The doctoral dissertation in the field of Epidemiology will be examined at the Faculty of Health Sciences at Kuopio Campus. The public examination will be streamed online.
What is the topic of your doctoral research? Why is it important to study the topic?
My doctoral research examined the associations between serum n-6 polyunsaturated fatty acids (PUFAs) and cardiac performance and electrophysiological outcomes in middle-aged Finnish men. This topic is important because cardiovascular disease remains the leading cause of morbidity and mortality worldwide, and diet is one of its most important modifiable risk factors. While adequate intake of n-6 PUFAs, particularly linoleic acid, has been associated with lower risks of coronary heart disease and cardiovascular mortality, the mechanisms underlying these benefits are not fully understood. By examining objective biomarkers of n-6 PUFA status alongside detailed measures of cardiac function, this research provides new insights into how dietary fats may influence cardiovascular health and supports the development of evidence-based dietary recommendations and prevention strategies.
What are the key findings or observations of your doctoral research?
The main finding was that higher serum concentrations of total n-6 PUFAs, particularly linoleic acid (LA), were associated with more favorable cardiac function parameters. Higher LA concentrations were linked to greater exercise cardiac power, higher maximal oxygen uptake, lower resting heart rate, and shorter QTc and JTc intervals, which are indicators of ventricular electrical activity. In addition, higher arachidonic acid (AA) concentrations were associated with a lower occurrence of exercise-induced myocardial ischemia, while higher dihomo-gamma-linolenic acid (DGLA) concentrations were associated with higher maximal oxygen uptake and maximal heart rate during exercise.
The most novel aspect of this research is that it investigated the relationship between n-6 PUFAs and direct measures of cardiac performance and electrophysiology rather than traditional cardiovascular disease outcomes such as heart attacks or mortality. These findings contribute to the scientific understanding of how dietary fatty acids may influence heart function and provide new evidence supporting the potential cardiovascular benefits of n-6 PUFAs, particularly LA. This knowledge may help improve future dietary recommendations and public health strategies aimed at preventing cardiovascular disease.
What are the key research methods and materials used in your doctoral research?
My doctoral research was conducted using data from the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD), a population-based cohort of middle-aged men from Eastern Finland. The main exposure variables were serum concentrations of n-6 polyunsaturated fatty acids (PUFAs), including linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA), and arachidonic acid (AA). These fatty acids were measured from fasting blood samples using gas chromatography. Cardiac function was assessed using standardized exercise stress testing, electrocardiography (ECG), blood pressure measurements, and respiratory gas analysis. The outcomes included exercise cardiac power, maximal oxygen uptake, exercise-induced myocardial ischemia, heart rate at rest and during exercise, and QTc and JTc intervals.
The doctoral dissertation of Haleh Esmaili, MSc, entitled Associations of serum n-6 polyunsaturated fatty acid concentrations with cardiac function, will be examined at the Faculty of Health Sciences. The Opponent in the public examination will be Professor Anssi Auvinen of the University of Tampere, and the Custos will be Professor Tomi-Pekka Tuomainen of the University of Eastern Finland. The public examination will be held in English.
