Asthma comes as a common disease affecting a wide range of populations and remaining a major public health concern across the globe. Respiratory symptoms are closely related to their prognosis, which is directly related to lung function. But this association on a long-term basis remains inconceivable for many.

So a population-based cohort of males and females with asthma, meaningfully describes the association of the type and number of respiratory symptoms with FEV1 and FEV1 decline in individuals with asthma. Valid measurements of FEV1 were carried out during the enrollment and the follow-up period of the participating individuals. 

Respiratory symptoms (recurrent wheeze, dyspnea, longstanding cough and productive cough) were analyzed in relation to FEV1 during enrollment and the annual decline in FEV1 were recorded. It was then both unadjusted and adjusted for other potentially associated factors by linear regression.

The observations of the study were as follows-

• Recurrent wheeze and dyspnea were associated with lower FEV1 at study entry and follow-up in both the sexes.
• Productive cough was associated with lower FEV1 only at follow-up in both the sexes.
• Type of symptoms and annual decline in FEV1 showed no association.
• Adjusted analyses, in women, revealed a significant association between recurrent wheeze and lower FEV1 both at study entry and follow-up.
• The association between a higher number of symptoms with lower FEV1 both at study entry and follow-up were present for both sexes and remained after adjustment. 

Thus, it was concluded that recurrent wheeze, in particular, and an increased number of respiratory symptoms are associated with a lower lung function also in the long haul among both the genders with asthma.

BermúdezBarón N, Lindberg A, Stridsman C, Andersson M, Hedman L, Vikjord SA, Kankaanranta H, Lundbäck B, Rönmark E, Backman H. Among respiratory symptoms, wheeze associates most strongly with impaired lung function in adults with asthma: a long-term prospective cohort study. BMJ Open Respir Res. 2021 Jul;8(1):e000981. doi: 10.1136/bmjresp-2021-000981. PMID: 34281917.