More than 700 million people with untreated hypertension

The number of adults aged 30–79 years with hypertension has increased from 650 million to 1.28 billion in the last thirty years, according to the first comprehensive global analysis of trends in hypertension prevalence, detection, treatment and control, led by Imperial College London and WHO, and published in The Lancet. Nearly half these people did not know they had hypertension.

Hypertension significantly increases the risk of heart, brain and kidney diseases, and is one of the top causes of death and disease throughout the world. It can be easily detected through measuring blood pressure, at home or in a health centre, and can often be treated effectively with medications that are low cost.

The study, conducted by a global network of physicians and researchers, covered the period 1990–2019. It used blood pressure measurement and treatment data from over 100 million people aged 30–79 years in 184 countries, together covering 99% of the global population, which makes it the most comprehensive review of global trends in hypertension to date.

By analysing this massive amount of data, the researchers found that there was little change in the overall rate of hypertension in the world from 1990 to 2019, but the burden has shifted from wealthy nations to low- and middle-income countries. The rate of hypertension has decreased in wealthy countries – which now typically have some of the lowest rates – but has increased in many low- or middle-income countries.

As a result, Canada, Peru and Switzerland had among the lowest prevalence of hypertension in the world in 2019, while some of the highest rates were seen in the Dominican Republic, Jamaica and Paraguay for women and Hungary, Paraguay and Poland for men. (See notes to editors for country breakdowns/rankings).

According to the WHO, although the percent of people who have hypertension has changed little since 1990, the number of people with hypertension doubled to 1.28 billion. This was primarily due to population growth and ageing. In 2019, over one billion people with hypertension (82% of all people with hypertension in the world) lived in low- and middle-income countries.

Study links sleep apnea in children to increased risk of high blood pressure in teen years

Children with obstructive sleep apnea are nearly three times more likely to develop high blood pressure when they become teenagers than children who never experience sleep apnea, according to a new study funded by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. However, children whose sleep apnea improves as they grow into adolescence do not show an increased chance of having high blood pressure, which is a major risk factor for heart disease.

The long-term study, one of the largest of its kind in the pediatric population, underscores the seriousness of sleep apnea in children and the importance of early treatment, the researchers said. Their findings appear online in the journal JAMA Cardiology.

Obstructive sleep apnea, a common sleep disorder that affects millions worldwide, causes people to briefly and repeatedly stop breathing during sleep. While it occurs mostly in adults, an estimated 10% of school-aged children can also suffer from it. Although almost half of them outgrow the disorder by the time they reach adolescence, another half remain with a chronic and persistent problem. As physicians cannot accurately predict who will outgrow sleep apnea, early treatment may be beneficial to the long-term cardiovascular health of children, the researchers suggest.

While past studies have linked sleep apnea to high blood pressure and an increased risk of heart disease in adults, few have examined the long-term health impact of the disorder in children as they transition to adolescence, said lead study author Julio Fernandez-Mendoza, Ph.D., an associate professor at the Sleep Research and Treatment Center at Penn State College of Medicine in Hershey, Pennsylvania.

“Our study showed that pediatric sleep apnea can act as a gateway to future hypertension,” Fernandez-Mendoza said. “Because most cases of sleep apnea go undiagnosed in adults and children alike the problem needs more attention. Sleep apnea and its risk factors should be screened for, monitored, and targeted early in life to prevent future cardiovascular disease.”

Marishka Brown, Ph.D., director of the NHLBI’s National Center on Sleep Disorders Research, noted that most of the sleep apnea findings in pediatric patients focus on the disorder’s behavioral effects, such as sleepiness, hyperactivity, and cognition.

“There is limited data on either the short- or long-term impact on cardiovascular risk in this population,” she said. “The new findings address this knowledge gap and raise awareness of sleep-disordered breathing in children as a public health problem.”

In the study, the researchers enrolled 421 children ages 5 to 12 years and monitored them overnight in a sleep lab. They found that about 12% had obstructive sleep apnea according to pediatric diagnostic criteria. The researchers also measured blood pressure levels in this group.

After eight years, the researchers evaluated these children again for sleep apnea and high blood pressure. At this point, the participants were on average 16 years old (ages 12 to 23 years).

The researchers found that children whose sleep apnea continued into adolescence were nearly three times more likely to develop high blood pressure compared to those who never had sleep apnea. Those whose sleep apnea began as teenagers and met adult diagnostic criteria were nearly twice as likely to develop high blood pressure than those without sleep apnea. In addition, these teens were also more likely to have a specific form of high blood pressure called orthostatic hypertension, which occurs when standing up rapidly from a prone position and is considered a strong risk factor for heart disease in adulthood.

The exact biological mechanisms underlying the link between childhood sleep apnea and elevated blood pressure in adolescence are unclear. Obesity is a driving factor of sleep apnea even in the young, the researchers said.  Growing evidence also suggests that increased inflammation, oxidative stress, and impaired heart function caused by changes in the sympathetic nervous system may be at play, given the independent contribution of sleep apnea to high blood pressure and orthostatic hypertension observed, they added.

Like adult sleep apnea, pediatric sleep apnea can be treated. For some specific cases, surgical removal of the tonsils and adenoids can help. Other cases may require the use of a CPAP machine (continuous positive airway pressure), a device that delivers air through a mask to keep the airway open when worn during sleep. For children with obesity, adopting a healthy eating and exercise plan that leads to weight loss can also help. Fernandez-Mendoza encourages parents to talk to their child’s pediatrician if they suspect sleep apnea and encourages clinicians to integrate behavioral weight loss in their management of overweight youth with sleep apnea.

Fernandez-Mendoza is currently conducting another follow-up study of these youth, now aged 20 to 31 years old, to better understand the long-term impact of childhood sleep apnea on cardiovascular health in adulthood. 

Long working hours increasing deaths from heart disease and stroke: WHO, ILO

Long working hours led to 745 000 deaths from stroke and ischemic heart disease in 2016, a 29 per cent increase since 2000, according to the latest estimates by the World Health Organization and the International Labour Organization published in Environment International.  

In a first global analysis of the loss of life and health associated with working long hours, WHO and ILO estimate that, in 2016, 398 000 people died from stroke and 347 000 from heart disease as a result of having worked at least 55 hours a week. Between 2000 and 2016, the number of deaths from heart disease due to working long hours increased by 42%, and from stroke by 19%.

This work-related disease burden is particularly significant in men (72% of deaths occurred among males), people living in the Western Pacific and South-East Asia regions, and middle-aged or older workers. Most of the deaths recorded were among people dying aged 60-79 years, who had worked for 55 hours or more per week between the ages of 45 and 74 years.

With working long hours now known to be responsible for about one-third of the total estimated work-related burden of disease, it is established as the risk factor with the largest occupational disease burden. This shifts thinking towards a relatively new and more psychosocial occupational risk factor to human health.

The study concludes that working 55 or more hours per week is associated with an estimated 35% higher risk of a stroke and a 17% higher risk of dying from ischemic heart disease, compared to working 35-40 hours a week.

Further, the number of people working long hours is increasing, and currently stands at 9% of the total population globally.  This trend puts even more people at risk of work-related disability and early death.

The new analysis comes as the COVID-19 pandemic shines a spotlight on managing working hours; the pandemic is accelerating developments that could feed the trend towards increased working time.

“The COVID-19 pandemic has significantly changed the way many people work,“ said Dr Tedros Adhanom Ghebreyesus, WHO Director-General. “Teleworking has become the norm in many industries, often blurring the boundaries between home and work. In addition, many businesses have been forced to scale back or shut down operations to save money, and people who are still on the payroll end up working longer hours. No job is worth the risk of stroke or heart disease. Governments, employers and workers need to work together to agree on limits to protect the health of workers.”

Are eggs good or bad for your health?

Walter Willett, professor of epidemiology and nutrition at Harvard T.H. Chan School of Public Health, is one of the skeptics. Willett, who co-authored a study last year that found that eating one egg per day did not increase the risk of cardiovascular disease, commented on the new findings in a February 9, 2021, CNN article. “The study results are problematic because they only asked people once about their egg consumption, then followed them for many years without checking to see if their diet had changed,” he said. “They’re only getting a snapshot in time.”

While there has been ongoing concern that the cholesterol in eggs could lead to health problems, Willett said that cholesterol’s role in the diet is “more complicated than we used to think.” He said that the key is to look at the overall nutritional pros and cons of a particular food, as well as what that food is replacing in the diet.

“If someone replaces eggs with doughnuts, other refined starches and sugar or saturated fats, I’d rather they eat eggs,” Willett said. “But for someone who really wants to be in optimal health, putting the emphasis on plant-based protein sources like steel-cut oatmeal and nuts would be a better way to go.” He added that certain populations, such as people on cholesterol-lowering medications, “would be better off keeping eggs on the low side.”

In general, he said, “I think the old recommendation of not more than two eggs per week for most people is actually still a good recommendation.”

Close to half of U.S. population projected to have obesity by 2030

About half of the adult U.S. population will have obesity and about a quarter will have severe obesity by 2030, according to a new study led by Harvard T.H. Chan School of Public Health.

photo credit: Harvard T.H. Chan

The study also predicts that in 29 states, more than half of the population will have obesity, and all states will have a prevalence of obesity higher than 35%. The study’s researchers estimate that, currently, 40% of American adults have obesity and 18% have severe obesity.

The study was published in the December 19, 2019 issue of the New England Journal of Medicine.

The researchers said the predictions are troubling because the health and economic effects of obesity and severe obesity take a toll on several aspects of society. “Obesity, and especially severe obesity, are associated with increased rates of chronic disease and medical spending, and have negative consequences for life expectancy,” said Steven Gortmaker, professor of the practice of health sociology at Harvard Chan School and senior author of the study.

For the study, the researchers used self-reported body mass index (BMI) data from more than 6.2 million adults who participated in the Behavioral Risk Factor Surveillance System Survey (BRFSS) between 1993 and 2016. Body mass index (BMI) is calculated by dividing a person’s weight in kilograms by the square of their height in meters. Obesity is defined as a BMI of 30 or higher, and severe obesity is a BMI of 35 or higher.

Self-reported BMIs are frequently biased, so the researchers used novel statistical methods to correct for this bias.

The large amount of data collected in the BRFSS allowed the researchers to drill down for obesity rates for specific states, income levels, and subpopulations.

The results showed that by 2030, several states will have obesity prevalence close to 60%, while the lowest states will be approaching 40%. The researchers predicted that nationally, severe obesity will likely be the most common BMI category for women, non-Hispanic black adults, and those with annual incomes below $50,000 per year.

“The high projected prevalence of severe obesity among low-income adults has substantial implications for future Medicaid costs,” said lead author Zachary Ward, programmer/analyst at Harvard Chan School’s Center for Health Decision Science. “In addition, the effect of weight stigma could have far-reaching implications for socioeconomic disparities as severe obesity becomes the most common BMI category among low-income adults in nearly every state.”

Ward and his co-authors said that the study could help inform state policy makers. For example, previous research suggests that sugar-sweetened beverage taxes have been an effective and cost-effective intervention for curtailing the rise in obesity rates. “Prevention is going to be key to better managing this epidemic,” said Ward.

Three public health interventions could prevent 94 million premature deaths

A worldwide effort to lower people’s blood pressure, cut their sodium intake, and eliminate trans fat from their diet could dramatically reduce the incidence of premature death from cardiovascular disease (CVD) over a quarter century, according to a new study led by Harvard T.H. Chan School of Public Health.

“Focusing our resources on the combination of these three interventions can have a huge potential impact on cardiovascular health through 2040,” said lead author Goodarz Danaei, associate professor of global health at Harvard Chan School.

The study was published online June 10, 2019 in the journal Circulation.

Researchers used global data from multiple studies and estimates from the World Health Organization in making their calculations.

They estimated that scaling up treatment of high blood pressure to 70% of the world’s population could extend the lives of 39.4 million people. Cutting sodium intake by 30% could stave off another 40 million deaths and could also help decrease high blood pressure, a major risk factor for CVD. And eliminating trans fatcould prevent 14.8 million early deaths.

More than half of all delayed deaths, and two-thirds of deaths delayed before age 70, are projected to be among men, who have the highest numbers of noncommunicable disease deaths globally, researchers found. Regions expected to benefit most from the interventions include East Asia, the Pacific, and South Asia, as well as countries in sub-Saharan Africa.

The authors said that a variety of programs and policies would be necessary to reduce premature CVD-related deaths. One important strategy would be to increase the use of blood pressure medications, many of which are safe and affordable.

The researchers acknowledged that scaling up the three interventions would be a “huge challenge,” requiring countries to commit additional resources to boost health care capacity and quality. But they added that previous analyses have shown that the interventions are achievable and affordable. For example, a Kaiser Permanente program in Northern California increased control of hypertension to 90% among thousands of the health system’s patients between 2001 and 2013, using strategies such as improved treatment protocols, patient-friendly services, and healthcare information systems that facilitate tracking people with hypertension. Similar approaches have been adapted and tested in some low- and middle-income countries, leading to notable improvements in hypertension treatment and control, the authors said.

“These are realistic goals that have been shown to be attainable on smaller scales,” said Danaei. “We need the commitment to scale up the programs to achieve them globally.”

“Three Public Health Interventions Could Save 94 Million Lives in 25 Years,” Vasilis Kontis, Laura K. Cobb, Colin D. Mathers, Thomas R. Frieden, Majid Ezzati, Goodarz Danaei, Circulation, June 10, 2019, doi: 10.1161/CIRCULATIONAHA.118.038160

Increasing red meat consumption linked with higher risk of premature death

People who increased their daily servings of red meat over an eight-year period were more likely to die during the subsequent eight years compared to people who did not increase their red meat consumption, according to a new study led by researchers from Harvard T.H. Chan School of Public Health.

The study also found that decreasing red meat and simultaneously increasing healthy alternative food choices over time was associated with lower mortality.

The study was published online June 12, 2019 in BMJ.

A large body of evidence has shown that higher consumption of red meat, especially processed red meat, is associated with higher risk of type 2 diabetes, cardiovascular disease, certain types of cancers including those of the colon and rectum, and premature death. This is the first longitudinal study to examine how changes in red meat consumption over time may influence risk of early death.

For this study, researchers used health data from 53,553 women in The Nurses’ Health Study and 27,916 men in the Health Professionals Follow-up Study who were free of cardiovascular disease and cancer at baseline. They looked at whether changes in red meat consumption from 1986–1994 predicted mortality in 1994–2002, and whether changes from 1994–2002 predicted mortality in 2002–2010.

Increasing total processed meat intake by half a daily serving or more was associated with a 13% higher risk of mortality from all causes. The same amount of unprocessed meat increased mortality risk by 9%. The researchers also found significant associations between increased red meat consumption and increased deaths due to cardiovascular disease, respiratory disease, and neurodegenerative disease.

The association of increases in red meat consumption with increased relative risk of premature mortality was consistent across participants irrespective of age, physical activity level, dietary quality, smoking status, or alcohol consumption, according to the researchers.

Study results also showed that, overall, a decrease in red meat together with an increase in nuts, fish, poultry without skin, dairy, eggs, whole grains, or vegetables over eight years was associated with a lower risk of death in the subsequent eight years.

The researchers suggest that the association between red meat consumption and increased risk of death may be due to a combination of components that promote cardiometabolic disturbances, including saturated fat, cholesterol, heme iron, preservatives, and carcinogenic compounds produced by high temperature cooking. Red meat consumption has also recently been linked to gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) that might promote atherosclerosis.

“This long-term study provides further evidence that reducing red meat intake while eating other protein foods or more whole grains and vegetables may reduce risk of premature death. To improve both human health and environmental sustainability, it is important to adopt a Mediterranean-style or other diet that emphasizes healthy plant foods,” said senior author Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology and chair, Department of Nutrition.

The first author of the study is Yan Zheng, a former postdoctoral associate in the Department of Nutrition at Harvard Chan School and now a professor at Fudan University, Shanghai, China. Other Harvard Chan School authors include Yanping Li, Ambika Satija, Mercedes Sotos-Prieto, Eric Rimm, and Walter Willett.

The study cohorts were supported by grants of UM1 CA186107 and UM1 CA167552 from the National Institutes of Health. The current study was supported by grants from the National Heart, Lung, and Blood Institute (HL071981, HL034594, HL60712, HL126024), the National Institute of Diabetes and Digestive and Kidney Diseases (DK091718, DK100383, DK112940, DK078616), and the Boston Obesity Nutrition Research Center (DK46200).

“Association of Changes in Red Meat Consumption with Total and Cause-Specific Mortality Among U.S. Women and Men: Two Prospective Cohort Studies,” Yan Zheng, Yanping Li, Ambika Satija, An Pan, Mercedes Sotos-Prieto, Eric Rimm, Walter C. Willett, Frank B. Hu, BMJ, online June 12, 2019, doi: 10.1136/bmj.l2110.