Anemia of Chronic Disease in Chronic Obstructive Pulmonary Disease: A Case-Control Study of Cardiopulmonary Exercise Responses

Abstract

Background: Anemia may be present in patients with chronic obstructive pulmonary disease (COPD) and further impair their functional capacity. Objectives: This study investigated the prevalence of anemia of chronic disease (ACD) in COPD patients and its impact on dyspnea and exercise capacity, utilizing cardiopulmonary exercise testing (CPET). Methods: ACD prevalence was assessed in 283 consecutive patients with stable COPD (263 males, 60 females; age 60.31 ± 5.34 years; percent forced expiratory volume in 1 s 46.94 ± 6.12). ACD diagnosis was based on a combination of clinical and laboratory parameters [hemoglobin (Hb) <13 g/dl for males, <12 g/dl for females; ferritin >30 ng/ml; total iron-binding capacity <250 µg/dl, and transferrin saturation rate between 15 and 50%]. Twenty-seven patients who were identified with ACD (cases) and 27 matched nonanemic patients (controls) completed maximal CPET, and data were compared between the groups. Results: ACD was diagnosed in 29 patients, which represents a prevalence of 10.24%; the severity of anemia was generally mild (mean Hb: 12.19 ± 0.66 g/dl). Patients with ACD had a higher Medical Research Council dyspnea score compared to controls (2.78 ± 0.44 vs. 2.07 ± 0.55; p <0.001) and lower peak O₂ uptake (VO₂) (59.54 ± 17.17 vs. 71.26 ± 11.85% predicted; p <0.05), peak work rate (54.94 ± 21.42 vs. 68.72 ± 20.81% predicted; p <0.05) and peak VO₂/heart rate (69.07 ± 17.26 vs. 82.04 ± 18.22% predicted; p <0.05). There was also a trend for a lower anaerobic threshold (48.48 ± 15.16 vs. 55.42 ± 9.99% predicted; p = 0.062). No exercise parameter indicative of respiratory limitation differed between the groups. Conclusions: ACD occurs in approximately 10% of stable COPD patients and has a negative impact on dyspnea and circulatory efficiency during exercise.

Non‐anaemic iron deficiency impairs response to pulmonary rehabilitation in COPD

“…One report 10 studied iron status in a marginal number of nonanaemic COPD patients, and two additional studies only studied iron deficiency in COPD patients with anaemia. 11,12 Moreover, to our knowledge, no previous studies have addressed the effects of endurance training in chronic patients suffering from NAID.…”

“…[7][8][9] In contrast, in patients with chronic obstructive pulmonary disease (COPD), iron deficiency has only been studied in the context of anaemia. [10][11][12] Patients with COPD often show oxygen delivery impairment during exercise. Moreover, skeletal muscle dysfunction is a well recognized systemic effect of the disease that can be associated to abnormal mitochondrial oxygen utilization.…”

Chronic obstructive pulmonary disease: consequences beyond the lung

“…31 Anaemia of chronic disease occurs in about 10% of patients with COPD and is associated with worse quality of life and impaired survival. 32 …”

Anemia as a comorbidity in chronic obstructive pulmonary disease - A hospital-based study in East Sikkim

“…This was mild anemia which is similar to the previous studies. [6,18,19] In our present study, anemia defined by Hct <39% in males and <36% in females. We found that anemia was present in 25.6% of males and 34.2% of females which is higher than the findings of Chambellan et al where they reported that 13% of males and 8% females were anemic.…”

“…The trend was not the same in female patients. Maximum female patients were anemic (Hb <12) in 71-80 age group (23, 11.1%) followed by 61-70 years (19,9.2%) as shown in Table 2.…”