THE ESSENTIAL
- The increase in nicotine levels is associated with a 2.3 minute increase in the time spent with oxygen saturations below 90%.
- For every cigarette a person smokes, the risk of having “dangerously low” oxygen levels increases.
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November is Tobacco Free Month, an operation that aims to raise awareness against the harmful effects for smokers and to support those who wish to quit. Tobacco use is not trivial and kills nearly 75,000 people each year. In a first such study, Australian scientists from Heart Research Institute (HRI) have linked the amounts of nicotine in the blood to the length of time smokers have less oxygen while they sleep. They presented their results on October 17 in the journal ESC Heart Failure.
Quantifying the effects of tobacco
The researchers found that the increase in nicotine levels was associated with a 2.3 minute increase in the time spent with oxygen saturations below 90%. This means that for every cigarette a person smokes, the risk of having “dangerously low” oxygen levels increases. “We know that smoking is bad for the heart – it’s one of the main risks of a heart attack – and although smoking is known to reduce the level of oxygen in the blood, the interaction of smoking with apnea sleep has not been quantified, said Dr. John O’Sullivan, principal investigator of the study. Using blood concentrations of the main metabolite of nicotine, we were able for the first time to quantify the effect of smoking on oxygen levels at night in people with sleep apnea..”
The 90% threshold is important because one of the markers of sleep apnea severity is the time spent with oxygen saturation below 90%. At these levels, the throat and upper airways are partially or completely blocked during sleep, causing short periods of breathing stoppage. “People who spend more time with less than 90 percent oxygen saturation end up having more cardiovascular deaths than people who don’t”Added John O’Sullivan.
Track blood metabolite levels
To link sleep apnea and congestive heart failure, researchers used hundreds of small molecules, called metabolites, to understand this interaction. The team studied metabolites and lipids in nearly 3,500 people included in two American cohorts. “Accurate measurement of disease combined with blood metabolite levels is much more accurate than self-reported questionnaires, this is one of the strengths of this study”, Continued the lead author of the study.
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