Lipids and lipoprotein(a) concentrations in Tunisian type 2 diabetic patients; Relationship to glycemic control and coronary heart disease

Relevance of oxidative stress biomarkers, hemoglobin A1c, troponin-I, and angiotensin-converting enzyme metabolism to blood pressure in acute myocardial infarction: a case-control study

The aim was to investigate this relationship by calculating 1) the correlation between peak troponin-C (peak-cTnI), levels of oxidative stress biomarkers, including lipid peroxidation products (malondialdehyde (MDA), conjugated dienes (CD)), and antioxidant enzyme activity (glutathione peroxidase (GPx)), and HbA1c and 2) the correlation between HbA1c and serum angiotensin-converting enzyme (ACE) activity, and its impact on the rate pressure product (RPP) in acute myocardial infarction (AMI). A case-control study was performed in 306 AMI patients having undergone coronary angiography and on 410 controls. GPx activity was reduced in association with increased MDA and CD in patients. Peak-cTnI was positively correlated with HbA1c, MDA, and CD levels. Serum ACE activity was negatively correlated with GPx. HbA1c was positively correlated with ACE activity and RPP. Linear regression analysis showed that peak-cTnI, ACE activity and HbA1c are significant predictors of AMI. Elevated HbA1c and peak-cTnI levels are associated with RPP elevation causing AMI. In conclusions, patients with elevated HbA1c, elevated ACE activity and cTnI are at increased risk of AMI with increasing RPP. Patients at risk of AMI can be identified at an early stage if the biomarkers HbA1c, ACE activity, and cTnI are measured and preventive measures are taken in a targeted manner.

Clinical investigation of lipoprotein (a) levels in type 2 diabetics for cariovascular diseases prediction and prognosis

OBJECTIVES

We aimed to evaluate the levels of serum lipoprotein a, LP (a), in Jordanian patients with type 2 diabetes mellitus (DM); and to examine its relation to glycemic control, metabolic syndrome (MS) and duration of DM. The LP (a) is considered one of the independent risk factors for coronary artery disease (CAD) in the general population.

METHODS

Fasting blood samples were drawn from 51 diabetic patients with type 2 DM and 31 non-diabetic age and sex control subjects. Serum LP (a) was measured along with other parameters, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c) and glycosylated haemoglobin (HbA_1c). Correlation analyses were performed between LP (a) and the various variables measured.

RESULTS

LP (a) measurement showed a skewed distribution towards the lower levels in both groups. Mean LP (a) levels showed a statistically insignificant difference between the two groups. No correlations of LP (a) were observed with age, sex or body mass index (BMI). No correlations of LP (a) with LDL-c, HDL-c, TG, TC, MS, DM duration or HbA_1c were observed. The LP (a) serum levels were significantly higher in type 2 diabetic patients with retinopathy.

CONCLUSIONS

LP (a) serum levels are not increased in type 2 diabetic patients; so, LP (a) may not be a reliable marker for early therapeutic interventions in DM patients, even in high-risk for thrombosis groups.

Association Between Genetic Variants in FADS1-FADS2 and ELOVL2 and Obesity, Lipid Traits, and Fatty Acids in Tunisian Population

The aim of this study was to determine whether genetic variants in FADS1/FADS2 and ELOVL2 are associated with overweight–obesity and body mass index (BMI) and to assess the association between these genetic variants and lipid profile and fatty acid levels. A total of 259 overweight–obese patients were compared to 369 healthy controls. FADS1, FADS2, and ELOVL2 genes were associated with BMI and overweight–obesity (P ≤ .001). In an additive model, the C allele in each of these variants was associated with a lower BMI: −1.18, −0.90, and −1.23 units, respectively. Higher amounts of total cholesterol, low-density lipoprotein cholesterol, total saturated fatty acids (lauric [12:0], myristic [C14:0], palmitic [C16:0], stearic [C18:0], arachidic [20:0], lignoceric [24:0]), monounsaturated fatty acids (myristoleic [C14:1], erucic [C22:1 n-9]), and polyunsaturated fatty acids (α-linolenic [ALA, 18:3 n-3], docosahexaenoic [DHA, C22:6 n-3], eicosapentaenoic acid [EPA, C20:5n-3], arachidonic acid [AA, 20:4n-6], and conjugated linolenic acids [CLA1 and CLA2]) were shown in patients. A significant increase in D6D activities presented by 20:4n-6/18:2n-6 and 18:3n-6/18:2n-6, Δ9 desaturase (D9D) activity, estimated by the ratio 18:1n-9/18:0 and elongase activities (AE), and estimated by the ratio of docosatetraenoic/AA and DPA/EPA in patients. The C minor allele of FADS1 had significantly lower DHA. A significant decrease in stearic acid, EPA, and AE activity (docosatetraenoic/AA) was revealed in patients with the minor allele carriers of FADS2. The C minor allele of ELOVL2 had significantly lower ALA, EPA, DPA, and D6D activity (C20:4 n-6/C18:2n-6). These data suggest that variations in FADS1, FADS2, and ELOVL2 affect the risk of overweight–obesity and the level of circulating fatty acids and could point to a key molecular pathway of metabolic syndrome and its related comorbidities.

Investigating the Atherogenic Risk of Lipoprotein(a) in Type 2 Diabetic Patients

Type 2 diabetes mellitus (T2DM) has high morbidity and results in increased risk of mortality mainly due to cardiovascular diseases. Different factors have been found to be responsible for the increased prevalence of coronary artery disease (CAD) in T2DM. One of these factors includes raised serum levels of lipoprotein(a) (Lp(a)). The present study was designed to evaluate the association of Lp(a) levels with T2DM in Libyan patients and find the degree of association between Lp(a), glycemic control, insulin, and lipid profile. The study included 100 T2DM patients, recruited from the Benghazi Center for Diagnosis and Treatment of Diabetes, and 30 apparently healthy age and sex-matched individuals, to serve as controls. All participants completed a questionnaire to obtain clinical information and medical history. Blood samples were collected and analyzed for Lp(a), fasting blood glucose (FBS), HbA1c, insulin, total cholesterol (TC), triglycerides (TAG), low-density lipoprotein c (LDL-c), and high-density lipoprotein c (HDL-c). The results from the comparison between the control and experimental groups showed that Lp(a) was significantly higher in diabetic patients. It showed the positive correlation with TC and LDL-c. On the contrary, it showed no significant correlations with glycemic control parameters nor insulin, TAG, HDL-c, body mass index (BMI), and blood pressor (BP). Cardiovascular disease (CVD) risk in type 2 diabetic patients could be dependent on risk factors other than LDL-c, which may not be an independent risk factor for the development and progression of atherogenesis in T2DM. Lp(a) may be a new metabolic syndrome risk factor, and it may be useful as a cardiovascular risk biomarker in future clinical practice.

Correlation of trans fatty acids with the severity of coronary artery disease lesions

BACKGROUND

Nutritional choices, which include the source of dietary fatty acids (FA), have an important significant impact on coronary artery disease (CAD). We aimed to determine on patients with CAD the relationships between Trans fatty acids (Trans FA) and different CAD associated parameters such as inflammatory and oxidative stress parameters in addition to Gensini score as a vascular severity index.

METHODS

Fatty acid profiles were established by gas chromatography from 111 CAD patients compared to 120 age-matched control group. Lipid peroxidation biomarkers, oxidative stress, inflammatory parameters and Gensini score were studied.

RESULTS

Our study showed a significant decrease of the antioxidant parameters levels such as erythrocyte glutathione peroxydase (GPx) and superoxide dismutase (SOD) activities, plasma antioxidant status (FRAP) and thiol (SH) groups in CAD patients. On the other hand, catalase activity, conjugated dienes and malondialdehyde were increased. Plasmatic and erythrocyte Trans FA were also increased in CAD patients compared to controls. Furthermore, divergent associations of these Trans FA accumulations were observed with low-density lipoprotein-cholesterol/ high-density lipoprotein-cholesterol (LDL-C/HDL-C) ratio, Apolipoprotein B (ApoB), lipid peroxidation parameters, high-sensitivity C Reactive Protein (hs-CRP), Interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and Gensini score. Especially, elaidic acid (C18:1 trans 9), trans C18:2 isomers and trans 11 eicosanoic acid are correlated with these parameters. Trans FA are also associated with oxidative stress, confirmed by a positive correlation between C20:1 trans 11 and GPx in erythrocytes.

CONCLUSIONS

High level of Trans FA was highly associated with the induction of inflammation, oxidative stress and lipoperoxidation which appear to be based on the vascular severity and might be of interest to assess the stage and progression of atherosclerosis. The measurement of these Trans FA would be of great value for the screening of lipid metabolism disorders in CAD patients.

Association of plasma fatty acid alteration with the severity of coronary artery disease lesions in Tunisian patients

Background

Some factors related to diet are known to be involved in the progression of atherosclerosis in humans.

Methods

The relationship between plasma fatty acid (FA) levels and the severity of coronary artery disease (CAD), evaluated by Gensini score (GS), was investigated in CAD Tunisian patients compared to controls. Lipid profiles were analyzed, GS was calculated in CAD and non-CAD patients and compared to controls.

Results

CAD patients showed an alteration of conventional lipid parameters. In fact, a significant increase of plasmatic triglycerides (TG) level, atherogenic lipid ratios (TC/HDL-C,TG/HDL-C, LDL-C/HDL-C); and ApoB/ApoA1 was observed in the CAD group comparatively to controls (p < 0.001).

Gensini score was showed to be a good indicator to evaluate cholesterol metabolism disorders associated with HDL-C since a negative association was found between HDL-C levels and GS for the two groups of patients. In addition, in the relation with FA and classes of FA, a negative association was found as expected, between Gensini score and total MUFA, PUFA n-3, total PUFA, GLA, DGLA and DHA. Furthermore, a positive association with stearic and erucic acid was found. Suggests that, GS is also a good indicator to evaluate FA metabolic disorders. Higher elongation index and modifications of desaturation index (D5D, D6D and D9D) were observed in patients compared to controls, supporting FA metabolism modifications.

Conclusions

In conclusion, although that Tunisian population appears to follow the Mediterranean diet, variations of plasmatic FA levels and desaturase activities in CAD patients highlights an alteration of FA metabolism and suggests an important implication of certain FA in the development of atherosclerosis.

Plasma proprotein convertase subtilisin/kexin type 9 is associated with Lp(a) in type 2 diabetic patients

AIM

Recent in vitro researches have shown that plasma Lp(a) can be reduced using a proprotein convertase subtilisin/kexin type 9 (PCSK9)-inhibitory monoclonal antibody. In our clinical study we tried to investigate the association between plasma Lp(a) and PCSK9 in Type 2 diabetic patients with elevated plasma Lp(a), and to check whether such an association would be related to LDL-receptor (LDL-R) levels.

METHODS

Plasma PCSK9 and LDL-R concentrations were measured by sandwich ELISA methods using recombinant human PCSK9 protein and LDL-R protein as standards in a cohort with type 2 diabetic patients (n=50) compared to an age- and sex-matched control group (n=50). Both clinical and biochemical parameters were determined in all patients.

RESULTS

Plasma PCSK9 level was significantly elevated in T2DM patients compared to controls (44.61±14.44 and 33.22±11.79ng/mL, respectively, P<0.0001). However LDL-R levels did not differ between the two groups. Remarkably, plasma PCSK9 levels were positively correlated with Lp(a) levels in whole population (r=+0.227, P=0.03) as well as in T2DM group (r=+0.398, P=0.0061) but not in control group. Multiple linear regression analysis showed that plasma Lp(a) levels were independently associated to those of PCSK9.

CONCLUSION

Lp(a) has been proposed as a contributing factor to the accelerated development of macrovascular complications in T2DM. Its synergic effect with PCSK9 may explain the enhanced atherogenicity in T2DM patients.

Elevated serum β2-glycoprotein-I-lipoprotein(a) complexes levels are associated with the presence and complications in type 2 diabetes mellitus

AIMS

To examine the serum levels of β2-glycoprotein I-lipoprotein(a) complexes [β2-GPI-Lp(a)] in type 2 diabetes mellitus (T2DM) patients and evaluate the association of the complexes with complications in T2DM.

METHODS

Fifty two T2DM patients (22 with complications and 30 free of complications) and 52 age/gender-matched healthy controls were studied. Serum concentrations of β2-GPI-Lp(a) and ox-Lp(a) were measured by "sandwich" ELISAs and their associations with complications were examined using multiple linear regression.

RESULTS

Mean serum β2-GPI-Lp(a) (1.19 ± 0.30 U/mL vs. 0.89 ± 0.20 U/mL, p<0.001) and ox-Lp(a) concentrations (13.34 ± 11.73 mg/L vs. 5.26 ± 3.34 mg/L, p<0.001) were both significantly higher in T2DM than in controls. The area under the ROC curve (AUC) for β2-GPI-Lp(a) and ox-Lp(a) was 0.725 and 0.738, respectively. β2-GPI-Lp(a) levels were markedly higher in patients with complications than those without complication (1.39 ± 0.28 U/mL vs. 1.04 ± 0.31 U/mL, p<0.01), whereas no marked difference was found in ox-Lp(a). In multivariate regression analysis, the association between β2-GPI-Lp(a) and complications remained significant (β=0.249, p<0.05, respectively) after adjustments were made for other traits.

CONCLUSIONS

Elevated β2-GPI-Lp(a) may reflect chronic underlying pathophysiological processes involved in development of complications of T2DM.

Renin-angiotensin system polymorphisms in relation to hypertension status and obesity in a Tunisian population

Essential hypertension (HTA) is the clinical expression of a disordered interaction between the genetic, physiological, and biochemical systems that under usual conditions maintain cardiovascular homeostasis. We studied the effects of the angiotensinogen M235T, angiotensin converting enzyme insertion/deletion (ACE I/D), and angiotensin II receptor 1 (AT1R) A1166C gene polymorphisms on the risk of HTA and to evaluate the relationship between these polymorphisms and obesity. We performed AGT, ACE and AGTR genotyping in 142 hypertensive patients and 191 control subjects using PCR-RFLP methods and PCR, respectively. The three polymorphisms were significantly associated with HTA. Individuals carrying the mutated TT of AGT, DD of ACE and CC of AT1R genotypes had an 1.67 (P = 0.032), 3.09 (P < 0.001) and 3.45 (P < 0.001)-fold increased risk of HTA. After adjustment for sex, smoking, diabetes, dyslipidemia, BMI, triglycerides and DD, TT and CC genotypes, BMI was independent risk factor of HTA (OR = 3.14; P < 0.001). An association of BMI with ACE gene polymorphism (P = 0.035), whereas no association with AGT and AT1R gene polymorphisms was obtained. The proportion of hypertensives is as high as 21.8 and 13.4% in the overweight and the obese DD group. The present study implies that the genotyping for the variants of RAS gene could in the future become an important part of the clinical process of risk identification for HTA.

The CC genotype of the angiotensin II type I receptor gene independently associates with acute myocardial infarction in a Tunisian population

Acute myocardial infarction (AMI) is a multifactorial disease influenced by environmental and genetic factors. The aim of this study was to assess the association of angiotensin II type 1 receptor (ATR1) gene polymorphisms with AMI as well as to evaluate the role of serum angiotensin-converting enzyme (ACE) activity and that of cardiac troponin I (cTnI) in Tunisian AMI patients. One hundred and eighteen AMI patients were compared to 150 healthy controls. ATR1 genotypes were determined by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The ATR1 A1166C polymorphism was significantly associated with AMI ( p = 0.024). CC genotype and C allele frequencies were associated with increased AMI risk [CC vs. AC and AA: OR = 2.06; p = 0.045; 95 % CI (1.02–4.18); C vs. A: OR = 1.68; p = 0.004; 95 % CI (1.17–2.41)]. By multivariate logistic regression analysis, CC genotype, hypertension, diabetes, serum ACE activity and peak-cTnI were significant independent predictors of AMI. Increased serum ACE activity and cTnI peak levels were associated with the CC genotype in AMI patients. In conclusion, the ATR1 A1166C polymorphism is associated with AMI and the CC genotype associated with increased ACE activity and cTnI levels appear to predispose for AMI risk.

Angiotensinogen gene polymorphism in acute myocardial infarction patients

Introduction. The objective of the study was to explore the role of a genetic variant of angiotensinogen (AGT), M235T, as an independent risk factor for acute myocardial infarction (AMI) and to investigate the possible association with the severity of coronary artery disease (CAD), estimated on the basis of the number of coronary stenoses and critical arterial occlusions.

Patients and methods. 123 AMI patients were compared to 144 healthy controls. AGT genotypes were determined by PCR.

Results. A significant association was found between AGT M235T polymorphism and AMI ( p = .021). By logistic regression, the TT genotype appeared to confer 1.9-fold increased risk for AMI in both the univariate and the multivariate model. The frequencies of the TT genotype and T allele increased with the number of stenoses in coronary vessels. Moreover, the TT genotype and the T allele were more frequent in the subgroup of patients with stenoses in at least four coronary vessels than in other patients, including subjects with one- to three-vessel disease. Furthermore, the TT genotype and the T allele were significantly more frequent in patients with critical arterial occlusions (> 90%) than in subjects without critical stenoses.

Conclusions. The AGT M235T polymorphism associates with AMI risk and influences CAD severity.

Association of the C677T MTHFR Polymorphism With Homocysteine, Ox-LDL Levels, and Thiolactonase Activities in the Severity of Coronary Syndrome

Coronary artery diseases (CAD) are influenced by multiple genes of modest effect as the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism, related to MTHFR activity and total plasma homocysteine (tHcy) concentration. This study was designed to evaluate tHcy, oxidized low-density lipoprotein (LDL) (ox-LDL), high-sensibility C-reactive protein (Hs CRP) levels, and homocysteine thiolactonase (HTase) activities as new risk factors for CAD and to investigate an association between MTHFR polymorphism tHcy concentrations and coronary syndrome severity. Our results showed significantly higher levels of tHcy and ox-LDL in patients associated with lower HTase activities. These levels increased proportionally to disease severity. Total plasma Hcy levels were negatively correlated to HTase activities in patients where the TT genotype was significantly more frequent. In a multivariate analysis, tHcy level was the only independent factor affecting the coronary syndrome severity. High tHcy levels are associated with coronary syndrome severity and may be explained either by the elevated prevalence of TT genotype or by the diminished HTase activities.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in a Tunisian healthy and acute myocardial infarction population

INTRODUCTION

The role of the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene (ACE) on acute myocardial infarction (AMI) is controversial.

OBJECTIVES

To assess the effect of the ACE I/D polymorphism on AMI compared with the healthy controls and its relationship with serum ACE activity in a Tunisian population.

DESIGN AND METHODS

A total of 119 patients with AMI were compared with 238 healthy controls from the same geographical area. ACE genotyping was determined by polymerase chain reaction, and serum ACE activity was measured with N-[3-(2-furylacryloyl]-L-phenylalanyl-L-glycyl-L-glycine as substrate.

RESULTS

The ACE I/D polymorphism was significantly different between patients and controls (p < 0.0001). The frequencies of the DD genotype and the D allele were statistically higher in patients with AMI as compared with the controls and were associated with increased risk of AMI (DD vs. ID and II: odds ratio = 4.27, p < 0.0001, 95% confidence interval = 2.65-6.86; D vs. I: odds ratio = 3.15, p < 0.0001, 95% confidence interval = 2.26-4.40). This association was independent of other cardiovascular risk factors but dyslipidemia (p = 0.002) that was not represented in AMI patients with II genotype and in a lower extent with hypertension (p < 0.05). Serum ACE activity was significantly higher in AMI patients with ACE DD genotype compared with the subjects with ID or II genotype (p = 0.034) and was not correlated with other cardiovascular risk factors.

CONCLUSIONS

ACE DD genotype associated with higher serum ACE activity is increased in the studied population and might be clinically useful as markers to assess risk for AMI.

Genotypic interactions of renin-angiotensin system genes with diabetes type 2 in a Tunisian population

AIMS

To explore the role of genetic variants of angiotensinogen (AGT M235T), angiotensin-converting enzyme (ACE I/D), and angiotensin type 1 receptor (AT1R A1166C) as predictors of diabetes risk and to examine their combined effects on type 2 diabetes mellitus (T2DM) patients.

MAIN METHODS

One hundred and fourteen T2DM patients were compared to 175 healthy controls with similar age and sex.

KEY FINDINGS

The genotypic frequencies for all three genes alone were significantly associated with increased risk of developing diabetes. Logistic regression analysis of classic coronary risk factors and the genetic polymorphisms demonstrated that hypertension and ACE DD genotype were the most significant contributors to T2DM. For the renin-angiotensin system (RAS) genes, the risk of T2DM in individuals with one risk genotype was 1.9 (95%CI: 1.1-3.0, p=0.017) higher than those with zero risk genotype. Individuals who carried two risk genotypes had a 4.0 (95%CI 1.7-9.4, p=0.001) times higher risk of T2DM than those who did not carry any risk genotypes of the RAS genes. Most interestingly, the risk of T2DM for individuals with three risk genotypes was 26.2 (95%CI: 5.8-117.9, p<0.001) higher than those with zero risk genotype.

SIGNIFICANCE

The results of the present study imply that genotyping of renin-angiotensin system genes could become an important part of the clinical process of risk identification for T2DM in Tunisian population.

Relationship between genetic polymorphisms of angiotensin-converting enzyme and methylenetetrahydrofolate reductase as risk factors for type 2 diabetes in Tunisian patients

BACKGROUND/AIMS

The role of methylenetetrahydrofolate reductase (MTHFR) and angiotensin-converting enzyme (ACE) gene polymorphisms as being risk factors for diabetes is still controversial. The aim was to investigate the distribution of ACE and MTHFR genotypes as well as to evaluate the role of plasmatic total homocysteine levels (tHcy) and ACE activity in Tunisian patients with type 2 diabetes mellitus (T2DM).

DESIGN AND METHODS

115 T2DM patients compared to 116 healthy volunteers.

RESULTS

The ACE I/D polymorphism was significantly associated with diabetes (p<0.0001). The DD genotype and D allele were more frequent in patients compared to control group [DD: OR=4.93; p<0.0001; 95 % CI: 2.71-8.97; D: OR=3.08, 95% CI: 2.09-4.51 p<0.0001]. MTHFR allele and genotype frequencies did not differ between patients and controls. The susceptibility to diabetes in individuals with genotypes DD+vTT was 13.39 and in the individuals with DD+CT was 6.57 times that of the controls. However, individuals with genotypes ID+CC or II+CT have a protective effect against diabetes. The DD and TT genotypes were associated with significantly higher ACE activity and tHcy levels in diabetics.

CONCLUSION

Our data suggest that ACE ID polymorphism may act synergistically with MTHFR C677T polymorphism to assess diabetes risk.

Association of homocysteine thiolactonase activity and PON1 polymorphisms with the severity of acute coronary syndrome

INTRODUCTION

Excess of total homocysteine (tHcy) and decrease of thiolactonase activities (HTase) have been proposed as risk factors for coronary artery diseases (CAD).

OBJECTIVES

We evaluated the relationship of tHcy and HTase with paraoxonase 1 (PON1) gene polymorphism according to CAD severity.

DESIGN AND METHODS

118 healthy volunteers and 91 CAD patients were compared.

RESULTS

Serum levels of tHcy and oxidized LDL (ox-LDL) increased significantly by 26% and 48% in CAD patients and were associated with significantly lower levels of HDL cholesterol (p=0.02) and 42% of decrease in HTase activities (p<0.05). In these patients the HTase activity was negatively associated with tHcy and Hs CRP levels (r=-0.622, p=0.00 and r=-0.355, p=0.007 respectively) but positively associated with apoB and triglyceride levels (r=0.35, p=0.042 and r=0.308, p=0.003 respectively). HTase activity decreased inversely to the number of affected vessels and according to PON1 polymorphism. PON1 Q192R RR and PON1 L55M MM genotypes were associated with higher HTase activities. Only PON1 L55M (MM) genotype frequency was significantly higher in CAD patients than in controls (P<0.05), while its frequency was similar between the two subgroups according to CAD severity. In a multivariate analysis, tHcy levels were the only independent factor affecting the severity of cardiovascular disease (p=0.029).

CONCLUSIONS

High tHcy levels are associated with the severity of cardiovascular disease and may be partly explained by the diminished HTase activities in these patients.

Association between apolipoprotein E polymorphism, lipids, and coronary artery disease in Tunisian type 2 diabetes

BACKGROUND

The relationship between apolipoprotein E (ApoE) polymorphism, fasting lipid parameters, and coronary artery disease (CAD) is controversial.

METHODS

We studied this relationship, for the first time, in Tunisian type 2 diabetic patients. The studied population comprised 157 type 2 diabetic patients (145 of them were not on any lipid-lowering drugs). Fasting lipids were measured by enzymatic methods and ApoE genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Our results showed that the alleles E2, E3, and E4 were found in 4%, 88%, and 8% of patients, respectively. In the total type 2 diabetic population, no association was found between ApoE polymorphism, lipid parameters, and CAD. However, the E4 allele was associated with elevated low-density lipoprotein cholesterol concentration and with CAD in type 2 diabetic men.

CONCLUSION

The effect of ApoE polymorphism on CAD is gender-dependent in the Tunisian type 2 diabetic population. ApoE 4 allele may enhance atherogenesis indirectly by a strong effect on low-density lipoprotein cholesterol.

Hyperhomocysteinemia and elevated ox-LDL in Tunisian type 2 diabetic patients: Role of genetic and dietary factors

INTRODUCTION

Total plasma homocysteine (tHcy) is an emerging risk factor for the development of atherosclerosis. However, its relationship with diabetes is still unclear.

OBJECTIVES

We evaluated the association between tHcy levels and methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype in a type 2 diabetes mellitus (DM) population and their relationship with oxidized LDL (ox-LDL) according to dietary habits and vascular complications.

DESIGN AND METHODS

Eighty-six DM patients were compared to 120 healthy volunteers.

RESULTS

Associated higher tHcy levels and significantly higher ox-LDL levels (p<0.001) were found in DM patients compared to healthy subjects. Homozygosity for the T allele of MTHFR was more frequent in diabetics than in healthy subjects (12.8% vs. 7.2%) and it was associated with higher tHcy levels. Moreover, this elevated level was associated with significantly higher ox-LDL levels in DM patients with hypertension (p<0.05). Improving folate and vitamin C intakes could have beneficial effects on lowering the tHcy and ox-LDL levels.

CONCLUSIONS

The interplay of genetic and dietary factors modulates the effect of homocysteine on cardiovascular risk factors.

Lipoprotein profile in Arabian type 2 diabetic patients. Relationship to coronary artery diseases

AIM

The aim of this study was to assess lipoprotein profile in Qatari patients with type 2 diabetes mellitus (T2DM) and to assess its relationship to coronary artery disease (CAD).

SUBJECTS AND METHODS

This is a prospective study conducted during a period May to October 2004 at the Hamad General Hospital, Doha, State of Qatar. Sample included Qatari nationals (180 with diabetes and 180 without) aged 25 to 65 years.

RESULTS

The present study revealed that consanguinity, obesity, total cholesterol, reduced HDL-cholesterol and triglyceride were more prevalent in diabetic patients. Also, there was statistically significant difference in biochemistry levels between diabetic patients with CAD and without CAD for age, gender, serum creatinine, triglycerides and BMI. The patients' LDL correlated significantly with total Cholesterol and Lp B. Total cholesterol correlated significantly with triglycerides, Lp B and Lp (A).

CONCLUSION

The present study showed that Lp(a) may not be an independent risk factor for CAD in patients with DM.

Association between dietary fat and antioxidant status of Tunisian type 2 diabetic patients

BACKGROUND

The antioxidant enzymes: superoxide dismutase (Cu/Zn SOD) and glutathione peroxidase (GSH-Px) provide a defense against the damage of cells by reactive oxygen species, which increased in diabetic state. It was demonstrated that dietary treatment could improve the antioxidant status in patients with type 2 diabetes mellitus. This study was undertaken to determine if erythrocyte Cu/Zn SOD and GSH-Px activities correlate with dietary nutrients in 35 selected type 2 diabetic patients (21 women and 14 men) without diabetic complications.

RESULTS

We found that erythrocyte Cu/Zn SOD was diminished in patients with poor controlled diabetes and GSH-Px activity was significantly decreased in obese compared with non-obese type 2 diabetic patients (1.07+/-0.87 and 2.36+/-1.99 U/ml, respectively; P=0.024). Both erythrocyte Cu/Zn SOD and GSH-Px activities were positively correlated to erythrocyte omega3-polyunsaturated fatty acids (PUFA). In non-obese diabetic patients, only GSH-Px activity was correlated negatively to the fraction of linoleic acid (18:2omega6) and arachidonic acid (20:4omega6) in erythrocytes phospholipids.

CONCLUSIONS

The data of this study reveal that activities of erythrocyte antioxidant enzymes were altered in type 2 diabetic patients. Further studies are needed to determine if diet supplemented with omega3-PUFA is required to improve antioxidant defense system in diabetic state.

Association of plasma cholesteryl ester transfer protein activity and polymorphism with coronary artery disease extent in Tunisian type II diabetic patients

INTRODUCTION

Cholesteryl ester transfer protein (CETP), a key protein in reverse cholesterol transport, has a controversial role in atherosclerosis.

OBJECTIVES

: We investigated CETP activity and polymorphism in Tunisian type II diabetes and its relationship with coronary artery disease (CAD).

DESIGN AND METHODS

173 type II diabetic patients with or without CAD were compared to 67 controls.

RESULTS

The HDL cholesterol concentration was low in a Tunisian population. The B1 allele of the CETP gene was associated with a low concentration of HDL cholesterol and was more frequent in Tunisians than in other populations. In type II diabetic patients, the B1 allele was associated with increased prevalence of CAD only in men (OR=0.357, CI=0.161-0.791, P=0.01). The CETP activity increased in type II diabetic patients compared to controls (P=0.05). Furthermore, the CETP activity was increased in patients with double or triple vessel disease compared to those with single vessel disease (P=0.025).

CONCLUSIONS

Our data are in favour of an association between CETP and developing CAD, as well as the extent of CAD.

Association of SNP3 polymorphism in the apolipoprotein A-V gene with plasma triglyceride level in Tunisian type 2 diabetes

BACKGROUND

Apolipoprotein A-V (Apo A-V) gene has recently been identified as a new apolipoprotein involved in triglyceride metabolism. A single nucleotide polymorphism (SNP3) located in the gene promoter (-1131) was associated with triglyceride variation in healthy subjects. In type 2 diabetes the triglyceride level increased compared to healthy subjects. Hypertriglyceridemia is a risk factor for coronary artery disease. We aimed to examine the interaction between SNP3 and lipid profile and coronary artery disease (CAD) in Tunisian type 2 diabetic patients.

RESULTS

The genotype frequencies of T/T, T/C and C/C were 0.74, 0.23 and 0.03 respectively in non diabetic subjects, 0.71, 0.25 and 0.04 respectively in type 2 diabetic patients. Triglyceride level was higher in heterozygous genotype (-1131 T/C) of apo A-V (p = 0.024). Heterozygous genotype is more frequent in high triglyceride group (40.9%) than in low triglyceride group (18.8%); p = 0.011. Despite the relation between CAD and hypertriglyceridemia the SNP 3 was not associated with CAD.

CONCLUSION

In type 2 diabetic patients SNP3 is associated with triglyceride level, however there was no association between SNP3 and coronary artery disease.