Association between socioeconomic position and cystatin C in the Heinz Nixdorf Recall Study.

Social inequalities in health and disease are well studied. Less information is available on inequalities in biomarker levels indicating subclinical stages of disease such as cystatin C, an early diagnostic marker of renal dysfunction and predictor for cardiovascular disease. We evaluated the relationship between cystatin C, socioeconomic position (SEP) and established cardiovascular risk factors in a population-based study. In 4475 men and women aged 45-75 years participating in the baseline examination of the Heinz Nixdorf Recall Study cystatin C was measured from serum samples with a nephelometric assay. SEP was assessed by education and household income. Linear regression models were used to analyse the association between SEP and cystatin C as well as the impact of cardiovascular risk factors (i.e., body mass index, blood pressure, blood glucose, diabetes mellitus, blood lipids, C-reactive protein, smoking) on this association. After adjustment for age and sex cystatin C decreased by 0.019 mg/l (95% confidence interval (CI) - 0.030 to - 0.008) per five years of education. While using a categorical education variable cystatin C presented 0.039 mg/l (95% CI 0.017-0.061) higher in men and women in the lowest educational category (≤ 10 years of education) compared to the highest category (≥ 18 years). Concerning income, cystatin C decreased by 0.014 mg/l (95% CI - 0.021 to - 0.006) per 1000 € after adjustment for age and sex. For men and women in the lowest income quartile cystatin C was 0.024 mg/l (95% CI 0.009-0.038) higher compared to the highest income quartile. After adjusting for established cardiovascular risk factors the observed associations were substantially diminished. Social inequalities seem to play a role in subclinical stages of renal dysfunction, which are also related to development of cardiovascular disease. Adjustment for traditional cardiovascular risk factors showed that these risk factors largely explain the association between SEP and cystatin C.

Subtyping of Primary Aldosteronism in the AVIS-2 Study: Assessment of Selectivity and Lateralization.

CONTEXT: Adrenal venous sampling (AVS) is the key test for subtyping primary aldosteronism (PA), but its interpretation varies widely across referral centers and this can adversely affect the management of PA patients. OBJECTIVES: To investigate in a real-life study the rate of bilateral success and identification of unilateral aldosteronism and their impact on blood pressure outcomes in PA subtyped by AVS. DESIGN AND SETTINGS: In a retrospective analysis of the largest international registry of individual AVS data (AVIS-2 study), we investigated how different cut-off values of the selectivity index (SI) and lateralization index (LI) affected rate of bilateral success, identification of unilateral aldosteronism, and blood pressure outcomes. RESULTS: AVIS-2 recruited 1625 individual AVS studies performed between 2000 and 2015 in 19 tertiary referral centers. Under unstimulated conditions, the rate of biochemically confirmed bilateral AVS success progressively decreased with increasing SI cut-offs; furthermore, with currently used LI cut-offs, the rate of identified unilateral PA leading to adrenalectomy was as low as <25%. A within-patient pairwise comparison of 402 AVS performed both under unstimulated and cosyntropin-stimulated conditions showed that cosyntropin increased the confirmed rate of bilateral selectivity for SI cut-offs ≥ 2.0, but reduced lateralization rates (P < 0.001). Post-adrenalectomy outcomes were not improved by use of cosyntropin or more restrictive diagnostic criteria. CONCLUSION: Commonly used SI and LI cut-offs are associated with disappointingly low rates of biochemically defined AVS success and identified unilateral PA. Evidence-based protocols entailing less restrictive interpretative cut-offs might optimize the clinical use of this costly and invasive test. (J Clin Endocrinol Metab XX: 0-0, 2020).

Costs of dialysis--a regional population-based analysis.

BACKGROUND: Population-based estimates of costs of renal replacement therapy are scarce in the literature. The aim of our study was to calculate the costs of long-term dialysis in 2006 on the basis of patient-specific data from a well-defined population in a region in western Germany (n = 310,757). METHODS: Cost estimation was performed from the perspective of the statutory health insurance. All dialysis patients from the study region (n = 344, 54% male, mean age (+/-SD) 69 +/- 13 years, 42% diabetic) were assessed for the costs of the dialysis procedures, dialysis-related hospital admissions, outpatient contacts outside of our dialysis center, dialysis-related medication, patient transportation and related costs (e.g. reimbursement fees on the basis of the German diagnosis-related group system, price scales). We estimated the cumulative cost per patient year in 2006 (in Euros), along with the 10th and 90th percentiles and the 95% confidence intervals (CI) by using bootstrapping procedures. RESULTS: The mean total dialysis-related cost in 2006 was 54,777 Euros (95% CI, 51,445-65,705) per patient year. The largest part of the costs (55%) was caused by the dialysis procedures, followed by the costs of medication (22%), hospitalization (14%) and transportation (8%). The total cost increased significantly with increasing age. No significant association was found between total cost and sex, dialysis strategy, end-stage renal disease duration and diabetes. CONCLUSIONS: We present for the first time a cost estimation of dialysis in Germany on the basis of patient-level data in a population-based sample. Except age, patient characteristics were not significantly associated with costs. The largest part of the costs was caused by the dialysis procedures themselves; however, other dialysis-specific health care utilization also strongly contributed to the total cost.