Going to bed early and waking up early may help to provide some protection against depression, a new study suggests.If you are a morning person, you may be at reduced risk for major depression, a new study suggests.Several studies of the body’s circadian sleep-wake cycle have shown that being an early bird is associated with a lower risk for depression. But those studies were observational so could not prove cause and effect.For example, people who are early birds may have other health or lifestyle behaviors that reduce their risk for depression — they may have a healthier diet, for example, exercise more, or have fewer health conditions, such as chronic pain, that are associated with depression. All these factors, and many others, could explain the decreased risk for depression, and not the fact of being an early bird. Moreover, depression itself causes sleep disturbances, so it could be that depression is a cause of being a night owl, rather than the other way around.The new study, however, offers more compelling evidence that going to bed early and waking early may, in itself, provide protection against depression, independent of other factors. The study, published in JAMA Psychiatry, uses a research method called Mendelian randomization that helps pinpoint the cause of what may be a cause-and-effect relationship.With Mendelian randomization, researchers can compare large groups of people based on genetic variants that are independent of other health or behavioral characteristics — in this case, the tendency to being a night owl or a morning person, inherited traits that are randomly allocated during our development in the womb. More than 340 genetic variants associated with circadian sleep rhythm have been identified, and the researchers can compare large groups of people with the genetic variants for being a morning person with groups that lack them. Nature has, in essence, set up the randomized experiment for them.For the study, the scientists used two genetic databases of more than 800,000 adults to do a Mendelian randomization study of circadian rhythm and the risk for depression. They not only had genetic data, but also data on diagnoses of major depression and information on when people went to bed and woke up, collected with both self-reports and sleep laboratory records, which the researchers used to track the midpoint of sleep, a helpful scientific measure of someone’s sleep tendencies. A morning person who tended to go to bed at 10 and wake up at 6, for example, would have a sleep midpoint of 2 a.m.They found that in people with the genetic variants for being an early bird, for every hour earlier the sleep midpoint, there was a 23 percent lower risk of major depression.Dr. Till Roenneberg, an expert in chronobiology who was not involved in the research, said a shortcoming of the study was that the scientists had no data on when these people had to rise for work or other obligations. Even with Mendelian randomization, he said, they can’t account for the fact that late types often need to go to work too early, which in itself may contribute to depression.“They’ve drawn the right conclusions from their data,” he said, “but life is more complicated than that.”If you are a night owl, will changing your habits alleviate depression or decrease the risk for developing it? Not necessarily, said the lead author, Dr. Iyas Daghlas, a resident physician at the University of California, San Francisco. The study, he said, looks at large groups of people, not individuals.“This data tells us that certain trends in society” — such as using smartphones and other blue light devices at night, which make us go to sleep later — “may be having an effect on the level of depression in the population,” he said. “These results do not say that if you go to sleep earlier, you’ll get rid of depression. Discovering which intervention in which populations will be effective — that has to be left to clinical trials.”Still, he said, “While our data doesn’t tell us where the sweet spot is, I would say that if you’re an evening person, especially one who has to wake up early, advancing your bedtime about an hour or so is a safe intervention that might be helpful for your mental health.”

Women, but not men, with even mildly elevated blood pressure in their early 40s were at increased risk for later heart disease and early death.High blood pressure in younger people may be particularly hazardous for women, a new study suggests. The study found that women — but not men — with even mildly elevated blood pressure in their early 40s may be at substantially increased risk for later coronary disease and death.In 1992, Norwegian researchers began studying 12,329 men and women whose average age was 41. They tracked their blood pressure and cardiovascular health for an average of 16 years.At the start, high blood pressure was much less common in women than in men: 25 percent of women and 35 percent of men had stage 1 hypertension, which the American Heart Association defines as a reading of 130/80 to 139/89. (A reading under 120/80 is considered normal.) Fourteen percent of women and 31 percent of men had stage 2 hypertension, defined as 140/90 or higher. The women also had fewer risk factors for heart disease: They tended to have lower B.M.I.s and lower cholesterol levels, and fewer of them were smokers.During the follow-up period, 1.4 percent of the women and 5.7 percent of the men had been hospitalized with or died from cardiovascular disease.Compared with women who had normal blood pressure at the start of the study, those with stage 1 hypertension had more than double the risk of heart disease. In men, this association was statistically insignificant. The study, in the European Journal of Preventive Cardiology, controlled for diabetes, B.M.I., cholesterol, smoking and physical activity.The authors acknowledge that the study had limitations. It was done in a small geographic area in Norway, and the subjects were primarily Caucasian. Moreover, the researchers had no information about hypertension treatment or the use of cholesterol-lowering drugs during the follow-up period.Still, “the emerging evidence is that hypertension is worse for female hearts than for male hearts,” said the lead author, Dr. Ester Kringeland, an internal medicine specialist at the University of Bergen in Norway, “and the risk starts at a lower blood pressure level in women.”Dr. Joyce M. Oen-Hsiao, an assistant professor of medicine at Yale who was not involved in the work, said, “It’s a well-designed study. Most of us just look at risk factors, and we never really break it down by gender. That’s the novelty of this paper — that there’s a statistical difference between men and women. And if we can replicate this finding in our more diverse population, it will change primary prevention.”Current American Heart Association guidelines say that in otherwise healthy people, high blood pressure up to 130/80 can usually be managed with lifestyle changes. For readings from 130/80 to 139/89, the group recommends antihypertensive drugs, but only for people with other cardiovascular disease risk factors. At 140/90 or higher, medication is indicated in almost all cases. But the guidelines make no distinction between men and women.Dr. Kringeland said that one reading, or a reading with a home blood pressure monitor, is not enough to make a diagnosis. “A doctor has to take three readings, then average the last two. And to diagnose hypertension, you need at least two visits to the doctor.”The question of whether a healthy woman in her 40s with a reading of 130/80 should be treated with antihypertensive drugs is still not settled.“In some women — those with diabetes, for example — treatment is indicated even at this level,” Dr. Kringeland said. “But in women who are otherwise healthy? We don’t have the answer yet. Blood pressure medicines have side effects, and you have to look at the risk-benefit ratio. We need more research about cardiac disease in women.”

People with sleep apnea who can’t tolerate the noise and discomfort of a CPAP machine might benefit from a mouth guard or surgery.Many people wear a CPAP machine at night to treat the interrupted breathing of obstructive sleep apnea, a condition that affects an estimated 22 million Americans. But CPAP machines can be noisy, cumbersome and uncomfortable, and many people stop using the devices altogether, which can have dire long-term consequences.Mouth guards may be a more comfortable and easy-to-use alternative for many people with obstructive sleep apnea, according to a new report. The study, published in Laryngoscope, looked at 347 people with sleep apnea who were fitted with a mouth guard by an otolaryngologist. Two-thirds of patients reported they were comfortable wearing the devices, and the devices appeared to be effective in helping to relieve the disordered breathing of obstructive sleep apnea.The lead author of the study, Dr. Guillaume Buiret, head of otolaryngology at Valence Hospital in Valence, France, said that if he had sleep apnea, he would choose an oral appliance first.“It’s easy to tolerate, effective and it costs a lot less than CPAP,” he said. “Thirty to 40 percent of our patients can’t use CPAP, and these patients almost always find the dental appliance helpful. I would recommend it as a first-line treatment”Loud snoring may be the most obvious consequence of sleep apnea, but the condition, if left untreated, can lead to a broad range of complications, including high blood pressure, heart disease, liver dysfunction and Type 2 diabetes.The problem develops when the soft tissue at the back of the throat collapses during sleep, blocking the airway. This leads to breathing cessation for brief periods, gasping for air, difficulty staying asleep, and all the problems of daytime sleepiness, from poor job performance to fatal accidents. Animals can have it too — bulldogs, for example, have a narrow airway and a soft palate that can easily block it. Their sleep apnea is almost identical to the human version.The severity of the condition varies widely from a very mild problem that may need no treatment at all to severe or even life-threatening disease. Dr. Sara E. Benjamin, a neurologist and sleep specialist at Johns Hopkins, said that spending a night in a sleep laboratory monitored by a technician is the best way to diagnose apnea. A lab study offers the most thorough analysis, and can detect many other sleep problems besides apnea, but there are home test kits that are easy to use and cost-effective. They test breathing effort and oxygen levels, but not the brain waves, muscle tone and leg movements that a lab test records.How can you know that you need a sleep assessment? “It’s a low standard to get evaluated, either by home testing or in a sleep lab,” Dr. Benjamin said. “If a person feels sleep problems are impacting daily activities, that’s enough to go and get evaluated. If the cause is a breathing problem, you don’t want to ignore it.”A CPAP — continuous positive airway pressure — machine is usually the first option for treating sleep apnea. The device has a motor that delivers pressurized air through a tube attached to a mask that covers the nose, or both the nose and the mouth. This keeps the airway open. Some machines can automatically change the pressure to compensate for changes in sleep position; others require manual adjustment. Headgear varies, but all have adjustable straps to get the right fit. There are newer models that can deliver heated or humidified air, depending on the patient’s preferences, and there are small travel models as well.But many patients find sleeping with a mouth guard less awkward or unpleasant than using a CPAP machine. The technical term for these appliances is mandibular advancement devices, so named because they work by pushing the lower jaw forward, which in most people helps keep the airway open. There are many variations of these gadgets available in drugstores, but a dentist can design a more effective personalized appliance, and modify or adjust it when necessary. The patients in the Laryngoscope study were all re-examined after the first fitting, and most needed adjustments over a two- to four-week period.“We recommend a custom device made by a dentist,” Dr. Benjamin said. “And you should be retested to see how well it’s working. There’s subjective and objective improvement that should be tracked.”But there are people for whom neither CPAP nor dental appliances work, either because they cannot use them consistently or correctly, or because the devices themselves do not solve the problem even when used properly. For these patients, there are various effective surgical procedures.The most common is soft tissue surgery, which involves modifying or excising tissue at the back of the mouth. Depending on the structures and musculature of the mouth, the surgeon can trim the soft palate and the uvula, remove the tonsils, shrink tissues with a heated instrument, straighten a deviated septum, or alter the position of the tongue muscles, all with the aim of improving air flow.There are also bone surgeries that move the jaw forward to make the entire breathing space larger, a procedure that can involve a protracted recovery period.In 2014, the Food and Drug Administration approved a device called Inspire Upper Airway Stimulation. This is a small appliance implanted under the skin like a heart pacemaker. Using two electrical leads, it senses the breathing pattern and stimulates the nerve that controls the tongue to move it out of the way and allow air to pass freely. Implanting it is a day surgery procedure that takes about two hours.“It doesn’t change the anatomy, and recovery is easier than with other surgeries,” said Dr. Maria V. Suurna, an associate professor of otolaryngology at Weill Cornell Medicine who specializes in surgery for sleep apnea. “It’s effective. It has the lowest complication rate of all the surgeries.“But it’s not for everyone. It’s approved only for adults 18 and older who are not overweight and who have moderate to severe apnea.” Some people may be ineligible because of the structure of their anatomy.“Surgery is tricky,” Dr. Suurna said. “But there’s no ideal treatment for apnea. Each has pros and cons, benefits and risks.”

Even short-term exposure to polluted air may impair mental ability in the elderly. Aspirin and other NSAIDs showed some protective effects.Long-term exposure to air pollution has many health consequences, including accelerating brain aging and increasing the risk for dementia. Now new research suggests that short-term exposure to polluted air, even at levels generally considered “acceptable,” may impair mental ability in the elderly.Scientists studied 954 men, average age 69, living in the greater Boston area. The men were tested at the start of the study and several times over the next 28 days using the Mini-Mental State Examination, or MMSE, a widely used test of cognitive ability. The test includes simple questions like “What year is this?” and “What season is it?,” and requires tasks like counting backward by sevens from 100. Correctly answering fewer than 25 of its 30 questions suggests mild dementia.Over the month, the researchers measured air levels of what’s known as PM 2.5, particles of soot and other fine particulate matter with a diameter of up to 2.5 microns, small enough to enter the lungs and move into bloodstream. There is no safe level of PM 2.5, but the Environmental Protection Agency considers air acceptable when it is under 12 micrograms per cubic meter. During the testing period, PM 2.5 levels in Boston averaged 10.77.Higher PM 2.5 was consistently associated with lower test scores. In weeks with the highest levels of air pollution, the men were 63 percent more likely to score below 25 on the MMSE than in weeks with the lowest levels. The study, in Nature Aging, adjusted for age, B.M.I., coronary heart disease, diabetes, alcohol consumption, smoking, high blood pressure and other factors.Dr. Andrea A. Baccarelli, the senior author and a professor of environmental science at the Columbia Mailman School of Public Health, said that these short-term effects may be reversible. “When air pollution goes down,” he said, “the brain reboots and goes back to normal. However, if repeated, these episodes produce long-term damage to the brain.”“Some of these particles come from natural sources — sea salt, for example, soil and pollen,” Dr. Baccarelli added. “We’ll never be completely free of them. But the ones generated by humans are much worse. The good news is that we’re at a point where we have the technology to reduce air pollution even further.”In a finding the researchers described as “intriguing,” they discovered that men taking NSAIDs — aspirin and other nonsteroidal anti-inflammatory drugs — were partially protected from the negative cognitive effects of pollution. They speculate that NSAIDs may reduce the inflammatory response to pollutants in the brain and nervous system.“This is an impressive study,” said Robert M. Bilder, a professor of psychiatry and psychology at the University of California, Los Angeles, who was not involved in the work. But, he said, the study is observational and not a randomized trial, so does not prove cause and effect. Moreover, it was done only in older white men, many of whom were overweight or had a history of smoking. “Given the established risks of PM and other environmental hazards on cognition, and particularly given their disproportionate impacts on racial and ethnic minority communities,” he said, “we urgently need research that goes beyond the study of white men.”Dr. Bilder pointed out that “the study reveals a potentially important interaction between the use of NSAIDs and exposures to environmental risk. We need controlled clinical trials and further basic research to specify the mechanisms through which the NSAIDs may work.”Dr. Baccarelli agreed. “I would love to do a randomized trial to see if there is a real benefit,” he said. For now, “anything that promotes a healthy lifestyle helps protect against air pollution. A healthy diet helps. Physical exercise helps. But I wouldn’t tell anyone to take aspirin for protection against air pollution.”Nathalie LeesJoin us for Well’s Fresh Start Challenge! Starting Monday May 17 we’ll text you daily tips for mindful living. To sign up, just text “Hi” (or any word) to 917-809-4995 for a link to join. (Message and data rates may apply.)

People taking cholesterol-lowering statin drugs often report muscle pain, but the pain may be the same when they take a look-alike placebo pill.Many people who take the cholesterol-lowering statin drugs report that they cause muscle pain, but a randomized trial suggests that the pain is no different when they take a placebo pill.In rare cases, statins are known to cause a severe muscle condition called rhabdomyolysis, in which skeletal muscle tissue is destroyed, leading to serious complications. But much more frequently, people complain that the drugs simply cause muscle pain.Whether statins are responsible for the muscle pain, however, remains uncertain. Muscle pain has many causes and is common in the older age group using statins, so determining whether statins are causing the pain is not easy. Results from observational studies, along with many media reports, may have led some to unnecessarily discontinue a treatment that is potentially lifesaving.This new study, published in BMJ, involved a series of what is known as n-of-1 clinical trials, a methodology that allows researchers to examine the results of treatment and placebo in individual patients, rather than studying them as a group. In effect, each patient serves as his or her own control.Mike Mergen for The New York TimesResearchers assembled 200 people in England and Wales who had either stopped or planned to stop taking statins because of intolerable muscle pain. For a year, each patient randomly took either a statin or a placebo pill over six two-month periods. Half the time they received 20 milligrams of Lipitor, and the other half they got a look-alike dummy pill. Until the end of the study, neither the researchers nor the patients knew when they were taking the statin and when they were taking the placebo.During the last seven days of each two-month phase, the researchers measured each patient’s pain daily using a validated 10-point visual pain scale, with 10 indicating the worst possible pain. They also tracked other aspects of daily life, including the patient’s general activity level, mood, comfort in walking, ability to pursue normal work activities, social relationships, sleep and enjoyment of life.The study found no differences between the statin and placebo periods in either muscle pain or reports on daily life activities and moods. Nine percent withdrew because of pain while they were on statins, but so did 7 percent who were taking placebos, an insignificant difference.“These studies are difficult to do,” said Dr. Henry N. Ginsberg, a professor of medicine at Columbia who was not involved in the work. “This one is done as well as you can, and it’s a nice one to talk about with patients. You can tell your patients, ‘They’ve done studies in people like you, and these people couldn’t tell the difference between placebo and medicine.’”Three months after the final treatment, when the patients had been informed of their results, the researchers asked them whether they had restarted statins, or intended to, and whether they found their own trial result helpful in making their decision. Most of the patients said that the trial was helpful, and more than two-thirds reported that they planned to start taking statins again.The lead author, Dr. Liam Smeeth, a primary care physician and professor of clinical epidemiology at the London School of Hygiene and Tropical Medicine, said that when people stop statins because of muscle pain “they’re missing out on the huge benefits — reducing the risk of heart attack or stroke by about a third. What we’ve shown is that among these people who gave up their medicine because of pain — and their pain was real — it wasn’t made worse by statins.”

The younger the age at diagnosis for Type 2 diabetes, the higher the risk for Alzheimer’s disease and other forms of dementia years later.Type 2 diabetes is a chronic, progressive illness that can have devastating complications, including hearing loss, blindness, heart disease, stroke, kidney failure and vascular damage so severe as to require limb amputation. Now a new study underscores the toll that diabetes may take on the brain. It found that Type 2 diabetes is linked to an increased risk for Alzheimer’s disease and other forms of dementia later in life, and the younger the age at which diabetes is diagnosed, the greater the risk.The findings are especially concerning given the prevalence of diabetes among American adults and rising rates of diabetes in younger people. Once referred to as “adult-onset diabetes” to distinguish it from the immune-related “juvenile-onset” Type 1 disease that begins in childhood, Type 2 diabetes is seen in younger and younger people, largely tied to rising rates of obesity. The Centers for Disease Control and Prevention estimates that more than 34 million American adults have Type 2 diabetes, including more than a quarter of those 65 and over. About 17.5 percent of those aged 45 to 64 have Type 2 disease, as do 4 percent of 18- to 44-year-olds.“This is an important study from a public health perspective,” said the director of the Yale Diabetes Center, Dr. Silvio Inzucchi, who was not involved in the research. “The complications of diabetes are numerous, but the brain effects are not well studied. Type 2 diabetes is now being diagnosed in children, and at the same time there’s an aging population.”For the new study, published in JAMA, British researchers tracked diabetes diagnoses among 10,095 men and women who were 35 to 55 at the start of the project, in 1985 to 1988, and free of the disease at the time.They followed them with clinical examinations every four or five years through 2019. At each examination, the researchers took blood samples to evaluate fasting glucose levels, a measure used to detect diabetes, and recorded self-reported and doctor-diagnosed cases of Type 2 disease.The researchers also determined dementia cases using British government databases. Over an average follow-up of 32 years, they recorded 1,710 cases of Type 2 diabetes and 639 of dementia.The researchers calculated that each five-year earlier onset of diabetes was associated with a 24 percent increased risk of dementia. Compared with a person without diabetes, a 70-year-old diagnosed with Type 2 diabetes less than five years earlier had an 11 percent increased risk for dementia. But a diagnosis at age 65 was associated with a 53 percent increased risk of later dementia, and a diagnosis at 60 with a 77 percent increased risk. A person diagnosed with Type 2 at ages 55 to 59 had more than twice the risk of dementia in old age compared with a person in the same age group without diabetes.The study was observational, so could not prove that diabetes causes dementia. But it was long-running, with a large study population. The researchers controlled for many factors that affect the risk for dementia, including race, education, heart conditions, stroke, smoking and physical activity, and the diabetes-dementia link persisted.“These are exceptional data,” said Daniel Belsky, an assistant professor of epidemiology at Columbia Mailman School of Public Health who was not involved in the research. “These associations between the timing of onset of diabetes and development of dementia show the importance of a life-course approach to preventing degenerative disease.“We are an aging population, and the things we fear most are degenerative diseases like dementia, for which we have no cures, no therapies, and very few modifiable pathways to target for prevention,” Dr. Belsky said. “We can’t wait until people are in their 70s.”Why diabetes would be linked to dementia is unknown. “We can speculate on the mechanisms,” said the study’s senior author, Archana Singh-Manoux, a research professor at INSERM, the French national health institute. “Living a long time with diabetes and having hypoglycemic events is harmful, and there are neurotoxic effects of diabetes as well. The brain uses enormous amounts of glucose, so with insulin resistance, the way the brain uses glucose might be altered” in people with Type 2 diabetes.Type 2 can be managed and its complications reduced by monitoring blood sugar and conscientiously following a well-designed, personalized program of medication, exercise and diet. Is it possible that such a routine could minimize the risk for dementia later in life?“With better control, there was less cognitive decline than in those with poor control,” Dr. Singh-Manoux said. “So stick to your medication. Look after your glycemic markers. That’s the message for people who have diabetes.”