Background
In the last centuries, life expectancy in industrialized nations has doubled. Many people reach an advanced age, but the period of life in which a manifest cardiovascular disease has to be treated, is continuously lengthening. Vascular biomarkers and risk scores are used to determine cardiovascular risk. In recent years, however, there has been a shift toward measures of healthy lifestyle, which are more focused on determining health potential. However, the relationship between lifestyle, especially nutrition and physical activity, and the traditionally used biomarkers is still poorly understood.

Aims
This PhD project had several aims. The first one was to validate a visually aided dietary assessment tool (DAT). Second, this project aimed at comparing various lifestyle metrics, calculated as a cardiovascular health score, and their influence on the structure and function of large human arteries in both a healthy Swiss (aged 50+ years old) and Finnish (aged 55-74 years old) population. Third, the effects of a 4-year lifestyle-based intervention on carotid structure in the same Finnish population were analyzed, to determine if atherosclerotic progression could be slowed.

Methods
The DAT was validated against a weighed seven-day food record (7d-FR). Young (20-40 years old) and older (50-70 years old) adults were recruited. The DAT was compared to the 7d-FR for total energy intake, macronutrients, sugar, water, and portions of fruits and vegetables. The Finnish Dose-Responses to Exercise Training (DR’s EXTRA) study was a randomized-controlled trial lasting four years that consisted of six groups: aerobic exercise, resistance exercise, diet, aerobic exercise + diet, resistance exercise + diet, and reference. Carotid intima-media thickness (cIMT), and lumen diameter (cLD) were used as vascular biomarkers to quantify atherosclerotic progression during the intervention and were measured by transcutaneous ultrasound using state-of-the-art wall contour detection techniques.
In a cross-sectional approach of the DR’s EXTRA study, adherence to the American Heart Association’s “Life’s Simple 7” cardiovascular health score, consisting solely of modifiable lifestyle metrics, was compared with cIMT and cLD, as well as carotid distensibility. The Life’s Simple 7 score was divided into poor, intermediate, and ideal cardiovascular health.
The Swiss cross-sectional Cardiopulmonary Exercise Testing (COmPLETE) study included a healthy sample of the Swiss population. For this PhD project, only a sub-sample aged 50-91 years old was considered. The Life’s Simple 7 were also used to determine cardiovascular health and were compared to arterial properties, namely cIMT, cLD, carotid distensibility coefficient (DC), flow-mediated dilation (FMD), and brachial-ankle pulse wave velocity (baPWV).
Results
DAT: 51 participants were included. Correlations between the DAT and the 7d-FR ranged from 0.288 (sugar, p