Identifying and comparing cut-off points for the omega-3 index related to cardiometabolic risk factors in Brazilian and Puerto Rican middle-aged adults

• Grant number: 22/11755-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: April 01, 2023
• End date: March 31, 2024
• Field of knowledge: Health Sciences - Nutrition - Nutritional Analysis of Population
• Principal Investigator: Regina Mara Fisberg
• Grantee: Lais Duarte Batista
• Supervisor: Josiemer Mattei
• Host Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Harvard University, Cambridge, United States
• Associated to the scholarship: 20/09451-9 - Fat consumption and cardiometabolic risk in residents of the city of São Paulo: dietary intake and cardioprotective potential considering polymorphisms in the FADS1 and FADS2 genes, BP.DR

Abstract

Dietary fat intake has been linked to cardiovascular diseases over the decades, but some inconsistent findings are still debated. The use of biomarkers can contribute to a better understanding of the impacts of n-3 PUFAs on health, such as the omega-3 index defined as the sum of eicosapentaenoic and docosahexaenoic omega-3 fatty acids in erythrocyte membranes. However, using internationally adopted arbitrary cut-off values may not be accurate for populations with different backgrounds and ethnic groups. Thus, the present study aims at identifying and compare cut-off points for the omega-3 index related to cardiometabolic risk factors in Brazilian and Puerto Rican middle-aged adults. This cross-sectional study uses data from two population-based studies: The 2015 Health Survey of São Paulo with a Focus on Nutrition and the Boston Puerto Rican Health Study. In both studies, blood samples were collected after at least 12h fasting and erythrocyte fatty acids composition was quantified using a gas chromatograph with a flame ionization detector (Shimadzu, CG-2010, Kyoto, Japan). Cardiometabolic risk factors of interest include total cholesterol, HDL-c, LDL-c, triglycerides, waist circumference, fasting plasma glucose, insulin resistance, and body mass index. An independent t-test will test differences between studies or the Mann-Whitney test and associations will be investigated by multiple regression models. ROC curve analysis will explore the cutoff values of the omega-3 index in each study in relation to the presence/absence of the cardiometabolic risk factors of interest. Statistical analyses will be performed using RStudio (version 1.2.5019), with a significance level of 5%. (AU)