What did the media say?
The media reported that measuring the nicotine content of toenail clippings could help predict a woman’s risk of developing heart disease.
What does the research show?
US researchers from Boston and San Diego set out to assess whether levels of nicotine in toenails were a biomarker for coronary heart disease.
They carried out a case controlled study of 62,641 women, aged between 36 and 61, who were part of the Nurses’ Health Study, one of the most definitive long-term epidemiological studies conducted to date on women’s health.
Researchers collected toenail clippings in 1982. Between 1984 and 1998, they recorded 905 diagnosed cases of heart disease, which they then matched with two controls each.
By comparing the levels of nicotine in toenails between the controls and the cases, they identified a statistically significant link between nicotine level and heart disease risk, they said. Women in the top fifth for nicotine content had a three and half times greater relative risk of developing coronary heart disease than those in the lowest fifth.
What did the researchers say?
Toenail nicotine levels are predictive of coronary heart disease among women independent of other risk factors and remained significant even after adjustment for history of cigarette smoking.
What does this mean for nursing practice?
Ellen Mason, cardiac nurse at the British Heart Foundation, said: ‘While this novel study emphasises that smokers are storing up health problems for the future, we already know the habit greatly damages your heart health so we don’t need toenail clippings to tell us this.
‘People using nicotine replacement therapy should not be alarmed by this study as it is the other chemicals inhaled when smoking, such as carbon monoxide that cause the risk of heart disease, not nicotine,’ she said.
American Journal of Epidemiology (2008) 167: 1342-1348