Lipoprotein(a)-activated immunity, insulin resistance and new-onset diabetes

Achieving quantitative reproducibility in label-free multisite DIA experiments through multirun alignment

DIA is a mainstream method for quantitative proteomics, but consistent quantification across multiple LC-MS/MS instruments remains a bottleneck in parallelizing data acquisition. One reason for this inconsistency and missing quantification is the retention time shift which current software does not adequately address for runs from multiple sites. We present multirun chromatogram alignment strategies to map peaks across columns, including the traditional reference-based Star method, and two novel approaches: MST and Progressive alignment. These reference-free strategies produce a quantitatively accurate data-matrix, even from heterogeneous multi-column studies. Progressive alignment also generates merged chromatograms from all runs which has not been previously achieved for LC-MS/MS data. First, we demonstrate the effectiveness of multirun alignment strategies on a gold-standard annotated dataset, resulting in a threefold reduction in quantitation error-rate compared to non-aligned DIA results. Subsequently, on a multi-species dataset that DIAlignR effectively controls the quantitative error rate, improves precision in protein measurements, and exhibits conservative peak alignment. We next show that the MST alignment reduces cross-site CV by 50% for highly abundant proteins when applied to a dataset from 11 different LC-MS/MS setups. Finally, the reanalysis of 949 plasma runs with multirun alignment revealed a more than 50% increase in insulin resistance (IR) and respiratory viral infection (RVI) proteins, identifying 11 and 13 proteins respectively, compared to prior analysis without it. The three strategies are implemented in our DIAlignR workflow (>2.3) and can be combined with linear, non-linear, or hybrid pairwise alignment.

Lipoprotein(a), metabolic profile and new-onset type 2 diabetes in patients with familial combined hyperlipidemia: A 9 year follow-up study

BACKGROUND

Lipoprotein(a) [Lp(a)] appears to have an inverse association with the risk of type 2 diabetes mellitus in the general population.

OBJECTIVE

This study aimed to investigate the prognostic role of Lp(a) regarding the development of type 2 diabetes in the special population of subjects with familial combined hyperlipidemia (FCH).

METHODS

This cohort study included 474 patients (mean age 49.7±11.3 years, 64% males) with FCH, without diabetes at baseline who were followed for a mean period of 8.2±6.8 years. At baseline evaluation venous blood samples were obtained for the determination of lipid profile and Lp(a) levels. The endpoint of interest was the development of diabetes.

RESULTS

Patients with increased Lp(a) levels ≥30 mg/dl compared to those with low Lp(a) levels <30 mg/dl had lower levels of triglycerides (238±113 vs 268±129 mg/dl, p = 0.01), greater levels of high-density lipoprotein (HDL) cholesterol (44±10 vs 41±10 mg/dl, p = 0.01) and hypertension in a greater percentage (42% vs 32%, p = 0.03). The incidence of new-onset diabetes during the follow-up period was 10.1% (n = 48). Multiple Cox regression analysis revealed that increased Lp(a) is an independent predictor of lower diabetes incidence (HR 0.39, 95% CI 0.17-0.90, p = 0.02) after adjustment for confounders.

CONCLUSION

Among subjects with FCH those with higher Lp(a) levels have lower risk for the development of type 2 diabetes. Moreover, the presence of increased Lp(a) seems to differentiate the expression of metabolic syndrome characteristics in patients with FCH, as increased Lp(a) is related to lower levels of triglycerides, greater prevalence of hypertension and higher levels of HDL cholesterol.

Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement

This 2022 European Atherosclerosis Society lipoprotein(a) [Lp(a)] consensus statement updates evidence for the role of Lp(a) in atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis, provides clinical guidance for testing and treating elevated Lp(a) levels, and considers its inclusion in global risk estimation. Epidemiologic and genetic studies involving hundreds of thousands of individuals strongly support a causal and continuous association between Lp(a) concentration and cardiovascular outcomes in different ethnicities; elevated Lp(a) is a risk factor even at very low levels of low-density lipoprotein cholesterol. High Lp(a) is associated with both microcalcification and macrocalcification of the aortic valve. Current findings do not support Lp(a) as a risk factor for venous thrombotic events and impaired fibrinolysis. Very low Lp(a) levels may associate with increased risk of diabetes mellitus meriting further study. Lp(a) has pro-inflammatory and pro-atherosclerotic properties, which may partly relate to the oxidized phospholipids carried by Lp(a). This panel recommends testing Lp(a) concentration at least once in adults; cascade testing has potential value in familial hypercholesterolaemia, or with family or personal history of (very) high Lp(a) or premature ASCVD. Without specific Lp(a)-lowering therapies, early intensive risk factor management is recommended, targeted according to global cardiovascular risk and Lp(a) level. Lipoprotein apheresis is an option for very high Lp(a) with progressive cardiovascular disease despite optimal management of risk factors. In conclusion, this statement reinforces evidence for Lp(a) as a causal risk factor for cardiovascular outcomes. Trials of specific Lp(a)-lowering treatments are critical to confirm clinical benefit for cardiovascular disease and aortic valve stenosis.

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.

Glucose metabolism status modifies the relationship between lipoprotein(a) and carotid plaques in individuals with fatty liver disease

BACKGROUND AND AIMS

Glucose and lipoprotein(a) [Lp(a)] have been recognized risk factors for atherosclerosis. The impact of both factors on fatty liver patients has not been studied. The aim of this study is to explore the role of high-level Lp(a) and different glucose metabolism statuses on carotid plaques in fatty liver patients.

METHODS

We selected 4,335 fatty liver patients in this cross-sectional study. The diagnosis of fatty liver disease and carotid plaques was made by ultrasound. Participants were divided into four groups based on glucose metabolism status (normal glucose regulation [NGR], lower bound of impaired fasting glucose [IFG-L], higher bound of impaired fasting glucose [IFG-H], diabetes mellitus [DM]) and then categorized into 12 subgroups according to Lp(a) concentrations. The association between variables was estimated by odds ratio (OR).

RESULTS

Carotid plaques were present in 1,613 (37.2%) fatty liver patients. Lp(a)≥30 mg/dL was associated with high risk of carotid plaques in those patients with IFG-L, IFG-H and DM (OR 1.934 [95% CI 1.033-3.618], 2.667 [1.378-5.162], 4.000 [2.219-7.210], respectively; p<0.05). Fatty liver patients with DM plus Lp(a)<10 mg/dL and 10≤Lp(a)<30 mg/dL were more vulnerable to carotid plaques (OR 1.563 [95% CI 1.090-2.241], 1.930 [1.279-2.914]), respectively, p<0.05).

CONCLUSIONS

Our study first suggested that high-level Lp(a) may raise the risk of carotid plaques in fatty liver patients with not only diabetes but also IFG, manifesting that Lp(a) may be helpful for the early discovery of subclinical atherosclerosis in fatty liver patients with impaired glucose metabolism.

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.

Genetics of Lipoprotein(a): Cardiovascular Disease and Future Therapy

PURPOSE OF REVIEW

Lipoprotein(a) levels are determined 80-90% by genetics and differ by up to 1000-fold between individuals. This review discusses the most recent literature on lipoprotein(a) as a risk factor for cardiovascular disease, as well as future lipoprotein(a)lowering therapies.

RECENT FINDINGS

Over the past few decades, numerous studies have observed that high lipoprotein(a) levels are associated observationally and causally through human genetics with increased risk of cardiovascular disease. Also, the development of safe and effective therapies to lower lipoprotein(a) is ongoing, most importantly using antisense oligonucleotides to prevent production of lipoprotein(a). Finally, both observational and genetic studies have estimated the extent to which lowering of lipoprotein(a) is needed to obtain a clinically meaningful reduction in the risk of cardiovascular disease. Lipoprotein(a) is a causal risk factor for cardiovascular disease; however, currently no approved safe and effective therapy is available to lower lipoprotein(a) levels. That said, promising randomized studies using antisense oligonucleotides show up to 80% reductions in lipoprotein(a), reductions that hopefully will result in lowering the risk of cardiovascular disease as presently tested in the ongoing HORIZON phase 3 trial.

Relation of Lipoprotein(a) Levels to Incident Type 2 Diabetes and Modification by Alirocumab Treatment

OBJECTIVE

In observational data, lower levels of lipoprotein(a) have been associated with greater prevalence of type 2 diabetes. Whether pharmacologic lowering of lipoprotein(a) influences incident type 2 diabetes is unknown. We determined the relationship of lipoprotein(a) concentration with incident type 2 diabetes and effects of treatment with alirocumab, a PCSK9 inhibitor.

RESEARCH DESIGN AND METHODS

In the ODYSSEY OUTCOMES trial alirocumab was compared with placebo in patients with acute coronary syndrome. Incident diabetes was determined from laboratory, medication, and adverse event data.

RESULTS

Among 13,480 patients without diabetes at baseline, 1,324 developed type 2 diabetes over a median 2.7 years. Median baseline lipoprotein(a) was 21.9 mg/dL. With placebo, 10 mg/dL lower baseline lipoprotein(a) was associated with hazard ratio 1.04 (95% CI 1.02-1.06, P < 0.001) for incident type 2 diabetes. Alirocumab reduced lipoprotein(a) by a median 23.2% with greater absolute reductions from higher baseline levels and no overall effect on incident type 2 diabetes (hazard ratio 0.95, 95% CI 0.85-1.05). At low baseline lipoprotein(a) levels, alirocumab tended to reduce incident type 2 diabetes, while at high baseline lipoprotein(a) alirocumab tended to increase incident type 2 diabetes compared with placebo (treatment-baseline lipoprotein(a) interaction P = 0.006). In the alirocumab group, a 10 mg/dL decrease in lipoprotein(a) from baseline was associated with hazard ratio 1.07 (95% CI 1.03-1.12; P = 0.0002) for incident type 2 diabetes.

CONCLUSIONS

In patients with acute coronary syndrome, baseline lipoprotein(a) concentration associated inversely with incident type 2 diabetes. Alirocumab had neutral overall effect on incident type 2 diabetes. However, treatment-related reductions in lipoprotein(a), more pronounced from high baseline levels, were associated with increased risk of incident type 2 diabetes. Whether these findings pertain to other therapies that reduce lipoprotein(a) is undetermined.

Lipoprotein(a) concentration is associated with risk of type 2 diabetes and cardiovascular events in a Chinese population with very high cardiovascular risk

PURPOSE

Evidences have shown that elevated lipoprotein(a) [Lp(a)] levels were associated with a lower risk of type 2 diabetes, but a higher risk of cardiovascular events in general populations. We aim to demonstrate the effect of Lp(a) concentrations on type 2 diabetes and cardiovascular events in a Chinese population with very high cardiovascular risk.

METHODS

Seven hundred ninety-eight participants who underwent coronary angiography between March and November 2013 with normal glucose metabolism were followed up from July to December 2018.

RESULTS

Five hundred thirty-five participants completed follow-up, and 395 of them had blood glucose data. Among 395 participants with blood glucose data, a total of 28 incident type 2 diabetes were identified during a median follow-up period of 4.42 years. Compared with the patients in the lowest tertile of Lp(a), the multifactorial adjusted HR for type 2 diabetes was 0.29 in the highest tertile (95% confidence intervals (CI) 0.10-0.89; P for trend = 0.03). Among 535 patients who completed follow-up, a total of 80 cases of major adverse cardiovascular events (MACE) were identified during a median follow-up period of 5.08 years. Compared with the patients in the lowest tertile of Lp(a), the multifactorial adjusted HR for MACE was 1.95 in the highest tertile (95% CI 1.05-3.65; P for trend = 0.03).

CONCLUSIONS

Elevated Lp(a) levels were associated with a lower risk of type 2 diabetes, but a higher risk of cardiovascular events in a Chinese population with very high cardiovascular risk.