Cardiovascular and Functional Consequences of Lung Function Impairment in Northern Thai Agricultural Workers

In low- and middle-income countries, notably in rural agricultural populations exposed to environmental and occupational dangers, respiratory impairment and noncommunicable diseases (NCDs) are major public health issues. This cross-sectional study examined the associations between lung function, functional capacity, and cardiovascular responses to the Six-Minute Walk Test (6MWT) in 137 adults from San Pa Tong District, Northern Thailand. Lung function was assessed using spirometry, and participants were classified accordingly. Hemodynamic parameters, including blood pressure, heart rate, rate-pressure product, and oxygen saturation, were measured before and after the 6MWT. Participants with impaired lung function walked significantly shorter distances (p = 0.004), and walking distance was positively correlated with forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁). Logistic regression confirmed that walking distance independently predicted lung function impairment after adjusting for age and sex. Cardiovascular responses to exercise also varied significantly across demographic subgroups. These findings support the use of the 6MWT as a practical, cost-effective, and scalable method for detecting lung function impairments in resource-limited rural settings. To our knowledge, this is among the first studies to demonstrate the predictive value of the 6MWT for lung function impairment in a Southeast Asian agricultural population.