Impaired protection against diabetes and coronary heart disease by high-density lipoproteins in Turks

A higher dietary inflammatory index score is associated with an increased risk of developing dyslipidemia and its components only in women

The dietary inflammatory index (DII) is a tool to evaluate the inflammatory potential of diets. Our research hypothesized that a higher DII score would be associated with an increased risk of dyslipidemia and that this outcome may differ by sex. Data from the Korean Genome and Epidemiology Study were used. The analysis included participants aged 40 to 69 years from the HEXA study (n = 40,500) and the Ansan-Ansung study (n = 4701). The mean follow-up was 5.03 years for the HEXA study and 8.14 years for the Ansan-Ansung study. The DII scores were calculated based on dietary data. Cox proportional hazards regression analysis was used to calculate hazard ratio (HR) and 95% confidence interval (CI). In pooled analyses, a high DII score was associated with a higher risk of dyslipidemia and its components. Sex-specific analyses revealed associations only in women. A pro-inflammatory diet, as indicated by a higher DII score, was associated with an increased risk of hypercholesterolemia, hyper-low-density lipoprotein cholesterolemia, hypertriglyceridemia, and dyslipidemia, with HR of 1.17 (95% CI: 1.06, 1.29), 1.16 (95% CI: 1.03, 1.29), 1.32 (95% CI: 1.12, 1.52), and 1.17 (95% CI: 1.08, 1.26), respectively. However, among men, there was no association between DII and dyslipidemia. These findings emphasize the inflammation feature of existing dietary patterns in influencing the development of dyslipidemia and related health issues. Further research will be needed to identify the mechanisms of how DII scores affect the risk of dyslipidemia.

Associations of serum apolipoprotein A1, B levels and their ratio with blood pressure in Chinese adults with coronary artery disease

OBJECTIVE

We examined the relationships of apolipoprotein A1 (ApoA1), ApoB levels and ApoB/A1 ratio with blood pressure (BP) in Chinese adults with coronary artery disease (CAD).

METHODS

This cross-sectional study included 4921 adults with CAD. SBP, DBP, serum ApoA1 and ApoB levels were measured. The associations between Apo and BP were assessed by analyses of covariance.

RESULTS

Serum ApoA1 was inversely associated with BP, whereas ApoB and the ApoB/A1 ratio exhibited positive associations with BP. For all subjects, a higher ApoA1 level was associated with lower SBP. Subjects in the fourth quartile for ApoA1 exhibited - 2.85 and - 2.63% lower DBP and mean arterial pressure (MAP), respectively than those in the third quartile. In contrast, higher ApoB and ApoB/A1 ratios were associated with higher SBP, DBP and MAP. The mean differences between ApoB quartiles 4 and 1 were 1.54% for SBP, 2.92% for DBP and 2.29% for MAP. The mean differences between the ApoB/A1 ratio quartiles 4 and 1 were 1.94% for SBP, 3.53% for DBP and 2.80% for MAP. In analyses stratified by gender, graded and inverse associations of ApoA1 with SBP, DBP and MAP were observed in both men and women, but positive associations were observed for ApoB and the ApoB/A1 ratio. Path analysis showed that BMI mediated the associations between ApoB and the ApoB/A1 ratio and SBP.

CONCLUSIONS

In general, serum ApoA1 was inversely associated with BP in persons with CAD. In contrast, serum ApoB and the ApoB/A1 ratio were positively associated with BP, and these associations were mediated by BMI.

Atherogenic index of plasma as predictors for metabolic syndrome, hypertension and diabetes mellitus in Taiwan citizens: a 9-year longitudinal study

Deeply involved with dyslipidemia, cardiovascular disease has becoming the leading cause of mortality since the early twentieth century in the modern world. Whose correlation with metabolic syndrome (MetS), hypertension and type 2 diabetes mellitus (T2DM) has been well established. We conducted a 9-year longitudinal study to identify the association between easily measured lipid parameters, future MetS, hypertension and T2DM by gender and age distribution. Divided into three groups by age (young age: < 40, middle age: ≥ 40 and < 65 and old age: ≥ 65), 7670 participants, receiving standard medical inspection at Tri-Service General Hospital (TSGH) in Taiwan, had been enrolled in this study. Atherogenic index of plasma (AIP) was a logarithmically transformed ratio of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C). Through multivariate regression analyses, the hazard ratio (HR) of AIP for MetS, hypertension and T2DM were illustrated. AIP revealed significant association with all the aforementioned diseases through the entire three models for both genders. Additionally, AIP revealed significant correlation which remained still after fully adjustment in MetS, hypertension, and T2DM groups for subjects aged 40–64-year-old. Nevertheless, for participants aged above 65-year-old, AIP only demonstrated significant association in MetS group. Our results explore the promising value of AIP to determine the high-risk subjects, especially meddle-aged ones, having MetS, hypertension, and T2DM in the present and the future.

Sex-specific associations of TCF7L2 variants with fasting glucose, type 2 diabetes and coronary heart disease among Turkish adults

Objective:

TCF7L2 is a repressor and transactivator of genes, and its variants are strongly associated with diabetes. This study aimed to evaluate the sex-specific relationship between the most common TCF7L2 gene variants (-98368G>T, rs12255372 and -47833C>T, rs7903146) with diabetes and coronary heart disease in Turkish Adult Risk Factor (TARF) Study.

Methods:

Single nucleotide variants (SNVs) have been genotyped using the TaqMan allelic discrimination assays in 2,024 (51.3% in women, age: 55±11.8) Turkish adults participating in the TARF study. Statistical analyses were used to investigate the association of genotypes with clinical and biochemical measurements.

Results:

Among the TARF study participants, 11.7%, 24.3%, 14.1%, and 38.3% had diabetes, hypertension, coronary heart disease (CHD), and obesity, respectively. The frequencies of T allele for -47833C>T and -98368G>T in Turkish adults were determined to be 0.35 and 0.33, respectively. -47833C>T was significantly associated with higher fasting glucose concentrations in all participants, especially in men. Both SNVs were significantly associated with diabetes and CHD in all participants (p<0.05). When study population was stratified according to sex, -98368G>T was associated with diabetes in women (p=0.041) and -47833C>T was associated with diabetes and CHD in men (p=0.018 and p=0.032, respectively). Also, both SNVs and the diplotypes of common haplotype (H1) remained strongly associated with type 2 diabetes after risk factors were adjusted (p<0.05).

Conclusion:

T allele homozygosity of two SNVs as well as the diplotype H1-/H1- reflects risk of diabetes primarily in men. Enhanced CHD risk is determined by the presence of diplotype H1-/H1- among nondiabetic participants.

Modified risk associations of lipoproteins and apolipoproteins by chronic low-grade inflammation

INTRODUCTION

Lipoproteins and the apolipoproteins (apo) that they carry are major determinants of cardiovascular diseases (CVD) as well as metabolic, renal and inflammatory chronic disorders either directly or through mediation of risk factors. The notion that elevated low-density lipoprotein cholesterol (LDL-C) and apoB levels are related to the acquisition of CVD and, high-density lipoprotein cholesterol (HDL-C) and apoA-I indicate protection against CVD has been challenged in the past decade. Advanced age, adiposity, ethnicity or impaired glucose intolerance rendered autoimmune activation in an environment of pro-inflammatory state/oxidative stress and may disrupt the linear risk association between lipoproteins. Areas covered: This review summarizes the modified risk associations of lipoproteins and apolipoprotein by an environment of chronic systemic low-grade inflammation with special emphasis on the non-linear relationship of lipoprotein(a) [Lp(a)], a biomarker of renewed interest in cardiometabolic risk. Expert commentary: It seems that autoimmune activation in an environment of pro-inflammatory state/oxidative stress not only disrupts the linear risk association between lipoproteins, but also may cause interference in immunoassays. Hence, methodological improvement in immunoassays and much further research focusing on population segments susceptible to a pro-inflammatory state is necessary for further advances in knowledge.

Algorithm for predicting CHD death risk in Turkish adults: conventional factors contribute only moderately in women

OBJECTIVE

To assist the management strategy of individuals, we determined an algorithm for predicting the risk of coronary heart disease (CHD) death in Turkish adults with a high prevalence of metabolic syndrome (MetS).

METHODS

The risk of CHD death was estimated in 3054 middle-aged adults, followed over 9.08±4.2 years. Cox proportional hazard regression was used to predict risk. Discrimination was assessed using C-statistics.

RESULTS

CHD death was identified in 233 subjects. In multivariable analysis, the serum high-density lipoprotein-cholesterol (HDL-C) level was not predictive in men and the non-HDL-C level was not predictive in women. Age, presence of diabetes, systolic blood pressure ≥160 mm Hg, smoking habit, and low physical activity were predictors in both sexes. The exclusion of coronary disease at baseline did not change the risk estimates materially. Using an algorithm of the 7 stated variables, individuals in the highest category of risk score showed a 19- to 50-fold higher spread in the absolute risk of death from CHD than those in the second lowest category. C-index of the model using age alone was as high as 0.774 in men and 0.836 in women (p<0.001 each), while the incorporation of 6 conventional risk factors contributed to a C-index of 0.058 in males and 0.042 in females.

CONCLUSION

In a middle-aged population with prevalent MetS, men disclosed anticipated risk parameters (except for high HDL-C levels) as determinants of the risk of CHD death. On the other hand, serum non-HDL-C levels and moderate systolic hypertension were not relevant in women. The moderate contribution of conventional risk factors (beyond age) to the estimation of the risk of CHD death in women is consistent with the operation of autoimmune activation.

Little contribution of conventional factors in an algorithm to predicting death risk in Turkish adults

OBJECTIVE

Determinants of risk of death are highly relevant for the management strategy of individuals. We aimed to determine an algorithm for predicting risk of death in Turkish adults who have a high prevalence of metabolic syndrome (MetS).

METHODS

Nine-year risk of death was estimated in 3348 middle-aged adults, followed over 8.81±4.2years. Cox proportional hazard regression was used to predict risk of death. Discrimination was assessed using C-statistics.

RESULTS

Death occurred in 565 subjects. In multivariable analysis, high-density lipoprotein (HDL) and non-HDL cholesterol levels were not predictive in either sex; in women, current smoking was also not predictive. Age, presence of diabetes, systolic blood pressure ≥160mmHg and low physical activity were predictors in both sexes, beyond smoking status in men. Exclusion of coronary disease at baseline did not change risk estimates materially. Using an algorithm of the stated 7 variables showed an 11- to 18-fold spread in the absolute risk of dying among individuals in the highest than in the lowest of 4 risk score categories. C-statistics of the model using age alone was 0.790 in men, 0.808 in women (p<0.001 each), while the incorporation of 6 conventional risk factors contributed to C-index was >0.020 in males and 0.009 in females.

CONCLUSIONS

In a middle-aged population with prevalent MetS, serum lipoproteins and, in women, smoking status, were not relevant for the risk of death. The contribution of conventional risk factors beyond age to estimating risk of death was modest among Turkish men, and little in women in whom autoimmune activation is operative.

Advances in understanding gender difference in cardiometabolic disease risk

Gender differences exist in cardiovascular or metabolic disease risk, beyond the protective effect of estrogens, mostly burdening the postmenopausal female. We aimed to review herein sex differences in pro-inflammatory states, the independence of inflammation from insulin resistance, differences in high-density lipoprotein dysfunction, in gene-environment interactions, and in the influence of current and former smoking on cardiometabolic risk. Sex differences in absorption of long-chain fatty acids are highlighted. Differences exist in the first manifestation of cardiovascular disease, men being more likely to develop coronary heart disease as a first event, compared to women who have cerebrovascular disease or heart failure as a first event. Autoimmune activation resulting from pro-inflammatory states, a fundamental mechanism for numerous chronic diseases in people prone to metabolic syndrome, is much more common in women, and these constitute major determinants. Therapeutic approaches to aspects related to sex difference are briefly reviewed.

Apolipoprotein-A1 as a damage-associated molecular patterns protein in osteoarthritis: ex vivo and in vitro pro-inflammatory properties

Osteoarthritis (OA) is associated with a local inflammatory process. Dyslipidemia is known to be an underlying cause for the development of OA. Therefore, lipid and inflammatory levels were quantified ex vivo in blood and synovial fluid of OA patients (n=29) and compared to those of rheumatoid arthritis (RA) patients (n=27) or healthy volunteers (HV) (n=35). The role of apolipoprotein A-I (ApoA1) was investigated in vitro on inflammatory parameters using human joint cells isolated from cartilage and synovial membrane obtained from OA patients after joint replacement. Cells were stimulated with ApoA1 in the presence or not of serum amyloid A (SAA) protein and/or lipoproteins (LDL and HDL) at physiological concentration observed in OA synovial fluid. In our ex vivo study, ApoA1, LDL-C and total cholesterol levels were strongly correlated to each other inside the OA joint cavity whereas same levels were not or weakly correlated to their corresponding serum levels. In OA synovial fluid, ApoA1 was not as strongly correlated to HDL as observed in OA serum or in RA synovial fluid, suggesting a dissociative level between ApoA1 and HDL in OA synovial fluid. In vitro, ApoA1 induced IL-6, MMP-1 and MMP-3 expression by primary chondrocytes and fibroblast-like synoviocytes through TLR4 receptor. HDL and LDL attenuated joint inflammatory response induced by ApoA1 and SAA in a ratio dependent manner. In conclusion, a dysregulated lipidic profile in the synovial fluid of OA patients was observed and was correlated with inflammatory parameters in the OA joint cavity. Pro-inflammatory properties of ApoA1 were confirmed in vitro.

High-density lipoprotein oxidation in type 2 diabetic patients and young patients with premature myocardial infarction

BACKGROUND AND AIMS

ApoA-I can undergo oxidative changes that reduce anti-atherogenic role of HDL. The aim of this study was to seek any significant differences in methionine sulfoxide (MetO) content in the ApoA-I of HDL isolated from young patients with coronary heart disease (CHD), type 2 diabetics and healthy subjects.

METHODS AND RESULTS

We evaluated the lipid profile of 21 type 2 diabetic patients, 23 young patients with premature MI and 21 healthy volunteers; we determined in all patients the MetO content of ApoA-I in by MALDI/TOF/TOF technique. The typical MALDI spectra of the tryptic digest obtained from HDL plasma fractions all patients showed a relative abundance of peptides containing Met(112)O in ApoA-I in type 2 diabetic and CHD patients. This relative abundance is given as percentages of oxidized ApoA-I (OxApoA-I). OxApoA-I showed no significant correlations with lipoproteins in all patients studied, while a strong correlation emerged between the duration of diabetic disease and OxApoA-I levels in type 2 diabetic patients.

CONCLUSIONS

The most remarkable finding of our study lies in the evidence it produced of an increased HDL oxidation in patients highly susceptible to CHD. Levels of MetO residues in plasma ApoA-I, measured using an accurate, specific method, should be investigated and considered in prospective future studies to assess their role in CHD.

Normal thyroid-stimulating hormone levels, autoimmune activation, and coronary heart disease risk

Whether euthyroid status affects cardiovascular disease risk is unclear. We aimed to investigate whether serum thyroid-stimulating hormone (TSH) levels within the normal range are related to the risk of coronary heart disease (CHD). In participants of the Turkish Adult Risk Factor Study (mean age 52.7±11.5), in whom TSH was measured in the 2004/05 survey, cross-sectional and longitudinal analyses were performed. Subjects with TSH concentrations<0.3 and >4.2 mIU/L were excluded to ensure euthyroid status leaving 956 individuals as the study sample. Mean follow-up was 4.81±1.3 years. Men had 18% lower (p<0.001) geometric mean TSH levels (1.10 mIU/L) than women (1.35 mIU/L). Correlations of TSH with risk variables were notably virtually absent except weakly positive ones in men with age and systolic blood pressure (SBP). The age-adjusted TSH mid-tertile in men was associated with lowest lipoprotein [Lp](a), apoB, and total cholesterol values. Incident CHD was predicted in Cox regression analyses in men [HR of 2.45 (95 %CI 1.05; 5.74] and in combined sexes by the lowest compared with the highest TSH tertile, after adjustment for age, smoking status, SBP, and LDL-cholesterol. Analysis for combined prevalent and incident CHD stratified by metabolic syndrome (MetS) confirmed the independent association with the lowest TSH tertile in men, specifically in men without MetS. TSH levels within normal range, low due to partial assay failure, may manifest as independent predictors of incident CHD, particularly in middle-aged men. Autoimmune responses involving serum Lp(a) under oxidative stress might be implicated mechanistically.

Type-2 diabetes and coronary heart disease: common physiopathology, viewed from autoimmunity

Two highly prevalent diseases, Type-2 diabetes mellitus and coronary heart disease (CHD), share risk factors. Excess levels of LDL-cholesterol have been overemphasized to uniformly encompass the development of CHD, and the origin of insulin resistance underlying Type-2 diabetes has not been fully elucidated. Autoimmune response has been recognized to be responsible only of a small minority of diabetes. The increasing trend in the worldwide prevalence of diabetes and the risk factors for both diseases are reviewed, the independent mediation for CHD of (central) adiposity in both diseases and the 'hypertriglyceridemic waist' phenotype are outlined. Evidence is described that serum lipoprotein (Lp)(a) concentrations, not only in excess, but also in apparently 'reduced' levels, as a result of autoimmune response, underlie both disorders and are closely related to insulin resistance.

Atherosclerosis: process, indicators, risk factors and new hopes

Background:

Atherosclerosis is the major cause of morbidities and mortalities worldwide. In this study we aimed to review the mechanism of atherosclerosis and its risk factors, focusing on new findings in atherosclerosis markers and its risk factors. Furthermore, the role of antioxidants and medicinal herbs in atherosclerosis and endothelial damage has been discussed and a list of important medicinal plants effective in the treatment and prevention of hyperlipidemia and atherosclerosis is presented.

Methods:

The recently published papers about atherosclerosis pathogenesis and herbal medicines effective in the treatment and prevention of hyperlipidemia and atherosclerosis were searched.

Results:

Inflammation has a crucial role in pathogenesis of atherosclerosis. The disease is accompanied by excessive fibrosis of the intima, fatty plaques formation, proliferation of smooth muscle cells, and migration of a group of cells such as monocytes, T cells, and platelets which are formed in response to inflammation. The oxidation of low density lipoprotein (LDL) to Ox-LDL indicates the first step of atherosclerosis in cardiovascular diseases. Malondialdehyde factor shows the level of lipoperoxidation and is a sign of increased oxidative pressure and cardiovascular diseases. In special pathological conditions such as severe hypercholesterolemia, peroxynitrite concentration increases and atherosclerosis and vascular damage are intensified. Medicinal plants have shown to be capable of interacting these or other pathogenesis factors to prevent atherosclerosis.

Conclusions:

The pathogenesis factors involved in atherosclerosis have recently been cleared and the discovery of these factors has brought about new hopes for better prevention and treatment of atherosclerosis.

Novel metabolic biomarkers of cardiovascular disease

Coronary heart disease (CHD) accounts for one in every six deaths in US individuals. Great advances have been made in identifying important risk factors for CHD, such as hypertension, diabetes mellitus, smoking and hypercholesterolaemia, which have led to major developments in therapy. In particular, statins represent one of the greatest successes in the prevention of CHD. While these standard risk factors are important, an obvious opportunity exists to take advantage of ongoing scientific research to better risk-stratify individuals and to identify new treatment targets. In this Review, we summarize ongoing scientific research in a number of metabolic molecules or features, including lipoproteins, homocysteine, calcium metabolism and glycaemic markers. We evaluate the current state of the research and the strength of evidence supporting each emerging biomarker. We also discuss whether the associations with CHD are strong and consistent enough to improve current risk stratification metrics, and whether these markers enhance our understanding of the underlying biology of CHD and thus point towards new treatment options.

Association of Elevated Serum Uric Acid with the Components of Metabolic Syndrome and Oxidative Stress in Abdominal Obesity Subjects

Abdominal obesity (AO) and metabolic syndrome (MetS) are associated with the cardiovascular disease and type 2 diabetes. Serum uric acid (SUA) is often elevated in subjects with the AO. We aimed to investigate the association of elevated SUA with the components of MetS, oxidative stress and TG/HDL-C ratio in AO subjects. This cross-sectional study used data from a Health Survey for Prevention of Hypertension and Type 2 Diabetes Mellitus in residents of two districts in Phitsanulok province, including 443 subjects. Anthropometric, blood pressure (BP) and biochemical variables were measured. We categorized the participants to two-group as 248 AO subjects (median age = 58, interquartile range 50.0-65.0 years) and 195 non-AO subjects (median age = 53, interquartile range 47.0-62.0 years). Waist circumference was significantly correlated with SystBP, DiastBP, Glu and SUA (P < 0.05) and SUA was significantly correlated with Glu, TG, HDL-C and TG/HDL-C ratio (P < 0.05). By using multiple logistic regression, we found the association of elevated SUA with abdominal obesity, hyperglycemia, hypertriglyceridemia, reduced HDL-C, elevated TG/HDL-C ratio, MetS and increased oxidative stress after adjusting for their covariates. Our study demonstrated that circulating UA is a major antioxidant and might help protect against free-radical oxidative damage. However, elevated SUA concentrations associated with oxidative stress, MetS, insulin resistance, and components of MetS. Then, SUA may be a marker of increased oxidative stress, insulin resistance and MetS, implying an increased risk of vascular disease and T2DM.

Abdominal obesity with hypertriglyceridaemia, lipoprotein(a) and apolipoprotein A-I determine marked cardiometabolic risk

BACKGROUND

Risks for coronary heart disease (CHD) and diabetes (T2DM) of the 'hypertriglyceridemic waist' phenotype (HtgW) warrant further investigation. We studied this issue and whether partial proinflammatory conversion of apolipoprotein (apo) A-I by lipoprotein(a) [Lp(a)] is a codeterminant.

MATERIALS AND METHODS

In a population-based prospective study, 1328 Turkish adults were analysed in four groups by the presence of abdominal obesity and elevated triglycerides (Htg).

RESULTS

LDL-cholesterol levels, significantly elevated in isolated Htg, were lower in HtgW, yet significantly higher apoB and complement C3 values existed in women with HtgW in whom also the lowest Lp(a) values prevailed. Lp(a) was linearly associated, more strongly in HtgW than in the remaining groups, with apoB and, in women inversely, with gamma-glutamyltransferase. Incident HtgW was predicted, not in men, but in women inversely by Lp(a) (OR 0.80 [95%CI 0.65; 0.97]), regardless of adjustment for relevant confounders. After adjustment for conventional risk factors, HtgW (OR 2.84) and high apoA-I/HDL-C ratio (OR 1.50) were significantly and additively associated with combined prevalent and incident CHD risk. High apoA-I and low HDL-cholesterol levels interacted therein in women. Type-2 diabetes was strongly predicted by HtgW, mediated in men by high apoA-I/HDL-C ratio.

CONCLUSION

HtgW is associated with excess inflammatory markers, is predicted in women paradoxically by lower circulating Lp(a) and is associated in both sexes with marked excess cardiometabolic risk to which high apoA-I/HDL-C ratio contributes additively. These findings are consistent in women with apoA-I being oxidized via aggregation to Lp(a).

Impaired fasting glucose: Pro-diabetic, “atheroprotective” and modified by metabolic syndrome

AIM: To investigate whether impaired fasting glucose (IFG) confers cardiovascular risk.

METHODS: A non-diabetic population-based sample representative of middle-aged and elderly Turks was studied at 8.5 years’ follow-up for incident diabetes and coronary heart disease (CHD). Metabolic syndrome (MetS) was defined by ATP-III criteria modified for male abdominal obesity, and IFG and type 2 diabetes were identified by criteria of the American Diabetes Association. Stratification by presence of MetS was used. Outcomes were predicted providing estimates for hazard ratio (HR) obtained by use of Cox proportional hazards regression analysis in models that controlled for potential confounders.

RESULTS: In 3181 adults (aged 52 ± 11.5 years at baseline), analysis stratified by MetS, gender and IFG status distinguished normoglycemic subjects by a “hypertriglyceridemic waist” phenotype consisting of significantly higher waist circumference, fasting triglyceride and lower high-density lipoprotein-cholesterol, regardless of gender and MetS. Additionally, lipoprotein (Lp) (a) tended to be lower in (especially female) participants with MetS. Multivariable linear regression in a subset of the sample demonstrated decreased Lp (a) levels to be associated with increased fasting glucose and insulin concentrations, again particularly in women. In Cox regression analysis, compared with normoglycemia, baseline IFG adjusted for major confounders significantly predicted incident diabetes at a 3-fold HR in men and only women with MetS. Cox models for developing CHD in 339 individuals, adjusted for conventional risk factors, revealed that IFG status protected against CHD risk [HR = 0.37 (95%CI: 0.14-0.998)] in subjects free of MetS, a protection that attenuated partly in male and fully in female participants with MetS.

CONCLUSION: IFG status in non-diabetic people without MetS displays reduced future CHD risk, yet is modulated by MetS, likely due to autoimmune activation linked to serum Lp (a).

Elevated serum uric acid in nondiabetic people mark pro-inflammatory state and HDL dysfunction and independently predicts coronary disease

We explored the association of serum uric acid (UA) concentrations with pro-inflammatory state and high-density lipoprotein (HDL) dysfunction. UA tertiles in tracked 1,508 nondiabetic participants were analyzed cross-sectionally for associations with inflammation biomarkers and protective proteins over a mean follow-up of 4.9 years for incident coronary heart disease (CHD) using Cox proportional hazards regression. In the absence of metabolic syndrome (MetS), UA tertiles significantly distinguished, in each sex, increasing categories of three MetS components (inflammation/oxidation markers, apolipoprotein (apo)B) and (inversely) current smoking (but not protective proteins such as HDL, apoA-I, and adiponectin). Distinctions attenuated in the presence of MetS. Linear regression model revealed fasting triglycerides (1.86 mg/dl variance), male sex, and gamma-glutamyl transferase and age as covariates of UA levels in women. In Cox analysis, incident CHD (n = 137) was predicted by mid and upper UA tertile in men alone at significant hazard ratios of 2.7, additively to conventional risk factors. Elevated serum UA levels, linked to triglycerides, mark in nondiabetic people pro-inflammatory state, and, notably, HDL dysfunction. CHD risk is independently predicted by elevated UA levels in nondiabetic men and is modulated by MetS and gender.

Fasting, non-fasting glucose and HDL dysfunction in risk of pre-diabetes, diabetes, and coronary disease in non-diabetic adults

We determined in non-diabetic persons the risk of fasting and non-fasting glucose levels for pre-diabetes, diabetes, and coronary heart disease (CHD), including the roles of serum C-reactive protein (CRP) and HDL cholesterol, and delineated risk profiles of the pre-diabetic states. Over 7¼ years, 2,619 middle-aged Turkish adults free of diabetes and CHD were studied prospectively. Using different serum glucose categories including impaired fasting glucose (IFG, 6.1-6.97 mmol/L) and impaired glucose tolerance (IGT), outcomes were analyzed by Cox regression. IFG was identified at baseline in 112 and IGT in 33 participants. Metabolic syndrome components distinguished individuals with IFG from those with normoglycemia. Participants with IGT tended to differ from adults in normal postprandial glucose categories in regard to high levels of triglycerides, apoA-I, and CRP. Diabetes risk, adjusted for sex, age, waist circumference, CRP, and HDL cholesterol, commenced at a fasting 5.6-6.1 mmol/L threshold, was fourfold at levels 6.1-6.97 mmol/L. Optimal glucose values regarding CHD risk were 5.0-6.1 mmol/L. Fasting and postprandial glucose values were not related to CHD risk in men; IGT alone predicted risk in women (HR 3.74 [1.16;12.0]), independent of age, systolic blood pressure, non-HDL cholesterol, waist circumference, smoking status, and CRP. HDL cholesterol was unrelated to the development of IFG, IGT, and diabetes, while CRP elevation independently predicted the development of diabetes. IGT independently predicts CHD risk, especially in women. HDL dysfunction associated with low-grade inflammation is a co-determinant of pre-diabetic states and their progression to diabetes.

The value of apolipoprotein B/A1 ratio in the diagnosis of metabolic syndrome in a Korean population

OBJECTIVE

The ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1) has been reported to be associated with the metabolic syndrome (MetS). However, the optimal cut-off value of apoB/A1 ratio for detecting subjects with MetS has remained undetermined. In the present study, we aimed to investigate whether apoB/A1 ratio can be an indicator of MetS and to determine the optimal cut-off value of apoB/A1 ratio in detecting subjects with MetS in a Korean population.

DESIGN

This cross-sectional study was conducted at the Asan Medical Center, Seoul, Republic of Korea.

SUBJECTS AND MEASUREMENTS

We collected the data of 10,940 subjects who participated in a routine health screening examination regarding conventional risk factors and serum levels of apoB and apoA1.

RESULTS

The odds for MetS were significantly higher in the highest compared with the lowest apoB/A1 ratio quartiles, after adjustment for confounding variables, in both men [odds ratio (OR) = 4·07, 95% CI = 3·42-4·84] and women (OR = 8·41, 95% CI = 5·85-12·08). The optimal apoB/A1 ratio cut-off value for the detection of MetS was 0·65, which had a sensitivity of 63·5% and a specificity of 61·3% (area under the curve = 0·67, 95% CI = 0·66-0·68, P < 0·001) in men and 0·62, which had a sensitivity of 67·9% and a specificity of 61·9% (area under the curve = 0·70, 95% CI = 0·69-0·71, P < 0·001) in women.

CONCLUSIONS

These results suggest that apoB/A1 ratio is independently associated with MetS and that an apoB/A1 ratio >0·65 in men and 0·62 in women is a marker of MetS independent from conventional risk factors.

High serum apolipoprotein E determines hypertriglyceridemic dyslipidemias, coronary disease and apoA-I dysfunctionality

The relevance of serum apolipoprotein E (apoE) levels to two hypertriglyceridemic dyslipidemias has not been clarified. We explored, in a cross-sectional (and short-term prospective) evaluation, the independent relationship of serum apoE to the atherogenic dyslipidemia, hypertriglyceridemia with elevated apoB (HtgB) and to apoA-I dysfunctionality, previously shown in Turkish adults to be independent of apoE genotype. Serum apoE concentrations were measured by immunonephelometry in 1,127 middle-aged adults. In multivariable regression analysis, apoE concentrations showed log-linear associations with apoB and apoA-I levels, waist circumference, independent of C-reactive protein (CRP), homeostatic model assessment (HOMA) index and other confounders. The likelihood of atherogenic dyslipidemia and of HtgB roughly tripled per 1-SD increment in apoE concentrations, additively to apoE genotype, HOMA, apoA-I, CRP concentrations and waist circumference; yet apoA-I, protective against atherogenic dyslipidemia, appeared to promote HtgB, a finding consistent with apoA-I dysfunctionality in this setting. Each 1-SD increment in the apoE level was moreover, associated in both genders with MetS (at OR 1.5), after adjustment for sex, age, apoB, apoA-I and CRP, or for apoE genotypes. Circulating apoE predicted in both genders age-adjusted prevalent and incident coronary heart disease (CHD), independent of apoE genotype and CRP (OR 1.32 [95 % CI 1.11; 1.58]). To conclude, in a general population prone to MetS, elevated apoE concentrations are strongly linked to HtgB and atherogenic dyslipidemia, irrespective of apoE genotype, are associated with MetS and CHD. Excess apoE reflects pro-inflammatory state and likely autoimmune activation.

Coronary disease risk prediction algorithm warranting incorporation of C-reactive protein in Turkish adults, manifesting sex difference

BACKGROUND AND AIM

An algorithm is needed for predicting coronary heart disease (CHD) risk in Turkish adults who have a high prevalence of metabolic syndrome (MetS).

METHODS AND RESULTS

Ten-year risk of CHD was estimated in 2232 middle-aged adults free of CHD at baseline, followed over 7.6-years. Cox proportional hazard regression was used to predict CHD. Discrimination was assessed with area under receiver operating characteristics curve (AROC). CHD developed in 302 subjects. In multivariable analysis, high-density lipoprotein (HDL)-cholesterol levels were borderline predictive in men; smoking status and HDL-and low-density lipoprotein (LDL)-cholesterol levels were not predictive in women. Age, presence of diabetes, systolic blood pressure and C-reactive protein (CRP) were predictors in both sexes, while smoking status and LDL-cholesterol were so in men only. AROC of the model was 0.789 in men, and 0.806 in women (p < 0.001 each). An algorithm using the stated seven variables was derived separately for each sex. After age adjustment, men and women in the highest quintile of risk score were significantly and 20-27-fold more likely to develop CHD than those in the lowest quintile.

CONCLUSIONS

In a population with prevalent MetS, low-grade inflammation is independently relevant for CHD, as are serum lipoproteins and smoking status. The derived algorithm is effective in estimating CHD risk among Turkish adults.

Metabolic syndrome: nature, therapeutic solutions and options

INTRODUCTION

Metabolic syndrome (MetS) defines the clustering in an individual of multiple metabolic abnormalities, based on central obesity and insulin resistance. In addition to its five components, prothrombotic and proinflammatory states are essential features. The significance of MetS lies in its close association with the risk of type 2 diabetes and cardiovascular disease (CVD). This field being an evolving one necessitated the current review.

AREAS COVERED

The areas covered in this review include the so far unproven concept that enhanced low-grade inflammation often leads to dysfunction of the anti-inflammatory and atheroprotective properties of apolipoprotein A-I (apoA-I) and HDL particles, which further increases the risk of diabetes and CVD. It was emphasized that lifestyle modification is essential in the prevention and management of MetS, which includes maintenance of optimal weight by caloric restriction, adherence to a diet that minimizes postprandial glucose and triglyceride fluctuations, restricting alcohol consumption, smoking cessation and engaging in regular exercise. Drug therapy should target the dyslipoproteinemia and the often associated hypertension or dysglycemia.Statins are the drugs of first choice, to be initiated in patients with MetS at high 10-year cardiovascular risk. Such treatment is inadequate if fasting serum triglycerides remain at > 150 mg/dl, when niacin should be combined. Fibrates, omega 3 fatty acids, metformin, angiotensin-converting enzyme inhibitors and pioglitazone are additional options in drug therapy.

EXPERT OPINION

Research on MetS in subpopulations prone to impaired glucose tolerance and insulin resistance has indicated that proinflammatory state and oxidative stress are often prominently involved in MetS, to the extent that evidence of impaired function of HDL and apo A-I particles is discernible by biological evidence of functional defectiveness via outcomes studies and/or correlations with inflammatory and anti-inflammatory biomarkers. A sex difference has been clear in this development.

Dual activity of serum lipoprotein-associated phospholipase A(2) yielding positive and inverse associations with cardiometabolic risk

BACKGROUND

The clinical relevance of serum lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) in populations prone to cardiometabolic risk needs exploration. We determined major covariates of Lp-PLA(2) mass, and its associations with cardiometabolic disorders.

METHODS

In 736 Turkish adults, serum total Lp-PLA(2) mass was determined by immunoassay. Its association with cardiometabolic risk was assessed in three categories. In a second sample of 98 subjects, enzyme protein in high-density lipoprotein (HDL) was also assayed after precipitation.

RESULTS

Significant inverse correlation existed with high triglyceride/low HDL cholesterol dyslipidemia, waist girth, apolipoprotein C-III, homeostatic model assessment, and linear inverse associations in women with lipoprotein (a) and fibrinogen, suggesting that Lp-PLA(2) mass reflected insulin sensitivity and that HDL bound enzyme mass dominated the associations. Among men, positive linear association with total cholesterol suggested additional association with low-density lipoprotein (LDL)-bound enzyme. High (>450 ng/mL) opposed to low (<210 ng/mL) circulating Lp-PLA(2) mass was associated with prevalent and incident coronary heart disease (CHD) in men. One SD increment in Lp-PLA(2) was associated with a 1.64-fold (95% CI 1.00; 2.70) likelihood of CHD, after adjustment for potential confounders. Furthermore, Lp-PLA(2) categories were significantly, independently and inversely associated in men with diabetes only (OR 0.61) and in women with metabolic syndrome only (OR 0.68), for a 1-SD increment.

CONCLUSIONS

Serum total Lp-PLA(2) mass may indicate either elevated or diminished cardiometabolic risk, specific for gender, depending on its partitioning in lipoprotein groups.

Low-grade inflammation, and dysfunction of high-density lipoprotein and its apolipoproteins as a major driver of cardiometabolic risk

Dysfunction of high-density lipoprotein (HDL) particles that even become proinflammatory or lose atheroprotective properties is known through analyses of HDL isolated from diabetic subjects. Recently, high concentrations of HDL or apolipoprotein (apo) A-I in individuals with diabetes or coronary heart disease were found to reveal dysfunction in some population-based studies. Such dysfunction of HDL and its apos A-I, A-II, and C-III has been observed in a general population for the first time among Turkish adults. Functional defectiveness manifested itself by unexpected correlations with inflammatory biomarkers and, in long-term follow-up, by lack of protection against diabetes and coronary heart disease, accounting for the excess incidences in Turks. Female sex was more pronouncedly affected by this process that presumably exists in other ethnicities in South Asia, East Europe, and the Middle East. In contradistinction, in Western and East Asian population, only individuals with glucose intolerance or those at risk for cardiometabolic disease are considered to be or were documented in a review of clinical trials to have been affected by impaired function of HDL. High-density lipoprotein dysfunctionality is closely linked to obesity and low-grade inflammation yet seems to act partly independently of them. Cigarette smoking in overweight women with low-grade inflammation appears to offer limited protection against cardiometabolic risk. The great impact in public health of the dysfunction of protective serum proteins requires individual clinical recognition, appropriate preventive measures, and delineation of management, including with anti-inflammatory drugs.

Complement C3 and cleavage products in cardiometabolic risk

This review summarizes available evidence on the role of serum complement component 3 (C3), produced by liver, adipocytes and activated macrophages at inflammation sites, and C3 cleavage products linking lipoproteins and metabolism to immunity. C3 and cleavage products are modified in several associated metabolic disorders including obesity, insulin resistance, type-2 diabetes, dyslipidemia, and cardiovascular diseases. Circulating C3 is independently and linearly associated with serum triglycerides, C-reactive protein (CRP), waist circumference and in some populations inversely with current smoking. The complement cascade is activated during myocardial ischemia and likely mediates immune and inflammatory responses in ischemic myocardium. Serum complement activation is elevated in unstable rather than stable angina pectoris suggesting added contribution to damage extension in acute coronary syndromes. In logistic regression models for incident metabolic syndrome (MetS), increasing C3 concentrations predicted MetS in women, after adjusting for continuous values of 3 major MetS components and other confounders, with a relative risk similar in magnitude to an established component suggesting elevated C3 likely constitutes part of the cluster of MetS in women. C3 interacts with MetS in men for independently conferring risk of incident type-2 diabetes and coronary heart disease (CHD). In women, though C3 is equally predictive of cardiometabolic risk, it is less so additively to MetS components or to CRP. Evidence suggests that circulating C3 might serve as a signal for an immune process that enhances - via mediation of increased apolipoprotein (apo) E levels - the development of dysfunctional apoA-I particles rendering them diabetogenic and atherogenic in populations prone to MetS or subsets of populations harboring impaired glucose tolerance. C3 activation also leads to production of chemoattractants C3a and C5a, and acylation stimulating protein (ASP, C3adesArg), a lipogenic hormone, which contribute additionally to the metabolic phenotypes generated. These observations have clinical and public health implications.

Serum complement C3: a determinant of cardiometabolic risk, additive to the metabolic syndrome, in middle-aged population

We studied whether serum complement C3 (C3) is an independent determinant of incident cardiometabolic risk (coronary heart disease [CHD], metabolic syndrome [MetS], and type 2 diabetes mellitus). A cohort of 1220 adults of a general population (age, 53 +/- 10.5 years) was evaluated prospectively at 3.3 years follow-up using Cox proportional hazard regressions. Cardiometabolic risk factors were measured. Metabolic syndrome was identified by Adult Treatment Panel III criteria modified for male abdominal obesity. The C3 levels were associated significantly and linearly with serum triglycerides, waist circumference, and C-reactive protein (CRP), and inversely with current smoking but not with the marker of insulin resistance. In regression models for incident MetS, increasing C3 quartiles strongly predicted MetS in women and in both sexes combined after adjusting for all 5 MetS components and other confounders. Circulating C3 significantly predicted in each sex incident CHD independent of age, smoking status, and presence of MetS. Even after entering CRP, C3 predicted CHD with a relative risk of 1.35 (95% confidence interval, 1.09-1.67) for 1-SD increment of C3 in the total sample. Complement C3 tended to contribute, additively to MetS, to the association with diabetes with a relative risk of 1.36 in women alone, not in men. In conclusion, elevated serum complement C3 is part of the MetS cluster and confers CHD risk, additively to MetS components and CRP, in a population in which MetS prevails. Levels contribute, additively to MetS, to the diabetes risk in women alone.

"Atherogenic index of plasma" (log10 triglyceride/high-density lipoprotein-cholesterol) predicts high blood pressure, diabetes, and vascular events

OBJECTIVES

To determine the association of atherogenic index of plasma (AIP), the logarithm of molar ratio of triglyceridemia to high-density lipoprotein cholesterol (TG/HDL-cholesterol) with cardiometabolic disorders was investigated in a sample of the Turkish population.

METHODS

A total of 2676 middle-aged adults were prospectively evaluated with a clinical examination and laboratory tests during 7.8 years' follow-up.

RESULTS

AIP was significantly associated in multiple linear regression analyses with greater apolipoprotein B and lower low-density lipoprotein (LDL)-cholesterol levels, reflecting the presence of smaller LDL particle size. Whereas in men insulin levels, obesity, and nonHDL-cholesterol were major determinants, C-reactive protein (CRP) was the strongest determinant of AIP among women, independent of body mass index. Top quartiles of AIP predicted significantly age-adjusted incident coronary heart disease (CHD) in both sexes, more strongly in women, in whom quartile 3 also was a predictor with a greater than 2-fold relative risk. Associations remained significant after adjustment for CRP and traditional risk factors. AIP significantly predicted diabetes and high blood pressure in both sexes after adjustment for age and CRP. With regard to incident high blood pressure, the risk ratio in men was attenuated when body mass index also was adjusted.

CONCLUSIONS

High AIP, a surrogate of small LDL particle size, reflects obesity and hyperinsulinemia in men and high CRP status in women. It predicts CHD independently, type 2 diabetes mediated by obesity in men and in women, high blood pressure, metabolic syndrome, and CHD potentially mediated by involvement in a proinflammatory status reflected by CRP.

Lipid measures for prediction of incident cardiovascular disease in diabetic and non-diabetic adults: results of the 8.6 years follow-up of a population based cohort study

BACKGROUND

Diabetes is a strong risk factor for cardiovascular disease (CVD).The relative role of various lipid measures in determining CVD risk in diabetic patients is still a subject of debate. We aimed to compare performance of different lipid measures as predictors of CVD using discrimination and fitting characteristics in individuals with and without diabetes mellitus from a Middle East Caucasian population.

METHODS

The study population consisted of 1021 diabetic (men = 413, women = 608) and 5310 non-diabetic (men = 2317, women = 2993) subjects, aged > or = 30 years, free of CVD at baseline. The adjusted hazard ratios (HRs) for CVD were calculated for a 1 standard deviation (SD) change in total cholesterol (TC), log-transformed triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), non-HDL-C, TC/HDL-C and log-transformed TG/HDL-C using Cox proportional regression analysis. Incident CVD was ascertained over a median of 8.6 years of follow-up.

RESULTS

A total of 189 (men = 91, women = 98) and 263(men = 169, women = 94) CVD events occurred, in diabetic and non-diabetic population, respectively. The risk factor adjusted HRs to predict CVD, except for HDL-C, TG and TG/HDL-C, were significant for all lipid measures in diabetic males and were 1.39, 1.45, 1.36 and 1.16 for TC, LDL-C, non- HDL-C and TC/HDL-C respectively. In diabetic women, using multivariate analysis, only TC/HDL-C had significant risk [adjusted HR1.31(1.10-1.57)].Among non-diabetic men, all lipid measures, except for TG, were independent predictors for CVD however; a 1 SD increase in HDL-C significantly decreased the risk of CVD [adjusted HR 0.83(0.70-0.97)].In non-diabetic women, TC, LDL-C, non-HDL-C and TG were independent predictors.There was no difference in the discriminatory power of different lipid measures to predict incident CVD in the risk factor adjusted models, in either sex of diabetic and non-diabetic population.

CONCLUSION

Our data according to important test performance characteristics provided evidence based support for WHO recommendation that along with other CVD risk factors serum TC vs. LDL-C, non-HDL-C and TC/HDL-C is a reasonable lipid measure to predict incident CVD among diabetic men. Importantly, HDL-C did not have a protective effect for incident CVD among diabetic population; given that the HDL-C had a protective effect only among non- diabetic men.

Serum apolipoprotein C-III in high-density lipoprotein: a key diabetogenic risk factor in Turks

AIMS

We studied determinants of serum apolipoprotein C-III (apoC-III) and whether levels of apoC-III or its fractions predict metabolic syndrome (MetS), Type 2 diabetes and coronary heart disease (CHD).

METHODS

The predictive value of apoC-III, measured by immunoturbimetric immunoassay in 802 tracked individuals of a Turkish general population in determining cardiometabolic risk was assessed over 4.4 +/- 1.2 years' follow-up. Patients with MetS, Type 2 diabetes and CHD at baseline were excluded.

RESULTS

Total apoC-III, as well as both fractions, was significantly, linearly and inversely related to smoking status, positively to alcohol usage and to levels of complement C3. Mid and high tertiles of total or non-high density lipoprotein (HDL) apoC-III predicted significantly and independently incident MetS; they predicted CHD with risk ratios of 1.6 [95% confidence intervals (CI) 1.02-2.5], for 1 sd increment, after adjustments that included HDL cholesterol and body mass index (BMI). The highest tertile of HDL apoC-III was a major independent predictor of new-onset diabetes with a 2.5-fold risk ratio for 1 sd increment (95% CI 1.5-4.0) in combined sexes, after adjustment for waist circumference, HDL cholesterol and other confounders and was a better predictor than waist girth.

CONCLUSIONS

Serum total apoC-III or its fractions are linearly and inversely associated with smoking, positively with alcohol usage and serum complement C3. The presumably dysfunctional HDL apoC-III is a stronger predictor of Type 2 diabetes than waist girth in Turks. Non-HDL apoC-III predicts strongly the development of MetS as well as incident CHD, independent of HDL cholesterol, BMI and non-lipid factors. The atherogenicity of apoC-III and dysfunctionality of HDL apoC-III carry huge public health implications in Turks.