Comparison of cardiovascular disease risk associated with 3 lipid measures in Japanese adults

Validation of the Martin method to estimate low-density lipoprotein cholesterol concentrations in Japanese populations and a modified method for laboratory information system application

OBJECTIVES

High concentrations of low-density lipoprotein cholesterol (LDL-C) are a risk factor for cardiovascular disease. We validated the efficacy of the Martin method is useful in the estimation of LDL-C concentrations was validated in Japanese populations and derived a modified Martin method for easy laboratory information system applications.

METHODS

We created 3 subject groups, including 2664 health check-up participants registered with the Resource Center for Health Science, 29,806 clinical patients (A) in the Gifu University Hospital, and 113,716 clinical patients (B) in the Fujita Health University Hospital. Each method to estimate serum LDL-C concentrations (Friedewald formula, Martin method and modified Martin method) was validated by correlation analysis with serum LDL-C concentrations measured using a direct method.

RESULTS

The correlation coefficients with the direct method in terms of the Friedewald formula, Martin method, and modified Martin method were 0.963, 0.972 and 0.970 in the health check-up participants; 0.946, 0.962 and 0.961 in clinical patients A; and 0.961, 0.979 and 0.978 in clinical patients B, respectively. Concordance ratios with using the direct method in the Friedewald formula, Martin method and modified Martin method were 82.8%, 85.5% and 85.3% in the health check-up participants; 76.4%, 80.5% and 80.2% in clinical patients A; and 76.1%, 82.6% and 82.6% in clinical patients B, respectively.

CONCLUSION

Our results show that the Martin and modified Martin methods display good performance in terms of the estimation of LDL-C concentrations among triglyceride concentrations of a wide range, and they may thus be useful for estimating LDL-C concentrations.

Changes in Total Cholesterol and Heart Rate in Normotensive and Hypertensive Rats under Combined Influence of Cold Exposure and Hypokinesia

We studied the effect of hypokinesia alone and in combination with cold exposure on HR and total cholesterol content in the blood serum of Wistar, WKY, and SHR rats. Irrespectively of the season, hypokinesia was associated with a decrease in HR, which is probably a result of reduced body needs due to deceleration of metabolic processes. A significant increase in total cholesterol was found under conditions of cold exposure combined with hypokinesia, which indicates qualitative structural rearrangement of energy metabolism under the influence of environmental factors. In winter, the increase in total cholesterol concentration was more pronounced (by 51.5%) in the group of hypertensive animals. Presumably, the increase in the serum concentration of total cholesterol under conditions of hypokinesia and cold exposure is a predictor of structural changes in the heart.

Comparison Between Non-High-Density Lipoprotein Cholesterol and Low-Density Lipoprotein Cholesterol to Estimate Cardiovascular Risk Using a Multivariate Model

BACKGROUND

Although studies exist comparing low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (HDL-C) in the development of cardiovascular disease (CVD), most have limitations in the mathematical models used to evaluate their prognostic power adjusted for the other risk factors (cardiovascular risk).

OBJECTIVE

The aim of this study was to compare LDL-C and non-HDL-C in patients with CVD to determine whether both parameters predict CVD similarly.

METHODS

A cohort of 1322 subjects drawn from the general population of a Spanish region was followed between 1992 and 2006. The outcome was time to CVD. Secondary variables were gender, age, hypertension, diabetes, personal history of CVD, current smoker, body mass index, LDL-C, and non-HDL-C. Two CVD prediction models were constructed with the secondary variables, with only the lipid parameter varying (non-HDL-C or LDL-C). In the construction of the models, the following were considered: multiple imputation, events per variable of 10 or more, and continuous predictors as powers. The validation was conducted by bootstrapping obtaining the distribution of the C statistic (discrimination) and the probabilities observed by smooth curves. These results were compared in both models using graphical and analytical testing.

RESULTS

There were a total of 137 CVD events. The models showed no differences in the distributions of the C statistic (discrimination, P = .536) or in the calibration plot.

CONCLUSIONS

In our population, LDL-C and non-HDL-C were equivalent at predicting CVD. More studies using this methodology are needed to confirm these results.

Non-high-density lipoprotein cholesterol and risk of cardiovascular disease in the general population and patients with type 2 diabetes: A systematic review and meta-analysis

AIMS

To examine the relationship of non-high-density lipoprotein cholesterol (non-HDL-C) level with cardiovascular disease (CVD) risk in type 2 diabetes patients and the general population by conducting a meta-analysis.

METHODS

We made a comprehensive literature search for relevant observational studies investigating the relationship of non-HDL-C level with CVD risk in the general population and type 2 diabetes patients using the PubMed and Embase databases. Pooled risk ratio (RR) with 95% confidence intervals (CI) was calculated for the highest versus the reference lower non-HDL-Cl.

RESULTS

A total of 13 studies with 156,381 individuals were included. The pooled RR of CVD was 1.59 (95% CI 1.46-1.72) in the general population and 1.99 (95% CI 1.57-2.51) in type 2 diabetes patients. Subgroup analysis showed the similar effect of non-HDL-C on CVD risk between men (RR1.98; 95% CI 1.70-2.30) and women (RR 1.63; 95% CI 1.35-1.96). However, elevated non-HDL-C was not associated with higher risk of cardiovascular mortality in the general population (RR 1.64; 95% CI 0.96-2.80) and type 2 diabetes patients (RR 1.08; 95% CI 0.57-2.07).

CONCLUSIONS

Elevated non-HDL-C level is associated with an increased risk of CVD in the general population and type 2 diabetes patients.

Meta-analysis of serum non-high-density lipoprotein cholesterol and risk of coronary heart disease in the general population

BACKGROUND

Non-high-density lipoprotein cholesterol (non-HDL-C) has been proposed an independent risk factor for coronary heart disease (CHD). However, the magnitude of this association in the general population varied considerably.

OBJECTIVE

To investigate the association of baseline non-HDL-C level with CHD risk in the general population by conducting a meta-analysis.

METHODS

A comprehensive literature search was performed in the Pubmed and Embase until January 2017. Prospective observational studies that investigated the association between baseline non-HDL-C level and CHD risk in the general population were included. Pooled hazard ratio (HR) and corresponding 95% confidence interval (CI) were calculated for the highest vs. the lowest non-HDL-C category.

RESULTS

Seven articles with 9 independent prospective studies involving 448,732 individuals were included. Meta-analysis showed that individuals with the highest non-HDL-C level at baseline were associated with greater risk of CHD (RR 1.79; 95% CI 1.68-1.91) than those in the lowest non-HDL-C level category. Subgroup analysis suggested that the risk of CHD seemed more pronounced among men (HR 1.98; 95% CI 1.70-2.30) than among women (HR 1.63; 95% CI 1.35-1.96).

CONCLUSIONS

Higher baseline non-HDL-C level is associated with increased risk of CHD in the general population. This risk seems more pronounced in men than in women. However, gender difference in non-HDL-C level associated with CHD risk should be verified by more well-designed prospective studies.

The Ankle Brachial Index Exhibits Better Association of Cardiovascular Prognosis Than Non-High-Density Lipoprotein Cholesterol in Type 2 Diabetes

OBJECTIVE

The association between ankle brachial index (ABI) and outcomes in diabetic subjects is controversial. The purpose of this study was to evaluate whether the ABI is more strongly associated with cardiovascular outcomes comparing with non-high-density lipoprotein cholesterol (non-HDL-c).

RESEARCH DESIGN AND METHODS

A total of 452 type 2 diabetic subjects followed up for a mean of 5.8 years were grouped by ABI (<0.9 versus ≥0.9) and non-HDL-c (<100mg/dL versus ≥100mg/dL). Primary outcomes were composite events including all-cause mortality, hospitalization for coronary artery disease, stroke, revascularization, amputation and diabetic foot, and the secondary end point was all-cause mortality.

RESULTS

Intergroup differences in percentage of men, duration of diabetes, hemoglobin A1c, total cholesterol, low-density lipoprotein cholesterol, triglycerides and estimated glomerular filtration rate were significant. A total of 64 composite events and 17 deaths were recorded. A higher number of composite events occurred in the group with abnormal ABI but optimal non-HDL-c than in those with suboptimal non-HDL-c but normal ABI (29% versus 11%, P < 0.05). A similar trend was observed in all-cause mortality (11% versus 1%, P < 0.05). The ABI was the dominant risk factor for both end points after adjusting other factors (for composite events, hazard ratio = 0.02, 95% CI: 0.00-0.10, P < 0.001 and for all-cause mortality, hazard ratio = 0.01, 95% CI: 0.00-0.28, P = 0.006).

CONCLUSIONS

The ABI was more strongly associated with outcomes in diabetes than non-HDL-c. The ABI should be routinely screened in diabetes even without symptom.

Usefulness of Low-Density Lipoprotein Cholesterol and Non-High-Density Lipoprotein Cholesterol as Predictors of Cardiovascular Disease in Chinese

The predictive effect of non-high-density lipoprotein cholesterol (non-HDL-C) for cardiovascular disease (CVD) in Chinese general population has not been well demonstrated. The aim of our study was to examine the relation between non-HDL-C and CVD and compare the predictive effect of non-HDL-C and low-density lipoprotein cholesterol (LDL-C) for CVD in Chinese population. The baseline examination of 27,020 participants aged 35 to 74 years from the China Cardiovascular Health Study and the China Multicenter Collaborative Study of Cardiovascular Epidemiology was conducted in 1998 to 2001. Follow-up evaluation was conducted in 2007 to 2008 with a response rate of 79.8%. Cox proportional hazards regression models were used to obtain the multivariable-adjusted hazard ratios and 95% confidence intervals (CIs) for CVD. Compared with those with non-HDL-C level of <130 mg/dl, multivariable-adjusted hazard ratios of CVD were 1.30 (95% CI 1.04 to 1.62) and 1.93 (95% CI 1.50 to 2.47) in participants with non-HDL-C levels of 160 to 189.9 and ≥190 mg/dl, respectively. An increase of 30 mg/dl in non-HDL-C level would correspond to 15%, 24%, and 12% increase in risk of CVD, coronary heart disease, and stroke, respectively. Using likelihood ratio tests, non-HDL-C appeared to be a similar predictor for CVD incidence as LDL-C (chi-square for non-HDL-C, 18.02, p <0.001; chi-square for LDL-C, 18.90, p <0.001). In conclusion, higher non-HDL-C level is associated with the increased CVD incidence and has a similar effect as LDL-C on predicting CVD risk in Chinese.