THE METABOLIC SYNDROME IN PATIENTS ON PERITONEAL DIALYSIS : PREVALENCE AND INFLUENCE ON CARDIOVASCULAR MORBIDITY

< e metabolic syndrome (MS) is a multi-factorial disorder which includes a main risk factors associated with the development of cardiovascular, neurologic, renal and endocrine diseases, especially type  diabetes. < is study has been conducted to estimate the prevalence of the MS in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and its association with cardiovascular morbidity. < e study included  patients ( type  diabetic patients and  non-diabetic patients), who had been on peritoneal dialysis for >  months. At the beginning of CAPD treatment (baseline) and at the end of follow-up, we measured: body mass index (BMI), blood pressure, fasting blood glucose, triglycerides and high-density lipoprotein cholesterol (HDLC) and defi ned the prevalence of the MS using the modifi ed National Cholesterol Education Program (NCEP; Adult Treatment Panel III) for peritoneal dialysis patients. < e overall prevalence of the MS was ,. < e metabolic syndrome was estimated in all () type  diabetic patients (vs.  patients on the beginning of CAPD treatment). In non-diabetic peritoneal patients, the MS was estimated in  cases, according to , at the beginning CAPD treatment. Development of the MS was signifi cantly higher in the type  diabetic patients in compared with non-diabetic patients until the end of follow-up examination (p=,). < e prevalence of LVH in type  diabetic patients with the MS was signifi cantly higher (p=,) than in non-diabetic peritoneal patients with the MS. We didn’t found statistical signifi cantly diff erence in the prevalence of ischemic heart disease between this two category of peritoneal dialysis patients (p=,). < e results indicate that the metabolic syndrome is presented in high percentage in peritoneal dialysis patients, and it’s also important risk factor of high cardiovascular morbidity rate in these patients, especially in type  diabetic patients.


Introduction
The metabolic syndrome (MS) is rapidly becoming a primary cause of morbidity and mortality in the general population (). is syndrome is characterized by the variable coexistence of hyperinsulinemia, obesity, dyslipidemia, hyperglycemia and hypertension.Other conditions associated with the syndrome include microalbuminuria, infl ammation, a protrombotic state and fatty liver.Subjects with the metabolic syndrome are, at essentially, with double risk to develop cardiovascular disease compared with those without the syndrome ().It further raises the risk for type  diabetes by about -fold ().Cardiovascular morbidity and mortality are common in peritoneal dialysis patients.The prevalence of the MS in peritoneal dialysis patients is a subject of recent studies (,).Although, some of the MS component are strongly associated with cardiovascular morbidity and mortality (,), association of the metabolic syndrome with cardiovascular morbidity and mortality in peritoneal dialysis patients is nor clearly establishment.Aim of this study was to estimate the prevalence of the MS in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and its association with cardiovascular morbidity.

Materials and Methods
The study included  patients, which had been on peritoneal dialysis for more than  months.Twenty fi ve patients were type  diabetic patients aged - years and  non-diabetic patients aged - years.At the beginning of CAPD treatment (baseline) and at the end of follow-up, we measured: body mass index (BMI), blood pressure, fasting blood glucose, triglycerides and high-density lipoprotein cholesterol (HDL-C) due to defi ned the prevalence of the MS and its associated with cardiovascular morbidity.The definition of the MS is based on the co-occurrence of the three or more risk factors using the Modifi ed National Cho-lesterol Education Program (NCEP; Adult Treatment Panel III) for peritoneal dialysis patients (), (Table ).Left ventricular hypertrophy (LVH) was estimated by echocardiographic examination.Left ventricle hypertrophy was defined by a left ventricular mass index (LVMI) of over  g/m in man or > g/ m in a woman according to recommendations of the American Society of Echocardiography.Ischemic heart disease was determinated by electrocardiographic examination, antecedents of angina or myocardial infarction.

Statistical analysis
Categorial data were presented as percentages.Diff erences in categorial data were compared with the chisquare (χ  ) test.e p-value < , was considered signifi cant.

Results
At the beginning of peritoneal dialysis treatment,  of  type  diabetic patients () didn't have any elements of the MS.Six () patients in this group had  risk factors,  patients were with  risk factors (), and one of them () had all of fi ve risk factors of the MS (Table ).In non-diabetic patients group , cases had no criteria of the MS at the beginning of peritoneal dialysis treatment.It was not determined the significant difference in presence of the MS comparing that two groups of patients at the beginning of CAPD treatment (χ=,, p=,).At the end of follow-up, the metabolic syndrome was estimated in all type  diabetic patients ().In the same group  patients had five risk factors,  patients had four risk factors and only  patients had three risk factors of the MS.The prevalence of the MS in type  diabetic patients undergoing peritoneal dialysis was signifi cantly higher than at the beginning of renal replacement therapy (χ =,; p=,).At the end of follow-up, the MS was estimated in  of non-diabetic peritoneal patients, more of them with three risk factors (,).Significant difference in the prevalence of the MS in this category of peritoneal dialysis patients was not found between beginning and follow-up period (χ =,, p=,).Development of the MS was significantly higher in the type  diabetic patients compared with non-diabetic patients until the end of follow-up examination (χ=,, p=,), (Table ).The overall prevalence of the MS in peritoneal dialysis patients was ,.Ischemic heart disease was manifested in / () type  diabetic patients with the MS presenting with - risk factors.Blood pressure elevation (,) and blood glucose abnormalities (,) were the most frequent, while lower value of HDL-C was the least frequent component (,).The prevalence of LVH was  (/) in the group of type  diabetic patients with the MS.All cardiovascular mortality was  in the same group of patients.
In non-diabetic peritoneal patients with the MS, ischemic heart disease was presented in  patients, LVH in , patients, while , patients didn't have electrocardiographic and echocardiographic changes.e prevalence of LVH in type  diabetic patients with the MS was signifi cantly higher (p=,) than in non-diabetic peritoneal patients with the MS (Table ).There was no difference in the preva-lence of ischemic heart disease between this two category of peritoneal dialysis patients (p=,).

Discussion
The metabolic syndrome represents a clustering of metabolic risk factors for development of cardiovascular disease.The available evidence indicates that between  to  of the world's general population have features of metabolic syndrome ().Because of this relatively high prevalence, the metabolic syndrome accounts for an increasing proportion of cardiovascular risk worldwide.Despite its high prevalence, little is known of the prospective association of the metabolic syndrome with cardiovascular morbidity and mortality in peritoneal dialysis patients.Chronic ambulatory peritoneal dialysis is associated with a number of metabolic abnormalities.These include lipid abnormalities, especially hypertriglyceridemia, carbohydrate abnormalities resulting of the large glucose absorption from peritoneal dialysate, protein depletion, obesity etc. ().Although some of these metabolic abnormalities are separately strong cardiovascular risk factor, links among different conditions and components appear to be an independent and aggravating risk factor for cardiovascular diseases.e dialysis population has a much higher risk of cardiovascular mortality compared with the general population ().e patients with chronic kidney disease stages  and  with the metabolic syndrome have a signifi cantly higher risk mortality compared to those without the metabolic syndrome ().In a study by a Johnson's group (), the prevalence of the MS was highest among those on peritoneal dialysis ().Patients on peritoneal dialysis compared with those on haemodialysis might be more at risk for the MS due to impaired glucose regulation.It is known that peritoneal dialysis solutions contain large quantities of glucose and - of the glucose installed into the peritoneal cavity is absorbed, corresponding to - g of glucose per day ().That should be alert to the development of the MS among patients undergoing peritoneal dialysis.Young et al. () examined the prevalence of the MS at the time of renal replacement therapy initiation in a group of  incident dialysis patients ( haemodialysis and  peritoneal dialysis) using NCEP criteria and found that the overall prevalence of the MS was , in that population.Another recent study showed the prevalence of the MS of , among cohort of  peritoneal dialysis patients ().
The prevalence of the MS in our study was highly ,.At the beginning of continuous ambulatory peritoneal dialysis treatment, the prevalence of the MS was higher in type  diabetic patients than in nondiabetic peritoneal patients, but without significant difference (p=,).During to follow-up, the MS has been noted significantly more in the type  diabetic patients than in non-diabetic patients (p=,).
The results of a large number of cross-sectional and longitudinal studies confirmed the unfavorable impact of the metabolic syndrome on cardiovascular risk profile and associated of the metabolic syndrome with an increased risk of cardiovascular disease and death in general population (, ).Kwan et al. found that the -year cardiovascular survival for patients on peritoneal dialysis with and without the metabolic syndrome was  and , ().A considerable number of studies have demonstrated that modifi cations of the left ventricular structure take place in a considerable proportion of patients with the metabolic syndrome ().We found that  of type  diabetic peritoneal dialysis patients with the MS and , of non-diabetic peritoneal dialysis patients with the MS showed left ventricular hypertrophy.e prevalence of LVH was signifi cantly higher in type  diabetic patients with the MS (p=,).is fi nding emphasizes that the metabolic syndrome in peritoneal dialysis patients is important factor for the development or progression of cardiac organ damage.e increased cardiovascular risk profi le of the metabolic syndrome might be interplayed between metabolic factors (such as hyperglycemia, hyperinsulinaemia) and other non-metabolic factors (haemodynamic and non-haemodynamic).Ischemic heart disease was found in  of type  diabetic peritoneal dialysis patients with the MS and  of non-diabetic peritoneal dialysis patients with the MS, but without significantly difference (p=,).Therefore, there is a strong reason for intensive risk factor modification of the metabolic syndrome in peritoneal dialysis patients and intervention programme for multiple risk factors.

Conclusion
e metabolic syndrome is common in peritoneal dialysis patients with the prevalence of ,.-e prevalence of the metabolic syndrome signifi cantly increases in type  diabetic patients undergoing CAPD treatment.
-Left ventricular remodeling is much higher in type  diabetic patients with the metabolic syndrome undergoing peritoneal dialysis than in non-diabetic peritoneal dialysis patients.-e metabolic syndrome has important contribution to the risk of high cardiovascular morbidity rate in these patients.