Visit-to-visit variability in LDL- and HDL-cholesterol is associated with adverse events after ST-segment elevation myocardial infarction: A 5-year follow-up study

Lipid Variability Induces Endothelial Dysfunction by Increasing Inflammation and Oxidative Stress

BACKGRUOUND

This study investigates the impact of fluctuating lipid levels on endothelial dysfunction.

METHODS

Human aortic and umbilical vein endothelial cells were cultured under varying palmitic acid (PA) concentrations: 0, 50, and 100 μM, and in a variability group alternating between 0 and 100 μM PA every 8 hours for 48 hours. In the lipid variability group, cells were exposed to 100 μM PA during the final 8 hours before analysis. We assessed inflammation using real-time polymerase chain reaction, Western blot, and cytokine enzyme-linked immunosorbent assay (ELISA); reactive oxygen species (ROS) levels with dichlorofluorescin diacetate assay; mitochondrial function through oxygen consumption rates via XF24 flux analyzer; and endothelial cell functionality via wound healing and cell adhesion assays. Cell viability was evaluated using the MTT assay.

RESULTS

Variable PA levels significantly upregulated inflammatory genes and adhesion molecules (Il6, Mcp1, Icam, Vcam, E-selectin, iNos) at both transcriptomic and protein levels in human endothelial cells. Oscillating lipid levels reduced basal respiration, adenosine triphosphate synthesis, and maximal respiration, indicating mitochondrial dysfunction. This lipid variability also elevated ROS levels, contributing to a chronic inflammatory state. Functionally, these changes impaired cell migration and increased monocyte adhesion, and induced endothelial apoptosis, evidenced by reduced cell viability, increased BAX, and decreased BCL2 expression.

CONCLUSION

Lipid variability induce endothelial dysfunction by elevating inflammation and oxidative stress, providing mechanistic insights into how lipid variability increases cardiovascular risk.

Variability in Plasma Lipids Between Intensive Statin Therapy and Conventional-Dose Statins Combined with Ezetimibe Therapy in Patients with Coronary Atherosclerosis Disease

Dyslipidemia has been widely recognized as a significant risk factor for coronary atherosclerosis disease (CAD). In fact, lipid variability has emerged as a more reliable predictor of cardiovascular events. In this study, we aimed to examine the variability in plasma lipids under two different lipid-lowering regimens (intensive statin therapy versus the combination of conventional-dose statins with ezetimibe). In total, we have retrospectively examined 1275 patients with CAD from January 2009 to April 2019 and divided them into two groups: intensive statin group and conventional-dose statins combined with ezetimibe group. All patients were followed up for at least 1 year. Lipid variability was verified by standard deviation (SD), coefficient of variation (CV), and variability independent of mean (VIM) triple methods. Multiple linear regression and subgroup analyses were performed. In the overall participants, the mean age was 62.3 ± 10.4 years old, and 72.8% were male. Multivariate linear regression analysis indicated that the intensive statin group had lower variability in terms of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C) in all SD, CV, and VIM triple methods than statins combined with ezetimibe group (P for all <0.05). Similar results were established in the subgroup analyses based on atorvastatin or rosuvastatin, diabetes mellitus or not, and hypertension or not (P for all < 0.05). Thus, we can conclude that intensive statin therapy could contribute in lowering lipid variability than conventional-dose statins combined with ezetimibe therapy among patients with CAD.

Association of total cholesterol variability with risk of venous thromboembolism: A nationwide cohort study

BACKGROUND

The effects of total cholesterol (TC) on coagulation and hemostatic systems could contribute to the development of venous thromboembolism (VTE). We investigated this possible association using TC variability.

METHODS

From the Korean NHIS-HEALS database, 1,236,589 participants with health screenings between 2003 and 2008 were included. TC variability was assessed using various parameters, including the coefficient of variation (CV), standard deviation (SD), and variability independent of mean (VIM). Occurrence of VTE was established by identifying at least two medical claims with a diagnostic code including various types of VTE: deep vein thrombosis (DVT) (I80.2-80.3), pulmonary embolism (PE) (I26, I26.0, I26.9), intraabdominal VTE (I81, I82, I82.2-82.3), and other VTE (I82.8-82.9).

RESULTS

Throughout the study's median follow-up period of 12.4 years (interquartile range 12.2-12.6) years, TC levels were assessed a total of 5,702,800 times. VTE occurred in 11,769 (1.08%) patients (DVT (4,708 (0.43%)), PE (3,109 (0.29%)), intraabdominal VTE (5,215 (0.48%)), and other VTE (4,794, (0.44%)). As a result, there was gradual association was observed between higher TC variability and occurrence of VTE. Multivariable analysis showed that quartile of TC variability using CV showed a positive correlation with the occurrence of VTE (adjusted hazard ratio (the highest versus lowest quartile), 1.14, 95% confidence interval, 1.08-1.20, p < 0.001). This result remained consistent applying to SD and VIM. In addition, higher quartile of TC variability was consistently associated with the development of various types of VTE in subgroup analysis.

CONCLUSIONS

Increased TC variability may be associated with increased VTE risk. This analysis highlights the importance of maintaining stable TC levels to prevent the development of VTE.

AT1R gene rs389566 polymorphism contributes to MACCEs in hypertension patients

OBJECTIVE

To investigate the possible association between AT1R gene polymorphisms and major adverse cardiovascular and cerebrovascular events (MACCEs) in hypertension patients combined with or without coronary artery disease (CAD) in Xinjiang.

METHODS

374 CAD patients and 341 non-CAD individuals were enrolled as study participants and all of them have a hypertension diagnosis. AT1R gene polymorphisms were genotyped by SNPscan™ typing assays. During the follow-up in the clinic or by telephone interview, MACCEs were recorded. Kaplan-Meier curves and Cox survival analyses were used to explore the association between AT1R gene polymorphisms and the occurrence of MACCEs.

RESULTS

AT1R gene rs389566 was associated with MACCEs. The TT genotype of the AT1R gene rs389566 had a significantly higher probability of MACCEs than the AA + AT genotype (75.2% vs. 24.8%, P = 0.033). Older age (OR = 1.028, 95% CI: 1.009-1.0047, P = 0.003) and TT genotype of rs389566 (OR = 1.770, 95% CI: 1.148-2.729, P = 0.01) were risk factors of MACCEs. AT1R gene rs389566 TT genotype may be a predisposing factor for the occurrence of MACCEs in hypertensive patients.

CONCLUSION

We should also pay more attention to the prevent of MACCEs in hypertension patients combined with CAD. Especially those elderly hypertensive patients carrying AT1R rs389566 TT genotype requires avoidance of unhealthy lifestyle, better management of blood pressure control and reduce the occurrence of MACCEs.

Effects of metabolic parameters' variability on cardiovascular outcomes in diabetic patients

BACKGROUND

Metabolic abnormalities such as dyslipidemia, glucose and high blood pressure are common in diabetic patients. Visit-to-visit variabilities in these measures have been reported as potential residual cardiovascular risk factors. However, the relationship between these variabilities and their effects on cardiovascular prognosis have not been studied.

METHODS

A total of 22,310 diabetic patients with ≥ 3 measurements of systolic blood pressure (SBP), blood glucose, total cholesterol (TC), and triglyceride (TG) levels during a minimum of three years at three tertiary general hospitals were selected. They were divided into high/low variability groups for each variable based on the coefficient of variation (CV) values. The primary outcome was the incidence of major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, and stroke.

RESULTS

All high CV groups had a higher incidence of MACE than those with low CV (6.0% vs. 2.5% for SBP-CV groups, 5.5% vs. 3.0% for TC-CV groups, 4.7% vs. 3.8% for TG-CV groups, 5.8% vs. 2.7% for glucose-CV groups). In multivariable Cox regression analysis,, high SBP-CV (HR 1.79 [95% CI 1.54-2.07], p < 0.01), high TC-CV (HR 1.54 [95% CI 1.34-1.77], p < 0.01), high TG-CV (HR 1.15 [95% CI 1.01-1.31], p = 0.040) and high glucose-CV (HR 1.61 [95% CI 1.40-1.86], p < 0.01) were independent predictors of MACE.

CONCLUSION

Variability of SBP, TC, TG and glucose are important residual risk factors for cardiovascular events in diabetic patients.

Conventional Biomarkers for Predicting Clinical Outcomes in Patients with Heart Disease

Atherosclerosis is the main cause of cardiovascular disease worldwide. The progression of coronary atherosclerosis leads to coronary artery disease, with impaired blood flow to the myocardium and subsequent development of myocardial ischemia. Acute coronary syndromes and post-myocardial infarction heart failure are two of the most common complications of coronary artery disease and are associated with worse outcomes. In order to improve the management of patients with coronary artery disease and avoid major cardiovascular events, several risk assessment tools have been developed. Blood and imaging biomarkers, as well as clinical risk scores, are now available and validated for clinical practice, but research continues. The purpose of the current paper is to provide a review of recent findings regarding the use of humoral biomarkers for risk assessment in patients with heart disease.

Comparison of the effects of triglyceride variability and exposure estimate on clinical prognosis in diabetic patients

BACKGROUND

Hypertriglyceridemia is an important feature of dyslipidemia in type 1 and type 2 diabetic patients and associated with the development of atherosclerotic cardiovascular disease. Recently, variability of lipid profile has been suggested as a residual risk factor for cardiovascular disease. This study compared the clinical impact of serum triglyceride variability, and their cumulative exposure estimates on cardiovascular prognosis in diabetic patients.

METHODS

A total of 25,933 diabetic patients who had serum triglyceride levels measured at least 3 times and did not have underlying malignancy, myocardial infarction (MI), and stroke during the initial 3 years (modeling phase) were selected from three tertiary hospitals. They were divided into a high/low group depending on their coefficient of variation (CV) and cumulative exposure estimate (CEE). Incidence of major adverse event (MAE), a composite of all-cause death, MI, and stroke during the following 5 years were compared between groups by multivariable analysis after propensity score matching.

RESULTS

Although there was a slight difference, both the high CV group and the high CEE group had a higher cardiovascular risk profile including male-dominance, smoking, alcohol, dyslipidemia, and chronic kidney disease compared to the low groups. After the propensity score matching, the high CV group showed higher MAE incidence compared to the low CV group (9.1% vs 7.7%, p = 0.01). In contrast, there was no significant difference of MAE incidence between the high CEE group and the low CEE group (8.6% vs 9.1%, p = 0.44). After the multivariable analysis with further adjustment for potential residual confounding factors, the high CV was suggested as an independent risk predictor for MAE (HR 1.19 [95% CI 1.03-1.37]).

CONCLUSION

Visit-to-visit variability of triglyceride rather than their cumulative exposure is more strongly related to the incidence of MAE in diabetic patients.

Joint effect of visit-to-visit variability in LDL-cholesterol, HDL-cholesterol and HbA1c on cardiovascular and total mortality in patients with diabetes

BACKGROUND

We aimed to investigate the joint effect of visit-to-visit variability (VVV) in low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides and glycosylated hemoglobin (HbA1c) on cardiovascular mortality and total mortality in patients with diabetes.

METHODS

Among 5194 participants with type 2 diabetes enrolled in the ACCORD lipid trial, VVVs of LDL-C, triglycerides, HDL-C, and HbA1c were assessed from baseline to 2 years of follow-up and expressed as coefficient of variation (CV). The study outcomes included cardiovascular mortality and all-cause mortality.

RESULTS

Over a median follow-up of 3.0 years from the end of variability measurements at years 2, there were 305 (5.9%) cases of all-cause mortality, of which, 144 were cardiovascular causes. The positive relations between LDL-C CV and cardiovascular mortality were significantly stronger among participants with higher HDL-C CV (P for interaction = 0.023), and higher HbA1c CV (P for interaction = 0.015). However, there were no significant interactions between LDL-C CV and triglycerides CV (P for interaction = 0.591). Similar trends were found for all-cause mortality. Consistently, there were graded trends in the risk of mortality with the increasing numbers of higher CV of the three variables: LDL-C, HbA1c, and HDL-C (P for trend = 0.008 for cardiovascular mortality, and P for trend < 0.001 for all-cause mortality).

CONCLUSION

VVVs in LDL-C, HDL-C, and HbA1c may jointly affect the risks of cardiovascular and all-cause mortality in diabetes patients. Those with higher CVs of all three variables had the highest risks of cardiovascular and all-cause mortality.

Risk for Behçet's disease gauged via high-density lipoprotein cholesterol: a nationwide population-based study in Korea

Behçet’s disease (BD) is a chronic inflammatory disease. Low levels of plasma high-density lipoprotein cholesterol (HDL-C) are associated with Crohn’s disease, another chronic inflammatory disease. However, the effects of low HDL-C levels on BD are unclear. We investigated the effects of HDL-C levels, and variability therein, on the risk for BD. We used the Korean National Health Insurance System database to identify 5,587,754 adults without a history of BD who underwent ≥ 3 medical examinations between 2010 and 2013. Mean HDL-C levels at each visit were used to calculate variability independent of the mean (VIM) and the coefficient of variation (CV). There were 676 new cases of BD (0.012%). The risk for BD was increased in participants with highly variable and low mean HDL-C levels. In a multivariate-adjusted model, the hazard ratios (95% confidence intervals) for BD incidence were 1.335 (1.058–1.684) in a high mean/high VIM group, 1.527 (1.211–1.925) in a low mean/low VIM group, and 2.096 (1.67–2.63) in a low mean/high VIM group compared to a high mean/low VIM group. Low mean HDL-C levels, and high variability therein, are independent risk factors for BD.

Lipid Variability and Risk of Cardiovascular Diseases and All-Cause Mortality: A Systematic Review and Meta-Analysis of Cohort Studies

No consensus has yet been reached on the associations of lipid variability (LV) with cardiovascular diseases (CVDs) and all-cause mortality. We aimed to quantify the associations of different types and metrics of LV with CVDs and all-cause mortality. PubMed, Medline, and Embase databases were searched for eligible cohort studies published until 14 December 2021. Lipids included total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). Metrics of variability included standard deviation (SD), coefficient of variation (CV), and variation independent of the mean (VIM). The primary outcomes were CVDs and all-cause mortality. Random-effects meta-analysis was used to generate a summary of the relative risks (SRRs). Sources of heterogeneity were explored by subgroup analysis and meta-regression. A total of 11 articles based on seven cohorts were included. Participants in the top quartile of TC variability had an increased risk of CVDs (vs. bottom quartile: TC-CV: SRR 1.29, 95% CI 1.15-1.45; TC-SD: 1.28, 1.15-1.43; TC-VIM: 1.26, 1.13-1.41, respectively) and all-cause mortality (vs. bottom quartile: TC-CV: 1.28, 1.15-1.42; TC-SD: 1.32, 1.22-1.44; TC-VIM: 1.32, 1.25-1.40, respectively). Participants in the top quartile of HDL-C variability had an increased risk of CVDs (vs. bottom quartile: HDL-C-CV: 1.11, 1.07-1.15; HDL-C-SD: 1.18, 1.02-1.38; HDL-C-VIM: 1.18, 1.09-1.27, respectively) and all-cause mortality (vs. bottom quartile: HDL-C-CV: 1.29, 1.27-1.31; HDL-C-SD: 1.24, 1.09-1.41; HDL-C-VIM: 1.25, 1.22-1.27, respectively). LDL-C variability was also associated with an increased risk of CVDs (for top vs. bottom quartile; LDL-C-SD: 1.09, 1.02-1.17; LDL-C-VIM: 1.16, 1.02-1.32, respectively) and all-cause mortality (for top vs. bottom quartile; LDL-C-CV: 1.19, 1.04-1.36; LDL-C-SD: 1.17, 1.09-1.26, respectively). The relationships of TG variability with the risk of CVDs and all-cause mortality were inconclusive across different metrics. The effects of SRR became stronger when analyses were restricted to studies that adjusted for lipid-lowering medication and unadjusted for mean lipid levels. These findings indicate that the measurement and surveillance of lipid variability might have important clinical implications for risk assessment of CVDs and all-cause mortality.

Mean and Variability of Lipid Measurements and Risk for Development of Subclinical Left Ventricular Diastolic Dysfunction

BACKGROUND

Subclinical left ventricular diastolic dysfunction (LVDD) is an emerging consequence of increased insulin resistance, and dyslipidemia is one of the few correctable risk factors of LVDD. This study evaluated the role of mean and visit-to-visit variability of lipid measurements in risk of LVDD in a healthy population.

METHODS

This was a 3.7-year (interquartile range, 2.1 to 4.9) longitudinal cohort study including 2,817 adults (median age 55 years) with left ventricular ejection fraction >50% who underwent an annual or biannual health screening between January 2008 and July 2016. The mean, standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM), and average real variability of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (apoB), non-HDL-C, and triglycerides were obtained from three to six measurements during the 5 years preceding the first echocardiogram.

RESULTS

Among the 2,817 patients, 560 (19.9%) developed LVDD. The mean of no component of lipid measurements was associated with risk of LVDD. CV (hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.10 to 1.67), SD (HR, 1.27; 95% CI, 1.03 to 1.57), and VIM (HR, 1.26; 95% CI, 1.03 to 1.55) of LDL-C and all the variability parameters of apoB were significantly associated with development of LVDD. The association between CV-LDL and risk of LVDD did not have significant interaction with sex, increasing/decreasing trend at baseline, or use of stain and/or lipid-modifying agents.

CONCLUSION

The variability of LDL-C and apoB, rather than their mean, was associated with risk for LVDD.

Prognostic significance of visit-to-visit variability, and maximum and minimum LDL cholesterol in diabetes mellitus

BACKGROUND

Current guidelines for dyslipidemia management recommend that the LDL-C goal be lower than 70 mg/dL. The present study investigated the prognostic significance of visit-to-visit variability in LDL-C, and minimum and maximum LDL-C during follow-up in diabetes mellitus.

METHODS

The risk of outcomes in relation to visit-to-visit LDL-C variability was investigated in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Lipid trial. LDL-C variability indices were coefficient of variation (CV), variability independent of the mean (VIM), and average real variability (ARV). Multivariable Cox proportional hazards models were employed to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Compared with the placebo group (n=2667), the fenofibrate therapy group (n=2673) had a significantly (P<0.01) lower mean plasma triglyceride (152.5 vs. 178.6 mg/dL), and total cholesterol (158.3 vs.162.9 mg/dL) but a similar mean LDL-C during follow-up (88.2 vs. 88.6 mg/dL, P>0.05). All three variability indices were associated with primary outcome, total mortality and cardiovascular mortality both in the total population and in the fenofibrate therapy group but only with primary outcome in the placebo group. The minimum LDL-C but not the maximum during follow-up was significantly associated with various outcomes in the total population, fenofibrate therapy and placebo group. The minimum LDL-C during follow-up ≥70 mg/dL was associated with an increased risk for various outcomes.

CONCLUSIONS

Visit-to-visit variability in LDL-C was a strong predictor of outcomes, independent of mean LDL-C. Patients with LDL-C controlled to less than 70 mg/dL during follow-up might have a benign prognosis. ClinicalTrials.gov number: NCT00000620.

Elevation of Hemoglobin A1c Increases the Atherosclerotic Plaque Vulnerability and the Visit-to-Visit Variability of Lipid Profiles in Patients Who Underwent Elective Percutaneous Coronary Intervention

Background

Increased plaque vulnerability and higher lipid variability are causes of adverse cardiovascular events. Despite a close association between glucose and lipid metabolisms, the influence of elevated glycated hemoglobin A1c (HbA1c) on plaque vulnerability and lipid variability remains unclear.

Methods

Among subjects undergoing percutaneous coronary intervention (PCI) from 2009 through 2019, 366 patients received intravascular optical coherence tomography (OCT) assessment and 4,445 patients underwent the scheduled follow-ups within 1 year after PCI. Vulnerability features of culprit vessels were analyzed by OCT examination, including the assessment of lipid, macrophage, calcium, and minimal fibrous cap thickness (FCT). Visit-to-visit lipid variability was determined by different definitions including standard deviation (SD), coefficient of variation (CV), and variability independent of the mean (VIM). Multivariable linear regression analysis was used to verify the influence of HbA1c on plaque vulnerability features and lipid variability. Exploratory analyses were also performed in non-diabetic patients.

Results

Among enrolled subjects, the pre-procedure HbA1c was 5.90 ± 1.31%, and the average follow-up HbA1c was 5.98 ± 1.16%. By OCT assessment, multivariable linear regression analyses demonstrated that patients with elevated HbA1c had a thinner minimal FCT (β = −6.985, P = 0.048), greater lipid index (LI) (β = 226.299, P = 0.005), and higher macrophage index (β = 54.526, P = 0.045). Even in non-diabetic patients, elevated HbA1c also linearly decreased minimal FCT (β = −14.011, P = 0.036), increased LI (β = 290.048, P = 0.041) and macrophage index (β = 120.029, P = 0.048). Subsequently, scheduled follow-ups were performed during 1-year following PCI. Multivariable linear regression analyses proved that elevated average follow-up HbA1c levels increased the VIM of lipid profiles, including low-density lipoprotein cholesterol (β = 2.594, P < 0.001), high-density lipoprotein cholesterol (β = 0.461, P = 0.044), non-high-density lipoprotein cholesterol (β = 1.473, P < 0.001), total cholesterol (β = 0.947, P < 0.001), and triglyceride (β = 4.217, P < 0.001). The result was consistent in non-diabetic patients and was verified when SD and CV were used to estimate variability.

Conclusion

In patients undergoing elective PCI, elevated HbA1c increases the atherosclerotic plaque vulnerability and the visit-to-visit variability of lipid profiles, which is consistent in non-diabetic patients.

Genetic Determinants of Visit-to-Visit Lipid Variability: Genome-Wide Association Study in Statin-Naïve Korean Population

Background and Aim

There is a growing evidence that fluctuation in lipid profiles is important in cardiovascular outcomes. We aimed to identify single nucleotide polymorphism (SNP) variants associated with low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) variability in statin-naïve Korean subjects and evaluate their associations with coronary atherosclerosis.

Methods

In statin-naïve subjects from Gene-Environment of Interaction and phenotype cohort, we performed genome-wide association studies of lipid variability; the discovery (first) and replication (second) sets included 4,287 and 1,086 subjects, respectively. Coronary artery calcium (CAC) score and degree of coronary artery stenosis were used as outcome measures. Cholesterol variability was determined by standard deviation and average successive variability, and significant coronary atherosclerosis was defined as CAC score ≥400 or coronary stenosis ≥70%.

Results

Mean HDL-C and LDL-C level were 54 ± 12 and 123 ± 30 mg/dL in the first set and 53 ± 12 and 126 ± 29 mg/dL in the second set. APOA5 rs662799 and APOA5 rs2266788 were associated with LDL-C variability and PXDNL rs80056520, ALDH2 rs671, HECTD4 rs2074356, and CETP rs2303790 were SNPs associated for HDL-C variability. APOA5 rs662799 passed Bonferroni correction with p-value of 1.789 × 10⁻⁹. Among the SNPs associated with cholesterol variability, rs80056520 and rs2266788 variants were associated with CACS ≥400 and coronary stenosis ≥70% and rs662799 variant was associated with coronary stenosis ≥70%.

Conclusion

Two SNPs associated with LDL-C variability (APOA5 rs662799 and rs2266788) and one SNP associated with HDL-C variability (PXDNL rs80056520) were significantly associated with advanced coronary artery stenosis. Combining GWAS results with imaging parameters, our study may provide a deeper understanding of underlying pathogenic basis of the link between lipid variability and coronary atherosclerosis.

Association between Variability of Metabolic Risk Factors and Cardiometabolic Outcomes

Despite strenuous efforts to reduce cardiovascular disease (CVD) risk by improving cardiometabolic risk factors, such as glucose and cholesterol levels, and blood pressure, there is still residual risk even in patients reaching treatment targets. Recently, researchers have begun to focus on the variability of metabolic variables to remove residual risks. Several clinical trials and cohort studies have reported a relationship between the variability of metabolic parameters and CVDs. Herein, we review the literature regarding the effect of metabolic factor variability and CVD risk, and describe possible mechanisms and potential treatment perspectives for reducing cardiometabolic risk factor variability.

Two-Year Change in Serum Total Cholesterol Is Associated With Incident Ischemic Stroke: Results From the Kailuan Study

Background and Purpose: Compared with one single measurement, dynamic change of lipid parameter calculated by repeated measurements has been recognized as a potential biometric to make stroke risk assessments. Total cholesterol (TC) is an important risk factor for stroke, but the relationship between TC change and incident stroke has not been investigated thoroughly. We thus aimed to explore the association between 2-year TC change and the risk of incident stroke, both ischemic and hemorrhagic, in the general population. Methods: From June 2006 to October 2007, a total of 70,999 participants with complete TC value at baseline (2006-2007) and the second examination (2008-2009) were included in our study. The change of TC was calculated as the 2-year follow-up TC subtracting baseline TC. Cox proportional hazards regression analysis was used to evaluate the association between the tertile of TC change and risk of incident stroke and stroke subtypes. Results: A total of 2,815 cases of stroke events were identified with a median follow-up period of 9.0 years. After adjusting for baseline TC and confounding factors, 2-year TC change was independently associated with increased risk of total stroke (HR 1.07, 95% CI 1.02-1.12) and ischemic stroke (HR 1.08, 95% CI 1.03-1.13) per SD (1.04 mmol/L) increase, while no significant association was obtained between TC change and intracerebral hemorrhage (p = 0.659). Conclusions: Increased 2-year TC change is associated with an elevated risk of incident total stroke and ischemic stroke, irrespective of the baseline TC value. Maintaining a sustained ideal level of TC is important for stroke prevention.

Association Between Visit-to-Visit Variability in Low-Density Lipoprotein Cholesterol and Plaque Rupture That Leads to Acute Coronary Syndrome

Background: The effect of intraindividual variability in lipid levels on the onset of acute coronary syndrome (ACS) remains uncertain. We evaluated the relationship between intraindividual variability in lipid levels and culprit lesion morphologies by optical coherence tomography (OCT).

Methods and Results: Seventy-four consecutive patients with ACS whose cholesterol levels were assessed ≥3 times during outpatient visits before the onset of ACS were enrolled in the study; 222 patients without significant stenotic lesions were used as a control group. Based on OCT findings of culprit lesions, ACS patients were categorized into a plaque rupture ACS (PR-ACS) group (n=44) or a non-plaque rupture ACS (NPR-ACS) group (erosion or calcified nodule; n=30). Visit-to-visit variability in lipid levels was evaluated using the corrected variability independent of the mean (cVIM). Patients with ACS had significantly higher low-density lipoprotein cholesterol (LDL-C) levels and cVIM in LDL-C than the control group. The PR-ACS group had significantly higher mean LDL-C levels and greater cVIM in LDL-C than the control group. The PR-ACS group had a significantly higher cVIM than the NPR-ACS group, despite similar mean LDL-C levels. Multivariate analysis revealed that higher cVIM of LDL-C was an independent predictor of PR-ACS (odds ratio 1.06; P=0.018).

Conclusions: In addition to the LDL-C level, greater visit-to-visit variability in LDL-C levels may be associated with the onset of ACS induced by plaque rupture.

HDL-C, longitudinal change and risk of mortality in a Chinese cohort study

BACKGROUND AND AIMS

High-density lipoprotein cholesterol (HDL-C) concentration and variability are both important factors of cardiovascular disease (CVD) and mortality. We aimed to explore the associations of HDL-C and longitudinal change in HDL-C with risk of mortality.

METHODS AND RESULTS

We recruited a total of 69,163 participants aged ≥40 years and had medical examination records of HDL-C during 2010-2014 from the Yinzhou District, Ningbo, China. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression models. We observed a non-linear association of HDL-C with risks of non-accidental and CVD mortality. Compared with the moderate concentration group (1.4-1.6 mmol/L), HDL-C <1 mmol/L was associated with a higher risk of non-accidental mortality (HR: 1.13 (95% CI: 1.01-1.27)) and both HDL-C <1 mmol/L and ≥2 mmol/L were associated with a higher risk of CVD mortality (HRs: 1.23 (95% CI: 1.01-1.50) and 1.37 (95% CI: 1.03-1.82), respectively). Compared with the stable group ([-0.1, +0.1 mmol/L]), a large decrease ([-0.5, -0.3 mmol/L]) and very large decrease (<-0.5 mmol/L) in HDL-C were associated with a higher risk of non-accidental mortality (HRs: 1.40 (95% CI: 1.21-1.63) and 1.78 (95% CI: 1.44-2.20), respectively). Similar results were observed for CVD mortality and cancer mortality.

CONCLUSION

Extremely low or high HDL-C and a large decrease or very large decrease in HDL-C were associated with a higher risk of cause-specific mortality. Monitoring of HDL-C may have utility in identifying individuals at higher risk of mortality.

Glycemic and lipid variability for predicting complications and mortality in diabetes mellitus using machine learning

INTRODUCTION

Recent studies have reported that HbA1c and lipid variability is useful for risk stratification in diabetes mellitus. The present study evaluated the predictive value of the baseline, subsequent mean of at least three measurements and variability of HbA1c and lipids for adverse outcomes.

METHODS

This retrospective cohort study consists of type 1 and type 2 diabetic patients who were prescribed insulin at outpatient clinics of Hong Kong public hospitals, from 1st January to 31st December 2009. Standard deviation (SD) and coefficient of variation were used to measure the variability of HbA1c, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride. The primary outcome is all-cause mortality. Secondary outcomes were diabetes-related complications.

RESULT

The study consists of 25,186 patients (mean age = 63.0, interquartile range [IQR] of age = 15.1 years, male = 50%). HbA1c and lipid value and variability were significant predictors of all-cause mortality. Higher HbA1c and lipid variability measures were associated with increased risks of neurological, ophthalmological and renal complications, as well as incident dementia, osteoporosis, peripheral vascular disease, ischemic heart disease, atrial fibrillation and heart failure (p <  0.05). Significant association was found between hypoglycemic frequency (p <  0.0001), HbA1c (p <  0.0001) and lipid variability against baseline neutrophil-lymphocyte ratio (NLR).

CONCLUSION

Raised variability in HbA1c and lipid parameters are associated with an elevated risk in both diabetic complications and all-cause mortality. The association between hypoglycemic frequency, baseline NLR, and both HbA1c and lipid variability implicate a role for inflammation in mediating adverse outcomes in diabetes, but this should be explored further in future studies.

Associations between 20-year lipid variability throughout young adulthood and midlife cognitive function and brain integrity

BACKGROUND

Little is known about long-term lipid variability in young adulthood in relation to cognitive function and brain integrity in midlife.

METHODS

We studied 3,328 adults from the Coronary Artery Risk Development in Young Adults. We defined low- and high- density lipoprotein (LDL, HDL) variability as the intra-individual standard deviation of lipid measurements over 20 years of young adulthood (1985-2005). Cognitive tests were administered in 2010. Brain scans were performed in 2010 on 714 participants. To facilitate comparison, cognitive tests and brain metrics were z-scored.

RESULTS

Mean age at baseline was 25.4 years. Higher 20-year LDL variability was associated with worse verbal memory in midlife (β=-0.25, 95% CI [-0.42, -0.08]), adjusted for important covariates. Higher 20-year HDL variability was associated with worse processing speed in midlife (β=-0.80, 95% CI [-1.18, -0.41]) and brain integrity, e.g. smaller total brain volume (β=-0.58, 95% CI [-0.82, -0.34]) and worse total brain fractional anisotropy (β=-1.13, 95% CI [-1.87, -0.39]).

CONCLUSIONS

Higher long-term lipid variability in adulthood was associated with worse cognition and brain integrity in midlife, in a relatively young cohort.

Visit-to-visit variability of lipid and cardiovascular events in patients with familial hypercholesterolemia

Background

Visit-to-visit variability in lipid has been suggested as a predictor of major adverse cardiovascular events (MACEs). However, no evidence exists on the prognostic value of lipid variability in patients with familial hypercholesterolemia (FH). This prospective cohort study aimed to investigate whether lipid variability affects future MACEs in patients with FH receiving standard lipid-lowering therapy.

Methods

A total of 254 patients with FH were consecutively enrolled and followed for MACEs. Variability in the triglyceride, total cholesterol, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] were evaluated from 3 months after discharge using the standard deviation (SD), coefficient of variation (CV) and variability independent of the mean (VIM).

Results

During a mean follow-up of 49 months, 22 (8.7%) events occurred. Visit-to-visit variability in Lp(a) was significantly higher in the MACE group compared to the non-MACE group. In the multivariate Cox analysis, only Lp(a)-related parameters were independent predictors for MACEs. The hazard ratios and 95% confidence intervals of each 1-SD increase of SD, CV, and VIM of Lp(a) were 1.42 (1.12-1.80), 1.50 (1.11-2.02) and 1.60 (1.16-2.22), respectively. Kaplan-Meier analysis revealed that patients with higher Lp(a) variability presented lower event-free survival. The results were consistent in various subgroups.

Conclusions

Our study firstly suggested that Lp(a) variability was associated with MACEs in real-world patients with FH, which emphasized the importance of regular lipid monitoring in the patients with high risk.

Variability in Annual Fasting Glucose and the Risk of Peripheral Artery Disease in Patients with Diabetes Mellitus

PURPOSE

High glucose concentrations and swings are associated with endothelial dysfunction. We examined the effects of variability in fasting plasma glucose on peripheral artery disease (PAD) in patients with diabetes mellitus (DM).

PATIENTS AND METHODS

In this screening study for the risk factors of PAD, we retrospectively collected data on the ankle-brachial index (ABI) and the percentage of mean arterial pressure (%MAP) at the ankle between August 01, 2016 and July 31, 2017. We defined low ABI ≤0.90, high %MAP ≥45%, or both as high-risk PAD and others as low-risk PAD. We compared the standard deviation (SD) of the first fasting plasma glucose data available each year after January 01, 2007.

RESULTS

In 2577 patients, a higher SD of annual fasting glucose was observed in those with an ABI ≤0.90 than in patients with an ABI >0.90 (2.6 ± 2.1 vs 2.2 ± 2.3, P = 0.009), and in patients with %MAP ≥45% than in those with %MAP <45% (2.4 ± 2.1 vs 2.2 ± 2.3, P = 0.034). A high-risk PAD was significantly associated with the SD (P = 0.032) but not with the mean (P = 0.338) of annual fasting glucose. The former was an independent risk factor for high-risk PAD (odds ratio = 1.424; 95% CI = 1.118‒1.814; P = 0.004).

CONCLUSION

Variability but not mean of annual fasting plasma glucose was significantly associated with a high risk of PAD in patients with DM.

Greater variability in lipid measurements associated with cardiovascular disease and mortality: A 10-year diabetes cohort study

AIM

To examine the associations between variability in lipids and the risk of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes based on low-density lipoprotein-cholesterol (LDL-C), the total cholesterol (TC) to high-density lipoprotein-cholesterol (HDL-C) ratio and triglycerides (TG).

MATERIALS AND METHODS

A retrospective cohort study included 125 047 primary care patients with type 2 diabetes aged 45-84 years without CVD during 2008-2012. The variability of LDL-C, TC to HDL-C and TG was determined using the standard deviation of variables in a mixed effects model to minimize regression dilution bias. The associations between variability in lipids and CVD and mortality risk were assessed by Cox regression. Subgroup analyses based on patients' baseline characteristics were also conducted.

RESULTS

A total of 19 913 CVD events and 15 329 mortalities were recorded after a median follow-up period of 77.5 months (0.8 million person-years), suggesting a positive linear relationship between variability in lipids and the risk of CVD and mortality. Each unit increase in the variability of LDL-C (mmol/L), the TC to HDL-C ratio and TG (mmol/L) was associated with a 27% (HR: 1.27 [95% CI: 1.20-1.34]), 31% (HR:1.31 [95% CI: 1.25-1.38]) and 9% (HR: 1.09 [95% CI: 1.04-1.15]) increase in the risk of composite endpoint of CVD and mortality, respectively. Age-specific effects were also found when comparing LDL-C variability, with patients aged 45-54 years (HR: 1.70 [95% CI: 1.42-2.02]) exhibiting a 53% increased risk for the composite endpoints than those aged 75-84 years (HR: 1.11 [95% CI: 1.01-1.23]). Similar age effects were observed for both the TC to HDL-C ratio and TG variability. Significant associations remained consistent among most of the subgroups.

CONCLUSIONS

Variability in respective lipids are significant factors in predicting CVD and mortality in primary care patients with type 2 diabetes, with the strongest effects related to LDL-C and the TC to HDL-C ratio and most significant in the younger age group of patients aged 45-54 years. Further study is warranted to confirm these findings.

Variability in blood lipids affects the neutrophil to lymphocyte ratio in patients undergoing elective percutaneous coronary intervention: a retrospective study

Background

Atherosclerosis is associated with chronic inflammation and lipid metabolism. The neutrophil to lymphocyte ratio (NLR) as an indicator of inflammation has been confirmed to be associated with cardiovascular disease prognosis. However, few studies have explored the effects of blood lipid variability on NLR. The aim of this study was to explore the relationship between variability in blood lipid levels and NLR.

Methods

The association between variability in blood lipids and NLR was assessed with both univariate and multivariate linear regression. Multivariate linear regression was also performed for a subgroup analysis.

Results

The variability of high-density lipoprotein cholesterol (HDL-C) (regression coefficients [β] 4.008, standard error (SE) 0.503, P-value< 0.001) and low-density lipoprotein cholesterol (LDL-C) ([β] 0.626, SE 0.164, P-value< 0.001) were risk factors for the NLR value, although baseline LDL-C and HDL-C were not risk factors for NLR values. Variability of HDL-C ([β] 4.328, SE 0.578, P-value< 0.001) and LDL-C ([β] 0.660, SE 0.183, P-value< 0.001) were risk factors for NLR variability. Subgroup analysis demonstrated that the relationship between variability of LDL-C and NLR was consistent with the trend of the total sample for those with diabetes mellitus, controlled blood lipid, statins, atorvastatin. The relationship between the variability of HDL-C and NLR was consistent with the trend of the total sample in all subgroups.

Conclusion

The variability of HDL-C and LDL-C are risk factors for the value and variability of NLR, while the relationship between variability of HDL-C and NLR is more stable than the variability of LDL-C in the subgroup analysis, which provides a new perspective for controlling inflammation in patients undergoing PCI.

Effects of Cardiovascular Risk Factor Variability on Health Outcomes

Innumerable studies have suggested "the lower, the better" for cardiovascular risk factors, such as body weight, lipid profile, blood pressure, and blood glucose, in terms of health outcomes. However, excessively low levels of these parameters cause health problems, as seen in cachexia, hypoglycemia, and hypotension. Body weight fluctuation is related to mortality, diabetes, obesity, cardiovascular disease, and cancer, although contradictory findings have been reported. High lipid variability is associated with increased mortality and elevated risks of cardiovascular disease, diabetes, end-stage renal disease, and dementia. High blood pressure variability is associated with increased mortality, myocardial infarction, hospitalization, and dementia, which may be caused by hypotension. Furthermore, high glucose variability, which can be measured by continuous glucose monitoring systems or self-monitoring of blood glucose levels, is associated with increased mortality, microvascular and macrovascular complications of diabetes, and hypoglycemic events, leading to hospitalization. Variability in metabolic parameters could be affected by medications, such as statins, antihypertensives, and hypoglycemic agents, and changes in lifestyle patterns. However, other mechanisms modify the relationships between biological variability and various health outcomes. In this study, we review recent evidence regarding the role of variability in metabolic parameters and discuss the clinical implications of these findings.

Impact of Mean and Variability of High-Density Lipoprotein-Cholesterol on the Risk of Myocardial Infarction, Stroke, and Mortality in the General Population

Background

A low level of high‐density lipoprotein‐cholesterol (HDL‐C) is a well‐known risk factor for cardiovascular events. Recent studies have also suggested that HDL‐C variability has a predictive role in patients with coronary artery disease. We investigated the combined effect of the mean and variability of HDL‐C on the risk of myocardial infarction (MI), stroke, and mortality in the general population.

Methods and Results

We selected 5 433 098 subjects in the Korean National Health Insurance System cohort who had no history of MI or stroke and who underwent ≥3 health examinations between 2009 and 2013. Visit‐to‐visit HDL‐C variability was calculated using the coefficient of variation, variability independent of the mean and average real variability. The low‐mean and high‐variability groups were defined as the lowest and highest quartiles of HDL‐C mean and variability, respectively. There were 27 605 cases of MI, 31 162 cases of stroke, and 50 959 deaths during the median follow‐up of 5.1±0.6 years. A lower mean or higher variability (coefficient of variation) of HDL‐C was associated with a higher risk of adverse outcomes, and the 2 measures had an additive effect. In the multivariable‐adjusted model, the hazard ratios (95% CIs) of the low‐mean/high‐variability group compared with the high‐mean/low‐variability group were 1.47 (1.41–1.54) for MI, 1.23 (1.18–1.28) for stroke, and 1.41 (1.36–1.45) for all‐cause mortality. Results were consistent when variability was modeled using variability independent of the mean or average real variability, and in various sensitivity and subgroup analyses.

Conclusions

Low mean and high variability of HDL‐C is associated with an increased risk of MI, stroke, and mortality.

Biomarker variability and cardiovascular disease residual risk

PURPOSE OF REVIEW

A number of cohorts and clinical trials have reported observing associations between intraindividual variation of biomarkers and manifestations of cardiovascular disease (CVD).

RECENT FINDINGS

Intraindividual (or 'visit-to-visit') variability of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, and triglyceride have all been found to associate with CVD outcomes, independent of their mean absolute levels, independent of each other, and independent of other traditional risk factors. These findings have been confirmed recently in large cohort studies in different populations, and in post-hoc analyses of clinical trial data. Lipoprotein variability has been associated with myocardial infarction, other arterial disease including cerebrovascular, and with cardiovascular and overall mortality. The association of higher variability of LDL-C with atheroma progression has also been assessed directly using intravascular ultrasound and carotid intima-media thickness. The lipoprotein variability of an individual contributes to their residual risk of CVD, although the mechanism remains unclear.

SUMMARY

There is compelling evidence that lipoprotein variability contributes to residual risk; however, a more standardized approach is required before the risk attributable to variability can be assessed effectively.

Visit-to-visit variability in low-density lipoprotein cholesterol is associated with adverse events in non-obstructive coronary artery disease

OBJECTIVE

A higher visit-to-visit variability in low-density lipoprotein cholesterol (LDL-C) is associated with an increased frequency of cardiovascular events. We investigated the association between the visit-to-visit LDL-C variability and all-cause mortality, myocardial infarction (MI), and coronary revascularization in a population with non-obstructive coronary artery disease (CAD).

METHODS

From this retrospective cohort of individuals who underwent coronary angiography from 2006 to 2010, a total of 2.012 consecutive patients with non-obstructive CAD, who underwent three or more LDL-C determinations during the first 2 years, were identified and followed up for 5 years. The variability in the visit-to-visit LDL-C was measured by standard deviation (SD) and coefficient of variation (CV). The risk of all-cause mortality and composite endpoints, MI, and coronary revascularization were evaluated by a multivariable Cox regression analysis.

RESULTS

During a 5-year follow-up, a total of 99 (4.92%) mortality cases and 154 (7.65%) cases of composite endpoints were observed. The percentage of subjects who experienced mortality or composite endpoints was higher in those with a higher LDL-C-SD or LDL-C-CV level. The association between the LDL-C variability and clinical endpoints was regardless of possible confounding factors.

CONCLUSION

Among the patients with non-obstructive CAD, a higher visit-to-visit LDL-C variability is associated with increasing all-cause mortality or composite endpoints during the long-term follow-up.

Visit-to-Visit Variability of Lipids Measurements and the Risk of Stroke and Stroke Types: A Prospective Cohort Study

BACKGROUND AND PURPOSE

Previous studies suggested increased visit-to-visit variability of total cholesterol (TC) is associated with stroke. This study aimed to investigate the associations of various lipids measurements variability and the risk of stroke and stroke type (ischemic and hemorrhagic stroke).

METHODS

Fifty-one thousand six hundred twenty participants in the Kailuan Study without history of myocardial infarction, stroke, and cancer who underwent three health examinations during 2006 to 2010 were followed for incident stroke. Variability in TC, triglycerides, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) measurements were measured using the coefficient of variation (CV), standard deviation (SD), variability independent of the mean (VIM), and average real variability (ARV).

RESULTS

During a median of 6.04 years of follow-up, 1,189 incident stroke (1,036 ischemic and 160 hemorrhagic stroke) occurred. In the multivariable-adjusted model, the hazard ratio (HR) comparing participants in the highest versus lowest quartile of CV of HDL-C were 1.21 (95% confidence interval [CI], 1.02 to 1.45; P for trend=0.013) for ischemic stroke. The highest quartile of CV of LDL-C was associated with 2.17-fold risk of hemorrhagic stroke (HR, 2.17; 95% CI, 1.25 to 3.75; P for trend=0.002) compared with the lowest quartile. We did not observe any significant association between TC and triglycerides variability with any of stroke. Consistent.

RESULTS

were obtained when calculating variability index using SD, VIM, or ARV.

CONCLUSIONS

These findings suggest the high visit-to-visit HDL-C and LDL-C variability were associated with an increased incidence of ischemic and hemorrhagic stroke, respectively.

Cholesterol variability and the risk of mortality, myocardial infarction, and stroke: a nationwide population-based study

Aims

A high visit-to-visit variability in cholesterol levels has been suggested to be an independent predictor of major adverse cardiovascular events in patients with coronary artery disease (CAD). Because whether this notion applies to general population is not known, we aimed to investigate the associations between total cholesterol (TC) variability and the risk of all-cause mortality, myocardial infarction (MI), and stroke.

Methods and results

We identified 3 656 648 subjects without a history of MI and stroke who underwent ≥3 health examinations from 2002 to 2007 in the Korean National Health Insurance System cohort. Total cholesterol variability was measured using the coefficient of variation (CV), standard deviation (SD), and variability independent of the mean (VIM). There were 84 625 deaths (2.3%), 40 991 cases of MI (1.1%), and 42 861 cases of stroke (1.2%) during the median follow-up of 8.3 years. There was a linear association between higher TC variability and outcome measures. In the multivariable adjusted model, the hazard ratios and 95% confidence intervals comparing the highest vs. lowest quartiles of CV of TC were 1.26 (1.24-1.28) for all-cause mortality, 1.08 (1.05-1.11) for MI, and 1.11 (1.08-1.14) for stroke, which was independent of mean TC levels and the use of lipid-lowering agents. The results were consistent when modelling variability of TC using SD and VIM, and in various sensitivity analyses.

Conclusion

High variability in lipid levels is associated with adverse health-related outcomes. These findings suggest that lipid variability is an important risk factor in the general population.

Low Lipid Levels and High Variability are Associated With the Risk of New-Onset Atrial Fibrillation

Background

While high levels of lipids and lipid variability are established risk factors for atherosclerotic cardiovascular disease, their roles in the development of atrial fibrillation (AF) are unclear, with previous studies suggesting a “cholesterol paradox.”

Methods and Results

A nationwide population‐based cohort of 3 660 385 adults (mean age 43.4 years) from the Korean National Health Insurance Service database, with ≥3 annual lipid measurements from 2009 to 2012 and without a history of AF or prescription of lipid‐lowering medication before 2012, were identified. Total cholesterol, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and triglycerides levels were measured, and lipid variability was calculated using variability independent of the mean. The cohort was divided into quartiles by lipid levels and lipid variability and followed up for incident AF. During a median 5.4 years of follow‐up, AF was newly diagnosed in 27 581 (0.75%). AF development was inversely associated with high lipid levels (for top versus bottom quartile; total cholesterol, HR 0.78, 95% CI 0.76–0.81; low‐density lipoprotein cholesterol, HR 0.81, 95% CI 0.78–0.84; high‐density lipoprotein cholesterol, HR 0.94, 95% CI 0.91–0.98; triglycerides, HR 0.88, 95% CI 0.85–0.92). Meanwhile, AF development was associated with high lipid variability (for top versus bottom quartile; total cholesterol, HR 1.09, 95% CI 1.06–1.13; low‐density lipoprotein cholesterol, HR 1.12, 95% CI 1.08–1.16; high‐density lipoprotein cholesterol, HR 1.08, 95% CI 1.04–1.12; triglycerides, HR 1.05, 95% CI 1.01–1.08). Men showed greater risk reduction with high triglyceride levels and greater risk with high triglyceride variability for incident AF.

Conclusions

Low cholesterol levels and high cholesterol variability were associated with a higher risk of AF development.

HDL-Cholesterol, Its Variability, and the Risk of Diabetes: A Nationwide Population-Based Study

CONTEXT

The bidirectional relationship between low high-density lipoprotein cholesterol (HDL-C) and glucose intolerance is well established. Recent studies suggested an association of lipid variability with various health outcomes.

OBJECTIVE

To investigate the combined effect of HDL-C levels and their variability on the risk of diabetes.

DESIGN

A population-based cohort study.

SETTING AND PARTICIPANTS

In all, 5,114,735 adults without known diabetes in the Korean National Health Insurance System cohort who underwent three or more health examinations from 2009 to 2013 were included. Visit-to-visit HDL-C variability was calculated using variability independent of the mean (VIM) and the coefficient of variation (CV). Low mean and high variability groups were defined as the lowest and highest quartiles of HDL-C mean and variability, respectively.

MAIN OUTCOME MEASURES

Newly developed diabetes.

RESULTS

There were 122,192 cases (2.4%) of incident diabetes during the median follow-up of 5.1 years. Lower mean or higher variability of HDL-C was associated with higher risk of diabetes in a stepwise manner, and an additive effect of the two measures was noted. In the multivariable-adjusted model, the hazard ratios and 95% CIs for incident diabetes were 1.20 (1.18 to 1.22) in the high mean/high VIM group, 1.35 (1.33 to 1.37) in the low mean/low VIM group, and 1.40 (1.38 to 1.42) in the low mean/high VIM group compared with the high mean/low VIM group. Similar results were observed when modeling the variability using CV and in various subgroup analyses.

CONCLUSIONS

Low mean and high variability in HDL-C were independent predictors of diabetes with an additive effect. Both elevating and stabilizing HDL-C may be important goals for reducing diabetes risk.

Intra-individual variability of total cholesterol is associated with cardiovascular disease mortality: A cohort study

BACKGROUND AND AIMS

The relationship between serum total cholesterol (TC) and mortality remains inconsistent. Additionally, intra-individual variability of cholesterol has been of increasing interest as a new indicator for health outcomes. We aimed to examine the association between TC and its variability and risk of mortality.

METHODS AND RESULTS

We performed a retrospective cohort study with 122,645 individuals aged over 40 years in Ningbo, China. The intra-individual variability was calculated using four metrics including standard deviation, coefficient variation, variation independent of mean and average successive variability. Hazard ratios and 95% confidence intervals were estimated for the associations of baseline and variability in TC with risk of mortality by Cox proportional hazards regression models. During 591,585.3 person-years of follow-up, 4563 deaths (including 1365 from cardiovascular disease, 788 from stroke and 1514 from cancer) occurred. A U-shaped association was observed for baseline TC level and risk of total, cardiovascular and cancer mortality, with lowest mortality at 5.46 mmol/L, 5.04 mmol/L and 5.51 mmol/L, respectively. As compared with subjects with TC variability in the lowest quartile, individuals in the highest quartile had 21% higher risk of all-cause mortality (HR = 1.21, 95% CI: 1.05 to 1.40), and 41% higher risk of CVD mortality (HR = 1.41, 95%CI: 1.10 to 1.81).

CONCLUSION

Both too low and too high baseline TC level were associated with higher risk of total, cardiovascular disease and cancer mortality. Variability of TC could be a risk factor of total and CVD mortality, independent of mean TC level. Future studies are needed to confirm these findings.

Within subject variability of HDL-cholesterol in HIV-infected patients

Background and objective: Within-subject variability of cardiovascular risk factors may influence the development of cardiovascular disease. We aimed to improve knowledge on HDL-cholesterol variability and its clinical significance in HIV-infected patients, a population at high risk of cardiovascular disease.Methods: This was a cohort study to quantify the variability of HDL-cholesterol between two consecutive visits and to determine factors associated with such variability, in a group of HIV-infected patients.Results: A total of 307 patients were included, mean ± standard deviation of their age was 45.1 ± 8.5 years, and 225 of them (73.3%) were male. The absolute difference (after squaring and root squaring) of serum HDL-cholesterol level between the first and the second visit was 12.1 ± 9.2 mg/dL. In 65 patients (21.2%) the absolute value of the difference between both serum HDL-cholesterol level results were 20 mg/dL or higher. In a multivariable analysis the number of cigarettes smoked per day showed a significant, negative, correlation with the absolute difference in serum HDL-cholesterol level between the two visits (P = 0,009).Conclusions: Within-subject variability of HDL-cholesterol was substantial among our HIV-infected patients. Smoking was inversely correlated with such variability.

Variabilities in Childhood Cardiovascular Risk Factors and Incident Diabetes in Adulthood: The Bogalusa Heart Study

OBJECTIVE

Although emerging evidence indicates that increased variability in cardiovascular risk factors (CVRFs) among populations at midlife or later is a reliable predictor of adverse health outcomes, it is unknown whether intraindividual CVRF variability during childhood or adolescence is an independent predictor of later-life diabetes. We aimed to examine the association of CVRF variability during childhood with diabetes in later life.

RESEARCH DESIGN AND METHODS

We included 1,718 participants who participated in the Bogalusa Heart Study and had measures at least four times during childhood (aged 4-19 years). The mean follow-up period was 20.5 years. Intraindividual CVRF variabilities during childhood were calculated using SD, coefficient of variation, deviation from age-predicted values, and residual SD based upon four to eight serial measurements in childhood.

RESULTS

Increased variability in BMI or HDL cholesterol (HDL-C) during childhood, irrespective of the indices used, was significantly positively associated with later-life diabetes risk independent of their respective mean levels in childhood and other possible confounding factors. In combined analysis, the magnitude of the association with diabetes risk was similar for high childhood BMI variability and high childhood HDL-C variability. After adjustments for potential confounding variables, other CVRF variabilities including systolic/diastolic blood pressure, total cholesterol, triglycerides, and LDL cholesterol were not significantly associated with diabetes.

CONCLUSIONS

Increased BMI and HDL-C variabilities during childhood were significant risk factors for the development of diabetes independently of diverse risk factors, which may offer new insights into the childhood origin of adult-onset diabetes.

Visit-to-visit variability of metabolic parameters and risk of heart failure: A nationwide population-based study

BACKGROUND

This study examined the effects of variability of four metabolic parameters, namely systolic blood pressure (BP), body mass index (BMI), fasting blood glucose (FBG), and total cholesterol level (TC) on the risk of HF. The effects of metabolic parameter variability on the risk of heart failure (HF) remain unclear.

METHODS

We studied individuals aged ≥40 years who had undergone ≥3 health check-ups under the Korean National Health Insurance Corporation during 2009 and 2012, and those who did not have hypertension, diabetes, or dyslipidemia. BP, BMI, FBG, and TC were measured at every visit. We defined the variability of each parameter using the variability independent of the mean (VIM) method. VIMs were categorized into four groups according to quartiles. The metabolic variability (MV) score for each subject was defined as the number of VIMs in the highest quartile.

RESULTS

Among the 3,820,191 subjects, 17,253 (0.45%) had incident HF during a mean 5.3 ± 1.1 years of follow-up. High variability of each parameter was associated with increased HF risk, which increased according to the MV score. After multivariable adjustment, compared to subjects with MV score = 0, subjects with MV score = 1-4 had an increased risk of HF (adjusted HR [95% CI], 1.15 [1.10-1.19] for MV score = 1, 1.33 [1.28-1.39] for MV score = 2, 1.48 [1.40-1.57] for MV score = 3, 1.74 [1.55-1.96] for MV score = 4 [p-for-trend ≪0.0001]).

CONCLUSIONS

High variability of BP, BMI, FBG, and TC was synergistically associated with a higher incidence of new-onset HF.

Variability in Total Cholesterol Concentration Is Associated With the Risk of Dementia: A Nationwide Population-Based Cohort Study

Introduction: Although total cholesterol (TC) variability is suggested as a risk factor for cardiovascular and cerebrovascular disease, there is no previous study to evaluate the association between TC variability and the development of dementia. Methods: Using the Korean National Health Insurance Service-Health Screening Cohort (NHIS-HEALS), the main outcomes were newly diagnosed all-cause dementia, Alzheimer's disease (AD), or vascular dementia (VaD) between January 1, 2008, and December 31, 2015. Visit-to-visit TC variability was measured as variability independent of the mean (TC-VIM), coefficient variance (TC-CV), and standard deviation (TC-SD). Results: In a total of 131,965 Koreans, there were 3,722 all-cause dementia (2.82%), 2,776 AD (2.10%), and 488 VaD (0.37%) during the median follow-up of 8.4 years. Kaplan-Meier curves showed increased cumulative incidences for all in the group of the highest quartiles of TC variability compared to the others. Regression using the Fine and Gray hazards model showed a steadily increasing risk of all-cause dementia with higher quartiles of TC variability. After adjusting for confounders including mean TC level and comparing the highest and lowest TC-VIM quartiles, the hazard ratios (HRs) for all-cause dementia and AD were 1.15 [95% confidence interval (CI) = 1.05-1.27; P = 0.003] and 1.12 (95% CI = 1.00-1.25; P = 0.040), respectively. The incidence of VaD was not significantly higher in the higher-quartile groups compared to that in the lowest-quartile group in TC-VIM variability (HR 1.22; 95% CI = 0.95-1.59; P = 0.122). These associations were consistent with TC variability defined by TC-CV or TC-SD. Conclusions: For the first time, we have demonstrated that a higher visit-to-visit variability in TC independent of mean TC is associated with an increased risk of all-cause dementia and AD in the general population.

Analysis of serum changes in response to a high fat high cholesterol diet challenge reveals metabolic biomarkers of atherosclerosis

Atherosclerotic plaques are characterized by an accumulation of macrophages, lipids, smooth muscle cells, and fibroblasts, and, in advanced stages, necrotic debris within the arterial walls. Dietary habits such as high fat and high cholesterol (HFHC) consumption are known risk factors for atherosclerosis. However, the key metabolic contributors to diet-induced atherosclerosis are far from established. Herein, we investigate the role of a 2-year HFHC diet challenge in the metabolic changes of development and progression of atherosclerosis. We used a non-human primate (NHP) model (baboons, n = 60) fed a HFHC diet for two years and compared metabolomic profiles in serum from animals on baseline chow with serum collected after the challenge diet using two-dimensional gas chromatography time-of-flight mass-spectrometry (2D GC-ToF-MS) for untargeted metabolomic analysis, to quantify metabolites that contribute to atherosclerotic lesion formation. Further, clinical biomarkers associated with atherosclerosis, lipoprotein measures, fat indices, and arterial plaque formation (lesions) were quantified. Using two chemical derivatization (i.e., silylation) approaches, we quantified 321 metabolites belonging to 66 different metabolic pathways, which revealed significantly different metabolic profiles of HFHC diet and chow diet fed baboon sera. We found heritability of two important metabolites, lactic acid and asparagine, in the context of diet-induced metabolic changes. In addition, abundance of cholesterol, lactic acid, and asparagine were sex-dependent. Finally, 35 metabolites correlated (R2, 0.068-0.271, P < 0.05) with total lesion burden assessed in three arteries (aortic arch, common iliac artery, and descending aorta) which could serve as potential biomarkers pending further validation. This study demonstrates the feasibility of detecting sex-specific and heritable metabolites in NHPs with diet-induced atherosclerosis using untargeted metabolomics allowing understanding of atherosclerotic disease progression in humans.

Association of Variability in Body Mass Index and Metabolic Health With Cardiometabolic Disease Risk

Background Metabolic syndrome is associated with high risk of cardiovascular disease, although risk may differ according to the specific conditions present and variability in those conditions. Methods and Results We defined obesity (body mass index [BMI] ≥30 kg/m2) and metabolic health (<2 nonobesity National Cholesterol Education Program Adult Treatment Panel III conditions) among 3632 Framingham Heart Study offspring cohort participants (mean age, 50.8 years; 53.8% women) who were followed up from 1987 to 2014. We defined participants whose variance independent of the mean for a metabolic syndrome-associated measure was in the top quintile as being "variable" for that measure. Variable metabolic health was defined as ≥2 variable nonobesity metabolic syndrome components. We investigated the interaction between obesity and metabolic health in their associations with cardiometabolic disease and cardiovascular disease using Cox proportional hazards regression. In addition, we estimated the associations of BMI variability and variable metabolic health with study outcomes within categories of obesity and metabolic health status, respectively. We observed 567 incident obesity (41 439 person-years), 771 incident metabolically unhealthy state (25 765 person-years), 272 incident diabetes mellitus (56 233 person-years), 503 incident hypertension (12 957 person-years), 589 cardiovascular disease (60 300 person-years), and 195 chronic kidney disease (47 370 person-years) events on follow-up. Obesity and being metabolically unhealthy were independently and positively associated with all outcomes. BMI variability, compared with stable BMI, was associated with 163%, 67%, 58%, and 74% higher risks of having obesity, becoming metabolically unhealthy, having diabetes mellitus, and having hypertension, respectively, among nonobese participants. Variable metabolic health, compared with stable metabolic health, was associated with a 28% higher risk of cardiovascular disease, among metabolically healthy participants. Conclusions We did not observe evidence for a positive interaction between obesity and metabolic health status with regard to study outcomes. BMI and metabolic health variability are associated with adverse health outcomes.

Effect of visit-to-visit LDL-, HDL-, and non-HDL-cholesterol variability on mortality and cardiovascular outcomes after percutaneous coronary intervention

BACKGROUND AND AIMS

Visit-to-visit variability in biological measures has been suggested as an independent predictor of cardiovascular disease (CVD). Although low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) are important risk factors of CVD, there are few studies investigating the effect of variability in LDL-C and HDL-C on cardiovascular outcomes. We investigated the association between visit-to-visit variability in LDL-C, HDL-C, and non-HDL-C and major adverse cardiovascular and cerebrovascular events (MACCE) in patients who underwent percutaneous coronary intervention (PCI).

METHODS

Data from 1792 subjects who underwent PCI from January 2004 to December 2009 were analyzed. Visit-to-visit variability was calculated using various indices: standard deviation (SD), coefficient of variation, and corrected variability independent of mean (cVIM). MACCE comprised all-cause death, non-fatal myocardial infarction, and stroke.

RESULTS

During a median follow-up period of 65 months, 114 subjects (6.4%) experienced MACCE: 68 (3.8%) all-cause death; 43 (2.4%) stroke, and 15 (0.8%) non-fatal myocardial infarction. Visit-to-visit variability in LDL-C, HDL-C, and non-HDL-C was significantly higher in the MACCE group compared to the non-MACCE group. In multiple regression analysis, all LDL-C, HDL-C, and non-HDL-C variability parameters were independent predictors for MACCE after adjusting for potential confounding factors. Each 1-SD increase of cVIM in LDL-C, HDL-C, and non-HDL-C increased the risk of MACCE by 34% (HR 1.34 [95% CI, 1.18-1.52]), 50% (HR 1.50 [95% CI 1.32-1.71]), and 37% (HR 1.37 [95% CI, 1.20-1.57]), respectively. These relationships were observed in various subgroups according to age, sex, and diabetes status.

CONCLUSIONS

Visit-to-visit variability in LDL-C, HDL-C, and non-HDL-C is associated with MACCE in subjects with previous PCI.

Incremental Value of Repeated Risk Factor Measurements for Cardiovascular Disease Prediction in Middle-Aged Korean Adults: Results From the NHIS-HEALS (National Health Insurance System-National Health Screening Cohort)

BACKGROUND

Increasing evidence suggests that repeatedly measured cardiovascular disease (CVD) risk factors may have an additive predictive value compared with single measured levels. Thus, we evaluated the incremental predictive value of incorporating periodic health screening data for CVD prediction in a large nationwide cohort with periodic health screening tests.

METHODS AND RESULTS

A total of 467 708 persons aged 40 to 79 years and free from CVD were randomly divided into development (70%) and validation subcohorts (30%). We developed 3 different CVD prediction models: a single measure model using single time point screening data; a longitudinal average model using average risk factor values from periodic screening data; and a longitudinal summary model using average values and the variability of risk factors. The development subcohort included 327 396 persons who had 3.2 health screenings on average and 25 765 cases of CVD over 12 years. The C statistics (95% confidence interval [CI]) for the single measure, longitudinal average, and longitudinal summary models were 0.690 (95% CI, 0.682-0.698), 0.695 (95% CI, 0.687-0.703), and 0.752 (95% CI, 0.744-0.760) in men and 0.732 (95% CI, 0.722-0.742), 0.735 (95% CI, 0.725-0.745), and 0.790 (95% CI, 0.780-0.800) in women, respectively. The net reclassification index from the single measure model to the longitudinal average model was 1.78% in men and 1.33% in women, and the index from the longitudinal average model to the longitudinal summary model was 32.71% in men and 34.98% in women.

CONCLUSIONS

Using averages of repeatedly measured risk factor values modestly improves CVD predictability compared with single measurement values. Incorporating the average and variability information of repeated measurements can lead to great improvements in disease prediction.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02931500.

Visit-to-visit variability of lipid measurements as predictors of cardiovascular events

BACKGROUND

Higher visit-to-visit variability in risk factors such as blood pressure and low-density lipoprotein (LDL)-cholesterol are associated with an increase in cardiovascular (CV) events.

OBJECTIVE

The purpose of this study was to determine whether variability in high-density lipoprotein cholesterol (HDL-C) and triglyceride levels predicted coronary and CV events in a clinical trial population with known coronary disease.

METHODS

We assessed intraindividual variability in fasting high-density lipoprotein (HDL)-cholesterol, triglyceride, and LDL-cholesterol measurements among 9572 patients in the Treating to New Targets trial and correlated the results with coronary events over a median follow-up of 4.9 years.

RESULTS

In the fully adjusted Cox model, 1 standard deviation of average successive variability, defined as the average absolute difference between successive values, was associated with an increased risk of a coronary event for HDL-cholesterol (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.11-1.21, P < .0001), for triglycerides (HR 1.09, 95% CI 1.04-1.15, P = .0005), and for LDL-cholesterol (HR 1.14, 95% CI 1.09-1.19, P < .0001). Similar results were found for the 3 other measures of variability, standard deviation, coefficient of variability, and variability independent of the mean. Similar results were seen for CV events, stroke, and nonfatal myocardial infarction. Higher variability in triglyceride and LDL-cholesterol, but not HDL-cholesterol, was predictive of incident diabetes. The correlation among the variability of the 3 lipid measurements was weak.

CONCLUSION

Visit-to-visit variability in fasting measurements of HDL-cholesterol, triglycerides, and LDL-cholesterol are predictive of coronary events, CV events, and for triglyceride and low-density lipoprotein cholesterol variability, incident diabetes. The mechanisms accounting for these associations remain to be determined.

Greater low-density lipoprotein cholesterol variability is associated with increased progression to dialysis in patients with chronic kidney disease stage 3

Increasing evidence suggests that lipid variability may be a predictor of cardiovascular events. However, few studies have evaluated the association between lipid variability and renal outcomes in patients with moderate-to-advanced chronic kidney disease (CKD). Therefore, the aims of this study were to assess whether lipid variability is associated with progression to dialysis in patients with CKD stage 3–5, and to evaluate the risk factors of lipid variability. This longitudinal study enrolled 725 patients with CKD stage 3–5. Intra-individual lipid variability was defined as the standard deviations (SDs) of lipid levels. The renal end-point was defined as commencing dialysis. During a mean follow-up period of 3.2 years, 208 patients (28.7%) started dialysis. The patients with CKD stage 3 with high low-density lipoprotein (LDL) cholesterol SD (per 1 mg/dL; hazard ratio, 1.035; 95% confidence interval, 1.003 to 1.067; p = 0.003) were associated with an increased risk of progression to dialysis, however this association was not seen in the patients with CKD stage 4 or 5. Furthermore, in the patients with CKD stage 3, a high urine protein-to-creatinine ratio (p < 0.001) and the use of statins (p < 0.001) were significantly associated with an increased LDL-cholesterol SD. Greater LDL-cholesterol variability was associated with an increased risk of progression to dialysis in patients with CKD stage 3, but not in those with CKD stage 4 or 5. These findings support the potential role of aggressive lipid control on clinical outcomes and highlight its importance in patients with CKD stage 3.

High-density Lipoprotein and Low-density Lipoprotein Therapeutic Approaches in Acute Coronary Syndromes

BACKGROUND

Low-density lipoprotein cholesterol (LDL), and especially its oxidized form, renders the atherosclerotic plaque vulnerable to rupture in acute coronary syndromes (ACS). On the other hand, high-density lipoprotein (HDL) is considered an anti-atherogenic molecule. The more recent HDL-targeted drugs may prove to be superior to those used before. Indeed, delipidated HDL and HDL mimetics are efficient in increasing HDL levels, while the apoA-I upregulation with RVX-208 appears to offer a clinical benefit which is beyond the HDL related effects. HDL treatment however has not shown a significant improvement in the outcomes of patients with ACS so far, studies have therefore focused again on LDL. In addition to statins and ezetimibe, novel drugs such as PSCK9 inhibitors and apolipoprotein B inhibitors appear to be both effective and safe for patients with hyperlipidemia.

CONCLUSION

Data suggest these could potentially improve the cardiovascular outcomes of patient with ACS. Yet, there is still research to be done, in order to confirm whether ACS patients would benefit from LDL- or HDL-targeted therapies or a combination of both.

Variability in Total Cholesterol Is Associated With the Risk of End-Stage Renal Disease: A Nationwide Population-Based Study

OBJECTIVE

Recent data suggest that visit-to-visit variability of cholesterol is associated with cardiovascular events. We evaluated the role of lipid variability as a determinant of end-stage renal disease (ESRD).

APPROACH AND RESULTS

Using nationally representative data from the Korean National Health Insurance System, 8 493 277 subjects who were free of ESRD and who underwent ≥3 health examinations during 2005 to 2010 were followed to the end of 2015. Total cholesterol (TC) variability was measured using the coefficient of variation, SD, and the variability independent of the mean. The primary outcome was the development of ESRD, defined as a combination of the relevant disease code and the initiation of renal replacement therapy. There were 11 247 cases of ESRD during a median follow-up of 6.1 years. There was a graded association between a higher TC variability and incident ESRD. In the multivariable adjusted model, the hazard ratios and 95% confidence intervals comparing the highest versus lowest quartiles of coefficient of variation of TC were 2.66 (95% confidence interval, 2.52-2.82). The results were consistent when the variability of TC was modeled using SD and variability independent of the mean and were independent of preexisting chronic kidney disease.

CONCLUSIONS

Increasing TC variability was associated with an increasing incidence of ESRD.