The Vital Capacity Is Vital: Epidemiology and Clinical Significance of the Restrictive Spirometry Pattern

Abstract

Epidemiologic research has revealed a substantial portion of the general population with abnormal spirometry results that are characterized by decreased FEV1 and FVC but a preserved FEV1/FVC ratio. This restrictive spirometry pattern (RSP) is inconsistently defined in the literature and not well addressed by current guidelines; there is an accumulating body of evidence, however, that RSP is prevalent to a similar degree as airflow obstruction. Genetic andother risk factors for RSP, such as inhalational injuries and early life exposures, continue to be actively described. Although itseems that RSP is closely associated with themetabolic syndrome, diabetes, and systemic inflammation, it is not a simple marker of obesity. RSP isassociated with adverse cardiovascular outcomes, as wellas mortality, and it may be an underappreciated cause of functional impairments and respiratory symptoms. Improvement in outcomes in this population will require thatclinicians have an appreciation for thesignificance of this spirometry pattern; additional research into the clinical and radiologic phenotype ofthese subjects is alsoneeded. This article provides anoverview of the recent developments in our understanding of this prevalent and highly morbid spirometry pattern.