The association between neutrophil gelatinase-associated lipocalin and clinical outcome in chronic heart failure: results from CORONA*.

OBJECTIVE: To study the prognostic value of neutrophil gelatinase-associated lipocalin (NGAL) in chronic heart failure (HF) of ischaemic aetiology. BACKGROUND: Neutrophil gelatinase-associated lipocalin is a marker of kidney injury as well as matrix degradation and inflammation and has previously been shown to be increased in HF. We investigated whether serum NGAL levels could provide prognostic information in chronic HF. METHODS: We assessed NGAL as a predictor of primary outcomes (cardiovascular death, nonfatal stroke and nonfatal myocardial infarction, n = 307) and all-cause mortality (n = 321), cardiovascular mortality (n = 259) and hospitalization (n = 647) as well as the number of hospitalizations during follow-up for all (n = 1934) and CV causes (n = 1204) in 1415 patients with chronic HF (≥60 years, New York Heart Association class II-IV, ischaemic systolic HF) in the CORONA population, randomly assigned to 10 mg rosuvastatin or placebo. Results. Multivariate analysis revealed that NGAL added significant information when adjusting for clinical variables, but was no longer significant when further adjusting for apolipoprotein A-1 (ApoA-1), glomerular filtration rate (GFR), C-reactive protein (CRP) and N-terminal pro-brain natriuretic peptide (NT-proBNP). However, belonging to the highest NGAL tertile was associated with more frequent hospitalization, even after adjusting for clinical variables, GFR and ApoA-1, but not after adjusting for CRP and NT-proBNP. There was no interaction between rosuvastatin treatment and NGAL. Conclusion. Neutrophil gelatinase-associated lipocalin added no significant information to NT-proBNP and GFR in a multivariate model for primary and secondary end-points.

Association between impaired glucose tolerance and carotid atherosclerosis: a study in 64-year-old women and a meta-analysis.

BACKGROUND AND AIMS: Impaired glucose tolerance (IGT) is regarded as a transient metabolic state leading to type-2 diabetes, and is known to predict future risk of cardiovascular disease. This study was designed to investigate if IGT is associated with subclinical atherosclerosis. METHODS AND RESULTS: In a population-based cohort of 64-year-old women, a group with IGT determined by repeated oral glucose tolerance tests (n=205) was compared with healthy women with normal glucose tolerance (NGT, n=188). Intima-media thickness (IMT) and plaques in the common carotid arteries (CCA) and bulbs were measured by ultrasound. The 95% confidence interval (CI) of the difference between the IGT and NGT groups was -0.03 to 0.03mm. There was no difference in carotid bulb IMT or in the occurrence, size, and characteristics of plaques between the IGT and NGT groups. A meta-analysis was used to calculate summary measures of 12 reviewed studies showing a difference of 0.030 (95% CI 0.012-0.048) mm in carotid IMT between IGT and NGT groups. Heterogeneity in IMT differences between studies was shown. CONCLUSIONS: In our population-based cohort of 64-year-old women, IGT was not associated with increased occurrence of subclinical atherosclerosis. However, a meta-analysis of 12 studies, including our current study, showed that IGT was associated with a small increase in the CCA IMT.

Circulating matrix metalloproteinase 9 levels in relation to sampling methods, femoral and carotid atherosclerosis.

OBJECTIVES: To examine whether circulating levels of matrix metalloproteinase 9 (MMP-9) were associated with ultrasound-assessed intima-media thickness (IMT) and echolucent plaques in the carotid and femoral arteries. To examine preanalytical sources of variability in MMP-9 concentrations related to sampling procedures. SUBJECTS AND DESIGN: Plasma and serum MMP-9 levels were compared with ultrasound assessed measures of femoral and carotid atherosclerosis, in a cross-sectional study of 61-year-old men (n = 473). Preanalytical sources of variability in MMP-9 levels were examined in 10 healthy subjects. Main outcome measures were circulating levels of MMP-9 in serum and plasma, IMT of the carotid and femoral arteries, and plaque status based on size and echolucency. SETTING: Research unit at university hospital. RESULTS: Plasma concentrations of total and active MMP-9 were associated with femoral artery IMT independently of traditional cardiovascular risk factors, and were higher in subjects with moderate to large femoral plaques. Plasma MMP-9 concentration was higher in men with echolucent femoral plaques (P = 0.006) compared with subjects without femoral plaques. No similar associations were found for carotid plaques. MMP-9 concentrations were higher in serum than in plasma, and higher when sampling was performed with Vacutainer than with syringe. MMP-9 levels in serum were more strongly associated with peripheral neutrophil count compared with MMP-9 levels in plasma. CONCLUSIONS: Plasma MMP-9 levels were associated with atherosclerosis in the femoral artery, and total MMP-9 concentration was higher in men with echolucent femoral plaques. The choice of sample material and sampling method affect the measurements of circulating MMP-9 levels.

Inflammatory markers in relation to insulin resistance and the metabolic syndrome.

BACKGROUND: Inflammation has repeatedly been demonstrated to be associated with the metabolic syndrome (MetS) and insulin resistance, but the relative importance of different aspects of the inflammatory process is largely unexplored. DESIGN: We measured circulating interleukins (IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10); other cytokines (tumour necrosis factor-alpha, interferon gamma and monocyte chemotactic protein-1), cell adhesion molecules [vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1, E-selectin, P-selectin, l-selectin], and systemic inflammation markers [C-reactive protein (CRP) and leukocyte count] in 943 70 year old participants (50% women) of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. We related these biomarkers to MetS and the homeostasis model assessment insulin resistance index (HOMA-IR). RESULTS: In a multivariable model including all inflammatory markers conjointly together with sex, log VCAM-1 [odds ratio (OR), 1.45; 95% confidence interval (CI), 1.22-1.72 per 1 SD increase; P < 0.0001], log E-selectin (OR, 1.33; 95% CI, 1.12-1.57 per 1SD increase; P = 0.001), and log CRP (OR, 1.41; 95% CI, 1.20-1.66 per 1-SD increase; P < 0.0001) were independently associated with MetS. These biomarkers were also independently associated with HOMA-IR. CONCLUSIONS: Among 17 inflammatory biomarkers, most of them previously not examined in relation to MetS and insulin resistance, VCAM-1, E-selectin and CRP demonstrated the strongest associations with MetS and insulin resistance in our community based sample of the elderly. The relative importance of these biomarkers in predicting the development of MetS, insulin resistance and cardiovascular disease needs to be further examined in a longitudinal setting.

Release of protein as well as activity of MMP-9 from unstable atherosclerotic plaques during percutaneous coronary intervention.

OBJECTIVES: Few studies have investigated the composition of unstable coronary plaques in vivo in humans. The aims of this study were to investigate if substances released from plaques during percutaneous coronary intervention (PCI) under distal protection could give information about plaque composition and also indicate possible biomarkers in plasma that may be used to identify patients at risk. METHODS AND RESULTS: Twenty patients with acute coronary syndromes undergoing PCI with distal protection were included. Plasma samples were taken before, during, and after the PCI in the aortic root, locally in the culprit vessel and intravenously. Plasma was analysed for possible markers of plaque instability. During PCI, local increases were observed for matrix metalloproteinase 9 (MMP-9), protein (P < 0.001) as well as activity (P < 0.001), interleukin 6 (IL-6; P < 0.01) and oxidized low-density lipoprotein (oxLDL; P = 0.01) in the culprit coronary artery. A systemic inflammatory response was also seen with increased levels of IL-10, MMP-3, serum amyloid A and C-reactive protein, but with no increase in MMP-9. CONCLUSIONS: Our study shows that local sampling of blood under distal protection may be used to analyse coronary plaques and to identify biomarkers for unstable plaques. Our results suggest that MMP-9 is a potential biomarker, and that IL-6, MMP9 and possibly oxLDL are released from plaques.

apoB/apoA-I ratio is related to femoral artery plaques and is predictive for future cardiovascular events in healthy men.

OBJECTIVES: The aim of the present study was to investigate the association between serum concentrations of apoB, apoA-I and the apoB/apoA-I ratio and future cardiovascular events in a group of healthy 58-year-old men during 6.6 years of follow-up. A further aim was to investigate the concentrations of apoB, apoA-I and the apoB/apoA-I ratio to the association of plaque occurrence in the carotid and femoral arteries. BACKGROUND: Previous studies have shown that the apoB/apoA-I ratio is an important cardiovascular risk factor, whereas the association between apoB/apoA-I ratio and presence of atherosclerotic plaques in the carotid and femoral arteries has been less investigated. METHODS: The carotid and femoral arteries were examined by high-resolution B-mode ultrasound in 391, 58-year-old men identified by screening in the city of Göteborg, Sweden. Assessment of plaque occurrence and measurement of apolipoproteins (apoA-I and apoB) was performed. RESULTS: Subjects with an apoB/apoA-I ratio >/=0.9 had a significantly increased risk to suffer a cardiovascular event during 6.6 years of follow-up (OR 3.07, 95% CI 1.22-7.71), while no difference in risk for cardiovascular events was observed for subjects with LDL cholesterol >3.4 mmol/L compared to subjects <3.4 mmol/L (OR 1.04, 95% CI 0.37-2.46). A greater risk for plaques in the femoral artery was also observed in subjects with an apoB/apoA-I ratio >/=0.9 compared to subjects <0.9 (OR 3.06, 95% CI 1.22-7.70). In a multiple logistic regression model, both elevated apoB/apoA-I ratio and plaque occurrence in the femoral artery were of significant importance for cardiovascular events during follow-up. CONCLUSIONS: The results showed that the apoB/apoA-I ratio was associated with arteriosclerosis in the femoral artery, and predicted future cardiovascular events. These observations, and the fact that apoB and apoA-I can be measured in the non-fasting state with high precision, in combination with the finding that LDL cholesterol did not predict cardiovascular disease, support results from other studies that the apoB/apoA-I ratio may be a superior risk marker for cardiovascular disease.

Antibodies to oxidized LDL in relation to intima-media thickness in carotid and femoral arteries in 58-year-old subjectively clinically healthy men.

Antibody (Ab) titers to oxidized low density lipoprotein (OxLDL) have been found to be independent predictors of the progression of carotid atherosclerosis. Ab titers against OxLDL may be related to the entire burden of atherosclerosis in the vascular tree or, more specifically, to the disease process in different arterial regions. Therefore, the aim of the present study was to investigate the relationship between IgG and IgM titers to modified LDL and intima-media thickness (IMT) in the carotid and femoral arteries in subjectively clinically healthy 58-year-old men. IMT was measured by ultrasound, and Ab titers to modified LDL were measured by ELISA. The results showed that the common carotid artery IMT was associated with elevated titers of IgG-OxLDL Ab and independently with systolic blood pressure, smoking, and body mass index. The femoral artery IMT showed a negative correlation to IgM-OxLDL Ab and independent associations with smoking, systolic blood pressure, and total cholesterol. To summarize, in 58-year-old subjectively clinically healthy men recruited from the general population, there was a positive association between IgG-OxLDL Ab and IMT in the common carotid artery and a negative association between IgM-OxLDL Ab and IMT in the common femoral artery. However, these associations were not independent of other risk factors.

The metabolic syndrome, LDL particle size, and atherosclerosis: the Atherosclerosis and Insulin Resistance (AIR) study.

An operative definition of the metabolic syndrome has been suggested by a working group associated with the World Health Organization in 1998. The aim of this study was to examine whether small, low density lipoprotein (LDL) particle size was associated with the metabolic syndrome and with subclinical atherosclerosis as measured by ultrasound in the carotid and femoral arteries. The study was performed in a population-based sample of clinically healthy men (N=391), all 58 years old and not undergoing any treatment with cardiovascular drugs. Exclusion criteria were cardiovascular or other clinically overt diseases or continuous medication with cardiovascular drugs. The results showed that subjects characterized by the metabolic syndrome (n=62) had a thicker mean intima-media complex (IMT) in both the carotid and femoral arteries (0.86 versus 0.77 mm, P:<0.001, and 1.03 versus 1. 00 mm, P:=0.022, respectively) and also lower mean values for LDL particle size (25.78 versus 26.80 nm, respectively, P:<0.001) compared with subjects with no risk factors (n=77). The group with the metabolic syndrome (n=62) also had higher mean values for serum cholesterol and heart rate. In the whole study group (N=391), there were significant but weak negative relationships between small LDL particle size, increasing IMT, and increasing cross-sectional intima-media area of the carotid and femoral arteries and also negative relationships between LDL particle size and plaque occurrence and size in the carotid and femoral arteries. In summary, this is the first large-scale study to demonstrate a relationship between the clustering of risk factors that constitute the metabolic syndrome and a small LDL particle size pattern and the occurrence of preclinical atherosclerosis in the carotid and femoral arteries, as assessed by the ultrasound technique, in healthy 58-year-old men recruited from the general population.

Antibodies to oxidized LDL in relation to carotid atherosclerosis, cell adhesion molecules, and phospholipase A(2).

-The role of the humoral immune response to oxidized low density lipoprotein (Ox-LDL) in atherogenesis is unclear and available studies are contradictory. The aims of the present study were (1) to compare antibody titers to modified LDL in a group of patients with hypercholesterolemia (n=102) with those in matched controls (n=102), (2) to analyze whether these titers were related to atherosclerosis development as measured by ultrasound, and (3) to analyze whether these titers were related to soluble cell adhesion molecules and secretory type II phospholipase A(2) in plasma. The results showed that male patients with hypercholesterolemia had lower immunoglobulin G (IgG) titers compared with those in healthy controls. In the control group, there was an inverse correlation between intima-media thickness of the carotid artery bulb and IgM titers against Ox-LDL and malondialdehyde-LDL (r=-0.35, P:=0.001; and r=-0.31, P:=0.003, respectively). In the patient group, however, only weak associations were seen. IgG titers were positively associated with soluble intercellular adhesion molecule-1, soluble E-selectin, and secretory type II phospholipase A(2). Taken together, the results of this study support the concept that the humoral immune response against Ox-LDL may be protective in early atherosclerosis. The pattern, however, is complex, and the role of the immune response may differ in different patient groups as well as at different stages of the disease.

Soluble intercellular adhesion molecule-1 is related to endothelial vasodilatory function in healthy individuals.

OBJECTIVE: To investigate the associations between markers of systemic and vascular inflammation, and indicators of vascular morphology and function. METHODS: In 59 apparently healthy individuals, we measured serum levels of highly sensitive C-reactive protein (hsCRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Endothelium-dependent (EDV) and -independent (EIDV) vasodilatation was evaluated in the forearm by venous occlusion plethysmography and local infusions of methacholine and sodium nitroprussid. Endothelial function index (EFI) was expressed as the EDV/EIDV ratio. The intima-media thickness (IMT) of the common carotid artery was investigated with ultrasound (far wall). RESULTS: EFI was inversely related only to ICAM-1 (r=-0.31, P<0.02) by univariate analysis. This association remained significant after adjustment for age, sex, blood pressure, smoking and serum cholesterol. EFI did not relate to hsCRP, VCAM-1 or E-selectin. Neither hsCRP, nor the adhesion molecules were significantly related to carotid artery IMT. CONCLUSION: ICAM-1 was related to endothelial vasodilatory function, but not to IMT, suggesting that endothelial inflammatory activation is related to an impaired vascular relaxation in apparently healthy individuals.

Low-density lipoprotein particle size, insulin resistance, and proinsulin in a population sample of 58-year-old men.

The relationship between insulin sensitivity and low-density lipoprotein (LDL) peak particle size was examined in 104 clinically healthy 58-year-old men recruited from the general population. Insulin sensitivity was measured by the euglycemic hyperinsulinemic clamp method with adjustment for lean body mass. LDL peak particle size was determined by gradient gel electrophoresis, and insulin, proinsulin, and 32,33 split proinsulin were determined by 2-site immunoradiometric assays. The results showed that 16 subjects (15%) had pattern B, with a predominance of small LDL particles. These cases and a small LDL peak particle size were characterized by the features of the insulin resistance syndrome, ie, general and central obesity, elevated diastolic blood pressure, low serum concentrations of high-density lipoprotein (HDL) and apolipoprotein A1 (apoA1), increases in serum triglycerides and circulating insulin peptides, and low insulin-mediated glucose uptake. The correlation between insulin sensitivity and LDL peak particle size was significant (r = .33, P = .001) and independent of obesity. In a traditional multiple regression analysis, LDL peak particle size was independently associated not with insulin-mediated glucose uptake but with circulating triglycerides and HDL cholesterol, which together explained 67% of the variability in LDL particle size (P = .000). Of all insulin peptides, only proinsulin showed an independent relation to LDL peak particle size, but it disappeared after adjustment for other variables. We conclude that a small LDL particle size was associated with insulin resistance among these clinically healthy men, but this was not independent of serum triglycerides and HDL cholesterol. Serum proinsulin was more directly related to LDL particle size than insulin.

Visceral adipose tissue, adiponectin levels and insulin resistance are related to atherosclerosis as assessed by whole-body magnetic resonance angiography in an elderly population.

OBJECTIVE: The principal aim of this study was to determine whether the amount of visceral adipose tissue (VAT) is more related than subcutaneous adipose tissue (SAT) to atherosclerosis assessed by whole-body MRA (WBMRA). A further objective was to investigate whether traditional risk factors, inflammation, or adipokines could explain the hypothesized relationship between VAT and atherosclerosis. METHODS: Men and women aged 70 were recruited from the general population into the Prospective Investigation of The Vasculature in Uppsala Seniors (PIVUS) and 306 of them underwent WBMRA in a clinical 1.5-T scanner. The arterial tree was assessed for degree of stenosis or occlusion and a total atherosclerotic score (TAS) was established. Information on risk factors and BMI and on SAT and VAT, segmented on an axial MR scan was collected. Adiponectin, leptin, and high sensitive C-reactive protein (hsCRP) were measured in serum. HOMA index was used as a marker of insulin resistance. RESULTS: VAT was related to TAS independently of gender, total obesity (BMI), amount of SAT, hsCRP and also to the traditional risk factors included in the Framingham risk score (FRS) in an elderly population. Adiponectin or the HOMA insulin resistance, but not leptin or VAT, together with FRS was significantly related to TAS in a multiple censored regression model. CONCLUSION: Adiponectin attenuated the relationship between VAT and TAS, suggesting that adiponectin and insulin resistance is an important link between visceral adiposity and atherosclerosis.

Circulating oxidized LDL is associated with the occurrence of echolucent plaques in the carotid artery in 61-year-old men.

OBJECTIVE: The aim of this study was to elucidate the relationship between the echogenicity of carotid artery plaques and the following risk factors: circulating oxLDL, hsCRP, the metabolic syndrome (MetS), and several of the traditional cardiovascular (CV) risk factors. MATERIAL AND METHODS: A cross-sectional population-based study of 513 sixty-one-year-old men. The levels of circulating oxLDL were determined in plasma samples by sandwich ELISA utilizing a specific murine monoclonal antibody (mAb-4E6). High-sensitivity CRP was measured in plasma by ELISA. Plaque occurrence, size and echogenicity were evaluated from B-mode ultrasound registrations in the carotid arteries. Plaque echogenicity was assessed based on a four-graded classification scale. RESULTS: A higher frequency of echolucent carotid plaques was observed with increasing levels of oxLDL and systolic blood pressure (p = 0.008 and p = 0.041, respectively). Subjects with the MetS had a significantly higher frequency of echogenic plaques than subjects without the MetS (p = 0.009). In a multiple logistic regression analysis, oxLDL turned out to be independently associated with echolucent carotid plaques. CONCLUSIONS: The occurrence of echolucent carotid plaques was associated with oxLDL and systolic blood pressure, and oxLDL was associated with echolucent carotid plaques independently of systolic blood pressure.

Are serum adiponectin concentrations in a population sample of 64-year-old Caucasian women with varying glucose tolerance associated with ultrasound-assessed atherosclerosis?

OBJECTIVE: To examine whether serum adiponectin concentrations were associated with subclinical atherosclerosis assessed as intima media thickness (IMT) in the carotid arteries in Caucasian women with varying degrees of glucose tolerance. RESEARCH DESIGN AND METHODS: From a population-based cohort of 64-year-old Swedish women, 533 subjects with type 2 diabetes (DM2, n=177), impaired glucose tolerance (IGT; n=178) or normal glucose tolerance (NGT, n=178) were recruited. Anthropometrics, usual cardiovascular risk factors were examined and ultrasound examination of the carotid arteries was performed. RESULTS: Women with low adiponectin concentrations were characterized by thick IMT, higher prevalence of DM2, history of previous myocardial infarction, angina pectoris, anti-hypertensive treatment and high body mass index (BMI), waist circumference, plasma insulin, serum triglycerides, fasting glucose, HbA1c, and low serum HDL cholesterol levels. Carotid IMT correlated with HbA1c (r=0.24, P<0.001), waist circumference (r=0.22, P<0.001), plasma insulin (r=0.19, P<0.001), BMI (r=0.18, P<0.001), DM2 (r=0.16, P<0.001), systolic blood pressure (r=0.16, P<0.001), blood glucose (r=0.16, P<0.001), triglycerides (r=0.15, P<0.001), and reversely to adiponectin (r=-0.11, P=0.01), HDL cholesterol (r=-0.13, P=0.004), and alcohol intake (r=-0.087, P<0.05). A more detailed analysis of underlying associations was difficult due to a high co-linearity between these variable. CONCLUSIONS: Low serum adiponectin concentrations were associated with increased carotid artery IMT, and several risk factors for cardiovascular diseases, mainly those constituting the metabolic syndrome.

The metabolic syndrome in middle-aged men according to different definitions and related changes in carotid artery intima-media thickness (IMT) during 3 years of follow-up.

OBJECTIVES: To examine the occurrence over time of the metabolic syndrome (MetS) according to different definitions and the relation to change during follow-up in carotid artery intima-media thickness (IMT), measured by ultrasound. DESIGN: A cohort of 316, originally 58-year-old men, initially free of diabetes and cardiovascular disease, was followed for 3.2 +/- 0.2 years. IMT was measured bilaterally by high-resolution B-mode ultrasound at baseline and follow-up. The MetS was classified according to slightly modified World Health Organization (WHO) and National Cholesterol Education Program (NCEP) criteria. RESULTS: In 88% WHO and NCEP definitions resulted in identical classifications. IMT was larger both at baseline and after 3 years in men fulfilling the criteria for the MetS, according to either of the definitions, compared to those without factors in the syndrome. Men who fulfilled the WHO criteria for the MetS, at the initial and final examination showed a statistically significant increase in carotid artery IMT during the study [76 (95% CI: 14-130) microm, n = 37]. Men fulfilling the WHO criteria for the MetS at baseline tended to have a larger annual increase in IMT than those not fulfilling the criteria or having no risk factors in the syndrome. CONCLUSIONS: More than 10% of the men had the MetS both at baseline and after 3 years, and this was associated with an increase in IMT using the WHO definition. Several of the components included in the MetS deteriorated during follow-up, i.e. body mass index (BMI), waist-to-hip ratio (WHR), waist circumference, blood glucose and blood pressure.

Serum matrix metalloproteinase-3 concentration is influenced by MMP-3 -1612 5A/6A promoter genotype and associated with myocardial infarction.

OBJECTIVES: Matrix metalloproteinase-3 (MMP-3) is implicated in the formation of atherosclerotic plaques, and the MMP-3 -1612 5A/6A polymorphism is associated with myocardial infarction (MI) and stable coronary artery disease (CAD). The present study examined whether the -1612 5A/6A polymorphism in the promoter region of the MMP-3 gene influences serum concentrations of MMP-3 and whether serum concentrations of MMP-3 are related to extent of coronary atherosclerosis and risk of MI. DESIGN AND SUBJECTS: This case-control study was conducted in three hospitals in the northern part of Stockholm. A total of 755 MI patients aged below 60 were screened, 433 entered and 387 completed the study. Three hundred and eighty-seven sex- and age-matched control subjects were recruited from the general population of the same county. METHODS: The MMP-3 genotype was determined by Pyrosequencing(TM) and the serum MMP-3 concentration was quantified with an immunoassay. Severity and extension of CAD was assessed by quantitative coronary angiography in a subgroup of patients (n=243). RESULTS: Patients had lower serum MMP-3 concentration than controls. There was a strong association between MMP-3 -1612 5A/6A genotype and serum concentrations of MMP-3. The presence of one or two copies of the 6A-allele was associated with a graded increase in serum MMP-3. In female patients there was an inverse correlation (r=-0.39, P<0.05) between serum MMP-3 concentration and plaque area. Conclusion. In conclusion, the serum concentration of MMP-3 is influenced by MMP-3 -1612 5A/6A genotype and associated with MI.

Circulating oxidized low-density lipoprotein (LDL) is associated with risk factors of the metabolic syndrome and LDL size in clinically healthy 58-year-old men (AIR study).

OBJECTIVES: Hypothetically the atherogenic effect of the metabolic syndrome may be mediated through the increased occurrence of small LDL-particles which are easily modified to atherogenic oxidized LDL (ox-LDL). The aim of this study was to test this concept by examining the association between circulating ox-LDL, LDL-particle size, and the metabolic syndrome. DESIGN AND RESULTS: A population-based sample of clinically healthy 58-year-old men (n = 391) was recruited. Ox-LDL was measured by ELISA (specific monoclonal antibody, mAb-4E6) and LDL-particle size by gradient gel electrophoresis. The results showed that ox-LDL significantly correlated to factors constituting the metabolic syndrome; triglycerides (r = 0.43), plasma insulin (r = 0.20), body mass index (r = 0.20), waist-to-hip ratio (r = 0.21) and HDL (r = -0.24); (P < 0.001). Ox-LDL correlated also to LDL-particle size (r = -0.42), Apo-B (r = 0.70), LDL (r = 0.65); (P < 0.001) and, furthermore, with Apo A-1 (r = -0.13) and heart rate (r = 0.13); (P < 0.01). CONCLUSION: The metabolic syndrome was accompanied by high plasma ox-LDL concentrations compared with those without the syndrome. Ox-LDL levels were associated with most of the risk factors constituting the metabolic syndrome and was, in addition related to small LDL-particle size. To our knowledge the present study is the first one to demonstrate that circulating ox-LDL levels are associated with small LDL-particle size in a population representative sample of clinically healthy middle-aged men. The high degree of intercorrelation amongst several factors makes it difficult to clarify the independent role of any specific factor.

The metabolic syndrome, smoking, and antibodies to oxidized LDL in 58-year-old clinically healthy men.

BACKGROUND AND AIM: The aim was to examine whether the metabolic syndrome (as recently defined), its various components, and smoking were associated with circulating antibodies to oxidized low-density lipoproteins (IgG- and IgM-Ox-LDLAb) and malondialdehyde-treated LDL (IgG- and IgM-MDA-LDLAb) (ELISA) in a population sample of clinically healthy 58-year-old men (n = 391). METHODS AND RESULTS: LDL peak particle size (gradient gel electrophoresis) and antibody titers were measured in all patients. Trend analysis showed significantly higher IgG-Ox-LDLAb and IgG-MDA-LDLAb titers across the range of men with none of the criteria defining metabolic syndrome (n = 77), those with > or = 1 criterion (n = 252) and those fulfilling the criteria (n = 62), which remained after adjustment for smoking. IgG-Ox-LDLAb was associated with plasma insulin, body mass index (BMI), the waist/hip ratio (WHR) and smoking. IgG-MDA-LDLAb was, in addition, related to diastolic blood pressure, serum triglycerides and a small LDL peak particle size. The IgM antibody titers only inversely correlated with smoking. CONCLUSIONS: High serum titers of IgG antibodies to oxidized LDL and MDA-treated LDL were associated with the metabolic syndrome and smoking. Several of the factors in the metabolic syndrome were related to the IgG antibody titers to modified LDL. The high degree of intercorrelation among these factors makes it difficult to clarify the independent role of any specific factor.

Relationship between C-reactive protein and intima-media thickness in the carotid and femoral arteries and to antibodies against oxidized low-density lipoprotein in healthy men: the Atherosclerosis and Insulin Resistance (AIR) study.

Results from several recent reports have linked high serum C-reactive protein (CRP) levels to atherosclerotic disease and its complications. The aims of the present study were to investigate the relationship between CRP levels and subclinical atherosclerosis, as measured by ultrasound in the carotid and femoral arteries; and also to examine whether CRP levels are associated with antibodies to oxidized low-density lipoprotein (Ox-LDL). The study group (n = 391) consisted of clinically healthy 58-year-old men recruited from the general population. CRP and antibody titres to Ox-LDL were measured by ELISA. The results showed an association between CRP and ultrasound-assessed subclinical atherosclerosis in the femoral artery (r = 0.14, P = 0.010), and also between CRP and systolic blood pressure, diastolic blood pressure, heart rate, triglycerides, high-density lipoprotein, body mass index, waist-to-hip ratio (WHR), blood glucose, cigarette-years and antibody titres to ox-LDL (r = 0.19, P < 0.001). In this clinically healthy population of 58-year-old men, CRP levels were associated with both intima-media thickness and plaque occurrence in the femoral artery. The association between CRP and femoral atherosclerosis was not independent of smoking, serum LDL cholesterol, or systolic blood pressure. CRP levels were independently related to abdominal obesity measured as WHR, smoking and antibody titres to Ox-LDL.

Oxidized low-density lipoprotein in plasma is a prognostic marker of subclinical atherosclerosis development in clinically healthy men.

OBJECTIVE: To investigate the association between plasma oxidized low-density lipoprotein (OxLDL) and the progress of clinically silent atherosclerosis, as measured by ultrasound in the carotid arteries. DESIGN: Prospective, observational study with more than 3 years of follow-up. SETTING: One-centre study at university hospital. MATERIAL AND METHODS: The subjects (n = 326) were obtained by stratified sampling from a population sample of men who were 58 years old at baseline. Carotid artery intima-media thickness (IMT) was measured bilaterally by high-resolution B-mode ultrasound at baseline and after follow-up. Plasma OxLDL cholesterol concentrations and conventional cardiovascular risk factors were measured at study entry. Automated measurements of IMT were performed. Plaque occurrence and size were assessed (plaque status). Plasma OxLDL at entry was measured by a specific monoclonal antibody, mAb-4E6. RESULTS: OxLDL at entry, but not LDL cholesterol, was associated with the number and size of plaques at follow-up (P = 0.008), also after adjustment for plaque status at entry (P = 0.033). The plasma OxLDL concentration at entry was associated with change in carotid artery IMT (r = 0.17; P = 0.002) and in a stepwise multiple regression analysis this association remained after adjustment for other cardiovascular risk factors (P = 0.005). CONCLUSIONS: These results provide new information, supporting the concept that circulating OxLDL was associated with the silent phase of atherosclerosis progression in clinically healthy men independently of conventional risk factors.