*45-year study shows benefits of exercising to life expectancy
More reasons are emerging why Nigerians should get more active. People who watch Television (TV) for five or more hours a day appear to be at much greater risk of dying from a blood clot in the lung – a condition known as pulmonary embolism.
Simple steps similar to those recommended for travelers on long plane flights, such as flexing leg muscles or standing up and stretching may reduce risk.Watching a lot of television every day may increase your risk of dying from a blood clot in the lung, according to new research in the American Heart Association’s journal Circulation.
A lung blood clot, known medically as a pulmonary embolism, usually begins as a clot in the leg or pelvis as a result of inactivity and slowed blood flow. If the clot breaks free, it can travel to a lung and become lodged in a small blood vessel, where it is especially dangerous.Also, a 45-year study in middle-aged men has shown that the impact of low physical capacity on risk of death is second only to smoking. The study, published in the European Journal of Preventive Cardiology, was designed to investigate risk factors for cardiovascular disease and mortality.
Lead author and researcher in the Department of Molecular and Clinical Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden, Dr. Per Ladenvall, said: “The benefits of being physically active over a lifetime are clear. Low physical capacity is a greater risk for death than high blood pressure or high cholesterol.”
The study included 792 men from the “Study of Men Born in 1913,” a representative sample of 50 year old men in Gothenburg recruited in 1963. The study was designed to investigate risk factors for cardiovascular disease and mortality.In 1967, at 54 years of age, the 792 men did an exercise test. Of those, 656 men also did a maximum exercise test in which they pushed themselves to the limit. The remaining men were excluded from the maximum exercise test because they had a health condition that could make it unsafe. Maximal oxygen uptake, called VO2 max, was measured in a subpopulation of the 656 men using ergospirometry.
Meanwhile, from 1988 to 1990, Japanese researchers asked 86,024 participants, age 40 to 79, how many hours they spent watching TV. Over the next 19 years, 59 participants died of a pulmonary embolism.Researchers found that compared to participants who watched TV less than 2.5 hours each day, deaths from a pulmonary embolism increased by:
*70 percent among those who watched TV from 2.5 to 4.9 hours
*40 percent for each additional 2 hours of daily TV watching; and
*2.5 times among those who watched TV 5 or more hours.
Professor of public health at Osaka University Graduate School of Medicine and study corresponding author, Hiroyasu Iso, said: “Pulmonary embolism occurs at a lower rate in Japan than it does in Western countries, but it may be on the rise. The Japanese people are increasingly adopting sedentary lifestyles, which we believe is putting them at increased risk.”
Authors noted that the risk is likely greater than the findings suggest. Deaths from pulmonary embolism are believed to be underreported because diagnosis is difficult. The most common symptoms of pulmonary embolism – chest pain and shortness of breath – are the same as other life-threatening conditions, and diagnosis requires imaging that many hospitals are not equipped to provide.
Researchers accounted for several factors that might have influenced findings, including obesity, diabetes, cigarette smoking and hypertension. After the number of hours spent watching TV, obesity appeared to have the next strongest link to pulmonary embolism.
Study first author and a research fellow in public health at Osaka University Graduate School of Medicine, Japan, Dr. Toru Shirakawa, said the findings may be particularly relevant to Americans. Other studies indicate U.S. adults watch more television than Japanese adults.
“Nowadays, with online video streaming, the term ‘binge-watching’ to describe viewing multiple episodes of television programs in one sitting has become popular,” Shirakawa said. “This popularity may reflect a rapidly growing habit.”
Authors said people who watch a lot of TV could take several easy steps to reduce their risk of developing blood clots in their legs that may then move to their lungs. “After an hour or so, stand up, stretch, walk around, or while you’re watching TV, tense and relax your leg muscles for five minutes,” said Iso, noting this advice is similar to that given to travelers on long plane flights. He added that drinking water may also help and, in the long run, shedding pounds if overweight is likely to reduce risk.
The study recorded participants’ viewing habits before computers, tablets and smartphones became popular sources of information and entertainment. Authors believe new studies are needed to determine the effect of these new technologies on pulmonary embolism risk.
Meanwhile, Ladenvall said: “VO2 max is a measure of aerobic capacity and the higher the figure, the more physically fit a person is. In 1967 it was difficult to do ergospirometry in large populations, so the researchers derived a formula using the measurements in the subpopulation, and then calculated predicted VO2 max for the remaining 656 men who had done the maximum exercise test.”
After the initial examination in 1967, the men were followed up until 2012, at the age of 100 years. Several physical examinations were performed, about one every 10 years. Data on all-cause death was obtained from the National Cause of Death Registry.
To analyse the association between predicted VO2 max and mortality the men were divided into three groups (tertiles) ranging from low to high: 2.00 l/min, 2.26 l/min, and 2.56 l/min.
The researchers found that each tertile increase in predicted VO2 max was associated with a 21% lower risk of death over 45 years of follow up, and after adjusting for other risk factors (smoking, blood pressure and serum cholesterol).
Ladenvall said: “We found that low aerobic capacity was associated with increased rates of death. The association between exercise capacity and all-cause death was graded, with the strongest risk in the tertile with the lowest maximum aerobic capacity. The effect of aerobic capacity on risk of death was second only to smoking.”
“The length of follow up in our study is unique,” continued Dr Ladenvall. “When this study began, most data was derived from hospital cohorts and there was very limited data on exercise testing in a large general population. Our sample is representative of the male population in Gothenburg at that time. The risk associated with low aerobic capacity was evident throughout more than four decades and suggests that being physically active can have a big impact over a lifetime.”
He concluded: “We have come a long way in reducing smoking. The next major challenge is to keep us physically active and also to reduce physical inactivity, such as prolonged sitting.”