Angiopoietin-like protein 4: development, analytical characterization, and clinical testing of a new ELISA

The aim of our work was to develop an assay for the determination of angiopoietin-like protein 4 (Angplt4) in human blood, and to investigate its levels in healthy volunteers and donors suffer from metabolic syndrome. We developed and evaluated the sandwich ELISA method for the quantitative determination of human Angplt4 in serum samples. We conducted also the pilot study on individuals with metabolic syndrome or familiar hypercholesterolemia and healthy probands and measured blood pressure, waist circumference, Angplt4 serum levels, serum cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, insulin, glucose, A-FABP and calculate BMI and QUICKI insulin sensitivity index. In the study on 30 healthy volunteers we demonstrated that sex or age is not the determinant for Angplt4 serum values. Furthermore, we tested 115 individuals with metabolic syndrome and found that probands with metabolic syndrome did not differ in Angplt4 values than healthy individuals from the first study (medians 8.7 vs. 8.1 ng/ml, p = 0.6). Individuals with metabolic syndrome did not differ in sex or age from healthy. Angplt4 values correlated with the HDL-cholesterol (r = -0.25; p < 0.01), FGF-21 (r = 0.23, p < 0.01), glucose (r = 0.17; p = 0.03), uric acid (r = 0.17; p = 0.49), lipocalin-2 (r = 0.23, p < 0.01), triacylglycerols (r = 0.25; p < 0.01) and number or characters of metabolic syndrome (r = 0.21; p < 0.01). No significant correlation was found between serum Angplt4 and BMI, WC or QUICKI. However, we performed stepwise regression and we found that Angplt4 was not an independent marker for metabolic syndrome. The patients from the metabolic syndrome group suffering diabetes mellitus (n = 83) did not differ in serum Angplt4 from the group of healthy patients, too. The pilot study supports the hypothesis about the role of Angplt4 as a new class of lipid metabolism modulator. Their values could be a new key predictors of metabolic syndrome. Further research is necessary to confirm our findings in individuals with dyslipidemia, obesity, coronary artery diseases and different medication in order to assess Angplt4 value as a risk predictor of accelerated atherosclerosis.     

Lipocalin-2: development, analytical characterization, and clinical testing of a new ELISA.

Lipocalin-2 (also known as neutrophil gelatinase-associated lipocalin [NGAL]) has been described as a promising marker of metabolic syndrome associated with inflammation. The aim of our work was to develop an assay for the determination of lipocalin-2 in human serum and to investigate its levels in healthy volunteers and donors suffering from metabolic syndrome. We also conducted a pilot study on individuals with metabolic syndrome and on healthy probands and measured lipocalin-2 in these individuals. We developed and evaluated the sandwich ELISA method for the quantitative determination of human lipocalin-2 in serum samples. We measured blood pressure, waist circumference, serum cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, insulin, glucose, creatinine, hs-CRP, and adiponectin and calculated the BMI and Quicki insulin sensitivity index. In the study on 153 healthy volunteers, we showed that sex and age are not determinative for lipocalin-2 serum values. Furthermore, we tested 45 individuals with metabolic syndrome; values of lipocalin-2 did not differ (78.8 vs. 80.0 microg/l, p =0.56) from the data of healthy individuals from the first study. Neither group differed with regard to sex or age. Lipocalin-2 correlated with alanine aminotransferase (ALT) (r=-0.3, p<0.01) aspartate aminotransferase (AST) (r=-0.3, p<0.01), cholesterol (r=-0.21, p=0.047), creatinine (r=0.19, p=0.05), and high-sensitivity C-reactive protein (hs-CRP) (r=0.22, p=0.036). No significant correlation was found between serum lipocalin-2 and BMI, waist circumference, blood pressure, triglycerides, HDL, Quicki, or the number of metabolic syndrome components. When study patients with metabolic syndrome were further stratified according to the number of components of metabolic syndrome, serum concentrations of lipocalin-2 did not differ. The results presented demonstrate the analytical competence of the lipocalin-2 assay. However, we assumed that lipocalin-2 is not a routinely usable marker of metabolic syndrome or obesity. The association between serum lipocalin-2 and obesity or metabolic syndrome was not validated in our study.     

Proguanylin: development, analytical characterization, and clinical testing of a new ELISA

The aim of our work was to develop an assay for the determination of proguanylin in human blood, and investigate its levels in healthy volunteers and donors suffer from hypertension often accompanied by body sodium accumulation and plasma volume expansion. We developed and evaluated the sandwich ELISA method for the quantitative determination of human proguanylin in serum samples. We conducted also the pilot study on individuals with hypertension and oh healthy probands and measured proguanylin serum levels, serum and urine sodium and creatinine levels. In the study on 256 healthy volunteers we demonstrated that women have significantly higher values of proguanylin than men (medians 12.7 vs. 9.6 ng/ml, p < 0.01) and proguanylin values increased with age of individuals (p < 0.01). Futhermore, we tested 17 individuals with hypertension and found that probands with anamnesi of hypertension had higher proguanylin values than healthy individuals from the first study (medians 16.2 vs. 11.3 ng/ml, p < 0.01). Both of groups did not differ in sex or age. Proguanylin values correlated with the systolic blood pressure (r = 0.41, p < 0.01), sodium fraction excretion (r = 0.72, p < 0.01) and serum sodium (r = -0.39, p < 0.01). No significant correlation we found with serum proguanylin and creatinine. In the group of 9 healthy probands we demonstrated the existence of a diurnal rhythm of proguanylin with its maximum in the evening hours (between 6-10 p.m.). The pilot study supports the hypothesis about the role of proguanylin in sodium metabolism and its possible importance for hypertension disorder. Further research is necessary to confirm our findings in individuals with hypertension with different medication in order to assess proguanylin value as a risk predictor of accelerated hypertension, and to classify individuals with hypertension for variuos types of diuretic therapy.     

Serum adipocyte-specific fatty acid-binding protein is associated with nonalcoholic fatty liver disease in apparently healthy subjects

Adipocyte-specific fatty acid-binding protein (A-FABP) is a cytoplasmic protein that is expressed in adipocytes and is closely associated with insulin resistance, metabolic syndrome, and Type 2 diabetes. We investigated the relationship between A-FABP as a surrogate marker of metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) in apparently healthy subjects. We assessed clinical and biochemical metabolic parameters and measured serum levels of A-FABP, high-sensitivity C-reactive protein and tumor necrosis factor-α (TNF-α) in 494 subjects who were divided into two groups according to the presence of NAFLD by abdominal ultrasonography. All parameters associated with metabolic syndrome were significantly higher in patients with NAFLD (P<.001). A-FABP showed positive correlation with TNF-α, homeostasis model assessment index of insulin resistance (HOMA-IR), and metabolic syndrome (P<.001) when adjusted for age and sex. The odds ratio for the risk of NAFLD in the highest tertile of A-FABP compared with the lowest tertile was 7.36 (CI 3.80-14.27, P<.001) after adjustment for age and sex; 4.52 (CI 2.22-9.20, P<.001) after adjustment for age, sex, HOMA-IR and metabolic syndrome and 2.86 (CI 1.11-7.35, P<.05) after further adjustment for all metabolic parameters including TNF-α. The serum level of A-FABP was independently associated with NAFLD and showed significant correlation with TNF-α, HOMA-IR, and metabolic syndrome.     

Leptin and insulin down-regulate angiopoietin-like protein 3, a plasma triglyceride-increasing factor

We reported previously that angiopoietin-like protein3 (ANGPTL3), a liver-specific secretory factor, increased plasma triglyceride (TG) via inhibition of lipoprotein lipase and free fatty acid (FFA) by activating adipose-lipolysis. The current study examined the regulation of Angptl3 by leptin and insulin, both of which are key players in the metabolic syndrome. Angptl3 expression and plasma ANGPTL3 levels were increased in leptin-resistant C57BL/6J(db/db) and -deficient C57BL/6J(ob/ob) mice, relative to the control. Leptin supplements decreased Angptl3 gene expression and plasma ANGPTL3 in C57BL/6J(ob/ob) mice. The changes of Angptl3 were associated with alterations of plasma TG and FFA levels. Leptin treatment directly suppressed Angptl3 gene expression in hepatocytes. Angptl3 gene expression and plasma protein levels were also increased in insulin-deficient streptozotocin-treated mice. Insulin treatment of hepatocytes decreased Angptl3 gene expression and protein secretion. Our results suggest that elevated ANGPTL3 by leptin- or insulin-resistance is attributed to increased plasma TG and FFA concentrations in obesity.     

Heritability of determinants of the metabolic syndrome among healthy Arabs of the Oman family study

The metabolic syndrome, as defined by the International Diabetes Federation, was investigated in five large, extended, highly consanguineous, healthy Omani Arab families of a total of 1277 individuals. Heritability (h2) of the phenotypic abnormalities that make up the syndrome and other related traits was estimated by variance decomposition method using SOLAR software. The overall prevalence of the syndrome was 23%. The prevalence of abnormalities making the syndrome in a descending order were: obligatory waist circumference, hypertension, raised fasting blood glucose, low serum high-density lipoprotein (HDL), and raised serum triglycerides (TGs). Highly significant, but widely spread, h2 values were obtained for: height (0.68), weight (0.68), BMI (0.68), serum HDL (0.63), serum leptin (0.55), percentage body fat (0.53), total serum cholesterol (0.53), fasting serum insulin (0.51), homeostasis model assessment-insulin resistance index (0.48), serum TG (0.43), waist circumference (0.40), diastolic blood pressure (0.38), and 2-hour glucose level (0.17), whereas for the metabolic syndrome itself, h2 was 0.38. The wide spread of h2 results (0.07 to 0.68) indicates that some determinants, such as weight, BMI, and HDL level, are under significant genetic influence among the Omani Arabs. Other determinants such as insulin resistance, abdominal obesity, diastolic blood pressure, and TG levels seem to be more environmentally driven.     

Effect of haptoglobin subtypes on serum lipid levels

Haptoglobin (Hp) subtypes were analysed by two-dimensional high-resolution gel electrophoresis in 81 Norwegian individuals with moderate hypercholesterolemia and in 316 Norwegian control subjects. The frequencies of the genes Hp2SS and Hp2SF were higher in individuals with hypercholesterolemia than in controls but the differences did not reach statistical significance (p = 0.087). Within the control population, no effect of the different Hp subtypes was found on total serum cholesterol, triglycerides or high-density lipoprotein (HDL) cholesterol. However, in the controls a significantly higher frequency of Hp2-2 types was found among those with HDL cholesterol values in the upper quartile as compared to those with HDL cholesterol in the lower quartile. A similar phenomenon was not uncovered in analyses of total serum cholesterol or triglycerides. Our results are in agreement with others which indicate that genes belonging to the Hp polymorphism play a role in predicting an individual's total serum cholesterol level. However, our data indicate that the cholesterol effect is on the HDL rather than on the total cholesterol level.     

老年不稳定型心绞痛患者血清Irisin、Angptl 2、CTRP1水平与血脂和冠状动脉病变的相关性分析

摘要 目的：探讨老年不稳定型心绞痛（UAP）患者血清鸢尾素（Irisin）、血管生成素样蛋白2（Angptl 2）、C1q肿瘤坏死因子相关蛋白1（CTRP1）水平与血脂和冠状动脉病变的相关性。方法：选择2019年4月至2021年5月期间我院收治的老年UAP患者86例作为观察组,同期在我院体检无冠状动脉病变的志愿者80例作为对照组,比较两组血清Irisin、Angptl 2、CTRP1水平,根据Gensini积分将观察组患者分为轻度病变组28例,中度病变组33例和重度病变组25例,比较各组血清Irisin、Angptl 2、CTRP1及血脂水平,并分析血清Irisin、Angptl 2、CTRP1水平与血脂及Gensini积分的相关性。结果：观察组血清Irisin水平明显低于对照组,Angptl 2、CTRP1水平明显高于对照组（P<0.05）。不同冠状动脉病变程度老年UAP患者血清Irisin、Angptl 2、CTRP1、TC、TG、LDL-C、HDL-C水平比较均有统计学差异（P<0.05）,血清Irisin、HDL-C水平随着冠状动脉病变程度的增加而降低,Angptl 2、CTRP1、TC、TG、LDL-C水平则随着冠状动脉病变程度的增加而升高（P<0.05）。Pearson相关性分析显示：老年UAP患者的血清Irisin水平与TC、TG、LDL-C、Gensini积分呈负相关,而与HDL-C呈正相关（P<0.05）;血清Angptl 2、CTRP1水平与TC、TG、LDL-C、Gensini积分呈正相关,而与HDL-C呈负相关（P<0.05）。结论：老年UAP患者血清Irisin水平降低,Angptl 2、CTRP1水平升高,其水平与患者血脂和冠状动脉病变程度密切相关。     

The influence of laparoscopic adjustable gastric banding and laparoscopic sleeve gastrectomy on weight loss, plasma ghrelin, insulin, glucose and lipids

The aim of this study was to assess the impact of laparoscopic gastric banding and laparoscopic sleeve gastrectomy on the concentration of ghrelin, insulin, glucose, triglycerides, total and HDL-cholesterol, as well as AST and ALT levels in plasma in patients with obesity. The research includes 200 patients operated using LAGB (34 men average age 37.0 ± 12.6 years and 66 women average age 39.18 ± 12.17 years) and LSG (48 men average age 47.93 ± 9.24 years and 52 women, 19 ± 9.33 years). The percentage of effective weight loss, effective BMI loss, concentration of ghrelin, insulin, glucose, triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol, ALT, AST and HOMA IR values was taken preoperatively and at 7th day, 1 month, 3 and 6 months after surgery. Both after LSG and after LAGB, statistically significant reduction in BMI, serum insulin, glucose and HOMA IR was noticed in comparison to the preoperative values. Post LAGB, patients showed an increase of ghrelin, while LSG proved ghrelin decreased. Correlations between glucose and BMI loss, and between insulin and BMI loss in both cases are more favorable in the LSG group. Lipid parameters, AST and ALT have undergone declines or increases in the particular time points. Both techniques cause weight loss and this way lead to changes in the concentration of ghrelin, as well as to the improvement of insulin, glucose, cholesterol and triglycerides metabolism. They reduce metabolic syndrome and multiple comorbidities of obesity.     

Angptl4 deficiency decreases serum triglyceride levels in low-density lipoprotein receptor knockout mice and streptozotocin-induced diabetic mice

Angiopoietin-like protein family 4 (Angptl4) has been shown to regulate lipoprotein metabolism through the inhibition of lipoprotein lipase (LPL). In familial hypercholesterolemia (FH), individuals lacking low-density lipoprotein receptor (LDLR) present not only hypercholesterolemia, but also increased plasma triglyceride (TG)-rich lipoprotein remnants, and develop atherosclerosis. In addition, the most common type of dyslipidemia in individuals with diabetes is increased TG levels.We first generated LDLR^−/−Angptl4^−/− mice to study the effect of Angptl4 deficiency on the lipid metabolism. Fasting total cholesterol, VLDL-C, LDL-C, HDL-C and TG levels were decreased in LDLR^−/−Angptl4^−/− mice compared with LDLR^−/−Angptl4^+/+ mice. In particular, post olive oil-loaded TG excursion were largely attenuated in LDLR^−/−Angptl4^−/− mice compared with LDLR^−/−Angptl4^+/+ mice. We next introduced diabetes by streptozotocin (STZ) treatment in Angptl4^−/− mice and examined the impacts of Angptl4 deficiency. Compared with diabetic Angptl4^+/+ mice, diabetic Angptl4^−/− mice showed the improvement of fasting and postprandial hypertriglyceridemia as well. Thus, targeted silencing of Angptl4 offers a potential therapeutic strategy for the treatment of dyslipidemia in individuals with FH and insulin deficient diabetes.     

Evaluation of Circulating Adipokines and Abdominal Obesity as Predictors of Significant Myocardial Ischemia Using Gated Single-Photon Emission Computed Tomography

Objective

Coronary artery disease (CAD) is associated with abdominal obesity and metabolic syndrome. Adipocytes secrete adipokines, including the newly discovered adipocyte fatty acid binding protein (A-FABP) and chemerin. Adipokines contribute to the pathogenesis of CAD. In patients with CAD, the presence of significant ischemia predicts adverse outcomes. It is unknown whether adipokines can be better predictors of the presence of significant myocardial ischemia than conventional risk factors. This study aimed to compare adipokines with clinical risk factors and abdominal obesity as predictive factors for significant myocardial ischemia.

Methods

One hundred and ninety-six adults with suspected, but unproven, CAD were consecutively enrolled. The main measures were clinical and biochemical parameters and stress myocardial perfusion imaging with gated myocardial perfusion single-photon emission computed tomography (SPECT), with computed tomography (CT) attenuation correction. The abdominal visceral fat area was examined using a hybrid SPECT/CT scanner. Serum levels of high-sensitivity C-reactive protein (hs-CRP) and adipokines (adiponectin, A-FABP, and chemerin) were evaluated.

Results

A-FABP levels correlated significantly with adiponectin, hs-CRP, body mass index, waist circumference, and visceral fat area. A-FABP was significantly associated with metabolic syndrome (OR 3.2, 95% CI 1.6–6.4, p = 0.001), significant myocardial ischemia (OR 1.9, 95% CI 1.0–3.4, p = 0.05), and stress lung-to-heart ratio (β = 0.03, p = 0.03) on SPECT. Chemerin was significantly associated with serum triglyceride levels but not with metabolic syndrome, significant ischemia, or stress lung-to-heart ratio on SPECT. A-FABP was better at detecting significant inducible ischemia than other biomarkers, although this was a modest improvement (area under ROC curve 0.579, 95% CI 0.46–0.69).

Conclusions

Serum A-FABP concentrations correlate significantly with visceral fat area, metabolic syndrome, and predicted significant myocardial ischemia on SPECT. This may help to more accurately assess CAD risk, especially in patients with metabolic syndrome.     

Acipimox reduces circulating levels of insulin and associated neutrophilic inflammation in metabolic syndrome

Metabolic syndrome is a proatherosclerotic condition clustering cardiovascular risk factors, including glucose and lipid profile alterations. The pathophysiological mechanisms favoring atherosclerotic inflammation in the metabolic syndrome remain elusive. Here, we investigated the potential role of the antilipolytic drug acipimox on neutrophil- and monocyte-mediated inflammation in the metabolic syndrome. Acipimox (500 mg) was orally administered to metabolic syndrome patients (n = 11) or healthy controls (n = 8). Serum and plasma was collected before acipimox administration (time 0) as well as 2-5 h afterward to assess metabolic and hematologic parameters. In vitro, the effects of the incubation with metabolic syndrome serum were assessed on human neutrophil and monocyte migration toward the proatherosclerotic chemokine CCL3. Two to five hours after acipimox administration, a significant reduction in circulating levels of insulin and nonesterified fatty acid (NEFA) was shown in metabolic syndrome patients. At time 0 and 2 h after acipimox administration, metabolic syndrome serum increased neutrophil migration to CCL3 compared with healthy controls. No effect was shown in human monocytes. At these time points, serum-induced neutrophil migration positively correlated with serum levels of insulin and NEFA. Metabolic syndrome serum or recombinant insulin did not upregulate CCR5 expression on neutrophil surface membrane, but it increased intracellular JNK1/2 phosphorylation. Insulin immunodepletion blocked serum-induced neutrophil migration and associated JNK1/2 phosphorylation. Although mRNA expression of acipimox receptor (GPR109) was shown in human neutrophils, 5-500 μM acipimox did not affect insulin-induced neutrophil migration. In conclusion, results suggest that acipimox inhibited neutrophil proatherosclerotic functions in the metabolic syndrome through the reduction in circulating levels of insulin.     

Sex-specific and sex-independent quantitative trait loci for facets of the metabolic syndrome in WOKW rats

WOKW rats develop a complete metabolic syndrome closely resembling human disease. Since genetic studies using male (WOKW x DA)F2 progeny showed that several independent genetic factors were involved, a polygenic basis for the syndrome in WOKW was assumed. However, because the metabolic syndrome in human clearly demonstrates sex differences, we have extended our study to include both male and female (WOKW x DA)F2 progeny in a genome-wide scan. Male- or female-specific quantitative trait loci (QTLs) were mapped for body weight, body mass index, adiposity index and serum insulin on chromosomes 1 and 5, serum triglycerides on chromosomes 4, 7, 11, and 16, serum total and high density lipoprotein cholesterol on chromosomes 3, 4, 5, 10, and 17, and serum leptin on chromosomes 8 and 16 as well as blood glucose and glucose tolerance (AUC) on chromosomes 3, 4 and 17. QTLs for both, males and females were only found for body weight on chromosome 1 and for serum total cholesterol on chromosome 3 and 10. These findings clearly demonstrate that there are sex-specific and sex-independent QTLs for facets of the metabolic syndrome in WOKW rats.     

Independent influence of insulin, catecholamines, and thyroid hormones on metabolic syndrome

The objective of this study was to examine whether metabolic syndrome, defined according to adult treatment panel III criteria, is associated with insulin, catecholamines, and thyroid hormones, independently of age and gender. A cohort of 651 euthyroid overweight and obese patients, 440 women and 211 men, aged 18-68 years, were examined. Central fat accumulation (indirectly measured by waist circumference), fasting thyroid-stimulating hormone (TSH), FT(3), FT(4), insulin, glucose, and lipid (cholesterol, HDL-cholesterol, and triglyceride) serum concentrations, 24-h urinary catecholamines, and the level of insulin resistance (estimated by homeostasis model assessment for insulin resistance (HOMA(IR))) were measured. Patients with metabolic syndrome showed higher insulin (P < 0.001) and FT(3) (P < 0.001) serum levels and higher 24-h urinary noradrenaline (P < 0.001) than subjects without this syndrome. The number of metabolic syndrome parameters was directly associated with insulin (P < 0.001) and FT(3) (P < 0.05) serum levels, and with 24-h urinary noradrenaline (P < 0.001) in the whole population. When a multiple regression analysis was performed with the metabolic syndrome as the dependent variable, and age, gender, and insulin, and TSH, FT(3), FT(4) serum levels, and 24-h urinary noradrenaline and adrenaline as independent variables, the metabolic syndrome maintained an independent positive association with age (P < 0.001), male sex (P < 0.001), insulin (P < 0.001), and 24-h urinary noradrenaline (P < 0.001). In conclusion, this study suggests that insulin and noradrenaline cooperate independently to the development of the metabolic syndrome.     

Diet-dependent obesity and hypercholesterolemia in the New Zealand obese mouse: identification of a quantitative trait locus for elevated serum cholesterol on the distal mouse chromosome 5

AIMS: New Zealand obese (NZO) mice exhibit a polygenic syndrome of obesity, insulin resistance, and hypercholesterolemia that resembles the human metabolic syndrome. This study was performed in order to locate genes responsible for elevated serum cholesterol and to compare their effects under a standard and high fat diet.METHODS: A backcross population of NZO with SJL mice (NZO x F1(SJL x NZO)) was generated. Mice were raised on a normal or high fat diet and were monitored for 22 weeks (body weight, serum cholesterol, and blood glucose). A genome-wide scan was performed by genotyping of approximately 200 polymorphic microsatellite markers by PCR and linkage analysis was performed with the MAPMAKER program.RESULTS: In the genome-wide scan, a single susceptibility locus for hypercholesterolemia (Chol1/NZO, maximum LOD score 14.5 in a combined population of 523 backcross mice) was identified on chromosome 5. Cholesterol levels were significantly elevated in both male and female homozygous carriers of the Chol1/NZO allele. The locus maps 40cM distal of the previously described obesity locus Nob1 in the vicinity of the marker D5Mit244 and in the vicinity of hypercholesterolemia QTL previously identified in the NZB, CAST, and C57BL/6J strains. Chol1/NZO was not associated with elevated body weight, serum insulin, or hyperglycemia. The high fat diet significantly increased serum cholesterol levels, but the fat content of the diet did not alter the absolute effect of Chol1/NZO.Conclusions: Chol1/NZO is a major susceptibility locus on the distal mouse chromosome 5, which produces gender-independent hypercholesterolemia in NZO mice. The effect of Chol1/NZO was independent of the dietary fat content and was not associated with the other traits of the metabolic syndrome. Thus, it is suggested that the responsible gene might be involved in cholesterol metabolism.     

Physiology of aging among healthy,older bottlenose dolphins (<Emphasis Type="Italic">Tursiops truncatus</Emphasis>): comparisons with aging humans

Changes in hematological and serum chemistry values have been identified among older compared to younger humans. We hypothesized that healthy bottlenose dolphins (Tursiops truncatus) 30 years and older may demonstrate similar clinicopathological changes with increasing age. Retrospective hematological and serum chemistry data generated from routine, fasted blood samples collected over 10 to 20 years among six healthy dolphins that lived at least 40 years were analyzed to (1) assess linear trends in blood variable values with increasing age, (2) compare mean blood values by older age categories (30–35 years, 36–40 years, and >40 years), and (3) compare the prevalence of clinically high or low blood values by older age categories. Absolute lymphocytes, serum globulins, and mean platelet volume increased linearly with increasing old age. Mean white blood cells, neutrophils, serum globulins, erythrocyte sedimentation rates, serum cholesterol, and serum triglycerides; and the prevalence of neutrophilic leukocytosis, hyperglobulinemia, and hypercholesterolemia, were more likely to be higher as geriatric dolphins got older. A linear decrease in serum albumin with increasing age was present for five of six animals. Serum creatinine decreased among dolphins older than 40 years compared to when they were 30–40 years old. Our study demonstrates that older dolphins have changes in hematological and serum chemistry values similar to those found in older humans. As such, bottlenose dolphins may serve as a useful comparative model for aging in humans. Further studies are needed to assess whether these changes are associated with negative health outcomes and whether targeted therapeutics can help improve quality of life among aging dolphins.     

Association Of Peripheral 5-Hydroxyindole-3-Acetic Acid,A Serotonin Derivative,with Metabolic Syndrome and Low-Grade Inflammation

Objective: The constellation of metabolic abnormalities seen in metabolic syndrome (MetS) has been linked to atherosclerosis and adverse cardiovascular outcomes due to heightened inflammation. Accumulating evidence suggests that peripheral 5-hydroxyindole-3-acetic acid (5-HIAA), the derivative end-product of serotonin (5-HT), might be involved in the pathogenesis of obesity, and abnormal lipid and glucose metabolism. We examined the association between serum 5-HIAA concentrations and MetS and also highly sensitive C-reactive protein (hsCRP).Methods: We assessed 180 healthy adults (110 males and 70 females) in a cross-sectional setting. Anthropometric indices and blood pressure were measured, as were laboratory parameters including fasting 5-HIAA concentrations. The associations between 5-HIAA and individual components of MetS, as well as MetS as a single entity, were investigated with bivariate correlation and logistic regression analyses.Results: Eighty-nine individuals (49.4%) were diagnosed with MetS. Significant correlations were found between 5-HIAA concentrations and age (r = 0.184), waist circumference (r = 0.415), high-density lipoprotein (HDL) cholesterol (r = -0.148), systolic blood pressure (r = 0.374), diastolic blood pressure (r = 0.355), homeostasis model assessment of insulin resistance (r = 0.201), and hsCRP (r = 0.453) were found (P<.05 in all tests). In logistic regression, 5-HIAA was significantly associated with 4 MetS components including central obesity, raised triglycerides, raised blood pressure, and raised fasting plasma glucose (FPG) (P<.05). Moreover, 5-HIAA was a predictor of MetS as a single entity, and the relationship persisted after adjusting for hsCRP (odds ratio [OR] = 4.41, 95% confidence interval [CI]: 2.58-7.67, P<.001).Conclusion: Elevated concentrations of 5-HIAA are seen in individuals with MetS. Increased 5-HIAA is also associated with hsCRP, a marker of chronic lowgrade inflammation underlying MetS.Abbreviations: BMI = body mass index CI = confidence interval FI = fasting insulin FPG = fasting plasma glucose HbA1c = glycated hemoglobin HDL = high-density lipoprotein 5-HIAA = 5-hydroxyindole-3-acetic acid 5-HT = 5-hydroxytryptamine HOMA-IR = homeostatic model assessment of insulin resistance hsCRP = highly sensitive C-reactive protein LDL = low-density lipoprotein MetS = metabolic syndrome OR = odds ratio     

Metabolic Response to Oral Glucose in Healthy South African White,Indian, and African Subjects

The response of serum insulin, growth hormone, plasma free fatty acids, triglycerides, and blood glucose to an oral glucose load was investigated in healthy White, African, and Indian subjects. Serum cholesterol, uric acid, platelet adhesiveness, and urine insulin clearance were also measured. Each racial group responded differently. Most striking were the differences between Africans and Whites; despite similar mean blood glucose values at all times during the test, the Africans had lower serum insulin levels, a lower urine insulin clearance, a much greater rise of growth hormone, a more definite and prolonged suppression of free fatty acid release, lower serum cholesterol and uric acid levels, and a trend towards lower plasma triglyceride values.The Indians tended to resemble Whites rather than Africans with respect to their insulin, growth hormone, cholesterol, and triglyceride levels. Their glucose tolerance was decreased compared with that of the other two groups, but suppression of their free fatty acids was enhanced. Platelet adhesiveness was similar in all three groups.The reasons for these differences are unknown, but must be related to genetic and environmental differences among the three races.     

Leptin and metabolic syndrome in obese and non-obese children.

Metabolic syndrome is characterized by a clustering of metabolic abnormalities: insulin resistance - hyperinsulinemia, dyslipidemia (high triglycerides and low HDL - cholesterol serum concentrations), impaired glucose tolerance and/or type 2 diabetes, and hypertension. The aim of this study was to analyse the role of different variables of metabolic syndrome, including leptin, in 74 non-obese children and 68 children with non-syndromal obesity. As metabolic syndrome variables, we have included body mass index, waist circumference, trunk-to-total skinfolds (%), systolic blood pressure, diastolic blood pressure, glucose, uric acid, fasting insulin, triglycerides and high-density lipoprotein-cholesterol (HDL-C). Factor analysis showed 4 factors in each group. In non-obese children, waist circumference, BMI, fasting insulin, triglycerides, trunk-to-total skinfolds (%), leptin and uric acid loaded positively on factor 1, and HDL-C loaded negatively on this factor; systolic and diastolic blood pressure had high positive loadings in factor 2; HDL-C and leptin showed positive loadings and triglycerides and uric acid, negative loadings in factor 3; and, finally, glucose and insulin showed positive loadings in factor 4. These four factors explained 72.16 % of the total variance in the non-obese group. In obese children, BMI, waist circumference, leptin, diastolic blood pressure and systolic blood pressure loaded positively on factor 1; diastolic blood pressure, trunk-to-total skinfolds (%), uric acid and systolic blood pressure showed high positive loadings in factor 2; fasting insulin, glucose and triglycerides showed positive loadings in factor 3; and, finally, triglycerides showed positive loadings and HDL-C negative loadings in factor 4. These four factors explained 74.18 % of the total variance in the obese group. Our results point to a different homeostatic control of metabolic syndrome characteristics in obese and non-obese children. Leptin seems to play a key underlying role in metabolic syndrome, especially in the obese group.     

Metabolic Hormones,Apolipoproteins, Adipokines,and Cytokines in the Alveolar Lining Fluid of Healthy Adults: Compartmentalization and Physiological Correlates

Objectives

Our current understanding of hormone regulation in lung parenchyma is quite limited. We aimed to quantify a diverse array of biologically relevant protein mediators in alveolar lining fluid (ALF), compared to serum concentrations, and explore factors associated with protein compartmentalization on either side of the air-blood barrier.

Research Design and Methods

Participants were 24 healthy adult non-smoker volunteers without respiratory symptoms or significant medical conditions, with normal lung exams and office spirometry. Cell-free bronchoalveolar lavage fluid and serum were analyzed for 24 proteins (including enteric and metabolic hormones, apolipoproteins, adipokines, and cytokines) using a highly sensitive multiplex ELISA. Measurements were normalized to ALF concentrations. The ALF:serum concentration ratios were examined in relation to measures of protein size, hydrophobicity, charge, and to participant clinical and spirometric values.

Results

ALF measurements from 24 individuals detected 19 proteins, including adiponectin, adipsin, apoA-I, apoA-II, apoB, apoC-II, apoC-III, apoE, C-reactive protein, ghrelin, glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), glucagon, insulin, leptin, monocyte chemoattractant protein-1, plasminogen activator inhibitor-1, resistin, and visfatin. C-peptide and serpin E1 were not detected in ALF for any individual, and IL-6, IL-10, and TNF-alpha were not detected in either ALF or serum for any individual. In general, ALF levels were similar or lower in concentration for most proteins compared to serum. However, ghrelin, resistin, insulin, visfatin and GLP-1 had ALF concentrations significantly higher compared to serum. Importantly, elevated ALF:serum ratios of ghrelin, visfatin and resistin correlated with protein net charge and isoelectric point, but not with molecular weight or hydrophobicity.

Conclusions

Biologically relevant enteric and metabolic hormones, apolipoproteins, adipokines, and cytokines can be detected in the ALF of healthy individuals. For the proteins measured, charge may influence trafficking and compartmentalization to the alveolar airspace more than molecular weight or hydrophobicity. These data may have implications for homeostasis and drug delivery to the lung.