A cross-sectional and longitudinal study between association of n-3 polyunsaturated fatty acids derived from fish consumption and high-density lipoprotein heterogeneity

Gender differences in the associations among fish intake, lifestyle, and non-HDL-C level in Japanese subjects over the age of 50 years: Anti-atherosclerotic effect of fish consumption

BACKGROUND AND AIMS

Higher fish consumption may lead to the suppression of atherogenesis. The present study was aimed at investigating the gender differences in association with the frequency of fish intake, lifestyle behaviors and serum non-high-density lipoprotein cholesterol (non-HDL-C) levels.

METHODS AND RESULTS

This cross-sectional study was conducted in a cohort of 4320 (2479 males, 1570 females) healthy Japanese subjects over 50 years of age registered at the Health Planning Center of Nihon University Hospital between April 2018 and March 2019. The average weekly frequency of fish intake was 2.58 ± 1.39 days in males and 2.42 ± 1.36 days in females. In males, the serum non-HDL-C level decreased significantly as the weekly frequency of fish intake (0-1 days, 2-3 days, 4-5 days, or 6-7 days) increased (p < 0.0001). Multiple stepwise regression analysis identified the weekly frequency of fish intake (β = -0.056, p = 0.004) and habitual aerobic exercise (β = -0.063, p = 0.001) as independent determinants of the serum non-HDL-C level. On the other hand, no such associations were observed in females. However, the proportion of subjects engaging in habitual aerobic exercise increased as the frequency of fish intake increased even among females.

CONCLUSIONS

A higher frequency of fish intake may be associated with healthier lifestyle behaviors and lower non-HDL-C levels in males, but not in females. There appear to be gender differences in the relationships between the intake of fish and lifestyle behaviors on lipid metabolism.

CLINICAL TRIAL REGISTRATION

umin (http://www.umin.ac.jp/) Study ID: UMIN000035899.

Prevention of Endothelial Dysfunction and Cardiovascular Disease by n-3 Fatty Acids-Inhibiting Action on Oxidative Stress and Inflammation

BACKGROUND

Prospective cohort studies and randomized controlled trials have shown the protective effect of n-3 fatty acids against cardiovascular disease (CVD). The effect of n-3 fatty acids on vascular endothelial cells indicates their possible role in CVD prevention.

OBJECTIVE

Here, we describe the effect of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on endothelial dysfunction-caused by inflammation and oxidative stress-and their role in the development of CVD.

METHODS

We reviewed epidemiological studies done on n-3 fatty acids in CVD. The effect of DHA and EPA on vascular endothelial cells was examined with regard to changes in various markers, such as arteriosclerosis, inflammation, and oxidative stress, using cell and animal models.

RESULTS

Epidemiological studies revealed that dietary intake of EPA and DHA was associated with a reduced risk of various CVDs. EPA and DHA inhibited various events involved in arteriosclerosis development by preventing oxidative stress and inflammation associated with endothelial cell damage. In particular, EPA and DHA prevented endothelial cell dysfunction mediated by inflammatory responses and oxidative stress induced by events related to CVD. DHA and EPA also increased eNOS activity and induced nitric oxide production.

CONCLUSION

The effects of DHA and EPA on vascular endothelial cell damage and dysfunction may involve the induction of nitric oxide, in addition to antioxidant and anti-inflammatory effects. n-3 fatty acids inhibit endothelial dysfunction and prevent arteriosclerosis. Therefore, the intake of n-3 fatty acids may prevent CVDs, like myocardial infarction and stroke.

Administration of eicosapentaenoic acid may alter lipoprotein particle heterogeneity in statin-treated patients with stable coronary artery disease: A pilot 6-month randomized study

BACKGROUND

We hypothesized that the addition of eicosapentaenoic acid (EPA) to ongoing statin therapy could change the particle heterogeneity of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles, even in stable coronary artery disease (CAD) patients.

METHODS

We assigned CAD patients already receiving statin therapy to one of two groups: an EPA group (1800 mg/day; n = 30) and a control group (n = 30). A gel permeation high-performance liquid chromatography method was used to measure the particle concentration and number of lipoprotein subclasses.

RESULTS

In the EPA group, significant decreases of both the concentration and number of medium LDL (p = 0.0002 and 0.0001), small LDL (p = 0.0004 and 0.0005) and very small LDL (p = 0.0005 and 0.002) particles were observed. Conversely, the concentration and number of large HDL particles increased significantly (p = 0.024 and 0.048). The concentration of very large HDL particles also increased significantly (p = 0.028). Furthermore, significant correlations between the variables that showed significant changes in the LDL and HDL particle subclasses, and the EPA/arachidonic acid (AA) ratio were found. No other significant associations of lipoprotein particle heterogeneity with the serum EPA/AA ratio were noted in either the control group or the EPA group. Interestingly, univariate and multivariate regression analyses revealed that increased serum lecithin-cholesterol acyltransferase activity, a key enzyme of HDL cholesterol efflux, was a predictor for increased above-mentioned HDL particles subclasses.

CONCLUSIONS

Administration of EPA might alter both LDL and HDL particle heterogeneity, causing decreased concentration and number of smaller LDL particles and increased concentration and number of larger HDL particles. Furthermore, addition of EPA to ongoing statin therapy appears to be capable of increasing the EPA/AA ratio, which might have an anti-atherosclerotic effect on lipoprotein particle heterogeneity, even in stable CAD patients with well-controlled serum lipid levels.

CLINICAL TRIAL REGISTRATION

UMIN (http://www.umin.ac.jp/) Study ID: UMIN000010452.

Association of lecithin-cholesterol acyltransferase activity and low-density lipoprotein heterogeneity with atherosclerotic cardiovascular disease risk: a longitudinal pilot study

BACKGROUND

Lecithin-cholesterol acyltransferase (LCAT) is believed to be involved in reverse cholesterol transport, which is known to play a key role in suppression of atherosclerosis. However, recent investigations have demonstrated that higher LCAT activity, measured in terms of the serum cholesterol esterification rate by an endogenous substrate method, is associated with increased formation of triglyceride (TG)-rich lipoproteins (TRLs), leading to a decrease in the low-density lipoprotein (LDL) particle size. The purpose of this hospital-based longitudinal study was to clarify the causal relationship between changes in the LCAT activity and changes in the LDL-particle size.

METHODS

The subjects were a total of 335 patients, derived from our previous study cohort, with one or more risk factors for atherosclerotic cardiovascular disease (ASCVD). For this study, we measured the LDL-particle size (relative LDL migration [LDL-Rm value]) by polyacrylamide gel electrophoresis in the subjects, along with the changes in the LCAT activity, at the end of a follow-up period of at least 1 year.

RESULTS

The results revealed that the absolute change (Δ) in the LDL-particle size increased significantly as the quartile of Δ LCAT activity increased (p = 0.01). A multi-logistic regression adjusted-analysis revealed that Δ LCAT activity in the fourth quartile as compared to that in the first quartile was independently predictive of an increased LDL-particle size (odds ratio [95% confidence interval]: 2.03 [1.02/4.04], p = 0.04). Moreover, the ∆ LCAT activity was also positively correlated with ∆ TRL-related markers (i.e., TG, remnant particle-like cholesterol [RLP-C], apolipoprotein B, apolipoprotein C-2, and apolipoprotein C-3).

CONCLUSIONS

The results lend support to the hypothesis that increased LCAT activity may be associated with increased formation of TRLs, leading to a reduction in the LDL-particle size in patients at a high risk for ASCVD. To reduce the risk of ASCVD, it may be important to focus not only on the quantitative changes in the serum LDL-cholesterol levels, but also on the LCAT activity.

TRIAL REGISTRATION

UMIN ( https://upload.umin.ac.jp/cgi-bin/ctr/ctr_reg_list.cgi ) Study ID: UMIN000033228 retrospectively registered 2 July 2018.

Does administration of eicosapentaenoic acid increase soluble thrombomodulin level in statin-treated patients with stable coronary artery disease?

Interventions targeting the serum eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio could be useful for the prevention of coronary artery disease (CAD). Few data exist regarding the effects of administration of EPA on the serum levels of soluble thrombomodulin (sTM) as a marker of endothelial damage, or on the relationship between the sTM and EPA/AA ratio in patients with CAD receiving statin treatment. We assigned stable CAD patients already receiving statin therapy to an EPA group (1800 mg/day: n = 50) or control group (n = 50). A significant increase of the sTM level was observed in the EPA group as compared to that in the control group 0.40 (0.10/0.70) FU/mL vs. 0.20 (0/0.40) FU/mL, p = 0.004 at the 6-month follow-up examination. Multivariate regression analysis after adjustments for coronary risk factors and changes of the serum lipid levels identified an increased EPA/AA ratio as an independent predictor of increased serum sTM level (β = 0.244, p = 0.02). The results suggest that an increased sTM level caused by additional administration of EPA to statin might be associated with an increased EPA/AA ratio. The increase of the serum sTM after administration of EPA might reflect an increase of the TM expression on the endothelial surface rather than endothelial damage in CAD patients under statin treatment.Clinical Trial Registration Information UMIN ( http://www.umin.ac.jp/ ), Study ID: UMIN000010452.

Increased triglyceride/high-density lipoprotein cholesterol ratio may be associated with reduction in the low-density lipoprotein particle size: assessment of atherosclerotic cardiovascular disease risk

Hypertriglyceridemia, which often leads to both low-density lipoprotein (LDL) and high-density lipoprotein (HDL) metabolic disorders, is a strong risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). We hypothesized that the triglyceride (TG)/HDL cholesterol (TG/HDL-C) ratio may be more useful for estimation of the LDL-particle size, as a well-known risk factor for ASCVD, as compared to the serum TG level per se. Polyacrylamide gel electrophoresis was used in this study to estimate the LDL-particle size [relative LDL migration (LDL-Rm value)] in 649 consecutive patients with one additional risk factor for ASCVD. Multivariable regression analysis identified both serum TG (β = 0.556, p < 0.0001) and the serum TG/HDL-C ratio (β = 0.607, p < 0.0001) as independent indicators of the LDL-particle size. In terms of evaluation of the accuracy of indicators of LDL-Rm values equal to or greater than 0.40, which are suggestive of the presence of large amounts of small-dense LDL and represent the upper limit (mean + 2 standard deviation) of the normal range in this population, both the serum TG level and serum TG/HDL-C ratio showed high accurate areas under the receiver-operating characteristic curve (0.900 vs. 0.914), but with a negative likelihood ratio of 0.506 vs. 0.039, indicating that the TG/HDL-C ratio model is superior for excluding patients with values below the cutoff value and with LDL-Rm values ≥ 0.40. Furthermore, in 456 patients followed up for at least 1 year, multivariable regression analysis identified increased serum TG/HDL-C ratio as an independent predictor of a decreased LDL-particle size. These results suggest that the serum TG/HDL-C ratio may be more useful for assessing the risk of ASCVD as compared to the serum TG level per se. To reduce the risk of ASCVD, it may be important to focus not only on changes of the serum LDL-C, but also on those of the serum TG/HDL-C ratio.

A longitudinal study of the association of the eicosapentaenoic acid/arachidonic acid ratio derived from fish consumption with the serum lipid levels: a pilot study

It has been demonstrated that regular fish consumption is associated with a reduced mortality from atherosclerotic cardiovascular disease (ASCVD). However, data are scarce regarding the correlation between the changes in the serum eicosapentaenoic acid/arachidonic acid (EPA/AA) ratio associated with regular fish consumption and the changes in the serum lipid profile variables. This study was designed as a hospital-based longitudinal study to investigate the relationship between the changes in the serum EPA/AA ratio and changes of the serum lipid levels in patients with one or more risk factors for ASCVD. In 475 patients followed-up for at least 1 year, univariable and multivariable regression analyses conducted after adjustments for the risk factors of ASCVD revealed that the absolute change of the EPA/AA ratio (∆EPA/AA ratio) was independently and significantly associated with the changes of the serum levels of low-density lipoprotein cholesterol (LDL-C) (β = - 0.129, p = 0.005), triglyceride (TG) (β = - 0.108, p = 0.019), non-high-density lipoprotein cholesterol (non-HDL-C) (β = - 0.149, p = 0.001), and TG/HDL-C ratio, a marker of the LDL particle size (β = - 0.104, p = 0.02), while not being correlated with any other lipid parameters. On the other hand, while the ∆ docosahexaenoic acid (DHA)/AA ratio was inversely correlated with the changes of the serum HDL-C level and positively correlated with the changes of the TG/HDL-C ratio, possibly serving to promote development of atherosclerosis. The results suggest that an increase of the EPA/AA ratio might be associated with decrease of the serum levels of LDL-C, TG and non-HDL-C levels, as well as with an increase of the TG/HDL-C ratio, which represents increased LDL particle size, all of which play a role in the development of ASCVD. A high EPA/AA ratio, but not DHA/AA ratio, derived from fish consumption might reduce the risk of ASCVD through reducing the risk of development of atherosclerosis.Clinical Trial Registration Information: UMIN ( http://www.umin.ac.jp/ ), Study ID: UMIN000010603.