ABSTRACT
OBJECTIVE: Our aim was to investigate the relationship between impaired peripheral arterial circulation as measured by ankle-brachial index (ABI) and restless legs syndrome (RLS) in the general population. METHODS: Data are derived from three independent, German population-based, prospective studies: the control sample of BiDirect (N = 966), the second follow-up of SHIP (N = 2333), and a subsample of SHIP-Trend (N = 1269). RLS was assessed with questions based on the RLS minimal criteria. ABI was measured with an automated method in BiDirect and with Doppler ultrasound in both SHIP studies. An ABI score below 0.9 was indicative of peripheral arterial disease (PAD). Co-morbidities, medications and behavioural factors were self-reported. Additional measurements included body mass index and haemoglobin from blood serum. For BiDirect, a follow-up with identical methodology was performed after a median of 2.5 years. RESULTS: In cross-sectional analyses, decreased ABI was not significantly associated with RLS as outcome in multivariable logistic regression models adjusted for several potential confounders (BiDirect: odds ratio (OR) = 1.07 for a -0.1 change in ABI, 95% confidence interval (CI): 0.81-1.42, p = 0.62; SHIP-2: OR = 0.99, CI: 0.85-1.16, p = 0.94; SHIP-Trend: OR = 0.99, CI: 0.87-1.13, p = 0.88). Similar non-significant results were achieved using PAD (instead of ABI) as an independent variable. In BiDirect, baseline ABI was not a significant predictor of incident RLS in longitudinal analysis (OR = 0.77, CI: 0.53-1.12, p = 0.17). CONCLUSION: Results from three independent studies suggest that reduced ABI is not a risk factor for RLS in the general population.
Subject(s)
Ankle Brachial Index , Peripheral Arterial Disease/physiopathology , Regional Blood Flow , Restless Legs Syndrome/physiopathology , Body Mass Index , Comorbidity , Cross-Sectional Studies , Female , Follow-Up Studies , Germany , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Peripheral Arterial Disease/diagnostic imaging , Prospective Studies , Restless Legs Syndrome/diagnostic imaging , Risk Factors , Severity of Illness Index , Ultrasonography, DopplerABSTRACT
Although anemia is a known risk factor of mortality in several patient populations, no prospective study to date has demonstrated association between anemia and mortality in kidney-transplanted patients. In our prospective cohort study (TransQol-HU Study), we tested the hypothesis that anemia is associated with mortality and graft failure (return to dialysis) in transplanted patients. Data from 938 transplanted patients, followed at a single outpatient transplant center, were analyzed. Sociodemographic parameters, laboratory data, medical history and information on comorbidity were collected at baseline. Data on 4-year outcome (graft failure, mortality or combination of both) were collected prospectively from the patients' charts. Both mortality and graft failure rate during the 4-year follow-up was significantly higher in patients who were anemic at baseline (for anemic vs nonanemic patients, respectively: mortality 18% vs. 10%; p < 0.001; graft failure 17% vs 6%; p < 0.001). In multivariate Cox proportional hazard models the presence of anemia significantly predicted mortality (HR = 1.690; 95% CI: 1.115-2.560) and also graft failure (HR = 2.465; 95% CI: 1.485-4.090) after adjustment for several covariables. Anemia, which is a treatable complication, is significantly and independently associated with mortality and graft failure in kidney-transplanted patients.
