Effect of drinking on adiponectin in healthy men and women: a randomized intervention study of water, ethanol, red wine, and beer with or without alcohol

OBJECTIVE

Moderate alcohol consumption is associated with reduced incidence of type 2 diabetes and cardiovascular mortality and increases adiponectin concentrations, but effects might differ according to sex and beverage consumed.

RESEARCH DESIGN AND METHODS

A total of 72 healthy individuals (22-56 years) were enrolled in this randomized controlled crossover trial. After washout, two interventions for 3 weeks followed: ethanol (concentration 12.5%), beer (5.6%), or red wine (12.5%) equivalent to 30 g ethanol/day for men and 20 g/day for women or the same de-alcoholized beverages or water. Adiponectin was measured by sandwich enzyme-linked immunosorbent assay.

RESULTS

Among women, adiponectin significantly increased after consuming red wine (29.8%, P < 0.05) and increased among men after ethanol solution (17.4%, P < 0.05) and consuming beer (16.1%, P < 0.05). De-alcoholized beverages had no substantial effect on adiponectin concentrations.

CONCLUSIONS

Moderate amounts of ethanol-containing beverages increased adiponectin concentrations, but sex-specific effects might depend on type of beverage consumed.

Variability of Serial Lipoprotein-Associated Phospholipase A2 Measurements in Post–Myocardial Infarction Patients: Results from the AIRGENE Study Center Augsburg

Background: Of the numerous emerging biomarkers for coronary heart disease (CHD), lipoprotein-associated phospholipase A2 (Lp-PLA2), an enzyme involved in lipid metabolism and inflammatory pathways, seems to be a promising candidate. Implementation of Lp-PLA2 measurement into clinical practice, however, requires data on the reliability of such measurements.

Methods: We measured Lp-PLA2 concentrations by ELISA in blood samples drawn from 200 post–myocardial infarction patients (39–76 years) at 6 monthly intervals between May 2003 and February 2004, for a total of 1143 samples. We estimated analytical, within-individual, and between-individual variation, the critical difference, and the intraclass correlation coefficient of reliability (ICC) to assess the reliability of serial Lp-PLA2 measurements.

Results: The mean (SD) plasma Lp-PLA2 concentration for the study participants was 188.7 (41.8) μg/L, with no significant difference between men and women. The analytical CV for Lp-PLA2 was 4.4%, the within-individual biological CV was 15%, and the between-individual CV was 22%. The ICC was 0.66. An important part of the total variation in plasma Lp-PLA2 concentration was explained by the between-individual variation (as a percentage of the total variance, 66.1%), whereas the within-individual variance was 31.3%. The analytical variance was as low as 2.6%.

Conclusions: Between-individual variation in Lp-PLA2 concentration was substantially greater than within-individual variation. In general, our data demonstrate considerable stability and good reproducibility of serial Lp-PLA2 measurements, results that compared favorably with those for the more commonly measured lipid markers.

Prevalence of non-alcoholic fatty liver and characteristics in overweight adolescents in the general population

Overweight and obesity among children and adolescents are increasing. Fatty liver disease (FLD) is an emerging problem in this age group. We investigated prevalence of overweight and non-invasive FLD and associated clinical characteristics in a representative population-based sample of 378 children and adolescents aged 12-20 years who were randomly selected from the general population in Leutkirch, Southern Germany. Overweight was defined as having a body mass index above the 90th percentile for the respective age and sex. About 15% of female (29 out of 194) and 12% of male participants (22/182) were overweight. Among females, only one non-overweight individual showed signs of FLD but in more than one third of the overweight males (8/22) signs of FLD were present. Overweight subjects in general had an unfavourable lipid profile and abnormal concentrations of obesity-related hormones such as significantly lower concentrations of adiponectin and increased levels of inflammatory markers including C-reactive protein and fibrinogen. Overweight males with signs of FLD showed even more severe altered metabolic responses compared to those who were overweight without signs of liver injury. FLD was not explained by alcohol consumption or other chronic liver disease. In this sample of children and adolescents representative of the general population a high prevalence of non-alcoholic fatty liver disease (NAFLD) is found in overweight males. These individuals showed the most severe metabolic alterations compared to non-overweight and overweight individuals without NAFLD indicating even higher risk for future overweight and obesity-related diseases such as type 2 diabetes and cardiovascular disease.

Different effects of growth factors on proliferation and matrix production of normal and fibrotic human lung fibroblasts

OBJECTIVES AND METHODS

In idiopathic pulmonary fibrosis (IPF), proliferation of fibroblasts and increased matrix deposition result in pulmonary damage and respiratory insufficiency. We cultured human fibroblasts from lung biopsies of healthy adults and of three patients with IPF (histologically usual interstital pneumonitis, UIP) in order to compare proliferation ([(3)H]thymidine incorporation, cell count) and matrix protein expression (immune fluorescence, quantification of fibronectin synthesis using time-resolved immune fluorescence) of normal and UIP fibroblasts in response to various growth factors.

FINDINGS

The growth factors platelet-derived growth factor-BB (PDGF), epidermal growth factor (EGF), insulin growth factor-1 (IGF-1), insulin-like growth factor-2 (IGF-2), tumor necrosis factor alpha (TNFalpha), Transforming growth factor-beta (TGFbeta(1)), and fibroblast growth factor-2 (FGF-2) stimulate proliferation of normal lung fibroblasts significantly more than proliferation of UIP fibroblasts. Immunofluorescence reveals extensive expression of collagen I, collagen III, and fibronectin induced by serum, TGFbeta(1), and TNFalpha. This expression is more pronounced in UIP fibroblasts than in normal fibroblasts. Quantification of fibronectin synthesis reveals an enhanced fibronectin synthesis by UIP fibroblasts in response to PDGF, EGF, IGF-1, IGF-2, TNFalpha, TGFbeta(1), and FGF-2).

CONCLUSIONS

Fibroblasts from normal and UIP lungs differ in their response to growth factors: Whereas normal fibroblasts show a predominantly proliferative response, UIP fibroblasts show an enhanced synthetic activity. Different fibroblast responses may contribute to progressive pulmonary fibrosis in patients with UIP.

Association between Lp-PLA2 and coronary artery disease: focus on its relationship with lipoproteins and markers of inflammation and hemostasis

Lipoprotein-associated phospholipase A2 (Lp-PLA2) generates pro-inflammatory molecules from oxidized LDL. We examined the association between Lp-PLA2 plasma concentrations and risk of stable coronary artery disease (CAD) in a large case-control study and further assessed the relationship between Lp-PLA2 and various lipid, inflammatory and hemostatic parameters. Lp-PLA2 concentrations were measured in 312 patients with CAD and in 479 age- and gender-matched blood donors. Various sensitive inflammatory and hemostatic markers and a complete lipoprotein profile were obtained. Lp-PLA2 concentrations were significantly higher in cases than in controls (296.1 ng/mL versus 266.0 ng/mL, p<0.0001). In multivariable logistic regression, the age- and gender-adjusted OR for the presence of CAD was 1.61 (95% CI, 1.07-2.44) if the top quartile of the Lp-PLA2 distribution was compared to the bottom quartile. Adjustment for traditional cardiovascular risk factors and statin use resulted in an OR of 2.04 (95% CI, 1.19-3.48). After additional controlling for vWF, the OR was slightly attenuated but still remained statistically significant (OR 1.91; 95% CI, 1.12-3.28). Thus, elevated Lp-PLA2 concentrations were associated with the presence of stable CAD, independent of various biochemical markers. Our results support the hypothesis that Lp-PLA2 may be a novel, independent risk marker for CAD.

Lipoprotein-Associated Phospholipase A 2 Adds to Risk Prediction of Incident Coronary Events by C-Reactive Protein in Apparently Healthy Middle-Aged Men From the General Population

Background— Chronic inflammation represents an essential feature of the atherosclerotic process. Lipoprotein-associated phospholipase A 2 (Lp-PLA 2 ), an enzyme mainly produced by monocytes/macrophages, generates potent proinflammatory products.

Methods and Results— Plasma concentrations of Lp-PLA 2 were determined by ELISA in 934 apparently healthy men aged 45 to 64 years sampled from the general population in 1984 and followed up until 1998. During this period, 97 men experienced a coronary event diagnosed according to the MONICA (MONItoring of trends and determinants in CArdiovascular disease) protocol. Baseline levels of Lp-PLA 2 were higher in subjects who experienced an event than in event-free subjects (295±113 versus 263±79 ng/mL, P <0.01). Lp-PLA 2 was positively correlated with total cholesterol ( R =0.30, P <0.0001) and age ( R =0.12, P =0.001), was only slightly correlated with HDL cholesterol ( R =0.09, P =0.005) and C-reactive protein R =0.06, P =0.06), but was not correlated with body mass index or blood pressure. In a Cox model, a 1-SD increase in Lp-PLA 2 was associated with risk of future coronary events (hazard ratio [HR] 1.37, 95% CI 1.16 to 1.62). After controlling for potential confounders, the HR was attenuated but remained statistically significant (HR 1.23, 95% CI 1.02 to 1.47). Further inclusion of C-reactive protein in the model did not appreciably affect its predictive ability (HR 1.21, 95% CI 1.01 to 1.45).

Conclusions— Elevated levels of Lp-PLA 2 appeared to be predictive of future coronary events in apparently healthy middle-aged men with moderately elevated total cholesterol, independent of CRP. This suggests that Lp-PLA 2 and CRP may be additive in their ability to predict risk of coronary heart disease.

Essential role of calcium in vascular endothelial growth factor A-induced signaling: mechanism of the antiangiogenic effect of carboxyamidotriazole

Vascular endothelial growth factor-A (VEGF-A) plays a major role in tumor angiogenesis and raises the concentration of intracellular free calcium ([Ca2+]i). Carboxyamidotriazole (CAI), an inhibitor of calcium influx and of angiogenesis, is under investigation as a tumoristatic agent. We studied the effect of CAI and the role of [Ca2+]i in VEGF-A signaling in human endothelial cells. VEGF-A induced a biphasic [Ca2+]i signal. VEGF-A increased the level of intracellular inositol 1,4,5-trisphosphate (IP3), which suggests that VEGF-A releases Ca2+ from IP3-sensitive stores and induces store-operated calcium influx. Reduction of either extracellular or intracellular free Ca2+ inhibited VEGF-A-induced proliferation. CAI inhibited IP3 formation, both phases of the calcium signal, nitric oxide (NO) release, and proliferation induced by VEGF-A. CAI prevented neither activation of VEGF receptor-2 (VEGFR-2) (KDR/Flk-1), phospholipase C-g, or mitogen-activated protein kinase (MAP kinase) nor translocation of nuclear factor of activated T cells (NFAT). We conclude that calcium signaling is necessary for VEGF-A-induced proliferation. MAP kinase activation occurs independently of [Ca2+]i but is not sufficient to induce proliferation in the absence of calcium signaling. Inhibition of the VEGF-A-induced [Ca2+]i signal and proliferation by CAI can be explained by inhibition of IP3 formation and may contribute to the antiangiogenic action of CAI. Calcium-dependent NO formation may represent a link between calcium signaling and proliferation.

Vascular endothelial growth factor-A activates Ca2+ -activated K+ channels in human endothelial cells in culture

Vascular endothelial growth factor-A (VEGF-A) is an endothelial-cell specific growth factor and leads to an increase in cytosolic free calcium ([Ca2+](i)) in endothelial cells. Ca2+ -activated K+ channels (KCa-channels) have been suggested to facilitate calcium influx by hyperpolarising the cell and thus increasing the electrochemical driving force for calcium influx. The patch-clamp technique was used to investigate the effect of VEGF-A on large conductance KCa-channels. The role of these channels in VEGF-induced proliferation (cell count, [3H]thymidine incorporation) was studied using the specific inhibitor iberiotoxin. VEGF-A strongly stimulated KCa-channel activity and led to a 14.2 +/- 4.8 fold (SEM, n = 12) increase in activity after 8 min of VEGF-A stimulation. The VEGF-A-induced activation occurred in calcium-free solution as well (16.7+/-2.2 fold, SEM, n = 5) whereas carboxyamidotriazole (CAI), an antiangiogenic drug which inhibits both Ca2+ influx and Ca2+ release from intracellular stores, completely blocked VEGF-A-induced KCa channel activation. Specific inhibition of KCa channel activity with iberiotoxin did not inhibit proliferation of endothelial cells induced by VEGF-A and or basic fibroblast growth factor (bFGF). In conclusion, we show that VEGF-A activates KCa-channels in HUVEC. However, KCa channel activity is not involved in VEGF-A- or bFGF-induced endothelial-cell proliferation. Since hyperpolarization of endothelial cells secondary to KCa-channel activation is electrically transmitted to vascular smooth muscle cells, which relax in response to hyperpolarization, the VEGF-A-induced KCa channel activation might contribute to VEGF-A-induced vasorelaxation.

Non-human primate pancreas as a substrate for the detection of islet-cell antibodies in human sera

In an effort to find out if the use of non-human primate pancreas may improve the sensitivity of the islet cell antibody (ICA) test, the sera from patients with type 1 diabetes (insulin-dependent IDDM) and controls were investigated by indirect immunofluorescence (IFL) on both human and baboon substrates. The mean titers of positives were insignificantly higher (1:24.9) on baboon as compared to human tissue (1:22.3). Of 50 sera from IDDM patients positive for ICA on human tissue, 47 were also positive on baboon pancreas. Of 40 ICA-negative IDDM sera two were judged positive on baboon substrate. ICA were positive on human/baboon pancreas in 3/4 out of 50 first-degree relatives of IDDM patients, 2/2 of 50 sera from patients with autoimmune diseases, 0/0 of 50 sera from type 2 diabetics and 2/1 of 100 mixed hospital controls. A disadvantage of baboon pancreas for ICA testing by IFL is the high background fluorescence given by the exocrine pancreas. With baboon tissue, three highly positive results would have been missed with undiluted sera which are usually used in this assay. It is therefore suggested that human pancreas should still be preferentially used for ICA determination, but baboon tissue may be a valuable substitute.

[Dissociation of serum kinetics of amylase and trypsin following stimulation with secretin and pancreozymin]

The diagnostic value of basal serum trypsin and amylase values in the assessment of pancreatic exocrine function is limited. Secretin injection evokes a significantly different response in the serum kinetics of trypsin and amylase, due probably to their difference in molecular weight (21,000 vs 52,000 Daltons). Serum trypsin increases in 70% of people with normal secretin-pancreozymin test after stimulation with secretin, whereas amylase remains unchanged. The post-stimulatory rise in trypsin is lower in mild exocrine insufficiency and almost completely abolished in severe exocrine insufficiency. The diagnosis of severe exocrine insufficiency is confirmed in 93% and that of mild insufficiency in 54% by low basal and post-stimulatory levels of serum trypsin. In diabetics with low basal values the post-stimulatory rise in serum trypsin confirmed normal pancreatic function. The poststimulatory kinetics of serum amylase shows no clear correlation to pancreatic function. From the divergent serum kinetics of trypsin and amylase it may be concluded that trypsin is primarily of ductular and amylase primarily of acinar origin.

[Diagnostic significance of pancreatic serum-enzyme patterns after stimulation with secretin in chronic pancreatitis (author's transl)]

The pancreatic serum evocation test with secretin has regained importance now that it is possible to determine immunoreactive trypsin and pancreatic isoamylase. After secretin stimulation there was a significant abnormal increase in serum trypsin (p less than 0.01) in 34 patients with proven chronic pancreatitis associated with mild to moderate dysfunction (groups I-II), no rise if there was marked insufficiency (group III). Patients with steatorrhoea and obstruction in the region of the head of the pancreas formed a special group because, contrary to other patients in groups III, they had marked serum enzyme rise after secretin. In 24 control subjects with a normal pancreas there was no significant change in basal pancreatic serum enzyme levels with secretin stimulation. Trypsin and amylase reaction patterns differed during secretin stimulation, with a rise in the amylase occurring at the expense of pancreas isoamylase.