https://doi.org/10.15218/ejnm.2019.12 Erbil j. nurs. midwifery, Vol. 2, No. (2), Nov, 2019 Original Article Chronic Obstructive Pulmonary Disease as a Cardiovascular Diseases Risk Factor in Erbil ABSTRACT INTRODUCTION Chronic obstructive pulmonary disease (COPD), which includes emphysema, asth- ma and chronic bronchitis, has been recog- nized as the most common cause of mor- bidity and mortality worldwide [1]. It is characterized by an obstruction of the lung airflow and not fully reversible due to long-term inflammatory process through- out the airways, parenchyma, and pulmo- nary vasculature [2]. Approximately 20% of adult populations have reduced Forced Expiratory Volume in the first second (FEV1) values, which indi- cate impaired lung function [3]. Asthma, COPD, and fibrotic lung disease have been Background and objectives: Chronic obstructive pulmonary disease (COPD) has been re- ported as the most common cause of morbidity and mortality all over the world. The pre- sent study aimed to investigate a possible link between chronic obstructive pulmonary dis- ease and increased risk of cardiovascular disease in Erbil, the Kurdistan Region of Iraq. Methods: A quantitative, case-control study was conducted on 159 patients with COPD as the case croup and 159 adult people without COPD as control group. Case groups were patients who have COPD and admitted to the medical ward at Hawler Teaching Hospital and Rzgary Teaching Hospital. Control groups were those without COPD and went to City Park and Mala-fandy Primary Health Center. Data was collected from January 2018 to Au- gust 2018 through direct interview and using a questionnaire. A spirometer machine was used to confirm the diagnosis of COPD. Data analysis was carried out through descriptive statistics (frequency and percentage), skeunosis-kurtosis test, t-test, Mann-Whitney U test, Pearson's Chi-squared test, and univariate logistic regression. Results: Compared to the control group, patients with chronic obstructive pulmonary dis- ease were found to be at a significantly higher risk of developing hypertension, diabetes, ischemic heart disease, dyslipidemia, and lung cancer. Moreover, there was an inverse cor- relation between increased severity of chronic obstructive pulmonary disease and in- creased hypertension and stroke. In addition, chronic obstructive pulmonary disease, hy- pertension, diabetes, and dyslipidemia were found to be significant risk factors for ischem- ic heart disease. Conclusions: The risk of cardiovascular comorbidities was significantly higher in the pa- tients with chronic obstructive pulmonary disease and there is a significant association be- tween chronic obstructive pulmonary disease and cardiovascular comorbidities. Keywords: Cardiovascular diseases, chronic obstructive pulmonary disease, Comorbidity Goran Aboobaker Osman; Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq. (Correspondence: goran.osman@hmu.edu.krd) Halmat Authman Rasheed; Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq. Yousif Mohammed Younis; Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq. Newroz Khazi Aziz; Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq. Hemin Khlid Saber; Department of Medicine, College of Medicine, Hawler Medical University, Erbil, Iraq. 93 Erbil Journal of Nursing & Midwifery Received: 4/4/2019 Accepted: 8/5/2019 Published: 30/5/2019 mailto:goran..osman@hmu.edu.krd https://doi.org/10.15218/ejnm.2019.12 Erbil j. nurs. midwifery, Vol. 2, No. (2), Nov, 2019 Original Article recognized in adult individuals whose level of FEV1 is reduced [4]. Low-grade systemic inflammation has also been associated with atherosclerosis, stroke and ischemic heart disease. These conditions are im- portant risk factors for cardiovascular mor- bidity and mortality among COPD patients [4]. Limited physical activity and cigarette smoke play a role in increased cardiovascu- lar disease [5]. Studies have found that many patients diagnosed with COPD even- tually die from cardiovascular disease; par- ticularly ischemic heart disease [6,7]. Ciga- rette smoking could be an independent risk factor as it is one of the most common shared risk factors in both COPD and cardi- ovascular disease patients [8]. High prevalence of diabetes, dyslipidemia and hypertension was observed in COPD patients which was related with an in- creased risk of ischemic heart disease [9]. The aim of this study was to determine whether or not COPD is associated with increased risk of cardiovascular disease compared to the control group. A quantitative case – control study was car- ried out from January 2017 to May 2019 to determine whether or not obstructive lung disease patients present greater cardiovas- cular diseases and comorbidity than con- trol subjects in the Erbil, Kurdistan region of Iraq. This study was approved by the Scientific and Ethical Committee at Hawler Medical University/ College of Nursing. Prior to data collection, all study participants were in- formed about the aim and characteristics of the study. They gave their written con- sent for participation. A questionnaire was constructed and Spi- rometer machine was used to collect the necessary data. Two experts in the field were present in order to approve and re- view the validity of the questionnaire. The questionnaire consisted of two sections. The first section was socio-demographical characteristics of patients. The second sec- tion was composed of questions regarding presence of cardiovascular disease, co- morbidities of obstructive lung disease, and severity of chronic obstructive pulmo- nary disease. A Spirometer is a tool used to confirm the diagnosis of COPD. Reduced Forced Expiratory Volume in the first sec- ond (FEV1), <80% of the predicted value in combination with an (Forced Expiratory Volume in the first second (FEV1) / Forced Vital Capacity (FVC) FEV1/FVC, <70% indi- cates the limitation of lung airflow that is not fully reversible [10,11]. Global Initiative on Obstructive Lung Disease criteria was used to categorize the severity of airflow limitation into stages: I: FEV1 ≥ 80%, II: FE- V1= 50–80, III: FEV1= 30–50, IV: FEV1<30 [1].The matching criteria for the case group as well as for the control group were: age over 40 years old and cigarette smoking history. The inclusion criteria for case groups were patients who have COPD and admitted to the medical ward at Hawl- er Teaching Hospital and Rizgary Teaching Hospital. Control groups were those with- out COPD and went to City Park for recrea- tion and Mala-fandy Primary Health Cen- ter. A total of 159 cases and 159 controls were selected purposively. During the time of data collection, only 159 patients were diagnosed with COPD. In order to have an equal number of cases and con- trols, 159 controls were selected to partici- pate in the study. All continuous variables were presented by mean and standard deviation. Frequency and percentage are used to express the result of the categorical variables. The skeunosis-kurtosis test was used to test the normality distribution of continuous variables. T-test was used to find the differences between groups in quantitative studies for those variables with normal METHODS 94 Erbil Journal of Nursing & Midwifery https://doi.org/10.15218/ejnm.2019.12 Erbil j. nurs. midwifery, Vol. 2, No. (2), Nov, 2019 Original Article found with case and control groups. With the exception of stroke (7.5% in case and 10.1% in control) and anemia (13.8% in case and 15.1% in control), the prevalence of all diseases was greater in COPD pa- tients than in controls. Ischemic heart dis- ease and hypertension were the greatest comorbidities in COPD group (82.4% and 71.7%) respectively. When the case group was classified by COPD severity using the Global Initiative on Obstructive Lung Disease criteria, it was found that hypertension (P = 0.111) and stroke significantly decreased as the sever- ity of the disease increased (and P < 0.001). There were no significant differ- ences between the stages of COPD for dia- betes and dyslipidemia. In stage IV of COPD, the prevalence of Ischemic heart disease was greater than in stage III (P= 0.256). However, there were no differ- ences between the other stages. In addi- tion, no significant differences were found between the stages for heart failure (Table 3). distribution and Mann–Whitney U test for non-normally distributed variables. Pearson’s Chi-squared test was used to an- alyze the association between qualitative variables. In order to find the relationship between cardiovascular disease and chron- ic obstructive pulmonary disease patients, the Univariate logistic regression was used. Results with P < 0.05 were considered sta- tistically significant. The demographic and respiratory function characteristics of the participants are shown in Table 1. Significant differences were found in the pulmonary function tests and there were no significant differences in terms of age. There were no differences between the groups in the distribution by sex, body mass index and cigarette smoking habits. Majority of patients were found to be in first and second stage of COPD. Table 2 shows the prevalence of cardiovas- cular disease and comorbidities that were 95 RESULTS Erbil Journal of Nursing & Midwifery Table 1: Demographical characteristics and respiratory function of the study participants Characteristics Case N(%) /M±SD Control N(%) /M±SD P value Sex Males 104(65.4) 104(65.4) > 0.999 Females 55(34.6) 55(34.6) Age (years) 62.05 ± 11.09 61.73 ± 11.47 0.800 BMI 26.23 ± 4.03 25.86 ± 3.17 0.354 Pack-years 1.086 ± 0.60 1.15 ± 0.67 0.398 FEV (%) 55.49 ± 18.06 80.01 ± 20.76 < 0.001 FVC (%) 47.70 ± 16.73 67.15 ± 16.89 < 0.001 FEV/FVC (%) 56.44 ± 10.37 74.86 ± 5.30 < 0.001 GOLD STAGES of COPD I 26(16.4) II 126(79.2) III 3(1.9) IIII 4(2.5) https://doi.org/10.15218/ejnm.2019.12 Erbil j. nurs. midwifery, Vol. 2, No. (2), Nov, 2019 Original Article The prevalence of ischemic heart disease was greater in the presence of diabetes mellitus (P = 0.005), hypertension (P < 0.001), and dyslipidemia (P < 0.001) as well as cigarette smoking (P < 0.001). However, there were no significant differences be- tween IHD and age group. Meanwhile, the prevalence of heart failure was also higher in the presence of dyslipidemia (P = 0.013). The Chi-squared analysis was used to find the association between cardiovascular and age groups. In this case, the Bonferroni correction showed that there is no signifi- cant difference in age group (Table 4). Table 5 demonstrated that chronic ob- structive pulmonary disease patients have greater risks for having hypertension (odds ratio [OR]: 7.77; 95% confidence interval [CI]: 4.71-12.82), diabetes mellitus (OR: 4.52; 95% CI: 2.77-7.37), and dyslipidemia (OR: 17.05; 95% CI: 9.72- 29.89). A univari- ate logistic regression analysis showed that COPD, hypertension, diabetes, and dyslipidemia were risk factors for ischemic heart disease. 96 Table 2: Prevalence of cardiovascular disease and comorbidities among study sample Erbil Journal of Nursing & Midwifery Table 3: Prevalence of cardiovascular disease and comorbidities in patients with chronic obstructive pulmonary disease classified by degrees of severity. CVD and Co-morbidities Case N (%) Control N (%) P -Value Ischemic heart disease 131(82.4) 14 (8.8) < 0.001 Heart failure Hypertension 21 (13.2) 114 (71.7) 5 (3.1) 39 (24.5) 0.001 < 0.001 Dyslipidemia Stroke Diabetes 124 (78) 12 (7.5) 89 (56) 34 (21.4) 16 (10.1) 28 (17.6) < 0.001 0.429 < 0.001 Anemia 22 (13.8) 24 (15.1) 0.750 Comorbidities I: FEV1 ≥ 80% II: FEV1= 50–80 III: FEV1= 30–50 IV: FEV1<30 P-Value Hypertension 22 (19.3%) 85 (74.6%) 3 (2.6%) 4 (3.5%) 0.111 Stroke 2 (16.7%) 8 (66.7%) 2 (16.7%) 0 (0%) 0.001 IDH 24 (18.3%) 100 (76.3%) 3 (2.3%) 4 (3.1%) 0.256 Heart failure 2 (9.5%) 18 (85.7%) 0(0%) 1 (4.8%) 0.624 Dyslipidemia 23 (18.5%) 96 (77.5%) 2 (1.6%) 3 (2.4%) 0.543 Diabetes 13 (14.6%) 71 (79.8%) 3 (3.4%) 2 (2.2%) 0.423 Anemia 2 (9.1%) 18 (81.8%) 1 (4.5%) 1 (4.5%) 0.528 https://doi.org/10.15218/ejnm.2019.12 Erbil j. nurs. midwifery, Vol. 2, No. (2), Nov, 2019 Original Article 97 Table 4: Prevalence of cardiovascular disease in patients with chronic obstructive pulmo- nary disease according to risk factors. Erbil Journal of Nursing & Midwifery Risk factors IHD N (%) HF N (%) Hypertension Yes No 107 (81.7%) 17(81%) 24 (18.3%) 4(19%) Diabetes Yes NO 80 (61.1%) 11(52.4%) 51 (38.9%) 10(47.6%) Dyslipidemia Yes NO 120 (91.6%) 12 (57.1%) 11 (8.4%) 9(42.9%) Anemia Yes NO 19 (14.5%) 5 (23.8%) 112(85.5%) 16(76.2%) Age group/year 40-51 52-63 64-75 76-87 31 (23.7%) 0 (0%) 39 (29.8%) 5 (23.8%) 43 (32.8%) 11 (52.4%) 18 (13.7%) 5 (23.8%) Cigarette/ day 5-18 19-32 33-46 47-60 0 (0%) 0 (19%) 23(17.6%) 7 (33.3%) 47 (35.9%) 7 (33.3%) 61 (46.6%) 7 (33.3%) Table 5: Risk factors for ischemic heart disease, results of the logistic univariate regression analysis. Risk Factors OR 95% CR P- value COPD 1.18 0.71-1.96 0.019 Gender 0.83 0.52 – 1.33 0.45 Age 1.14 0.90-1.44 0.19 Hypertension 7.77 4.71-12.82 0.001 Diabetes 4.52 2.77-7.37 0.001 Smoking 0.91 0.63 – 1.43 0.52 Dyslipidemia 17.05 9.72- 29.89 0.001 https://doi.org/10.15218/ejnm.2019.12 Erbil j. nurs. midwifery, Vol. 2, No. (2), Nov, 2019 Original Article As revealed by the results of the present study, the mean age of case and control groups was similar. In a study conducted by de Lucas-Ramos et al. (2008), it was ob- served that patients in the COPD group were older than those in the control group [8]. The results also indicated that the two groups were not significantly different in terms of their sex. This finding is in agree- ment with other previously conducted studies [8, 1]. Moreover, no significant difference was observed between the two groups regarding their BMI. This finding is not similar to the study conducted by de Lucas-Ramos et al. (2012) who reported that the patients with COPD and controls had different BMI [1]. This difference might be related to the difference between the two studies in terms of their sample size. It was also seen that smoking among COPD patients was not a risk factor for cardiovas- cular diseases, because as seen in Table 1, there was no significant difference be- tween the two groups in terms of their pack-years. This finding is not in agreement with those of the study carried out by de Lucas-Ramos et al. (2012) [1]. According to the results, FEV, FVC and FEV/FVC were significantly different in the two groups. Similar findings have been reported in pre- viously conducted studies [12, 13]. The results of the present study also showed that there was a significant differ- ence between the patients with COPD and the control group patients in terms of most of the comorbidities including hyperten- sion, diabetes, ischemic heart disease, heart failure, dyslipidemia, and lung can- cer. This finding is in agreement with those of the studies conducted by de Lucas- Ramos et al. (2012), López Varela et al. (2013), and Chatila et al. (2008) [1, 14, 15]. However, the two groups were not signifi- cantly different in terms of some comorbidities such as stroke, anemia, and low dietary intake. This finding is not in agreement with the one reported by de Lucas-Ramos et al. (2012) who reported a significant difference between the COPD patients and the controls regarding anemia [1]. According to the results of data analy- sis, there was a significant inverse relation- ship between decreased hypertension and stroke and increased severity of COPD. This finding is in agreement with those of the studies carried out by Imaizumi et al. (2015) and Shujaat et al. (2007) who re- ported that as severity of COPD rises, the levels of stroke and hypertension drop. This is could be due to small number of cases who were in stage III and IV [16, 17]. Other comorbidities; however, were not found to have a significant association with severity of COPD. Moreover, the results revealed that there is a significant relationship between is- chemic heart disease and diabetes melli- tus, hypertension, dyslipidemia, and ciga- rette smoking. Therefore, these comorbidi- ties can be regarded as risk factors for is- chemic heart disease. This finding is similar to the results of previously conducted studies [18-20].The results of data analysis in the present study also indicated that the risk of developing hypertension, diabetes mellitus, and dyslipidemia was significantly higher in patients with COPD compared to the control group. This finding is in agree- ment with the results of the previously conducted studies as well[1, 21, 22]. In conclusion, patients with COPD were confirmed to be at an increased risk of car- diovascular comorbidities, and there is a significant association between these two variables. However, the detailed mecha- nism of this relationship should be studied in the future studies. 98 Erbil Journal of Nursing & Midwifery COUNCLUSION DISCUSSION https://doi.org/10.15218/ejnm.2019.12 Erbil j. nurs. midwifery, Vol. 2, No. (2), Nov, 2019 Original Article ((English Edition)). 2008; 44(5):233-238. [7] Finkelstein J, Cha E, Scharf SM. Chronic ob- structive pulmonary disease as an independ- ent risk factor for cardiovascular morbidity. International Journal of Chronic Obstructive Pulmonary Disease. 2009; 4: 337-349. [8] Tanaka K, Senjyu H, Tawara Y, Tanaka T, Asai M, Tabusadani M, et al. Effects of Systematic Intervention for Chronic Obstructive Pulmo- nary Disease on Follow-up and Smoking Ces- sation Rates and Changes of the Pulmonary Function: A 7-year Longitudinal Study in a Japanese Rural City. Internal Medicine. 2018; 57(16): 2315-2323. [9] Chen W, Thomas J, Sadatsafavi M, FitzGerald JM. 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