Prevalence of vitamin B(12) depletion and deficiency in Liechtenstein.

OBJECTIVE: Data about vitamin B(12) (B(12)) deficiency in the general population are scarce. The present study was performed to determine the prevalence of B(12) deficiency in the general population of the Principality of Liechtenstein, as well as to identify sub-populations potentially at high risk. DESIGN: Retrospective study. SETTING: Ambulatory setting, population of the Principality of Liechtenstein. SUBJECTS: Seven thousand four hundred and twenty-four patients seeking medical attention whose serum samples were referred for routine work-up in an ambulatory setting were consecutively enrolled. Serum total B(12) was determined in all patients in this cohort. In addition, for a subgroup of 1328 patients, serum holotranscobalamin was also measured. Prevalence of B(12) deficiency was calculated. Further, multivariate logistical regression models were applied to identify covariates independently associated with B(12) deficiency and depletion. RESULTS: Nearly 8% of the general population was suffering from either B(12) depletion or deficiency. The ratio between B(12) depletion and deficiency was 2:1 for all age ranges. Pathological changes were detected predominantly in older people. Female gender was a significant predictor of B(12) depletion. In the cohort, nearly 40% exhibited either depletion or deficiency of B(12). CONCLUSIONS: B(12) depletion and deficiency are common in Liechtenstein, a Central European country. The measurement of biochemical markers represents a cost-efficient and valid assessment of the B(12) state. When a deficiency of B(12) is diagnosed at an early stage, many cases can be treated or prevented, with beneficial effects on individual outcomes and subsequent potential reductions in health-care costs.

Stability of hematological analytes depends on the hematology analyser used: a stability study with Bayer Advia 120, Beckman Coulter LH 750 and Sysmex XE 2100.

AIM: With the availability of newer hematology analysers, novel measurement techniques are being introduced into daily routine. As analyte stability may differ according to the employed measurement technique, the aim of this study was to assess the stability of hematologic analytes on different hematology analysers. METHODS: We investigated the effect of storage time and storage temperature on sample stability on three newer analytical systems (Advia 120, Bayer Diagnostics; XE 2100, Sysmex and LH 750, Beckman Coulter). Samples were obtained from 64 healthy volunteers and stored at room temperature as well at 4-8 degrees C in order to conduct analysis at different timepoints up to 72 h after blood was drawn. Sample stability was assessed by the graphical truncated normal sequential test. A parameter was considered stable, when its average change was smaller than one coefficient of variation CV (%) of the assessed method, allowing a 5% risk of error. RESULTS: Red blood cell counts, mean corpuscular hemoglobin (MCH) and hemoglobin are least affected by storage temperature and showed stability for at least 48 h, depending on analyser utilized. While reticulocytes, mean corpuscular volume (MCV), hematocrit and leukocyte counts were more stable at 4-8 degrees C, thrombocytes exhibited a better stability at RT. The white blood cell (WBC) subpopulations changed over time with a decrease in eosinophils and lymphocytes and an increase in neutrophils at 4-8 degrees C. Further, the stability pattern of WBC subpopulations was significantly different among the 3 investigated analysers with some analytes only displaying a stability of 4 h. CONCLUSIONS: Analyte stability of hematological parameters varies not only according to the investigated parameter but also according to storage temperature and the employed measurement system. Depending on the analyte sample stability differences among the different analytical systems are considerable.

Prevalence of decreased glomerular filtration rate in patients seeking non-nephrological medical care--an evaluation using IDMS-traceable creatinine based MDRD as well as Mayo Clinic quadratic equation estimates.

BACKGROUND: Data on the prevalence of decreased glomerular filtration rate in Europe are limited. Most of the available studies did not employ laboratory methods providing creatinine concentrations traceable to the reference method, i.e. isotope dilution mass spectrometry (IDMS). METHODS: We therefore conducted a cross-sectional study in the principality of Liechtenstein consecutively enrolling adult patients seeking non-nephrological medical care from whom serum samples were referred for renal function assessment. All measurements were done in one central laboratory. The estimated glomerular filtration rate (eGFR) was calculated based on the determination of IDMS-traceable creatinine by a kinetic Jaffe method (Roche Diagnostics, Switzerland) by means of the MDRD and Mayo Clinic quadratic equations. We further estimated the incidence of end stage renal disease during the next 5 years. RESULTS: For 43% (n=9378) of the entire population>or=25 years renal function assessment was available. An eGFR indicating chronic kidney disease (CKD) stages 3-5 was found in 4.93% when using the MDRD equation and in 3.98 % when using the Mayo Clinic quadratic equation. The two equations had a very good agreement in classifying patients to have an eGFR consistent with CKD stages 3-5 (Cohen's kappa 0.887). Further calculations suggested that among patients aged 80 or younger, annually 42 per 100,000 are going to develop an eGFR<15 ml/min/1.73 m2 over the next 5 years. CONCLUSIONS: 4-5% of patients seeking non-nephrological medical advice have an eGFR consistent with CKD stages 3-5, and a considerable number of subjects is expected to develop end stage renal disease over a 5 year period. In order to obtain comparable kidney function estimates among different institutions it is not only important to use standardized methods to measure creatinine but rather to employ standardized methods to calculate a GFR estimate.