Roundup: Dementia in U.S. Estimated at 10% of Adults 65 and Older; Even Mild COVID Could Raise Risk of Blood Clots; and Update on Benefits of 10,000 Daily Steps

New Study Estimates Prevalence of Dementia in U.S. at 10% of Adults Aged 65 & Older

A newly released study based on research obtained in 2016 and 2017 finds that 10 percent of U.S. adults ages 65 and older may have dementia, while another 22 percent may have mild cognitive impairment.

The study from Columbia University researchers is believed to be the first nationally representative report on the prevalence of dementia and cognitive impairment in more than 20 years. It is published in the journal JAMA Neurology.

The findings are based on data received from 3,500 individuals enrolled in the nationally representative Health and Retirement Study. Between 2016 and 2017, each participant completed a “comprehensive set of neuropsychological tests and in-depth interviews, which were used to develop an algorithm for diagnosing dementia or mild cognitive impairment,” said a news release from Columbia University researchers.  

Rates of dementia and mild cognitive impairment increased significantly with age among the participants: 3 percent of those between 65 and 69 had dementia, rising to 35 percent for people aged 90 and older. 

Dementia is a general term that refers to loss of memory, language, problem-solving or other thinking abilities that are severe enough to interfere with daily living. Mild cognitive impairment (MCI) is an early stage of memory loss or other loss of cognitive ability in individuals who are able to maintain independence and perform most activities of daily living.

“With increasing longevity and the aging of the Baby Boom generation, cognitive impairment is projected to increase significantly over the next few decades, affecting individuals, families, and programs that provide care and services for people with dementia,” said Jennifer J. Manly, PhD, the study’s lead author and professor of neuropsychology in neurology at Columbia University, in a statement.

Researchers also found a “disproportionate burden” of dementia among older adults who self-identified as Black or African American, and a higher burden of mild cognitive impairment among older adults who identify as Hispanic.

The researchers state that unlike previous major studies of dementia in the U.S., “participants in the new study are representative of older adults, enabling researchers to examine differences in the national prevalence of dementia and mild cognitive impairment by age, race and ethnicity, gender, and education.”

A report earlier this year from the Alzheimer’s Association estimates that 12 percent to 18 percent of people aged 60 or older have “mild cognitive impairment,” or MCI. That percentage is expected to continue to rise as the size of the U.S. population 65 and older continues to grow (from 58 million in 2021 to 88 million by 2050), the association states.

Even Those Who had Mild COVID During Pandemic’s First Year at Higher Risk of Blood Clots, New Study Finds

New research has found that people infected with just mild cases of COVID-19 during the first year of the pandemic had a higher risk of developing blood clots, compared to those who were not infected.

Scientists affiliated with Queen Mary University of London concluded that patients with mild Covid, or not requiring hospitalization, were 2.7 times more likely to develop blood clots than those who were not infected. Those patients were also 10 times more likely to die than people who did not get COVID. The study was published in the British Medical Journal’s Heart.

Nonetheless, those patients where were hospitalized with severe COVID carried the highest risks. They were 28 times more likely to develop blood clots, 22 times more likely to suffer heart failure and17 times more likely to suffer a stroke, the study found. Overall, they were over 100 times more likely to die than people who were not infected with COVID.

Overall, the researchers monitored 18,000 people who were infected with COVID during the first year of the pandemic and compared their health outcomes with nearly 34,000 people who didn’t contract COVID.  Their health statuses were tracked until the study ended in March 2021, or until they developed heart disease or died. Most of the research took place before COVID vaccines began to become available in the U.K. in December 2020.

“It is important to understand whether the augmented cardiovascular risk associated with COVID-19 is limited to those with severe disease or extends to the wider population of individuals with mild manifestations,” the study states. “This information would define the magnitude of any potential public health impact and guide appropriate targeting of healthcare strategies.” 

Taking 10,000 or Fewer Steps a Day: New Studies Reinforce Daily Walking’s Health Benefits

Two new studies – each involving 78,500 participants at middle age or older — add to the good news when it comes to taking up to 10,000 steps a day for a healthier and longer life. In the first study, published in the journal JAMA Internal Medicine, risk for premature death from cancer, cardiovascular disease and other causes, fell by up to 11 percent for every 2,000 steps taken each day.  

A second related study, published in JAMA Neurology,  found that walking more, up to 10,000 steps a day, was associated with a  decreased risk of heart disease, stroke and heart failure, several types of cancer and dementia.

“If combined with effective behavioral strategies, this information could be used to motivate the least active individuals to increase their steps and the more active individuals to reach the 10 000-step target,” concludes the study in JAMA Internal Medicine.

In both studies, participants measure their number of steps via tracking devices worn on their wrists. Researchers monitored their activity and health-related outcomes for a median of seven years.  Several previous studies have determined that 10,000 steps a day is the gold standard for reducing a person’s risk of chronic diseases, including cancers.

But individuals don’t have to reach 10,000 steps necessarily to achieve healthier living. The second study found that dementia risk was reduced with much fewer daily steps. “We estimated the minimum dose at approximately 3,800 steps per day, which was associated with 25 percent lower incident dementia,” researchers said.

A separate study released earlier this year found that walking 10,000 steps a day provides benefits to those with prediabetes and diabetes. Such a daily routine was best for reducing the risk of death from any cause for people who find it challenging to control blood sugar levels, according to researchers from the University of Seville, Spain who evaluated a group of U.S. adults with prediabetes and diabetes using data from the National Health and Nutrition Examination Survey at the U.S. Centers for Disease Control and Prevention (CDC).