Poor grip strength is associated with an increased risk of dying prematurely and, to a lesser extent, with a increased risk of having a heart attack or stroke, according to a new, large international study.
In
fact, the study found that grip-strength test results were a stronger
predictor of death from any cause (but not of heart attack or stroke)
than systolic blood pressure readings.
The study, which was led by researchers at McMaster University in Ontario, Canada, was published this week in the journal The Lancet.
Global data
For
the study, researchers tested the grip strength of about 140,000 people
aged 35 to 70 across 17 low-, medium- and high-income countries, and
then followed them for an average of four years. After adjusting for a
variety of factors (such as age, education level, physical activity
level, and tobacco use), the researchers found that every 5-kg decrease
in grip strength was associated with a 16 percent increase in death from
all causes, a 17 percent increase in death from heart disease, a 17
percent increase in death from an illness not related to heart
disease (such as cancer), a 7 percent increase in the risk of a heart
attack and a 9 percent increase in the risk of stroke.
Grip
strength was not associated with diabetes, bone fractures, fall-related
injuries or admission to a hospital for pneumonia or chronic
obstructive pulmonary diseases (COPD).
As a
result of these findings — and previous research linking weakened muscle
strength with early death — the study’s authors suggest that grip
strength might prove to be an easy and inexpensive screening tool for
physicians to use to identify people at high risk of death after
developing a major illness.
Caveats and limitations
But don’t expect your physician to be asking you to squeeze a handgrip dynamometer
at your next office visit. As the study’s authors point out, “The
observational nature of this study does not allow us to make strong
conclusions on the causal role of muscular strength in death or
cardiovascular disease.”
In other words, the
findings may be interesting, but they are not conclusive. Here’s how the
experts who reviewed the study for the “Behind the Headlines” website
of the United Kingdom’s National Health Service (NHS) put it:
What we don't know from the study is why and how muscle strength is linked to the chances of death. It might seem obvious that people who are weak and frail are more at risk of death than other people, but we don't know whether this is because they are already ill, or whether their weak muscle strength makes them more vulnerable to getting ill, or less able to survive illness if they do get sick.Importantly, the study doesn't tell us what can be done for people with low muscle strength. Should we all be doing weight training to increase our strength, or would that make no difference? Low muscle strength may reflect lots of things, such as the amount of exercise people do, what type of diet they eat, their age and occupation. We know that muscle strength declines as we age, but we don't know the effect of trying to halt this decline.Should doctors routinely measure people's grip strength to test their health? The researchers say it is a better predictor of cardiovascular death than blood pressure, and could be easily used in lower-income countries. But raised blood pressure and cholesterol both increase the risk of cardiovascular disease, and there are treatments available to get them under control. Simply measuring a person’s grip strength would miss this opportunity and not lead to any preventive strategies.
“It
is unlikely that a ‘grip test’ would replace standard protocols for
diagnosing cardiovascular diseases, which rely on a combination of risk
assessment methods and tests, such as electrocardiogram (ECG) and a coronary angiography,”
the NHS reviewers conclude. “However, such a test could be useful in
areas of the world where access to medical resources is limited.”
