Impact of different interventions on cardiovascular risk factors

Abstract: Obesity and related complications such as diabetes mellitus type 2 (T2DM) and cardiovascular events are a growing major health problem worldwide. Achieving a negative energy balance by increasing physical activity in combination with reduced caloric intake, is the most common approach in weight reduction strategies, something that is difficult to maintain in the long term. Other strategies to increase energy expenditure may include enhancing resting metabolic rate (RMR) by increasing heat production or energy consumption in muscle tissue.Regular exercise is often recommended as part of the treatment and prevention of cardiovascular disease (CVD) and it is expected to ameliorate risk factors associated with the metabolic syndrome, such as glucose and insulin metabolism, lipid profile and blood pressure. However, extreme exercise performance seems to have potential unbeneficial effects on inflammation, oxidation, and cardiac health. We intended to study the impact of a more common way of exercise in different cardiovascular risk factors and how natural antioxidants, protein supplementation or hypercaloric diet could influence the results.In patients with already established T2DM, it is important to find new and easy to manage markers for CVD, as it is the main cause of morbidity and mortality in this patient group.  Even if quality of life (QoL) is strongly related to CVD in patients with T2DM, it is still not incorporated in routinary clinical assessments. Paper I: Resistance training (RT) performed by healthy men for three months, increased lean body-mass and RMR. The increase of RMR was dependent on both an increase in muscle mass and a higher RMR per kg of muscle tissue. Even if it was equally efficient to combine training with whey protein supplementation or with increased energy intake, hyperalimentation with an extra intake of a fast-food resulted in an impaired cardiovascular profile, with reduced insulin sensitivity and higher ApoB levels. Thus, regularly performed RT could be helpful in the treatment of obesity by increasing RMR.Paper II: Regularly running 5 km for 4 weeks resulted in a positive outcome, leading to lower insulin and triglyceride levels, higher HDL cholesterol, and a tendency to lower inflammation when compared with a period of minimal physical activity. However, Troponin-T, marker of myocardial injury, was detectable after a 5 km race at maximal speed in almost half of the races. Consuming blueberries showed a cardioprotective effect, blunting troponin-T release and improving the lipid profile. Less positive was the increase of fasting glucose in consumers of blueberries, which could be an indirect effect of concomitant diet.Paper III: Running 5 km at maximal speed may not be as advantageous for cardiovascular health as expected, at least when looking at the acute effects of a single race in healthy young individuals. A relative short race seemed to reduce insulin sensitivity and despite increased insulin levels, glucose was higher directly after the race compared with a resting day. Indeed, we found elevated cortisol and Troponin-T levels after the races, which suggests that running a distance that is common among recreational runners, may not be fully advantageous for cardiovascular health when performed in a strenuous way.Paper IV: Healthy participants who were randomized to wear a cooling vest daily for two months, reached an improved lipid profile. Furthermore, in the sub-group who were overweight and used the vest more frequently, we observed a weight reduction and an ameliorated glucose profile. To induce cold by using a cooling vest regularly, could be advantageous in the treatment and prevention of obesity and metabolic syndrome.Paper V: We investigated if selected questions regarding the domains “general mental health and well-being” and “vitality”, from QoL measurement instrument SF-36, could predict cardiovascular events and death in patients with T2DM in primary care. These two questions: “During the last 4 weeks, did you feel full of pep?” and “During the last 4 weeks, did you have a lot of energy?” resulted markers for major adverse cardiovascular events (MACE) independently of traditional vascular risk factors as well as arterial stiffness.