Physical activity decreases sudden cardiac death risk in unfit men

September 1, 2013

Physical activity decreases the risk of sudden cardiac death in unfit men, reveals research presented at the ESC Congress today by Dr. Jari Laukkanen and Dr. Magnus Hagnas from Finland.

Dr Laukkanen said: "Sudden cardiac death (SCD) accounts for approximately 50% of deaths from . SCD typically occurs shortly after the onset of symptoms, leaving little time for effective , and most cases occur outside hospital with few or no early warning signs. Finding ways to identify individuals at elevated risk of SCD would allow early interventions on risk factors to be implemented."

The current study investigated the impact of high leisure-time physical activity (LTPA) combined with cardiorespiratory fitness (CRF) on risk of SCD. It included 2,656 randomly selected men aged 42 to 60 years from the Kuopio Ischemic Heart Disease Risk Factor Study, a Finnish study of risk predictors for cardiovascular outcomes and SCD in the general population. Baseline cycle exercise test and risk factor assessment were performed in 1984-89. SCD was defined as death with cardiac origin within 24 hours after onset of symptoms.

LTPA was assessed using a 12-month physical activity questionnaire. One third of subjects had low LTPA ( <191 kcal/day, equal to around 35 minutes of slow walking or 25 minutes of jogging for a 70 kg male). CRF was assessed with a maximal symptom limited cycle exercise test and peak oxygen uptake was calculated in metabolic equivalents (MET). One third of men had a low CRF (<7.9 METs).

For the analyses the study population was divided into 4 groups: 1) high CRF and high LTPA, 2) high CRF and low LTPA, 3) low CRF and high LTPA and 4) low CRF and low LTPA. Group 1 was used as a reference. The risk of SCD was adjusted for previously established (age, smoking, , , systolic blood pressure, cholesterol, C-reactive protein, prevalent type 2 diabetes and previously diagnosed coronary heart disease).

During the mean 19 years of follow-up 193 SCDs occurred. There was a 2-fold increased risk of SCD in men with low CRF and LTPA (group 4, see figure) compared to men with high CRF and high LTPA (hazard ratio [HR] 2.0, 95% confidence interval [CI] 1.3-2.9). Men with low CRF and high LTPA (group 3) did not have a statistically significant increased SCD risk compared to men with high CRF and high LTPA (HR 1.3, 95% CI 0.9-1.8). Dr Laukkanen said: "This indicates that a higher amount of leisure-time physical activity might reduce the risk of SCD among men with low cardiorespiratory fitness."

The amount of LTPA did not affect the risk of SCD among the men with high CRF (groups 1 and 2). Dr Laukkanen said: "Our study shows that CRF is a risk factor for SCD. High leisure-time physical activity exerts a protective effect on the risk of SCD among men with low cardiorespiratory fitness but does not affect risk in men with high baseline CRF."

He added: "It is widely believed that the level of CRF is determined by physical exercise, genetics and other lifestyle factors. Our study shows that exercise training and LTPA may be especially important in individuals with low CRF. One possible explanation is that CRF can be improved with regular exercise training."

Dr Laukkanen concluded: "The importance of CRF has often been neglected in the equation of SCD risk, despite appearing to be one of the most important correlates of overall health status. Our study emphasises the importance of regular physical exercise, especially among men with low CRF. An could be used to identify individuals with low CRF and high of SCD, who should then be urged to exercise more."

Explore further: Healthy lifestyle associated with low risk of sudden cardiac death in women

Related Stories

New genetic risk factor for sudden cardiac death identified

July 12, 2011

In a large and comprehensive investigation into the underlying causes of sudden cardiac death (SCD) – a surreptitious killer of hundreds of thousands annually in the United States – researchers have discovered a ...

Risk of sudden cardiac death up for black patients with HTN

April 13, 2012

(HealthDay) -- Black patients with hypertension face a significantly increased risk of sudden cardiac death (SCD) compared with nonblack patients, even after adjusting for multiple confounding variables, according to a study ...

Increased sudden cardiac death rate among HIV patients

May 16, 2012

(HealthDay) -- Patients with HIV/AIDS have a significantly increased risk of sudden cardiac death (SCD), according to a study published in the May 22 issue of the Journal of the American College of Cardiology.

Recommended for you

No new heart muscle cells in mice after the newborn period

November 5, 2015

A new study from Sweden's Karolinska Institutet shows that new heart muscle cells in mice are mainly formed directly after birth. After the neonatal period the number of heart muscle cells does not change, and A new study ...

Nanotechnology could spur new heart treatment

October 29, 2015

A new nanoparticle developed by University of Michigan researchers could be the key to a targeted therapy for cardiac arrhythmia, a condition that causes the heart to beat erratically and can lead to heart attack and stroke.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.