Dr Veena Aggarwal
Results of the Study of Womens Health Across the Nation (SWAN) cardiovascular fat ancillary study published in the journal Alzheimer’s and Dementia suggest that vascular fat composition at mid-life may be an indicator of future cognitive impairment.1
Researchers from across the United States collaborated in this multicenter study to investigate the association between quantity (measured as volume of fat) and quality (density of fat) of cardiovascular fat and cognition in middle-aged women in addition to assessing the volume and radiodensity of cardiovascular fat. A total of 531 women with a mean age of 51 years were recruited for the study. With the help of CT scans and tests, fat density was calculated at three different locations – epicardial (inside the sac surrounding the heart), paracardial (outside the sac surrounding the heart) and thoracic perivascular around the descending aorta. The participants were also frequently tested for cognition over 16 years of follow-up.
The presence of a high volume of thoracic perivascular adipose tissue (brown fat) during midlife was found to be associated with greater future episodic memory (memory of events and experiences). On the other hand, higher radiodensity of the thoracic perivascular adipose tissue (indicative of presence of high levels of white fat) had a significant association with worsening future episodic memory as well as lesser working memory (short-term memory, which helps in daily processing, utilizing and remembering information).
The thoracic perivascular adipose tissue (PVAT) is similar to brown fat, which protects against vascular inflammation and is associated with better metabolic health since it is readily converted to energy. White fat, conversely, is pro-inflammatory causing vascular inflammation, which predisposes to Alzheimer’s disease; it is the fat which is stored in the body, mainly in the thighs, hips and abdomen. The epicardial and paracardial fat are white fat.
This study has shown that it is the thoracic PVAT, and not epicardial and paracardial fat, which is linked to loss of memory later on in life in mid-life women. According to the researchers, their study only shows an association and does not establish cause and effect relationship. This study also highlights the need for middle-aged women to be aware of the risks of excess body fat and take all measures to reduce their risk.
Reference
- Meiyuzhen Qi, et al. The quantity and quality of cardiovascular fat at mid-life and future cognitive performance among women: The SWAN cardiovascular fat ancillary study. Alzheimers Dement. 2023 May 22. doi: 10.1002/alz.13133.
Dr Veena Aggarwal is Consultant Womens’ Health, CMD and Editor-in-Chief, IJCP Group & Medtalks Trustee, Dr KK’s Heart Care Foundation of India