Abnormal blood pressure in middle and late life influences dementia risk
August 14, 2019
Science Daily/Johns Hopkins Medicine
In a study that spanned two and a half decades and looked at data from more than 4,700 participants, Johns Hopkins researchers have added to evidence that abnormal blood pressure in midlife persisting into late life increases the likelihood of developing dementia. Although not designed to show cause and effect, the study suggests that maintaining a healthy blood pressure throughout life may be one way to help decrease one's risk of losing brain function.
"Our results suggest that one's blood pressure during midlife may influence how blood pressure later in life relates to dementia risk," says Keenan Walker, Ph.D., assistant professor of neurology at the Johns Hopkins University School of Medicine. "We found that individuals with high blood pressure in midlife may benefit from targeting their blood pressure to normal levels in later life, as having blood pressure that is too high or too low in late life may further increase dementia risk."
In their study, they found that those people with the high blood pressure condition hypertension during middle age and during late life were 49% more likely to develop dementia than those with normal blood pressure at both times. But, putting one at even greater risk was having hypertension in middle age and then having low blood pressure in late life, which increased one's dementia risk by 62%. The findings were published Aug. 13 in JAMA.
High blood pressure was considered any measurement more than 140/90 millimeters of mercury, whereas low blood pressure was defined as less than 90/60 millimeters of mercury. A cognitive exam, caregiver reports, hospitalization discharge codes and death certificates were used to classify participant brain function and determine cognitive impairment.
High blood pressure can be genetic, but can also be the result of not enough exercise and poor diet. As people age, the top blood pressure number (systolic) oftentimes increases while the bottom number (diastolic) can decrease due to structural changes in the blood vessels. Walker says dementia itself may lead to a lowering of blood pressure, as it may disrupt the brain's autonomic nervous system. Stiffening of the arteries from disease and physical frailty can also lead to low blood pressure in late life.
According to the Centers for Disease Control and Prevention, 75 million people in the U.S. have high blood pressure, and high blood pressure can raise the risk for heart disease, as well as other health conditions.
https://www.sciencedaily.com/releases/2019/08/190814081221.htm
Majority of older adults with probable dementia are likely unaware they have it
Less education and unaccompanied medical visits linked to lack of formal diagnosis or awareness of diagnosis
July 17, 2018
Science Daily/Johns Hopkins Medicine
An analysis of information gathered for an ongoing and federally sponsored study of aging and disability adds to evidence that a substantial majority of older adults with probable dementia in the United States have never been professionally diagnosed or are unaware they have been.
A Johns Hopkins Medicine analysis of information gathered for an ongoing and federally sponsored study of aging and disability adds to evidence that a substantial majority of older adults with probable dementia in the United States have never been professionally diagnosed or are unaware they have been.
A report of the findings was published in the July issue of the Journal of General Internal Medicine. Most of the findings, the researchers say, confirm previous similar estimates, but unaccompanied visits to a doctor or clinic emerged as a newly strong risk factor for lack of formal diagnosis or awareness of diagnosis.
"There is a huge population out there living with dementia who don't know about it," says Halima Amjad, M.D., M.P.H., assistant professor of medicine at the Johns Hopkins University School of Medicine and the study's lead author. "The implications are potentially profound for health care planning and delivery, patient-physician communication and much more," she says.
Overall, Amjad says, "If dementia is less severe and people are better able to perform day-to-day tasks independently, symptoms of cognitive loss are more likely masked, especially for patients who visit the doctor without a family member or friend who may be more aware of the patient's symptoms."
An estimated 5.7 million people in the United States live with dementia, according to the Alzheimer's Association, but only half of those have a documented, official diagnosis by a physician. Timely diagnosis is important for maintaining or improving health and planning care, says Amjad, so it's important to identify which populations are less likely to be diagnosed or less likely to be aware of their diagnosis.
Building on previous research, which identified activities and living conditions linked to dementia diagnosis, Amjad sought this time to pinpoint at-risk populations nationwide.
To do so, Amjad and the research team drew on data from the National Health and Aging Trends Study, an ongoing study of Medicare recipients ages 65 and older across the United States, and selected those who met criteria for probable dementia in 2011 and had three years of continuous fee-for-service Medicare claims before 2011. The latter information helped the researchers determine whether participants' physicians had billed for dementia diagnosis and/or care.
The research team identified 585 such adults and examined demographic data such as highest level of education attained, race/ethnicity and income, as well as data on whether participants were able to perform activities such as laundry, shopping or cooking on their own.
Among those with probable dementia, 58.7 percent were determined to be either undiagnosed (39.5 percent) or unaware of their diagnosis (19.2 percent).
Participants who were Hispanic, had less than a high school education, attended medical visits alone or were deemed more able to perform daily tasks were more likely to be undiagnosed. Specifically, those with at least a high school education had a 46 percent lower chance of being undiagnosed compared with those who had less education; and those who attended medical visits alone were twice as likely to be undiagnosed than those who were accompanied.
Participants who were diagnosed but unaware of their diagnosis had less education, attended visits alone more often and had fewer functional impairments. Those with at least a high school education had a 58 percent lower chance of being unaware compared with those who had less education. Those who attended medical visits alone were about twice as likely to be unaware than those who were accompanied. Each activity impairment decreased the chance of being unaware of diagnosis by 28 percent.
While Amjad acknowledges that the study is limited by potentially inaccurate self-reporting of dementia diagnoses, possible discrepancies between medical record documentation and billing codes, and the use of older data, she says the findings will likely help physicians be more alert to people who may need more careful screening.
"There are subsets of people doctors can focus on when implementing cognitive screening, such as minorities, those with lower levels of education and those who come in by themselves," says Amjad.
Looking forward, Amjad plans to study whether documentation of a dementia diagnosis is meaningful if patients and family members don't understand what a diagnosis means.
https://www.sciencedaily.com/releases/2018/07/180717094726.htm