The study for asthma in older adults: a combined analysis of the effects of occupational asthmagens, high body-mass index and smoking

Abstract

Background: Asthma remains a significant public health challenge globally, particularly among older adults who face diagnostic complexity, atypical symptom profiles, and frequent comorbidities. Despite global advances in asthma control, little attention has been paid to the evolving composition and geographic disparity of modifiable risk factors in this age group.

Methods: We utilized data from the Global Burden of Disease Study 2021 to evaluate the long-term trends (1990-2021) in asthma burden attributable to high body-mass index (BMI), smoking, and occupational asthmagens among adults aged 60 years and older. Key metrics included age-standardized mortality rates (ASMR), age-standardized DALY rates (ASDR), and estimated annual percentage change (EAPC). Stratified analyses were conducted across Socio-demographic Index (SDI) quintiles, gender, and detailed 5-year age subgroups (60-64 to ≥95 years) to assess disparities across socioeconomic development, gender, and aging patterns, with additional stratification by geographic region.

Results: From 1990 to 2021, asthma burden attributable to smoking and occupational asthmagens among older adults declined globally, while high BMI-related burden increased in several middle and low SDI regions. In terms of attribution proportion, the proportion of asthma deaths attributable to high BMI increased from 10.89 to 14.4%, with this upward trend being particularly pronounced in high SDI regions. Occupational asthmagens-related burden showed limited decline and remained elevated in low SDI regions. Gender-stratified analysis showed that the risk burden of smoking was higher in older men in Asia, whereas the high BMI-related burden was higher in women in more developed regions.

Conclusion: This study demonstrates a structural shift in the composition of asthma risk factors among older adults, with high BMI emerging as a dominant contributor amid declining traditional behavioral risks such as smoking. There are significant differences among regions, age groups and genders. Targeted, region-specific strategies are essential to address these evolving risks and reduce inequities in asthma burden among aging populations.

Keywords: asthma burden; high body-mass index; occupational asthmagens; older adults; smoking.

Figure 1

ASMR and DALY rate of asthma attributable to risk factors from 1990 to 2021, categorized by global and SDI regions. (A) ASMR due to high BMI. (B) ASDR due to high BMI. (C) ASMR due to smoking. (D) ASDR due to smoking. (E) ASMR due to occupational asthmagens. (F) ASDR due to occupational asthmagens.

Figure 2

ASDR (per 100,000 population) of asthma attributable to risk factors from 1990 to 2021, across 21 GBD regions. The figure illustrates the contributions of high BMI (blue line), smoking (orange line), and occupational asthmagens (green line) to asthma ASDR.

Figure 3

Global spatial distribution of ASMR and EAPC of asthma attributable to risk factors in 2021. (A) ASMR due to high BMI. (B) EAPC of ASMR due to high BMI. (C) ASMR due to smoking. (D) EAPC of ASMR due to smoking. (E) ASMR due to occupational asthmagens. (F) EAPC of ASMR due to occupational asthmagens.

Figure 4

Global spatial distribution of ASDR and EAPC of asthma attributable to risk factors in 2021. (A) ASDR due to high BMI. (B) EAPC of ASDR due to high BMI. (C) ASDR due to smoking. (D) EAPC of ASDR due to smoking. (E) ASDR due to occupational asthmagens. (F) EAPC of ASDR due to occupational asthmagens.

Figure 5

Age-specific DALYs rates (per 100,000 population) of asthma attributable to high BMI in 1990 versus 2021, across 21 GBD regions and various age groups. The figure illustrates the changes in DALY rates for each region across different age groups (1990 in green, 2021 in blue).

Figure 6

Age-specific DALYs rates (per 100,000 population) of asthma attributable to smoking in 1990 versus 2021, across 21 GBD regions and various age groups. The figure illustrates the changes in DALY rates for each region across different age groups (1990 in green, 2021 in blue).

Figure 7

Age-specific DALYs rates (per 100,000 population) of asthma attributable to occupational asthmagens in 1990 versus 2021, across 21 GBD regions and various age groups. The figure illustrates the changes in DALY rates for each region across different age groups (1990 in green, 2021 in blue).

Figure 8

Age-specific sex ratio (male vs. female) of mortality and DALYs rates for asthma attributable to risk factors in 2021, across global, five SDI regions, and 21 GBD regions. (A) Age-specific sex ratio of mortality attributable to high BMI. (B) Age-specific sex ratio of mortality attributable to smoking. (C) Age-specific sex ratio of mortality attributable to occupational asthmagens. (D) Age-specific sex ratio of DALYs attributable to high BMI. (E) Age-specific sex ratio of DALYs attributable to smoking. (F) Age-specific sex ratio of DALYs attributable to occupational asthmagens.

Figure 9

Correlation analysis between ASMR and ASDR of asthma attributable to risk factors and SDI from 1990 to 2021, across 21 GBD regions. The figure displays the correlation coefficient (R) and p-value. (A) Correlation between ASMR due to high BMI and SDI. (B) Correlation between ASMR due to smoking and SDI. (C) Correlation between ASMR due to occupational asthmagens and SDI. (D) Correlation between ASDR due to high BMI and SDI. (E) Correlation between ASDR due to smoking and SDI. (F) Correlation between ASDR due to occupational asthmagens and SDI.

Figure 10

Proportion of asthma mortality and DALYs rates attributable to risk factors in 1990 and 2021, across global, five SDI regions, and 21 GBD regions. (A) Proportion of asthma mortality attributable to high BMI, smoking, and occupational asthmagens in 1990 and 2021. (B) Proportion of asthma DALYs rates attributable to high BMI, smoking, and occupational asthmagens in 1990 and 2021.