|Liu, Qing - Brown University|
|Lichtenstein, Alice - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Matthan, Nirupa - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Howe, Chanelle - Brown University|
|Allison, Matthew - University Of California|
|Howard, Barbara - Georgetown University|
|Martin, Lisa - George Washington University|
|Valdiviezo, Carolina - Georgetown University|
|Manson, Joann - Brigham & Women'S Hospital|
|Liu, Simin - Brown University|
|Eaton, Charles - Memorial Hospital Of Rhode Island|
Submitted to: Lipids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/19/2017
Publication Date: 7/8/2017
Citation: Liu, Q., Lichtenstein, A.H., Matthan, N.R., Howe, C.J., Allison, M.A., Howard, B.V., Martin, L.W., Valdiviezo, C., Manson, J.E., Liu, S., Eaton, C.B. 2017. Higher lipophilic index indicates higher risk of coronary heart disease in postmenopausal women. Lipids. 52(8):687-702. https://doi.org/10.1007/s11745-017-4276-8.
Interpretive Summary: Fluidity plays an important role in the activity of proteins (e.g. enzymes, carriers, and receptors) that are integral components of cell membranes and lipoprotein metabolism. The type and relative amount of fatty acids, saturated or unsaturated, are important determinants of fluidity. The lipophilic index is a calculation based on fatty acid profiles and is thought to reflect membrane and lipoprotein fluidity. Some have suggested it may also be associated with the risk of coronary heart disease. We examined the associations of lipophilic index with coronary heart disease risk among postmenopausal women. We estimated dietary lipophilic index for the cohort with completed baseline food frequency questionnaires. The cohort was free of prevalent cardiovascular diseases at entry into the Women's Health Initiative (WHI) observational study (N=85,563.) Higher dietary lipophilic index in the cohort study and plasma phospholipid lipophilic index in the case-control study were significantly associated with increased risk of coronary heart disease, after adjusting for potential confounders. Our study indicated that higher lipophilic index based on either dietary intake or plasma phospholipid fatty acid measurements, representing lower fluidity, was associated with elevated risk of coronary heart disease among postmenopausal women.
Technical Abstract: Fatty acids are essential components of cell membranes and play an integral role in membrane fluidity. The lipophilic index (LI, defined as the sum of the products between fatty acid levels and melting points (degrees Celsius), divided by the total amount of fatty acids is thought to reflect membrane and lipoprotein fluidity, and may be associated with the risk of coronary heart disease (CHD). Therefore, we examined the associations of dietary and plasma phospholipid (PL) LI with CHD risk among postmenopausal women. We determined dietary LI for the cohort with completed baseline food frequency questionnaires and free of prevalent cardiovascular diseases in the Women's Health Initiative (WHI) observational study (N=85,563). We additionally determined plasma PL LI in a case-control study (N=2428) nested within the WHI observational cohort study. Cox proportional hazard regression and multivariable conditional logistic regression were used to calculate HRs/ORs for CHD risk between quartiles of LI after adjusting for potential sources of confounding and selection bias. Higher dietary LI in the cohort study and plasma PL LI in the case-control study was significantly associated with increased risk of CHD: HR=1.12 (95%CI 1.01-1.23, P for trend=0.03) and OR=1.80 (95% CI 1.36-2.39, P for trend<0.01) comparing extreme quartiles and adjusting for socio-demographic variables, lifestyle factors, and other potential confounders. Our study indicated that higher LI based on either dietary intake or plasma PL fatty acid measurements, representing lower fatty acid fluidity, was associated with elevated risk of CHD among postmenopausal women.