According to a 29-year study published on Thursday(27) in the European Journal of Preventive Cardiology, men with high blood pressure who maintain high levels of fitness are less likely to die from cardiovascular disease.
Study author Professor Jari Laukkanen of the University of Eastern Finland, Kuopio, Finland, remarked that this was the first study to examine the combined effects of fitness and blood pressure on the risk of death from cardiovascular disease.
The results indicate that fitness plays a protective role in mitigating some of the harmful effects of high blood pressure.
Around 1.3 billion individuals in the world, aged 30 to 79 have high blood pressure or hypertension, which is a major contributor to premature death and a significant risk factor for heart attacks and strokes.
Previous research has linked high levels of cardiorespiratory fitness to longer lifespans.
In this study, the researchers investigated the connection between blood pressure, fitness, and the risk of dying from cardiovascular disease.
The Kuopio Ischaemic Heart Disease Risk Factor Study enrolled 2,280 men between the ages of 42 and 61 living in eastern Finland. The study, which took place between 1984 and 1989, involved baseline measurements of blood pressure and cardiorespiratory fitness.
The participants' maximal oxygen uptake while cycling on a stationary bike was used to assess their fitness level. Blood pressure was categorised as normal or high, while fitness was classified as low, medium, or high.
At the start of the study, the participants had an average age of 53 years, and the study followed them until 2018. Over a median follow-up period of 29 years, 644 deaths resulting from cardiovascular disease were recorded.
To analyse the risk of dying from cardiovascular disease, the researchers adjusted for a range of factors, including age, body mass index, cholesterol levels, smoking status, type 2 diabetes, coronary heart disease, use of antihypertensive medication, alcohol consumption, physical activity, socioeconomic status, and high-sensitivity C-reactive protein (an inflammation marker).
The study found that high blood pressure alone was associated with a 39% higher risk of cardiovascular mortality compared to normal values (with a hazard ratio of 1.39 and a 95% confidence interval of 1.17-1.63).
On the other hand, low levels of fitness alone were linked to a 74% increased likelihood of dying from cardiovascular disease compared to high levels (with a hazard ratio of 1.74 and a 95% confidence interval of 1.35-2.23).
The hazard ratio of 1.74 and a 95% confidence interval of 1.35-2.23 indicates that the group with a certain characteristic (e.g., high blood pressure and low fitness) has a 1.74 times higher risk of experiencing an event (e.g., cardiovascular death) than the group without that characteristic (e.g., normal blood pressure and high fitness).
The confidence interval of 1.35-2.23 suggests that if we conducted the same study multiple times, we would expect the true hazard ratio to fall within this range 95% of the time.
For instance, a hazard ratio of 2 would imply that the risk of an event occurring in one group is two times higher than the risk of the same event occurring in another group.
The study categorised participants into four groups to assess the combined effects of blood pressure and fitness on the risk of cardiovascular death. The groups were: Normal blood pressure and high fitness (used as a reference group); normal blood pressure and low fitness; high blood pressure and high fitness; and high blood pressure and low fitness.
It was found that men with high blood pressure and low fitness had more than double the risk of dying from cardiovascular disease compared to those with normal blood pressure and high fitness (with a hazard ratio of 2.35 and a 95% confidence interval of 1.81-3.04).
The study also found that when men with high blood pressure also had high fitness levels, their risk of cardiovascular disease remained elevated but was weaker.
Specifically, their risk was 55% higher than men with normal blood pressure and high fitness (with a hazard ratio of 1.55 and a 95% confidence interval of 1.16-2.07).
Professor Laukkanen commented on the findings, stating that both high blood pressure and low fitness levels were associated with an increased risk of dying from cardiovascular disease. However, high levels of fitness were found to lessen, but not eliminate, the increased risk of cardiovascular mortality in men with elevated blood pressure.
(With inputs from ANI)
