Abstract
The full text of this article is freely and openly accessible from the following: https://www.bmj.com/content/302/6768/89.full.pdf
When an individual inhales cigarette smoke, heart rate rises and blood pressure increases. These physiologic responses are due to the effects of nicotine. However, many studies have reported lower than average blood pressures in adults who smoke than in nonsmokers. A total of 839 children in Dunedin, New Zealand were evaluated biannually, between the ages of 11 and 15 years, regarding their smoking history, cardiovascular fitness, exercise tolerance, and body size. Blood pressures were obtained at rest; before exercise, while seated on a bicycle; during a standard six-minute bicycling test; immediately after six minutes of cycling; and following five minutes' recovery. The study population consisted of five groups of children who were defined in terms of their smoking history. Data were evaluated when the participants were 15 years old. Among the groups, blood pressure differences during exercise were not significant. However, significant differences in blood pressure readings were observed after recovery and, although these differences were small, they remained significant after adjustment for height, weight, and sex. The results were similar in direction and magnitude to those noted in adult smokers, and are suggestive of a smoking-related effect on blood pressure among even young, occasional smokers. That the differences were not evident four years earlier suggests that they were caused by smoking.