When a person is suspected of having heart disease, he or she would normally be asked to undergo a procedure called angiogram or go for the latest CT scan known as ’64-sliece CT so as to ascertain whether treatment is needed for the potential patient..
However, there is a new way to identify a woman’s heart disease risk by analyzing the nicotine content of her toenail clippings. This new means was revealed in June 2008 in the American Journal of Epidemiology by researchers from the University of California in San Diego.
For the 62,641 women participating in the Nurses' Health Study, researchers correlated their nicotine content in toenail clippings collected in 1982 to the risk of being diagnosed with heart disease between 1984 and 1998.
Women, who were in the top fifth for toenail nicotine content, were thinner, less active, heavier drinkers, more likely to have high blood pressure or diabetes, and a family history of heart attack, comparing with those with lesser nicotine in their toenails. Furthermore, the nicotine content found in the toenails for the 905 women, who had been diagnosed with heart disease, were twice as much on average than those similar women without heart disease. After adjusting for other risk factors, the women in the top fifth for toenail nicotine were nearly 4 times more likely to have heart disease compared to those in the bottom fifth.
The prevailing biomarkers of cigarette smoke exposure such as the amount of cotinine (a nicotine breakdown product) in urine or saliva could only reflect exposure within the past few days. As toenails grow slowly, they may offer a longer-term, more stable estimate of a person's total level of exposure to tobacco smoke.
Toenail analysis could become a useful test to identify high-risk individuals in the future, especially in circumstances where smoking history is unavailable or is subject to bias. Such analysis may also aid our understanding of other tobacco-related illnesses.
As the current study involved only female participants, perhaps future studies should consider including male participants to find out whether similar analysis could be applied to men as well.