ABERDEEN, UK—Are children who wheeze during upper respiratory infections (URIs) at increased risk of lung dysfunction? The question has been argued for decades. In the 1950s and early 1960s, this type of wheezing was considered to be “wheezy bronchitis,” a disorder distinct from asthma. By the late 1960s, though, it was reclassified as a type of asthma, due to physicians’ fear of undertreating that disease in children.

Since then, studies have suggested that individuals who wheezed as children may not be at increased risk for asthma later in life. However, a recent follow-up of participants in a 1964 school survey in Aberdeen, United Kingdom, found that adults who wheezed during URIs as children, while having experienced no decline in lung function in 1989, had a marked decrease in lung function 12 years later.[1]

When the subjects who were initially studied in 1964 were reevaluated in 1989, those who had wheezed during URIs had normal lung function. To see if this group maintained their lung function, Graham Douglas, BSc, MB, ChB, FRCP, and colleagues conducted a follow-up study in 2001.

One hundred seventy-seven of the original participants—46 with childhood asthma, 65 with childhood wheezing, and 66 with no symptoms—were available for follow-up. All participants were interviewed; in addition, peak flow measurements were performed, and FEV1 and forced vital capacity (FVC) were measured.

LUNG FUNCTION DECLINE IN WHEEZING GROUP

The reported severity of symptoms differed markedly among the three groups. The adults who had had childhood asthma had the highest incidence of phlegm-producing cough, wheezing that interfered with routine activities, and hospital admissions for chest problems during the past 10 years. They also had significantly lower FEV1 than did the other two groups.

However, the adults who had wheezed during URIs as children had markedly lower FEV1 than did those who had been asymptomatic as children, and they were more likely to have been hospitalized for chest problems. Among the adults who had wheezed as children, the decline in lung function between 1989 and 2001 was comparable to that seen in those with childhood asthma. The authors speculated that this decline could be a precursor to chronic obstructive pulmonary disease later in life.

The literature has yielded conflicting results regarding long-term lung function in adults who had wheezed as children. Some studies show no difference from healthy controls, whereas others suggest reduced lung function with age, explained Dr. Douglas, a Consultant Physician at the Aberdeen Royal Infirmary in Scotland. Dr. Douglas believes that his study supports the contention that childhood wheezing during URIs is distinct from asthma and that children with such wheezing are at risk for a more rapid decline in lung function as adults. But his study was unable to predict which children with wheezing would develop problems as adults.

Interestingly, he and his colleagues had also previously found that male offspring of subjects in the childhood wheezing group had lower FEV1 and FVC than did the offspring of those in the childhood asthma or asymptomatic groups. This suggests that heredity may play a part in childhood wheezing during URIs.

—Gale Jurasek