteers, eye position recordings were performed by means of an infrared reflection technique. Slides of randomly shuffled black-and-white photographs (7.5 x 10 degrees) of faces and vases were projected for 6 or 20 sec respectively in a visual memory task. In each series, 10 slides of art nouveau vases and of the "inner part" of masked Caucasian faces were used. During recording the head was fixed by a bite-board. (a) For faces the preferred targets of the centre of gaze were the eyes, the mouth and nose region, for vases the contours and some prominent ornaments. (b) Left-right asymmetries in the gaze-movement sampling strategy appeared with faces, but not with vases. In faces, the overall time that the centre of gaze remained in the left half of the field of gaze was significantly longer than in the right half. (c) When, however, the amplitude of the gaze excursions into the left and right halves of the inspected items was taken as a measure and normalized, a preference for the right gaze field was observed. (d) The relative left-right bias during face inspection was stronger with the 6 sec than with the 20 sec inspection period and significantly stronger in female than in male subjects for the 6 sec tasks. (e) Left/right inversion of the face stimuli did not abolish the side bias. Thus the asymmetric sampling strategy when faces were inspected as compared to vases was due to "internal" factors on the part of the subjects. It is hypothesized that a left-right asymmetry in hemispheric visual data processing for face stimuli was the cause of a left-right asymmetry in gaze motor strategies when faces were inspected.