Illness Perception, Function Interact After COPD and Diabetes Discharge

Older adults with comorbid chronic obstructive pulmonary disease (CODP) and type 2 diabetes (T2D) face a particularly vulnerable period during the transition from hospital to home, according to a prospective cohort study published in Frontiers in Medicine.¹

Researchers found that patients' illness perception and intrinsic capacity—a World Health Organization (WHO) framework describing an individual's overall functional reserve across cognitive, psychological, vitality, sensory, and locomotor domains—interact dynamically over the 3 months following discharge, with implications for how clinicians structure transitional care.¹

The study, conducted from April 2024 to September 2025 at The Sixth People's Hospital of Nantong in China, enrolled 232 patients 60 years and older who had been hospitalized for an acute exacerbation of COPD or poor glycemic control and were being discharged home. Patients were assessed at discharge, 1 month post-discharge, and 3 months post-discharge using the Brief Illness Perception Questionnaire (BIPQ) and a WHO framework-based intrinsic capacity assessment tool.¹

Bidirectional Relationship Shifts Over Time

Using a random-intercept cross-lagged panel model, investigators found that during the early transition phase—from discharge to 1 month—illness perception and intrinsic capacity were significantly and bidirectionally linked. Patients with more negative illness perception at discharge had poorer intrinsic capacity 1 month later (β = -0.21; P = .003), and patients with poorer intrinsic capacity at discharge reported more negative illness perception 1 month later (β = 0.18; P = .012).¹

That pattern changed between month 1 and month 3. The predictive effect of illness perception on intrinsic capacity was no longer significant (β = -0.11; P = .105), but poorer intrinsic capacity at 1 month remained significantly associated with more negative illness perception at 3 months (β = 0.15; P = .047). The authors noted that this suggests intrinsic capacity's influence on illness perception is more sustained across the transition period, while illness perception's effect on intrinsic capacity is strongest early on.¹

Across the study period, illness perception scores improved—the mean BIPQ score fell from 45.2 at discharge to 40.5 at 3 months (P < .001)—while intrinsic capacity scores showed a slight but statistically significant decline, driven primarily by increases in locomotor impairment (48.3% to 61.2%) and vitality impairment (31.9% to 40.5%). A parallel process latent growth model found that patients whose illness perception improved faster also experienced a slower rate of decline in intrinsic capacity (r = 0.32; P = .008), reinforcing that the two trajectories are linked at the level of overall change, not just at individual time points.¹

Exploratory subgroup analyses identified COPD severity and baseline vitality status as clinically meaningful moderators. Among patients with severe COPD (GOLD stage 3-4), the negative predictive effect of illness perception on intrinsic capacity was significant (β = -0.28; P = .001), while it was not significant among patients with mild-to-moderate disease (GOLD stage 2) (β = -0.12; P = .215).¹

Similarly, among patients with impaired baseline vitality (Mini Nutritional Assessment-Short Form score ≤ 11), the negative effect of illness perception on intrinsic capacity was stronger (β = -0.32; P = .002) compared with patients with normal vitality status. The authors cautioned that although these between-group differences reached statistical significance at the raw level, they did not consistently survive Bonferroni correction, so the moderating effects should be considered exploratory pending validation in larger samples.¹

Relevance for Pharmacists and the Broader Comorbidity Burden

The interaction between COPD and diabetes is well documented beyond this cohort study. A retrospective analysis of more than 7.4 million COPD hospitalizations found that diabetes with complications was associated with increased odds of extended length of stay (odds ratio [OR], 1.40), pneumonia (OR, 1.04), respiratory failure (OR, 1.05), and acute kidney injury (OR, 1.594) compared with COPD hospitalizations without diabetes.²

A separate narrative review noted that up to 30% of COPD patients have comorbid T2D and that systemic inflammation—driven by cytokines such as tumor necrosis factor-alpha, interleukin-6, and C-reactive protein—forms a shared pathophysiological pathway linking the two conditions.³

According to a patient-facing fact sheet from the Respiratory Health Association, as many as 37% of patients with COPD may also have diabetes, and hyperglycemia is believed to trigger an inflammatory response that reduces lung function.⁴

For pharmacists managing this comorbid population, the Nantong cohort study's findings point to the value of screening for both psychological adaptation and functional decline during medication reconciliation and discharge counseling, particularly in the first month after hospitalization when the bidirectional relationship between illness perception and intrinsic capacity is strongest.¹

The study authors suggested that transitional care strategies integrating illness perception therapy—such as providing clear disease information and helping patients reframe symptom interpretation—alongside functional interventions like pulmonary rehabilitation, nutritional optimization, and correction of sensory impairments may help interrupt what they described as a potential "cognitive-functional decline" cycle.¹

Study Limitations

The authors acknowledged several limitations, including the single-center, convenience-sampling design, which may limit generalizability to other regions or care settings. Sensory function was assessed by self-report rather than objective testing, and the intrinsic capacity score's dichotomized domain structure (0 to 5 scale) may have reduced sensitivity to subtle functional changes. The authors also noted that the observational design cannot rule out unmeasured time-varying confounders, meaning the bidirectional associations identified should be interpreted as dynamic correlations rather than definitive causal relationships.¹

REFERENCES

1. Peng X, Cheng X, Shen H, Xiao Q. The interaction between illness perception and intrinsic capacity during hospital-to-home transition in older adults with COPD and diabetes: a prospective cohort study. Front Med (Lausanne). 2026;13:1896128. Published 2026 Jul 22. doi:10.3389/fmed.2026.1896128

2. Gunasekaran K, Murthi S, Elango K, et al. The Impact of Diabetes Mellitus in Patients with Chronic Obstructive Pulmonary Disease (COPD) Hospitalization. J Clin Med. 2021;10(2):235. Published 2021 Jan 11. doi:10.3390/jcm10020235

3. Anghel L, Ciubară A, Patraș D, Ciubară AB. Chronic Obstructive Pulmonary Disease and Type 2 Diabetes Mellitus: Complex Interactions and Clinical Implications. J Clin Med. 2025;14(6):1809. Published 2025 Mar 7. doi:10.3390/jcm14061809

4. Respiratory Health Association. COPD and diabetes: what you need to know. Fact sheet. Respiratory Health Association. Accessed August 7, 2026. resphealth.org