[Association of decreased external pulmonary function with cognitive impairments]

To examine the association between the basic indicators of external respiratory function (ERF) and cognitive impairments (CIs).

The materials of a population-based cross-sectional study were used in the investigation; a representative sample consisted of 3818 men and women aged 45-69 years. Forced expiratory volume in the first second (FEV1), the ratio of FEV1 to forced vital capacity (FVC) were determined to assess ERF. CIs were evaluated using the 10-word test described by A.R. Luria, Cog-sum indices (the sum of correctly reproduced words with 3 attempts), and Cog-mean=Cog-sum/3.

In patients with an FEV1/FVC <70%, the probability of a Cog-sum of <20 scores was twice higher than in those with an FEV1/FVC ≥70%; in patients with an FEV1 <80%, the probability of a Cog-sum of <20 scores was also 2 times higher than in those with an FEV1 ≥80%. Multiple regression analysis revealed no significant associations between Cog-sum index and smoking index, body mass index, and blood pressure. Cog-sum was inversely related to age and directly related to FEV1 and female sex. Binary logistic regression analysis showed that gender, age, and FEV1 were statistically significant variables. The relative risk of a Cog-sum of <20 that was 1.7 times higher in the men than in the women, 1.8 times higher in the patients with an FEV1 <80% than in those with an FEV1 ≥80% (model 1), 1.7 times higher in the patients with an FEV1/FVC <70% than in those with FEV1/FVC ≥70% (model 2) increased with age.

The decrease in the basic indicators of ERF (FEV1, FEV1/FVC) is an independent predictor of CIs.