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ABSTRACT: Background Metalloproteinases (MMPs) are synthesized in the subendothelium and are involved in the atherosclerosis and cardiovascular disease process because of their major significance in vascular remodeling and plaque rupture. MMPs are also synthesized in adipose tissue during angiogenesis; however, the role of these enzymes in obesity and insulin-resistant states is still controversial. Objective To evaluate MMP-2 activity in the circulation of overweight and obese women and in normal-weight controls, and to associate the levels of these factors with metabolic, adipose tissue and inflammation biomarkers. Methods Plasma MMP-2 activity, adiponectin and C-reactive protein concentration, lipoprotein profile and HOMA were determined in 39 healthy women (13 normal weight and 26 overweight/obese). Results Overweight/obese women were older (p <0.001) than normal-weight women; 20/26 of overweight/obese women were postmenopausal compared with 4/13 of normal-weight women. Overweight/obese women had significantly higher plasma activity of MMP-2 than controls (mean relative area: 0.81 (range 0.4-1.92) vs. 1.33 (range 0.4-3.1); p <0.005); this difference was lost after adjusting for menopausal status. MMP-2 activity positively correlated with waist circumference (p <0.002), HOMA (p <0.003), and high-sensitivity C-reactive protein (p <0.05), apolipoprotein B (p =0.006) and triglyceride/high density lipoprotein (HDL) cholesterol index (p <0.001), and negatively with HDL cholesterol (p <0.001), HDL2 cholesterol (p <0.008), HDL3 cholesterol (p <0.05) and adiponectin (p <0.05). The association with HOMA and adiponectin persisted even after adjusting for menopausal status. Conclusion Our finding of increased plasma activity of MMP-2 in overweight/obese women, associated with menopausal status, is important given that it fits in with an early stage of cardiovascular disease; the association of MMP-2 activity with obesity markers may be a link between adipose tissue and risk for cardiovascular disease.
Climacteric 05/2012; · 1.99 Impact Factor
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ABSTRACT: Hepatic lipase is a lipolytic enzyme mostly synthesized and localized at the surface of liver sinusoidal capillaries, which hydrolyses triglycerides and phospholipids of intermediate density, large low density (LDL) and high density lipoproteins. Hepatic lipase activity is increased in insulin resistant states. Non-alcoholic fatty liver disease (NAFLD) is characterized by insulin resistance. However, at present, no data are available regarding the behaviour of hepatic lipase with regard to the degree of hepatic steatosis. Our aim was to evaluate hepatic lipase activity in NAFLD patients and its relationship to the severity of hepatic steatosis.
We studied 48 patients with NAFLD (diagnosed by ultrasonography and confirmed by liver biopsy) and 30 controls. Steatosis was semi-quantitatively assessed and considered as mild or grade 1, moderate or grade 2 and severe or grade 3. Measurements: hepatic lipase activity, lipid and lipoprotein profile (including intermediate density lipoproteins and dense LDL), adiponectin, insulin, glucose and high sensitivity C-reactive protein were measured. Homeostasis model assessment for insulin resistance (HOMA) index was calculated.
Patients with hepatic steatosis presented with higher hepatic lipase activity, HOMA and dense LDL and lower levels of adiponectin, high density lipoproteins, cholesterol and apoA-I. Hepatic lipase activity positively correlated significantly with the severity of hepatic steatosis. Hepatic lipase correlated with a more atherogenic profile and persisted higher in patients even after corrected for age, gender, body mass index, HOMA and adiponectin.
The higher hepatic lipase activity in NAFLD patients contributes to a more atherogenic profile linked to increased cardiovascular risk, beyond the insulin resistance and the reduction in adiponectin.
Diabetes/Metabolism Research and Reviews 04/2012; 28(6):535-41. · 3.37 Impact Factor
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ABSTRACT: Several studies have been carried out to characterize the different alterations associated with hypertriglyceridemia (HTG) and to identify this dyslipemia as an independent risk factor for cardiovascular disease (CVD). HTG is frequently, but not always, associated with insulin resistance (IR). The present study was aimed to evaluate if the alterations observed in biomarkers of CVD were similar in HTG states independently of IR.
HTG was defined as triglycerides ≥1.69 mmol/l and IR as HOMA-IR ≥3.1. HTG-IR patients (n=15) were compared with HTG subjects without IR (WIR) (n=15) and with normotriglyceridemic (NTG)-WIR individuals (n=30).
Both HTG groups shared the increment in VLDL-C and non-HDL-C, HDL enrichment in triglycerides and depletion in phospholipids, the decrease in adiponectin concentration, and the increase in CETP activity. HDL-C and VCAM-1 levels were altered only in HTG-IR patients in comparison with the other groups, while oxidized LDL was only higher in HTG-IR than the control group. Multiple regression analysis identified triglycerides as the independent predictor of HDL-C, CETP activity and oxidized LDL levels.
The increase in triglycerides is the major determinant factor of the atherogenic modifications observed, while IR would be an amplifier factor.
Clinica chimica acta; international journal of clinical chemistry 12/2011; 413(5-6):620-4. · 2.54 Impact Factor
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ABSTRACT: The close association between nonalcoholic fatty liver and insulin resistance is now widely recognized. While the former is characterized by excessive intrahepatic triglyceride accumulation, the latter induces overproduction of very-low-density lipoprotein (VLDL) particles. It has not been well elucidated whether these apparently opposite mechanisms impact on VLDL characteristics or not. The aim of the present study was to evaluate the VLDL secretion and features resulting from insulin resistance and fatty liver in rats fed a sucrose-rich diet (SRD, i.e. addition of sucrose to drinking water during 12 weeks). No differences in calorie intake were observed in comparison to controls. Both groups showed similar weight gains throughout the treatment period. However, SRD rats showed an increased proportion of body fat as assessed by X-ray absorptiometry, increased visceral obesity, liver weight and fat accumulation in the liver (p < 0.04). Histological study revealed moderate micro- and macrovesicular steatosis. Fasting insulin, triglyceride and free fatty acid (FFA) levels increased while VLDLs decreased in SRD rats (p < 0.05). The chemical composition of VLDLs of SRD rats showed a higher percentage of triglycerides, and the VLDL triglyceride/protein ratio, an estimator of lipoprotein size, suggests that VLDL particles of SRD rats are larger than those of controls (p < 0.0005). FFA levels correlated with VLDL triglycerides (r = 0.49, p = 0.03) and liver fat content correlated with plasma triglycerides (r = 0.65), VLDL triglycerides (r = 0.55) and triglyceride/protein ratio (r = 0.52, p < 0.02). The VLDL secretion rate assay showed an increase in SRD rats (p < 0.02), confirming an overproduction despite liver fat accumulation. Our findings are consistent with an insulin resistance development model in which hepatic lipid content would constitute an important determinant of a triglyceride-rich, large-particle VLDL secretion; both features would increase its atherogenic potential.
Annals of Nutrition and Metabolism 03/2010; 56(3):198-206. · 2.26 Impact Factor
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ABSTRACT: To establish the relationship between androgens and cardiovascular disease (CVD) risk factors in the menopausal transition.
A total of 124 women were divided into four groups: 29 premenopausal (PreM), 35 women in the menopausal transition still menstruating (MTM), 29 women in the menopausal transition with 3-6 months amenorrhea (MTA), and 31 postmenopausal women (PostM). Levels of triglycerides, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, glucose and insulin were assayed in all samples and waist circumference was measured. In a subgroup of 83 women (19 PreM, 21 MTM, 28 MTA and 15 PostM), levels of total testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS) and estradiol were determined. The free androgen index, Homeostasis Model Assessment (HOMA) index, Quantitative Insulin Sensitivity Check Index (QUICKI) and McAuley index, estradiol/total testosterone and triglyceride/HDL cholesterol ratios were calculated.
Androstenedione was higher in MTA vs. PostM women (p < 0.05); DHEAS was higher in PreM women vs. the other three groups (p < 0.05). Sex hormone binding globulin (SHBG) in MTM women was higher than in MTA women (p < 0.05); the free androgen index was lower in MTM women than in MTA and PostM women. SHBG and the free androgen index showed negative and positive correlations, respectively with waist circumference, insulin resistance and lipids. In a multiple regression analysis, considering waist circumference, neither free androgen index nor SHBG showed significant differences between groups. The waist circumference correlated only with SHBG (p = 0.022) and correlations between SHBG and insulin resistance markers continued to be significant, but relationships between SHBG and lipoproteins and all correlations found with free androgen index were lost.
An increment in the androgenic milieu that correlates with abdominal fat, insulin resistance and atherogenic lipoproteins becomes evident after the menopausal transition and suggests that evaluation of cardiovascular disease risk in these women should include androgens, considering that abdominal obesity is one of the main determinants of the relationship between androgenic parameters and cardiovascular risk factors.
Climacteric 02/2008; 11(6):509-17. · 1.99 Impact Factor
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ABSTRACT: In postmenopausal women (PMW), an adverse lipoprotein pattern and high risk of coronary artery disease has been described. Studies of the mechanisms promoting the higher atherogenic risk observed in healthy PMW are relevant. We evaluated the interactions among several circulating factors involved in the endothelial injury and inflammation in relation to LDL characteristics, beyond LDL cholesterol.
Lipoprotein profile, including apolipoproteins A-I and B, small dense LDL, hepatic lipase, cholesterol transfer protein (CETP), LDL composition and oxidability were assessed in PMW (n=30) in comparison to premenopausal (PreMW, n=28). The following emerging factors were measured: homocysteine, phospholipase A2, ferritin, hs-CRP and fibronectin from extracellular vascular matrix. Insulin-resistance was evaluated by waist circumference, HOMA and TG/HDL cholesterol ratios.
The risk index apo B/apo A-I was significantly increased in PMW (p<0.0001), PMW showed higher proportion of small dense LDL which correlated with the increase in hepatic lipase activity (p<0.005) and with insulin-resistance markers (p<0.05), but not with CETP. Phospholipase A2 (p<0.05), homocysteine (p<0.005), hs-CRP (p<0.005), fibronectin (p<0.05) and ferritin (p<0.0001) were increased in PMW. LDL oxidability positively correlated with waist (p<0.02), homocysteine (p<0.05), fibronectin (p<0.05), hs-CRP (p<0.04), phospholipase A2 (p<0.05), and small dense LDL (p<0.01). After adjusting by menopausal condition, age and waist, LDL oxidability remained associated with waist (beta: 0.35, p=0.047), homocysteine (beta: 0,36 p<0,038), fibronectin (beta: 0,41 p=0.05), and small dense LDL (beta: 0.36, p=0.027).
Evaluation of classic and non-traditional circulating risk factors in hypoestrogenism reflected endothelial and subendothelial inflammation and subclinical atherogenic processes.
Clinica Chimica Acta 06/2007; 381(2):157-63. · 2.54 Impact Factor
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ABSTRACT: To assess the relationship between the main components of both the metabolic syndrome and insulin resistance and menopausal status in the menopausal transition.
A total of 124 healthy women were divided into four groups according to their menstrual status: the first group consisted of 35 women in menopausal transition with menstrual bleeding (MTM) and with cycles between 35 and 80 days; the second group was composed of 29 women in menopausal transition with 3-6 months of amenorrhea (MTA). The third group consisted of 31 postmenopausal women (PostM) and the fourth group of 29 premenopausal women (PreM) with regular cycles. The metabolic syndrome was evaluated following the ATP III criteria. Evaluation of insulin resistance was made through the HOMA, QUICKI and McAuley indices and the triglycerides/high density lipoprotein (HDL) cholesterol ratio.
The triglycerides/HDL cholesterol ratio increased in MTM, MTA and PostM women in comparison with PreM women. A slight decrease in the QUIKI index (p = 0.06) and a decrease in the McAuley index (p < 0.001) were observed in MTM, MTA and PostM women in comparison to PreM women. The relative frequencies of metabolic syndrome in the four groups were: PreM, 0%; MTM, 20%; MTA, 21%; and PostM, 22% (p = 0.0001). The most frequent markers of the metabolic syndrome were increased waist circumference, low HDL cholesterol levels and hypertension. Linear regression between menopausal status and metabolic syndrome was lost when age was added to the model.
The frequency of metabolic syndrome increased from the time of the menopausal transition to the postmenopause. Abdominal obesity was the most frequent feature observed. Nevertheless, aging erased the effect of the menopause on the metabolic syndrome. In order to prevent cardiovascular disease, the metabolic syndrome must be evaluated from the time of the menopausal transition.
Climacteric 02/2006; 9(1):40-8. · 1.99 Impact Factor
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ABSTRACT: To study if the course of cerulein-induced pancreatitis in rats changes in a state of triglyceride-rich lipoprotein metabolism alteration.
Two groups of rats received control diet during a 90-day period (A) and sucrose-rich diet to induce endogenous hypertriglyceridemia (B). Subgroups A2 and B2 received i.p. 45 microg cerulein/kg body weight (to induce acute pancreatitis). Histological examination of pancreas tissue, serum pancreatic lipase, lipoprotein profile and VLDL chemical composition were assessed. Then, pancreatic lipase hydrolytic activity on VLDL-triglycerides was evaluated in vitro.
Cellular vacuolization was observed in all of the cerulein-injected rats, but only in subgroup B2 fat necrosis was present. Serum triglycerides were higher in subgroup B1 than in subgroup A1 (mean +/- SEM, mg/dl 123,77 +/- 25.7 vs. 65.8 +/- 7, p < 0.01). Triglycerides from rats fed with sucrose-rich diet, decreased after cerulein-induced pancreatitis (80.38 +/- 11.3 vs. 123,77 +/- 25.7, p < 0.02). Moreover, the endogenous hypertriglyceridemic rats showed an increment of VLDL triglyceride content, which decreased when rats were injected with cerulein. A negative correlation was found between VLDL-triglyceride content and serum pancreatic lipase activity (r = 0.58, p < 0.02). The in vitro assay showed a decrease in VLDL-triglyceride content post incubation with pancreatic lipase enriched serum (mean +/- SD: 59.2 +/- 27.7%, p < 0.01).
The endogenous hypertriglyceridemia intensifies the course of cerulein-induced pancreatitis and it could be related to the decrease in VLDL-triglycerides as a consequence of pancreatic lipase hydrolytic activity.
Annals of Nutrition and Metabolism 02/2006; 50(1):37-44. · 2.26 Impact Factor
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ABSTRACT: Small dense low-density lipoproteins (LDLs) should be considered a major risk factor for cardiovascular disease, but there is still no recommended method for measuring them or expressing clinical values. We measured the dense LDL portion relatively simply by isolating it using density ultracentrifugation and then giving it a relative, quantitative value.
Dense LDLs (d=1.048-1.063 g/mL) were isolated from human plasma at the same time as total LDL (d=1.021-1.063 g/mL) by means of sequential ultracentrifugation, and the former was assessed as a percentage of the latter. A receiver operator characteristic (ROC) curve was used to compare the different LDL components as markers of dense LDLs. The proposed method was compared with non-denaturing gradient gel electrophoresis (NDGGE). In order to obtain clinical data, the dense LDL portion was measured in diabetic and postmenopausal subjects and healthy controls.
The ROC curve showed that cholesterol level was a more accurate marker of dense LDLs. The within-run precision (CV) was 2.28%, and the between-run CV was 5.1%. Analytical recovery was 80.2+/-1.6%. The correlation between the proposed method and NDGGE was r=0.90, p<0.001. The dense LDL percentage significantly correlated with serum triglyceride (r=0.57, p<0.001) and high-density lipoprotein cholesterol levels (r=-0.33, p<0.01), but not with the LDL-cholesterol/apolipoprotein B ratio. The diabetic patients and postmenopausal women had higher dense LDL values than the healthy controls.
The results obtained using this procedure are in line with those obtained using NDGGE, which is the conventional assay system for measuring LDL size. Determining the small dense LDL portion by means of its cholesterol content may be a better approach to characterising the risk of cardiovascular disease, even in the presence of relatively normal LDL-cholesterol levels.
Nutrition Metabolism and Cardiovascular Diseases 05/2004; 14(2):73-80. · 3.73 Impact Factor
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ABSTRACT: The behavior of lipoproteins during the menopausal transition and their relationship with sex hormones and body fat distribution is still unclear. Our aim was to evaluate atherogenic IDL, LDL, Lp(a) and antiatherogenic HDL lipoproteins in four groups of women: premenopausal (n = 20), menopausal transition women with menstrual bleeding (n = 31), menopausal transition women with 3 to 6 months amenorrhea (n = 36), and postmenopausal women (n = 30). We also measured their FSH, LH and estradiol levels along with BMI and waist circumference. Menopausal transition and postmenopausal women showed higher values of waist circumference (p < 0.0032), LDL-cholesterol (p < 0.002), IDL-cholesterol (p < 0.002) and apoprotein B (p < 0.0001) than premenopausal women. Total-cholesterol (p < 0.0001), triglycerides (p < 0.004), IDL-cholesterol and Lp(a) were higher in menopausal transition women with amenorrhea and in postmenopausal women in comparison with premenopausal women. After adjustment according to age and waist circumference, multiple regression analysis showed the increase in total-cholesterol and LDL-cholesterol to be linearly associated to menopausal status and estradiol concentration, whereas Lp(a) was only related to menopausal status. Age was found to be an independent variable in relation to apoprotein B concentration changes. The effect of menopausal status on TG levels did not remain in the model when age, waist and BMI were included (beta = 0.05, p = 0.356). HDL-cholesterol levels were the same in all the groups. Menopause, age and the increase in abdominal fat distribution were three independent and significant factors impairing lipoprotein profiles from the beginning of the menopausal transition.
Hormone and Metabolic Research 05/2004; 36(4):215-20. · 2.19 Impact Factor
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ABSTRACT: An initial step in the catabolism of triglyceride-rich lipoprotein involves the hydrolysis of the triglyceride moiety by lipoprotein lipase (LPL). As differences in the lipolytic behaviour of very low-density lipoprotein (VLDL) particles have been observed, it is possible that different VLDL particles have a different affinity to the enzyme, which means that their fate may partially depend on the LPL-mediated hydrolysis of their triglyceride content. Our aim was to determine whether variation in VLDL chemical composition affects their properties as a substrate for LPL.
Isolated VLDL was incubated in vitro with bovine LPL to determine substrate affinity. Under optimal assay conditions, free fatty acids were measured and the kinetic indicators for in vitro triglyceride hydrolysis (Km and Vmax) were calculated. VLDL cholesterol (VLDL-C), VLDL-apoB and the cholesterol/triglyceride ratio were assessed and the triglyceride/protein and triglyceride/apoB ratios were calculated as lipoprotein size estimators. VLDL-C, VLDL-apoB and the VLDL-C/triglyceride ratio positively correlated with Km: r = 0.52, p < 0.01; r = 0.52, p < 0.03; r = 0.69, p < 0.001 respectively. No correlation was found between the VLDL-triglyceride/protein or the VLDL-triglyceride/apoB ratios and Km (r = -0.20, and -0.06 respectively, p = not significant). Of the subjects' anthropometric characteristics, only the waist/hip ratio significantly correlated with Km: r = 0.63, p < 0.01.
In the present study, we investigated the substrate function of VLDL particles in vitro. Enzyme affinity seems to be associated with cholesterol-triglyceride content or the number of VLDL particles rather than particle size. It may be expected that VLDL with a low cholesterol/triglyceride ratio will be efficiently lypolised by LPL, thus leading to the formation of a smaller particle with atherogenic potential.
Nutrition Metabolism and Cardiovascular Diseases 03/2002; 12(1):13-8. · 3.73 Impact Factor
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ABSTRACT: Testosterone serum levels may influence the lipoprotein metabolism and possibly atherogenic risk. Our aim was to investigate the effects of long-term testosterone supplementation in hypogonadal men on multiple lipoprotein markers. 18 Hypogonadal men were studied before and after 3, 6, and 18 (n = 7) months of treatment with testosterone enanthate. During treatment, serum testosterone and estradiol increased, reaching normal levels (p < 0.0001 and 0.003, respectively). This was associated with a decrease in HDL cholesterol (from 1.40 +/- 0.10 mmol/l to 1.22 +/- 0.08 mmol/l, p < 0.001) after six months at the expense of HDL2 cholesterol (p < 0.01), as well as apoprotein A1 (from 139 +/- 3.4 mg/dl to 126 +/- 3.0 mg/dl, p < 0.005). Hepatic lipase activity increased (p < 0.05) and correlated positively with testosterone (r = 0.56, p < 0.02) and negatively with HDL cholesterol (r = - 0.58, p < 0.02). Total and LDL cholesterol, triglycerides, and apoprotein B did not increase. Among the seven patients who completed 18 months of treatment, triglycerides, total cholesterol, LDL and HDL cholesterol, as well as total cholesterol/HDL cholesterol ratio values did not differ from baseline while apoprotein A1 (p < 0.03) and HDL cholesterol (p < 0.015) remained decreased and hepatic lipase unchanged. Restoration of testosterone levels in hypogonadal men in this study did not reveal unfavorable changes based on total cholesterol/HDL cholesterol and LDL cholesterol/apoprotein B ratios, which are both atherogenic risk markers. Whether the changes in light of lipoprotein metabolism will adversely influence cardiovascular risk over time remains to be determined.
Hormone and Metabolic Research 02/2002; 34(2):87-92. · 2.19 Impact Factor
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Atherosclerosis 03/1997; 129(1):127-8. · 3.79 Impact Factor
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Medicina 02/1988; 48(5):479-86. · 0.47 Impact Factor
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ABSTRACT: BackgroundIn postmenopausal women (PMW), an adverse lipoprotein pattern and high risk of coronary artery disease has been described. Studies of the mechanisms promoting the higher atherogenic risk observed in healthy PMW are relevant. We evaluated the interactions among several circulating factors involved in the endothelial injury and inflammation in relation to LDL characteristics, beyond LDL cholesterol.MethodsLipoprotein profile, including apolipoproteins A-I and B, small dense LDL, hepatic lipase, cholesterol transfer protein (CETP), LDL composition and oxidability were assessed in PMW (n = 30) in comparison to premenopausal (PreMW, n = 28). The following emerging factors were measured: homocysteine, phospholipase A2, ferritin, hs-CRP and fibronectin from extracellular vascular matrix. Insulin-resistance was evaluated by waist circumference, HOMA and TG/HDL cholesterol ratios.ResultsThe risk index apo B/apo A-I was significantly increased in PMW (p < 0.0001), PMW showed higher proportion of small dense LDL which correlated with the increase in hepatic lipase activity (p < 0.005) and with insulin-resistance markers (p < 0.05), but not with CETP. Phospholipase A2 (p < 0.05), homocysteine (p < 0.005), hs-CRP (p < 0.005), fibronectin (p < 0.05) and ferritin (p < 0.0001) were increased in PMW. LDL oxidability positively correlated with waist (p < 0.02), homocysteine (p < 0.05), fibronectin (p < 0.05), hs-CRP (p < 0.04), phospholipase A2 (p < 0.05), and small dense LDL (p < 0.01). After adjusting by menopausal condition, age and waist, LDL oxidability remained associated with waist (β: 0.35, p = 0.047), homocysteine (β: 0,36 p < 0,038), fibronectin (β: 0,41 p = 0.05), and small dense LDL (β: 0.36, p = 0.027).ConclusionsEvaluation of classic and non-traditional circulating risk factors in hypoestrogenism reflected endothelial and subendothelial inflammation and subclinical atherogenic processes.
Clinica Chimica Acta.
