Diabetes Mellitus
Cardiovascular Complications in Diabetic Patients Undergoing Regular Hemodialysis: A 5-Year Observational Study
Angiology 2015, Vol. 66(3) 225-230 ª The Author(s) 2014 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003319714523672 ang.sagepub.com
Hassan Al-Thani, MB, ChB, FRCS1, Adel Shabana, MD2, Ahmed Hussein, MB, ChB1, Ahmed Sadek, MB, ChB1, Ahmed Sharaf, MB, ChB1, Valsa Koshy, RN1, and Ayman El-Menyar, MB, ChB, MSc, FRCP, FESC, FACC3,4,5
Abstract We aimed to study the vascular outcomes in hemodialysis (HD) patients based on their diabetic status. A cohort observational study was conducted among patients undergoing regular HD with a 5-year follow-up. Of the 252 consecutive HD patients, 60% were diabetic. Compared with nondiabetics, diabetics were 11 years older, 4 years lesser on HD, and more likely to have prior cerebrovascular and coronary artery disease (CAD). Overall 5-year follow-up showed that diabetic patients had higher rates of HD vascular accesses (57% vs 41%, P ¼ .01), CAD (64% vs 33%, P ¼ .001), major amputations (8.6% vs 0%, P ¼ .003), and mortality (66% vs 23%, P ¼ .001). On multivariate analysis, independent predictors of mortality included number of vascular accesses in nondiabetics and HD duration, CAD, and peripheral artery disease in diabetic patients. Diabetes mellitus is associated with a significant vascular burden and mortality among HD patients. Moreover, our finding highlights the vascular impact of renal failure and HD. Keywords diabetes mellitus, end-stage renal failure, hemodialysis, vascular diseases, mortality
Introduction Diabetes mellitus (DM) is a common disease, comprising 4% to 8% of the general population and up to 45% of new dialysis patients in developed countries.1 According to the United States Renal Data System (USRDS), there is more than a 2-fold increase in the annual incidence of diabetic patients who require renal replacement therapy (RRT).2 Similar trends have been reported from other countries.3 According to the International Diabetes Federation, the Gulf Corporation Council countries, including the state of Qatar, have one of the highest prevalence of DM.4 Previous estimates of diagnosed DM in Qatar ranged from 12% (all residents) to 17% (among Qatari only) while another 10% were characterized as ‘‘prediabetes.’’5,6 Diabetic nephropathy (DN), as a major cause of renal impairment, is a progressive disease, which occurs due to direct as well as indirect effects of hyperglycemia.7 Diabetic nephropathy is a serious public health concern and is associated with increased cardiovascular (CV) morbidity and mortality.7 Reports from the United States and other Western countries demonstrated that several individuals with DN progress to endstage renal disease (ESRD) and required RRT including dialysis and transplantation.8-10 The differences in the incidence of DN in certain regions may be attributed to ethnic and racial
factors. Earle et al11 observed an increased incidence of DN among patients of Indo-Asian and African-Caribbean origin compared with caucasians. Since a significant population of patients with ESRD have DM as a major comorbidity, it is critical to understand the longitudinal association of DM with cause-specific mortality among hemodialysis (HD) patients.12 Several reports have demonstrated an increased risk of mortality with prolonged DM among HD patients.12-16 Vascular mortality was the main cause of death in this population, rather than mortality from infections.12 In patients with DM, the CV mortality may be explained by the end-organ damage or mediators of inflammation and oxidative stress. Oxidative stress and production of advanced glycosylated products might result
1
Department of Vascular Surgery, Hamad General Hospital, Doha, Qatar Cardiology, Faculty of Medicine, Ain-Shams University, Cairo, Egypt 3 Cardiology, Internal Medicine, Ahmed Maher Teaching Hospital, Cairo, Egypt 4 Clinical Medicine, Weill Cornell Medical School, Doha, Qatar 5 Clinical Research, Trauma Surgery, Hamad General Hospital, Doha, Qatar 2
Corresponding Author: Ayman El-Menyar, Clinical Research, Trauma Surgery, Hamad General Hospital, PO Box 3050, Doha, Qatar. Email: [email protected]
226 in endothelial dysfunction and increased CV risk.17,18 The association of CV outcomes in patients with DN undergoing HD has not been extensively reported in the Middle East. The present study aimed to assess the mortality and vascular outcomes in diabetic patients who were on regular HD for ESRD in Qatar.
Methods
Angiology 66(3) compare the duration of HD between the 2 groups. Association between baseline variables (age, gender, DM and duration of DM, diabetic retinopathy, hypertension, smoking, obesity, and dyslipidemia) were performed by logistic regression analysis to detect the predictors of vascular outcomes and data were presented using odds ratios (ORs) and 95% confidence interval. A 2-tailed P < .05 was considered significant. Data analysis was carried out using the SPSS version 18 (SPSS Inc, Chicago, Illinois).
Data were collected from the outpatient HD unit at Hamad Medical Corporation in the state of Qatar in 2007. We enrolled a cohort of 252 patients who were on regular HD for ESRD regardless of age, gender, or causality. Patients with incomplete data or who were on peritoneal dialysis were excluded. The study patients were categorized into 2 groups according to whether they had DM or not (diabetic patients vs nondiabetics). There was onsite regular follow-up during the HD dialysis sessions for almost 5 years. The study was approved by institutional review board committee (IRB# 12008/12) in Qatar. Data were collected by the attending physician, which includes clinical assessment, medical history, baseline demographics, laboratory investigations, and comorbidities.
Of the 252 consecutive HD patients, 55% were males and 60% were diabetics (n ¼ 152). The mean age of the patients was 57 + 15 years, and median HD duration was 5 years (range: 1-31 years). The most common risk factors were hypertension (84%), smoking (31%), obesity (28%), and dyslipidemia (25%). Of these patients, 44% were illiterate, 27% were retired, 12% were unmarried, and 8% were unemployed. The main causes of ESRD were DN (52%), primary glomerular disease (11%), vascular nephropathy (9%), and polycystic kidney disease (3.5%).
Definitions
Diabetes Mellitus Among the HD Population
The presence of DM was determined by the documentation in the medical records of a diagnosis of DM that had been treated with medication or insulin. The presence of hypertension was determined by any documentation in the medical record of hypertension or if the patient was on treatment. The presence of dyslipidemia was determined by a fasting cholesterol >5.2 mmol/L in the medical records or any history of treatment of dyslipidemia. Patients were considered to have peripheral artery disease (PAD) if they had 1 of the following criteria: ankle-brachial index (ABI)
Cardiovascular Complications in Diabetic Patients Undergoing Regular Hemodialysis: A 5-Year Observational Study
Angiology 2015, Vol. 66(3) 225-230 ª The Author(s) 2014 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003319714523672 ang.sagepub.com
Hassan Al-Thani, MB, ChB, FRCS1, Adel Shabana, MD2, Ahmed Hussein, MB, ChB1, Ahmed Sadek, MB, ChB1, Ahmed Sharaf, MB, ChB1, Valsa Koshy, RN1, and Ayman El-Menyar, MB, ChB, MSc, FRCP, FESC, FACC3,4,5
Abstract We aimed to study the vascular outcomes in hemodialysis (HD) patients based on their diabetic status. A cohort observational study was conducted among patients undergoing regular HD with a 5-year follow-up. Of the 252 consecutive HD patients, 60% were diabetic. Compared with nondiabetics, diabetics were 11 years older, 4 years lesser on HD, and more likely to have prior cerebrovascular and coronary artery disease (CAD). Overall 5-year follow-up showed that diabetic patients had higher rates of HD vascular accesses (57% vs 41%, P ¼ .01), CAD (64% vs 33%, P ¼ .001), major amputations (8.6% vs 0%, P ¼ .003), and mortality (66% vs 23%, P ¼ .001). On multivariate analysis, independent predictors of mortality included number of vascular accesses in nondiabetics and HD duration, CAD, and peripheral artery disease in diabetic patients. Diabetes mellitus is associated with a significant vascular burden and mortality among HD patients. Moreover, our finding highlights the vascular impact of renal failure and HD. Keywords diabetes mellitus, end-stage renal failure, hemodialysis, vascular diseases, mortality
Introduction Diabetes mellitus (DM) is a common disease, comprising 4% to 8% of the general population and up to 45% of new dialysis patients in developed countries.1 According to the United States Renal Data System (USRDS), there is more than a 2-fold increase in the annual incidence of diabetic patients who require renal replacement therapy (RRT).2 Similar trends have been reported from other countries.3 According to the International Diabetes Federation, the Gulf Corporation Council countries, including the state of Qatar, have one of the highest prevalence of DM.4 Previous estimates of diagnosed DM in Qatar ranged from 12% (all residents) to 17% (among Qatari only) while another 10% were characterized as ‘‘prediabetes.’’5,6 Diabetic nephropathy (DN), as a major cause of renal impairment, is a progressive disease, which occurs due to direct as well as indirect effects of hyperglycemia.7 Diabetic nephropathy is a serious public health concern and is associated with increased cardiovascular (CV) morbidity and mortality.7 Reports from the United States and other Western countries demonstrated that several individuals with DN progress to endstage renal disease (ESRD) and required RRT including dialysis and transplantation.8-10 The differences in the incidence of DN in certain regions may be attributed to ethnic and racial
factors. Earle et al11 observed an increased incidence of DN among patients of Indo-Asian and African-Caribbean origin compared with caucasians. Since a significant population of patients with ESRD have DM as a major comorbidity, it is critical to understand the longitudinal association of DM with cause-specific mortality among hemodialysis (HD) patients.12 Several reports have demonstrated an increased risk of mortality with prolonged DM among HD patients.12-16 Vascular mortality was the main cause of death in this population, rather than mortality from infections.12 In patients with DM, the CV mortality may be explained by the end-organ damage or mediators of inflammation and oxidative stress. Oxidative stress and production of advanced glycosylated products might result
1
Department of Vascular Surgery, Hamad General Hospital, Doha, Qatar Cardiology, Faculty of Medicine, Ain-Shams University, Cairo, Egypt 3 Cardiology, Internal Medicine, Ahmed Maher Teaching Hospital, Cairo, Egypt 4 Clinical Medicine, Weill Cornell Medical School, Doha, Qatar 5 Clinical Research, Trauma Surgery, Hamad General Hospital, Doha, Qatar 2
Corresponding Author: Ayman El-Menyar, Clinical Research, Trauma Surgery, Hamad General Hospital, PO Box 3050, Doha, Qatar. Email: [email protected]
226 in endothelial dysfunction and increased CV risk.17,18 The association of CV outcomes in patients with DN undergoing HD has not been extensively reported in the Middle East. The present study aimed to assess the mortality and vascular outcomes in diabetic patients who were on regular HD for ESRD in Qatar.
Methods
Angiology 66(3) compare the duration of HD between the 2 groups. Association between baseline variables (age, gender, DM and duration of DM, diabetic retinopathy, hypertension, smoking, obesity, and dyslipidemia) were performed by logistic regression analysis to detect the predictors of vascular outcomes and data were presented using odds ratios (ORs) and 95% confidence interval. A 2-tailed P < .05 was considered significant. Data analysis was carried out using the SPSS version 18 (SPSS Inc, Chicago, Illinois).
Data were collected from the outpatient HD unit at Hamad Medical Corporation in the state of Qatar in 2007. We enrolled a cohort of 252 patients who were on regular HD for ESRD regardless of age, gender, or causality. Patients with incomplete data or who were on peritoneal dialysis were excluded. The study patients were categorized into 2 groups according to whether they had DM or not (diabetic patients vs nondiabetics). There was onsite regular follow-up during the HD dialysis sessions for almost 5 years. The study was approved by institutional review board committee (IRB# 12008/12) in Qatar. Data were collected by the attending physician, which includes clinical assessment, medical history, baseline demographics, laboratory investigations, and comorbidities.
Of the 252 consecutive HD patients, 55% were males and 60% were diabetics (n ¼ 152). The mean age of the patients was 57 + 15 years, and median HD duration was 5 years (range: 1-31 years). The most common risk factors were hypertension (84%), smoking (31%), obesity (28%), and dyslipidemia (25%). Of these patients, 44% were illiterate, 27% were retired, 12% were unmarried, and 8% were unemployed. The main causes of ESRD were DN (52%), primary glomerular disease (11%), vascular nephropathy (9%), and polycystic kidney disease (3.5%).
Definitions
Diabetes Mellitus Among the HD Population
The presence of DM was determined by the documentation in the medical records of a diagnosis of DM that had been treated with medication or insulin. The presence of hypertension was determined by any documentation in the medical record of hypertension or if the patient was on treatment. The presence of dyslipidemia was determined by a fasting cholesterol >5.2 mmol/L in the medical records or any history of treatment of dyslipidemia. Patients were considered to have peripheral artery disease (PAD) if they had 1 of the following criteria: ankle-brachial index (ABI)
