Non-fasting lipids and risk of cardiovascular disease in patients with diabetes mellitus

In-depth triacylglycerol profiling using MS3 Q-Trap mass spectrometry

Total triacylglycerol (TAG) level is a key clinical marker of metabolic and cardiovascular diseases. However, the roles of individual TAGs have not been thoroughly explored in part due to their extreme structural complexity. We present a targeted mass spectrometry-based method combining multiple reaction monitoring (MRM) and multiple stage mass spectrometry (MS³) for the comprehensive qualitative and semiquantitative profiling of TAGs. This method referred as TriP-MS3 - triacylglycerol profiling using MS³ - screens for more than 6,700 TAG species in a fully automated fashion. TriP-MS3 demonstrated excellent reproducibility (median interday CV ∼ 0.15) and linearity (median R² = 0.978) and detected 285 individual TAG species in human plasma. The semiquantitative accuracy of the method was validated by comparison with a state-of-the-art reverse phase liquid chromatography (RPLC)-MS (R² = 0.83), which is the most commonly used approach for TAGs profiling. Finally, we demonstrate the utility and the versatility of the method by characterizing the effects of a fatty acid desaturase inhibitor on TAG profiles in vitro and by profiling TAGs in Caenorhabditis elegans.

Effects of Acute Cocoa Supplementation on Postprandial Apolipoproteins, Lipoprotein Subclasses, and Inflammatory Biomarkers in Adults with Type 2 Diabetes after a High-Fat Meal

Dyslipidemia and inflammation exacerbate postprandial metabolic stress in people with diabetes. Acute dietary supplementation with polyphenols shows promise in improving postprandial metabolic stress in type 2 diabetes (T2D). Cocoa is a rich source of dietary polyphenols with demonstrated cardioprotective effects in adults without diabetes. To date, the acute effects of cocoa on postprandial lipids and inflammation have received little attention in the presence of T2D. This report expands on our earlier observation that polyphenol-rich cocoa, given as a beverage with a fast-food-style, high-fat breakfast, increased postprandial high-density lipoprotein-cholesterol (HDL-C) in adults with T2D. We now test whether polyphenol-rich cocoa modulated postprandial apolipoproteins (Apo-A1, B), non-esterified fatty acids, nuclear magnetic resonance (NMR)-derived lipoprotein subclass profiles, and select biomarkers of inflammation following the same dietary challenge. We found that cocoa decreased NMR-derived concentrations of total very low-density lipoprotein and chylomicron particles and increased the concentration of total HDL particles over the 6-hour postprandial phase. Serum interleukin-18 was decreased by cocoa vs. placebo. Thus, polyphenol-rich cocoa may alleviate postprandial dyslipidemia and inflammation following a high-fat dietary challenge in adults with T2D. The study was registered at clinicaltrials.gov as NCT01886989.

Fasting and postprandial lipid parameters: A comparative evaluation of cardiovascular risk assessment in prediabetes and diabetes

Context:

Dyslipidemia plays a crucial role in atherogenesis, in both prediabetes and diabetes. There persists a lacuna in the evaluation of postprandial lipid parameters in prediabetes.

Aims:

To comparatively evaluate fasting and postprandial blood lipid parameters and atherogenic lipid ratios for cardiovascular risk assessment, in prediabetes and diabetes.

Materials and Methods:

Fifty-one patients diagnosed with diabetes mellitus and thirty-two with prediabetes were selected for the study. Lipid profile and blood glucose were analyzed in fasting and postprandial blood samples.

Statistical Analysis Used:

Kolmogorov–Smirnov test, Shapiro–Wilk test, one-way ANOVA, and Pearson's regression analysis were applied.

Results:

Postprandially, triglycerides (TG) was increased significantly in diabetes compared to controls (P < 0.01) and prediabetics (P < 0.05). Among the lipid ratios, triglyceride/high density lipoprotein (TG/HDLc) was significantly increased postprandially in diabetes compared to controls (P < 0.05). A comparative analysis of fasting and postprandial parameters within each group showed a significant increase in postprandial TG/HDLc compared to the fasting state in prediabetes (P < 0.001) and diabetes (P < 0.001). Postprandial TG (P < 0.01) and TG/HDLc (P < 0.01) showed a stronger correlation with HbA_1c compared to fasting TG (P < 0.05) and TG/HDLc (P > 0.05). The prevalence of dyslipidemia and insulin resistance was higher in postprandial state than the fasting state in prediabetes and diabetes.

Conclusions:

Postprandial TG and the TG/HDLc reflect lipid abnormalities than the corresponding fasting variables in diabetes and prediabetes. Postprandial TG and TG/HDLc are better reflectors of cardiovascular status in prediabetes and diabetes.

Update on the laboratory investigation of dyslipidemias

The role of the clinical laboratory is evolving to provide more information to clinicians to assess cardiovascular disease (CVD) risk and target therapy more effectively. Current routine methods to measure LDL-cholesterol (LDL-C), the Friedewald calculation, ultracentrifugation, electrophoresis and homogeneous direct methods have established limitations. Studies suggest that LDL and HDL size or particle concentration are alternative methods to predict future CVD risk. At this time there is no consensus role for lipoprotein particle or subclasses in CVD risk assessment. LDL and HDL particle concentration are measured by several methods, namely gradient gel electrophoresis, ultracentrifugation-vertical auto profile, nuclear magnetic resonance and ion mobility. It has been suggested that HDL functional assays may be better predictors of CVD risk. To assess the issue of lipoprotein subclasses/particles and HDL function as potential CVD risk markers robust, simple, validated analytical methods are required. In patients with small dense LDL particles, even a perfect measure of LDL-C will not reflect LDL particle concentration. Non-HDL-C is an alternative measurement and includes VLDL and CM remnant cholesterol and LDL-C. However, apolipoprotein B measurement may more accurately reflect LDL particle numbers. Non-fasting lipid measurements have many practical advantages. Defining thresholds for treatment with new measurements of CVD risk remain a challenge. In families with genetic variants, ApoCIII and lipoprotein (a) may be additional risk factors. Recognition of familial causes of dyslipidemias and diagnosis in childhood will result in early treatment. This review discusses the limitations in current laboratory technologies to predict CVD risk and reviews the evidence for emergent approaches using newer biomarkers in clinical practice.

Apolipoprotein C-III and High-Density Lipoprotein Subspecies Defined by Apolipoprotein C-III in Relation to Diabetes Risk

Apolipoprotein C-III (apoC-III) is a potentially novel biomarker that may play an important role in the pathogenesis of diabetes, particularly when present on the surface of high-density lipoprotein (HDL). In a case-cohort study carried out among 434 incident diabetes cases occurring before 2007 and 3,101 noncases in the Danish Diet, Cancer, and Health Study, we examined associations of baseline (1993-1997) plasma concentrations of apoC-III and subspecies of HDL defined by the presence or absence of apoC-III with risk of diabetes using Cox regression. ApoC-III was strongly associated with risk of diabetes (for top quintile vs. bottom quintile, hazard ratio (HR) = 3.43, 95% confidence interval (CI): 1.75, 6.70; P-trend < 0.001). The cholesterol concentration of HDL (HDL cholesterol (HDL-C)) without apoC-III was inversely associated with risk of diabetes (HR = 0.48, 95% CI: 0.27, 0.85; P-trend = 0.002), more so than total HDL-C (HR = 0.60, 95% CI: 0.35, 1.03; P-trend = 0.04), whereas HDL-C with apoC-III was not associated (HR = 1.05, 95% CI: 0.50, 2.21; P-trend = 0.44) (for HDL-C with apoC-III vs. HDL-C without apoC-III, P-heterogeneity = 0.002). ApoC-III itself is a strong risk marker for diabetes, and its presence on HDL may impair the antidiabetogenic properties of HDL. ApoC-III has potential to be a therapeutic target for the prevention of diabetes.

The prevalence of hypertension in relation with the normal albuminuria range in type 2 diabetes mellitus within the South Korean population: The Korean National Health and Nutrition Examination Survey, 2011-2012

AIMS

The coexistence of hypertension (HTN) and diabetes mellitus (DM) increases the risk of cardiovascular disease. In some studies, normal albuminuria has also been associated with cardiovascular disease and HTN. Therefore, we examined the relationships between albuminuria and the prevalence of HTN and its control rate in type 2 DM patients.

RESULTS

We analyzed data from the 2011-2012 Korea National Health and Nutrition Examination Survey, and 1188 subjects with type 2 DM were included in the study. We divided albuminuria into 3 albuminuria tertiles (T): T1: <4.82mg/g; T2: 4.82-17.56mg/g; and T3: ≥17.56mg/g. The systolic and diastolic blood pressure were positively correlated with the albumin to creatinine ratio (ACR) after adjusting for all covariates (P<0.001). Type 2 DM subjects with hypertension had more ACR T3 (odds ratio=2.018, 95% confidence interval=1.445-2.818) than subjects without HTN. Subjects with controlled HTN had less ACR T3 than subjects without controlled HTN (odds ratio=0.566, 95% confidence interval=0.384-0.836). When, we redivided albuminuria by <10, 10-30 (high normal albuminuria), 30-300mg/g (microalbuminuria), and 300mg/g≤(macroalbuminuria), the odds ratio for high normal albuminuria and microalbuminuria was 1.52 and 2.24, respectively in the presence of HTN, however, high normal albuminuria was not associated with HTN control.

CONCLUSIONS

In conclusion, albuminuria within the high normal range was associated with the prevalence of HTN in South Korean patients with type 2 DM.

Serum lipid profile changes after successful treatment with electroconvulsive therapy in major depression: A prospective pilot trial

BACKGROUND

Cholesterol is reduced in depressed patients, however, these patients have a higher risk for cardiovascular diseases. Electroconvulsive therapy (ECT) is a highly effective treatment option for specific forms of depression. Like for other non-pharmacological therapies targeting depression such as psychotherapy or sleep deprivation, there is a lack of evidence about the effects on peripheral lipid parameters. Our objective was to study the impact of ECT as a non-pharmacological treatment on the peripheral lipid pattern in depressive patients.

METHOD

Peripheral lipid profile composition before and after a course of ECT was analysed in 27 non-fasting inpatients at a university psychiatric hospital with DSM-IV major depressive episode. For the impact of ECT treatment on each lipid parameter a multivariate repeated measurement regression analysis was performed and computed separately for every dependent variable.

RESULTS

Total Cholesterol and the cholesterol subtypes HDL and LDL were increased after the treatment compared to baseline. Apolipoprotein A1 was also increased after ECT, whereas apolipoprotein B was not. Indices for the prediction of cardiovascular diseases were unchanged after successful treatment by ECT. The reduction of depressive psychopathology negatively correlated with increases of HDL cholesterol and apolipoprotein A1.

LIMITATIONS

Subjects received several antidepressants and other psychotropic medication before and during the ECT.

CONCLUSIONS

In our preliminary pilot study ECT as a non-pharmacological, effective treatment of depression led to distinct effects on the peripheral lipid pattern.

The traditions and risks of fasting for lipid profiles in patients with diabetes

Fasting overnight has been traditionally recommended by clinicians when ordering laboratory tests for lipid profiles for the purposes of health screening or monitoring of the effects of lipid-lowering medications. Patients with diabetes are tested for lipid profiles at least annually. This deeply rooted tradition of fasting for lipid testing has recently been challenged. Several studies have shown little benefit obtained by testing lipids in fasting compared with postprandial states. Furthermore, recent studies have shown the importance of postprandial lipid spikes in the pathogenesis of cardiovascular disease. At the same time, recent reports have alerted the medical community to the risk of hypoglycemia in patients with diabetes on antidiabetic medications (particularly insulin and sulfonylureas) who are asked to fast for lab tests. This article reviews the literature on these emerging issues in lipid testing in patients with diabetes, and offers recommendations for lipid testing in these patients in view of these emerging discussions.

Prognostic value of fasting versus nonfasting low-density lipoprotein cholesterol levels on long-term mortality: insight from the National Health and Nutrition Examination Survey III (NHANES-III)

BACKGROUND

National and international guidelines recommend fasting lipid panel measurement for risk stratification of patients for prevention of cardiovascular events. However, the prognostic value of fasting versus nonfasting low-density lipoprotein cholesterol (LDL-C) is uncertain.

METHODS AND RESULTS

Patients enrolled in the National Health and Nutrition Examination Survey III (NHANES-III), a nationally representative cross-sectional survey performed from 1988 to 1994, were stratified on the basis of fasting status (≥8 or <8 hours) and followed for a mean of 14.0 (±0.22) years. Propensity score matching was used to assemble fasting and nonfasting cohorts with similar baseline characteristics. The risk of outcomes as a function of LDL-C and fasting status was assessed with the use of receiver operating characteristic curves and bootstrapping methods. The interaction between fasting status and LDL-C was assessed with Cox proportional hazards modeling. Primary outcome was all-cause mortality. Secondary outcome was cardiovascular mortality. One-to-one matching based on propensity score yielded 4299 pairs of fasting and nonfasting individuals. For the primary outcome, fasting LDL-C yielded prognostic value similar to that for nonfasting LDL-C (C statistic=0.59 [95% confidence interval, 0.57-0.61] versus 0.58 [95% confidence interval, 0.56-0.60]; P=0.73), and LDL-C by fasting status interaction term in the Cox proportional hazards model was not significant (Pinteraction=0.11). Similar results were seen for the secondary outcome (fasting versus nonfasting C statistic=0.62 [95% confidence interval, 0.60-0.66] versus 0.62 [95% confidence interval, 0.60-0.66]; P=0.96; Pinteraction=0.34).

CONCLUSIONS

Nonfasting LDL-C has prognostic value similar to that of fasting LDL-C. National and international agencies should consider reevaluating the recommendation that patients fast before obtaining a lipid panel.

Prevalence, awareness, treatment and control of hypertension in adults with diagnosed diabetes: the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

We evaluated the prevalence, awareness, treatment and control of hypertension in Korean adults with diagnosed diabetes using nationally representative data. Among subjects aged ≥30 years who participated in the Fourth Korea National Health and Nutrition Examination Survey in 2007 and 2008, a total of 745 subjects (336 men and 409 women) with a previous diagnosis of diabetes mellitus were analyzed. The prevalence of hypertension in adults with diagnosed diabetes was 55.5%. The rates of awareness, treatment and control were 88.0, 94.2, and 30.8%, respectively. Compared with the general population, the prevalence of hypertension in adults with diagnosed diabetes was higher in all age groups in both genders. Factors independently associated with a high prevalence of hypertension included being male, increasing age, single, <9 years of education, the presence of chronic kidney disease risk, hypercholesterolemia (≥240 mg dl(-1)) and high body mass index (≥25 kg m(-2)). Regular medical screening was positively associated with hypertension control, whereas a high triglyceride level (≥150 mg dl(-1)) was inversely associated. A high prevalence and a low control rate of hypertension in adults with diagnosed diabetes suggest that stringent efforts are needed to control blood pressure in diabetic patients.

Prediction models for risk of developing type 2 diabetes: systematic literature search and independent external validation study

OBJECTIVE

To identify existing prediction models for the risk of development of type 2 diabetes and to externally validate them in a large independent cohort.

DATA SOURCES

Systematic search of English, German, and Dutch literature in PubMed until February 2011 to identify prediction models for diabetes.

DESIGN

Performance of the models was assessed in terms of discrimination (C statistic) and calibration (calibration plots and Hosmer-Lemeshow test).The validation study was a prospective cohort study, with a case cohort study in a random subcohort.

SETTING

Models were applied to the Dutch cohort of the European Prospective Investigation into Cancer and Nutrition cohort study (EPIC-NL).

PARTICIPANTS

38,379 people aged 20-70 with no diabetes at baseline, 2506 of whom made up the random subcohort.

OUTCOME MEASURE

Incident type 2 diabetes.

RESULTS

The review identified 16 studies containing 25 prediction models. We considered 12 models as basic because they were based on variables that can be assessed non-invasively and 13 models as extended because they additionally included conventional biomarkers such as glucose concentration. During a median follow-up of 10.2 years there were 924 cases in the full EPIC-NL cohort and 79 in the random subcohort. The C statistic for the basic models ranged from 0.74 (95% confidence interval 0.73 to 0.75) to 0.84 (0.82 to 0.85) for risk at 7.5 years. For prediction models including biomarkers the C statistic ranged from 0.81 (0.80 to 0.83) to 0.93 (0.92 to 0.94). Most prediction models overestimated the observed risk of diabetes, particularly at higher observed risks. After adjustment for differences in incidence of diabetes, calibration improved considerably.

CONCLUSIONS

Most basic prediction models can identify people at high risk of developing diabetes in a time frame of five to 10 years. Models including biomarkers classified cases slightly better than basic ones. Most models overestimated the actual risk of diabetes. Existing prediction models therefore perform well to identify those at high risk, but cannot sufficiently quantify actual risk of future diabetes.

Parental history of type 2 diabetes and cardiometabolic biomarkers in offspring

BACKGROUND

Parental history of type 2 diabetes (T2D) is associated with cardiometabolic risk. We aimed to investigate the associations of parental history of T2D with cardiometabolic biomarkers and to subsequently investigate to what extent these putative associations were explained by modifiable factors.

MATERIALS AND METHODS

Cross-sectionally, we analysed a random sample of 2001 participants without T2D (20-70 years) from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL). Plasma levels of 12 biomarkers - total, HDL and LDL-cholesterol, triglycerides, HbA1c, gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT), asparate aminotransferase (AST), albumin, uric acid, creatinine and high-sensitivity CRP (hs-CRP) - were assessed according to categories of parental history of T2D.

RESULTS

In age and sex-adjusted analyses, offspring with parental history of T2D had significantly higher ALT [β = 0·074; 95% confidence interval (95%CI), 0·023-0·126] and AST levels (β = 0·033; 95%CI, 0·001 to 0·066) and a trend towards higher HbA1c (β = 0·011; 95%CI, -0·001 to 0·024) and GGT (β = 0·049; 95%CI, -0·015 to 0·112) levels. Adjustment for diet, smoking, alcohol intake, physical activity and educational level modestly attenuated the magnitude of these associations, but they remained significant for ALT and borderline significant for AST. After further adjustment for adiposity, additional attenuation was observed, but the association remained significant for ALT. Only maternal history of T2D was associated with higher ALT levels. T2D in both parents was associated with increased levels of all liver enzymes, but the association remained significant for GGT after adjustment for adiposity. Overall, the modifiable factors explained 21·2-45·4% of these associations. The contribution of adiposity was 18·2-38·9%.

CONCLUSION

We conclude that parental history of T2D was associated with higher non-fasting levels of liver enzymes in a general population without T2D. Adiposity substantially contributed to these associations. The contribution of diet and lifestyle factors was modest.

Postprandial dyslipidaemia and diabetes: mechanistic and therapeutic aspects

PURPOSE OF REVIEW

There has been a resurgence of interest in the role of triglyceride-rich lipoproteins in the development of atherosclerosis and cardiovascular disease, and this is particularly relevant to diabetes mellitus and the postprandial state.

RECENT FINDINGS

Recent evidence suggests that insulin resistance in diabetes induces postprandial dyslipidemia by increasing the enterocytic production of chylomicrons and their remnant particles, but an impaired clearance capacity is also involved. Postprandial dyslipidaemia in diabetes induces oxidative stress, inflammation and endothelial dysfunction and this may be compounded by dysglycaemia. New guidelines for managing hypertriglyceridaemia in diabetes have been published, first-line therapies being improved glycaemic control, treatment of other secondary causes of dyslipidaemia and statin therapy, followed by judicious use of fibrates, n-3 fatty acids or niacin. A new role for incretin-based therapies in regulating dyslipidaemia has been identified.

SUMMARY

Postprandial dyslipidaemia is a pivotal mechanism whereby diabetes can induce and accelerate atherosclerosis. Regulating the plasma concentrations of triglyceride-rich lipoproteins may decrease the cardiovascular complications of diabetes. The mechanisms of action of incretin-based treatments on dyslipidaemia and endothelial dysfunction need further investigation. The efficacy of new therapies targeted at postprandial dysmetabolism in diabetes need to be confirmed, against best current levels of care, in clinical endpoint trials.

Gamma-glutamyltransferase, cardiovascular disease and mortality in individuals with diabetes mellitus

BACKGROUND

Increased plasma activity of gamma-glutamyltransferase (GGT) is associated with cardiovascular diseases (CVD) and mortality in the general population. We investigated the association between GGT, CVD and mortality in individuals with diabetes mellitus.

METHODS

Data used were from 1280 participants, aged 35-70 years, with a confirmed diagnosis of diabetes mellitus in the European Prospective Investigation into Cancer and Nutrition in Potsdam (Germany), Bilthoven and Utrecht (the Netherlands). Multivariate hazard ratios (HR) and 95% confidence intervals (CI) for CVD (non-fatal and fatal events) and overall mortality were estimated using sex-specific quartiles of GGT.

RESULTS

After 8.2 years follow-up, 108 incident CVD cases and 84 deaths were observed. Participants with high GGT activity had an increased mortality risk: HR in the highest quartile was 3.96 (95% CI 1.74, 9.00). This association was in particular present in former and current smokers, younger persons and those with a higher waist-height ratio and alcohol consumption. No associations were observed for non-fatal CVD and non-fatal and fatal CVD events combined.

CONCLUSIONS

Higher GGT plasma activity is associated with increased all-cause mortality in individuals with diabetes.

Why, when and how should hypertriglyceridemia be treated in the high-risk cardiovascular patient?

Recent epidemiology attests that hypertriglyceridemia may be a causal risk factor for cardiovascular disease (CVD). The specific atherogenicity of hypertriglyceridemia relates to the accumulation in plasma of triglyceride-rich lipoprotein remnants. Hypertriglyceridemia also drives a 'global' atherogenic dyslipidemic profile, which is frequent in high-risk cardiovascular patients, such as Type 2 diabetics. Elevated triglyceride in fasting or nonfasting blood samples should be a trigger for assessing atherogenic components of the lipid profile, particularly HDL-cholesterol, non-HDL-cholesterol and apoB. Residual risk of CVD remains high in statin-treated diabetic patients owing to persistent atherogenic dyslipidemia, which is not fully corrected by these agents nor by the addition of ezetimibe. Hypertriglyceridemia may then be targeted with niacin, fibrates or n-3 fatty acids, after correcting aggravating factors, especially obesity and hyperglycemia. Fibrates consistently decrease coronary events in dyslipidemic patients in outcome studies. New evidence supports adding fenofibrate to a statin in Type 2 diabetics with residual hypertriglyceridemia and low HDL-cholesterol; extrapolating from a recent meta-analysis, a 15% reduction in triglycerides could translate into a further 15% reduction in coronary events. Ongoing clinical trials may provide new evidence for adding niacin to a statin. The value of higher doses of n-3 fatty acids in reducing CVD risk remains to be demonstrated. The high triglyceride/low HDL nexus is an under-recognized risk factor for CVD that merits more detailed clinical assessment and treatment, particularly in patients with Type 2 diabetes already receiving a statin.