In Resistant Hypertension, Sleep Apnea Results in Greater Blood Pressure and Treatment Lowers It.

Published on April 6, 2015

A new meta-analysis published in the Journal of Hypertension suggests that untreated sleep apnea may be a major factor in why medications appear to be less effective in reducing high blood pressure in some people. Further, the study shows that CPAP therapy may be the key to helping those with difficult to treat hypertension get their blood pressure under control.

As many as 10 million people in the United States have “resistant hypertension” which either doesn’t respond to or requires multi-drug therapy. Most people with resistant hypertension also have obstructive sleep apnea (OSA). It’s a deadly combination that exponentially increases the risk of death or disability from a stroke or heart attack, but one that researchers say may have a relatively simple solution.

“Our study indicated that the patients with resistant hypertension and the very highest blood pressure experienced the greatest reduction in blood pressure after using CPAP therapy,” says Ulysses Magalang, MD, the study’s principal investigator and director of the Sleep Disorders Center at The Ohio State University Wexner Medical Center, in a release. “This response suggests that untreated sleep apnea may be why these people haven’t seen improvement in their blood pressure despite the concurrent use of three or four medications.”

Previous studies have shown that CPAP therapy offers patients with hypertension a significant, yet modest two to three point reduction in blood pressure. Magalang and the research team found that when they honed in on the specific results for those with resistant hypertension, the benefits of CPAP use looked quite different.
In their study, patients experienced an average reduction of 7.21 millimeters of mercury (mmHg) in ambulatory systolic blood pressure (SBP), and 4.99mmHg in ambulatory diastolic blood pressure (DBP) from baseline after using CPAP therapy. Ambulatory blood pressure (measured over a 24 hour period) is considered a good predictor of future organ damage and cardiovascular problems.

“We know that small changes in blood pressure translate into big benefits in terms of protecting the heart and reducing stroke risk,” says co-author Christopher Valentine, MD, a nephrologist at Ohio State’s Wexner Medical Center. “These findings suggest that physicians may need to be more aggressive with screening for sleep apnea and ensuring CPAP therapy compliance in patients with resistant hypertension.”

Systematic Analysis of Resistant Hypertension and CPAP Use

Despite the fact that millions of people suffer from resistant hypertension, and that its cardiac comorbidities carry a significant public health burden, studies looking at CPAP use and hypertension historically haven’t focused on this difficult to treat population.

“We have a lot of evidence about the benefits of CPAP in people with hypertension and OSA, but ours is the first analysis to systematically review CPAP use in people with difficult to treat hypertension and apnea,” Valentine says. “The results are clinically relevant because the effects that we found are significantly higher than what’s been previously observed in a more general hypertensive population. CPAP use could offer this subset of patients a new chance to reach a healthier blood pressure goal, or even to reduce their medication burden.”

From an initial scan of 157 articles, the researchers narrowed the data from 6 different studies, looking at pre- and post-CPAP blood pressure measurements from more than 300 patients with resistant hypertension. The duration of CPAP use ranged from 3 weeks to 6 months. In addition to measuring ambulatory blood pressure, investigators also looked at CPAP therapy and its impact on nighttime blood pressure—another predictor of future cardiac events.

While the researchers found significant improvement in ambulatory and nocturnal blood pressure measurements after CPAP use in some of the studies, other cuts of the data showed that CPAP therapy delivered about the same nocturnal blood pressure benefit as observed in previous studies.

“More studies are needed to further define CPAP influence on blood pressure, but overall, we think that the longer the CPAP is used during the night, the greater the impact,” Magalan says.

The authors also acknowledge other limitations of their analysis, including small sample size, and potentially confounding factors such as the concomitant use of the antihypertensive medications, obesity, and other life-style factors such as the use of alcohol and smoking.

Sleep Apnea, High Blood Pressure: Shared Genetic Origins?

Magalang and Valentine say their findings also support the idea that resistant hypertension and OSA represent an “extreme phenotype” of those who have OSA, but never develop hypertension. A phenotype describes how an individual’s characteristics are influenced by the interaction of their genes with their environment. The researchers further suggest that resistant hypertension in those with sleep apnea may be caused by a less common gene variant that nonetheless has significant impact.

It’s a hypothesis that will likely be put to the test over the next decade. The researchers who collaborated on the paper all belong to the Sleep Apnea Genetics International Consortium (SAGIC), a partnership of scientists from five continents who are building the first-ever international biomedical database to uncover the genetic causes of sleep apnea. By collecting biological material from thousands of patients with sleep disorders, the group hopes to amass enough data to start identifying underlying genetic causes of different conditions.

“We’re only just now beginning to appreciate the link between sleep apnea and disease,” says Magalang. “We hope that one day we will find common genes shared between people who have uncontrollable blood pressure and sleep apnea, and that will open up a whole new world of interventions and treatment strategies.”

The research was supported by the National Heart, Lung and Blood Institute. Ohio State’s Center for Clinical and Translational Science (CCTS) also provided biomedical informatics support for the study and provides ongoing informatics support for SAGIC.

6 Things That Are Keeping You Fat.

K. Aleisha Fetters, U.S. News & World Report
MARCH 30, 2015  11:23 AM

You're filling up on healthy foods, exercising daily and still, the scale isn't budging. It's mind-numbingly frustrating. Luckily, it's also fixable. Here are six common things that could be standing between you and your weight-loss goals – plus easy ways to bust through each.


1. You Aren't Tracking What You Eat

"Most of the time, when someone comes into my office saying they aren't losing weight, the problem is that they are eating a lot more than they think they are," says Holly Herrington, a registered dietitian and clinical nutritionist with the Center for Lifestyle Medicine at Northwestern Medical Faculty Foundation. "Almost every single person underestimates how much they are eating." You can blame oversized restaurant portions, mindless munching and "health halos" for that, she says.

After all, French fries and ice cream aren't the only things that are calorie-packed. So are healthy foods, including olive oil, avocado and nuts. For instance, 1 cup of almonds contains about 750 calories. If you're snacking on them (a great idea), but without measuring and tracking those calories (a bad idea), you could easily end up gaining weight, Herrington says.

She recommends tracking everything you eat, at least for a couple months, with apps like My FitnessPal, which will help you learn proper portion sizes and how your favorite health foods measure up calorie-wise. In one American Journal of Preventive Medicine study, people who kept daily food records lost double the weight of those who didn't track their food intake.

2. You're Not Sleeping Enough

A bad night's sleep can wreck your weight-loss efforts through a two-pronged approach. For one, it makes you hungry and likely to overeat. "When you don't get enough sleep, your levels of cortisol and also ghrelin, a hormone that increases the sensation of hunger, rise," explains board-certified internist Dr. Patricia Salber.

For example, in one University of Chicago study, healthy young men who got just four hours of sleep two nights in a row (compared to their usual seven to nine hours) reported a 24 percent increase in appetite, along with cravings for candy, cookies, chips, bread and pasta. They also experienced an 18 percent decrease in leptin, which promotes fullness, and a 28 percent increase in the hunger-hormone ghrelin.

Second of all, not getting enough sleep could make your body store what you do eat as fat. For instance, a 2011 study in the American Journal of Clinical Nutrition found that just one night's bad sleep caused healthy men's resting energy expenditure – the number of calories they burned by simply being alive – to drop by 5 percent. The number of calories they burned after each meal also dropped by 20 percent.

"Sleep deprivation and sleep apnea may affect blood sugar levels and increase insulin resistance," says endocrinologist Dr. Michael Bergman, clinical professor of medicine at the NYU Langone Medical Center. "Sleep disorders, namely obstructive sleep apnea, [have] been associated with the development of Type 2 diabetes."

If clean-sleep habits – such as keeping your bedtimes consistent and not playing on electric devices in the hour before bed – don't help you get eight solid hours a night, talk to your doctor about how you can sleep better and longer, he says.

3. You're Eating the Same Number of Calories You Did on Day One of Your Diet

Oh, the weight-loss plateau: At the beginning of your diet, you were losing weight and feeling great. But now, you're doing the exact same thing, but with zero results. That might be the problem. "As you lose weight, your caloric needs will change," Herrington says. "The smaller you get, the fewer calories your body needs, so the fewer calories you'll need to eat to continue losing weight."

If your weight-loss results have plateaued for one to two months, she recommends gradually cutting back on calories. Start by eating 100 fewer calories a day and see how the scale shifts in a couple weeks' time. Don't cut back too much, though. Most women shouldn't eat any fewer than 1,200 calories a day and men shouldn't eat any fewer that 1,700 a day. Meanwhile, you should never feel famished or low on energy, she says.

4. You're Constantly Stressed

Acute stress – say from a looming work deadline or relationship drama – can cause your appetite to go MIA. But if the stress keeps up and becomes chronic, too-high levels of the stress hormone cortisol can increase your appetite, particularly for high-carbohydrate foods, according to Salber.

"When stressed, people seek to comfort themselves and relieve the tension," she says. "All too often, that means turning to sugar or starchy foods." High-carb foods can cause a quick spike in blood sugar and feel-good serotonin levels. But both crash quickly, and put you in a vicious cycle of stress and overeating.

Meanwhile, by stimulating the production of insulin, cortisol also increases your body's tendency to store calories as visceral fat. A type of fat that hangs out in the abdominal cavity and likes to hug your vital organs, visceral fat is associated with the development of insulin resistance and, in some cases, diabetes, Salber says.

If you can't remember the last time you weren't stressed, consider visiting your doctor or a therapist to help you manage your stress levels and get healthy. Mental health issues, including stress, are no different than physical health issues, she says. They deserve professional help.

5. You're Using Artificial Sweeteners

Artificial sweeteners, whether you stir them into your coffee, get them from diet sodas or spoon them from your yogurt container, are an easy way to cut calories and sugar in the short term, but they could harm your long-term weight-loss efforts. Case in point: Research from the University of Texas found that over the course of 9.5 years, the average two-a-day diet-soda drinker puts on five times more belly fat than do people who abstain.

That could be because your brain responds to artificial sweeteners by telling you to eat more sweet stuff, according to the Harvard School of Public Health. Meanwhile, they may also throw off the balance of healthy bacteria in the gut, Salber says.

A 2014 study from the Israel-based Weizmann Institute of Science's immunology department found a significant correlation between the consumption of artificial sweeteners, gut bacterial configuration and a tendency to develop glucose intolerance, which contributes to the development of obesity and Type 2 diabetes.

Eliminate any artificial sweeteners in your diet and replace them with sweeteners that also contain vitamins and minerals, such as honey and maple syrup. Just make sure to count their calories.

6. You Have a Medical Condition

While rare, underlying health conditions can make weight-loss difficult to achieve on your own. For instance, Cushing's disease, marked by excess cortisol levels, and polycystic ovary syndrome, a common endocrine disorder in women, can both contribute to glucose disorders, Bergman says.

Meanwhile, hypothyroidism, a condition in which the thyroid gland doesn't produce enough hormones, can also contribute to weight-management issues. About half of thyroid disorder cases in America are undiagnosed, according to the American Association of Clinical Endocrinologists.

If you aren't losing weight, but feel like you are following your body's caloric needs and are exercising between two and five hours a week, Herrington recommends talking to your doctor about your weight-loss concerns. He or she may be able to run some simple tests to make sure a health condition isn't behind your frustrations. If something is amiss, treating it will do more than help you lose weight.

SDB Treatment May Reduce Hospital Admission Rates in Chronic Heart Failure Patients

Published on March 12, 2015

ResMed today announced data from two studies about sleep-disordered breathing (SDB) in chronic heart failure will be presented at the 64th Annual Scientific Sessions of the American College of Cardiology, from March 14 through 16.

“The data we are presenting are important because they point toward a connection between breathing disorders in sleep, like sleep apnea, and chronic heart failure,” says ResMed chief medical officer, Glenn Richards, MD, in a release. “We look forward to learning the results of our landmark clinical study called SERVE-HF, that examines whether addressing sleep-disordered breathing in people with chronic heart failure improves survival.”

Final data from nearly 7,000 patients in a German registry of more than 10,000 patients with stable chronic heart failure showed that SDB was present in nearly one out of two people (46%). Prevalence of SDB increased rapidly with age. Other risk factors include male gender, more severe heart failure, atrial fibrillation, and increased weight.

This data will be presented in a poster session by Olaf Oldenburg, senior cardiologist in the Department of Cardiology at the Heart and Diabetes Center North Rhine-Westphalia, Bad Oeynhausen, Germany, on March 16 from 9:45 AM to 10:30 AM. (Session 1252, Poster 212; Prevalence and Predictors of Sleep-Disordered Breathing in Patients with Stable Chronic Heart Failure: Final data of the SchlaHF Registry; Poster Hall B1)

Data from an American study suggests that treatment of SDB may reduce hospital admission rates in patients with chronic heart failure. Patients compliant with PAP therapy had significantly reduced hospital visits in the 6 months after starting therapy compared to the 6 months before therapy. A comparable group who were not compliant with PAP therapy had no change in frequency of hospital visits.

This data will be presented in a poster session by Dr Sunil Sharma, associate professor in the Department of Medicine at Thomas Jefferson University on March 14 from 3:45 PM to 4:30 PM. (Session 1145, Poster 192; Treatment of Sleep Disordered Breathing in Patients Admitted for Decompensated Heart Failure Reduces 6 Months Hospital Visits, Poster Hall B1)

New Pillows Help You Prevent Wrinkles While You Sleep

December 8, 2014 5:30 AM

NEW YORK (CBSNewYork) — We’ve all heard of getting beauty sleep, but what if getting that rest actually contributed to wrinkles? Some doctors say it all depends on how you use your pillow.

If you think a little shut-eye rejuvenates you for the day ahead, Dr. Michael Kane says think again.

“People don’t realize this, but for a third of your life, you’re laying on a pillow that is ripping and shearing the ligaments under your skin,” he told CBS2’s Alex Denis.

That means you may get sleep wrinkles.

“These diagonal wrinkles along the jaw line, the diagonal wrinkles on the forehead and even vertical wrinkles on your cheek,” Kane said.

Many women weren’t thrilled by the news.

“We’re always trying to stay young, usingbeauty products, and now you can’t even sleep peacefully,” said Debbie Siricl.

But it also affects men.“Men and woman both get sleep wrinkles depending on how they sleep on their pillows,” said Kane.

Many people choose to have filler injected to soften the look of sleep wrinkles, but there are a number of products available that say they’ll lessen the formation of wrinkles from sleep.

One option is called the JuveRest pillow.

“It does help to cradle your head so you sleep on your back, not rolling side to side,” said Kane. “If you’re a side sleeper, there’s a side pocket for your head and you’re shoulder.”

You can check out the JuveRest here and some other products by clicking here, here and here.

Sleep Apnea Linked to Poor Aerobic Fitness

Published on November 24, 2014

People with moderate to severe obstructive sleep apnea may have an intrinsic inability to burn high amounts of oxygen during strenuous aerobic exercise, according to a new study led by researchers at University of California, San Diego School of Medicine.

The study, reported in the current issue of Journal of Clinical Sleep Medicine, shows that people with sleep apnea, in which breathing repeatedly starts and stops during slumber, have a lower peak oxygen uptake during aerobic activity than those who do not suffer from the sleep disorder.

People who suffer from apnea are more likely to be obese and thus would be expected to be less fit as well. The researchers, however, found that apnea patients had a reduced aerobic fitness, even compared with those of similar body mass indices.

“Encouraging patients to exercise more is part of the story, but that is not the whole story,” says lead author Jeremy Beitler, MD, assistant clinical professor in pulmonary and critical care medicine, in a release. “We believe the sleep apnea itself causes structural changes in muscle that contributes to their difficulty exercising.”

For the study, researchers performed sleep studies of men and women with a range of apnea symptoms. The sleep studies were performed to clinically evaluate the severity of the patients’ apnea and to screen participants for sleep disorders besides apnea that could confound the study results.

Fifteen men and women with moderate to severe apnea and 19 with mild or no apnea were then asked to pedal a stationary bike at incrementally harder resistance levels–similar to what a person would experience climbing up a progressively steeper hill. The participants were directed to pedal to exhaustion.

From the exercise test results, and previous measurements of participants’ resting metabolic rates, scientists calculated each person’s VO2 max–a measure of the maximum amount of oxygen the person can uptake during strenuous exercise–and its deviance from the expected VO2 max for a person of the same age, gender, and body mass index.

After adjusting for baseline differences, scientists showed that people with sleep apnea had on average a 14% lower VO2 max than control subjects. Furthermore, the number of times a person stopped breathing, for 10 seconds or more, per hour of sleep, could predict 16% of the variability observed in the group’s peak VO2.

“This is a big discrepancy,” Beitler says.

Researchers believe that VO2 max measurements may be an early marker for those who are at higher risk of stroke and heart attack and that VO2 max measurements could motivate early interventions to treat apnea.

Poor sleep tied to inflammation in teens

Notes from Dr. Norman Blumenstock:

Teens who don’t get enough sleep may be at risk for chronic problems later in life from increased inflammation throughout the body, according to a new study.

BY KATHRYN DOYLE

Thu Nov 20, 2014 3:29pm EST

(Reuters Health) – Teens who don’t get enough sleep may be at risk for chronic problems later in life from increased inflammation throughout the body, according to a new study.

Those who didn’t get enough sleep during the week and especially those who slept longer on weekends had higher inflammation levels tied to heart disease and diabetes, researchers report in Sleep Medicine.

Investigators used blood tests to measure kids’ C-reactive protein (CRP) levels. High levels indicate that the body is in “inflammation mode,” said lead author Martica Hall of the psychiatry department at the University of Pittsburgh in Pennsylvania.

“Frankly, high CRP over a long period of time is bad for everything,” Hall said. “We say it increases the risk of ‘all things bad.’”

This study only measured CRP levels at one point in time, but “folks that have chronically high CRP are at risk for heart disease and diabetes,” Hall told Reuters Health by phone. “For adults we know that short sleep is associated with CRP levels.”

The researchers also had the 244 healthy high school students wear wrist monitors that recorded how much they slept.

Most kids had CRP levels in the low to moderate risk range, below 3 milligrams per liter, but 33 students qualified as “high risk” by scoring above that threshold.

On average, the kids got less than six hours of sleep per night during weekdays and between seven and eight hours on the weekends.

Teens who slept the least during the week were most likely to be in the high-risk group. Additionally, those who slept at least two hours longer on the weekends were more than twice as likely to be in the high-risk group, compared to those who had more consistent sleep times throughout the week.

Kids in the high-risk group also tended to have a higher body mass index, which is a measure of weight in relation to height.

Sleep duration was still linked to CRP levels even when the authors accounted for depression, sex, race, parental education and body mass index, which is usually an important predictor of CRP levels, Hall said.

“The kids who have a big discrepancy between the amount of sleep they get between weekdays and weekends, as well as those who have short sleep during the school day, that’s associated with higher level of CRP,” Hall said.

Similar results have been seen in adults and the elderly, but these studies that look at one moment in time can’t prove cause and effect, Dr. Francesco Cappuccio told Reuters Health in an email.

“In other words, is sleep deprivation causing an activation of inflammation or is an underlying reason for raised inflammatory markers the cause of reduced sleep?” said Cappuccio, a cardiovascular physician at the University of Warwick in Coventry, U.K. who was not involved with the new study.

Caution is always a good approach for results like these, but there are plenty of reasons for believing that sleep deprivation could be harmful, he said.

CRP levels can be lowered, but it would take a separate experiment to determine if changing sleep patterns would effect that change, Hall said.

“The cool thing about sleep is that it’s changeable,” she added.

Hall said kids and parents should focus on lengthening sleep times during the school week and not worry so much about the weekend. Other studies have found that highly variable sleep lengths are associated with health risks, so standardizing and lengthening sleep for five of the seven days of the week is a good start, she said.

“One of the reasons why there is such a move for trying to change high school start times is this is a population which is biologically predisposed to be awake at night,” Hall said.

In August, the American Academy of Pediatrics recommended schools delay start times to at least 8:30 a.m. to improve the physical and mental health of students (see Reuters Health story of August 25, 2014 here: reut.rs/1F7MWwc).

“They are predisposed to be awake at night then have really early start times, and that may increase the risk for way downstream disease,” she said.

Sleep sensors: waking up to the need to study our night's rest

Notes from Dr. Norman Blumenstock

Many people are turning to fitness trackers to help boost the health benefits of better sleep

Sales of sleep tracking devices are booming as more people become mindful of their health. Big manufacturers are piling in, but do the gadgets work, and, if so – how? Photograph: Vincent Besnault/Getty Images

Every night Jack Hammond straps a small gadget to his wrist. The sensor claims to track his sleep, monitoring every toss and turn so that when he wakes it can tell him how long he slept, how much of it was deep sleep – and how often he was woken up by his unsociable neighbor.

"I can see that I need about four hours' deep sleep to feel refreshed, and I need to be asleep for about eight hours for that to happen," says Hammond, a 36-year-old plumber from Northhampton. "I can also see that when I've had caffeine too late I get less deep sleep."

Hammond's gadget is a fitness tracker – a small bracelet device that by day can measure his activity and calorie burn, the distance he has walked and altitude climbed, and reveal how long he spends at his desk. Part of the "quantified self" movement, more than 3.8m fitness trackers like Hammond's were sold worldwide in 2013, predicted to rise to 14.6m by the end of 2014, according to the analysts CCS Insight.

"Several devices have supported sleep measurement for some time, from smaller companies such as Jawbone, Fitbit and Basis," said Ben Wood, the head of research at CCS Insight. "The big players are now getting in on the action and Sony and Samsung devices support sleep tracking too."

But do the devices work? Does using them do you any good?

Sleep has always been considered scientifically important to all-round physical health. But efficacy of fitness trackers to measure and improve sleep is less established.

Studies have found that people who sleep for less than six hours a night have a risk of high blood pressure three times greater than those who get more than six hours, and that women who sleep less than four hours a night are twice as likely to die from heart disease as those who sleep longer. Other research suggests that a lack of quality sleep is linked to the onset of diabetes, obesity and cancer, not to mention deterioration of mental health and memory. Conversely, sleeping too long has also been shown to cause issues. The recommended amount is between seven and nine hours.

"There's physical restoration component to sleep, including healing, as well as mental restoration component," explains Dr Michael Breus, a US "sleep doctor", based in Scottsdale, Arizona. "During REM [rapid eye movement] sleep in particular there's a cleaning process to get the trash out of there, and a strengthening process that occurs for the more important memories," said Breus.

"Anything that allows you to wake up feeling refreshed in the morning is what you should be aiming for, which is generally between six and nine hours," explained Dr Irshaad Ebrahim from the London Sleep Centre. "But it's not all about time, it's about the quality of the sleep, whether you complete sleep cycles."

As to using motion trackers to measure sleep, he said: "They're not measuring sleep, simply motion – not muscle tone, brain waves, heart rate or eye movement. You cannot infer quality of sleep from motion and tell what is crucial REM [rapid eye movement] sleep and what is not. People can become obsessed about their sleep through these gadgets doing them a disservice, worrying about it and in turn getting less decent sleep and having a negative impact."

Breus is less concerned. "They pique people's curiosity, and it gets them to ask 'how is my sleep'? That's the best thing about them. I wouldn't say they are dangerous, but it's a garbage-in, garbage-out situation, and it's impossible to make recommendations without good data."

For some users, that curiosity can lead them to understand how to sleep better. "My Fitbit told me I slept for more hours than I thought I did," said James Stockton, 29 from Southampton. "It was quite encouraging, and I could see patterns in my sleep when I exercised more or drank alcohol."

If, however, inspired by a sleep gadget, you want to find out general tips for better sleep, you will discover the advice doesn't fit so well with a modern lifestyle. Screens on smartphones, tablets and TVs emit blue light that disrupts the natural process of falling asleep – and is best avoided for an hour before going to bed. Avoiding alcohol and caffeine raises the quality of sleep, as does getting regular exercise.

Motion trackers aren't the only gadgets claiming to track sleep. Products such as the SleepRate, which comes with a chest strap, will track heart rate, which can be used to infer sleep. Although more accurate than motion trackers, they still cannot conclusively monitor all stages of sleep and reveal the crucial quality of a period of sleep.

"I get patients showing me their sleep data on smartphones," said Breus. "But I can't tell them what I don't know. The data isn't good enough to give them a diagnosis. They could be useful for tracking sleep trends over a longer period of time, to see when something changes, though."

Most of the devices currently available to consumers simply track motion to infer sleep. Sleep therapists use much more sophisticated machines that monitor brain waves, muscle tone and eye movement to directly detect the different phases of light and deep sleep.

The next wave of sleep gadgets, expected to hit the market within six months, is likely to include more sophisticated sleep-trackers that can monitor brain wave activity and eventually other biometric indicators, such as heart rate, muscle tone, eye movement and breathing rate.

Brain wave patterns are thought to be the best indicator at present. "We expect this to become a standard feature in most wearable devices , both fitness bands and smart watches, from now on," said Wood.

In the meantime, many sleep-tracking devices are built into tools for tracking more general fitness – and there is evidence that consumers are losing enthusiasm. A third of owners abandon their fitness tracker within six months, according to research from Endeavour Partners.

"I used to track my sleep with my Flex, but I gave up in the end," said Jessica Ross, 22, from Liverpool. "It was boring and didn't really tell me anything to keep me wearing it either at night or through the day. It lasted four months and then went in a drawer."

Top trackers

There are many devices on the market that claim to track your sleep, some better than others.

Here are six of the best available at the moment.

Misfit Shine – £80 A small metal waterproof disc, the Misfit Shine is one of the smallest and most comfortable to wear. It automatically detects deep and light sleep and awake moments via movement. It has a four-month battery life and outputs the data via Bluetooth to an Android or iPhone app.

SleepRate – £60 Combining a chest heart rate monitor with a smartphone app, SleepRate, which uses a heart rate strap, monitors sleep and can craft a bespoke sleep improvement plan. SleepRate claims to be more accurate than motion-based sleep monitors and if serious problems are detected SleepRate will suggest a visit to a sleep doctor.

Jawbone UP24 – £125 This fitness band can monitor light and deep sleep and waking periods using movement while automatically connecting to an iPhone or Android smartphone via Bluetooth. It will also wake up the wearer with a small vibrating alarm at the optimum time for a maximum refreshed feel.

Fitbit One – £80 Fitbit's pedometer-style fitness tracker can also monitor sleep, slipped into a small soft band worn around the wrist. Like the others it detects movement and can wake the user through a small vibrating alarm.

Fitbit Flex – £80 The Flex is essentially the Fitbit One formed into a bracelet, detecting sleep through moment and connecting to the Fitbit iPhone, Android and Windows Phone app via Bluetooth.

Withings Pulse O2 – £100 The Pulse will track sleep via movement, giving readings on total sleep and sleep cycles, slipping into a bracelet worn around the wrist. It connects via Bluetooth to an iPhone or Android app to display the data.

12 Foods That Sabotage Sleep

Notes from Dr. Norman Blumenstock
Remember not to go to sleep on a "full stomach".

It's recommended that you have at least 3 hours after eating before you go to sleep in order to avoid any negative issues.

Sleep Better

The foods you eat for dinner or shortly before bed can prevent you from getting some much-needed zzz's. Here's what to shun for up to several hours before turning in if you want to sleep better and wake rested — from tomatoes and chocolate to cheddar cheese.

Celery

Steer clear of celery just before bed. Celery and other foods with a high water content (cucumbers, watermelon, radishes and such) are natural diuretics that may cause you to wake in the middle of the night with a full bladder.

Tomatoes

Tomatoes are rich in tyramine, an amino acid that triggers the brain to release norepinephrine, a stimulant that boosts brain activity and delays sleep. Other tyramine-rich foods include eggplant, soy sauce, red wine and aged cheeses, such as brie and Stilton.

Cheese Pizza

Foods high in fat and fried foods take longer to digest and can cause discomfort that interferes with sleep. They can also reduce the effectiveness of some medications taken at night, says Alon Avidan, a neurologist and director of UCLA's David Geffen School of Medicine Sleep Disorders Center.

Alcohol

Although a nightcap or a glass of wine before bed may help you doze off quicker, it disrupts sleep later in the night and robs you of rapid eye movement (REM) sleep. Lack of REM sleep harms concentration, memory and motor skills.

Black-bean chili

This dish could be a disaster if you eat it close to bedtime. The body has a hard time digesting beans, so stomach-rumbling gas pains will keep you from a good night's sleep, says Helen Rasmussen, a research nutritionist at Tufts University.

Dark chocolate

A small piece of dark chocolate each day helps keep your heart healthy — but don't nibble it right before you go to bed. Dark chocolate (though not white chocolate), hot cocoa and tea all contain caffeine, and if you're caffeine-sensitive, you may find yourself staring at the ceiling instead of sleeping.

Gumdrops

A handful of gumdrops (or any candy) may cause your blood sugar levels to spike and then fall rapidly as the body releases insulin to bring them under control. You may fall asleep easily, but these fluctuations make it difficult to stay asleep.

Tacos

A taco liberally sprinkled with hot sauce may set your taste buds tingling, but eating it within a few hours of lights-out can set you up for a bad case of heartburn and a restless night. Ditto for other spicy foods.

Steak

Save the leftover slice of steak for lunch tomorrow. Foods high in protein and marbled fats, such as steak and roast beef, are slow to digest. If your body is busy digesting food, there's more of a chance that you'll have a restless night.

Carbonated soft drinks

Caffeine, that sneak thief of sleep, can turn up in unexpected places, including root beer and lemon-lime soda. Added to a food or beverage, caffeine must be listed as an ingredient; if it occurs naturally (coffee, tea, chocolate), it doesn't. Check the label.

Dagwood sandwich

A heavy meal just before bed can rob you of the shut-eye you need. Allow at least three hours post-meal before you turn in so your body has a chance to digest the food and you don't feel too uncomfortable to sleep.

Broccoli

Broccoli is a nutrition powerhouse, but its slow-to-digest fiber will keep your body working hard into the night. Broccoli and its relatives cauliflower and brussels sprouts also contain an indigestible sugar that will produce large amounts of gas.