The association between serum osmolality and lung function among United States adults

¹ Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building, Nottingham City Hospital, Nottingham, NG5 1PB, United Kingdom

	Abstract

The extensive pulmonary vasculature results in the lungs being intimately exposed to circulating blood. As increased serum osmolality may be associated with an increase in pro-inflammatory activity, this has the potential to result in damage to the lungs and reduced lung function. Our objective was to test the hypothesis that increased serum osmolality is associated with lower Forced Expiratory Volume in one second (FEV₁) and Forced Vital Capacity (FVC).

Cross-sectional study of 10,602 participants in the Third National Health and Nutrition Examination Survey aged 17 years or more who had adequate data on all outcomes and exposures.

After adjustment for age, smoking and other confounding factors, increased serum osmolality was inversely associated with both FEV₁ and FVC. A standard deviation increase in serum osmolality was associated with a decrease in both FEV₁ of 19.8ml (95% confidence interval CI; -30.3 to -9.3) and FVC of 35.3ml (95% CI; -47.9 to -22.7). The constituent assays demonstrated a complex relationship with both FEV₁ and FVC.

Increased serum osmolality was associated with decreased FEV₁ and FVC. If causal, this may have implications for our understanding of the processes that are involved in the pathophysiology of the decline in lung function.