The role of functional vitamin D deficiency and low vitamin D reservoirs in relation to cardiovascular health and mortality.

OBJECTIVES: The role of vitamin D deficiency in cardiovascular disease (CVD) is controversial. Inherent biological and analytical limitations compromise the specificity of widely used 25-hydroxyvitamin D [25(OH)D] cut-offs. Simultaneous determination of 25(OH)D and 24,25-dihydroxyvitamin D [24,25(OH)2D] permits a functional assessment of vitamin D metabolism. The present study compared the associations of functional vitamin D deficiency and low vitamin D reservoirs with CVD mortality and CVD burden. METHODS: 25(OH)D, 24,25(OH)2D, the degree of coronary obstruction on angiography, high-sensitive cardiac troponin T (hs-cTnT), N-terminal brain natriuretic peptide (NT-proBNP), and 10-year CVD mortality were obtained from 2,456 participants of the LURIC (Ludwigshafen Risk and Cardiovascular Health) study. RESULTS: Neither low 25(OH)D concentrations nor functional vitamin D deficiency were associated with the number of atherosclerotic coronary arteries or the degree of coronary obstruction. Over a median follow-up of 9.9 years, 454 participants died (23.6 %) due to CVD. CVD mortality was doubled in individuals with 25(OH)D concentrations below the widely used cut-off for deficiency of <50 nmol/L [20 ng/mL] (21.6 vs. 11.5 %). In individuals with and without functional vitamin D deficiency, CVD mortality was 25.0 and 16.7 %, respectively. NT-proBNP and heart failure prevalence were also higher in vitamin D deficient individuals. CONCLUSIONS: Vitamin D deficient individuals have markedly higher CVD mortality, but only marginally higher hs-cTnT concentrations. A higher prevalence of heart failure and higher NT-proBNP concentrations suggest a link between vitamin D deficiency and cardiac function. The traditional and metabolic assessment of vitamin D status showed comparable associations for the different parameters of cardiac health.

Classification of Vitamin D Status Based on Vitamin D Metabolism: A Randomized Controlled Trial in Hypertensive Patients.

Circulating 25-hydroxyvitamin D (25(OH)D) is the generally accepted indicator of vitamin D status. Since hydroxylation of 25(OH)D to 24-25-dihydroxyvitamin D (24,25(OH)2D) is the first step of its catabolism, it has been suggested that a low 24,25(OH)D level and a low vitamin D metabolite ratio (VMR), i.e., 24,25(OH)2D divided by 25(OH)D, may indicate high vitamin D requirements and provide additional diagnostic information beyond serum 25(OH)D. We, therefore, evaluated whether the classification of "functional vitamin D deficiency", i.e., 25(OH)D below 50 nmol/L, 24,25(OH)2D below 3 nmol/L and a VMR of less than 4%, identifies individuals who benefit from vitamin D supplementation. In participants of the Styrian Vitamin D Hypertension trial, a randomized controlled trial (RCT) in 200 hypertensive patients with serum 25(OH)D below 75 nmol/L, who received either 2.800 international units of vitamin D per day or placebo over 8 weeks, 51 participants had functional vitamin D deficiency. In these individuals, there was no treatment effect of vitamin D supplementation on various parameters of bone metabolism and cardiovascular risk except for a significant effect on parathyroid hormone (PTH) and expected changes in vitamin D metabolites. In conclusion, a low vitamin D metabolite profile did not identify individuals who significantly benefit from vitamin D supplementation with regard to bone markers and cardiovascular risk factors. The clinical significance of functional vitamin D deficiency requires further evaluation in large vitamin D RCTs.

Functional Assessment of Vitamin D Status by a Novel Metabolic Approach: The Low Vitamin D Profile Concept.

BACKGROUND: Determining serum 25-hydroxyvitamin D [25(OH)D], 24,25-dihydroxyvitamin D [24,25(OH)2D] and the vitamin D metabolite ratio (VMR) allows the identification of individuals with a low vitamin D metabolite profile. Here, we evaluated if such a functional approach provides superior diagnostic information to serum 25(OH)D alone. METHODS: 25(OH)D, 24,25(OH)2D, and the VMR were determined in participants of the DESIRE (Desirable Vitamin D Concentrations, n = 2010) and the LURIC (Ludwigshafen Risk and Cardiovascular Health, n = 2456) studies. A low vitamin D metabolite profile (vitamin D insufficiency) was defined by a 24,25(OH)2D concentration <1.2 ng/mL (<3 nmol/L) and a VMR <4%. Parathyroid hormone (PTH) and bone turnover markers were measured in both cohorts, whereas 10-year mortality data was recorded in LURIC only. RESULTS: The median age in DESIRE and LURIC was 43.3 and 63.8 years, respectively. Median 25(OH)D concentrations were 27.2 ng/mL (68.0 nmol/L) and 15.5 ng/mL (38.8 nmol/L), respectively. Serum 25(OH)D deficiency, defined as <20.2 ng/mL (<50 nmol/L), was present in 483 (24.0%) and 1701 (69.3%) participants of DESIRE and LURIC, respectively. In contrast, only 77 (3.8%) and 521 (21.2%) participants had a low vitamin D metabolite profile. Regardless of the serum 25(OH)D concentration, a low vitamin D metabolite profile was associated with a significantly higher PTH, accelerated bone metabolism, and higher all-cause mortality than an unremarkable vitamin D metabolite profile. CONCLUSIONS: The personalized assessment of vitamin D status using a functional approach better identifies patients with accelerated bone metabolism and increased mortality than the use of a fixed 25(OH)D cutoff of 20 ng/mL (50 nmol/L).

Associations of Parameters of the Tryptophan-Kynurenine Pathway with Cardiovascular Risk Factors in Hypertensive Patients.

Accumulating evidence suggests an association of the tryptophan−kynurenine (TRP-KYN) pathway with atherosclerosis and cardiovascular risk factors. In this cross-sectional analysis we investigated whether TRP-KYN pathway parameters are associated with 24 h blood pressure (BP) and other risk factors in patients with arterial hypertension from a tertiary care centre. In 490 participants, we found no significant and independent association of 24 h systolic and diastolic BP with parameters of the TRP-KYN pathway. However, linear regression analyses of HDL as dependent and TRP, KYN and quinolinic acid (QUIN) as explanatory variables adjusted for BMI and sex showed significant associations. These were found for KYN, BMI and sex (unstandardised beta coefficient −0.182, standard error 0.052, p < 0.001; −0.313 (0.078), p < 0.001; −0.180 (0.024), p < 0.001, respectively) as well as for QUIN, BMI and sex (−0.157 (0.038), p < 0.001; −0.321 (0.079), p < 0.001; −0.193 (0.024), p < 0.001, respectively). Smokers had significantly lower levels of KYN (2.36 µmol/L, IQR 2.01−2.98, versus 2.71 µmol/L, IQR 2.31−3.27, p < 0.001), QUIN (384 nmol/L, IQR 303−448, versus 451 nmol/L, IQR 369−575, p < 0.001) and KYN/TRP ratio (38.2, IQR 33.7−43.2, versus 43.1, IQR 37.5−50.9, p < 0.001) compared to non-smokers. We demonstrated that TRP/KYN pathway metabolites are associated with some cardiovascular risk factors, warranting further studies to elucidate the diagnostic and therapeutic potential of the TRP-KYN pathway for cardiovascular diseases.

Diagnostic Workup of Microcytic Anemia: An Evaluation of Underuse or Misuse of Laboratory Testing in a Hospital Setting Using the AlinIQ System.

CONTEXT.­: Underuse of laboratory testing has been previously investigated in preselected populations, such as documented malpractice claims. However, these numbers might not reflect real-life situations. OBJECTIVE.­: To evaluate the underuse and misuse of laboratory follow-up testing in a real-life hospital patient population with microcytic anemia, using laboratory results ordered during routine patient care. DESIGN.­: From all patients in whom a microcytic anemia was detected during routine diagnostics in 2018, all available laboratory data were collected and screened for appropriateness of diagnostic workup of iron deficiency and thalassemia. Subgroup analysis was performed for patient groups with mean corpuscular volume values 75 to 79 µm3 (group 1), 65 to 74 µm3 (group 2), and <65 µm3 (group 3). RESULTS.­: A total of 2244 patients with microcytic anemia were identified. Follow-up testing for iron deficiency was not performed in 761 cases (34%). For inconclusive ferritin levels due to elevated C-reactive protein results (n = 336), reticulocyte hemoglobin content or soluble transferrin receptor levels were missing in 86 cases (26%). In patients with suspected thalassemia (n = 127), follow-up testing for hemoglobin variants was not performed in 70 cases (55%). Subgroup analysis showed that the frequency of underuse of iron status as well as thalassemia/hemoglobinopathy testing decreased from group 1 to group 3. When considering relevant preexisting anemia diagnoses, laboratory tests were underused in 904 cases (40.3%). CONCLUSIONS.­: Because 40% (n = 904) of the patients with microcytic anemia were potentially not followed up correctly, laboratory specialists are advised to act by implementing demand management strategies in collaboration with clinicians to overcome underuse of laboratory tests and to improve patient safety.

Acidification of 24-hour urine in urolithiasis risk testing: An obsolete relic?

BACKGROUND: Recommendations on the optimal preservation of 24 h urine for the metabolic work-up in urolithiasis patients are very heterogeneous. In case two such tests with different storage condition recommendations are being analysed, multiple collections would be needed, challenging especially elderly and very young patients. We therefore aimed to evaluate the stability of urine constituents under different storage conditions. MATERIAL AND METHODS: We collected urine samples from ten healthy volunteers and prepared aliquots to be stored either at room temperature or 4 °C. Some aliquots were preserved using hydrochloric acid prior to storage, some thereafter, some using the BD Urine preservation tube and some were not preserved at all. Storage duration was 0, 24, 48 or 72 h. In all samples calcium, magnesium, phosphorus, creatinine, oxalate, citrate and uric acid were measured and compared to the according reference sample. RESULTS: We could not find any significant deviation for any of the analytes and preanalytical treatment conditions compared to the associated reference sample. CONCLUSION: Preservation of 24 h urine for the metabolic evaluation in stone formers might not be necessary for sample storage up to 72 h.

Effects of Vitamin D Supplementation on 24-Hour Blood Pressure in Patients with Low 25-Hydroxyvitamin D Levels: A Randomized Controlled Trial.

Accumulating evidence suggests that potential cardiovascular benefits of vitamin D supplementation may be restricted to individuals with very low 25-hydroxyvitamin D (25(OH)D) concentrations; the effect of vitamin D on blood pressure (BP) remains unclear. We addressed this issue in a post hoc analysis of the double-blind, randomized, placebo-controlled Styrian Vitamin D Hypertension Trial (2011−2014) with 200 hypertensive patients with 25(OH)D levels <30 ng/mL. We evaluated whether 2800 IU of vitamin D3/day or placebo (1:1) for 8 weeks affects 24-hour systolic ambulatory BP in patients with 25(OH)D concentrations <20 ng/mL, <16 ng/mL, and <12 ng/mL and whether achieved 25(OH)D concentrations were associated with BP measures. Taking into account correction for multiple testing, p values < 0.0026 were considered significant. No significant treatment effects on 24-hour BP were observed when different baseline 25(OH)D thresholds were used (all p-values > 0.30). However, there was a marginally significant trend towards an inverse association between the achieved 25(OH)D level with 24-hour systolic BP (−0.196 per ng/mL 25(OH)D, 95% CI (−0.325 to −0.067); p = 0.003). In conclusion, we could not document the antihypertensive effects of vitamin D in vitamin D-deficient individuals, but the association between achieved 25(OH)D concentrations and BP warrants further investigations on cardiovascular benefits of vitamin D in severe vitamin D deficiency.

Randomized trial of vitamin D versus placebo supplementation on markers of systemic inflammation in hypertensive patients.

BACKGROUND AND AIMS: Animal and cell models indicated that vitamin D modulates inflammatory activity, which is considered relevant in the pathogenesis of arterial hypertension and cardiovascular diseases. We therefore aimed to investigate the effect of vitamin D supplementation on systemic markers of inflammation in a cohort of hypertensive patients. METHODS AND RESULTS: The Styrian Vitamin D Hypertension Trial is a single-centre, double-blind, placebo-controlled study conducted from 2011 to 2014 in Austria. We enrolled 200 study participants with arterial hypertension and 25-hydroxy-vitamin-D (25(OH)D) concentration below 30 ng/mL. Study participants were randomized to receive either 2800 IU of vitamin D3 per day or placebo for 8 weeks. The present investigation is a post-hoc analysis using analysis of co-variance (ANCOVA). Outcome measures were biomarkers of inflammation including CRP, leukocytes including subtypes and leukocyte-to-lymphocyte ratio, leucine and kynurenic acid. A total of 187 participants (mean age 60.1 ± 11.3years; 47% women; mean baseline 25(OH)D 21.1 ± 5.6 ng/mL) completed the trial. ANCOVA revealed a mean treatment effect for none of the respective outcomes and no significant results were detected in various subgroup analyses. CONCLUSION: Vitamin D3 supplementation in hypertensive patients with insufficient 25(OH)D concentrations has no significant effect on lowering markers of systemic inflammation. Further studies investigating the effect of vitamin D on other inflammatory pathways and in populations with severe vitamin D deficiency and a significant inflammatory burden are required. REGISTRATION: ClinicalTrials.gov Identifier: NCT02136771; EudraCT No. 2009-018,125-70. Start Date: 2011-04-06.

Laboratory Demand Management Strategies-An Overview.

Inappropriate laboratory test selection in the form of overutilization as well as underutilization frequently occurs despite available guidelines. There is broad approval among laboratory specialists as well as clinicians that demand management strategies are useful tools to avoid this issue. Most of these tools are based on automated algorithms or other types of machine learning. This review summarizes the available demand management strategies that may be adopted to local settings. We believe that artificial intelligence may help to further improve these available tools.

Associations of Serum Cortisol with Cardiovascular Risk and Mortality in Patients Referred to Coronary Angiography.

CONTEXT: Serum cortisol may be associated with cardiovascular risk factors and mortality in patients undergoing coronary angiography, but previous data on this topic are limited and controversial. OBJECTIVE: We evaluated whether morning serum cortisol is associated with cardiovascular risk factors, lymphocyte subtypes, and mortality. METHODS: This is a prospective cohort study performed at a tertiary care centre in south-west Germany between 1997 and 2000. We included 3052 study participants who underwent coronary angiography. The primary outcome measures were cardiovascular risk factors, lymphocyte subtypes, and all-cause and cardiovascular mortality. RESULTS: Serum cortisol was associated with an adverse cardiovascular risk profile, but there was no significant association with coronary artery disease or acute coronary syndrome. In a subsample of 2107 participants, serum cortisol was positively associated with certain lymphocyte subsets, including CD16+CD56+ (natural killer) cells (P < 0.001). Comparing the fourth versus the first serum cortisol quartile, the crude Cox proportional hazard ratios (with 95% CIs) were 1.22 (1.00-1.47) for all-cause and 1.32 (1.04-1.67) for cardiovascular mortality, respectively. After adjustments for various cardiovascular risk factors, these associations were attenuated to 0.93 (0.76-1.14) for all-cause, and 0.97 (0.76-1.25) for cardiovascular mortality, respectively. CONCLUSIONS: Despite significant associations with classic cardiovascular risk factors and natural killer cells, serum cortisol was not a significant and independent predictor of mortality in patients referred to coronary angiography. These findings might reflect that adverse cardiovascular effects of cortisol could be counterbalanced by some cardiovascular protective actions.

NO Synthesis Markers are Not Significantly Associated with Blood Pressure and Endothelial Dysfunction in Patients with Arterial Hypertension: A Cross-Sectional Study.

Nitric oxide (NO) synthesis markers, comprising L-homoarginine, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), are significantly associated with cardiovascular events and mortality. Being involved in NO pathways, they may be of high importance regulating vascular tone and arterial hypertension, but data on this topic are sparse and controversial. In this study, we evaluated whether these NO synthesis markers are associated with blood pressure values and pulse wave velocity (PWV). This analysis was based on the data of the Styrian Vitamin D Hypertension Trial, which included adults with arterial hypertension. We analyzed correlations of NO synthesis markers with 24 h ambulatory blood pressure values and PWV (primary outcomes), as well as with anthropometric and laboratory data. A total of 509 patients were included in the present analysis. The mean age was 61.2 ± 10.5 years, mean PWV was 8.6 ± 2.4 m/s, mean 24 h systolic blood pressure was 127.5 ± 13.8 mmHg and mean 24 h diastolic blood pressure was 76.4 ± 9.5 mmHg. In bivariate analyses, there was a significant positive correlation between homoarginine and 24 h diastolic blood pressure (r = 0.1; p = 0.02), which was revealed to be no longer significant after adjustment for age, gender and glomerular filtration rate (GFR) in multivariate regression analysis. No other significant correlations of any NO synthesis markers with blood pressure or PWV were observed. In line with previous studies, there were inverse associations between homoarginine and age and between ADMA or SDMA and GFR (p < 0.05 for all). This study did not reveal a significant association between homoarginine, ADMA or SDMA and blood pressure or PWV in hypertensive adults. These results suggested that the associations of these parameters with adverse outcome may not be mediated by hypertension and/or endothelial dysfunction.

Associations of Thyroid Hormones and Resting Heart Rate in Patients Referred to Coronary Angiography.

Resting heart rate (RHR) is associated with increased risk of cardiovascular morbidity and mortality. Thyroid hormones exert several effects on the cardiovascular system, but the relation between thyroid function and RHR remains to be further established. We evaluated whether measures of thyroid hormone status are associated with RHR in patients referred to coronary angiography. Thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxin (FT4), and RHR were determined in 2795 participants of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study. Median (25th to 75th percentile) serum concentrations were 1.25 (0.76-1.92) mU/l for TSH, 4.8 (4.2-5.3) pmol/l for FT3 and 17.1 (15.4-19.0) pmol/l for FT4, and mean (±standard deviation) RHR was 68.8 (±11.7) beats/min. Comparing the highest versus the lowest quartile, RHR (beats/min) was significantly higher in the fourth FT4 quartile [3.48, 95% confidence interval (CI): 2.23-4.73; p <0.001] and in the fourth FT3 quartile (2.30, 95% CI: 1.06-3.55; p <0.001), but there was no significant difference for TSH quartiles. In multiple linear regression analyses adjusting for various potential confounders, FT3 and FT4 were significant predictors of RHR (p <0.001 for both). In subgroups restricted to TSH, FT3, and FT4 values within the reference range, both FT3 and FT4 remained significant predictors of RHR (p <0.001 for all). In conclusion, in patients referred to coronary angiography, FT3 and FT4 but not TSH were positively associated with RHR. The relationship between free thyroid hormones and RHR warrants further investigations regarding its diagnostic and therapeutic implications.

Errors within the total laboratory testing process, from test selection to medical decision-making - A review of causes, consequences, surveillance and solutions.

Laboratory analyses are crucial for diagnosis, follow-up and treatment decisions. Since mistakes in every step of the total testing process may potentially affect patient safety, a broad knowledge and systematic assessment of laboratory errors is essential for future improvement. In this review, we aim to discuss the types and frequencies of potential errors in the total testing process, quality management options, as well as tentative solutions for improvement. Unlike most currently available reviews on this topic, we also include errors in test-selection, reporting and interpretation/action of test results. We believe that laboratory specialists will need to refocus on many process steps belonging to the extra-analytical phases, intensifying collaborations with clinicians and supporting test selection and interpretation. This would hopefully lead to substantial improvements in these activities, but may also bring more value to the role of laboratory specialists within the health care setting.

Reducing the probability of falsely elevated HbA1c results in diabetic patients by applying automated and educative HbA1c re-testing intervals.

INTRODUCTION: Too frequent HbA1c measurements may lead to unnecessary treatment modifications of diabetic patients. The aim of this study was to estimate the percentage of falsely elevated HbA1c results in two hospitals, Landeskrankenhaus/Uniklinikum Salzburg (LKH) and Landesklinik St. Veit (STV), as well as to retrospectively investigate the effect of an automated and an educative 60-day re-testing interval (RTI). METHODS: The amount of estimated falsely elevated results (eFER), based on odds calculated using the baseline and the follow-up values and the time between these measurements, the number of HbA1c re-testings within 60 days as well as the overall number of ordered and performed HbA1c analyses were calculated. In LKH, an automated algorithm cancelling inappropriate HbA1c testing was applied, and in STV, educational actions were taken. RESULTS: Before RTI-implementation, eFER were 0.9% and 2.1% and within-60-days-re-testing were 15.0% and 7.4% of cases in LKH and STV, respectively. After RTI-implementation, these numbers decreased to 0.2% (p < .001) and 1.8% (p = .869) and within-60-days-re-testing decreased to 1.1% (p < .001) and 3.6% (p = .003) in LKH and STV, respectively. Median monthly HbA1c measurements decreased by 15.8% (p < .001) and 21.1% (p = .002) in LKH and STV, respectively. CONCLUSION: Both the educational and the automated 60-day-RTI were proven to be efficient in reducing overall HbA1c measurements, re-testing within 60 days and eFER.

The clinically effective use of cardiac markers by restructuring laboratory profiles at Cardiology wards.

Background: Laboratory overutilization is associated with diagnostic error and potential patient risk. We applied a demand management strategy in collaboration with the local Department of Cardiology to reduce the cardiac markers high-sensitive troponin T (hsTropT) and N-terminal pro brain natriuretic peptide (NTproBNP) in laboratory ordering profiles (LOPs). The present study aimed to retrospectively evaluate the implemented strategies. Methods: Strategies included educational measures and evidence-guided, active test de-selection from all cardiology ward LOPs, and/or permanent removal from LOPs. Tests remained available at all times. We evaluated overutilization by reductions in monthly orders, and assessed differences in 30-day all-cause readmission rate and length of patients' hospital stay. Results: Overall, we observed a mean reduction of 66.1% ± 7.6% (n = 277 ± 31) in hsTropT tests. Educational measures effectively reduced NTproBNP orders by 52.8% ± 17.7% (n = 60 ± 20). Permanent removal of tests from LOPs additionally decreased orders to a final extent of 75.8% ± 8.0% (n = 322 ± 31) in NTproBNP tests. The 30-day readmission rate and overall length of hospital stay did not increase. Conclusions: Our results indicate that cardiac markers in routine care are subject to extensive overutilization when used within LOPs. Educational measures are an effective strategy to overcome the overutilization of cardiac markers but may be more effective when combined with the removal of cardiac markers from LOPs.

Genetic Components of 25-Hydroxyvitamin D Increase in Three Randomized Controlled Trials.

The 25-Hydroxyvitamin D (25[OH)D) serum concentration depends on vitamin D intake, endogenous vitamin D production and genetic factors. The latter have been demonstrated in large genome-wide association studies indicating that single nucleotide polymorphisms (SNPs) in genes related to the vitamin D metabolism are as important for serum 25(OH)D levels as the influence of season. The mechanism on how these SNPs influence serum 25(OH)D levels are still unclear. The aim of the present study was to investigate the genetic effects of ten selected SNPs related to vitamin D metabolism on 25-hydroxyvitamin D increase (∆25(OH)D) after vitamin D supplementation in three randomized controlled trials. Genotypes of SNPs related to vitamin D metabolism were determined in 411 participants with 25(OH)D concentrations < 75 nmol/l receiving 20,000 IU cholecalciferol per week for 8 or 12 weeks after study inclusion. For the vitamin D receptor (VDR) rs10783219 polymorphism, the minor A-allele was associated with lower ∆25(OH)D values in the entire study population (p = 0.022), which was not consistent in all three cohorts when analysed separately. VDR rs10783219 might therefore be a genetic modulator of increasing 25-hydroxyvitamin D concentrations. Considering the wide-spread use of vitamin D supplementation, future large and well-designed randomized controlled trials (RCTs) should investigate the clinical impact of this polymorphism.

Inappropriate use of laboratory tests: How availability triggers demand - Examples across Europe.

INTRODUCTION: The appropriate use of laboratory diagnostics is increasingly at stake. The aim of this study was to depict some paradigmatic examples of under- and overutilization, as well as possible solutions across Europe. METHODS: We collected six examples from five European countries where a rise or decline of orders for specific laboratory parameters was observed after organizational changes but without evidence of changes in patient collective characteristics as source of this variation. RESULTS: The collected examples were the following: 1-Germany) Switch from a Brain-Natriuretic-Peptide assay to NT-pro Brain-Natriuretic-Peptide assay, resulting in a 374% increase in these analytics; 2-Spain) Implementation of a gatekeeping strategy in tumor marker diagnostics, resulting in a 15-61% reduction of these diagnostics; 3-Croatia) Stepwise elimination of creatine-kinase-MB assay from the laboratory portfolio; 4-UK) Removal of γ-glutamyl transferase from a "liver function" profile, resulting in 82% reduction of orders; 5-Austria) Implementation of a new device for rapid Influenza-RNA detection, resulting in a 450% increase of Influenza testing; 6-Spain) Insourcing of 1,25-(OH)2-Vitamin D measurements, leading to a 378% increase of these analyses. CONCLUSION: The six paradigmatic examples described in this manuscript show that availability of laboratory resources may considerably catalyze the demand, thus underscoring that inappropriate use of laboratory resources may be commonplace in routine laboratories all across Europe and most probably beyond. They also demonstrate that the application of simple strategies may assist in overcoming this issue. We believe that laboratory specialists need to refocus on the extra-analytical parts of the testing process and engage more in interdisciplinary patient-care.