The global significance of PRISm: how data from low- and middle-income countries link physiology to inflammation

Lung function impairment in relation to cognition and vascular brain lesions: the Rotterdam Study

OBJECTIVE

To investigate the association of chronic obstructive pulmonary disease (COPD) and Preserved Ratio Impaired Spirometry (PRISm) with cognitive performance and presence of vascular brain lesions (VBL).

METHODS

We determined both cross-sectional and longitudinal association of lung function impairment with cognition, as well as cross-sectional association of lung function impairment with VBL, in the general population. Between 2009 and 2014 we included 3,941 participants from the Rotterdam Study with spirometry tests, brain MRI scans and cognition tests, of whom 1815 had follow-up data on cognition.

RESULTS

Our finding indicated that cross-sectionally, participants with PRISm or COPD GOLD2-4 had a worse global cognitive performance. We did not find differences in cognition over time between those with normal spirometry versus those with lung function impairment. In addition, PRISm and COPD GOLD2-4 were associated with a higher prevalence of lacunar infarcts compared to normal spirometry.

CONCLUSIONS

This study suggests that persons with COPD GOLD2-4 or restrictive lung function, defined as PRISm, are characterized by poorer global cognitive function and a higher prevalence of lacunar infarcts.

Trajectory of Preserved Ratio Impaired Spirometry: Natural History and Long-Term Prognosis

RATIONALE

Natural history of Preserved Ratio Impaired Spirometry (PRISm), often defined as FEV1/FVC≥lower limit of normal and FEV1<80% of predicted value, is not well-described.

OBJECTIVE

To investigate natural history and long-term prognosis of PRISm trajectories: persistent PRISm trajectory (individuals with PRISm both as young and as middle-aged); normal-to-PRISm trajectory (individuals developing PRISm from normal spirometry in young adulthood); and PRISm-to-normal trajectory (individuals recovering from PRISm in young adulthood by normalizing spirometry while middle-aged).

METHODS

We followed 1160 individuals aged 20-40 years from the Copenhagen City Heart Study from 1976-83 until 2001-03 to determine their lung function trajectory: 72 had persistent PRISm trajectory, 76 normal-to-PRISm trajectory, 155 PRISm-to-normal trajectory, and 857 had normal trajectory. From 2001-03 until 2018, we determined risk of cardiopulmonary disease and death.

MEASUREMENTS AND MAIN RESULTS

We recorded 198 admissions for heart disease, 143 for pneumonia, and 64 for COPD, and 171 deaths. Compared to individuals with normal trajectory, hazards ratios for individuals with persistent PRISm trajectory were 1.55 (95% CI, 0.91-2.65) for heart disease admission, 2.86 (1.70-4.83) for pneumonia admission, 6.57 (3.41-12.66) for COPD admission, and 3.68 (2.38-5.68) for all-cause mortality. Corresponding hazards ratios for individuals with normal-to-PRISm trajectory were 1.91 (1.24-2.95), 2.74 (1.70-4.42), 6.03 (3.41-10.64), and 2.96 (1.94-4.51), respectively. Prognosis of individuals with PRISm-to-normal trajectory did not differ from those with normal trajectory.

CONCLUSIONS

PRISm in middle-aged individuals is associated with increased risk of cardiopulmonary disease and all-cause mortality, but individuals who recover from PRISm during their adult life are no longer at increased risk.

Lung Function Impairment and the Risk of Incident Dementia: The Rotterdam Study

BACKGROUND

The etiology of dementia may partly be underpinned by impaired lung function via systemic inflammation and hypoxia.

OBJECTIVE

To prospectively examine the association between chronic obstructive pulmonary disease (COPD) and subclinical impairments in lung function and the risk of dementia.

METHODS

In the Rotterdam Study, we assessed the risk of incident dementia in participants with Preserved Ratio Impaired Spirometry (PRISm; FEV1/FVC≥0.7, FEV1 < 80% predicted) and in participants with COPD (FEV1/FVC < 0.7) compared to those with normal spirometry (controls; FEV1/FVC≥0.7, FEV1≥80% predicted). Hazard ratios (HRs) with 95% confidence intervals (CI) for dementia were adjusted for age, sex, education attainment, smoking status, systolic blood pressure, body mass index, triglycerides, comorbidities and Apolipoprotein E (APOE) genotype.

RESULTS

Of 4,765 participants, 110 (2.3%) developed dementia after 3.3 years. Compared to controls, participants with PRISm, but not COPD, had an increased risk for all-type dementia (adjusted HRPRISm 2.70; 95% CI, 1.53-4.75; adjusted HRCOPD 1.03; 95% CI, 0.61-1.74). These findings were primarily driven by men and smokers. Similarly, participants with FVC% predicted values in the lowest quartile compared to those in the highest quartile were at increased risk of all-type dementia (adjusted HR 2.28; 95% CI, 1.31-3.98), as well as Alzheimer's disease (AD; adjusted HR 2.13; 95% CI, 1.13-4.02).

CONCLUSION

Participants with PRISm or a low FVC% predicted lung function were at increased risk of dementia, compared to those with normal spirometry or a higher FVC% predicted, respectively. Further research is needed to elucidate whether this association is causal and how PRISm might contribute to dementia pathogenesis.