Relative and absolute lung function change in a general population aged 60–102 years

Abstract

Data on longitudinal lung function change in the elderly are scarce. Uncertainty remains about whether to use absolute or relative change and how it relates to subject demographics.We studied absolute and relative forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) change in a population-based geriatric sample using a repeated measurements model adjusted for age, sex, smoking habits, heart failure, hypertension, diabetes, coronary heart disease, educational level, occupation, alcohol consumption, C-reactive protein (CRP) and body mass index. 3736 participants aged 60–102 years completed between one and five spirometries during 13.5 years of follow-up. Lung volumes, FEV1 quotient (Q) and Global Lung Initiative (GLI)-2012 and National Health and Nutrition Examination Survey (NHANES) III z-scores were presented from 6932 spirometries.Adjusted absolute change per year (95% CI) was −51.7 (−63.7–−39.9) mL for FEV1 and −56.2 (−73.6–−38.8) mL for FVC. Adjusted relative change per year was −2.97 (−3.53–−2.40)% for FEV1 and −2.46 (−3.07–−1.85)% for FVC. Risk factors for increased relative FVC and FEV1 decline were female sex, higher age, current smoking habits, elevated CRP (nonsignificant for FEV1, p=0.057) and low educational level. For increased absolute decline the risk factors were male sex and being a current smoker for FEV1 and low education for FVC.Relative but not absolute change correlated significantly with clinically relevant markers of functional status and may be superior to absolute change in risk factor analysis. Cross-sectional reduction in terms of FEV1Q was ∼1 unit per 10 years for both sexes. Proportions of subjects with results below lower limit of normal using NHANES III were close to anticipated, but were two to four times higher than expected using GLI-2012.

Rate of normal lung function decline in ageing adults: a systematic review of prospective cohort studies

“…In Triebner et al ,32 obese individuals reported greater declines of FEV 1 (29 mL/year) and FVC (25 mL/year) compared with individuals with normal BMI (FEV 1 22 mL/year, FVC 10 mL/year). In Luoto et al ,35 having a BMI greater than 35 was significantly associated with a slower decline of FEV 1 (32 mL/year compared with 46 mL/year, p=0.04), but it did not significantly affect FVC decline.…”

<p>Fixed Ratio versus Lower Limit of Normality for Diagnosing COPD in Primary Care: Long-Term Follow-Up of EGARPOC Study</p>

“…However, these studies were carried out in the general population; only 50% had a smoking history, and the presence of respiratory symptoms was not specified. 8,29 In contrast, in our study, performed carried out in a population of similar age, all patients had a smoking history, and 97% were symptomatic at inclusion. We believe that in these patients the obstruction measured with FR strongly suggests the presence of disease.…”

<p>Characteristics Associated with Accelerated Lung Function Decline in a Primary Care Population with Chronic Obstructive Pulmonary Disease</p>

“…This is consistent with previous studies that found no association between smoking status and rate of FVC decline in the general population and in COPD populations. 19,38,39 ICS Interestingly, we found that patients on ICS-containing medications were more likely to have accelerated FEV 1 decline. Many RCTs have investigated the relationship between ICS and lung function in COPD and results have shown that patients on ICS have attenuated rate of FEV 1 decline compared to non-ICS treatments.…”

“…17,18 FVC has been described longitudinally in populations without COPD but the rate of FVC decline in COPD patients is poorly described. [19][20][21][22] The rate of lung function decline in a generalizable population of average, "real world" COPD patients who would be seen in primary care has not been described. In addition, few studies have looked at how comorbidities, as well as other clinical characteristics such as medication, symptoms, and patient demographics, influence the rate of lung function decline, as measured by both FEV 1 and FVC in COPD patients in primary care.…”