Cross-sectional and prospective relationships of apoA-I and apoB100 with subclinical atherosclerosis

2018 Fiscal Year Research-status Report

• Project/Area Number: 17K15826
• Research Institution: Shiga University of Medical Science
• Principal Investigator: ZAID MARYAM 滋賀医科大学, アジア疫学研究センター, 客員助教 (80780733)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: atherosclerosis / apoA-I / apoB

Outline of Annual Research Achievements

Participant serum apoA1 and apoB have been measured and data was received at the end of 2018. Thus far, cross-sectional analysis on the relationships of apoA1 and apoB with cIMT in comparison to those of their lipid counterparts, HDL particle and LDL particle has been completed. We have found that although the apoproteins have significant relationships with cIMT, a marker of subclinical atherosclerosis, these relationships are not independent of their lipid counterparts. Thus, suggesting that HDL and LDL particles have stronger and more robust relationships with subclinical atherosclerosis, as measured by carotid intima-media thickness or cIMT.
Cross-sectional analysis of SESSA baseline dataset shows that although HDL and LDL particles are strongly correlated with their apoprotein counterpart: apoA1 and apoB, respectively, they have differing strengths of relationships with carotid intima-media thickness (cIMT). Individually, apoA1 and apoB have significant positive and inverse relationships, respectively, with cIMT. The same is identified when assessing HDL and LDL particles alone. However, once we include the lipid counterpart of the apoproteins, ie. apoA1 and HDL particle in the same model, the significant relationship apoA1 with cIMT is abolished. Similarly with apoB and LDL particle. Interestingly, however, when we look at the relationship of HDL or LDL particle with adjustments made for apoA1 or apoB, a significant relationship with cIMT remains. These results suggest an important relationship for lipid particles with atherosclerosis.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

Since we have received the measurements of serum apoA1 and apoB, the analysis of these data with our previous data from SESSA baseline and follow-up studies is progressing smoothly. We have completed cross-sectional analysis to our satisfaction and expectations. We will now continue the longitudinal analysis, as well as assessment of other measures of subclinical atherosclerosis.

Strategy for Future Research Activity

Thus far, we have completed cross-sectional analyses of apoproteins and their relationships with HDL and LDL particles and with cIMT. We will next assess other measures of subclinical atherosclerosis ( coronary artery calcification and carotid plaque counts) with apoA1 and apoB, as well as compare these relationships to those of the lipid particles.
We also will assess longitudinal relationships to determine if changes in apoprotein levels are synonymous with changes in subclinical atherosclerosis (cIMT, coronary calcification and carotid plaque counts). These analyses are expected to be completed soon and a manuscript for this study will be prepared within the coming months. We aim to publish in an international peer-reviewed journal related to lipids and atherosclerosis.

Causes of Carryover

There are some remaining grant funding as the research has been delayed due to measurement of serum samples. We plan to use this amount for annual statistical software license (SAS) and for attending an academic conference on atherosclerosis in Japan.