Australian researchers have found a link between poor hand grip strength and hypoxemia – low levels of oxygen in the blood.
The experts assessed middle-aged to elderly men on their hand grip strength and blood oxygen saturation, whilst measuring fat and body mass and adjusting for lifestyle information, such as diet, smoking status and physical activity.
They found a link between low levels of oxygen saturation in the blood and a weaker grip strength, regardless of whether their muscle mass was high or low.
The experts suggest that a low grip could be a telltale sign of hypoxemia, which an interfere with heart and brain function by failing to deliver enough oxygen to the organs.
No matter how much muscle mass, a poor grip can highlight underlying issues connected with hypoxemia (lack of oxygen in the blood)
'My study, whilst examining grip strength, does not show that people are likely to suffer poor health in later life and die early (although there are several studies which do show that),' study author Dr David Stevens at Flinders University in Adelaide, South Australia told MailOnline.
'Rather, my study shows that, regardless of a male’s muscle mass, worsening hypoxemia is associated with reduced grip strength.'
Reduced hand grip strength is already associated with increased severity of a range of chronic conditions, including cardiometabolic disease and chronic obstructive pulmonary disease.
Hand grip measurement for the study was measured using the Smedley analogue hand dynamometer (pictured)
For this new study, researchers had originally aimed to determine associations between hand grip strength, muscle mass, fat mass and obstructive sleep apnea (OSA).
OSA, an interruption to breathing during sleep, is a potentially serious sleep disorder, and itself can go on to cause hypoxemia by limiting oxygen intake.
Researchers assessed 613 men aged between 40 to 88 years in the Men, Androgen, Inflammation, Lifestyle, Environment, and Stress (MAILES), a long-term sample that's been running since 2009 to analyse cardio-metabolic disease risk in men.
They used a Smedley analogue hand dynamometer – a small handheld device with a dial – to measure the participants' grip strength.
The experts also used a special type of X-ray called dual X-ray absorptiometry to determine whole body muscle mass and fat mass.
Researchers found that reduced grip strength was associated with lower oxygen nadir − the lowest oxygen saturation a patient drops to − and a greater time spent below 90 per cent oxygen saturation.
Professor Robert Adams at Flinders University, says no matter how much muscle mass, a simple grip test can highlight underlying issues connected with ageing and worsening hypoxemia.
'Without good levels of oxygen in the blood, we cannot use the muscles we have to their maximum,' he said.
Dr Stevens admitted that the fact all participants were male is an is 'an inherent limitation' of the study, and means the results may not be generalised to women.
HYPOXEMIA: DEFINITION AND CAUSES
Hypoxemia is a below-normal level of oxygen in your blood, specifically in the arteries.
Hypoxemia is a sign of a problem related to breathing or circulation, and may result in various symptoms, such as shortness of breath.
It's determined by measuring the oxygen level in a blood sample taken from an artery (arterial blood gas).
It can also be estimated by measuring the oxygen saturation of your blood using a pulse oximeter - a small device that clips to your finger.
Several factors are needed to continuously supply the cells and tissues in your body with oxygen:
- There must be enough oxygen in the air you are breathing.
- Your lungs must be able to inhale the oxygen-containing air and exhale carbon dioxide.
- Your bloodstream must be able to circulate blood to your lungs, take up the oxygen and carry it throughout your body.
A problem with any of these factors - for example, high altitude, asthma or heart disease - might result in hypoxemia, particularly under more extreme conditions, such as exercise or illness.
When your blood oxygen falls below a certain level, you might experience shortness of breath, headache, and confusion or restlessness.
Common causes of hypoxemia include:
- ARDS (Acute respiratory distress syndrome)
- Asthma Congenital heart defects in children and adults
- COPD (chronic obstructive pulmonary disease) exacerbation — worsening of symptoms
- Interstitial lung disease
- Medications, such as certain narcotics and anesthetics, that depress breathing
- Pneumothorax (collapsed lung)
- Pulmonary edema (excess fluid in the lungs)
- Pulmonary embolism (blood clot in an artery in the lung)
- Pulmonary fibrosis (scarred and damaged lungs)
- Sleep apnea
Source: Mayo Clinic