Associations of 24 h urinary excretions of alpha- and gamma-carboxyethyl hydroxychroman with plasma alpha- and gamma-tocopherol and dietary vitamin E intake in older adults:the Lifelines-MINUTHE Study

Background Urinary metabolites of vitamin E, i.e., alpha- and gamma-carboxyethyl hydroxychroman (alpha- and gamma-CEHC), have gained increasing attention and have been proposed as novel biomarkers of vitamin E intake and status. However, there are insufficient data on the relationship of plasma alpha-tocopherol and gamma-tocopherol and dietary vitamin E intake with 24 h urinary excretions of alpha- and gamma-CEHC. Objectives We aimed to (1) investigate the associations of urinary alpha- and gamma-CEHC/creatinine ratios and 24 h urinary excretions of alpha- and gamma-CEHC with plasma alpha- and gamma-tocopherol, respectively; (2) investigate the associations of urinary alpha- and gamma-CEHC/creatinine ratios and 24 h urinary excretions of alpha- and gamma-CEHC with dietary vitamin E intake, and we hypothesize that 24 h urinary excretions of alpha- and gamma-CEHC will better correlate with vitamin E intake than urinary alpha- and gamma-CEHC/creatinine ratios. Design 24 h Urine and plasma samples were collected from 1519 participants (60-75 years, male: 50%) included in the Lifelines-MINUTHE Study for the assessments of urinary alpha- and gamma-CEHC/creatinine ratios and 24 h urinary excretions of alpha- and gamma-CEHC, and plasma alpha- and gamma-tocopherol. Among those participants, dietary vitamin E intake data from 387 participants were available from an externally validated Flower-Food Frequency Questionnaire (FFQ). The associations of plasma alpha- and gamma-tocopherol, dietary vitamin E intake, with urinary alpha- and gamma-CEHC were assessed using multivariate linear regressions. Results 24 h Urinary excretion of alpha-CEHC (median (IQR): 0.9 (0.3-2.4) mu mol) was less than that of gamma-CEHC (median (IQR): 1.5 (0.5-3.5) mu mol). After adjustment for covariates, we found that 24 h urinary alpha-CEHC excretion and urinary alpha-CEHC/creatinine ratio were both positively associated with plasma alpha-tocopherol (std.beta: 0.06, p = 0.02; std.beta: 0.06, p = 0.01, respectively). Furthermore, the sum of 24 h urinary alpha- and gamma-CEHC excretions was positively associated with dietary vitamin E intake (std.beta: 0.08; p = 0.03), whereas there was no relation between urinary alpha- and gamma-CEHC/creatinine ratios and vitamin E intake. No association was observed neither between plasma alpha- and gamma-tocopherol and dietary vitamin E intake, nor between urinary gamma-CEHC and plasma gamma-tocopherol. Conclusion Our study confirmed our hypothesis that 24 h urinary alpha- and gamma-CEHC excretions would be a better marker for dietary vitamin E intake than urinary alpha- and gamma-CEHC/creatinine ratios. Considering that both 24 h urinary alpha- and gamma-CEHC excretions and alpha- and gamma-CEHC/creatinine ratios were also associated with plasma alpha-tocopherol status, we suggest that 24 h urinary alpha- and gamma-CEHC excretions could be used to assess overall vitamin E status

Reference intervals for Sysmex XN hematological parameters as assessed in the Dutch Lifelines cohort

Our aim was to derive reference intervals for all Sysmex XN hematology analyzer parameters. The rationale behind the study was the lack of reference intervals for the XN analyzer cell population data (CPD) and functional parameters. Fresh fasting blood samples from 18,484 participants in the Dutch Lifelines study were analyzed using two automated XN analyzers. Structured health questionnaire data were used to select a subgroup of 15,803 apparently healthy individuals for inclusion in the reference population. The Latent Abnormal Values Exclusion (LAVE) approach was used to reduce the influence of latent diseases in the reference population on the resulting reference intervals. We applied analysis of variance to judge the need for partitioning of the reference intervals by sex or age. We report reference intervals for 105 XN analyzer hematological parameters with and without applying LAVE. Sex-related partitioning was required for red blood cells, (RBC, RBC-O), hemoglobin (HGB, HGB-O), hematocrit (HCT), mean corpuscular hemoglobin concentration (MCHC), reticulocyte production index (RPI), and side scattered light intensity of the red blood cell population in the RET channel (RBC-Z). Partitioning for age was not warranted. Body mass index (BMI) and smoking had moderate influence on a minority of the parameters. We provide reference intervals for all Sysmex XN analyzer routine, CPD and functional parameters, using a direct approach in a large cohort in the Netherlands

Circulating de novo lipogenesis fatty acids and all-cause mortality in a prospective Dutch population cohort

Background: Circulating fatty acids (FA) from de novo lipogenesis (DNL) are associated with all-cause mortality in individuals with elevated CVD risk. However, compared to FA early in the DNL synthetic pathway, cis-vaccenic acid, one of the FA distal in the DNL synthetic pathway, has rarely been studied in a general population cohort. We hypothesized that circulating cis-vaccenic acid is more strongly related to all-cause mortality than other circulating DNL-related FA. Objectives: The primary and secondary objectives of this study were to investigate the prospective associations of plasma levels of cis-vaccenic acid and other DNL-related FA with all-cause mortality in a general population, respectively. Methods: We included 850 participants (mean ± SD age 53 ± 15 years) from the Dutch Lifelines cohort study. Circulating levels of palmitic (C16:0), palmitoleic (C16:1n7), cis-vaccenic (cis-C18:1n7), stearic (C18:0), oleic acid (C18:1n9) in plasma phospholipids (PL) and triglycerides (TG) were measured by gas chromatography. The associations of circulating cis-C18:1n7 and other DNL-related FA with all-cause mortality were assessed using Cox regression analyses. Results: During a median follow-up of 9.3 (IQR: 5.4–10.8) years, 34 (4.0%) participants had died. In plasma PL, a 1-SD increase in cis-C18:1n7 was associated with an increased risk of all-cause mortality in univariate and multivariate models (p<0.02 for all), with a HR [95% CI] of 1.60 [1.13–2.25] after adjustment for age and sex. Conclusions: Circulating plasma PL cis-C18:1n7 was associated with a higher risk for all-cause mortality. More studies are needed in different cohorts to verify and validate our results

Plasma phospholipid fatty acid profile, estimated desaturase activities and prevalence of the metabolic syndrome in a general population cohort:A cross-sectional study

BACKGROUND: An altered plasma fatty acid (FA) profile and desaturase activities have been associated with several metabolic diseases, including the MetS, but studies in the general populations are lacking, and only few studies have investigated a broad spectrum of FA in plasma phospholipids (PL). OBJECTIVE: We investigated, cross-sectionally, the relationship of the FA profile and desaturase activities in plasma PL with the prevalence of MetS in a general population in The Netherlands. METHODS: Baseline characteristic data from 850 participants (Male: 50.2%) aged 38-68 years recruited in the Lifelines Cohort study were obtained. The FA profile was determined in fasting plasma PL, and desaturase activities were estimated from product/precursor ratios. The MetS was defined according to International Diabetes Federation. Logistic regressions were used to examine the relation of the FA profile with the prevalence of MetS, and Bonferroni correction was applied to account for multiple testing. RESULTS: 151 participants (17.7%) had the MetS. After adjustment for several confounders and Bonferroni correction, higher tertiles of C18 : 0 (the early precursor of de novo lipogenesis pathway), C18 : 3n6 and C20 : 3n6 (both consistent with a high Δ 6 desaturase (D6D) activity), and D6D activity itself were associated with a higher prevalence of MetS, while higher tertiles of C18 : 1n7, C24 : 0, and C24 : 1n9 (very-long-chain FA) as well as stearoyl-CoA desaturase (SCD)-18 were inversely associated with the MetS. CONCLUSIONS: This study shows that a wide-ranging plasma PL FA profile and estimated desaturase activities were different between adults with and without the MetS in a general representative population and implicates the importance of monitoring individual FAs and desaturase activities as novel modifiable biomarkers for the MetS

Methylmalonic acid, vitamin B12, renal function, and risk of all-cause mortality in the general population:results from the prospective Lifelines-MINUTHE study

Background: Methylmalonic acid (MMA) is best known for its use as a functional marker of vitamin B12 deficiency. However, MMA concentrations not only depend on adequate vitamin B12 status, but also relate to renal function and endogenous production of propionic acid. Hence, we aimed to investigate to what extent variation in MMA levels is explained by vitamin B12 and eGFR and whether MMA levels are associated with mortality if vitamin B12 and eGFR are taken into account. Methods: A total of 1533 individuals (aged 60–75 years, 50% male) were included from the Lifelines Cohort and Biobank Study. Individuals were included between 2006 and 2013, and the total follow-up time was 8.5 years. Results: Median [IQR] age of the study population was 65 [62–69] years, 50% was male. At baseline, median MMA concentration was 170 [138–216] nmol/L, vitamin B12 290 [224–362] pmol/L, and eGFR 84 [74–91] mL/min/1.73 m2. Log 2 vitamin B12, log 2 eGFR, age, and sex were significantly associated with log 2 MMA in multivariable linear regression analyses (model R 2 = 0.22). After a total follow-up time of 8.5 years, 72 individuals had died. Log 2 MMA levels were significantly associated with mortality (hazard ratio [HR] 1.67 [95% CI 1.25–2.22], P < 0.001). Moreover, we found a significant interaction between MMA and eGFR with respect to mortality (P interaction < 0.001). Conclusions: Only 22% of variation in MMA levels was explained by vitamin B12, eGFR, age, and sex, indicating that a large part of variation in MMA levels is attributable to other factors (e.g., catabolism, dietary components, or gut microbial production). Higher MMA levels are associated with an increased risk for mortality, independent of vitamin B12, eGFR, and sex. This association was more pronounced in individuals with impaired renal function

Age dependency of plasma vitamin B12 status markers in Dutch children and adolescents

BACKGROUND: Vitamin B12 deficiency in children may be associated with (severe) neurological manifestations, therefore recognition is important. Diagnosing vitamin B12 deficiency in children is challenging. This study aimed to investigate plasma methylmalonic acid, holotranscobalamin, and total cobalamin in children 0–18 years of age and to estimate age-dependent reference intervals. METHODS: Plasma vitamin B12 markers were measured in collected plasma samples of 170 children 0–18 years visiting a local primary care laboratory. All had within-reference hemoglobin and MCV values. Pediatric plasma vitamin B12 biomarkers were measured and reference values were derived thereof. RESULTS: Plasma methylmalonic acid was higher in young children, in particular between 1 and 6 months of age; total cobalamin and holotranscobalamin were highest from 0.5 to 4 years and decreased till 10 years of age. Plasma holotranscobalamin was highly correlated with plasma total cobalamin; their ratio was independent of age. Plasma methylmalonic acid was slightly more related to total cobalamin than to holotranscobalamin. A large proportion of mainly young children would be misclassified when adult references are applied. CONCLUSIONS: Pediatric reference values for cobalamin markers are necessary to allow for early recognition and monitoring of children suspect of (clinical) cobalamin deficiency. IMPACT: We analyzed three plasma vitamin B12 status markers, i.e., total cobalamin, holotranscobalamin, and methylmalonic acid, in the plasma of 170 children 0–18 years of age and were able to derive reference intervals thereof. Recognition of vitamin B12 deficiency in children is important but challenging as pediatric reference intervals for plasma vitamin B12 status markers, particularly plasma holotranscobalamin, are not well described. We think that our results may help early recognition and monitoring of children suspect of (clinical) vitamin B12 deficiency

Determination of reference intervals for urinary steroid profiling using a newly validated GC-MS/MS method

Background: Urinary steroid profiling (USP) is a powerful diagnostic tool to asses disorders of steroidogenesis. Preanalytical factors such as age, sex and use of oral contraceptive pills (OCP) may affect steroid hormone synthesis and metabolism. In general, USP reference intervals are not adjusted for these variables. In this study we aimed to establish such reference intervals using a newly-developed and validated gas chromatography with tandem mass spectrometry detection method (GC-MS/MS). Methods: Two hundred and forty healthy subjects aged 20-79 years, stratified into six consecutive decade groups each containing 20 males and 20 females, were included. None of the subjects used medications. In addition, 40 women aged 20-39 years using OCP were selected. A GC-MS/MS assay, using hydrolysis, solid phase extraction and double derivatization, was extensively validated and applied for determining USP reference intervals. Results: Androgen metabolite excretion declined with age in both men and women. Cortisol metabolite excretion remained constant during life in both sexes but increased in women 70-79 years of age. Progesterone metabolite excretion peaked in 30-39-year-old women and declined afterwards. Women using OCP had lower excretions of androgen metabolites, progesterone metabolites and cortisol metabolites. Method validation results met prerequisites and revealed the robustness of the GC-MS/ MS method. Conclusions: We developed a new GC-MS/MS method for USP which is applicable for high throughput analysis. Widely applicable age and sex specific reference intervals for 33 metabolites and their diagnostic ratios have been defined. In addition to age and gender, USP reference intervals should be adjusted for OCP use

Association of Plasma Concentration of Vitamin B-12 With All-Cause Mortality in the General Population in the Netherlands

Importance: Higher plasma concentrations of vitamin B12 have been associated with mortality in elderly and hospitalized populations, including patients with chronic kidney disease, but the association of plasma concentrations of vitamin B12 with mortality in the general population remains unclear. Objective: To investigate the association of plasma concentrations of vitamin B12 with all-cause mortality. Design, Setting, and Participants: This longitudinal cohort study used post hoc analysis to examine data from participants of the Prevention of Renal and Vascular End-stage Disease Study in Groningen, the Netherlands. Participants included individuals who completed the second screening visit beginning January 1, 2001, excluding those who were missing values of vitamin B12 plasma concentrations or used vitamin B12 supplementation. Follow-up time was defined between the beginning of the second screening round to end of follow-up on January 1, 2011. Data analysis was conducted from October 2, 2018, to February 22, 2019. Exposures: Plasma vitamin B12 concentration level. Main Outcomes and Measures: Death as recorded by the Central Bureau of Statistics of Groningen, the Netherlands. Results: A total of 5571 participants (mean [SD] age, 53.5 [12.0] years; 2830 [50.8%] men) were included in analyses. Median (interquartile range) plasma concentration of vitamin B12 was 394.42 (310.38-497.42) pg/mL. During the median (interquartile range) of 8.2 (7.7-8.9) years of follow-up, 226 participants (4.1%) died. According to quartiles of the distribution of plasma vitamin B12 concentration levels, mortality rates were 33.8 deaths per 10 000 person-years for the quartile with the lowest plasma concentration of vitamin B12 and 65.7 deaths per 10 000 person-years for the quartile with the highest plasma concentration of vitamin B12. After adjustment for multiple clinical and laboratory variables, Cox regression analyses found a significant association between higher vitamin B12 plasma concentration level and increased risk of all-cause mortality (hazard ratio per 1-SD increase, 1.25 [95% CI, 1.06-1.47]; P = .006). Conclusions and Relevance: These findings suggest that higher levels of plasma concentrations of vitamin B12 were associated with increased risk of all-cause mortality after adjusting for age, sex, renal function, and other clinical and laboratory variables. The mechanisms underlying this association remain to be established