A new study published in the journal Alzheimer’s & Dementia suggests that the menopausal transition is a critical time for women and their doctors to focus on heart health, which in turn protects brain health. The study, added to existing evidence, revealed the link between cardiovascular risk factors during the menopausal transition and cognitive function later in life. The researchers found that among the different types of cardiovascular fat, PVAT (thoracic perivascular adipose tissue) is located the closest to brain circulation and is linked to better whole-body metabolism and lower inflammation markers.
“It is shocking to know that two-thirds of Americans with Alzheimer’s disease are women. The most common modifiable risk factor for dementia is cardiovascular disease, and, interestingly, a woman’s risk for cardiovascular disease increases after menopause. So the next logical step was to see if there was a link between cardiovascular risk factors related to the menopause transition – such as the type of cardiovascular fat a woman has – and her cognitive function later in life,” said Meiyuzhen (Chimey) Qi, Ph.D. candidate in epidemiology at Pitt Public Health and first author of the study.
The scientists used the long-running Study of Women’s Health Across the Nation (SWAN) and its supplementary study, SWAN Cardiovascular Fat, to investigate the concept. SWAN tracked the progress of several women in their forties as they underwent the menopausal transition, with 531 individuals with an average age of 51 scanned to learn about the fat around their hearts and veins. They were then evaluated for 16 years, with various cognitive tests administered along the way.
Cardiovascular fat has three types: epicardial adipose tissue, paracardial adipose tissue, and thoracic perivascular adipose tissue. EAT and PAT are often poorer quality “white” fats that the body retains, but thoracic PVAT is a better quality “brown” fat that the body easily transforms to energy. The density of fat in the scans was used as a measure of fat quality by the researchers.
The researchers assessed how the quantity and quality of cardiovascular fat during midlife are interrelated with cognitive function as women age. A greater volume of thoracic PVAT during midlife was related to stronger long-term memory later in life, while higher density of thoracic PVAT – probably reflecting lower quality white fat – was linked to declining working memory.
“This is an association. We cannot say with any certainty that higher or lower quality cardiovascular fat causes Alzheimer’s disease – but it is a tantalizing clue that makes sense,” said senior author Dr Samar El Khoudary, professor of Epidemiology at Pitt Public Health. “Of the different types of heart fat, PVAT is closest to brain circulation and brown fat is linked to better whole-body metabolism and lower markers of inflammation.”
Women usually experience vascular or fat tissue inflammation during the menopause transition, which may manifest as thoracic PVAT with higher density, meaning it is of lower quality. Previous studies have found that vascular inflammation promotes plaque formation, and inflamed fat tissue has abnormal secretion of cell signaling molecules, which predispose people to cognitive decline.
The study was limited to white and black women, so further research will be required to establish whether the findings apply to women of other races and ethnicities, as well as to men. Also, researchers need to determine if the type of cardiovascular fat actually causes cognitive decline or if efforts to modify the quality of cardiovascular fat – such as taking anti-inflammatory drugs – can stave off dementia.
“That said, I believe our study is more evidence that taking care of your heart helps take care of your brain and that menopause is a particularly sensitive time for heart as well as brain health,” El Khoudary said. “So staying active and regularly doing cardiovascular exercises that get your heart pumping, as well as eating a healthy diet and keeping up with doctor’s appointments, are all especially important at midlife. Protecting your heart during the menopausal transition may be protecting your brain in the future.”
