Too much sleep linked to a greater risk of disease and death, study finds

The recommended amount of sleep for adults is six to eight hours a night. Sleeping more than those hours is associated with an increased risk of death and ca...

Posted: Dec 5, 2018 6:47 AM

The recommended amount of sleep for adults is six to eight hours a night. Sleeping more than those hours is associated with an increased risk of death and cardiovascular diseases, says a global study published Wednesday in the European Heart Journal.

Looking at data from 21 countries, across seven regions, the research team found that people sleeping more than the recommended upper limit of eight hours increased their risk of major cardiovascular events, like stroke or heart failure, as well as death by up to 41%.

But a possible reason for this could be that people have underlying conditions causing them to sleep longer, which in turn could raise the risk of cardiovascular disease or mortality, explain the authors of the study.

The team, led by Chuangshi Wang, a Ph.D. student at McMaster and Peking Union Medical College in China, also identified a rising risk among daytime nappers.

"Daytime napping was associated with increased risks of major cardiovascular events and deaths in those with [more than] six hours of nighttime sleep but not in those sleeping [less than] 6 hours a night," Wang said.

In those who underslept, "a daytime nap seemed to compensate for the lack of sleep at night and to mitigate the risks," Wang explained.

Previous studies into this topic were mainly carried out in North America, Europe and Japan. The new study brings a global picture.

But the findings are observational, meaning the cause of this association remains unknown.

"Even though the findings were very interesting they don't prove cause and effect," said Julie Ward, a senior cardiac nurse at the British Heart Foundation, who was not involved in the study.

Having less sleep -- under six hours -- was also shown to increase these risks by 9%, compared with people who slept for the recommended six to eight hours, but this finding was not considered to be statistically significant by the team.

In 2014, 35.2% of American adults reported not getting enough sleep with less than seven hours per night, according to the CDC.

Signs in your sleep

The study asked 116,632 adults between the age of 35 and 70 from 21 countries about their sleeping habits. Participants were then followed up over an average of 7.8 years.

The team found that for every 1,000 people sleeping the recommended six to eight hours per night, 7.8 developed cardiovascular disease or died each year. This rose to 9.4 in people who slept six or fewer hours a night.

Francesco Cappuccio, professor of cardiovascular medicine and epidemiology at Warwick University, who was not involved in this study, has done several studies into sleep and its effect on our health. He says that a lack of sleep is "definitely associated with an increased risk of death."

"If you sleep less for a long time you are more prone to develop chronic disease," Cappuccio said, adding that short sleep duration has been shown to increase high blood pressure, obesity and diabetes.

However, the findings for those who underslept were not found to be statistically significant, and the greatest risk was instead seen among those who overslept.

For those sleeping eight to nine hours, 8.4 per 1,000 people developed cardiovascular disease or died each year. This rose even further in those sleeping nine to 10 hours (10.4 per 1,000) and again among those sleeping more than 10 hours (14.8 per 1,000).

This equates to an increase in risk of a 5%, 17% and 41%, respectively, compared with people who slept the recommended amount of hours.

But Wang pointed out that too much sleep could be a marker for other causes of cardiovascular diseases and death.

Do you get enough sleep?

Cappuccio agreed, adding that "it's not that long sleep causes death or ill health" but that ill health will cause you to sleep more.

Cappuccio mentioned that people who have an undetected illness may suffer from an extension of sleep. If someone has an underlying cancer, for example, they will be more fatigued and debilitated and will tend to sleep longer.

The study's main takeaway is that the optimal duration of estimated sleep is six to eight hours per day for adults, Wang explained.

It is "very important to point out that there are some very simple things you can do to help you sleep better at night," Ward said, advising people to avoid caffeine in the afternoon or evenings, as well as alcohol and nicotine, which can disrupt sleep patterns. Exercise and a balanced diet can help, she added.

'Napping could reflect underlying ill-health'

Daytime napping was found to be common in the Middle East, China, Southeast Asia and South America and was associated with higher risks of death or cardiovascular problems in those who also got the recommended hours of sleep at night or more.

But, this was not the case for people who slept under six hours per night.

"In these individuals, a daytime nap seemed to compensate for the lack of sleep at night and to mitigate the risks," Wang said.

But for those who slept enough at night, "daytime napping was associated with increased risks of major cardiovascular events and deaths," she said.

Cappuccio has previously conducted research into daily napping among British adults.

"Napping could reflect underlying ill-health (fatigue, tiredness) eventually leading to morbidity and mortality, could be a proxy for sleep deprivation, as a compensatory catch-up mechanism, or could also be a symptom of circadian misalignment," he said.

Monitoring sleeping patterns

The study had several limitations, Wang pointed out, as participants were asked to self-report their sleeping patterns and the sleep duration was based on the space between going to bed and waking up.

The team also did not collect data on sleep disorders, such as insomnia, which could have an impact on sleep and also affect health, the paper states.

Wang explained that it is usually not feasible to accurately measure sleep time in large population studies.

The researchers hope that their results will encourage doctors to ask their patients about sleeping patterns when discussing general lifestyle factors, to identify any potential underlying health problems.

Salim Yusuf, professor of medicine at McMaster University and the principal investigator of the PURE study, from which the participants were chosen, said, "For doctors, including questions about the duration of sleep and daytime naps in the clinical histories of your patients may be helpful in identifying people at high risk of heart and blood vessel problems or death."

Indiana Coronavirus Cases

Data is updated nightly.

Cases: 750432

Reported Deaths: 13764
CountyCasesDeaths
Marion1031991782
Lake556411007
Allen41662691
St. Joseph36974564
Hamilton36561417
Elkhart29390459
Tippecanoe22886225
Vanderburgh22549400
Porter19348325
Johnson18432388
Hendricks17608317
Clark13206193
Madison13139344
Vigo12608253
LaPorte12415221
Monroe12188175
Delaware10954198
Howard10285225
Kosciusko9619119
Hancock8562145
Bartholomew8164157
Warrick7856156
Floyd7781180
Grant7232179
Wayne7160201
Boone6939103
Morgan6746141
Dubois6214118
Marshall6208116
Cass6000109
Dearborn589578
Henry5895109
Noble580787
Jackson508975
Shelby500896
Lawrence4738122
Gibson444593
Clinton441455
Harrison441073
DeKalb439485
Montgomery436390
Whitley406343
Huntington402481
Steuben399759
Miami393169
Jasper387454
Knox375890
Putnam372160
Wabash360683
Ripley346970
Adams345355
Jefferson335785
White331553
Daviess3033100
Wells295181
Decatur289992
Greene286885
Fayette284864
Posey273835
LaGrange273072
Scott270156
Clay266448
Washington245234
Randolph244783
Jennings235349
Spencer234431
Starke227958
Fountain220348
Sullivan214343
Owen211658
Fulton202142
Jay200932
Carroll193420
Orange188155
Perry187137
Rush175826
Vermillion174644
Franklin170335
Tipton166146
Parke149316
Pike138234
Blackford136232
Pulaski120547
Newton113736
Brown104043
Crawford102316
Benton101414
Martin91615
Warren83815
Switzerland8118
Union72810
Ohio57811
Unassigned0420

Ohio Coronavirus Cases

Data is updated nightly.

Cases: 1108146

Reported Deaths: 20122
CountyCasesDeaths
Franklin1286421460
Cuyahoga1157382208
Hamilton813551248
Montgomery525311041
Summit48395999
Lucas43343818
Butler38951604
Stark33318929
Lorain25658504
Warren24580303
Mahoning22355603
Lake21166387
Clermont20111253
Delaware18841135
Licking16660222
Fairfield16570204
Trumbull16537482
Medina15603271
Greene15272247
Clark14233306
Wood13287198
Portage13242214
Allen11910239
Richland11601211
Miami10843224
Wayne9130222
Columbiana9029230
Muskingum8906135
Pickaway8658122
Tuscarawas8643248
Marion8641138
Erie8056164
Ashtabula7147179
Hancock6996132
Ross6943161
Geauga6834150
Scioto6534105
Belmont6155174
Union584549
Lawrence5726102
Jefferson5675158
Huron5544122
Sandusky5439125
Darke5415129
Seneca5347126
Washington5318109
Athens523660
Auglaize501887
Mercer487385
Shelby476595
Knox4570112
Madison444065
Ashland435597
Putnam4336103
Defiance432298
Fulton432072
Crawford4036110
Brown402461
Logan387577
Preble3848104
Clinton379166
Ottawa373581
Highland359665
Williams348078
Champaign344258
Guernsey324853
Jackson318154
Perry297350
Morrow291840
Fayette285450
Hardin274965
Henry273367
Holmes2699101
Coshocton268960
Van Wert247264
Adams243156
Pike242835
Gallia240750
Wyandot234556
Hocking220162
Carroll197148
Paulding176542
Meigs148240
Monroe136344
Noble136039
Harrison114138
Morgan109624
Vinton85517
Unassigned03
Fort Wayne
Partly Cloudy
66° wxIcon
Hi: 90° Lo: 65°
Feels Like: 66°
Angola
Partly Cloudy
° wxIcon
Hi: 85° Lo: 63°
Feels Like: °
Huntington
Partly Cloudy
67° wxIcon
Hi: 90° Lo: 66°
Feels Like: 67°
Decatur
Partly Cloudy
66° wxIcon
Hi: 91° Lo: 67°
Feels Like: 66°
Van Wert
Partly Cloudy
66° wxIcon
Hi: 91° Lo: 64°
Feels Like: 66°
Our next system brings us the potential for strong to severe thunderstorms on Friday.
WFFT Radar
WFFT Temperatures
WFFT National

Community Events