Why Are Women More Likely To Develop Dementia Than Men
We don’t fully understand why women are more likely to develop Alzheimer’s disease than men, but one of the main theories is to do with the hormone oestrogen.
Whilst both men and women produce oestrogen, its the main female sex hormone and so women usually have more of it. When women go through menopause, their bodies stop producing as much oestrogen.
On the other hand, men continue to produce testosterone, the male sex hormone, throughout their lives. Testosterone is actually converted into oestrogen inside brain cells. This means that women who have been through menopause have lower levels of oestrogen in their brain than men of the same age.
As Alzheimer’s disease is more common in women after the menopause, it is possible that oestrogen plays a role in protecting the brain from the damage caused by Alzheimers, and that this protective effect is lost when oestrogen levels are decreased.
Down Sampling Sensitivity Analysis
Given the imbalance in the proportion of AD cases in the female samples compared to male samples, we down sampled our brain and blood datasets to assess whether our results were primarily driven by differences in statistical power between males and females. Specifically, we performed 100 iterations of down sampling. In each iteration, we down sampled the female samples in our dataset such that the total number of AD cases and controls was the same in the male and female groups. For example, the number of cases and controls in the original dataset and down sampled dataset for the brain data are presented below:
In each iteration, we calculated the number of differentially expressed genes in males and females. We then randomly selected one iteration to repeat all the other analyses, including functional enrichment analysis, network analyses, SVM-based classification and cell type deconvolution, that were performed on the dataset without down sampling to assess the contribution of statistical power to our findings.
Dementia Risk Factors For Men And Women
Prevalence and average values for risk factor measures for men and women in each cohort at Wave 1 and Wave 4 are shown in Fig. and in Table of the Online Appendix. Notable sex differences were evident for baseline measures of head injury , overweight , vigorous activity and hypertension . The proportion of men and women with hypertension increased with age but men consistently had higher rates than women. There was a notable increase in diabetes with age and wave, especially for men . There was a notable increase in adults reporting taking blood pressure medication , and a notable increase in rates of cancer with age .
Prevalence of dementia risk factors at wave 1 and wave 4 in men and women in three cohorts.
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Network Analysis In Whole Blood Identifies A Stronger Disease Signature In Females
We identified five AD-associated modules in females and zero AD-associated modules in males that met the significance threshold and were either positively or negatively correlated with case/control status. Among the modules in female samples, three modules including a 483-gene module , a 129-gene module and 153-gene module were upregulated in AD. Two modules including a 270-gene module and 119-gene module were downregulated in AD . No modules with significant APOE 4:disease interaction effect were found in female or male network analyses from the blood datasets.
Enrichment analysis of disease-associated modules using the 2019 KEGG Human pathway database revealed pathways relevant to AD that were consistent with those identified in the single gene analysis . For example, upregulated modules in females were strongly enriched for innate immune system activity, neutrophil degranulation, CSF signaling, IL2 signaling, and cytokine signaling. Consistent with single gene analyses, downregulated modules in females were enriched for metabolic processes including metabolism of RNA and metabolism of amino acids .
For a full list of genes in each module, including hub genes, please refer to Supplementary Tables S16S17).
Is Alzheimers More Common In Males Or Females Uk
At Alzheimers Research UK we know: Dementia affects over 850,000 people in the UK and 44 million worldwide. It is estimated that 61% of people with dementia are women and 39% are men. This is likely to reflect the fact that women live longer than men and age is the biggest known risk factor for the condition.
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Does Heart Health Play A Role In Dementia Risk
We know that what is good for the heart is good for the head. Improving heart health seems to be a good way to lower dementia risk. The health of a heart affecting dementia risk might also be linked to sex. For example, high blood pressure in midlife is believed to increase risk in women but not men, even though it is more common in men.
Professor Patrick Kehoe is an Alzheimers Society funded researcher based at University of Bristol. He says:
‘It is possible that the complex relationship of oestrogen to the renin angiotensin system, which regulates blood pressure and has roles in cognitive function, influences a womans risk of developing Alzheimers. Following menopause with the influence of oestrogen on this system a woman is at greater risk of high blood pressure and so perhaps also dementia, but we need to test this in more detail.
Who Is More Prone To Dementia
The greatest known risk factor for Alzheimers and other dementias is increasing age, but these disorders are not a normal part of aging. While age increases risk, it is not a direct cause of Alzheimers. Most individuals with the disease are 65 and older. After age 65, the risk of Alzheimers doubles every five years.
Research Shines Light On Why Women More Likely To Develop Alzheimer’s
Protein tau may spread more rapidly in female brains than males, adding to range of factors
The reason women appear to be at greater risk of developing Alzheimers disease than men might be due to a number of genetic, anatomical and even social influences, researchers have suggested.
Recent figures show about 65% of those with living with dementia in the UK are women, with a similar statistic seen in the US for Alzheimers disease, while dementia is the leading cause of death for women in England. Alzheimers disease is only one of the types of dementia, but the most common form.
While one explanation is that dementia risk increases with age, and women have longer life expectancies than men, new research suggests there might be more to the matter, including that protein tangles found within neurons and linked to Alzheimers disease might spread differently in womens brains than mens.
The study, presented at the Alzheimers Association International Conference in Los Angeles by researchers from Vanderbilt University and which has not yet been peer-reviewed, used scans from a method called positron emission tomography. That allowed them to look at the way clumps of a protein called tau were spread in the brains of 123 men and 178 women without cognitive problems, as well as 101 men and 60 women with mild cognitive problems although not yet diagnosed with Alzheimers disease. Cognitively normal older people often have small amounts of tau in certain areas of their brain.
Can Alzheimer’s Disease Be Prevented
As the exact cause of Alzheimer’s disease is not clear, there’s no known way to prevent the condition.
But there are things you can do that may reduce your risk or delay the onset of dementia, such as:
- staying physically fit and mentally active
These measures have other health benefits, such as lowering your risk of cardiovascular disease and improving your overall mental health.
Read more about preventing Alzheimer’s disease.
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Oestrogen And The Brain
Oestrogen affects the brain in several different ways, some of which researchers think could help explain how it could protect against Alzheimer’s. For example, one study on rats has found that oestrogen helps to increase the number of connections in a particular area of the brain. This brain area, called the hippocampus, is important for memory and certain types of learning, which are both affected by Alzheimer’s disease. Oestrogen can also affect the way chemicals such as serotonin, acetylcholine and dopamine are used to send signals throughout the brain. Some of the symptoms of Alzheimer’s disease are linked to problems with the acetylcholine signalling system, which could be connected to .
Apoe4 Affects Women And Men Differently
We now know of a gene that’s linked to Alzheimer’s, called Apolipoprotein E , that can help doctors predict if someone will develop the disease later on. So far, we’ve discovered that the ApoE4 gene affects men and women differently. When studying women and men, women with this gene were twice as likely to develop Alzheimer’s than those without the gene. Men with the gene, however, were only slightly more likely to develop the disease.
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Estimation Of Sex Differences In Memory Function And Change Over Time
Women performed better than men on immediate recall and delayed recall, in all cohorts and at each Wave . Longitudinal analyses showed that in the 20 s cohort, there were no sex differences in either immediate or delayed memory change. In the 40 s cohort women improved more over time than men on immediate recall . In the 60 s cohort, rate of decline in immediate recall was faster in women than men .
What You Can Do To Lower Your Risk
We’ve seen that some of the reasons why women are more likely than men to develop Alzheimer’s disease are things we can’t really change â women’s longer lives and certain genetic factors, for example. Some risk factors, however — like not being as physically active as men — you can do something about. Here are a few more:
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How Sex Impacts Dementia Diagnosis
Oestrogen affects how a womans brain grows and functions. Researchers think this might be why women have a better memory for words and verbal items than men. To assess this part of our memory we measures memory of a list of words or a short story.
Women keep these skills even if they have mild memory and thinking problems. The first step in dementia diagnosis is a verbal memory test. This poses a problem for men and women. As women have a strong verbal memory, they tend do well on memory tests, even if they have cognitive problems. This means they are under diagnosed with dementia.
Men are more likely to be incorrectly diagnosed with dementia because their verbal memory skills might not be as strong. At Alzheimers Society, we champion person-centred care. This must begin with a method of diagnosis that takes into account certain factors. These could include things such as cultural background, education, on and off days and sex
Dementia Is More Common Among Women
For years, it was believed that rates of dementia and, more specifically Alzheimers, were due to the fact that women live longer than men. Although women can expect a longer lifespan on average, this gap is beginning to close mens health appears to be improving, whereas womens health is not. As researchers began focusing on additional factors, it became evident that there may be contributing factors that are beyond longevity. Lets put it this way by the time women are 65, they experience a 1 in 6 chance of developing Alzheimers, in comparison to a 1 in 11 chance for men. While focusing on the approximate 5 million Americans who are living with Alzheimers, 3.2 million are women so, its easy to say that rates of dementia are disproportionate between males and females. Why is this occurring? Is there any way to intervene?
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Numbers Of People With Dementia By Gender
The national breakdown of dementia prevalence by gender is shown below. Englands greater population of people leads to the much higher numbers of people with dementia though a similar gender breakdown is seen across the UK.
Dementia also has a greater impact on women as the majority of carers are women.
Gender Differences In Incidence Rates Of Dementia
presents the proportion of men and women diagnosed with any dementia, AD alone, and NAD alone. Of the 3,871 individuals with a dementia diagnosis, 2,325 were diagnosed with AD and 1,546 with another form of dementia. Women were more likely than men to be diagnosed with any dementia and AD whereas NAD was more equally prevalent. Incidence rates of any dementia for men and women were nearly equivalent until the early 80s, but diverged thereafter and significantly diverged between 85 and 90 years of age . Beyond 90, incidence rates for both men and women declined, most likely because of the sparseness of data in old-old age. For AD alone, significant divergence in rates occurred at approximately 80 years of age. Although divergence is visually more prominent at a somewhat younger age , the confidence intervals of the loess lines still overlap . For NAD alone, rates are similar between men and women until greater than 90 years of age, at which point women have significantly higher rates than men despite slight visual differences . Patterns were similar when incidence rates were traced only with clinically diagnosed cases of dementia as well as separately in the cross-sectional census alone and combined longitudinal samples.
Incidence density rates of a) any dementia, b) Alzheimers disease, and c) non-AD dementia per 1000 person-years in men and women twins across late adulthood. Loess smoothing lines were fit using nonparametric local polynomial regression fitting methods.
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Alzheimer’s Study: Men Vs Women
Researchers from Weill Cornell Medicine recruited 121 participants , between the ages 40 and 65 with normal brain function. Participants underwent an extensive intake process plus clinical and neuropsychological examinations, laboratory tests and various brain scans.
After collecting data, researchers assessed specific risk factors — age, education level, APOE status, family history, depression, diabetes, high cholesterol, thyroid disease, post-menopause, smoking, diet, exercise and intellectual activity — and used them to compare Alzheimers disease biomarkers between men and women and to identify risk factors associated with gender-related differences.
Gender And Age Differences And The Trend In The Incidence And Prevalence Of Dementia And Alzheimers Disease In Taiwan: A 7
Susan C. Hu
1Department of Public Health, College of Medicine, National Cheng Kung University, No. 1, University Road, Tainan City 701, Taiwan
2Department of Public Health, College of Public Health, China Medical University, Taichung 404, Taiwan
3Department of Neurology, En Chu Kong Hospital, No. 399, Fuxing Road, Sanxia District, New Taipei City 23702, Taiwan
Dementia has been considered as a public health priority as it commonly leads to increase in terms of disability, mortality, and cost . The most common type of dementia is Alzheimers disease which accounts for nearly 50%70% of dementia in the world . More than 90% of dementia and AD onset occur in individuals aged 65 years and older . However, not all studies have distinguished AD from all type of dementia.
Due to the rapidly ageing population in the world, several studies have reported an increasing trend in the prevalence of dementia and AD over the past decades. Some studies have also reported increased trends in the incidence of dementia or AD over time, while other studies in high-income countries have shown no change or even a decrease in the past decades. These inconsistent results indicate the risk of dementia and AD is variable however, limited nationwide studies on the secular trend of the incidence and prevalence of dementia and AD have been conducted in Asia .
2. Materials and Methods
2.1. Data Sources
2.2.1. Dementia Study
2.2.2. AD Study
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Q Why Are Women At A Higher Risk Of Alzheimers Than Men
Answer: First of all, its been known for a long time that women are more prone to get Alzheimers than men. It was thought to be related to the fact that women live longer, but when they really looked at it, it turns out that people who are the equivalent age, like in their 80s, theres really not a higher proportion of women than men.
There could be multiple reasons, and theres been a lot of hypotheses about why more women have Alzheimers than men. One thing they know from the genetics standpoint is that women who carry the APOE e4 gene and about 20 percent of the population has this in varying degrees are more prone. Theres equal chance of men and women having this gene, but the women who carry it are much more likely to get Alzheimers.
They also know that certain factors make them much more vulnerable to getting the disease. It may be related to estrogen but its unsure just how its related to estrogen. Some of the trials have found that estrogen replacement by itself without progesterone actually made women more vulnerable to Alzheimers. But then again, the timing of the estrogen is important. Its when they get estrogen right as they go into menopause that it seems to mitigate the risk somewhat. Whereas if they take estrogen later in the course of their menopause it doesnt really seen to help. Certain forms of estrogen certainly are worse for women, such as Premarin, which is an older form of estrogen that women used to get.
Some Key Warning Signs That Point To An Alzheimers Diagnosis Include:
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