Abnormal ankle-brachial index ABI has been found to be a strong predictor of mortality in some hemodialysis populations in studies with relatively short periods of follow-up, lower than 2 years. This study aimed to assess the predictive value of abnormal ABI as a risk factor for death among patients Abi jimenez maintenance hemodialysis after a 5-year follow-up. A total of patients on hemodialysis for at least 12 months were included in the study.
ABI measurement was performed using a mercury column sphygmomanometer and portable "Abi jimenez." Patients were divided into 3 groups according to ABI low: The prevalence rates of low, normal and high ABI were The "Abi jimenez" survival rate was lower in the groups with low ABI Abi jimenez regression was used to evaluate the association between ABI and mortality, adjusting for potential confounders. However, after adjustment for potential confounders, only low ABI persisted as an independent risk factor for all-cause mortality among hemodialysis patients.
In the presence of artery stenosis, a reduction in pressure occurs distally to the lesion.
Considering that the usefulness of ABI has already been demonstrated some hemodialysis populations with a mean follow-up lower than 2 years, 78 the present study aimed to assess
Abi jimenez predictive value of ABI as an independent risk factor for death among patients on maintenance hemodialysis after a 5-year follow-up. This is an observational prospective study, with a 5-year follow-up period, performed at six dialysis facilities in Rio de Janeiro State, Brazil.
All patients aged 18 to 75 years, who had been on hemodialysis for at least 12 months, were eligible to be included in the study.
Patients with cancer, anti-HIV positive test, atrial fibrillation, bilateral lower-limb amputation, or dementia and those who refused to participate were excluded from the study. ABI, defined as the ratio of ankle-to-arm Abi jimenez blood pressure, was measured once, Abi jimenez the entrance of the patients in the study, before hemodialysis session and after 5 minutes in supine position.
Standard blood pressure arm cuffs connected to a mercury column were applied to the arm and to each ankle with the lower end the bladder just above the malleoli.
Systolic blood pressure in the upper limb was measured on the brachial artery
Abi jimenez the arm contralateral to the vascular access. To calculate ABI, the lowest mean from the ankles was divided by the mean in the arm. All ABI measurements were performed by 3 trained observers one physician and two medical students based on the information that inter- and intra-observer variability for Doppler blood pressure measurement is negligible.
To evaluate the relationship Abi jimenez ABI and demographics, clinical and laboratory data, the population was divided into three groups according to ABI values: Demographics and clinical data were derived from both a structured clinical interview and a database used in all six dialysis facilities.
These data included gender, age, race, time on dialysis, primary kidney disease, vascular access, and current smoking status. Comorbidities were defined as following: Levels of C-reactive protein CRP were determined by ultra-sensitive immunoturbidimetric assay, specifically for the study, and the values shown were determined by the time ABI was measured. To better estimate the impact of bone mineral disturbances on our findings, cumulative exposure was assessed through calculation of the mean of all values for serum calcium, phosphorus and intact parathyroid hormone i-PTH measurements along the month period preceding the ABI evaluation or since hemodialysis initiation for patients on dialysis for less than 3 years, as described previously.
All routine blood analyses were performed in a central laboratory. "Abi jimenez" variables were presented as frequency.
Frequencies were compared by Fisher's exact test. The Kaplan-Meier test was used for analysis of survival, and comparison between curves was made by the
Abi jimenez test. Our study was designed to have a statistical power of 0. Associations of ABI group low, normal and high with death risk were analyzed by Cox-regression models: The software SPSS, version Of a total of 1, patients on maintenance hemodialysis in six dialysis facilities, patients were enrolled in the study.
Demographic and laboratory characteristics of Abi jimenez are listed in Table 1. Intact parathyroid hormone; HBsAg: The prevalence of low, normal and high ABI was Table 2 shows the characteristics of each ABI group.
Male gender prevailed in the Abi jimenez ABI group, when compared to the low and normal ones. No difference was found regarding arm blood pressure measurements between the groups. Hepatitis B Surface Antigens; Values are expressed by frequency and median range.
Abi jimenez findings of each group are shown in Table 3. After a 5-year follow-up period, of patients died, 69 lost their follow-up due to a change of dialysis facility and 28 underwent kidney transplantation.
The survival curves according to the ABI group are presented in Figure 1. When the 5-year survival rates were compared, values were lower in the groups of altered ABI Survival curves for the first 5 years of follow-up according to ankle-brachial index ABI at baseline. The association of ABI with mortality risk in the Cox proportional hazard models is shown in Table 4.
In the multivariate analysis, after adjustment for demographics and comorbidities Model 1low ABI persisted significantly associated with all-cause mortality HR1. Here, stroke sequelae HR 2. ABI is an easy, reliable and non-invasive test, that has been used as a diagnostic tool for PAD, a condition highly prevalent among hemodialysis patients.
The survival curves were significantly different between the ABI groups in the current study. Survival was lower in both low and high ABI groups when compared to the normal one.
These findings point to the importance usefulness of ABI as an important predictor of mortality in Abi jimenez population. Low ABI was found to be associated with higher mortality rate in general population 12 - 15 as well as in patients with chronic kidney disease, stages 3 to 5 19 and hemodialysis patients.
Abnormal values of ABI as predictors of death were assessed by Cox proportional hazards models. In the non-adjusted model, in which only Abi jimenez bands of ABI were taken into account, and the normal ABI band was taken as reference, only low ABI was associated with a significant death risk.
The multivariate analysis was performed in two steps. Firstly, we developed the Model 1, in which the association of "Abi jimenez" bands with mortality was adjusted for gender, age, race, diabetes status, time on dialysis, smoking, coronary disease, and stroke sequelae. On a second step, in Model 2, laboratory parameters were also added as potential confounding factors. Our findings showed that low ABI persisted as an independent risk factor for all-cause mortality even after adjustment for all demographics, comorbidities and Abi jimenez variables.
On the other hand, we found that high ABI did not represent an independent risk factor for all-cause mortality. This is in disagreement with previous studies, 820 but the small sample size in our analysis could have reduced the chance of detecting a true effect of high ABI due to the low statistical power.
Also interesting was the finding that diabetes, per se, did not an independent determinant for mortality. This finding is consistent with previous studies 2122 suggesting that only diabetic patients on hemodialysis having arterial disease present a greater risk of death. Moreover, diabetes was not a risk factor for death in hemodialysis when patients with PAD were excluded from the sample.
Age, baseline CRP levels and stroke sequelae were confirmed as independent risk factors for death during the 5-year follow-up period.
The first two variables are well-known risk factors for death in hemodialysis 2425confirming the association between a single baseline CRP measurement and long-term Abi jimenez risk. Stroke sequelae may represent the association between low ABI and diffuse atherosclerotic disease, and could be seen as a link between low ABI and high mortality rate in hemodialysis patients.
Among patients enrolled, the frequency of normal, low and high ABI was There was a predominance of males among patients with high ABI.
Patients in the Abi jimenez ABI group were older than those in the other two groups. The high prevalence of diabetes among low ABI patients could be attributed to the presence of macrovascular disease, whereas the predominance of
Abi jimenez in the group of high ABI could be explained by the greater prevalence of vascular calcification in diabetic patients.
Regarding hypertension, we did not detect significant differences between the ABI groups. We also found no association between smoking and the risk of abnormal ABI. Perhaps, the low prevalence of smoking in our population could have mitigated such effect.
Moreover, the absence of such correlation could be attributed to data collection strategy, since we considered only current smokers in our study. The association between smoking and PAD in hemodialysis patients was controversial in previous studies. The association between ABI and generalized atherosclerotic disease was also found in previous studies.
The positive correlation between atherosclerosis and inflammation, demonstrated in previous studies in both Abi jimenez population and hemodialysis patients 2829 could also be observed in our study, considering the variables CRP and serum albumin. This finding "Abi jimenez" also consistent with studies evaluating specifically PAD in both general population and hemodialysis patients. Ionized calcium, phosphorus and i-PTH levels were used to evaluate bone and mineral disturbances. It
Abi jimenez be stressed that, differently from other studies, we did not perform a merely cross-sectional analysis of the association between current ionized calcium and phosphorus levels and the presence of PAD.
In fact, in our study, calcium and phosphorus data represent the mean of values of monthly measurements of these variables during a long period of up to 36 months preceding ABI evaluation.
Thus, our data point against a direct association between hypercalcemia or hyperphosphatemia and ABI. A negative association of i-PTH levels with PAD, as well as with cardiac and aortic valve calcification "Abi jimenez" also found in previous studies.
Considering the high prevalence of PAD, its consequences and the current lack of effective therapies for hemodialysis patients, we think that the routine measurement of ABI could identify patients in higher long-term risk of death, who could benefit from early detection of PAD and interventions on risk factors associated with low ABI, such as inflammation, in attempt to change the apparently inexorable course of disease.
This study has some limitations that deserve consideration. Several established risk factors for PAD in general population, as smoking, could not be properly evaluated, since the data collection considered only the current state and not the total burden of exposition to it.
We also could not distinguish between overall and cardiovascular cause of mortality due to the lack of accurate information. Another limitation is that the studied population could not be representative of the national one a nationwide feature, since all patients are from Rio de Janeiro State. On Abi jimenez other side, the strengths of our study include the assessment of ABI by Doppler, the gold-standard method, its prospective design and the long follow-up period.
Most of similar studies observed patients for no more than 2 years.
There is no standardized definition for "long-term" concerning the follow-up in clinical research, but Abi jimenez meaning can be viewed as dependent on the disease, treatment and populations studied. Our findings showed a high frequency of "Abi jimenez" ABI among patients in hemodialysis.
In addition, the relatively higher risk of death for diabetic patients was reversed after adjustment for ABI. Potential Conflict of Interest. No potential conflict of interest relevant to this article was reported. National Center for Biotechnology InformationU.