The Association of Lipoprotein(a) Plasma Levels With Prevalence of Cardiovascular Disease and Metabolic Control Status in Patients With Type 1 Diabetes

Correlation between circulating lipoprotein(a) levels and cardiovascular events risk in patients with type 2 diabetes

Background

High circulatory lipoprotein(a) [Lp(a)] concentration promotes atherosclerosis; however, its efficacy in predicting the extent of atherosclerotic coronary heart disease (CHD) with coronary artery obstruction and major adverse cardiovascular events (MACEs) in diabetic patients remains questionable. This study aimed to examine whether elevated circulating Lp(a) levels exacerbate CHD and to assess their utility in predicting MACEs in individuals diagnosed with type 2 diabetes mellitus (T2DM).

Methods

In total, 4332 patients diagnosed with T2DM who underwent coronary angiography (CAG) were included and categorized into two groups (CHD and non-CHD) based on the CAG results. We used a correlation analysis to explore the potential links between the levels of circulating Lp(a) and CHD severity. Cox regression analysis was performed to evaluate MACEs.

Results

The concentrations of circulating Lp(a) were markedly elevated in the CHD group and positively correlated with disease severity. Our results indicate that elevated circulating Lp(a) is a crucial risk factor that significantly contributes to both the progression and severity of CHD. The differences between the two groups are evident in the risk of CHD occurrence [odds ratio (OR) = 1.597, 95 % confidence interval (CI): 1.354-1.893, p < 0.001], the different levels of vessel involvement (OR = 1.908 for triple-vessel vs. single-vessel disease, 95 % CI: 1.401-2.711, p < 0.001), and their relation to the Gensini Score (OR = 2.002 for high vs. low GS, 95 % CI: 1.514-2.881, p < 0.001). Over the course of the 7-year follow-up period, the multivariate Cox regression analysis indicated that increased levels Lp(a) levels are independently associated with the occurrence of MACEs [hazard ratio (HR) = 1.915, 95 % CI: 1.571-2.493, p < 0.001].

Conclusion

We confirmed a positive correlation among circulating Lp(a) levels, CHD lesions count, and Gensini scores. Moreover, Lp(a) levels have predictive significance for the occurrence of MACEs in T2DM patients.

Determinants of vascular impairment in type 1 diabetes-impact of sex and connexin 37 gene polymorphism: A cross-sectional study

BACKGROUND

The associations of risk factors with vascular impairment in type 1 diabetes patients seem more complex than that in type 2 diabetes patients. Therefore, we analyzed the associations between traditional and novel cardiovascular risk factors and vascular parameters in individuals with T1D and modifications of these associations according to sex and genetic factors.

METHODS

In a cross-sectional study, we analyzed the association of risk factors in T1D individuals younger than 65 years using vascular parameters, such as ankle brachial index (ABI) and toe brachial index (TBI), duplex ultrasound, measuring the presence of plaques in carotid and femoral arteries (Belcaro score) and intima media thickness of carotid arteries (CIMT). We also used photoplethysmography, which measured the interbranch index expressed as the Oliva-Roztocil index (ORI), and analyzed renal parameters, such as urine albumin/creatinine ratio (uACR) and glomerular filtration rate (GFR). We evaluated these associations using multivariate regression analysis, including interactions with sex and the gene for connexin 37 (Cx37) polymorphism (rs1764391).

RESULTS

In 235 men and 227 women (mean age 43.6 ± 13.6 years; mean duration of diabetes 22.1 ± 11.3 years), pulse pressure was strongly associated with unfavorable values of most of the vascular parameters under study (ABI, TBI, Belcaro scores, uACR and ORI), whereas plasma lipids, represented by remnant cholesterol (cholesterol - LDL-HDL cholesterol), the atherogenic index of plasma (log (triglycerides/HDL cholesterol) and Lp(a), were associated primarily with renal impairment (uACR, GFR and lipoprotein (a)). Plasma non-HDL cholesterol was not associated with any vascular parameter under study. In contrast to pulse pressure, the associations of lipid factors with kidney and vascular parameters were modified by sex and the Cx37 gene.

CONCLUSION

In addition to known information, easily obtainable risk factor, such as pulse pressure, should be considered in individuals with T1D irrespective of sex and genetic background. The associations of plasma lipids with kidney function are complex and associated with sex and genetic factors. The decision of whether pulse pressure, remnant lipoproteins, Lp(a) and other determinants of vascular damage should become treatment targets in T1D should be based on the results of future clinical trials.

Exploring the Interplay between Diabetes and Lp(a): Implications for Cardiovascular Risk

PURPOSE OF REVIEW

The objective of this manuscript is to review and describe the relationship between Lp(a) and diabetes, exploring both their association and synergy as cardiovascular risk factors, while also describing the current evidence regarding the potential connection between low levels of Lp(a) and the presence of diabetes.

RECENT FINDINGS

Epidemiological studies suggest a potential relationship between low to very low levels of Lp(a) and diabetes. Lipoprotein(a), or Lp(a), is an intriguing lipoprotein of genetic origin, yet its biological function remains unknown. Elevated levels of Lp(a) are associated with an increased risk of cardiovascular atherosclerosis, and coexisting diabetes status confers an even higher risk. On the other hand, epidemiological and genetic studies have paradoxically suggested a potential relationship between low to very low levels of Lp(a) and diabetes. While new pharmacological strategies are being developed to reduce Lp(a) levels, the dual aspects of this lipoprotein's behavior need to be elucidated in the near future.

Comparative Analysis of Atherogenic Lipoproteins L5 and Lp(a) in Atherosclerotic Cardiovascular Disease

PURPOSE OF REVIEW

Low-density lipoprotein (LDL) poses a risk for atherosclerotic cardiovascular disease (ASCVD). As LDL comprises various subtypes differing in charge, density, and size, understanding their specific impact on ASCVD is crucial. Two highly atherogenic LDL subtypes-electronegative LDL (L5) and Lp(a)-induce vascular cell apoptosis and atherosclerotic changes independent of plasma cholesterol levels, and their mechanisms warrant further investigation. Here, we have compared the roles of L5 and Lp(a) in the development of ASCVD.

RECENT FINDINGS

Lp(a) tends to accumulate in artery walls, promoting plaque formation and potentially triggering atherosclerosis progression through prothrombotic or antifibrinolytic effects. High Lp(a) levels correlate with calcific aortic stenosis and atherothrombosis risk. L5 can induce endothelial cell apoptosis and increase vascular permeability, inflammation, and atherogenesis, playing a key role in initiating atherosclerosis. Elevated L5 levels in certain high-risk populations may serve as a distinctive predictor of ASCVD. L5 and Lp(a) are both atherogenic lipoproteins contributing to ASCVD through distinct mechanisms. Lp(a) has garnered attention, but equal consideration should be given to L5.

Consensus document on Lipoprotein(a) from the Italian Society for the Study of Atherosclerosis (SISA)

AIMS

In view of the consolidating evidence on the causal role of Lp(a) in cardiovascular disease, the Italian Society for the Study of Atherosclerosis (SISA) has assembled a consensus on Lp(a) genetics and epidemiology, together with recommendations for its measurement and current and emerging therapeutic approaches to reduce its plasma levels. Data on the Italian population are also provided.

DATA SYNTHESIS

Lp(a) is constituted by one apo(a) molecule and a lipoprotein closely resembling to a low-density lipoprotein (LDL). Its similarity with an LDL, together with its ability to carry oxidized phospholipids are considered the two main features making Lp(a) harmful for cardiovascular health. Plasma Lp(a) concentrations vary over about 1000 folds in humans and are genetically determined, thus they are quite stable in any individual. Mendelian Randomization studies have suggested a causal role of Lp(a) in atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis and observational studies indicate a linear direct correlation between cardiovascular disease and Lp(a) plasma levels. Lp(a) measurement is strongly recommended once in a patient's lifetime, particularly in FH subjects, but also as part of the initial lipid screening to assess cardiovascular risk. The apo(a) size polymorphism represents a challenge for Lp(a) measurement in plasma, but new strategies are overcoming these difficulties. A reduction of Lp(a) levels can be currently attained only by plasma apheresis and, moderately, with PCSK9 inhibitor treatment.

CONCLUSIONS

Awaiting the approval of selective Lp(a)-lowering drugs, an intensive management of the other risk factors for individuals with elevated Lp(a) levels is strongly recommended.

Concave likelihood-based regression with finite-support response variables

We propose a unified framework for likelihood-based regression modeling when the response variable has finite support. Our work is motivated by the fact that, in practice, observed data are discrete and bounded. The proposed methods assume a model which includes models previously considered for interval-censored variables with log-concave distributions as special cases. The resulting log-likelihood is concave, which we use to establish asymptotic normality of its maximizer as the number of observations n tends to infinity with the number of parameters d fixed, and rates of convergence of L1 -regularized estimators when the true parameter vector is sparse and d and n both tend to infinity withlog ( d ) / n → 0 $\log (d) / n \rightarrow 0$ . We consider an inexact proximal Newton algorithm for computing estimates and give theoretical guarantees for its convergence. The range of possible applications is wide, including but not limited to survival analysis in discrete time, the modeling of outcomes on scored surveys and questionnaires, and, more generally, interval-censored regression. The applicability and usefulness of the proposed methods are illustrated in simulations and data examples.

Lipoprotein(a) and calcific aortic valve disease initiation and progression: a systematic review and meta-analysis

Although evidence indicates the association of lipoprotein(a) [Lp(a)] with atherosclerosis, the link with calcific aortic valve disease (CAVD) is unclear. This systematic review and meta-analysis explores the connection between Lp(a) and aortic valve calcification and stenosis (AVS). We included all relevant studies, indexed in eight databases, up to February 2023. A total of 44 studies (163 139 subjects) were included, with 16 of them being further meta-analysed. Despite considerable heterogeneity, most studies support the relationship between Lp(a) and CAVD, especially in younger populations, with evidence of early aortic valve micro-calcification in elevated-Lp(a) populations. The quantitative synthesis showed higher Lp(a) levels, by 22.63 nmol/L (95% CI: 9.98-35.27), for patients with AVS, while meta-regressing the data revealed smaller Lp(a) differences for older populations with a higher proportion of females. The meta-analysis of eight studies providing genetic data, revealed that the minor alleles of both rs10455872 and rs3798220 LPA gene loci were associated with higher risk for AVS (pooled odds ratio 1.42; 95% CI: 1.34-1.50 and 1.27; 95% CI: 1.09-1.48, respectively). Importantly, high-Lp(a) individuals displayed not only faster AVS progression, by a mean difference of 0.09 m/s/year (95% CI: 0.09-0.09), but also a higher risk of serious adverse outcomes, including death (pooled hazard ratio 1.39; 95% CI: 1.01-1.90). These summary findings highlight the effect of Lp(a) on CAVD initiation, progression and outcomes, and support the early onset of Lp(a)-related subclinical lesions before clinical evidence.

Association of aortic valve calcification and high levels of lipoprotein (a): Systematic review and Meta-analysis

AIM

This study aimed to assess the association between aortic valve calcification and lipoprotein (a).

METHODS

We searched PUBMED, WOS, and SCOPUS databases. Inclusion criteria were any controlled clinical trials or observational studies that reported the level of Lipoprotein A in patients with aortic valve calcifications, excluding case reports, editorials and animal studies. RevMan software (5.4) was used to perform the meta-analysis.

RESULTS

After complete screening, 7 studies were included with a total number of 446179 patients included in the analysis. The pooled analysis showed a statistically significant association between the incidence of aortic valve calcium and increased levels of lipoprotein (a) compared with controls (SMD = 1.71, 95% CI = 1.04 to 2.38, p-value < 0.00001).

CONCLUSION

This meta-analysis showed a statistically significant association between the incidence of aortic valve calcium and increased levels of lipoprotein (a) compared with controls. Patients with high levels of lipoprotein (a) are at increased risk of developing aortic valve calcification. Medications targeting lipoprotein (a) in future clinical trials may be useful in primary prevention of aortic valve calcification in high risk patients.

Lipid-lowering therapies and cardiovascular risk-stratification strategies in adults with type 1 diabetes

PURPOSE OF REVIEW

Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of mortality in adults with type 1 diabetes (T1D). Although dyslipidaemia is a modifiable and prevalent risk factor in individuals with T1D, determining when to initiate lipid-lowering therapy for primary prevention of ASCVD can be challenging. In this article, recommendations for lipid-lowering therapy from updated clinical guidelines over the last 5 years, additional risk-stratification methods, hypertriglyceridaemia management and potential barriers to optimal care in adults with T1D are discussed.

RECENT FINDINGS

Low-density lipoprotein cholesterol (LDL-C) is the primary target for lipid-lowering. However, international guidelines recommend differing approaches to ASCVD risk-stratification, lipid-lowering, and LDL-C goals in individuals with diabetes, predominantly reflecting evidence from studies in type 2 diabetes. Despite guideline recommendations, several studies have demonstrated that statins are underused, and LDL-C goals are not attained by many individuals with T1D. Additional risk-stratification methods including T1D-specific ASCVD risk calculators, coronary artery calcium scoring, and lipoprotein(a) may provide additional information to define when to initiate lipid-lowering therapy.

SUMMARY

Clinical trial evidence for lipid-lowering therapies in T1D is lacking, and further studies are needed to inform best practice. Optimization and harmonization of ASCVD risk-stratification and lipid management in individuals with T1D is required.

Study on the relationship between lipoprotein (a) and diabetic kidney disease

OBJECTIVE

Little is currently known about the role of lipid metabolism in diabetic kidney disease (DKD), warranting further study. The present study sought to investigate the correlation between lipid metabolism and renal function as well as renal pathological grade/score in DKD patients.

METHODS

A total of 224 patients diagnosed with DKD by pathological examination were retrospectively analyzed, of which 74 patients were further evaluated by DKD pathological grade/score. ANOVA was used to investigate serum lipoprotein (a) [Lp (a)] levels in DKD patients with different chronic kidney disease (CKD) stages. Spearman correlation analysis was used to evaluate the relationship between Lp (a) and renal function-related indicators. The DKD pathological grade/score was also evaluated with this method. The receiver operating characteristic (ROC) curve was used to analyze the value of Lp (a) in assessing renal function and pathological changes.

RESULTS

There were significant differences in Lp (a) levels among different CKD stages (H = 17.063, p = 0.002) and glomerular grades (H = 12.965, p = 0.005). Lp (a) levels correlated with serum creatinine (p = 0.000), blood urea nitrogen (p = 0.000), estimated glomerular filtration rate (p = 0.000), 24-h proteinuria (24hUPro, p = 0.000), urine microalbumin (p = 0.000), urine albumin creatinine ratio (p = 0.000), glomerular basement membrane thickness (p = 0.003), and glomerular grade (p = 0.039). ROC curve demonstrated good performance of Lp (a) as an indicator to assess CKD stage 4-5 (AUC = 0.684, p = 0.000), 24hUPro > 3.5 g (AUC = 0.720, p = 0.000), and glomerular grade III-IV (AUC = 0.695, p = 0.012).

CONCLUSIONS

Elevated levels of Lp (a) are associated with decreased GFR, increased proteinuria, and renal pathological progression, suggesting they could be used to monitor changes in DKD patients.

There is urgent need to treat atherosclerotic cardiovascular disease risk earlier, more intensively, and with greater precision: A review of current practice and recommendations for improved effectiveness

Atherosclerotic cardiovascular disease (ASCVD) is epidemic throughout the world and is etiologic for such acute cardiovascular events as myocardial infarction, ischemic stroke, unstable angina, and death. ASCVD also impacts risk for dementia, chronic kidney disease peripheral arterial disease and mobility, impaired sexual response, and a host of other visceral impairments that adversely impact the quality and rate of progression of aging. The relationship between low-density lipoprotein cholesterol (LDL-C) and risk for ASCVD is one of the most highly established and investigated issues in the entirety of modern medicine. Elevated LDL-C is a necessary condition for atherogenesis induction. Basic scientific investigation, prospective longitudinal cohorts, and randomized clinical trials have all validated this association. Yet despite the enormous number of clinical trials which support the need for reducing the burden of atherogenic lipoprotein in blood, the percentage of high and very high-risk patients who achieve risk stratified LDL-C target reductions is low and has remained low for the last thirty years. Atherosclerosis is a preventable disease. As clinicians, the time has come for us to take primordial and primary prevention more serously. Despite a plethora of therapeutic approaches, the large majority of patients at risk for ASCVD are poorly or inadequately treated, leaving them vulnerable to disease progression, acute cardiovascular events, and poor aging due to loss of function in multiple visceral organs. Herein we discuss the need to greatly intensify efforts to reduce risk, decrease disease burden, and provide more comprehensive and earlier risk assessment to optimally prevent ASCVD and its complications. Evidence is presented to support that treatment should aim for far lower goals in cholesterol management, should take into account many more factors than commonly employed today and should begin significantly earlier in life.

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.

Lipoprotein(a) and Cardiovascular Outcomes in Patients With Coronary Artery Disease and Different Metabolic Phenotypes

Background

The positive relationship between metabolic healthy obesity (MHO) and cardiovascular risk has been under debate in recent years. Previously, strong evidence supported the causal role of increased plasma lipoprotein(a) [Lp(a)] levels in cardiovascular disease (CVD). The current study aimed to investigate the different associations of Lp(a) and cardiovascular events (CVEs) in patients with coronary artery disease (CAD) and different metabolic phenotypes.

Methods

A total of 5,089 patients who were angiography-proven CAD were consecutively included and followed up for CVEs. Obesity was defined as a body mass index (BMI) ≥25 kg/m² according to Asia-specific BMI criteria. Patients were divided into four groups according to metabolic phenotypes, namely metabolically healthy/unhealthy non-obese and metabolically healthy/unhealthy obese [metabolically healthy non-obese (MHN), MHO, metabolically unhealthy non-obese (MUN), and metabolically unhealthy obesity (MUO)]. Comparisons of CAD severity and outcomes were performed among four groups. Cox regression analyses and cubic spline models were used to examine the relationship between Lp(a) and CVEs in patients with different metabolic phenotypes.

Results

During a median of 7.5 years’ follow-up, 540 (10.6%) CVEs occurred. MUN and MUO populations had more severe coronary stenosis than MHN ones, while no significant difference in the Gensini score (GS) was observed between MHN and MHO. Patients with MUN and MUO presented a higher risk of CVEs than patients with MHN (hazard ratio [HR]: 1.414, 95% CI: 1.024–1.953–1.556 and HR: 1.747, 95% CI: 1.295–1.363, p < 0.05). In subgroup analysis, restricted cubic spline models showed that there was no association between Lp(a) and CVEs in patients in MHN and MHO, while the MUN and MUO groups presented increasing associations between Lp(a) and CVEs and such association was stronger in the MUO group. In Cox regression analysis, Lp(a) >50 mg/dl was associated with a 2.032- and 2.206-fold higher risk of subsequent CVEs in the MUO and MUN subgroups, respectively.

Conclusion

Among patients with angiography-proven stable CAD, Lp(a) had a more significant prognostic value in both MUO and MUN individuals regardless of obesity, suggesting the importance of screening for cardiovascular risk with Lp(a) in metabolically unhealthy patients.

Study on the relationship between hormone and Lp(a) in Chinese overweight/obese patients

BACKGROUND

Obesity is a risk factor for metabolic diseases and often influences hormone change. Lipoprotein (a) (Lp(a)) is associated with various metabolic diseases, but there are few studies on the relationship between Lp(a) and hormones in obese patients. This study investigated the the relationship between Lp(a) and hormones in Chinese overweight/obese people.

METHODS

A total of 410 overweight/obese patients (Body mass index (BMI) ≥ 25 kg/m²) were included and underwent sociodemographic data investigations and relevant clinical examinations. Lp(a) was analyzed by colorimetric enzymatic assays and hormone was measured with chemiluminescence immunoassay method. According to Lp(a) levels, they were categorized into 3 groups: the lower Lp(a) group (Lp(a) levels < 30 mg/dl), the moderate Lp(a) group (Lp(a) levels between 30 mg/dl and 120 mg/dl) and the higher Lp(a) group (Lp(a) levels > 120 mg/dl). The differences of hormone levels among the three groups were compared and the relationship between Lp(a) and hormones was analyzed by Spearman's rank correlation.

RESULTS

The higher Lp(a) group had significantly lower testosterone (TES) levels compared with the lower and moderate Lp(a) groups in the case of gender, age and BMI matching. Lp(a) concentration was negatively correlated with TES levels in all participants and the negative association between Lp(a) and TES levels was also observed when the analysis was stratified by gender. Additionally, the TES was statistically related with Lp(a) levels in the multiple linear regression model (95% confidence interval: - 0.451 to - 0.079).

CONCLUSIONS

TES levels was negatively associated with Lp(a) levels in Chinese overweight/obese patients.

Lp(a) and the Risk for Cardiovascular Disease: Focus on the Lp(a) Paradox in Diabetes Mellitus

Lipoprotein(a) (Lp(a)) is one of the strongest causal risk factors of atherosclerotic disease. It is rich in cholesteryl ester and composed of apolipoprotein B and apo(a). Plasma Lp(a) levels are determined by apo(a) transcriptional activity driven by a direct repeat (DR) response element in the apo(a) promoter under the control of (HNF)4α Farnesoid-X receptor (FXR) ligands play a key role in the downregulation of APOA expression. In vitro studies on the catabolism of Lp(a) have revealed that Lp(a) binds to several specific lipoprotein receptors; however, their in vivo role remains elusive. There are more than 1000 publications on the role of diabetes mellitus (DM) in Lp(a) metabolism; however, the data is often inconsistent and confusing. In patients suffering from Type-I diabetes mellitus (T1DM), provided they are metabolically well-controlled, Lp(a) plasma concentrations are directly comparable to healthy individuals. In contrast, there exists a paradox in T2DM patients, as many of these patients have reduced Lp(a) levels; however, they are still at an increased cardiovascular risk. The Lp(a) lowering mechanism observed in T2DM patients is most probably caused by mutations in the mature-onset diabetes of the young (MODY) gene and possibly other polymorphisms in key transcription factors of the apolipoprotein (a) gene (APOA).

Lp(a) and the Risk for Cardiovascular Disease: Focus on the Lp(a) Paradox in Diabetes Mellitus

Lipoprotein(a) (Lp(a)) is one of the strongest causal risk factors of atherosclerotic disease. It is rich in cholesteryl ester and composed of apolipoprotein B and apo(a). Plasma Lp(a) levels are determined by apo(a) transcriptional activity driven by a direct repeat (DR) response element in the apo(a) promoter under the control of (HNF)4α Farnesoid-X receptor (FXR) ligands play a key role in the downregulation of APOA expression. In vitro studies on the catabolism of Lp(a) have revealed that Lp(a) binds to several specific lipoprotein receptors; however, their in vivo role remains elusive. There are more than 1000 publications on the role of diabetes mellitus (DM) in Lp(a) metabolism; however, the data is often inconsistent and confusing. In patients suffering from Type-I diabetes mellitus (T1DM), provided they are metabolically well-controlled, Lp(a) plasma concentrations are directly comparable to healthy individuals. In contrast, there exists a paradox in T2DM patients, as many of these patients have reduced Lp(a) levels; however, they are still at an increased cardiovascular risk. The Lp(a) lowering mechanism observed in T2DM patients is most probably caused by mutations in the mature-onset diabetes of the young (MODY) gene and possibly other polymorphisms in key transcription factors of the apolipoprotein (a) gene (APOA).

Lp(a) and the Risk for Cardiovascular Disease: Focus on the Lp(a) Paradox in Diabetes Mellitus

Lipoprotein(a) (Lp(a)) is one of the strongest causal risk factors of atherosclerotic disease. It is rich in cholesteryl ester and composed of apolipoprotein B and apo(a). Plasma Lp(a) levels are determined by apo(a) transcriptional activity driven by a direct repeat (DR) response element in the apo(a) promoter under the control of (HNF)4α Farnesoid-X receptor (FXR) ligands play a key role in the downregulation of APOA expression. In vitro studies on the catabolism of Lp(a) have revealed that Lp(a) binds to several specific lipoprotein receptors; however, their in vivo role remains elusive. There are more than 1000 publications on the role of diabetes mellitus (DM) in Lp(a) metabolism; however, the data is often inconsistent and confusing. In patients suffering from Type-I diabetes mellitus (T1DM), provided they are metabolically well-controlled, Lp(a) plasma concentrations are directly comparable to healthy individuals. In contrast, there exists a paradox in T2DM patients, as many of these patients have reduced Lp(a) levels; however, they are still at an increased cardiovascular risk. The Lp(a) lowering mechanism observed in T2DM patients is most probably caused by mutations in the mature-onset diabetes of the young (MODY) gene and possibly other polymorphisms in key transcription factors of the apolipoprotein (a) gene (APOA).

Lipoprotein(a): Pathophysiology, measurement, indication and treatment in cardiovascular disease. A consensus statement from the Nouvelle Société Francophone d'Athérosclérose (NSFA)

Lipoprotein(a) is an apolipoprotein B100-containing low-density lipoprotein-like particle that is rich in cholesterol, and is associated with a second major protein, apolipoprotein(a). Apolipoprotein(a) possesses structural similarity to plasminogen but lacks fibrinolytic activity. As a consequence of its composite structure, lipoprotein(a) may: (1) elicit a prothrombotic/antifibrinolytic action favouring clot stability; and (2) enhance atherosclerosis progression via its propensity for retention in the arterial intima, with deposition of its cholesterol load at sites of plaque formation. Equally, lipoprotein(a) may induce inflammation and calcification in the aortic leaflet valve interstitium, leading to calcific aortic valve stenosis. Experimental, epidemiological and genetic evidence support the contention that elevated concentrations of lipoprotein(a) are causally related to atherothrombotic risk and equally to calcific aortic valve stenosis. The plasma concentration of lipoprotein(a) is principally determined by genetic factors, is not influenced by dietary habits, remains essentially constant over the lifetime of a given individual and is the most powerful variable for prediction of lipoprotein(a)-associated cardiovascular risk. However, major interindividual variations (up to 1000-fold) are characteristic of lipoprotein(a) concentrations. In this context, lipoprotein(a) assays, although currently insufficiently standardized, are of considerable interest, not only in stratifying cardiovascular risk, but equally in the clinical follow-up of patients treated with novel lipid-lowering therapies targeted at lipoprotein(a) (e.g. antiapolipoprotein(a) antisense oligonucleotides and small interfering ribonucleic acids) that markedly reduce circulating lipoprotein(a) concentrations. We recommend that lipoprotein(a) be measured once in subjects at high cardiovascular risk with premature coronary heart disease, in familial hypercholesterolaemia, in those with a family history of coronary heart disease and in those with recurrent coronary heart disease despite lipid-lowering treatment. Because of its clinical relevance, the cost of lipoprotein(a) testing should be covered by social security and health authorities.

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.

Plasma lipoprotein(a) measured in the routine clinical care is associated to atherosclerotic cardiovascular disease during a 14-year follow-up

AIMS

To investigate plasma lipoprotein(a) [Lp(a)] levels measured in routine clinical care and their association with mortality and cardiovascular disease.

METHODS AND RESULTS

This retrospective registry-based observational cohort study includes all individuals with plasma Lp(a) results measured at the Karolinska University Laboratory 2003-17. Outcome data were captured in national outcome registries. Levels of Lp(a) expressed in mass or molar units were examined separately. In adjusted Cox regression models, association between deciles of plasma Lp(a) concentrations, mortality, and cardiovascular outcomes were assessed. A total of 23 398 individuals [52% females, mean (standard deviation) age 55.5 (17.2) years, median Lp(a) levels 17 mg/dL or 19.5 nmol/L] were included. Individuals with an Lp(a) level >90th decile (>90 mg/dL or >180 nmol/L) had hazard ratios (95% confidence interval) of 1.25 (1.05-1.50) for major adverse cardiovascular events (P = 0.013), 1.37 (1.14-1.64) for atherosclerotic cardiovascular disease (P = 0.001), and 1.62 (1.28-2.05) for coronary artery disease (P ≤ 0.001), compared to individuals with Lp(a) ≤50th decile. No association between Lp(a) and mortality, peripheral artery disease, or ischaemic stroke was observed.

CONCLUSION

High Lp(a) levels are associated with adverse cardiovascular disease outcomes also in individuals with Lp(a) measured in routine clinical care. This supports the 2019 ESC/EAS recommendation to measure Lp(a) at least once during lifetime to assess cardiovascular risk and implies the need for intensive preventive therapy in patients with elevated Lp(a).

Lipoprotein (a) and diabetes mellitus: causes and consequences

PURPOSE OF REVIEW

This review provides an update on the role of lipoprotein (a) [Lp(a)] in diabetes, including its impact as a risk factor as well as its contribution to the development of cardiovascular disease.

RECENT FINDINGS

Although a specific role for Lp(a) has not yet been conclusively established, it appears to have an inverse association with risk of diabetes. Several population-based studies have demonstrated associations between low levels of Lp(a) and increased risk of type 2 diabetes, but Mendelian randomization studies do not consistently support causality. Conversely, in patients with type 2 diabetes, elevated Lp(a) levels are associated with an increased risk of cardiovascular events.

SUMMARY

Although Lp(a) contributes to the development of cardiovascular disease in patients with diabetes, few trials have investigated the benefits of reducing Lp(a) within this patient population. Furthermore, guidelines do not specifically address the risk associated with elevated Lp(a) levels. Despite this, Lp(a) should be measured in patients with diabetes and considered when evaluating their overall risk burden.

The Safety of Pharmacological and Surgical Treatment of Diabetes in Patients with Diabetic Retinopathy-A Review

BACKGROUND

Diabetes mellitus (DM) is a non-infectious pandemic of the modern world; it is estimated that in 2045 it will affect 10% of the world's population. As the prevalence of diabetes increases, the problem of its complications, including diabetic retinopathy (DR), grows. DR is a highly specific neurovascular complication of diabetes that occurs in more than one third of DM patients and accounts for 80% of complete vision loss cases in the diabetic population. We are currently witnessing many groundbreaking studies on new pharmacological and surgical methods of treating diabetes.

AIM

The aim of the study is to assess the safety of pharmacological and surgical treatment of DM in patients with DR.

MATERIAL AND METHODS

An analysis of the data on diabetes treatment methods currently available in the world literature and their impact on the occurrence and progression of DR.

RESULTS

A rapid decrease in glycaemia leads to an increased occurrence and progression of DR. Its greatest risk accompanies insulin therapy and sulfonylurea therapy. The lowest risk of DR occurs with the use of SGLT2 inhibitors; the use of DPP-4 inhibitors and GLP-1 analogues is also safe. Patients undergoing pancreatic islet transplants or bariatric surgeries require intensive monitoring of the state of the eye, both in the perioperative and postoperative period.

CONCLUSIONS

It is of utmost importance to individualize therapy in diabetic patients, in order to gradually achieve treatment goals with the use of safe methods and minimize the risk of development and progression of DR.

Emerging insights into the relationship between hyperlipidemia and the risk of diabetic retinopathy

Hyperlipidemia is correlated with a series of health problems. Notably, aside from its established role in promoting cardiovascular morbidity and mortality, hyperlipidemia has also been considered for modulating the risk and the severity of multiple metabolic disorders. According to the results of epidemiologic investigations, several certain circulating lipoprotein species are correlated with the prevalence of diabetic retinopathy, suggesting that the physiological and pathological role of these lipoproteins is analogous to that observed in cardiovascular diseases. Furthermore, the lipid-lowering treatments, particularly using statin and fibrate, have been demonstrated to ameliorate diabetic retinopathy. Thereby, current focus is shifting towards implementing the protective strategies of diabetic retinopathy and elucidating the potential underlying mechanisms. However, it is worth noting that the relationship between major serum cholesterol species and the development of diabetic retinopathy, published by other studies, was inconsistent and overall modest, revealing the relationship is still not clarified. In this review, the current understanding of hyperlipidemia in pathogenesis of diabetic retinopathy was summarized and the novel insights into the potential mechanisms whereby hyperlipidemia modulates diabetic retinopathy were put forward.