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Oxidative Medicine and Cellular Longevity
Volume 2016, Article ID 2572606, 11 pages
http://dx.doi.org/10.1155/2016/2572606
Research Article

Effects of Polyphenol, Measured by a Biomarker of Total Polyphenols in Urine, on Cardiovascular Risk Factors After a Long-Term Follow-Up in the PREDIMED Study

1Departament of Nutrition and Food Science, XaRTA, INSA, School of Pharmacy, University of Barcelona, Barcelona, Spain
2Biomedical Research Networking Center-Physiopathology of Obesity and Nutrition (CIBEROBN), Carlos III Health Institute (ISCIII), Government of Spain, Madrid, Spain
3Department of Internal Medicine, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
4Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain
5IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
6Cardiovascular Risk and Nutrition Research Group (CARIN, Regicor Study Group), Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
7Department of Epidemiology, Preventive Medicine and Public Health, School of Medicine, University of Valencia, Valencia, Spain
8Human Nutrition Unit, University Hospital of Sant Joan de Reus, Department of Biochemistry and Biotechnology, Faculty of Medicine and Health Sciences, IISPV, Rovira i Virgili University, Reus, Spain

Received 24 August 2015; Revised 16 October 2015; Accepted 21 October 2015

Academic Editor: Ilaria Peluso

Copyright © 2016 Xiaohui Guo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Several epidemiological studies have shown an inverse association between the consumption of polyphenol-rich foods and risk of cardiovascular diseases. However, accuracy and reliability of these studies may be increased using urinary total polyphenol excretion (TPE) as a biomarker for total polyphenol intake. Our aim was to assess if antioxidant activity, measured by a Folin-Ciocalteu assay in urine, is correlated with an improvement in cardiovascular risk factors (blood pressure and serum glucose, cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride concentrations) in an elderly population at high risk. A longitudinal study was performed with 573 participants (aged 67.3 ± 5.9) from the PREDIMED study (ISRCTN35739639). We used Folin-Ciocalteu method to determine TPE in urine samples, assisting with solid phase extraction. Participants were categorized into three groups according to changes in TPE. Multiple linear regression models were used to assess relationships between TPE and clinical cardiovascular risk factors, adjusting for potential confounders. After a 5-year follow-up, significant inverse correlations were observed between changes in TPE and plasma triglyceride concentration (; ), glucose concentration (; ), and diastolic blood pressure (; ). Our results suggest that the consumption of more polyphenols, measured as TPE in urine, could exert a protective effect against some cardiovascular risk factors.