Chronic Respiratory Diseases Linked to Other Noncommunicable Diseases in Vulnerable Countries

Despite their devastating global impact, chronic respiratory diseases remain a hidden threat in low- and middle-income countries, often going undiagnosed in adults who are already battling other noncommunicable diseases. | Image Credit: Tipapat - stock.adobe.com

Chronic respiratory diseases (CRDs) are present in adults with other noncommunicable diseases (NCDs) in low- and middle-income countries (LMICs), but the overall prevalence varies depending on the specific NCD studied, according to a study published in BMC Pulmonary Medicine.¹

Asthma, chronic obstructive pulmonary disease (COPD), and occupational lung diseases are among some of the most common CRDs.² Around 2 billion people are exposed to toxic biomass fuels, while another 1 billion are impacted by outdoor air pollution. An additional 1 billion smokers expose a similar number of people to harmful secondhand smoke, contributing to the roughly 4 million premature deaths from CRDs each year.

Oftentimes, CRDs occur in combination with other NCDs because of shared factors like socioeconomic disadvantage, noxious respiratory exposures, and aging.¹ It is predicted that the most prevalent NCD will lead to global economic losses totaling $47 trillion by 2030.

“This review aims to identify the prevalence of CRD and/or abnormal spirometry results identified through case-finding tools in adults with NCD living in LMIC,” study authors stated.

After an initial screening of 8939 studies, researchers narrowed their focus to 13 for a more detailed review. Of those, 9 were ultimately excluded for various reasons, including 5 that lacked sufficient data, 2 that had inadequate outcome measurements, 2 that were conducted in developing countries, and 1 that included patients who had already been diagnosed with COPD.

Only 3 studies met the inclusion criteria, with 1 from India and 2 from Brazil. There were 2 of these studies that used convenience sampling, including 255 people, while the third recruited 1162 participants from the general population at Basic Health Units. Spirometry was the primary diagnostic tool in 2 studies, while the third used a combination of case-finding tools.

Researchers in the review analyzed a study of 1162 adults with hypertension in Brazil and found that 12 also had undiagnosed asthma (95% CI, 0.59-1.9), 19 had asthma-COPD overlap (95% CI, 1.0-2.5), and 60 had undiagnosed COPD (95% CI, 4.0-6.6). The average age of the participants was 62.3 years, and about a third were men (32.5%).

In a study from the review, researchers performed spirometry on 50 patients with end-stage kidney disease at a tertiary hospital. The average age of the participants was 45.8 years, and 64% were men. The results showed that 41 people had restrictive spirometry (95% CI, 69.2-90.2), and 3 had obstructive or mixed spirometry (95% CI, 2.0-16.2).

In a separate study of 205 patients being evaluated for coronary artery disease, 23 met the criteria for COPD (95% CI, 7.5-16.2), and 35 showed impaired spirometry (95% CI, 12.5-22.8) with a preserved ratio. The majority of participants were men (55%), but the average age was not reported.

The high prevalence of NCDs in LMICs places a heavy burden on already struggling economies, often pushing families and communities into poverty.³ Preventing these diseases requires a comprehensive approach, including policies that acknowledge their devastating societal effects. Public health experts must build alliances with diverse sectors and work with policymakers to ensure these policies are implemented. Still, proposing large-scale policy changes remains difficult without carefully considering their potential impact on affected populations and the specific policy environment.

The review has several limitations, starting with its small sample size.¹ The researchers were only able to include 3 studies, all from a limited geographical area, which restricts the findings from being generalized to other LMICs. Additionally, the original articles did not include 95% confidence intervals for prevalence estimates, so these had to be calculated from the provided data. The review also excluded unpublished "grey literature" and studies that were not available in full text. Finally, the use of artificial intelligence models was an unexpected part of the study's process and was not included in the initial registration.

“Future research should aim to expand geographical coverage and methodological quality, while further exploring the interplay between NCDs and CRDs to inform targeted screening and early intervention strategies in LMIC,” study authors concluded.

References

1. Petrolini-Mateus A, Araujo GHG, Schafauser-Segundo NS, et al. Prevalence of chronic respiratory disease using case-finding tools in adults living with noncommunicable disease in low- and middle-income countries: a systematic review. BMC Pulm Med. 2025;25(1). doi:10.1186/s12890-025-03697-8
2. Soriano JB, Kendrick PJ, Paulson KR, et al. Prevalence and attributable health burden of chronic respiratory diseases, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet Respir Med. 2020;8(6):585-596. doi:10.1016/S2213-2600(20)30105-3
3. Ndubuisi NE. Noncommunicable diseases prevention in low- and middle-income countries: an overview of health in all policies (HiAP). Inquiry. 2021;58:46958020927885. doi:10.1177/0046958020927885