Anemia and chronic kidney disease are potential risk factors for mortality in stroke patients: a historic cohort study

Risk factors for the outcome after thrombolysis in acute ischemic stroke - the prominent role of kidney dysfunction: A retrospective cohort observational study

A complex interplay of factors reflecting the general biological, cardiovascular, neurological, renal, and metabolic status of patients influences the outcome of thrombolysis in stroke patients. This is a retrospective cohort observational study aimed to determine the importance of kidney dysfunction among these factors. Data (demographic, lifestyle, physical examination, laboratory, imaging, including metabolic and cardiovascular risk factors and comorbidities, neurological scores, and outcomes) of all stroke patients who underwent thrombolysis have been registered since January 1, 2016, in an online database. A total of 296 patients registered until December 31, 2020, were included in the study. The National Institutes of Health Stroke Scale, modified Rankin scale, Barthel index, percentage of hemorrhagic transformation, and in hospital death were used to evaluate the neurological status and outcomes of the patients. Regression analysis, Mann-Whitney test, Fisher exact test, logistic regression, and multivariate analysis were used for statistical analysis. Kidney dysfunction, as reflected by the estimated glomerular filtration rate, was associated with in hospital death and all but one of the neurological scores. Other risk factors most frequently associated with neurological scores were age, international normalized ratio, and cognitive decline. Multivariate analysis revealed estimated glomerular filtration rate (as determined by chronic kidney disease-EPI equation) as a determinant for all but one of these scores, and as the most important determinant for most of them, except for those reflecting the pre-intervention neurological status of the patient. Kidney dysfunction seems to be the most important determinant of the outcome of thrombolysed stroke patients, a result obtained by no other study.

Association between magnesium intake and the risk of anemia among adults in the United States

Background

Magnesium deficiency is related to an increased risk of anemia, but epidemiological evidence supporting this association remains scarce. The purpose of the present survey was to evaluate the relationship between dietary magnesium intake and the risk of anemia.

Methods

In total, 13,423 participants aged 20-80 years were enrolled using data from the National Health and Nutrition Examination Survey 2011-2016. Magnesium consumption was evaluated using 24 h dietary recalls. Multivariable generalized linear models were developed to demonstrate the association between dietary magnesium intake and the prevalence of anemia.

Results

An inverse association between dietary magnesium intake and the risk of anemia was detected based on a full adjustment model. We evaluated magnesium intake as a categorical variable (five quartiles). Compared with the lowest value, the highest multivariate adjusted odds ratio (95% confidence interval) for anemia was 0.64 (0.46-0.89). Stratified analyses revealed a reverse relationship between magnesium intake and anemia in women. However, no significant association was observed in men (p _{for trend} = 0.376). A similar reverse association was found among the older group (aged ≥60 years).

Conclusion

Magnesium deficiency is closely related to a higher rate of anemia occurrence, especially among women and older Americans. Further larger-scale prospective studies are required to confirm these conclusions.

Association of chronic kidney disease with outcomes in acute stroke

Previous studies have found an association between chronic kidney disease and poor outcomes in stroke patients. However, there is a paucity of literature evaluating this association by stroke type. We therefore aimed to explore the association between CKD and stroke outcomes according to type of stroke. The data consisting of 594,681 stroke patients were acquired from Universal Coverage Health Security Insurance Scheme Database in Thailand. Binary logistic regression was used to assess the relationship of CKD and outcomes, which were as follows; in-hospital mortality, long length of stay (>3 days), pneumonia, sepsis, respiratory failure and myocardial infarction. Results: after fully adjusting for covariates, CKD was associated with increased odds of in-hospital mortality in patients with ischemic (OR 1.32; 95% CI = 1.27–1.38), haemorrhagic (OR 1.31; 95% CI = 1.24–1.39), and other undetermined stroke type (OR 1.44; 95% CI = 1.21–1.73). CKD was found to be associated with increased odds of pneumonia, sepsis, respiratory failure and myocardial infarction in ischaemic stroke. While CKD was found to be associated with increase odds of sepsis, respiratory failure, and myocardial infarction, decrease odds of pneumonia was observed in patients with haemorrhagic stroke. In other undetermined stroke type, CKD was found to only be associated with increase odds of sepsis and respiratory failure, while there is no significant association of CKD and increase or decrease odds with pneumonia and myocardial infarction. CKD was associated with poor outcomes in all stroke types. CKD should be considered as part of stroke prognosis as well as identifying at risk patient population for in-hospital complications.

Relationship between Self-Reported Sleep Duration and Risk of Anemia: Data from the Korea National Health and Nutrition Examination Survey 2016-2017

The importance of sleep has been gaining more and more attention nowadays. It has been widely studied that some major health issues, such as cardiovascular diseases or mortality, are closely related to the extreme ends of sleep durations. Anemia is one of the health problems in modern society. In this study, we aimed to find a relationship between anemia occurrence and sleep duration. Data of 11,131 Korean adults aged 19 years or older were recruited from the 2016-2017 Korea National Health and Nutrition Examination Survey and analyzed in this cross-sectional study. 'Anemia' was defined in this study by hemoglobin level of <13 g/dL in men and <12 g/dL in women. Selected data were sorted into five groups by sleep duration: <5 h, 5 h ~ <6 h, 6 h ~ <8 h, 8 h ~ <9 h, and ≥9 h per day. We performed multivariate logistic regression analysis to assess the relationship between sleep duration and risk of anemia after adjusting for covariates including age, gender, family income level, education level, physical activity, cigarette smoking, and alcohol usage. Other factors were assessed in the analysis, such as depression, hypertension, diabetes, dyslipidemia, stroke, coronary artery disease, malignancy, stress level, and body mass index (BMI). We found that sleep duration of <5 h was related to high risk of anemia (odds ratio = 1.87; 95% confidence interval = 1.01-3.49, sleep duration of 6 h ~ <8 h as the reference group). Also, sleep duration of ≥9 h was related to lower risk of anemia in most premenopausal women after adjusting for covariates (odds ratio = 0.61; 95% confidence interval = 0.38-0.96, sleep duration of 6 h ~ < 8 h as the reference group). Male individuals with sleep durations of <5 h (odds ratio = 2.01; 95% confidence interval =1.05-3.84) and of ≥9 h (odds ratio = 2.48; 95% confidence interval =1.63-3.81) had a significantly higher risk of anemia without covariate adjustment. Postmenopausal women with sleep durations of ≥9 h had a significantly higher risk of anemia (odds ratio =2.02; 95% confidence interval =1.33-3.08) without adjusting for covariates. However, the associations became statistically insignificant after adjusting for age and covariates in both men and postmenopausal women. In conclusion, we found significant associations between extreme ends of sleep duration and risk of anemia in premenopausal Korean women. However, we did not observe strong associations between self-reported sleep duration and anemia risk in men or postmenopausal women.

Stroke Mortality Outcomes in Uganda

BACKGROUND AND PURPOSE

Stroke outcome data in Uganda is lacking. The objective of this study was to capture 30-day mortality outcomes in patients presenting with acute and subacute stroke to Mbarara Regional Referral Hospital (MRRH) in Uganda.

METHODS

A prospective study enrolling consecutive adults presenting to MRRH with abrupt onset of focal neurologic deficits suspicious for stroke, from August 2014 to March 2015. All patients had head computed tomography (CT) confirmation of ischemic or hemorrhagic stroke. Data was collected on mortality, morbidity, risk factors, and imaging characteristics.

RESULTS

Investigators screened 134 potential subjects and enrolled 108 patients. Sixty-two percent had ischemic and 38% hemorrhagic stroke. The mean age of all patients was 62.5 (SD 17.4), and 52% were female. More patients had hypertension in the hemorrhagic stroke group than in the ischemic stroke group (53% vs. 32%, p = 0.0376). Thirty-day mortality was 38.1% (p = 0.0472), and significant risk factors were National Institutes of Health Stroke Scale (NIHSS) score, female sex, anemia, and HIV infection. A one unit increase of the NIHSS on admission increased the risk of death at 30 days by 6%. Patients with hemorrhagic stroke had statistically higher NIHSS scores (p = 0.0408) on admission compared to patients with ischemic stroke, and also had statistically higher Modified Rankin Scale (mRS) scores at discharge (p = 0.0063), and mRS score change from baseline (p = 0.04).

CONCLUSIONS

Our study highlights an overall 30-day stroke mortality of 38.1% in southwestern Uganda, and identifies NIHSS at admission, female sex, anemia, and HIV infection as predictors of mortality.

Estimated glomerular filtration rate, anemia and outcomes in patients with ischemic stroke

Background

Anemia is highly prevalent in patients with low estimated glomerular filtration rate (eGFR). However, the combined effect of anemia and low eGFR on the prognosis of stroke has not been well studied.

Methods

Data of patients with acute ischemic stroke in the prospective cohort study of China National Stroke Registry was reviewed. According to the levels of eGFR and hemoglobin, patients were categorized into four groups: low eGFR (<60 mL/min per 1.73 m²) or normal eGFR (≥60 mL/min per 1.73 m²) with or without anemia. Multivariate logistic regression methods were used to analyze the association between eGFR with or without anemia and outcomes after stroke [the poor functional outcome (modified Rankin Scale, mRS 3-6), mortality and stroke recurrence] at 3 months and 1 year.

Results

This study included 8,303 stroke patients. After adjusting for the confounding factors, low eGFR with normal hemoglobin increased the risk of mortality at 1 year of follow-up [odds ratio (OR) =1.50; 95% confidence interval (95% CI), 1.14-1.97]. Anemia with normal eGFR was not associated with any poor outcome at 1-year of follow-up. In patients with both low eGFR and anemia, there was an increased risk of 1-year poor functional outcome (OR 1.73; 95% CI, 1.30-2.29), mortality (OR 2.64; 95% CI, 1.94-3.59) and stroke recurrence (OR 1.42; 95% CI, 1.06-1.91). Combined and interactive effects of the pattern of low eGFR and anemia on the poor functional outcome (P for interaction =0.02) and all-cause mortality (P for interaction =0.046) were observed.

Conclusions

Ischemic stroke patients with concurrent low eGFR and anemia increased risks of poor functional outcome, mortality and stroke recurrence after 1-year follow-up.

Prevalence Of Anemia And Its Associated Factors Among Chronic Kidney Disease Patients At University Of Gondar Hospital, Northwest Ethiopia: A Hospital-Based Cross Sectional Study

BACKGROUND

Chronic kidney disease (CKD) is a global public health problem associated with progressive decline in kidney function and adverse cardiovascular outcome. Anemia of CKD has substantial adverse outcomes in CKD patients. There is paucity of published data on prevalence of anemia and its associated factors among CKD patients in Northwest Ethiopia.

OBJECTIVE

This study aimed to determine the prevalence of anemia and its associated factors among CKD patients at the University of Gondar hospital, Northwest Ethiopia.

METHODS

A hospital-based cross-sectional study was conducted from May 1, to September 30, 2018. Consecutive sampling was used to recruit 251 study subjects. Patients were interviewed to obtain demographic data, and the patients' medical records were reviewed to obtain information on relevant medical history and laboratory parameters. Data was analyzed using SPSS version 20. Bivariate and multivariate logistic regression analyses were used to identify independently associated factors of anemia among CKD patients. P-value <0.05 was used to declare association.

RESULTS

The overall prevalence of anemia in CKD patients was high (64.5%), and the magnitude worsened as kidney function declined. Hypertension (45%), chronic glomerulonephritis (24%) and diabetes (20%) were common causes of CKD. Multivariate logistic regression analysis revealed rural residence (AOR= 2.75, 95%CI: 1.34-5.65, P=0.006), BMI <18.5 kg/m2 (AOR=6.78, 95%CI: 1.32-34.73, P=0.022) and BMI of 18.5-24.9 kg/m2 (AOR=5.04, 95%CI: 1.26-20.10, P=0.022), and having hemodialysis history (AOR=3.59, 95%CI: 1.24-10.38, P=0.018) were independently associated with anemia among CKD patients.

CONCLUSION

Periodic screening and intervention programs for anemia of CKD should be practiced to change the existing situation in the setting.

Association between Dietary Mineral Intake and Chronic Kidney Disease: The Health Examinees (HEXA) Study

Few studies have explored the association between mineral intake and chronic kidney disease (CKD). A cross-sectional analysis investigated the association between mineral intake (calcium, phosphorus, sodium, potassium, iron, and zinc) and CKD using the Health Examinee (HEXA) cohort of the Korean Genome and Epidemiologic Study (KoGES). For 159,711 participants, mineral intake was assessed by a food frequency questionnaire. CKD was defined as an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m². Dietary intake of each mineral was divided into quartiles and the quartile including recommended dietary allowance (RDA) or adequate intake (AI) of each mineral was used as a reference. We assessed the association between the quartile of mineral intakes and CKD using polytomous logistic regression models. The lowest quartiles of phosphorus (≤663.68 mg/day, odds ratio [OR] = 1.64, 95% confidence interval [CI]: 1.25–2.15), potassium (≤1567.53 mg/day, OR = 1.87, 95% CI: 1.27–2.75), iron (≤6.93 mg/day, OR = 1.53, 95% CI: 1.17–2.01), and zinc (≤5.86 mg/day, OR = 1.52, 95% CI: 1.02–2.26) were associated with higher odds for advanced CKD compared with the references. The present study suggests that an inadequate intake of some minerals may be associated with CKD occurrence in the general population. Due to the reverse causation issue in this cross-sectional study design, further longitudinal prospective studies are needed in order to prove the results.

Moderate to Severe Anemia Is Associated with Poor Functional Outcome in Acute Stroke Patients Treated with Mechanical Thrombectomy

Background

Anemia will negatively affect cerebral collaterals and penumbra. Eventually, it may cause worse clinical outcomes and even increase mortality rates in stroke patients. Anemia has recently been suggested to be an independent risk factor for ischemic stroke. Therefore, we aimed to investigate the effects of the presence of anemia on clinical outcomes in ischemic stroke patients undergoing mechanical thrombectomy.

Methods

This was a retrospective study involving the prospectively and consecutively collected data of 90 adult patients between January 2015 and August 2016. Hemoglobin (Hb) cutoff levels were accepted as 12 g/dL for women and 13 g/dL for men. Patients having anemia were further divided into three subgroups as severe anemia (Hb <8 g/dL for both genders), moderate anemia (Hb <10 g/dL for both genders), and mild anemia (Hb <13 g/dL for men and Hb <12 g/dL for women).

Results

Forty of the subjects (44.4%) had anemia. Moderate anemia was detected in 14 out of 90 patients (15.5%) and severe anemia was found in only four of them (4.4%). Poor functional outcome (mRS 3-6) was similar in both anemic and non-anemic patients (37.5% vs. 38%, respectively, p = 0.08), but poor functional outcome was found to be statistically significant with severe anemic group (Hb <8 mg/dL) (p = 0.003). In multiple logistic regression analysis, moderate and severe anemia has been found to increase the mortality (p = 0.032).

Conclusions

Our study demonstrated a poor functional outcome only in moderate to severe anemic patients. Clinicians should keep in mind the negative effect of moderate to severe anemia in the clinical course of acute stroke patients treated with mechanical thrombectomy.

Impact of Hemoglobin Levels and Anemia on Mortality in Acute Stroke: Analysis of UK Regional Registry Data, Systematic Review, and Meta-Analysis

BACKGROUND

The impact of hemoglobin levels and anemia on stroke mortality remains controversial. We aimed to systematically assess this association and quantify the evidence.

METHODS AND RESULTS

We analyzed data from a cohort of 8013 stroke patients (mean±SD, 77.81±11.83 years) consecutively admitted over 11 years (January 2003 to May 2015) using a UK Regional Stroke Register. The impact of hemoglobin levels and anemia on mortality was assessed by sex-specific values at different time points (7 and 14 days; 1, 3, and 6 months; 1 year) using multiple regression models controlling for confounders. Anemia was present in 24.5% of the cohort on admission and was associated with increased odds of mortality at most of the time points examined up to 1 year following stroke. The association was less consistent for men with hemorrhagic stroke. Elevated hemoglobin was also associated with increased mortality, mainly within the first month. We then conducted a systematic review using the Embase and Medline databases. Twenty studies met the inclusion criteria. When combined with the cohort from the current study, the pooled population had 29 943 patients with stroke. The evidence base was quantified in a meta-analysis. Anemia on admission was found to be associated with an increased risk of mortality in both ischemic stroke (8 studies; odds ratio 1.97 [95% CI 1.57-2.47]) and hemorrhagic stroke (4 studies; odds ratio 1.46 [95% CI 1.23-1.74]).

CONCLUSIONS

Strong evidence suggests that patients with anemia have increased mortality with stroke. Targeted interventions in this patient population may improve outcomes and require further evaluation.

Acute ischemic stroke and abnormal blood hemoglobin concentration

OBJECTIVES

This study examines whether low or high blood hemoglobin concentration (HGB) is associated with stroke severity, worse clinical outcomes, and poorer prognosis after acute ischemic stroke (AIS).

METHODS

This retrospective cohort study included data from the Ontario Stroke Registry on consecutive patients with AIS who were admitted between July 2003 and March 2008. We excluded patients taking anticonvulsants or iron supplement; patients with cancer, renal failure, history of gastro-intestinal or genitourinary bleeding, and pregnancy. Patients were divided into groups as follows: low HGB, normal HGB, and high HGB. Outcome measures included the frequency of greater degree of disability at discharge (modified Rankin score: 3-6), 7-day, 30-day and 90-day mortality, and length of stay in the acute stroke care hospital.

RESULTS

Hemoglobin levels higher than the upper limit of normal are associated with a greater disability at discharge (OR = 1.49, 95% CI: 1.03-2.15, P = 0.0331), and higher 30-day mortality (HR = 1.98, 95% CI: 1.44-2.74, P < 0.0001) after adjustment for major potential confounders. The Kaplan-Meier curves indicate that abnormal HGB levels are associated with higher mortality after AIS (P < 0.0001). HGB levels below the lower limit of normal are associated with longer lengths of stay in the acute care hospital (OR = 1.11, 95% CI: 1.02-1.22, P = 0.017). Elevated HGB was associated with greater neurological deficit on admission (OR = 1.45, 95% CI: 1.06-1.95, P = 0.0195).

CONCLUSIONS

Our results suggest that an elevated HGB on the initial admission is associated with more severe strokes, greater disability at discharge, and higher 30-day mortality after AIS. A low HGB on admission is associated with longer stay in the acute care hospital.

Anemia increases the mortality risk in patients with stroke: A meta-analysis of cohort studies

The impact of anemia on the outcome of patients with stroke remains inconsistent. We performed a meta-analysis of cohort studies to assess the mortality risk in stroke patients with and without anemia. Systematic searches were conducted in the PubMed, China National Knowledge Infrastructure, Web of Science and Wanfang databases to identify relevant studies from inception to November 2015. The estimated odds ratio with a 95% confidence interval was pooled. subgroup analyses and sensitivity analyses were also conducted. We used Begg’s funnel plot and Egger’s test to detect the potential publication bias. Thirteen cohort studies with a total of 19239 patients with stroke were included in this meta-analysis. The heterogeneity among studies was slight (I² = 59.0%, P = 0.031). The results from a random-effect model suggest that anemia is associated with an increased mortality risk in patients with stroke (adjusted odds ratio = 1.39, 95% confidence interval: 1.22–1.58, P < 0.001). The subgroup analyses are consistent with the total results. This meta-analysis of 13 cohort studies finds that anemia increases the mortality risk in patients with stroke. Future studies should perform longer follow-up to confirm this finding and explore its possible mechanism.

Estimated GFR and the Effect of Intensive Blood Pressure Lowering After Acute Intracerebral Hemorrhage

BACKGROUND

The kidney-brain interaction has been a topic of growing interest. Past studies of the effect of kidney function on intracerebral hemorrhage (ICH) outcomes have yielded inconsistent findings. Although the second, main phase of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2) suggests the effectiveness of early intensive blood pressure (BP) lowering in improving functional recovery after ICH, the balance of potential benefits and harms of this treatment in those with decreased kidney function remains uncertain.

STUDY DESIGN

Secondary analysis of INTERACT2, which randomly assigned patients with ICH with elevated systolic BP (SBP) to intensive (target SBP<140mmHg) or contemporaneous guideline-based (target SBP<180mmHg) BP management.

SETTING & PARTICIPANTS

2,823 patients from 144 clinical hospitals in 21 countries.

PREDICTORS

Admission estimated glomerular filtration rates (eGFRs) of patients were categorized into 3 groups based on the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation: normal or high, mildly decreased, and moderately to severely decreased (>90, 60-90, and <60mL/min/1.73m(2), respectively).

OUTCOMES

The effect of admission eGFR on the primary outcome of death or major disability at 90 days (defined as modified Rankin Scale scores of 3-6) was analyzed using a multivariable logistic regression model. Potential effect modification of intensive BP lowering treatment by admission eGFR was assessed by interaction terms.

RESULTS

Of 2,623 included participants, 912 (35%) and 280 (11%) had mildly and moderately/severely decreased eGFRs, respectively. Patients with moderately/severely decreased eGFRs had the greatest risk for death or major disability at 90 days (adjusted OR, 1.82; 95% CI, 1.28-2.61). Effects of early intensive BP lowering were consistent across different eGFRs (P=0.5 for homogeneity).

LIMITATIONS

Generalizability issues arising from a clinical trial population.

CONCLUSIONS

Decreased eGFR predicts poor outcome in acute ICH. Early intensive BP lowering provides similar treatment effects in patients with ICH with decreased eGFRs.

Individualizing pharmacotherapy in patients with renal impairment: the validity of the Modification of Diet in Renal Disease formula in specific patient populations with a glomerular filtration rate below 60 ml/min. A systematic review

Background

The Modification of Diet in Renal Disease (MDRD) formula is widely used in clinical practice to assess the correct drug dose. This formula is based on serum creatinine levels which might be influenced by chronic diseases itself or the effects of the chronic diseases. We conducted a systematic review to determine the validity of the MDRD formula in specific patient populations with renal impairment: elderly, hospitalized and obese patients, patients with cardiovascular disease, cancer, chronic respiratory diseases, diabetes mellitus, liver cirrhosis and human immunodeficiency virus.

Methods and Findings

We searched for articles in Pubmed published from January 1999 through January 2014. Selection criteria were (1) patients with a glomerular filtration rate (GFR) < 60 ml/min (/1.73m²), (2) MDRD formula compared with a gold standard and (3) statistical analysis focused on bias, precision and/or accuracy. Data extraction was done by the first author and checked by a second author. A bias of 20% or less, a precision of 30% or less and an accuracy expressed as P₃₀% of 80% or higher were indicators of the validity of the MDRD formula. In total we included 27 studies. The number of patients included ranged from 8 to 1831. The gold standard and measurement method used varied across the studies. For none of the specific patient populations the studies provided sufficient evidence of validity of the MDRD formula regarding the three parameters. For patients with diabetes mellitus and liver cirrhosis, hospitalized patients and elderly with moderate to severe renal impairment we concluded that the MDRD formula is not valid. Limitations of the review are the lack of considering the method of measuring serum creatinine levels and the type of gold standard used.

Conclusion

In several specific patient populations with renal impairment the use of the MDRD formula is not valid or has uncertain validity.

Anemia on admission predicts short- and long-term outcomes in patients with acute ischemic stroke

BACKGROUND

It is still debatable whether anemia predicts stroke outcome.

AIM

To describe the characteristics of patients with acute ischemic stroke (AIS) and anemia and identify whether hemoglobin status on admission is a prognostic factor of AIS outcome.

METHODS

All 2439 patients of the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) between January 2003 and June 2011 were selected. Demographics, risk factors, prestroke treatment, clinical, radiological and metabolic variables in patients with and without anemia according to the definition of the World Health Organization were compared. Functional disability and mortality were recorded up to 12 months from admission.

RESULTS

Anemic patients (17.5%) were older, had lower body mass index, higher rates of coronary artery disease (CAD), atrial fibrillation, diabetes mellitus and peripheral artery disease. Anemia was associated with more severe stroke manifestations, lower systolic and diastolic blood pressure measurements, worse estimated glomerular filtration rate and elevated C-reactive protein concentrations upon admission and with increased modified Rankin scores during the follow-up. Anemic patients had higher 7-day, 3-month and 12-month mortality, which was associated with hemoglobin status and other factors, including age, CAD, stroke severity, and baseline C-reactive levels. Hemoglobin levels were inversely associated with recurrent stroke and mortality throughout the 12-month follow-up.

CONCLUSION

Anemia is common among AIS patients and is associated with cardiovascular comorbidities. Low hemoglobin status independently predicts short and long-term mortality.

Renal Dysfunction in Stroke Patients: A Hospital-Based Cohort Study and Systematic Review

Background and purpose

Renal dysfunction (i.e. a reduced estimated glomerular filtration rate, eGFR) is commonly found in hospitalized stroke patients but its associations with Patients' characteristics and outcome require further investigation.

Methods

We linked clinical data from stroke patients enrolled between 2005 and 2008 into two prospective hospital registers with routine laboratory eGFR data. The eGFR was calculated using the Modification of Diet in Renal Disease method and renal dysfunction was defined as <60 ml/min/1·73 m2. In addition we systematically reviewed studies investigating the association between eGFR and outcome after stroke.

Results

Of 2520 patients who had an eGFR measured on admission hospital, 805 (32%) had renal dysfunction. On multivariate analysis, renal dysfunction was significantly less likely in those with a predicted good outcome (OR 0·27, 95% CI 0·21, 0·36) based on the well-validated six simple variable model. After adjustment for other predictive factors, stroke patients with renal dysfunction were more likely to die in hospital compared with those without (odds ratio 1·59, 95% confidence intervals 1·26, 2·00). Of the 31 studies involving 41 896 participants included in the systematic review, 18 studies found that low eGFR was an independent predictor of death and 6 reported a significant association with death and disability.

Conclusion

Our findings suggest that renal dysfunction on admission is common and associated with poor outcomes over the first year. Further work is required to establish to what extent these associations are causal and whether treating impaired renal function improves outcomes.

Association between ischemic stroke and iron-deficiency anemia: a population-based study

Background

Very little is known about the relationship between non-sickle cell anemia and stroke. The purpose of this study is to evaluate the association of iron-deficiency anemia (IDA) with stroke based on a nationwide coverage database in Taiwan.

Methods

The case-control study subjects were obtained from the Taiwanese Longitudinal Health Insurance Database 2000. We included 51,093 subjects with stroke as cases and randomly selected 153,279 controls (3 controls per case) in this study.Separate conditional logistic regression analyses were used to calculate the odds ratio (OR) for having been previously diagnosed with IDA between cases and controls.We further analyzed the association between stroke and IDA by stroke subtype.

Results

Results showed that 3,685 study subjects (1.81%) had been diagnosed with IDA prior to the index date; of those subjects, 1,268 (2.48%) were cases and 2,417 (1.58%) were controls (p<0.001). Conditional logistic regression shows that the OR of having previously received an IDA diagnosis among cases was 1.49 (95% CI: 1.39~1.60; p < 0.01) that of controls after adjusting for monthly income, geographic region, hypertension, diabetes, coronary heart disease, atrial fibrillation, heart failure, hyperlipidemia, tobacco use disorder, and alcohol abuse/alcohol dependency syndrome. Furthermore, the adjusted OR of prior IDA for cases with ischemic stroke was found to be 1.45 (95% CI: 1.34~1.58) compared to controls. However, we did not find any significant relationship between IDA and subarachnoid/intracerebral hemorrhage even adjusting for other confounding factors (OR=1.17, 95% CI=0.97~1.40).

Conclusion

There is a significant association between prior IDA and ischemic stroke.

Association of anemia with the risk of cardiovascular adverse events in overweight/obese patients

OBJECTIVE

Anemia is associated with increased cardiovascular risks. Obesity may cause anemia in several ways, for example, by low-grade inflammation and relative iron deficit. The outcomes associated with anemia in overweight/obese patients at high cardiovascular risk are however not known. Therefore, we investigated the cardiovascular prognosis in overweight/obese subjects with anemia.

METHODS

A total of 9,687 overweight/obese cardiovascular high-risk patients from the Sibutramine Cardiovascular OUTcomes trial were studied. Patients were stratified after baseline hemoglobin level and followed for the risks of primary event (comprising nonfatal myocardial infarction, nonfatal stroke, resuscitated cardiac arrest or cardiovascular death) and all-cause mortality. Risk estimates (hazard ratios (HR) with 95% confidence intervals (CI)) were calculated using Cox regression models.

RESULTS

Anemia was unadjusted associated with increased risk for the primary event, HR 1.73 (CI 1.37-2.18) and HR 2.02 (CI 1.34-3.06) for patients with mild or moderate-to-severe anemia, respectively, compared with patients without anemia. Adjusted for several confounders, anemia remained of prognostic importance. Increased risk of the primary events appeared to be driven by risk of cardiovascular death, adjusted HR 1.82 (CI 1.33-2.51) for mild anemia and adjusted HR 1.65 (CI 0.90-3.04) for moderate-to-severe anemia, and all-cause mortality, adjusted HR 1.50 (CI 1.17-1.93) for mild and adjusted HR 1.61 (CI 1.04-2.51) for moderate-to-severe anemia. While adding serum creatinine to the models, the increased risk of mild anemia was still a significant predictor for mortality (cardiovascular and all-cause), whereas moderate-to-severe anemia was not. For the primary events, anemia was no longer of independent prognostic importance when including serum creatinine.

CONCLUSION

Anemia is associated with an increased risk of long-term adverse cardiovascular events and deaths among overweight/obese cardiovascular high-risk patients. The increased risk appeared to be driven by the risk of cardiovascular death and all-cause mortality, and renal impairments seemed to have a role in the increased risk.

The low number of red blood cells is an important risk factor for all-cause mortality in the general population

Patients with advanced chronic kidney disease (CKD) show decreased hemoglobin levels. We aimed to verify the changes of red blood cell (RBC) number according to glomerular filtration rate (GFR) levels and its influence on the clinical outcome. With the data from routine health checkups of 114,496 adults, we grouped the subjects according to quartile levels of RBC number in each gender. Mortality data were from the National Statistical Office. RBC number was increased with decreasing GFR and/or the presence of a component of metabolic syndrome (MS) in subjects with GFR ≥ 50 ml/min/1.73 m². The estimated mean RBC number of subjects with GFR 89-50 ml/min/1.73 m² was higher compared to those with GFR ≥ 100 ml/min/1.73 m² by ANCOVA. In men, the death rate was the highest in the 1st quartile group (1Q) of RBC number (1.22%), followed by the 2nd quartile group (2Q, 0.42%), the 3rd quartile group (3Q, 0.39%), and the 4th quartile group (4Q, 0.29%) (p < 0.001). The hazard ratio (HR) of death in 2Q, 3Q and 4Q was 0.446, 0.580, and 0.440, respectively, compared to 1Q (p < 0.001). Among men in 1Q group, subjects with hemoglobin < 14.0 g/dL showed higher mortality rate than those with hemoglobin 14.0-14.9 g/dL or ≥ 15.0 g/dL (2.3% : 0.8% : 1.1%, respectively, p < 0.001). In conclusion, the RBC number was increased according to declines of GFR in the range of GFR ≥ 50 ml/min/1.73 m² and was an important risk factor for mortality.

The development of anemia is associated to poor prognosis in NKF/KDOQI stage 3 chronic kidney disease

Background

Anemia is a common condition in CKD that has been identified as a cardiovascular (CV) risk factor in end-stage renal disease, constituting a predictor of low survival. The aim of this study was to define the onset of anemia of renal origin and its association with the evolution of kidney disease and clinical outcomes in stage 3 CKD (CKD-3).

Methods

This epidemiological, prospective, multicenter, 3-year study included 439 CKD-3 patients. The origin of nephropathy and comorbidity (Charlson score: 3.2) were recorded. The clinical characteristics of patients that developed anemia according to EBPG guidelines were compared with those that did not, followed by multivariate logistic regression, Kaplan-Meier curves and ROC curves to investigate factors associated with the development of renal anemia.

Results

During the 36-month follow-up period, 50% reached CKD-4 or 5, and approximately 35% were diagnosed with anemia (85% of renal origin). The probability of developing renal anemia was 0.12, 0.20 and 0.25 at 1, 2 and 3 years, respectively. Patients that developed anemia were mainly men (72% anemic vs. 69% non-anemic). The mean age was 68 vs. 65.5 years and baseline proteinuria was 0.94 vs. 0.62 g/24h (anemic vs. non anemic, respectively). Baseline MDRD values were 36 vs. 40 mL/min and albumin 4.1 vs. 4.3 g/dL; reduction in MDRD was greater in those that developed anemia (6.8 vs. 1.6 mL/min/1.73 m²/3 years). These patients progressed earlier to CKD-4 or 5 (18 vs. 28 months), with a higher proportion of hospitalizations (31 vs. 16%), major CV events (16 vs. 7%), and higher mortality (10 vs. 6.6%) than those without anemia. Multivariate logistic regression indicated a significant association between baseline hemoglobin (OR=0.35; 95% CI: 0.24-0.28), glomerular filtration rate (OR=0.96; 95% CI: 0.93-0.99), female (OR=0.19; 95% CI: 0.10-0.40) and the development of renal anemia.

Conclusions

Renal anemia is associated with a more rapid evolution to CKD-4, and a higher risk of CV events and hospitalization in non-dialysis-dependent CKD patients. This suggests that special attention should be paid to anemic CKD-3 patients.

Renal anemia - risk factor for chronic kidney disease

The purpose of this research was to analyze the influence of anemia on renal function in patients with chronic kidney disease. Were monitored for 12 months 165 patients with chronic kidney disease, 96 patients had anemia and a control group of 69 patients had no anemia. A value of hemoglobin under 120 g/L in women and under 130 g/L in men on admission defined anemia. Anemia was associated with a more severe renal damage, a lower residual diuresis, especially in the presence of other risk factors such as diabetes, inflammation or secondary hyperparathyroidism, so early diagnosis and correction of anemia is important for prognosis and evolution of these patients.

A cohort study of patients with anemia on admission and fatality after acute ischemic stroke

Reduced blood hemoglobin levels may impair oxygen delivery to the brain and hinder neurological improvement. We prospectively registered consecutively hospitalized Chinese patients with acute ischemic stroke within 24 hours of symptom onset to investigate whether anemia on admission influences case fatality and functional outcome of acute ischemic stroke at 12 months. Anemia was defined as a blood hemoglobin level of < 120 g/L for women, and < 130 g/L for men. We also performed a meta-analysis of the current cohort and previously published studies. We included 1176 patients, of whom 351 patients (29.8%) had anemia. Age (odds ratio [OR]=1.02, 95% confidence interval [CI]: 1.01-1.03), history of hemorrhagic stroke (OR=3.34, 95% CI: 1.17-9.56), alcohol consumption (OR=0.59, 95% CI: 0.38-0.92), and estimated glomerular filtration rate < 60 mL/minute per 1.73 m(2) (OR=1.34, 95% CI: 1.00-1.80) were the independent predictors of anemia. After adjustment for potential confounders, anemia on admission was shown to be an independent predictor of death at discharge and at 12 months (OR=1.66, 95% CI, 1.08-2.56; OR=1.56, 95% CI, 1.05-2.31). A meta-analysis of six included studies involving 3810 participants confirmed that anemia on admission was an independent predictor of death at the end of follow-up (OR=1.67, 95% CI, 1.25-2.08). Further studies are required to confirm these findings.