Globe and Mail: Sedentary lifestyle more dangerous to health than cardiovascular disease
Today, I read a sensationalist headline in a Globe and Mail article about a new medical study that said, "U.S. Study: Sedentary lifestyle more dangerous to health than cardiovascular disease".
This conclusion clearly defies common medical sense.
While sedentary lifestyle is an unhealthy way of life, it is a risk factor for chronic diseases including obesity, diabetes and cardiovascular diseases. That is to say, the health hazards of being sedentary are largely and ultimately manifested through an increased risk of these diseases.
How can the dangers of being sedentary itself be greater than these diseases themselves?
Curious, I tracked down the source of the information.
The Globe article claims to have been compiled from an introduction to a "recent" study in the French health magazine TOPSANTE, the Journal of the American Medical Association's International Journal of Open Access ("JAMANetworkOpen").
What does this study in JAMA say?
Actually, the JAMA research paper is no longer very "recent," published on October 19, 2018, and titled "Association of Cardiorespiratory Fitness With Long- term Mortality Among Adults Undergoing Exercise Treadmill Testing".
The cohort study included 12,207 patients who underwent a symptom-limited exercise treadmill test at the Cleveland Clinic, a prestigious U.S. medical center, between Jan. 1, 1991, and Dec. 31, 2014, and the researchers analyzed the associations between cardiorespiratory tolerance parameters they obtained during the exercise test and mortality at follow-up.
The subjects were categorized into five groups according to the cardiopulmonary tolerance data obtained during the test: the worst group, those in the lowest quartile of cardiopulmonary tolerance (<25th percentile); the lower group, those with cardiopulmonary tolerance in the 25th-49th percentile; the higher group, those with cardiopulmonary tolerance in the 50th-74th percentile; the elite group, those with cardiopulmonary tolerance in the 75th-97.6th percentile people; and the elite group, people with superb cardiorespiratory tolerance in the ≥97.7 percentile.
Mortality for these individuals was then obtained from the Social Security system, with a mean follow-up of 8.4 years.
Analysis showed an inverse relationship between all-cause mortality and cardiorespiratory tolerance in this population.
The elite group had the lowest mortality rate, which was 80% lower compared with the group with the worst cardiorespiratory tolerance; even when compared with the excellent group, the risk of mortality was 23% lower.
The low cardiorespiratory tolerance group was significantly associated with increased mortality. The risk of death in the lowest cardiorespiratory group was 5.04 times higher than in the elite group; even the lower group had a 41% increased risk of mortality compared with the higher group.
The 41% increase in risk associated with low cardiorespiratory tolerance is even higher than or equal to that of some clinical conditions, such as 29% for coronary artery disease, 41% for smoking, and 40% for diabetes.
-That's where the news headline Sedentary health risks are higher than heart disease comes from.
Even in people of advanced age (70 and older) and high blood pressure, good cardiorespiratory tolerance was significantly associated with lower mortality, by 29 percent and 30 percent, respectively.
The elite 2.5% group with superb cardiorespiratory tolerance had a lower mortality rate than all other groups, and the higher the cardiorespiratory tolerance the lower the mortality rate, with no ceiling effect limitation.
Clearly, this study evaluated the relationship between cardiorespiratory tolerance and long-term mortality.
What is cardiopulmonary tolerance?
Cardiorespiratory fitness (CRF) is defined as the ability of the circulatory, respiratory, and muscular systems to supply oxygen during sustained physical activity, and is an indicator of cardiorespiratory and muscular function, as well as a very important indicator of one's health status, and has been referred to by some as the "fifth vital sign. "
CGM is the most important indicator of a person's health.
CRF is usually expressed as metabolic equivalents (MET) or maximal oxygen uptake (VO2 max) as measured by an exercise test (e.g., flatbed treadmill or cycle ergometer).
While measurement of VO2 max in expired gas analysis can yield an equivalently accurate CRF, the methodology and equipment requirements are complex.
Therefore, it is commonly estimated clinically using maximal or submaximal (heart rate or presence of hypoxic symptoms) during treadmill or cycle ergometer exercise testing.
Measured CRF results are expressed as multiples of metabolic equivalents (MET).
We know that a MET is defined as the resting metabolic rate, which is the amount of oxygen consumed by a person sitting quietly in a chair at rest, about 3.5 milliliters/kilograms/minute of oxygen.
When converted to energy expenditure, this is 1.2 kilocalories per minute for a 70-kilogram person, which equates to 0.0167 kilocalories per minute per kilogram of body weight - a number that everyone should keep in mind to easily convert various intensities of exercise to energy or fat expenditure.
For example, a person's CRF measured at 10 METs indicates that the person's cardiorespiratory fitness can tolerate 10 times the amount of vigorous exercise at rest.
Factors affecting CRF
Each person's CRF level is affected by multiple factors, including modifiable factors: physical activity, smoking, obesity, and medical conditions (cardiorespiratory and muscular disorders); and non-modifiable factors: age, gender, and genotype (hereditary factors)
With regular physical activity being the greatest determinant of CRF in healthy individuals. factor.
Evidence from randomized controlled trials suggests a dose-response relationship between physical activity and improvement in CRF, with higher intensity and volume of activity associated with greater improvement in CRF.
In addition to regular activity, body weight is an important factor influencing CRF, and CRF in obese individuals is generally about 10-15% lower than in non-obese individuals.
Smoking is another CRF influencing factor that can be modified by lifestyle, the higher the amount of cigarettes smoked and the longer the history of smoking, the lower the CRF is about significant.
Diseases involving the circulatory, respiratory, and muscular systems can affect CRF to varying degrees, and data from several studies have shown that patients with heart disease, diabetes, or high blood pressure have CRFs that are about 10-25% lower than those of healthy individuals.
Age is a major determinant of CRF levels. After a maximum reached between the ages of 20 and 30, CRF begins to decline with age, with the rate of decline increasing with age, according to the study.
Women have smaller muscle mass, lower hemoglobin and blood volume, and lower cardiac output compared to men, and as a result, CRF is usually about 2 METs lower than that of men, with an average CRF of about 12 METs in young men and 10 METs in women.
Genetic factors also affect CRF levels, which are often referred to as individual differences in body mass.
It can be seen that although regular physical activity is the most important determinant of CRF in healthy people. However, CRF is influenced by numerous other factors at the same time and, in particular, in unhealthy people, the disease state is the more dominant determinant. For example, in people with heart failure, walking a few steps can be breathless and hard to tolerate.
The subjects in the study were hospital patients, many of whom were tested for CRF because they were symptomatic, and many of whom had comorbidities such as heart disease, diabetes, hypertension, hyperlipidemia, end-stage renal disease, and a history of smoking, among other conditions that affect CRF.
These people's low CRFs are due in large part to these conditions, not to a lack of physical activity.
So the news made the mistake of stealing a concept by directly replacing low CRF with a sedentary lifestyle, claiming that sedentary behavior is more dangerous to health than heart disease.
Not even a single word for sedentary (sedentary lifestyle) can be found in the entire paper.
The authors did a skewed reading in an interview with CNN
Where did the Globe-compiled headline-grabbing article come from?
This time it's not all Globe's fault, but one of the paper's authors who gave a skewed reading of the study in an interview with CNN.
The headline of the CNN article, published Oct. 20, reads "Not exercising worse for your health than smoking, diabetes and heart disease, study reveals "(Not exercising worse for your health than smoking, diabetes and heart disease, study reveals).
Many of the world's public **** media reports were reprinted from this CNN article, including the Globe's source, the French health magazine TOPSANTE.
With the author's intent being to emphasize that exercise reduces mortality and allows people to live longer by enhancing CRF.
But by replacing low CRF directly with | "sedentary", it is clear that a serious logical error has been made, greatly exaggerating the health risks of sedentary behavior.