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

Metabolic syndrome parameters' variability and stroke incidence in hypertensive patients: evidence from a functional community cohort

BACKGROUND

Stroke is a common complication of hypertension, but the predictive value of metabolic syndrome parameters' variability on stroke risk in individuals with hypertension remains unclear. Therefore, our objective was to investigate the relationship between metabolic syndrome parameters' variability and the risk of total stroke and its subtypes in hypertensive patients.

METHODS

This prospective cohort study included 17,789 individuals with hypertension from the Kailuan study since 2006. Metabolic syndrome parameters, including waist circumference (WC), fasting blood glucose (FBG), systolic blood pressure (SBP), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG), were collected at three follow-up visits in the 2006, 2008, and 2010 surveys. We assess the variability utilizing the coefficient of variation (CV), standard deviation (SD), average real variation (ARV), and variability independent of the mean (VIM), with CV initially assessed. Participants were categorized based on the number of high-variability metabolic syndrome parameters (0, 1, 2, ≥ 3). Stroke cases were identified by reviewing medical records. The associations between variability in metabolic syndrome parameters and the risk of total stroke and its subtypes were analyzed using Cox proportional hazard regression models.

RESULTS

During a median follow-up of 9.32 years, 1223 cases of stroke were recorded. Participants with ≥ 3 high-variability metabolic syndrome parameters had an increased risk of total stroke (HR: 1.29, 95%CI 1.09-1.52), as well as an increased risk of ischemic stroke (HR: 1.31, 95%CI 1.05-1.63) compared to those without high-variability parameters. The study also examined variability in each metabolic syndrome parameter, and significant associations with an increased risk of total stroke were observed for variability in SBP (HR: 1.24, 95%CI 1.05-1.46) and HDL-C (HR: 1.34, 95%CI 1.09-1.64).

CONCLUSIONS

Long-term fluctuations in metabolic syndrome parameters significantly increase the risk of total stroke, especially ischemic stroke. Maintaining low variability in metabolic syndrome parameters could benefit health, and hypertensive individuals must be regularly monitored.

Association between visit-to-visit lipid variability and risk of ischemic heart disease: a cohort study in China

AIMS

To explore the associations between visit-to-visit lipid variability and risk of ischemic heart disease (IHD) in a population-based cohort in China.

METHODS

We evaluated lipid variability in 30,217 individuals from the Yinzhou Health Information System who had ≥3 recorded lipid measurements during 2010-2014. We used various indicators including standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM), and average real variability (ARV) to quantify the variability in triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Overall, a total of 1305 participants with IHD were identified during the follow-up of 194,421 person-years. Subjects in Q4 had a 21% elevated risk of IHD (HR = 1.21, 95% CI: 1.03-1.41) for LDL-C variability (CV) compared with the reference (Q1). The HRs for Q4 vs Q1 were 1.21 (95% CI: 1.04-1.42) for HDL-C variability, and 1.28 (95% CI: 1.10-1.50) for TC variability. However, no association was observed between triglycerides variability and risk of IHD.

CONCLUSIONS

Higher variability in LDL-C, HDL-C, and TC levels was associated with an elevated risk of IHD, suggesting that lipid variability could be considered as an independent risk factor of IHD.

Effect of 10-year cumulative blood pressure exposure on atherosclerotic cardiovascular disease of different age groups: kailuan cohort study

Background

The level at which cumulative blood pressure (BP) can increase the risk of ASCVD in different age groups remains unclear. This study aimed to investigate the association of 10-year cumulative BP levels with the long-term risk of ASCVD of different age groups.

Methods

Cumulative BP exposure was assessed using the time-weighted average (TWA) BP divided into four BP groups. The participants were also divided into four groups according to their baseline age (<50, 50-59, 60-69, or ≥70 years). The association between TWA BP and the risk of ASCVD was assessed by age group using multivariate Cox models. The China-PAR prediction model was used to assess the ability of TWA BP to predict ASCVD.

Results

In the group aged <50 years, the hazard ratios and 95% confidence intervals for the risk of ASCVD were 2.66 (1.04-6.80), 3.38 (1.54-7.43), and 3.13 (1.36-7.24) for the elevated BP, stage 1 hypertension, and stage 2 hypertension groups, respectively, when compared with the normal BP group. There was a significant difference in the risk of ASCVD between the age groups, with participants aged <50 years having the highest risk, followed by those aged 50-59, 60-69, and ≥70 years.

Conclusions

The risk of ASCVD with high cumulative BP exposure was age-dependent, with a gradual decrease in risk with increasing age.

Lack of association between nonalcoholic fatty liver disease and intracerebral hemorrhage: A community-based cohort study

BACKGROUND

The association between nonalcoholic fatty liver disease (NAFLD) and intracerebral hemorrhage (ICH) remains unclear. This study aimed to investigate whether NAFLD and its severity predict incident ICH.

METHODS

Participants free of other liver diseases, prior stroke, myocardial infarction, cancer, or alcohol abuse in the Kailuan cohort were enrolled in this study. Abdominal ultrasonography was used to diagnose NAFLD and assess its severity. Participants were stratified into different groups including nonfatty liver, mild, moderate and severe NAFLD. Multivariable Cox proportional hazards regression models were used to evaluate the hazard ratios (HRs) and 95% CIs of ICH events in the 11-year follow-up.

RESULTS

A total of 77,461 participants were enrolled in our study. Among them, NAFLD was diagnosed in 23,890 (30.83 %) participants, including 15,581 (20.11 %) with mild NAFLD, 6839 (8.83 %) with moderate NAFLD and 1470 (1.90 %) with severe NAFLD. We documented 692 ICH events during 848,579 person years of follow-up. Patients with more severe NAFLD tended to be older, had higher levels of BMI, higher proportions of hypertension, diabetes and other known risk factors for cerebrovascular disease. However, there was no significant associations between NAFLD, its severity and incident ICH events. Relative to nonfatty liver participants, the HRs for participants with mild NAFLD, moderate and severe NAFLD were 0.98 (95 % CI, 0.80 to 1.20), 1.19 (95 % CI, 0.92 to 1.54) and 1.29 (95 % CI, 0.81 to 2.06), respectively.

CONCLUSIONS

NAFLD and its severity did not appear to be significantly associated with ICH after adjustment for potential risk factors.

China stroke surveillance report 2021

Since 2015, stroke has become the leading cause of death and disability in China, posing a significant threat to the health of its citizens as a major chronic non-communicable disease. According to the China Stroke High-risk Population Screening and Intervention Program, an estimated 17.8 million [95% confidence interval (CI) 17.6-18.0 million] adults in China had experienced a stroke in 2020, with 3.4 million (95% CI 3.3-3.5 million) experiencing their first-ever stroke and another 2.3 million (95% CI 2.2-2.4 million) dying as a result. Additionally, approximately 12.5% (95% CI 12.4-12.5%) of stroke survivors were left disabled, as defined by a modified Rankin Scale score greater than 1, equating to 2.2 million (95% CI 2.1-2.2 million) stroke-related disabilities in 2020. As the population ages and the prevalence of risk factors like diabetes, hypertension, and hyperlipidemia continues to rise and remains poorly controlled, the burden of stroke in China is also increasing. A large national epidemiological survey initiated by the China Hypertension League in 2017 showed that the prevalence of hypertension was 24.7%; the awareness, treatment, and control rates in hypertensive patients were: 60.1%, 42.5%, and 25.4%, respectively. A nationally representative sample of the Chinese mainland population showed that the weighted prevalence of total diabetes diagnosed by the American Diabetes Association criteria was 12.8%, suggesting there are 120 million adults with diabetes in China, and the awareness, treatment, and control rates in diabetic patients were: 43.3%, 49.0%, and 49.4%, respectively. The "Sixth National Health Service Statistical Survey Report in 2018" showed that the proportion of the obese population in China was 37.4%, an increase of 7.2 points from 2013. Data from 1599 hospitals in the Hospital Quality Monitoring System and Bigdata Observatory Platform for Stroke of China (BOSC) showed that a total of 3,418,432 stroke cases [mean age ± standard error (SE) was (65.700 ± 0.006) years, and 59.1% were male] were admitted during 2020. Of those, over 80% (81.9%) were ischemic stroke (IS), 14.9% were intracerebral hemorrhage (ICH) strokes, and 3.1% were subarachnoid hemorrhage (SAH) strokes. The mean ± SE of hospitalization expenditures was Chinese Yuan (CNY) (16,975.6 ± 16.3), ranging from (13,310.1 ± 12.8) in IS to (81,369.8 ± 260.7) in SAH, and out-of-pocket expenses were (5788.9 ± 8.6), ranging from (4449.0 ± 6.6) in IS to (30,778.2 ± 156.8) in SAH. It was estimated that the medical cost of hospitalization for stroke in 2020 was CNY 58.0 billion, of which the patient pays approximately CNY 19.8 billion. In-hospital death/discharge against medical advice rate was 9.2% (95% CI 9.2-9.2%), ranging from 6.4% (95% CI 6.4-6.5%) for IS to 21.8% for ICH (95% CI 21.8-21.9%). From 2019 to 2020, the information about 188,648 patients with acute IS receiving intravenous thrombolytic therapy (IVT), 49,845 patients receiving mechanical thrombectomy (MT), and 14,087 patients receiving bridging (IVT + MT) were collected through BOSC. The incidence of intracranial hemorrhage during treatment was 3.2% (95% CI 3.2-3.3%), 7.7% (95% CI 7.5-8.0%), and 12.9% (95% CI 12.3-13.4%), respectively. And in-hospital death/discharge against medical advice rate was 8.9% (95% CI 8.8-9.0%), 16.5% (95% CI 16.2-16.9%), and 16.8% (95% CI 16.2-17.4%), respectively. A prospective nationwide hospital-based study was conducted at 231 stroke base hospitals (Level III) from 31 provinces in China through BOSC from January 2019 to December 2020 and 136,282 stroke patients were included and finished 12-month follow-up. Of those, over 86.9% were IS, 10.8% were ICH strokes, and 2.3% were SAH strokes. The disability rate [% (95% CI)] in survivors of stroke at 3-month and 12-month was 14.8% (95% CI 14.6-15.0%) and 14.0% (95% CI 13.8-14.2%), respectively. The mortality rate [% (95% CI)] of stroke at 3-month and 12-month was 4.2% (95% CI 4.1-4.3%) and 8.5% (95% CI 8.4-8.6%), respectively. The recurrence rate [% (95% CI)] of stroke at 3-month and 12-month was 3.6% (95% CI 3.5-3.7%) and 5.6% (95% CI 5.4-5.7%), respectively. The Healthy China 2030 Stroke Action Plan was launched as part of this review, and the above data provide valuable guidelines for future stroke prevention and treatment efforts in China.

Serum uric acid variation and the risk of cardiovascular disease: A prospective cohort study

BACKGROUND

The association of serum uric acid (SUA) with cardiovascular disease (CVD) is inconsistent and limited by a single measurement of SUA. This study aimed to investigate the association of SUA variation, considering its magnitude and direction, with the risk of CVD.

METHODS

This study included 41,578 participants with four biennial measurements of SUA during 2006-2012 from the Kailuan study. SUA variation was measured using the coefficient of variation (primary index), standard deviation, average real variability, and variability independent of mean, and the direction of variation was also assessed. Multivariate-adjusted Cox regressions were used to assess the associations, and Bayesian network was utilized to find the most important pathway from SUA variation to CVD.

RESULTS

During a median follow-up of 6.74 (interquartile range: 6.45-7.03) years, we identified 1,852 (4.45%) cases of incident CVD. A large SUA variation (top vs. bottom tertiles) was associated with a higher risk of CVD (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.11-1.40), especially in older adults than that in young adults (Pint=0.0137). The higher risk of CVD was observed with both large rises (HR, 1.24; 95% CI, 1.10-1.39) and falls (HR, 1.19; 95% CI, 1.03-1.38) in SUA variation. The hazardous effect of SUA variation on CVD was mainly induced by excessive inflammation and elevated blood pressure. Similar results were observed for CVD subtypes.

CONCLUSIONS

Elevated SUA variation was associated with a higher risk of CVD, irrespective of the direction of SUA variation, and inflammation played an important role in the pathway.

Association of Multitrajectories of Lipid Indices With Premature Cardiovascular Disease: A Cohort Study

Background The multitrajectory model can identify joint longitudinal patterns of different lipids simultaneously, which might help better understand the heterogeneous risk of premature cardiovascular disease (CVD) and facilitate targeted prevention programs. This study aimed to investigate the associations between multitrajectories of lipids with premature CVD. Methods and Results The study enrolled 78 526 participants from the Kailuan study, a prospective cohort study in Tangshan, China. Five distinct multitrajectories of triglyceride, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol over 6-year exposure were identified on the basis of Nagin's criteria, using group-based multitrajectory modeling. During a median follow-up of 6.75 years (507 645.94 person-years), 665 (0.85%) premature CVDs occurred. After adjustment for confounders, the highest risk of premature CVD was observed in group 4 (the highest and increasing triglyceride, optimal and decreasing LDL-C, low and decreasing high-density lipoprotein cholesterol) (hazard ratio [HR], 2.13 [95% CI, 1.36-3.32]), followed by group 5 (high and decreasing triglyceride, optimal and increasing LDL-C, low and decreasing high-density lipoprotein cholesterol) (HR, 2.07 [95% CI, 1.45-2.98]), and group 3 (optimal and increasing triglyceride, borderline high and increasing LDL-C, optimal and decreasing high-density lipoprotein cholesterol) (HR, 1.90 [95% CI, 1.32-2.73]). Conclusions Our results showed that the residual risk of premature CVD caused by increasing triglyceride levels remained high despite the fact that LDL-C levels were optimal or declining over time. These findings emphasized the importance of assessing the joint longitudinal patterns of lipids and undertaking potential interventions on triglyceride lowering to reduce the residual risk of premature CVD, even among individuals with optimal LDL-C levels.

Total Cholesterol Variability and the Risk of Osteoporotic Fractures: A Nationwide Population-Based Cohort Study

Several risk factors for osteoporotic fractures have been identified but reports of the association of lipid parameters with the occurrence of osteoporotic fractures have been limited. We aimed to examine whether serum total cholesterol (TC) variability is associated with osteoporotic fractures. The study included 3,00,326 subjects who had undergone three or more health examinations between 2003 and 2008. The primary endpoint was the incidence of osteoporotic fractures, including vertebral, hip, distal radius, and humerus fractures. TC variability was evaluated based on the following three parameters: coefficient of variation (CV), standard deviation (SD), and variability independent of the mean (VIM). A total of 29,044 osteoporotic fracture events (9.67%) were identified during a median of 11.6 years of follow-up. The risk of osteoporotic fractures in the highest quartile was significantly higher compared with the lowest quartile according to the three indices of TC variability with adjusted hazard ratios (HR) and 95% confidence intervals (CI) as follows: CV (HR 1.11, 95% CI [1.08–1.15]), SD (HR 1.07, 95% CI [1.04–1.11]) and VIM (HR 1.07, 95% CI [1.04–1.11]). The Kaplan–Meier curves showed a significantly positive relationship between the higher quartile of TC variability and overall osteoporotic fractures. The association remained significant in subgroup analyses of vertebral and hip fractures, regardless of the indices of TC variability. Our study showed that visit-to-visit TC variability was found to be associated with osteoporotic fracture risk. Maintaining TC levels stable may help attenuate the osteoporotic fracture risk in the future.

Development and validation of risk prediction models for stroke and mortality among patients with type 2 diabetes in northern China

BACKGROUND

Stroke is one of the leading causes of disability and mortality in patients with type 2 diabetes mellitus (T2DM). Risk models have been developed for predicting stroke and stroke-associated mortality among patients with T2DM. Here, we evaluated risk factors of stroke for individualized prevention measures in patients with T2DM in northern China.

METHODS

In the community-based Tianjin Chronic Disease Cohort study, 58,042 patients were enrolled between January 2014 and December 2019. We used multiple imputation (MI) to impute missing variables and univariate and multivariate Cox's proportional hazard regression to screen risk factors of stroke. Furthermore, we established and validated first-ever prediction models for stroke (Model 1 and Model 2) and death from stroke (Model 3) and evaluated their performance.

RESULTS

In the derivation and validation groups, the area under the curves (AUCs) of Models 1-3 was better at 5 years than at 8 years. The Harrell's C-index for all models was above 0.7. All models had good calibration, discrimination, and clinical net benefit. Sensitivity analysis using the MI dataset indicated that all models had good and stable prediction performance.

CONCLUSION

In this study, we developed and validated first-ever risk prediction models for stroke and death from stroke in patients with T2DM, with good discrimination and calibration observed in all models. Based on lifestyle, demographic characteristics, and laboratory examination, these models could provide multidimensional management and individualized risk assessment. However, the models developed here may only be applicable to Han Chinese.

Hypertriglyceridemia and Atherosclerotic Carotid Artery Stenosis

Both fasting and non-fasting hypertriglyceridemia have emerged as residual risk factors for atherosclerotic disease. However, it is unclear whether hypertriglyceridemia increases the risks of the progression of carotid artery stenosis. Statins are well known to prevent carotid plaque progression and improve carotid plaque instability. In addition, statin therapy is also known to reduce cerebrovascular events in patients with carotid artery stenosis and to improve clinical outcomes in patients undergoing revascularization procedures. On the other hand, there have been no randomized controlled trials showing that the combination of non-statin lipid-lowering drugs with statins has additional beneficial effects over statin monotherapy to prevent cerebrovascular events and stenosis progression in patients with carotid artery stenosis. In this article, the authors demonstrate the mechanisms of atherosclerosis formation associated with hypertriglyceridemia and the potential role of lipid-lowering drugs on carotid artery stenosis. The authors also review the articles reporting the relationships between hypertriglyceridemia and carotid artery stenosis.

Hypertriglyceridemia is associated with stroke after non-cardiac, non-neurological surgery in the older patients: A nested case-control study

Introduction

Geriatric postoperative stroke is a rare but serious complication after surgery. The association between hypertriglyceridemia and postoperative stroke remains controversial, especially in older patients undergoing non-cardiac, non-neurological surgery. The study aims to address this clinical dilemma.

Materials and methods

We conducted a nested case-control study among 9601 aged patients undergoing non-cardiac non-neurological surgery from October 2015 to 2021. A total of 22 positive cases were matched for the surgical type and time, to 88 control patients by a ratio of 1:4. The effect of hypertriglyceridemia on the occurrence of postoperative stroke within 30 days after surgery was estimated using conditional logistic regression analysis by adjusting to various potential confounders.

Results

A total of 22 cases developed ischemia stroke after surgery, and compared with the non-stroke group, they had more postoperative ICU admission, longer postoperative hospitalization and higher total cost (all p &lt; 0.05), and more patients were presenting with preoperative hypertriglyceridemia [8 (36.4%) vs. 15 (17.0%), p = 0.045]. There was a significant association between hypertriglyceridemia and postoperative stroke, with adjusted odds ratios of 6.618 (95% CI 1.286, 34.064) (p = 0.024). The above results remained robust in the sensitivity analyses.

Conclusion

Among older patients undergoing non-cardiac and non-neurological surgery, hypertriglyceridemia was associated with significant increased risk of postoperative stroke.

Nonalcoholic fatty liver disease and risk of intracerebral hemorrhage

BACKGROUND AND AIMS

This study aimed to investigate the association between the steatosis severity of nonalcoholic fatty liver disease (NAFLD) and future intracerebral hemorrhage (ICH) risk.

METHODS AND RESULTS

We used data from the Kailuan study. Participants without a history of stroke, myocardial infarction, cancer, other liver diseases or alcohol abuse were enrolled. NAFLD and the severity of liver steatosis were assessed by abdominal ultrasonography. We stratified the participants into different groups according to the severity changes in liver steatosis status across the first 4-year follow-up period. The outcome was the first occurrence of ICH during the next 6-year follow-up period. Hazard ratios (HRs) and 95% CI of ICH were estimated using Cox models adjusted for potential risk factors. A total of 49,906 participants were enrolled in this study. During a median of 6.79 years of follow-up, 193 incident ICH cases were identified. Compared with persistent nonfatty liver participants, the hazard ratios (HRs) for participants with persistent mild steatosis, persistent moderate steatosis, persistent severe steatosis, alleviating steatosis, and aggravating steatosis were 1.28 (95% CI, 0.75-2.18), 2.33 (95% CI, 1.24-4.38), 1.63 (95% CI, 0.22-12.11), 1.41 (95% CI, 0.91-2.18), and 1.37 (95% CI, 0.94-2.00), respectively, in the fully adjusted model.

CONCLUSIONS

NAFLD with persistent moderate steatosis was significantly related to an increased risk of future ICH, independent of other conventional risk factors.

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.

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.

Triglyceride-glucose index variability and incident cardiovascular disease: a prospective cohort study

Background

Recent studies have suggested that triglyceride-glucose (TyG) index is an independent predictor of cardiovascular disease (CVD). However, the impact of long-term visit-to-visit variability in TyG index on the risk of CVD is not known. We aimed to investigate the longitudinal association between baseline and mean TyG index as well as TyG index variability and incident CVD in a Chinese population.

Methods

We included 49,579 participants without previous history of CVD in the Kailuan study who underwent three health examinations (2006, 2008, and 2010) and were followed up for clinical events until 2019. TyG index was calculated as Ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. We measured TyG index variability as the SD of the residuals obtained from a linear regression on the three TyG index measurements for each individual. Multivariate-adjusted Cox models were used to estimate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) with incident CVD.

Results

During a median follow-up time of 9.0 years, 2404 developed CVD. The highest tertile (T3) of baseline and mean TyG index were each associated with higher CVD incidence as compared with the lowest tertile (T1): aHR, 1.25; 95% CI 1.11–1.42; and aHR 1.40; 95% CI 1.24–1.58, respectively. Tertile 3 of TyG index variability was associated with increased CVD incidence compared to T1 group (aHR, 1.12; 95% CI 1.01–1.24). Similar findings were observed in a series of sensitivity analyses.

Conclusion

Higher TyG index level and greater TyGindex variability were each independently associated with a higher incidence of CVD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01541-5.

Remnant Cholesterol Variability and Incident Ischemic Stroke in the General Population

BACKGROUND

Studies have demonstrated that remnant cholesterol is correlated with the risk of ischemic stroke. However, it is unknown whether visit-to-visit variability in remnant cholesterol concentration affects ischemic stroke. We sought to examine the role of remnant cholesterol variability in the subsequent development of ischemic stroke in the general population.

METHODS

We performed a post hoc analysis including eligible participants from the Kailuan Study cohort who underwent 3 health examinations and were free of atrial fibrillation, myocardial infarction, stroke, cancer, or known lipid-medication use from 2006 to 2010. Participants were followed up until the end of 2017. Variability was quantified as variability independent of the mean, average real variability, and SD. Multivariate analysis was performed using the Fine and Gray competing risk model to estimate subhazard ratios assuming death as a competing risk.

RESULTS

The final study cohort comprised 38 556 participants. After a median follow-up of 7.0 years, 1058 individuals were newly diagnosed with ischemic stroke. After adjusting for age (time scale), sex, smoking status, alcohol consumption, physical activity, hypertension, diabetes, family history of cardiovascular disease, body mass index, estimated glomerular filtration rate, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and mean remnant cholesterol, the highest quartile (quartile 4) of variability independent of the mean of remnant cholesterol was associated with an increased ischemic stroke risk compared with the lowest quartile (quartile 1), (subhazard ratio, 1.27 [95% CI, 1.06-1.53]). For each 1-SD increase in variability independent of the mean of remnant cholesterol, the risk increased by 9% (subhazard ratio, 1.09 [95% CI, 1.03-1.16]). The association was also significant using average real variability and SD as indices of variability.

CONCLUSIONS

Greater remnant cholesterol variability was associated with a higher risk of ischemic stroke in the general population.

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.

Hypertriglyceridemia: A Neglected Risk Factor for Ischemic Stroke?

Hypertriglyceridemia is caused by defects in triglyceride metabolism and generally manifests as abnormally high plasma triglyceride levels. Although the role of hypertriglyceridemia may not draw as much attention as that of plasma cholesterol in stroke, plasma triglycerides, especially nonfasting triglycerides, are thought to be correlated with the risk of ischemic stroke. Hypertriglyceridemia may increase the risk of ischemic stroke by promoting atherosclerosis and thrombosis and increasing blood viscosity. Moreover, hypertriglyceridemia may have some protective effects in patients who have already suffered a stroke via unclear mechanisms. Therefore, further studies are needed to elucidate the role of hypertriglyceridemia in the development and prognosis of ischemic stroke.

The Association of Postprandial Triglyceride Variability with Renal Dysfunction and Microalbuminuria in Patients with Type 2 Diabetic Mellitus: A Retrospective and Observational Study

OBJECTIVE

We examined whether or not day-to-day variations in lipid profiles, especially triglyceride (TG) variability, were associated with the exacerbation of diabetic kidney disease.

METHODS

We conducted a retrospective and observational study. First, 527 patients with type 2 diabetes mellitus (DM) who had had their estimated glomerular filtration rate (eGFR) checked every 6 months since 2012 for over 5 years were registered. Variability in postprandial TG was determined using the standard deviation (SD), SD adjusted (Adj-SD) for the number of measurements, and maximum minus minimum difference (MMD) during the first three years of follow-up. The endpoint was a ≥40% decline from baseline in the eGFR, initiation of dialysis or death. Next, 181 patients who had no micro- or macroalbuminuria in February 2013 were selected from among the 527 patients for an analysis. The endpoint was the incidence of microalbuminuria, initiation of dialysis, or death.

RESULTS

Among the 527 participants, 110 reached a ≥40% decline from baseline in the eGFR or death. The renal survival was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p = 0.0073, 0.0059, and 0.0195, respectively). A lower SD, lower Adj-SD, and lower MMD were significantly associated with the renal survival in the adjusted model (hazard ratio, 1.62, 1.66, 1.59; 95% confidence intervals, 1.05-2.53, 1.08-2.58, 1.04-2.47, respectively). Next, among 181 participants, 108 developed microalbuminuria or death. The nonincidence of microalbuminuria was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p = 0.0241, 0.0352, and 0.0474, respectively).

CONCLUSIONS

Postprandial TG variability is a novel risk factor for eGFR decline and the incidence of microalbuminuria in patients with type 2 DM.

Sex-specific association of BMI change with stroke in middle-aged and older adults with type 2 diabetes

BACKGROUND AND AIMS

We aimed to evaluate the association between BMI change and stroke in middle-aged and older adults with type 2 diabetes and identify sex differences.

METHODS AND RESULTS

The China Health and Retirement Longitudinal Study is an ongoing national population-based cohort study. Participants aged 45 or above with type 2 diabetes were enrolled and followed for stroke incidence. BMI change was defined as BMI at 2013-BMI at 2011. Of 1774 participants (mean [SD] age in 2011, 60.23 [8.88] years), 795 (44.8 %) were men. A total of 112 incident stroke cases were confirmed up to 2018. The incidence rate of stroke was similar between men and women (6.79 % vs 5.92 %, P = 0.516). BMI increase was independently associated with an increased stroke risk (adjusted odds ratio, 1.15; 95 % CI, 1.05-1.31) in men, while this positive association was not significant in women (adjusted odds ratio, 1.12; 95 % CI, 0.98-1.29). In addition, the positive dose-response relationship between BMI increase and stroke was observed only in men.

CONCLUSION

Among middle-aged and older adults with type 2 diabetes, there is a sex-specific association of BMI change with stroke. An increase in BMI could result in a higher risk of incident stroke in men.

Visit-to-visit variability in the measurements of metabolic syndrome components and the risk of all-cause mortality, cardiovascular disease, and arterial stiffness

BACKGROUND AND AIMS

The risk of adverse health conditions varied according to the number of metabolic syndrome components. We aimed to evaluate the risk of mortality and incident cardiovascular events according to the number of components with high variability.

METHODS AND RESULTS

A total of 43,737 Kailuan Study participants with ≥3 examinations of waist circumference, fasting blood glucose, systolic blood pressure, triglyceride, and high-density lipoprotein during 2006-2013 were included in the present study. Visit-to-visit variability in each parameter was defined by the intraindividual standard deviation across visits. High variability was defined as the highest quartile of variability. Participants were classified numerically according to the number of high-variability components (e.g., a score of 0 indicated no high-variability component). There were 1551 deaths during a median follow-up of 5.9 years, and 950 incident cardiovascular disease (CVD) cases during a median follow-up of 4.9 years. In the multivariable adjusted model, compared with participants with low variability for all components, participants with ≥3 high-variability components had significantly higher risks for all-cause mortality (hazards ratio [HR], 1.61; 95 % confidence interval [CI], 1.35-1.91) and incident CVD event (HR, 1.45; 95 % CI, 1.16-1.82). Additionally, participants with ≥3 high-variability components had increased odds of arterial stiffness, as measured by brachia-ankle pulse wave velocity (odds ratio [OR], 1.39; 95 % CI, 1.19-1.63).

CONCLUSIONS

Our findings suggest that participants with at least three metabolic parameters with high variability experienced increased risk of CVD and all-cause mortality.

The association of blood lipid parameters variability with ischemic stroke in hypertensive patients

BACKGROUND AND AIMS

The relationship between lipid variability and stroke among patients with hypertension were inconclusive. We aimed to investigate the association of lipid variability with ischemic stroke in hypertensive patients.

METHODS AND RESULTS

This retrospective cohort study included 4995 individuals with hypertension between 2013 and 2015, and recorded their status of ischemic stroke until the end of 2018. The variability in total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured using the standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM) and average absolute difference between successive values (ASV). Multivariate Cox proportional hazards models with hazard ratios (HRs) and 95% confidence interval (CI) were performed. There were 110 cases of ischemic stroke during a median follow up of 4.2 years. The multivariable adjusted HRs and 95% CIs comparing the highest versus the lowest quartiles of SD of TC, LDL-C, HDL-C and TG were 4.429 (95% CI: 2.292, 8.560), 2.140 (95% CI: 1.264, 3.621), 1.368 (95% CI: 0.793, 2.359) and 1.421 (95% CI: 0.800, 2.525), respectively. High variability in TC and LDL-C were associated with a higher risk for ischemic stroke. Similarly, the results were consistent when calculating variability of TC and LDL-C using CV, ASV and VIM, and in various subgroup analyses.

CONCLUSION

Higher variability of TC and LDL-C associated with the risk of ischemic stroke among hypertensive patients. These findings suggest reducing variability of lipid parameters may decrease adverse outcomes.

Visit-to-visit variability of serum uric acid measurements and the risk of all-cause mortality in the general population

Background

Evidence on longitudinal variability of serum uric acid (SUA) and risk of all-cause mortality in the general population is limited, as many prior studies focused on a single measurement of SUA.

Methods

A total of 53,956 participants in the Kailuan study who underwent three health examinations during 2006 to 2010 were enrolled. Variability of SUA was measured using the coefficient of variation (primary index), standard deviation, average real variability, and variability independent of the mean. Cox proportional hazard regressions were used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for the association of variability of SUA with subsequent risk of all-cause mortality, considering its magnitude and the direction and across different baseline SUA categories.

Results

Over a median follow-up of 7.04 years, 2728 participants died. The highest variability of SUA was associated with an increased risk of all-cause mortality, the HR was 1.33 (95% CI, 1.20–1.49) compared with the lowest variability. In this group, both a large fall (HR, 1.28; 95% CI, 1.14–1.44) and rise (HR, 1.18; 95% 1.05–1.32) in SUA were related to risk of all-cause mortality. These associations were similar across different baseline SUA categories. Consistent results were observed in alternative measures of SUA variability. Moreover, individuals with higher variability in SUA were more related to common risk factors than those with stable SUA.

Conclusions

Higher variability in SUA was independently associated with the risk of all-cause mortality irrespective of baseline SUA and direction of variability in the general population.

Triglyceride-glucose index and the risk of stroke and its subtypes in the general population: an 11-year follow-up

Background

Triglyceride-glucose (TyG) index was recently suggested to be a reliable surrogate marker of insulin resistance. We aim to investigate the associations between baseline and long-term TyG index with subsequent stroke and its subtypes in a community-based cohort.

Methods

A total of 97,653 participants free of history of stroke in the Kailuan Study were included. TyG index was calculated as ln (fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2). Baseline TyG index was measured during 2006–2007. Updated cumulative average TyG index used all available TyG index from baseline to the outcome events of interest or the end of follow up. The outcome was the first occurrence of stroke, including ischemic stroke, intracerebral hemorrhage and subarachnoid hemorrhage. The associations of TyG index with outcomes were explored with Cox regression.

Results

During a median of 11.02 years of follow-up, 5122 participants developed stroke of whom 4277 were ischemic stroke, 880 intracerebral hemorrhage, and 144 subarachnoid hemorrhage. After adjusting for confounding variables, compared with participants in the lowest quartile of baseline TyG index, those in the third and fourth quartile were associated with an increased risk of stroke (adjusted hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.12–1.33, and adjusted HR 1.32, 95% CI 1.21–1.44, respectively, P for trend < 0.001). We also found a linear association between baseline TyG index with stroke. Similar results were found for ischemic stroke. However, no significant associations were observed between baseline TyG index and risk of intracranial hemorrhage. Parallel results were observed for the associations of updated cumulative average TyG index with outcomes.

Conclusions

Elevated levels of both baseline and long-term updated cumulative average TyG index can independently predict stroke and ischemic stroke but not intracerebral hemorrhage in the general population during an 11-year follow-up.

Prevalence of the Metabolic Syndrome and its components in the Brazilian adult population

We estimated the prevalence of the Metabolic Syndrome (MetS) and its components in the Brazilian population according to sociodemographic factors. This is a cross-sectional population-based study that used laboratory data from the National Health Survey. We estimated the prevalence of MetS and its components with 95% confidence intervals and the unadjusted and adjusted prevalence ratio (PR) with the Poisson regression. MetS prevalence ratio was 38.4%. High waist circumference (WC) (65.5%) and low HDL cholesterol (49.4%) were the most prevalent components, including in the youngest people. MetS and its components were more frequent among women (41.8%), individuals with low schooling (47.5%), and older adults (66.1%). In the adjusted analysis, females (PR = 1.16; 95% CI 1.08-1.24), older adults (PR = 3.69; 95% CI 3.26-4.17), and low schooling (PR = 1.32; 95% CI 1.17-1.49) were associated with MetS. MetS was prevalent in the Brazilian population, especially among women, individuals with low schooling, and older adults. High WC and low HDL cholesterol were the most prevalent components, with the aggravating high prevalence factor in young adults. These findings reveal the need to consider laboratory data for a more accurate analysis of this condition, which can be challenging at the national level.