Environmental, Clinical Factors Associated With Reduced Forced Vital Capacity

A physician examining a patient's breathing
A physician examining a patient’s breathing
Investigators examined associations between reduced FVC and various health variables and risk factors in adults aged 40 years and older living in urban Tunisia.

Aging, height, and poor socioeconomic status are linked with reduced forced vital capacity (FVC) in the adult population in Tunisia, according to survey findings published recently in BioMed Central Pulmonary Medicine.

Research indicates that a reduction in forced vital capacity may be associated with conditions such as cardiovascular diseases, metabolic syndrome, and obesity, and may be a risk factor for higher mortality, said authors of the current study. Because of the mortality risk associated with reduced FVC, and because of the lack of data on FVC in the Tunisian population, researchers there sought to identify the incidence of reduced FVC in community-based sample of Tunisians as well as potential risk factors for reduced FVC in this population.

The researchers conducted a cross-sectional survey using data from the Tunisian Burden of Obstructive Lung Disease (BOLD) study that included 661 adults at least 40 years of age living in the urban area of Sousse. Reduced FVC was defined below the lower limit of normal using Global Lung Function Initiative 2012 equations (GLI 2012) and National Health and Nutrition Examination Survey (NHANES) values. Investigators found reduced FVC in slightly more than 25% of the study group when compared with NHANES values for White people in the US and slightly more than 14% using the GLI 2012 equations.

When the investigators compared individuals with reduced FVC to those with normal FVC, they found the reduced FVC group to be significantly older and taller, with a significantly lower body mass index, more respiratory symptoms, and a greater prevalence of hypertension and heart disease. In addition, study authors said their multivariable analysis suggested that “reduced FVC was essentially driven by exposure to biomass smoke for heating, a number of schooling years lower than or equal to 6 years, a childhood history of hunger for a lack of money, aging and height.”  

Overall, said the investigators, the study revealed a high prevalence of reduced FVC in this Tunisian population sample, and indicated that “the potential contribution of environmental factors to reduced FVC should be considered rather than assuming that having a small lung volume is accounted for solely by genetic factors.”


Hsan S, Lakhdar N, Harrabi I, Zaouali M, Burney P, Denguezli M. Reduced forced vital capacity is independently associated with, aging, height and a poor socioeconomic status: A report from the Tunisian population-based BOLD study. BMC Pulm Med. Published online July 11, 2022. doi:10.1186/s12890-022-02062-3