Elevated lipoprotein(a) levels predict cardiovascular disease in type 2 diabetes mellitus: a 10-year prospective cohort study

Lipoprotein (a) Levels and Abdominal Aortic Aneurysm. A Systematic Review and Meta-analysis

BACKGROUND

Several studies have linked high Lipoprotein (a) (Lp(a)) concentrations to cardiovascular events, including the formation of Abdominal Aortic Aneurysms (AAA). We review and meta-analyze existing evidence on the association of Lp(a) levels with AAA.

METHODS

Studies evaluating the link of Lp(a) with AAA, up to December 27th 2021, were identified by a systematic search of PubMed, SCOPUS, and Web of Science databases. The results were qualitatively and quantitatively synthesized according to PRISMA guidelines. Results are presented as standardized mean differences (SMD) with 95% confidence intervals (CI).

RESULTS

A total of 5,078 subjects (1,637 patients with AAA vs. 3,441 controls) from 11 studies were included in the meta-analysis, with a mean age of 69.9 years and a male sex prevalence of 85.8%. Based on the qualitative synthesis, high Lp(a) concentrations are linked to abdominal aortic wall degradation and extracellular matrix disarrangement. Moreover, despite the considerable variability among races, high Lp(a) levels are related to increased AAA risk, independently of race differences. Accordingly, patients with AAA displayed significantly higher Lp(a) levels compared to controls (SMD: 0.86, 95% CI: 0.55-1.17, p < 0.001). The outcome was not affected in a sensitivity analysis excluding three outlying studies (SMD: 0.40, 95% CI: 0.22-0.58, p < 0.001).

CONCLUSION

This meta-analysis indicates the association between high Lp(a) levels and the presence of AAA, although existing literature presents high heterogeneity. Further studies are needed to standardize Lp(a) measurements and to conclude whether Lp(a) can be used as a sensitive biomarker of early presymptomatic AAA diagnosis.

Association of C-peptide and lipoprotein(a) as two predictors with cardiometabolic biomarkers in patients with type 2 diabetes in KERCADR population-based study

We sought association between serum Lipoprotein(a) and C-Peptide levels as two predictors with cardiometabolic biomarkers in patients with type 2 diabetes mellitus. This nested case-control study was conducted on 253 participants with type 2 diabetes mellitus and control from the second phase of the KERCADR cohort study. The participants were randomly allocated into case and control groups. The quantitative levels of Lipoprotein(a) and C-Peptide were measured by ELISA. Atherogenic indices of plasma were measured. The plasma Atherogenic Index of Plasma significantly decreased (P = 0.002) in case-male participants, and plasma Castelli Risk Index II level significantly increased (P = 0.008) in control-male participants with the highest dichotomy of Lipoprotein(a). The plasma Atherogenic Index of Plasma level in case-female participants significantly increased (P = 0.023) with the highest dichotomy of C-Peptide. Serum C-Peptide level significantly increased (P = 0.010 and P = 0.002, respectively) in control-male participants with the highest dichotomies of Atherogenic Index of Plasma and Castelli Risk Index I. There was a significant association between the highest quartile of C-Peptide and higher anthropometric values in case participants; and higher atherogenic indices of plasma and anthropometric values in control participants. Raised serum C-peptide than raised Lipoprotein(a) can be a prior predictor for cardiometabolic disease risk in healthy participants and patients with type 2 diabetes mellitus with increased cardiometabolic biomarkers. Case and control males with general and visceral obesity and case and control females with visceral obesity are exposure to increased C-peptide, respectively. Lipoprotein(a) may be risk independent biomarker for type 2 diabetes mellitus. Reducing raised Lipoprotein(a) levels to less than 30ng/ml with strict control of low density lipoprotein cholesterol would be the best approach to prevent coronary artery disease consequences. It is suggested that a screening system be set up to measure the Lp(a) levels in the community for seemingly healthy people or individuals with one or more cardiometabolic biomarkers.

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.

Lipoprotein(a) Concentrations Correlate With LDL-C in Children With Type 1 and 2 Diabetes

Context

Elevated levels of lipoprotein(a) (Lp[a]) is an independent risk factor for atherosclerotic cardiovascular disease especially in patients with diabetes. Adult levels of Lp(a) are thought to be is expressed by the second year of life.

Objective

We hypothesized that Lp(a) would be influenced by low density lipoprotein cholesterol (LDL-C), race, and HbA1C.

Methods

Retrospective electronic medical record review of children and adolescents with type 1 diabetes (T1D) (n = 607) and type 2 diabetes (T2D) (n = 93).

Results

Total of 700 subjects, ages 12-19 years with T1D (n = 607) and T2D (n = 93), 49% were male, mean age was 13.2 ± 3.08 years, and the median Lp(a) was 8.00 mg/dL, IQR 5.00-12.00. The Black subjects had an increased relative risk (RR) of higher Lp(a) compared with White subjects (RR 1.25, P < .0001). Among patients with T1D, Black people had an increased relative risk of higher Lp(a) than White people (RR 1.23, P = .0002). In T2D, Black subjects have 43% higher risk of having elevated Lp(a) than White subjects (RR 1.43, P = .268). In T1D, a 5 mg/dL increase in LDL-C results in 2% increase in Lp(a) (P < .0001). In T2D, a 5 mg/dL increase of LDL-C results in an increase of Lp(a) by 3%. LDL-C and BMI are independently associated with Lp(a) (RR = 1.02, P < .001; RR = 0.98, P < .001).

Conclusion

Our data suggest that Lp(a) is associated with LDL-C in children with diabetes. Lp(a) is differentially increased at higher concentrations of LDL-C. Black children with diabetes have a significant burden of Lp(a) concentrations compared with White children.

Mild Malnutrition Contributes the Greatest to the Poor Prognosis in Coronary Artery Disease With Well-Controlled Low-Density Lipoprotein Cholesterol Levels: A 4,863 Chinese Cohort Study

Background: Previous studies reported that patients with coronary artery disease (CAD) and well-controlled baseline LDL-C (<1.8 mmol/L) still had higher long-term all-cause mortality. However, no study has been conducted to explore the independent risk factors for long-term mortality. In addition, there also was no study evaluating the population attributable risk (PAR) of independent risk factors in combination with their prevalence and relative risk. Therefore, we aimed to identify the independent risk factors and estimate their PAR in patients with CAD and well-controlled baseline LDL-C (<1.8 mmol/L). Methods: We analyzed 4,863 consecutive CAD patients with well-controlled baseline LDL-C admitted to Guangdong Provincial People's Hospital in China from January 2007 to December 2018. Independent risk factors for long-term all-cause death were evaluated through stepwise approach and multivariable Cox regression analysis. PAR of independent risk factors was calculated with their hazard ratio and prevalence among our cohort. Results: The overall mortality was 16.00% (n = 778) over a median follow-up period of 5.93 years. Independent risk factors for all-cause death included malnutrition, age ≥75 years, congestive heart failure (CHF), chronic kidney disease (CKD) and atrial fibrillation. Among these risk factors of interest, the hazard ratio (HR) of severe malnutrition was the highest (HR 2.82, 95% CI: 1.86-4.26), and the PAR of mild malnutrition was the highest (19.49%, 95% CI: 0.65-36.01%). Conclusion: Malnutrition, age ≥75 years, CHF, CKD and atrial fibrillation were independent predictors for long-term all-cause mortality in CAD patients with well-controlled LDL-C levels. Considering prevalence of these risk factors, more attention should be paid to the occurrence of mild malnutrition for these patients. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT04407936.

High lipoprotein(a) concentrations are associated with lower type 2 diabetes risk in the Chinese Han population: a large retrospective cohort study

Background

Lipoprotein (a) [Lp(a)] is a proven independent risk factor for coronary heart disease. It is also associated with type 2 diabetes mellitus (T2DM). However, the correlation between Lp(a) and T2DM has not been clearly elucidated.

Methods

This was a retrospective cohort study involving 9248 T2DM patients and 18,496 control individuals (1:2 matched). Patients were randomly selected from among inpatients in the Second Affiliated Hospital of Nanchang University between 2006 and 2017. Clinical characteristics were compared between the two groups. Spearman rank-order correlation coefficients were used to evaluate the strength and direction of monotonic associations of serum Lp(a) with other metabolic risk factors. Binary logistic regression analysis was used to establish the correlation between Lp(a) levels and T2DM risk.

Results

The median Lp(a) concentration was lower in T2DM patients than in controls (16.42 vs. 16.88 mg/dL). Based on four quartiles of Lp(a) levels, there was a decrease in T2DM risk from 33.7% (Q1) to 31.96% (Q4) (P for trend < 0.0001). Then, Lp(a) levels > 28.72 mg/dL (Q4) were associated with a significantly lower T2DM risk in the unadjusted model [0.924 (0.861, 0.992), P = 0.030]. Similar results were obtained in adjusted models 1 [Q4, 0.925 (0.862, 0.993), P = 0.031] and 2 [Q4, 0.919 (0.854, 0.990), P = 0.026]. Furthermore, in the stratified analysis, Q4 of Lp(a) was associated with a significantly lower T2DM risk among men [0.813 (0.734, 0.900), P < 0.001] and those age > 60 years [0.819 (0.737, 0.910), P < 0.001]. In contrast, the low-density lipoprotein cholesterol (LDL-C) levels and coronary heart disease (CHD) did not impact these correlations between Lp(a) and diabetes.

Conclusions

There is an inverse association between Lp(a) levels and T2DM risk in the Chinese population. Male patients, especially those aged more than 60 years with Lp(a) > 28.72 mg/dL, are low-risk T2DM individuals, regardless of LDL-C levels and CHD status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01504-x.

Association Between Lipoprotein(a) and Risk Factors of Atherosclerosis in Russian Population (Data of Observational ESSE-RF study)

Experimental and clinical data indicate a significant contribution of lipoprotein(a) (Lp[a]) to the atherogenesis. However, the pathophysiological mechanisms of this relationship are not fully understood.

Aim. To investigate the distribution of Lp(a) in the population of the regions participating in the Study “Epidemiology of Cardiovascular Diseases in the Regions of the Russian Federation” (ESSE-RF) and to evaluate its associations with cardiovascular risk factors.

Material and methods. Representative samples of the male and female population of 7 regions of the Russian Federation, aged from 25 to 64 years, enrolled in the multi-center cross-sectional epidemiological study were analyzed. A total of 10332 people were examined, of whom 3732 were men (36.0%) and 6600 were women (64.0%), the average age was equal in both sexes.

Results. The mean value of Lp(a) reached 22.4 mg/dl (standard deviation 21.3 mg/dl) and significantly differed from the median (11.1 mg/dl; interquartile range from 3.9 to 20.2 mg/dl), forming the right-skewed distribution in both male and female population. Lp(a) levels were statistically significantly correlated with the level of low-density lipoproteins cholesterol (LDL-C), ароВ/аpoAI and total cholesterol. Notably, the odds ratios were growing by quintiles, and increased along with increasing lipid values (p<0.0001). Lp(a) levels were also positively associated with high-sensitivity C-reactive protein (hs-CRP) and negatively correlated with blood concentration of glucose and triglycerides (TG). There were no associations with body mass index, waist circumference and smoking status.

Conclusion. According to the ESSE-RF data, there are significant positive associations of Lp(a) with the LDL-C level, the ароВ/аpoAI ratio, total cholesterol, and hs-CRP. Negative associations are established with glucose and TG levels. The future studies should be planned with the notion of the Lp(a)’s right-skewed distribution type. 

Effect of Niacin on Carotid Atherosclerosis in Patients at Low-Density Lipoprotein-Cholesterol Goal but High Lipoprotein (a) Level: a 2-Year Follow-Up Study

Objective

To examine the effect of niacin on the progression of carotid intima-media thickness (IMT) in patients with high level of lipoprotein (Lp) (a).

Methods

Patients at low-density lipoprotein-cholesterol goal but with Lp (a) >25 mg/dL and mean carotid IMT >0.75 mm were included. Eligible patients were randomized at a 1:2 ratio into one of two groups for 24 months: control or 1,500 mg extended release niacin. The primary study outcomes were the percentage changes in mean and maximal carotid IMT. The percentage change in lipid profiles including Lp (a) was analyzed as a secondary study outcome.

Results

Among 96 randomized patients, 31 completed the study (mean age: 65 years; male: 44%). At follow-up, the percentage change in mean carotid IMT was not significantly different between the two groups (−1.4%±15.5% and −1.1%±7.3% in the control and niacin groups, respectively, p=0.95). The percentage change in maximal carotid IMT was also similar in the two groups (0.7%±16.5% and −4.4%±11.6%, respectively, p=0.35). Elevation of high-density lipoprotein-cholesterol tended to be higher in the niacin group (p=0.07), and there was a significant difference in the percentage change in hemoglobin A1c between the two groups (−1.9%±2.2% and 3.3%±6.7%, respectively, p=0.02). Reduction of Lp (a) was greater in the niacin-treated group compared to placebo, but the difference was not statistically significant.

Conclusion

Treatment with niacin for two years did not inhibit the progression of carotid intima-media thickening in patients with high Lp (a) level. However, this study may have been underpowered to evaluate the primary study outcome.

Elevated lipoprotein (a) levels are associated with the presence and severity of coronary artery disease in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

The role of lipoprotein (a) [Lp(a)] in coronary artery diseases (CAD) with special clinical background such as type 2 diabetes mellitus (T2DM) has not been fully determined. The aim of the present study was to investigate the relation of Lp(a) to type 2 diabetic patients with or without CAD.

METHODS AND RESULTS

A total of 2040 consecutive patients with T2DM who received selective coronary angiography (CAG) due to angina-like chest pain were enrolled. The patients were subsequently divided into CAD and non-CAD groups according to the results of CAG. The severity of CAD was evaluated by the Gensini Score (GS), number of stenotic vessels, and history of myocardial infarction (MI). Data showed that Lp(a) levels were higher in the CAD group than in the non-CAD group (median: 15.00 mg/dL vs. 11.88 mg/dL, P = 0.025). The results from CAD subgroup analysis indicated that the patients with MI, multiple-vessel disease and high GS had higher Lp(a) levels compared with those in their matched subgroups (P < 0.05, respectively). After adjustment for confounders, Lp(a) levels were independently related to the presence and severity of CAD (CAD:OR = 1.564; MI:OR = 1.523; high GS:OR = 1.388; multiple-vessel disease:OR = 1.455; P < 0.05, respectively).

CONCLUSION

Elevated Lp(a) levels were independently associated with the presence and severity of CAD in patients with T2DM. More studies are necessary to confirm our findings.

Is a Previously or Currently Reduced Testosterone Level in Male Patients with Type 2 Diabetes Mellitus a Risk Factor for the Development of Coronary Artery Disease? A Systematic Review and Meta-analysis

INTRODUCTION

We aimed to systematically investigate the association between testosterone level and cardiovascular risk in male patients with type 2 diabetes mellitus (T2DM) by comparing male T2DM patients with low testosterone levels to male T2DM patients with normal testosterone levels at baseline in terms of the number of cases of coronary artery disease (CAD).

METHODS

Online databases were carefully searched for studies relating to testosterone, diabetes mellitus, and cardiovascular risk by using the search terms 'testosterone,' 'diabetes mellitus,' and 'coronary artery/cardiovascular disease.' The only endpoint in this analysis was CAD/atherosclerosis/coronary plaque/major adverse coronary event prior to or following testosterone reduction at baseline. The analytical parameters used in this analysis were the risk ratio (RR) with the 95% confidence interval (CI), as obtained using the RevMan 5.3 software.

RESULTS

3467 male patients with T2DM (1079 patients with a low testosterone level versus 2388 patients with a normal testosterone level) were included. The results of this analysis showed that when a random effects model was used, a higher risk of CAD/cardiovascular disease was observed in diabetic patients with a low testosterone level than in those with a normal testosterone level (RR 1.24, 95% CI 0.94-1.63; P = 0.13). However, the difference in risk was not statistically significant. Similarly, with a fixed effects model, a low testosterone level was associated with a higher CAD/cardiovascular risk of disease (RR 1.12, 95% CI 0.98-1.34; P = 0.08); in this case, the difference in risk between the T2DM patients with low and normal testosterone levels approached statistical significance.

CONCLUSION

A previously or currently reduced testosterone level was not found to be statistically significantly associated with a high risk of CAD/cardiovascular disease in male patients with T2DM. However, the difference in risk between the T2DM patients with low and normal testosterone levels was observed to approach statistical significance.

ApoB/ApoA-I ratio is independently associated with carotid atherosclerosis in type 2 diabetes mellitus with well-controlled LDL cholesterol levels

BACKGROUND/AIMS

This study aimed to investigate whether the apolipoprotein (Apo) B/ApoA-I ratio is associated with carotid intima-media thickness (CIMT) in type 2 diabetes mellitus (T2DM) subjects with low density lipoprotein cholesterol (LDL-C) levels less than 100 mg/dL.

METHODS

This cross-sectional study included 845 subjects aged with T2DM 40 to 75 years who had visited Huh's Diabetes Center in Seoul, Republic of Korea for CIMT measurement. Traditional fasting lipid profiles, ApoB and ApoA-I levels were examined. CIMT was measured at three points on the far wall of 1 cm long section of the common carotid artery in the proximity of the carotid bulb. The mean value of six measurements from right and left carotid arteries were used as the mean CIMT. In this study, carotid atherosclerosis was defined as having a focal plaque or diffuse thickening of the carotid wall (mean CIMT ≥ 1.0 mm).

RESULTS

The prevalence of carotid atherosclerosis increased with ApoB/ApoA-I ratio. The ApoB/ApoA-I ratio, expressed as both quartiles (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.21 to 3.79; p for trend = 0.014) and continuous values (OR, 10.05; 95% CI, 3.26 to 30.97; p < 0.001), was significantly associated with a higher risk for carotid atherosclerosis, regardless of conventional cardiovascular disease risk factors. The optimal ApoB/ApoA-I ratio cutoff value for detecting carotid atherosclerosis was 0.57, based on receiver operating characteristic curve analysis with a sensitivity of 58.0% and a specificity of 55.1%.

CONCLUSIONS

A high ApoB/ApoA-I ratio was significantly associated with carotid atherosclerosis in T2DM patients with LDL-C levels less than 100 mg/dL.

The mixed benefit of low lipoprotein(a) in type 2 diabetes

Background

Lipoprotein(a) (Lp(a)), a variant low-density lipoprotein (LDL), is a major genetic risk factor for cardiovascular disease. It is unknown whether an inverse relationship exists between Lp(a) and β-cell function (BCF), as for LDL-cholesterol (LDL-C) lowering by statins.

We therefore assessedthe cardiometabolic phenotype of 340 men with type 2 diabetes mellitus (T2DM) in relation to Lp(a), focusing on BCF and hyperbolic product [BxS], which adjusts BCF to insulin sensitivity and secretion.

Methods

Two groups were analyzed according to Lp(a) quartiles (Q): a (very-)low Lp(a) (Q1;n = 85) vs a normal-to-high Lp(a) group (Q2-Q4;n = 255).

Results

In the overall cohort, mean Lp(a) was 52 nmol.L⁻¹. Median Lp(a) was 6 nmol.L⁻¹ (Q1) vs 38 nmol.L⁻¹ (Q2-Q4). There were no differences between groups regarding age; education; diabetes duration; body mass index; body composition and smoking. Q1 had significantly worse glycemic control, higher systolic blood pressure, more severe metabolic syndrome, and more frequent hepatic steatosis. Insulin sensitivity was significantly lower (− 37%) in Q1, who also had lesser hyperbolic product (− 27%), and higher [BxS] loss rate (+ 15%). Q1 also had higher frequency (+31%) and severity (+20%) of atherogenic dyslipidemia. Microangiopathy and neuropathy were higher in Q1 (+ 34% and + 48%, respectively), whereas Q2-Q4 patients had increased macroangiopathy (+ 51%) and coronary artery disease (CAD; + 94%).

Conclusions

Low Lp(a) appears both beneficial and unhealthy in T2DM. It is associated with unfavourable cardiometabolic phenotype, lesser BCF, poorer glycemic control, and increased microvascular damage despite being linked to markedly reduced CAD, suggesting that Lp(a)-related vascular risk) follows a J-shaped curve.