Serum lipoprotein(a) concentration as a cardiovascular risk factor in Kuwaiti type 2 diabetic patients

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.

Diabetes and associated cardiovascular risk factors in the State of Kuwait: the first national survey

BACKGROUND

Cardiovascular diseases (CVD) are the leading cause of mortality worldwide as well as in Kuwait. People with diabetes have two to five times greater risk of developing CVD as compared with non-diabetic individuals. To date, little information exists on the prevalence and characteristics of cardiovascular risk factors in Kuwait. The objective of this survey was to address the growing burden of diabetes and related cardiovascular risk factors, and to estimate, for the first time, the prevalence of cardiovascular risk factors in the State of Kuwait.

METHODS

The study was carried out using the World Health Organization (WHO) STEPwise approach for surveillance of non-communicable disease risk factors. This study represents a national survey for Kuwaiti nationals aged between 20 and 65 years. All participants were involved in an interview for gathering sociodemographic information, underwent focused physical examination and donated a blood sample for the study-specific laboratory investigations.

RESULTS

A total of 1970 subjects, with a mean age of 48.9 ± 10.5, were screened. The prevalence of cardiovascular risk factors was as follows: diabetes 17.9%, dyslipidaemia 70.3%, hypertension 25.3% and obesity 48.2%. Over 62% had a sedentary lifestyle, and 17.8% were smokers. The prevalence of diabetes and dyslipidaemia increased with age and body mass index. Diabetes was also significantly associated with age above 40 years (OR = 10.5), family history of diabetes (OR = 2.79), hypertension (OR = 2.22), obesity (OR = 2.87) and lower literacy (OR = 4.23).

CONCLUSIONS

This study found that advancing age (≥ 40 years), diabetes mellitus, obesity, positive family history of diabetes, hypertension and dyslipidaemia are significant risk factors for developing CVD in Kuwait as in other parts of the world. Understanding these factors allows for preventive measures to be taken for Kuwaiti population.

Lipoprotein(a): an independent risk factor for ischemic heart disease that is dependent on triglycerides in subjects with type 2 diabetes mellitus

Lipoprotein(a) is an independent risk factor for Ischaemic Heart Disease (IHD) in the general population. There are conflicting reports in the extent of its association with IHD among subjects with Type 2 diabetes mellitus (T2DM).

The aim was to determine the concentration of Lp(a) and its relationship with other lipids parameters among Omani T2DM subjects with and without IHD. An over-night fasting blood sample from 221 T2DM subjects (86 females and 135 males) and 156 non-diabetics (69 females and 87 males) aged 30–70 years (as control) was taken for lipid profile studies.

Lp(a) was significantly lower (p = 0.012) among T2DM subjects 0.123(1.12) g/L compared to non-diabetics 0.246 (1.18)g/L, irrespective of gender.

A significant correlation (Spearman correlation, P = 0.047) was revealed between Lp(a) and IHD among Omani T2DM subjects. The proportions of T2DM subjects with IHD and an Lp(a) >0.3 g/L was higher compared to T2DM without IHD irrespective of gender, for women 42% vs. 27% and for men 17.5 vs. 8%, respectively.

A significant negative correlation existed between Lp(a) and triglycerides (r = 0.41, P = 0.002) among T2DM subjects. In contrast, a significant positive correlation existed between Lp(a) and LDL-chol among the non-diabetic subjects.

Women had significantly higher Lp(a) concentration compared to men ( 0.30 Vs. 0.16 g/L, P < 0.0001) irrespective of the diabetic status.

Lp(a) is an independent risk factor for IHD among Omani T2DM subjects. Lp(a) concentration was significantly lower and negatively correlated with triglycerides among Omani diabetic compared to non-diabetic subjects.

Associations of apolipoprotein E polymorphism with low-density lipoprotein size and subfraction profiles in Arab patients with coronary heart disease

The APOE gene locus has 3 major alleles, E3, E4 and E2, which variably influence coronary heart disease (CHD) risk. Plasma low-density lipoprotein (LDL) profile, another major CHD risk factor, is characterized on the basis of size and density into 2 main patterns: large buoyant LDL and small dense LDL. The latter has also been linked with increased CHD risk. This study investigates associations of specific APOE allelic patterns with LDL size and subfraction profiles in patients with CHD and healthy control subjects. We recruited 2 groups of male subjects: (A) 65 apparently healthy control subjects, median age, 39.0 years (range, 25.0-60.0 years); (B) 50 patients with CHD, median age, 54.0 years (range, 40.0-76.0 years). APOE genotypes were determined by validated polymerase chain reaction-restriction fragment length polymorphism methods, and LDL size and subfractions were assessed by a high-resolution, nongradient polyacrylamide gel electrophoresis technique (LIPOPRINT, Quantimetrix, Redondo Beach, CA). Lipid and other biochemical analyses were done by autoanalyzer techniques. The associations of specific APOE alleles and genotypes with LDL size and subfraction patterns were then assessed. As expected, patients with CHD had a worse atherogenic lipoprotein profile (waist-hip ratio, LDL, uric acid, and apolipoprotein B) than the controls. APOE genotype and allele frequencies were similar for both groups. In either group, median percent large buoyant LDL (pattern A) was greater in controls (51.0% vs 46.5%, P<.001) and percent small dense LDL (pattern B) was greater with CHD (9.0% vs 3.0%, P<.001). The latter also had smaller median particle size (26.5 vs 26.9 nm, P<.001). In controls, percent LDL pattern B was significantly lower with APOE2 than with APO non-E2 (4.0% vs 0.0%, P<.05); in patients with CHD, E2 patients had smaller particle size, and pattern B was significantly lower with non-E2 than with E2 (15.0 vs 8.0, P<.05). With respect to E4, control non-E4 had a smaller median percent LDL pattern B than E4; otherwise, there were no significant findings in relation to APOE type and LDL size and subfractions in both subject groups. These results confirm observations in other populations of increased levels of small dense LDL in patients with CHD. Although the APOE allelic pattern, especially APOE2, could be related to LDL subfraction profiles in control subjects, such associations could not be demonstrated in those with CHD.

Lipoprotein(a), type 2 diabetes and vascular risk in coronary patients

BACKGROUND

Lipoprotein(a) [Lp(a)] is an important cardiovascular risk factor in the general population. However, prospective data on the vascular risk conferred by Lp(a) in patients with diabetes mellitus are scarce and controversial. It is not known whether the diabetic state affects the association of Lp(a) with vascular events among coronary patients.

DESIGN

We measured Lp(a) in 587 consecutive patients undergoing coronary angiography for the evaluation of coronary artery disease. The incidence of vascular events was recorded over 4 years.

RESULTS

At baseline, Lp(a) was significantly lower in patients with type 2 diabetes (T2DM) (n = 136) than in nondiabetic individuals (11 (0.8-30) mg dL(-1) vs. 16 (0.8-51) mg dL(-1); P = 0.025). Prospectively, Lp(a) was a strong and independent predictor of vascular events in nondiabetic patients (standardized adjusted hazard ratio (HR) = 1.461 (1.121-1.904); P = 0.005), but not in patients with T2DM [HR = 0.812 (0.539-1.223); P = 0.320]. An interaction term diabetes x Lp(a) was significant (P = 0.008), indicating that Lp(a) was a significantly stronger predictor of vascular events in nondiabetic patients than in patients with T2DM.

CONCLUSIONS

Lp(a) in diabetic coronary patients is low and not associated with the incidence of vascular events. Although measurement of Lp(a) provides useful information in nondiabetic coronary patients, it is of little value in coronary patients with T2DM.

The role of lipids in the development of diabetic microvascular complications: implications for therapy

Dyslipidemia is a major factor responsible for coronary heart disease and its reduction decreases coronary risk in patients with diabetes mellitus. However, the association of dyslipidemia with microvascular complications and the effect of intervention with lipid-lowering therapy in diabetes have been less investigated. We present the systematic review of association and intervention studies pertaining to dyslipidemia and microvascular disease in diabetes and also review possible mechanisms. Dyslipidemia may cause or exacerbate diabetic retinopathy and nephropathy by alterations in the coagulation-fibrinolytic system, changes in membrane permeability, damage to endothelial cells and increased atherosclerosis. Hyperlipidemia is associated with faster decline in glomerular filtration rate and progression of albuminuria and nephropathy. Recent evidence also suggests a role of lipoprotein(a) in progression of retinopathy and nephropathy in patients with diabetes mellitus. Lipid-lowering therapy, using single agents or a combination of drugs may significantly benefit diabetic retinopathy and diabetic nephropathy. In particular, hydroxymethyl glutaryl coenzyme A reductase inhibitors may be effective in preventing or retarding the progression of microvascular complications because of their powerful lipid-lowering effects and other additional mechanisms. However, most of the data are based on short-term studies, and need to be ascertained in long-term studies. Until more specific guidelines are available, aggressive management of diabetic dyslipidemia, according to currently accepted guidelines, should be continued for the prevention of macrovascular disease which would also benefit microvascular complications.

Plasma lipoprotein(a) levels: a comparison between diabetic and non-diabetic patients with acute ischemic stroke

OBJECTIVE: The aim of this study was to evaluate lipoprotein(a) (Lp(a)), total cholesterol, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), very low density lipoprotein cholesterol (VLDL ), triglycerides , apolipoprotein A (apo A) and B100 (apo B100), uric acid, glycaemic and insulin plasmatic concentrations in patients affected by acute stroke. In this group of patients, we have compared the variables between type 2 diabetic patients and non-diabetic patients. METHOD: We evaluate a total of 34 non-diabetic patients (22 males and 12 females; mean age 66.71 ± 10.83 years) and a group of 26 type 2 diabetic patients (15 males and 11 females; mean age 66.35 ± 9.92 years) in a cross-sectional study. RESULTS: Mean Lp(a) concentration did not significantly differ between type 2 diabetic patients and non-diabetic subjects (29.49 ± 23.09 vs 44.81 ± 44.34 mg/dl). The distribution of Lp(a)levels was highly skewed towards the higher levels in both groups, being over 30 mg/dl in 50%. Lp(a) concentration was positively correlated with abdominal adiposity, using waist-hip ratio(WHR)(p< 0.05). No association was found between Lp(a) and others risk factors like sex, age, other lipidic parameters and the presence of stroke. CONCLUSIONS: Our results showed that there were no significant differences between diabetic and non-diabetic patients' serum Lp(a) levels, which indicates that elevated Lp(a) levels were associated with ischemic stroke, irrespective of the presence of type 2 diabetes mellitus (type 2 DM).