Aging is a global phenomenon throughout the body, a cascade of increasing complexity that starts with comparatively simple causes. Each of these distinct causes contributes to many age-related conditions, and all interact with one another. So on the one hand it is easy to find correlations between different aspects of aging - it would be surprising if that wasn't the case. On the other hand, different aspects of aging in different organs will turn out to share the same subset of important root causes, so it should be also possible to identify correlations that stand apart from the rest of the progression of aging.
Intrinsic skin aging and cardiovascular disease are two such linked manifestations of aging. Both are driven by loss of flexibility of tissues. Skin and blood vessel walls suffer issues due to the very similar accumulation of cross-links in the extracellular matrix and the presence of senescence cells and their inflammatory signaling. In skin, the loss of elasticity leads to wrinkles as its most evident manifestation. In the cardiovascular system, the consequences are more severe: failure of feedback mechanisms controlling blood pressure; remodeling of the heart and blood vessels; pressure damage to sensitive tissues; and ultimately the fatal structural failure of a major blood vessel - a stroke or heart attack.
The authors of the current prospective study investigated a different visible marker of age - horizontal forehead wrinkles - to see if they had any value in assessing cardiovascular risk in a group of 3,200 working adults. Participants, who were all healthy and were aged 32, 42, 52, and 62 at the beginning of the study, were examined by physicians who assigned scores depending on the number and depth of wrinkles on their foreheads. A score of zero meant no wrinkles while a score of three meant "numerous deep wrinkles."
The study participants were followed for 20 years, during which time 233 died of various causes. Of these, 15.2% had score two and three wrinkles. 6.6% had score one wrinkles and 2.1% had no wrinkles. The authors found that people with wrinkle score of one had a slightly higher risk of dying of cardiovascular disease than people with no wrinkles. Those who had wrinkle scores of two and three had almost 10 times the risk of dying compared with people who had wrinkle scores of zero, after adjustments for age, gender, education, smoking status, blood pressure, heart rate, diabetes, and lipid levels.
Furrows in your brow are not a better method of evaluating cardiovascular risk than existing methods, such as blood pressure and lipid profiles, but they could raise a red flag earlier, at a simple glance. The researchers don't yet know the reason for the relationship, which persisted even when factors like job strain were taken into account, but theorise that it could have to do with atherosclerosis, or hardening of the arteries due to plaque build-up. Atherosclerosis is a major contributor to heart attacks and other cardiovascular events. Changes in collagen protein and oxidative stress seem to play a part both in atherosclerosis and wrinkles. Also, blood vessels in the forehead are so small they may be more sensitive to plaque build-up meaning wrinkles could one of the early signs of vessel ageing.