Reference intervals and percentiles for soluble transferrin receptor and sTfR/log ferritin index in healthy children and adolescents.

OBJECTIVES: Soluble transferrin receptor (sTfR) is a marker of both erythropoiesis and iron status and is considered useful for detecting iron deficiency, especially in inflammatory conditions, but reference intervals covering the entire pediatric age spectrum are lacking. METHODS: We studied 1,064 (48.5 % female) healthy children of the entire pediatric age spectrum to determine reference values and percentiles for sTfR and the ratio of sTfR to log-ferritin (sTfR-F index) using a standard immunoturbidimetric assay. RESULTS: Soluble TfR levels were highly age-specific, with a peak in infancy and a decline in adulthood, whereas the sTfR-F index was a rather constant parameter. There were positive linear relationships for sTfR with hemoglobin (Hb) (p=0.008) and transferrin (females p<0.001; males p=0.003). A negative association was observed between sTfR and ferritin in females (p<0.0001) and for transferrin saturation and mean corpuscular volume (MCV) in both sexes (both p<0.0001). We found a positive relationship between sTfR and body height, body mass index (BMI) and inflammatory markers (CrP p<0.0001; WBC p=0.0172), while sTfR-F index was not affected by inflammation. CONCLUSIONS: Soluble TfR values appear to reflect the activity of infant erythropoiesis and to be modulated by inflammation and iron deficiency even in a healthy cohort.

Normal Values for the fT3/fT4 Ratio: Centile Charts (0-29 Years) and Their Application for the Differential Diagnosis of Children with Developmental Delay.

Primary congenital hypothyroidism is easily diagnosed on the basis of elevated plasma levels of thyroid-stimulating hormone (TSH). In contrast, in the rare disorders of thyroid hormone resistance, TSH and, in mild cases, also thyroid hormone levels are within the normal range. Thyroid hormone resistance is caused by defects in hormone metabolism, transport, or receptor activation and can have the same serious consequences for child development as congenital hypothyroidism. A total of n = 23,522 data points from a large cohort of children and young adults were used to generate normal values and sex-specific percentiles for the ratio of free triiodothyronine (T3) to free thyroxine (T4), the fT3/fT4 ratio. The aim was to determine whether individuals with developmental delay and genetically confirmed thyroid hormone resistance, carrying defects in Monocarboxylate Transporter 8 (MCT8), Thyroid Hormone Receptor alpha (THRα), and Selenocysteine Insertion Sequence-Binding Protein 2 (SECISBP2), had abnormal fT3/fT4 ratios. Indeed, we were able to demonstrate a clear separation of patient values for the fT3/fT4 ratio from normal and pathological controls (e.g., children with severe cerebral palsy). We therefore recommend using the fT3/fT4 ratio as a readily available screening parameter in children with developmental delay for the identification of thyroid hormone resistance syndromes. The fT3/fT4 ratio can be easily plotted on centile charts using our free online tool, which accepts various SI and non-SI units for fT3, fT4, and TSH.

Free thyroxine measurement in clinical practice: how to optimize indications, analytical procedures, and interpretation criteria while waiting for global standardization.

Thyroid dysfunctions are among the most common endocrine disorders and accurate biochemical testing is needed to confirm or rule out a diagnosis. Notably, true hyperthyroidism and hypothyroidism in the setting of a normal thyroid-stimulating hormone level are highly unlikely, making the assessment of free thyroxine (FT4) inappropriate in most new cases. However, FT4 measurement is integral in both the diagnosis and management of relevant central dysfunctions (central hypothyroidism and central hyperthyroidism) as well as for monitoring therapy in hyperthyroid patients treated with anti-thyroid drugs or radioiodine. In such settings, accurate FT4 quantification is required. Global standardization will improve the comparability of the results across laboratories and allow the development of common clinical decision limits in evidence-based guidelines. The International Federation of Clinical Chemistry and Laboratory Medicine Committee for Standardization of Thyroid Function Tests has undertaken FT4 immunoassay method comparison and recalibration studies and developed a reference measurement procedure that is currently being validated. However, technical and implementation challenges, including the establishment of different clinical decision limits for distinct patient groups, still remain. Accordingly, different assays and reference values cannot be interchanged. Two-way communication between the laboratory and clinical specialists is pivotal to properly select a reliable FT4 assay, establish reference intervals, investigate discordant results, and monitor the analytical and clinical performance of the method over time.

Bone turnover in lactating and nonlactating women.

PURPOSE: During lactation, bone turnover increases, reflecting the mobilization of Calcium from maternal skeletal stores and resulting in bone loss. However, mechanisms are not yet fully understood, and previous studies have been comparatively small. We aim to assess bone metabolism during lactation by comparing bone-metabolism-related-parameters between large cohorts of lactating and nonlactating women. METHODS: In a retrospective cohort study, we recruited 779 postpartum women and 742 healthy, nonpregnant, nonlactating controls. Postpartum women were examined 3 and 6 months after delivery and retrospectively assigned to either the exclusively breastfeeding (exc-bf) group if they had exclusively breastfed or the nonexclusively breastfeeding (nonexc-bf) group if they had not exclusively breastfed up to the respective visit. Serum levels of PTH, Estradiol, total Calcium, Phosphate, and bone turnover markers (ßCTX, P1NP, Osteocalcin) were compared between the groups. RESULTS: Bone turnover markers were significantly increased in exc-bf and nonexc-bf women compared with the controls (all ps < .001). ßCTX was approximately twice as high in exc-bf women than in the controls. PTH levels were marginally higher in exc-bf (p < .001) and nonexc-bf women (p = .003) compared with the controls (6 months). Estradiol was suppressed in exc-bf women compared with the controls (p < .001, 3 months). CONCLUSION: Exc-bf and even nonexc-bf states are characterized by an increase in bone formation and resorption markers. The PTH data distribution of exc-bf, nonexc-bf, and control groups in the underpart of the reference range suggest that lactational bone loss is relatively independent of PTH.

Dubiously increased FT4 and FT3 levels in clinically euthyroid patients: clinical finding or analytical pitfall?

OBJECTIVES: We systematically investigated normally or subclinically increased thyroid stimulating hormone (TSH) values associated with unexpectedly increased thyroxine (FT4) and free triiodothyronine (FT3) in findings of patients without any thyroid disease. Moreover, we looked for alternatives to overcome such states with an improved diagnostic procedure and to investigate the pathogenetic background of the respective patients. METHODS: Samples with TSH concentrations within the range of 0.4-10 mU/L combined with increased concentrations of FT4 (n=120; Cobas, Roche) were collected over a period of around six years. Cobas FT4 results were compared with measurements from Liaison (DiaSorin) and Architect (Abbott) FT4 assays. For further validation all samples were measured for total thyroxine (TT4) (Cobas, Roche). Finally, FT3 and TT3 as complementary parameters were measured in samples with leftover material. To overcome potential analytical disturbances from stimulating heterophilic antibodies, we used heterophilic blocking tubes (HBTs). RESULTS: From the 120 samples with increased FT4 concentrations by Cobas, 51/120 were also increased by Liaison, and 26/120 by Architect. However, the measurement of TT4 indicated only n=10/120 increased values. The number of increased FT3 (n=71) measurements was higher in Architect>Cobas>Liaison (28>27>9). TT3 levels of 70/71 samples were within the reference interval. HBTs were inappropriate to reduce unspecific immunoreactivity in our samples. No clear pathogenetic background could be elucidated in the anamnesis of individual patients. CONCLUSIONS: To overcome dubious constellations of TSH, FT4, and FT3, it is helpful to measure TT4 and TT3 for control or to use an immunoassay with an alternative assay design for the respective parameters.

The novel cystatin C, lactate, interleukin-6, and N-terminal pro-B-type natriuretic peptide (CLIP)-based mortality risk score in cardiogenic shock after acute myocardial infarction.

BACKGROUND: Cardiogenic shock (CS) complicating acute myocardial infarction (AMI) still reaches excessively high mortality rates. This analysis is aimed to develop a new easily applicable biomarker-based risk score. METHODS AND RESULTS: A biomarker-based risk score for 30-day mortality was developed from 458 patients with CS complicating AMI included in the randomized CULPRIT-SHOCK trial. The selection of relevant predictors and the coefficient estimation for the prognostic model were performed by a penalized multivariate logistic regression analysis. Validation was performed internally, internally externally as well as externally in 163 patients with CS included in the randomized IABP-SHOCK II trial. Blood samples were obtained at randomization. The two trials are registered with ClinicalTrials.gov (NCT01927549 and NCT00491036), are closed to new participants, and follow-up is completed. Out of 58 candidate variables, the four strongest predictors for 30-day mortality were included in the CLIP score (cystatin C, lactate, interleukin-6, and N-terminal pro-B-type natriuretic peptide). The score was well calibrated and yielded high c-statistics of 0.82 [95% confidence interval (CI) 0.78-0.86] in internal validation, 0.82 (95% CI 0.75-0.89) in internal-external (temporal) validation, and 0.73 (95% CI 0.65-0.81) in external validation. Notably, it outperformed the Simplified Acute Physiology Score II and IABP-SHOCK II risk score in prognostication (0.83 vs 0.62; P < 0.001 and 0.83 vs. 0.76; P = 0.03, respectively). CONCLUSIONS: A biomarker-only score for 30-day mortality risk stratification in infarct-related CS was developed, extensively validated and calibrated in a prospective cohort of contemporary patients with CS after AMI. The CLIP score outperformed other clinical scores and may be useful as an early decision tool in CS.

Inclusion of 11-Oxygenated Androgens in a Clinical Routine LC-MS/MS Setup for Steroid Hormone Profiling.

11-Oxygenated androgens (11-OAs) are being discussed as potential biomarkers in diagnosis and therapy control of disorders with androgen excess such as congenital adrenal hyperplasia and polycystic ovary syndrome. However, quantification of 11-OAs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) still relies on extensive sample preparation including liquid-liquid extraction, derivatization and partial long runtimes, which is unsuitable for high-throughput analysis under routine laboratory settings. For the first time, an established online-solid-phase extraction-LC-MS/MS (online-SPE-LC-MS/MS) method for the quantitation of seven serum steroids in daily routine use was extended and validated to include 11-ketoandrostenedione, 11-ketotestosterone, 11ß-hydroxyandrostenedione and 11ß-hydroxytestosterone. Combining a simple protein precipitation step with fast chromatographic separation and ammonium fluoride-modified ionization resulted in a high-throughput method (6.6 min run time) featuring lower limits of quantification well below endogenous ranges (63-320 pmol/L) with recoveries between 85% and 117% (CVs ≤ 15%). Furthermore, the ability of this method to distinguish between adrenal and gonadal androgens was shown by comparing 11-OAs in patients with hyperandrogenemia to healthy controls. Due to the single shot multiplex design of the method, potential clinically relevant ratios of 11-OAs and corresponding androgens were readily available. The fully validated method covering endogenous concentration levels is ready to investigate the diagnostic values of 11-OAs in prospective studies and clinical applications.

Procalcitonin measured by three different assays is an excellent tumor marker for the follow-up of patients with medullary thyroid carcinoma.

OBJECTIVES: Procalcitonin (PCT) has been suggested as a tumor marker in patients with medullary thyroid carcinoma (MTC). Clinical application data in long term follow-up are missing. METHODS: 210 serum samples of 169 consecutive patients with MTC (92 sporadic, 77 hereditary, 158 postoperative follow-up, 11 preoperative) were collected between 2018 and 2020. Postoperative patients were stratified into three groups according to their disease status at the end of follow-up: cured (n=51, calcitonin (CT) levels < limit of quantitation), minimal residual disease (n=55, detectable CT and no metastases provable by imaging methods), metastatic disease (n=52). In five patients CT and PCT were measured while on therapy with tyrosine kinase inhibitors (TKI). CT was analyzed by the Roche ECLIA, PCT by three assays from Roche, PES, Abbott. RESULTS: The mean ± SD values seen with the three PCT assays in the MTC response groups, cured: <0.06, 0.016 ± 0.007, 0.014 ± 0.007 ng/mL, minimal residual disease: 0.511 ± 0.800, 0.389 ± 0.687, 0.341 ± 0.614 ng/mL, metastatic disease 109 ± 202, 60.4 ± 110, 63.3 ± 115 ng/mL correlate well with the CT results in these groups: cured <1.0 pg/mL, minimal residual disease 91.3 ± 121.5 pg/mL, metastatic disease 14,489 ± 30,772 pg/mL. There was a significant correlation (p<0.001) between the three PCT assays (Roche/PES r=0.970, Roche/Abbott r=0.976, Abbott/PES r=0.995). In the course of treatment with TKI both CT and PCT reflected clinical state. Preoperative PCT in hereditary MTC has the same diagnostic validity than CT. CONCLUSIONS: PCT measured with three different immunoassays is as good as the standard tumor marker CT in the follow-up of MTC but has a superior analytical stability.

Spot urine iodine levels below the WHO recommendation are not related to impaired thyroid function in healthy children and adolescents.

PURPOSE: Iodine deficiency in childhood and adolescence may lead to later thyroid dysfunction, stunted growth and cognitive impairment. The World Health Organization (WHO) has issued recommended age-dependent urine iodine concentration targets, but a critical threshold beyond which clinical sequelae are to be expected remains undefined. Our study aimed to investigate spot urine iodine concentration in a typical Central European cohort of children and adolescents, and consider the implications of these values in regard to laboratory parameters for evaluating thyroid function. METHODS: Using the Sandell-Kolthoff method, spot urine iodine concentration was measured cross-sectionally from 1802 healthy children and adolescent in the age range of 0.25-18 years within the LIFE-Child epidemiological study based in and around the city of Leipzig (Germany). Additionally, serum thyroid biomarkers of these subjects were measured and correlated to urine iodine levels. RESULTS: In our cohort, 61.39% of boys and 65.91% of girls had an iodine level of < 100 µg/L (57%, 67%, 65% of the age groups 0-5, 6-12 and 13-18 years), the median iodine excretion was 86 µg/L in boys and 80 µg/L in girls. The iodine levels revealed no significant correlation with the thyroid biomarkers TSH, FT4 and FT3. Moreover, iodine values revealed no correlation with levels of antibodies against thyroid peroxidase or thyroglobulin. CONCLUSION: In our cohort of children and adolescents, the relatively high number of iodine levels below the WHO recommendation appears not to be related to clinical or subclinical thyroid diseases in the respective participants.

The effect of depressive symptomatology on the association of vitamin D and sleep.

BACKGROUND: Sleep disorders and vitamin D deficiency are highly prevalent health problems. Few studies examined the effect of vitamin D concentrations on objectively measured sleep with high methodological quality and temporal proximity. Previous analysis within the LIFE-Adult-Study suggested that a lower concentration of serum vitamin D was associated with both shorter and later night sleep. However, no conclusion about underlying mechanisms could be drawn. We addressed the question whether this relationship is explained by the presence of depressive syndromes, which are linked to both vitamin D deficiency and sleep disturbances. METHODS: It was investigated whether the association of vitamin D concentrations and night sleep parameters is mediated or moderated by depressive symptomatology. We investigated a subset (n = 1252) of the community sample from the LIFE-Adult-Study, in which sleep parameters had been objectively assessed using actigraphy, based on which two sleep parameters were calculated: night sleep duration and midsleep time. Serum 25(OH) D concentrations were measured using an electrochemiluminescence immunoassay. Depressive symptomatology was evaluated with the Centre for Epidemiological Studies Depression Scale. The mediation effect was analyzed by using Hayes' PROCESS macro tool for SPSS for Windows. RESULTS: The depressive symptomatology was neither significantly associated with night sleep duration nor midsleep time. The associations between vitamin D concentrations and night sleep duration/midsleep time through mediation by depressive symptomatology were not significant. Corresponding moderator analyses were also non-significant. CONCLUSION: The associations between vitamin D concentrations and night sleep parameters (sleep duration and midsleep time) seem to be neither mediated nor moderated by depressive symptomatology.

Genome-wide meta-analysis identifies novel determinants of circulating serum progranulin.

Progranulin is a secreted protein with important functions in processes including immune and inflammatory response, metabolism and embryonic development. The present study aimed at identification of genetic factors determining progranulin concentrations. We conducted a genome-wide association meta-analysis for serum progranulin in three independent cohorts from Europe: Sorbs (N = 848) and KORA (N = 1628) from Germany and PPP-Botnia (N = 335) from Finland (total N = 2811). Single nucleotide polymorphisms (SNPs) associated with progranulin levels were replicated in two additional German cohorts: LIFE-Heart Study (Leipzig; N = 967) and Metabolic Syndrome Berlin Potsdam (Berlin cohort; N = 833). We measured mRNA expression of genes in peripheral blood mononuclear cells (PBMC) by micro-arrays and performed mRNA expression quantitative trait and expression-progranulin association studies to functionally substantiate identified loci. Finally, we conducted siRNA silencing experiments in vitro to validate potential candidate genes within the associated loci. Heritability of circulating progranulin levels was estimated at 31.8% and 26.1% in the Sorbs and LIFE-Heart cohort, respectively. SNPs at three loci reached study-wide significance (rs660240 in CELSR2-PSRC1-MYBPHL-SORT1, rs4747197 in CDH23-PSAP and rs5848 in GRN) explaining 19.4%/15.0% of the variance and 61%/57% of total heritability in the Sorbs/LIFE-Heart Study. The strongest evidence for association was at rs660240 (P = 5.75 × 10-50), which was also associated with mRNA expression of PSRC1 in PBMC (P = 1.51 × 10-21). Psrc1 knockdown in murine preadipocytes led to a consecutive 30% reduction in progranulin secretion. In conclusion, the present meta-GWAS combined with mRNA expression identified three loci associated with progranulin and supports the role of PSRC1 in the regulation of progranulin secretion.

Differential effects of endurance, interval, and resistance training on telomerase activity and telomere length in a randomized, controlled study.

Aims: It is unknown whether different training modalities exert differential cellular effects. Telomeres and telomere-associated proteins play a major role in cellular aging with implications for global health. This prospective training study examines the effects of endurance training, interval training (IT), and resistance training (RT) on telomerase activity and telomere length (TL). Methods and results: One hundred and twenty-four healthy previously inactive individuals completed the 6 months study. Participants were randomized to three different interventions or the control condition (no change in lifestyle): aerobic endurance training (AET, continuous running), high-intensive IT (4 × 4 method), or RT (circle training on 8 devices), each intervention consisting of three 45 min training sessions per week. Maximum oxygen uptake (VO2max) was increased by all three training modalities. Telomerase activity in blood mononuclear cells was up-regulated by two- to three-fold in both endurance exercise groups (AET, IT), but not with RT. In parallel, lymphocyte, granulocyte, and leucocyte TL increased in the endurance-trained groups but not in the RT group. Magnet-activated cell sorting with telomerase repeat-ampliflication protocol (MACS-TRAP) assays revealed that a single bout of endurance training-but not RT-acutely increased telomerase activity in CD14+ and in CD34+ leucocytes. Conclusion: This randomized controlled trial shows that endurance training, IT, and RT protocols induce specific cellular pathways in circulating leucocytes. Endurance training and IT, but not RT, increased telomerase activity and TL which are important for cellular senescence, regenerative capacity, and thus, healthy aging.

Central noradrenaline transporter availability is linked with HPA axis responsiveness and copeptin in human obesity and non-obese controls.

The central noradrenaline (NA) stress-response network co-mediates hypothalamic-pituitary-adrenal (HPA) axis activation and arginine-vasopressin (AVP) release. Dysregulation of these systems contributes to stress-related diseases such as human obesity, but their interrelation remains unclear. The study was aimed to test for the first time in vivo whether central noradrenergic activity quantitatively indexed by the availability of the presynaptic NA transporter (NAT) is associated with HPA axis responsiveness as measured with the combined dexamethasone suppression/corticotropin releasing hormone stimulation (dex/CRH) test and copeptin as a surrogate marker of the serum AVP tone in highly obese, otherwise, healthy individuals compared to age- and sex-matched non-obese, healthy controls. In order to assess central NAT availability, positron emission tomography (PET) was applied using the NAT-selective radiotracer S,S-[11C]O-methylreboxetine (MRB) and correlated with curve indicators derived from the dex/CRH test (maximum, MAX, and area under the curve, AUC, for cortisol and adrenocorticotropic hormone, ACTH) as well as with copeptin. In non-obese controls, positive correlations were found between the NAT distribution volume ratios (DVR) of the orbitofrontal cortex (OFC) and the amygdala with the HPA response (OFC: ACTHMAX r = 0.87, p = .001; cortisolMAX r = 0.86, p = .002; amygdala: ACTHMAX r = 0.86, p = .002; cortisolMAX r = 0.79, p = .006), while in obesity, the hypothalamic DVR correlated inversely with the HPA axis response (cortisolMAX, r = -0.66, p = .04) and with copeptin (r = -0.71, p = .02). This association of central NAT availability with HPA axis responsiveness and copeptin suggests a mechanistic interaction between noradrenergic transmission with HPA axis activity and the serum AVP system that differs between non-obese individuals with prefrontal-limbic involvement and obesity with a hypothalamic-centered relationship. Whether the latter finding contributes to obesogenic behavior needs to be further explored.

Stress-related hormones in association with periodontal condition in adolescents-results of the epidemiologic LIFE Child study.

OBJECTIVES: The aim of this study was to investigate the associations between blood levels of stress-related hormones and early signs of periodontal disease in children and adolescents. MATERIALS AND METHODS: Within the LIFE (Leipzig research center for civilization diseases) Child study, 498 adolescents (10 to 18 years) were included. Early signs of periodontal inflammation were measured by probing depth (PD) at six index teeth (16, 11, 26, 36, 31, 46). Blood levels of stress-related hormones (cortisol, dehydroepiandosterone-sulfate [DHEA-S]) and, additionally interleukine-6 (IL-6) were measured. Socioeconomic status, oral hygiene, orthodontic appliances, and nutritional status, recorded by body-mass-index-standard-deviation-score (BMI-SDS), were considered as confounding factors. Additionally, in 98 participants, an oral chairside active matrix metalloproteinase-8 (aMMP-8) test was performed. Statistical tests are the Mann-Whitney U tests, chi-squared tests and multivariate logistic regression model. RESULTS: IL-6, BMI-SDS as well as positive aMMP-8 test result were significantly associated with maximum PD > 3 mm (p < 0.05). However, no statistically significant associations between stress-related hormones (cortisol and DHEA-S) and presence of maximum PD > 3 mm were found (p > 0.05). Higher DHEA-S and BMI were associated with positive aMMP-8 result, even after adjusting for age and gender (p = 0.027, padj = 0.026). CONCLUSION: The results reveal no associations between PD and stress-related hormones cortisol and DHEA-S. aMMP-8 test result might be associated with DHEA-S level. Nutritional status seems to influence periodontal disease in adolescents. CLINICAL RELEVANCE: DHEA-S and BMI-SDS show associations with early signs of periodontal disease in adolescents aged 10 to 18 years. This association should be confirmed by the investigation of high-risk groups.

Sex hormones in association with general joint laxity and hypermobility in the temporomandibular joint in adolescents-results of the epidemiologic LIFE child study.

OBJECTIVES: The aim of this cross-sectional study was to investigate whether sex hormones (testosterone, oestradiol, sex-hormone-binding globulin = SHBG) are associated with general joint laxity (GJL) and hypermobility or derangements of the temporomandibular joint (TMJ) in adolescents. METHODS: Within the LIFE Child study, 970 adolescents (10-18 years) were included. GJL was assessed using the Beighton test. Maximum mouth opening (MMO) and clinical clicking sounds as signs of disc displacement (DD) in the TMJ were assessed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Serum levels of sex hormones were assessed using standardised laboratory analyses. RESULTS: Hypermobile joints were found in 54.9% (N = 532) of the sample; females were more affected than males (61.4% vs. 51.8%, P < 0.001). Using logistic regression analyses, the odds ratio (OR) for having >1 hypermobile joints increased to 1.15 (95% confidence interval [CI]: 1.04-1.27) in males and 1.09 (95% CI: 1.02-1.17) in females per 10 units of the SHBG serum level, compared to those without hypermobile joints-after controlling for the effect of age, adjusted BMI, pubertal development (Tanner scale), testosterone as well as oestradiol levels. Female subjects with >1 hypermobile joints showed a higher OR (1.89; 95% CI: 1.05-3.43) for having clinical clicking sounds in the TMJ and a 3.28 times higher OR (95% CI: 1.44-7.44) for MMO ≥ 55 mm. CONCLUSIONS: We observed age- and gender-independent associations of higher SHBG serum levels with GJL in adolescents. Moreover, hypermobile female adolescents show a more frequent hypermobility of the TMJ and clinical signs of DD.

A Rapid Chemiluminescence Assay for Measurement of Folate in Small Volumes of Breast Milk.

Early life exposure to folate has long lasting effects on development and health. Newborns obtain part of their folate from maternal milk. Studies on health effects of milk folate require rapid, affordable and reliable measurements in large numbers of samples from cohort studies. Recently, a competitive chemiluminescence assay for quantification of folate has become available for automated diagnostic measurement of folate in human serum or plasma. We tested if this method ("FOLA" from Siemens Healthcare) could also be used for human milk. To minimize interference and matrix effects, samples had to be skimmed, diluted seven times with demineralized water, and heated for 5 min at 90 °C. Folate could thus be measured in a linear range between 8.4 and 111.7 nM, with recoveries for the most relevant form, 5-methyltetrahydrofolate (5-MeTHF), of 96%-107%. Results were comparable to those with a recently validated Liquid Chromatography/Mass Spectrometry method (Y = 0.998X - 0.2; R2 = 0.807). The FOLA method was subsequently used for samples from the LIFE Child cohort in Germany, providing first data of breast milk folate in this country (range: 6.2-100.7 nM). This technique could indeed prove useful for large cohorts with multiple samplings.

Stress biomarkers in minimally invasive and conventional colorectal resections.

INTRODUCTION: Any surgical procedure develops a stress situation for the patient, which can modulate the individual outcome. At present, there is only limited information about stress response in colorectal resections by laparoscopic compared to conventional surgery. Therefore, our objectives were the feasibility and the investigation of stress biomarkers including copeptin and steroid hormones before, during and after colorectal surgery. METHODS: Eleven patients underwent minimally invasive and ten patients conventionally open colorectal surgery. Blood samples were collected before, during and 24 h after surgery and copeptin, NT-proBNP, cortisol, cortisone, interleukin-6 and glucose were analyzed. RESULTS: Both, minimally invasive and conventional-open colorectal surgery caused a fast but heterogeneous response of stress biomarkers. However, the postoperative decrease of cortisol, cortisone and glucose differed between both groups. The stress biomarkers decreased faster down to baseline after minimally invasive surgery, while in open surgery cortisol, cortisone and glucose did not return to baseline within 24 h after operation. CONCLUSIONS: We show in this feasibility study for the first time an increase of copeptin in combination with glucocorticoids as stress biomarkers by open surgery compared to minimally invasive procedures in patients undergoing colorectal surgery. Exceeding an individual threshold of 'stress burden' may have unfavorable effects on the long-time clinical outcome.

Effects of resveratrol on memory performance, hippocampus connectivity and microstructure in older adults - A randomized controlled trial.

INTRODUCTION: The polyphenol resveratrol has been suggested to exert beneficial effects on memory and the aging hippocampus due to calorie-restriction mimicking effects. However, the evidence based on human interventional studies is scarce. We therefore aimed to determine the effects of resveratrol on memory performance, and to identify potential underlying mechanisms using a broad array of blood-based biomarkers as well as hippocampus connectivity and microstructure assessed with ultra-high field magnetic resonance imaging (UHF-MRI). METHODS: In this double-blind, randomized controlled trial, 60 elderly participants (60-79 years) with a wide body-mass index (BMI) range of 21-37 kg/m2 were randomized to receive either resveratrol (200 mg/day) or placebo for 26 weeks (registered at ClinicalTrials.gov: NCT02621554). Baseline and follow-up assessments included the California Verbal Learning Task (CVLT, main outcome), the ModBent task, anthropometry, markers of glucose and lipid metabolism, inflammation and neurotrophins derived from fasting blood, multimodal neuroimaging at 3 and 7 T, and questionnaires to assess confounding factors. RESULTS: Multivariate repeated-measures ANOVA did not detect significant time by group effects for CVLT performance. There was a trend for preserved pattern recognition memory after resveratrol, while performance decreased in the placebo group (n.s., p = 0.07). Further exploratory analyses showed increases in both groups over time in body fat, cholesterol, fasting glucose, interleukin 6, high sensitive C-reactive protein, tumor necrosis factor alpha and in mean diffusivity of the subiculum and presubiculum, as well as decreases in physical activity, brain-derived neurotrophic factor and insulin-like growth factor 1 at follow-up, which were partly more pronounced after resveratrol. DISCUSSION: This interventional study failed to show significant improvements in verbal memory after 6 months of resveratrol in healthy elderly with a wide BMI range. A non-significant trend emerged for positive effects on pattern recognition memory, while possible confounding effects of unfavorable changes in lifestyle behavior, neurotrophins and inflammatory markers occurred. Our findings also indicate the feasibility to detect (un)healthy aging-related changes in measures of hippocampus microstructure after 6 months using 7T diffusion MRI. More studies incorporating a longer duration and larger sample size are needed to determine if resveratrol enhances memory performance in healthy older adults.

Serum concentrations of fetuin B in lipodystrophic patients.

OBJECTIVE: Fetuin B is an adipokine/hepatokine which is significantly elevated in insulin resistance/type 2 diabetes mellitus and hepatic steatosis. Regulation of fetuin B in patients with lipodystrophy (LD) - a disease group which is characterized by subcutaneous adipose tissue loss, hypertriglyceridemia, hepatic steatosis, insulin resistance, and dysregulation of several adipokines - has not been elucidated so far. MATERIAL AND METHODS: Serum fetuin B levels were determined in 37 patients with LD, as well as in a control cohort consisting of 37 non-LD participants matched for age, gender, and body mass index. Furthermore, fetuin B was correlated with parameters of lipid metabolism, glucose control, renal function, and inflammation. RESULTS: Median fetuin B serum levels were not significantly different between patients with LD (2980.7 µg/l; interquartile range: 841.7 µg/l) and non-LD controls (2647.3 µg/l; interquartile range: 923.6 µg/l; p = .105). Fetuin B was associated with age, body mass index, markers of renal function, and C reactive protein (CRP) in univariate correlation analyses. The associations with age and creatinine remained significant in multiple linear regression analysis. CONCLUSIONS: Fetuin B serum concentrations are not significantly different between patients with LD and non-LD controls. Fetuin B does not seem to be a major pathogenetic factor in LD.

Evaluation of hair cortisol and cortisone change during pregnancy and the association with self-reported depression, somatization, and stress symptoms.

Hair cortisol levels are used to measure long-term stress, while its inactive metabolite cortisone is often not assessed. We measured hair cortisol concentrations (HCC) and hair cortisone concentrations (HCNC) via liquid chromatography quadrupole linear ion trap mass spectrometry (LC-MS3) in 62 pregnant women who participated in the LIFE CHILD STUDY in their 2nd and 3rd trimester between 12/2011 and 11/2014. Sociodemographic factors, pregnancy-related factors, and hair characteristics were assessed. Degree of severity of depression, somatization, and stress were evaluated in both trimesters with a self-reported Patient Health Questionnaire (PHQ). Multivariate regression analyses were conducted between HCC and potential influencing factors, as well as with subscales of the PHQ, with HCNC and with the ratio of HCNC to HCC. Spearman correlation coefficients were calculated between steroid concentrations and subscale scores of the PHQ, as well as between the log2-fold change in HCC and HCNC and the change in PHQ subscale scores. HCC increased 1.3-fold and HCNC increased 1.5-fold by the 3rd trimester. HCNC was more than three times higher than HCC in both trimesters. We found significant associations of PHQ subscores with HCNC. The PHQ depression score was negatively correlated with HCNC in the 2nd trimester (p < .05). The PHQ stress score change was negatively correlated with the fold change of HCNC (p < .05) and with the change in the ratio of HCNC to HCC (p < .001). Our study suggests an association of cortisol/cortisone metabolism with self-reported stress in the 2nd and 3rd trimester of pregnancy. Since associations with PHQ subscores were only found with cortisone or the ratio of cortisone to cortisol, but not with cortisol alone, both cortisone and cortisol should be used as a marker for stress in pregnant woman.