Nutrition and cardiometabolic risk: a prospective population-based cohort study

Abstract

Cardiovascular diseases (CVD) are the principal cause of mortality worldwide. Lifestyle plays a crucial role in preventing the development of CVD, and one of its key elements is diet, which directly affects cardiometabolic health and cardiovascular risk. Given the complexity of diet and also of cardiovascular disease etiology, a lot of recent research into the association between diet and disease have focused on dietary patterns, as this is currently the most holistic way to study dietary habits in the population. In this work, we examined dietary patterns and their components that are associated with cardiometabolic health. Data were obtained from two population-based cross-sectional surveys conducted in Girona (Spain) in 2000 and 2005. The first survey included 3,058 randomly selected free-living men and women aged 25 to 74 years. The second survey included 6,352 men and women aged 35 to 80 years. These cohorts were re-examined in 2010 and 2012, with a follow up rate of 80.6% and 78.0%, respectively. At baseline and follow-up, we collected data on diet, using a validated food frequency questionnaire (FFQ), and on cardiovascular risk. We performed validation studies of a priori and a posteriori dietary patterns. In the a priori analysis, we found that a Diet Quality Index derived from a short Diet Quality Screener had good ability to predict future cardiovascular health complications. The a posteriori analysis showed good reproducibility and modest validity of dietary patterns defined using cluster analysis of the FFQ data. In a further step, we analysed the impact of energy under-reporting on dietary patterns and secular trends in dietary patterns. We concluded that energy under-reporting is a serious problem in nutritional epidemiology, especially when developing dietary guidelines for the general population, and more solid research is urgently needed in this area. To explore the association between diet and cardiovascular risk factors and CVD, we focused on abdominal obesity, a risk factor that had received increasing interest in recent years. Adherence to the Mediterranean diet and substitution of soft drinks with other caloric beverages, such as milk and juice, was associated with decreased abdominal adiposity. Finally, we studied the association between dairy products and cardiovascular events, and concluded that consumption of dairy products does not have an adverse impact on CVD incidence, and that frequent intake of yogurt was negatively associated with CVD incidence, presumably due to its prebiotic properties.

In conclusion, this PhD research shows a smaller increase in waist circumference among individuals with high adherence to the Mediterranean diet, and the opposite for soft drink consumption. Furthermore, the results support the hypothesis that yogurt consumption is cardioprotective. Finally, it underlines the need to control for energy misreporting in epidemiological studies, and to validate dietary patterns.

En este trabajo, hemos examinado qué patrones dietéticos y cuáles de sus componentes están asociados con la salud cardiometabólica. Los datos se han obtenido a partir de dos estudios transversales de base poblacional realizados en España en 2000 y 2005. El primer estudio incluyó 3.058 y el segundo - 6.352 hombres y mujeres de 25 a 80 años de edad. Estas dos cohortes fueron re-examinadas en el año 2010 y 2012. Al inicio y al final del estudio se recogieron los datos dietéticos y los datos sobre los factores de riesgo cardiovascular. En el análisis a priori, encontramos que el Índice de Calidad Alimentaria derivado de un Cuestionario corto de Calidad de la Dieta tenía buena capacidad para predecir acontecimientos relacionados con la salud cardiovascular. El análisis a posteriori mostró una buena reproducibilidad y una validez modesta de los patrones dietéticos definidos mediante análisis de clústers de los datos de un cuestionario de frecuencia de alimentos. En el análisis del impacto de la declaración inferior de los niveles reales de energía consumida sobre los patrones dietéticos y las tendencias seculares en los mismos, llegamos a la conclusión de que la energía declarada por debajo de valores reales es un problema grave en la epidemiología nutricional, sobre todo en el desarrollo de guías alimentarias para la población en general. El seguimiento de una dieta mediterránea y la substitución de las bebidas gaseosas por otras bebidas calóricas, se asoció con una disminución de la adiposidad abdominal, un factor de riesgo de enfermedades cardiovasculares (ECV). Por último, llegamos a la conclusión de que el consumo frecuente de yogur se asoció negativamente con la incidencia de ECV.

En conclusión, esta investigación doctoral muestra un menor aumento de la circunferencia de la cintura entre los individuos que siguen una dieta mediterránea, y lo contrario para el consumo de bebidas gaseosas. Además, los resultados apoyan la hipótesis de que el consumo de yogur actúa como cardioprotector. Por último, subraya la necesidad de controlar la declaración errónea del consumo de energía en los estudios epidemiológicos, y de validar los patrones dietéticos.