|Year : 2021 | Volume
| Issue : 2 | Page : 103-107
A comparative study of platelet indices in stable versus acute exacerbation of chronic obstructive pulmonary disease
R Archita, ML Ashok
Department of Medicine, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
|Date of Submission||04-Nov-2020|
|Date of Decision||14-Dec-2020|
|Date of Acceptance||30-Dec-2020|
|Date of Web Publication||21-Apr-2021|
Dr. R Archita
No. 30 A, New No. 1045, 19th C Main, 1st Block, Rajaji Nagar, Bengaluru - 560 010, Karnataka
Source of Support: None, Conflict of Interest: None
Background and Objectives: Chronic obstructive pulmonary disease (COPD) is a major global health problem. A strategy for prevention and early treatment of COPD exacerbations is essential to better address the disease. Hence, the study was undertaken to compare the various platelet indices in patients with acute exacerbation versus stable COPD and study the relationship of these indices with the severity of COPD exacerbation to aid in better patient management. Methodology: The study was conducted at the hospitals attached to Bangalore Medical College and Research Institute from November 2017 to May 2019, on patients with stable and acute exacerbation of COPD. Brief history with relevant investigations was performed. Platelet indices were compared between the two groups. The relationship between the platelet indices and the severity of acute exacerbation of COPD was also studied. Results: Among the platelet indices, there was a statistical difference in the mean values of mean platelet volume (MPV) and platelet distribution width (PDW) in the two groups. The MPV and PDW values were 8.85 fL and 7.91 fL and 15.94% and 17.14%, respectively, during the stable period and exacerbations of COPD, respectively. Furthermore, in our study, it was found that there was no significant association between the degree of hypoxia and the platelet indices. Conclusion: Among the various platelet indices, our study suggests that the MPV reduced and PDW increased in patients with acute exacerbation when compared to stable COPD. Furthermore, our study did not show any significant correlation between the platelet indices and the severity of COPD as determined by the degree of hypoxia.
Keywords: Chronic obstructive pulmonary disease, hypoxia, mean platelet volume, platelet distribution width, platelet indices, plateletcrit
|How to cite this article:|
Archita R, Ashok M L. A comparative study of platelet indices in stable versus acute exacerbation of chronic obstructive pulmonary disease. APIK J Int Med 2021;9:103-7
|How to cite this URL:|
Archita R, Ashok M L. A comparative study of platelet indices in stable versus acute exacerbation of chronic obstructive pulmonary disease. APIK J Int Med [serial online] 2021 [cited 2021 Jun 12];9:103-7. Available from: https://www.ajim.in/text.asp?2021/9/2/103/314205
| Introduction|| |
Chronic obstructive pulmonary disease (COPD) represents an important public health challenge and is a major cause of morbidity and mortality. It is currently the fourth leading cause of death in the world. The Global Initiative for COPD (GOLD) was implemented to increase awareness and improve management of COPD. Because of the difficulties in objectively assessing symptom changes during exacerbations, there has been great interest in the development of biomarkers indicating the same. However, many of these are invasive, complex, and difficult to analyze.
Attention has consequently turned to systemic markers, and it is now widely accepted that COPD is associated with increased systemic inflammation. The association of platelet indices with COPD exacerbation has not been adequately evaluated, and there have been only limited studies evaluating this issue with controversial results.
Platelet indices and chronic obstructive pulmonary disease
Recent studies have shown that COPD is associated with a low-grade systemic inflammation associated with oxidative stress, activation of circulating inflammatory cells, and increased inflammatory cytokines. On activation, platelets release various chemokines from their α-granules such as MIF, CXCL4, CXCL7, or CXCL5. CXCL5 is a chemokine of potential importance in the regulation of lung inflammation, by modulating neutrophil transepithelial and transendothelial migration and accumulation in the alveoli. Platelets also influence MMPs' activity which contributes to the pathophysiology of COPD.
Mechanisms through which platelet activation may occur in patients with COPD include hypoxia, tachycardia, and hyperglycemia. Activation of platelets causes morphological changes such as pseudopodia formation which enhances adhesion and cohesion. Platelets with pseudopodia have heterogeneous size and increased platelet distribution width (PDW). Plateletcrit (PCT) provides information regarding the total platelet mass, which is linked with hypercoagulability.
During episodes of exacerbation of the disease, the inflammatory state worsens and leads to overproduction of various proinflammatory cytokines and acute phase reactants such as interleukin 6, C reactive protein (CRP) and fibrinogen. These pro-inflammatory cytokines can suppress the size of platelets by interfering with megakaryopoiesis with a subsequent release of small sized platelets from the bone marrow, leading to reduced Mean Platelet Volume (MPV) during acute exacerbations.
- To compare the platelet indices in patients with acute exacerbation versus stable COPD
- To study the relationship between platelet indices and the severity of COPD exacerbation.
| Methodology|| |
After obtaining institutional ethical committee clearance and written informed consent, patients with COPD presenting to the hospitals affiliated to Bangalore Medical College and Research Institute from November 2017 to May 2019 were taken for the study. Fifty-one patients diagnosed with acute exacerbation and 51 patients who presented in the stable phase were included.
An acute exacerbation of COPD was defined according to the GOLD guidelines – patients previously diagnosed with COPD who present with:
- Sustained increase in breathlessness (dyspnea) or
- Increased cough or sputum production or
- Sputum color change.
An acute exacerbation of COPD was defined according to the GOLD guidelines as patients previously diagnosed with COPD who present with sustained increase in breathlessness (dyspnea), increased cough / sputum production or sputum color change, which is acute in onset, beyond the normal day to day variations and leads to an increase in the use of maintenance medications and/or supplementation with additional medications. Stable COPD included those patients who were maintaining well on regular medications with no new complaints presenting to the hospital for regular follow-up.
Patients <18 years, those not willing to give consent, and patients with pneumonia, bronchial asthma, coronary artery disease, active pulmonary TB, cardiac failure, chronic liver/kidney disease, type 2 diabetes mellitus, pulmonary thromboembolism, inflammatory bowel disease, cystic fibrosis, connective tissue disease, malignancies, use of antiplatelet medications or anticoagulants in the past 15 days, or use of systemic steroids in the past 30 days were excluded.
Patient information was collected, detailed history was taken, and clinical examination was done. Investigations including complete blood count with platelet indices, erythrocyte sedimentation rate (ESR), sputum Gram stain and culture sensitivity, arterial blood gas (ABG), spirometry (for stable patients), and others as relevant were performed. Platelet indices were compared between the two groups. The relationship between the platelet indices and the severity of acute exacerbation of COPD was also studied (severity of exacerbation of COPD was indicated by the degree of hypoxemia). Further sampling or follow-up was not done.
IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp was used to perform the statistical analysis.
- Data were entered in the excel spread sheet
- Descriptive statistics of the explanatory and outcome variables were calculated by mean and standard deviation for quantitative variables and frequency and proportions for qualitative variables
- Inferential statistics such as
- Independent sample t-test was applied to compare the quantitative variables (mean platelet volume [MPV], PCT, PDW, and ESR) between the groups (acute exacerbation and stable)
- Pearson's correlation was applied to correlate ABG pO2 with MPV, PCT, and PDW
- The level of significance is set at 5%.
| Results|| |
Out of a total of 102 patients in this study, 51 patients with stable COPD and 51 patients presenting with acute exacerbation were included. The mean age of the patients in the stable group was 68.2 years, whereas the mean age among the patients with acute exacerbation was 49.98 years [Table 1]. The study comprised 14 females (13.7%) and 88 males (86.27%) [Figure 1]. Among the patients with stable COPD, there were 9 females (17.6%) and 42 males (82.3%). Among the patients with acute exacerbation, there were 5 females (9.8%) and 46 males (90.1%).
Comparison of the platelet indices in patients with acute exacerbation versus stable chronic obstructive pulmonary disease
The mean value of MPV was 7.91 fL in the acute exacerbation group when compared to 8.85 fL in the stable group. There was a significant decrease in the average MPV in the acute exacerbation group when compared to patients with stable COPD, with a significant P < 0.001 [Table 2]. There was no significant difference in the mean PCT values between the two groups, with a P = 0.39 [Table 3]; the mean value in patients with acute exacerbation of COPD was 0.22% when compared to 0.25% in patients with stable COPD.
|Table 2: Comparison of the mean platelet volume and platelet distribution width scores between the groups using independent sample t-test|
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The mean value of PDW was 17.14% in the acute exacerbation group when compared to 15.94% in the stable group, which was statistically significant.
Our study also showed an increase the values of ESR, a maker of inflammation in patients with acute exacerbation of COPD when compared to the stable group; however, the values were not statistically significant. The mean ESR value among patients with acute exacerbation was 14.94 mm/h and among those in the stable group was 12.80 mm/h, with a P = 0.40.
The mean pO2 value of the patients with acute exacerbation of COPD was 60.79 mm of Hg. In our study, the patients with acute exacerbation of COPD were further subdivided into categories 1–4 depending on the degree of hypoxia. Category 1 included patients with an ABG pO2 between 80 and 100 mm of Hg, category 2 60–80 mm of Hg, category 3 40–60 mm of Hg, and category 4 <40 mm of Hg. The distribution of the patients according to the pO2 values was 5, 19, 23, and 4 in each of the four groups, respectively.
Correlation between the platelet indices and severity of chronic obstructive pulmonary disease
Pearson's correlation between the degree of hypoxia to indicate the severity of COPD exacerbation and the mean values of platelet indices showed no significant association between the parameters [Table 4].
| Discussion|| |
This study was conducted to compare the platelet indices among patients with stable and acute exacerbation of COPD and also to study the correlation between the platelet indices and the severity of acute exacerbation, as indicated by the degree of hypoxemia on ABG analysis.
In our study, among the 51 patients with stable COPD and 51 patients with acute exacerbation, the mean age among patients in the stable phase was 68.2 years and in those presenting with acute exacerbation was 49.98 years. In a study done by Kalemci et al., on a total of 153 patients admitted with COPD at Turkey, the mean age of the patients depending on the severity of COPD was as follows: mild – 57.1 years, mild-to-moderate – 58.7 years, moderate-to-severe – 65.4 years, and severe – 73.8 years. In a study done by Ragulan et al. on 135 subjects with COPD in Tamil Nadu, 79 were males and 56 were females.
The various available data suggest that older patients with COPD have more severe disease and symptoms and increased comorbidities and mortality. Contrary to other studies, our study showed a lower mean age of patients in the exacerbation group when compared to the stable group. The plausible reason might be because of the fewer number of elderly patients seen approaching the hospital for exacerbations and seeking treatment for the same and the need to exclude many of the elderly patients from our study due to the presence of the existing comorbid conditions / drug intake that could impact the platelet indices.
Comparison of platelet indices among patients with stable and acute exacerbation of chronic obstructive pulmonary disease
MPV – According to previous studies, there is a significant decrease in the MPV during exacerbation of COPD when compared to stable controls, suggesting that MPV can be used as an inflammatory marker in COPD exacerbation. A study done by Ragulan et al. on 135 subjects in Tamil Nadu showed a decrease in the MPV in the study group (8.573 fL) when compared to the control group (9.1 fL). According to Wang et al., MPV is significantly reduced during exacerbation when compared to controls, and they also found an increase in CRP, fibrinogen, and WBC levels in patients with exacerbation of COPD. Our study also showed similar results Contrary to our study, Bansal et al. revealed that the MPV was increased in COPD patients when compared to controls and also suggested that COPD patients with increased MPV were predisposed to pulmonary thromboembolism and pulmonary hypertension. PCT – Previous studies have not shown any consistent or significant difference in the PCT among patients with exacerbation of COPD when compared to control groups, similar to our results. A study done by Ragulan et al. on 135 subjects in Tamil Nadu showed an increase in the PCT in the study group (0.148%) when compared to the control group (0.097%). Makhlouf et al. showed that PCT is higher in diabetic or nondiabetic patients with COPD compared with healthy controls. PDW – Previous studies have shown an increase in the PDW as the severity of COPD increased, as a result of an increase in the thrombosis load and/or increased inflammation that occurs as the disease becomes more severe. Ragulan et al. showed that the PDW was higher in patients in the study group (17.319) when compared to patients in the study group (15.961). In a study by Kalemci et al., PDW and red cell distribution width were independently associated with the presence of severe COPD, irrespective of the effect of age. Furthermore, PDW was shown to increase in various other pulmonary diseases other than COPD. Consistent with the previous studies, in our study also, the PDW was significantly increased in the acute exacerbation group when compared to the stable group with a P < 0.001. Similar to other studies, our study also showed an increase in other parameters of inflammation, like ESR in patients with acute exacerbation of COPD when compared to the stable group; however, the values were not statistically significant. A study by Mohan et al. showed significantly elevated mean levels of ESR, CRP, total leukocyte count, neutrophils, ferritin, and fibrinogen in COPD patients compared to controls.
Correlation between the platelet indices and severity of chronic obstructive pulmonary disease
Correlation between the platelet indices and the severity of chronic obstructive pulmonary disease indicated by the degree of hypoxia
To the best of our knowledge, there have been no studies in English literature investigating the relationship between platelet indices and the severity of COPD based on the degree of hypoxia. Our study aimed to study the correlation between the platelet indices and the severity of COPD based on the degree of hypoxia. However, there was no significant correlation between the severity of hypoxia and the platelet indices.
| Conclusion|| |
Platelet indices have been used as simple and promising markers in several inflammatory circumstances. Our study suggests that the MPV is reduced and PDW increased in patients with acute exacerbation when compared to stable COPD. However, our study did not show any significant correlation between the platelet indices and the severity of COPD as determined by the degree of hypoxia. These differences in the platelet indices between the two groups could indicate the underlying degree of hypoxemia, inflammation, and oxidative stress in patients with COPD.
Furthermore, large-scale studies are required to evaluate the effectiveness of the various platelet indices as relatively simple, inexpensive, and noninvasive tests in identifying patients with acute exacerbation of COPD, thereby facilitating timely management.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]