Higher dementia risk in women with prolonged fertility
September 17, 2020
Science Daily/University of Gothenburg
Women with a longer reproductive period had an elevated risk for dementia in old age, compared with those who were fertile for a shorter period, a population-based study from the University of Gothenburg shows.
"Our results may explain why women have a higher risk of developing dementia and Alzheimer's disease than men after age 85, and provide further support for the hypothesis that estrogen affect the risk of dementia among women," says Jenna Najar, a medical doctor and doctoral student at Sahlgrenska Academy who also works at AgeCap, the Centre for Ageing and Health at the University of Gothenburg.
The study, now published in the journal Alzheimer's & Dementia, covers 1,364 women who were followed between 1968 and 2012 in the population studies collectively known as the "Prospective Population-based Study of Women in Gothenburg" (PPSW) and the "Gothenburg H70 Birth Cohort Studies in Sweden" (the H70 studies). The "reproduction period" spans the years between menarche (onset of menstruation) and menopause, when menstruation ceases.
Of the women studied with a shorter reproductive period (32.6 years or less), 16 percent (53 of 333 individuals) developed dementia. In the group of women who were fertile a longer period (38 years or more), 24 percent (88 of 364) developed dementia. The difference was thus 8 percentage points.
The study shows that risk for dementia and Alzheimer's disease increases successively for every additional year that the woman remains fertile. The association was strongest for those with dementia onset after age 85, and the effect was most strongly associated with age at menopause.
These results persisted after adjustment for other factors with an influence, such as educational attainment, physical activity, BMI, smoking, and cardiovascular disease. On the other hand, no association was found between dementia risk and age at menarche, number of pregnancies, duration of breastfeeding, or exogenous estrogen taken in the form of hormonal replacement therapy (HRT) or oral contraceptives.
Several studies have investigated how estrogen in the form of HRT affects dementia risk. Some studies show that dementia risk falls and others that it rises, especially in women who take estrogen late in life.
In the current study Jenna Najar has, instead, investigated the long-term association between factors related to endogenous estrogen and dementia.
"What's novel about this study, too, is that we've had access to information about several events in a woman's life that can affect her estrogen levels. Examples are pregnancies, births, and breastfeeding. Being pregnant boosts estrogen levels tremendously; then they decline once the baby is born, and if women breastfeed the levels fall to extremely low levels. The more indicators we capture, the more reliable our results are," Najar says.
Ingmar Skoog, professor of psychiatry at Sahlgrenska Academy, University of Gothenburg and head of AgeCap, led the study.
"The varying results for estrogen may be due to it having a protective effect early in life but being potentially harmful once the disease has begun."
At the same time, Skoog points out that the duration of women's fertile periods is one risk factor for dementia among many.
Most women whose menopause is delayed do not develop dementia because of this factor alone. However, the study may provide a clue as to why women are at higher risk than men for dementia after age 85, the most common age of onset. Alzheimer's disease, on the other hand, starts developing some 20 years before symptoms of the disorder become apparent.
"Most people affected are over 80 and female," Najar says.
"As a result of global ageing, the number of people affected by dementia will increase. To be able to implement preventive strategies, we need to identify people with an elevated risk of dementia."
https://www.sciencedaily.com/releases/2020/09/200917105419.htm
Projected doubling of Americans living with dementia
Women are at much greater risk and shoulder the majority of costs
October 29, 2019
Science Daily/Milken Institute
The number of Americans living with Alzheimer's disease or other dementias will double to nearly 13 million over the next 20 years, according to the new Milken Institute report "Reducing the Cost and Risk of Dementia: Recommendations to Improve Brain Health and Decrease Disparities."
Milken Institute research estimates that by 2020, roughly 4.7 million women in the US will have dementia, accounting for nearly two-thirds of all people living with the condition.
The number of both women and men living with dementia is projected to nearly double by 2040, with the number of women projected to rise to 8.5 million, and the number of men expected to reach 4.5 million (up from 2.6 million in 2020), according to the report, which was released at the 2019 Milken Institute Future of Health Summit in Washington, D.C.
Over the next 20 years, the economic burden of dementia will exceed $2 trillion, with women shouldering more than 80 percent of the cumulative costs.
"Longer lifespans are perhaps one of the greatest success stories of our modern public health system," explains Nora Super, lead author of the report and senior director of the Milken Institute Center for the Future of Aging. "But along with this success comes one of our greatest challenges. Our risk of developing dementia doubles every five years after we turn 65; by age 85, nearly one in three of us will have the disease."
"With no cure in sight, we must double down on efforts to reduce the cost and risk of dementia," she added. "Emerging evidence shows that despite family history and personal genetics, lifestyle changes such as diet, exercise, and better sleep can improve health at all ages."
In collaboration with partners such as UsAgainstAlzheimer's, AARP and Bank of America, Super and her co-authors, Rajiv Ahuja and Kevin Proff, have developed detailed recommendations and goals for policymakers, businesses, and communities to improve brain health, reduce disparities, and ultimately change the trajectory of this devastating disease.
1) Promote strategies to maintain and improve brain health for all ages, genders, and across diverse populations
2) Increase access to cognitive testing and early diagnosis
3) Increase opportunities for diverse participation in research and prioritize funding to address health disparities
4) Build a dementia-capable workforce across the care continuum
5) Establish services and policies that promote supportive communities and workplaces for people with dementia and their caregivers
"As this important new report shows, dementia is one of the greatest public health challenges of our time," said Sarah Lenz Lock, SVP, Policy & Brain Health at AARP. "It also demonstrates that we have the power to create change, whether by helping consumers maintain and improve their brain health, advancing research on the causes and treatment of dementia, or supporting caregivers who bear so much of the burden of this disease. We at AARP look forward to working with the Milken Institute and other key partners to achieve these goals."
"Brain health broadens the fight against Alzheimer's to include everyone and is the key to defeating stigma, increasing early detection, speeding up research -- and ending this disease," said Jill Lesser, a founding board member of UsAgainstAlzheimer's. "This new look by the Milken Institute offers important recommendations and actions to help move us to an optimal system of brain health care in this country."
Among the breakthrough findings, new data have "unveiled key discoveries about the differences between men's and women's brains, and how they age. Moreover, women typically take on greater caregiver responsibilities than men. Women caregivers are more likely to be impacted financially and leave their jobs or miss work to care for a family member. And research demonstrates that spousal caregivers may be at a higher risk of cognitive impairment or dementia than non-caregivers."
"With this research, the Milken Institute has taken an important step to better understand the impacts of dementia on diverse populations," said Lorna Sabbia, Head of Retirement and Personal Wealth Solutions, Bank of America. "This study, together with our own research on life stages, women, health and wellness, plays a critically important role in our efforts to educate and provide guidance to individuals and families throughout their financial lives."
https://www.sciencedaily.com/releases/2019/10/191029084315.htm
Calcium supplements linked to dementia risk in women with certain health conditions
August 17, 2016
Science Daily/American Academy of Neurology
Calcium supplements may be associated with an increased risk of dementia in older women who have had a stroke or other signs of cerebrovascular disease, according to a new study.
Cerebrovascular disease is a group of disorders that affect blood flow in the brain. These diseases, including stroke, are the fifth leading cause of death in the United States and increase the risk of developing dementia.
"Osteoporosis is a common problem in the elderly. Because calcium deficiency contributes to osteoporosis, daily calcium intake of 1000 to 1200 mg is recommended. Getting this recommended amount through diet alone can be difficult, so calcium supplements are widely used," said study author Silke Kern, MD, PhD with the University of Gothenburg in Sweden. "Recently, however, the use of supplements and their effect on health has been questioned."
The study involved 700 dementia-free women between the ages of 70 and 92 who were followed for five years. Participants took a variety of tests at the beginning and end of the study, including tests of memory and thinking skills. A CT brain scan was performed in 447 participants at the start of the study.
Scientists also looked at the use of calcium supplements in the participants and whether they were diagnosed with dementia over the course of the study. A total of 98 women were taking calcium supplements at the start of the study and 54 women had already experienced a stroke. During the study, 54 more women had strokes, and 59 women developed dementia. Among the women who had CT scans, 71 percent had lesions on their brains' white matter, which is a marker for cerebrovascular disease.
The study found that the women who were treated with calcium supplements were twice as likely to develop dementia than women who did not take supplements. But when the researchers further analyzed the data, they found that the increased risk was only among women with cerebrovascular disease. Women with a history of stroke who took supplements had a nearly seven times increased risk of developing dementia than women with a history of stroke who did not take calcium supplements. Women with white matter lesions who took supplements were three times as likely to develop dementia as women who had white matter lesions and did not take supplements. Women without a history of stroke or women without white matter lesions had no increased risk when taking calcium supplements.
Overall, 14 out of 98 women who took supplements developed dementia, or 14 percent, compared to 45 out of 602 women who did not take supplements, or 8 percent. A total of six out of 15 women with a history of stroke who took supplements developed dementia, compared to 12 out of 93 women with a history of stroke who did not take supplements. Among the women with no history of stroke, 18 out of 83 who took supplements developed dementia, compared to 33 out of the 509 who did not take supplements.
"It is important to note that our study is observational, so we cannot assume that calcium supplements cause dementia," said Kern. The author also noted that the study was small and results cannot be generalized to the overall population, and additional studies are needed to confirm the findings.
Kern noted that calcium from food affects the body differently than calcium from supplements and appears to be safe or even protective against vascular problems.
https://www.sciencedaily.com/releases/2016/08/160817171555.htm