Lack of sleep nearly triples risk of gestational diabetes

Pregnant women who got less than 6.25 hours of sleep each night were 70 percent more likely to develop gestational diabetes than others, according to a new meta-analysis of two sets of studies.

The pregnancy-related form of diabetes is marked by elevated blood sugar levels.

It can lead to higher birth weights and can put both mother and baby at higher risk to develop type 2 diabetes and obesity later in life.

The University of Illinois at Chicago study adds to a body of research linking insufficient sleep – which is more common among women, than men, and especially common in pregnant women – to other complications like postpartum depression.

Pregnant women may need slightly more sleep than the seven hours recommended for adults. A new study links not getting enough sleep to an increased chance of gestational diabetes

Gestational diabetes is common among pregnant women, but rarely comes with any symptoms besides high blood sugar, only detectable with a blood sugar test.

The condition typically subsides once a woman gives birth, but puts both she and her baby at an elevated risk of developing type 2 diabetes and obesity.

The University of Illinois at Chicago (UIL) researchers did a meta-analysis of two kinds of studies. The first set included more than 17,000 participants who reported how many hours of sleep they got each night. The second set of studies had a total of nearly 300 participants, whose sleep was measured both by survey and by accelerometers.

Causes and effects of gestational diabetes 

Gestational diabetes occurs when an expectant mother’s cells struggle to process  glucose. 

This causes her to have high blood sugar and exposes her baby to elevated levels of glucose. 

There are usually no symptoms of gestational diabetes, except the mother’s high blood sugar, detectable only through a blood test.  

Babies of mothers with gestational diabetes may have higher weights than normal, making delivery more difficult.

Gestational diabetes usually subsides after the baby is born, but elevates the risk that both mother and baby will develop type 2 diabetes later in life. 

The condition is also a risk factor for obesity later in the lives of both mother and child. 

Study co-author Dr Sirimon Reutrakul says that ‘pregnant women definitely have disturbed sleep,’ but it can be difficult to tell exactly how much sleep they need.

According to data from the Centers for Disease Control and Prevention (CDC), about 35 percent of adults in the US get less than the recommended seven hours of sleep each night.

Pregnant women may need a few extra hours, or feel the need to nap more often, though the exact recommended number of hours of sleep is difficult to pinpoint. 

Dr Reutrakul says that ‘it’s complicated in pregnancy, because hormones change and [women] might be tired for other reasons; it gets mixed into other symptoms of being pregnant.’

Science hasn’t explained exactly what it is that sleep does for us, but we know that without it, our bodies are worse at just about everything. Some effects of insufficient sleep make common sense, like trouble focusing or memory issues.

But its links to chronic illnesses like diabetes are less obvious.

Our bodies generate hormones that relate to appetite control and metabolism during sleep. 

When we don’t get enough sleep, our bodies secrete less of a hormone called leptin that signals us that we are sated after eating. At the same time, levels of ghrelin increase with less sleep, making us crave sweets that deliver energy quickly.

This relatively well-understood relationship between appetite and sleep helps to explain the links between sleep and both obesity and diabetes.

The UIL study did not examine the causes for the increased likelihood of gestational diabetes among women, but the mechanism may be similar.

Dr Reutrakul and her team found that women who developed gestational diabetes were seven times more likely to later develop type 2 diabetes than others, even after adjustment for other risk factors like obesity.

Gestational diabetes elevates the risk of type 2 diabetes later in the lives of the infants too, though the study was not able to analyse by how much.

 But gestational diabetes can lead to larger babies, and delivering them can pose health risks to both the baby and the mother.

Babies of mothers with gestational diabetes also may have low blood sugar after birth. ‘In the longer term, we believe the exposure to glucose in utero can lead to metabolic problems later,’ says Dr Reutrakul.

She cautions that ‘people sometimes don’t think about sleep a lot, but [pregnant women] should be aware that this might be an additional player’ in their own health and the health of their babies, ‘and make sure they sleep enough for what their body needs.’