Cohort profile: Biomarkers related to folate-dependent one-carbon metabolism in colorectal cancer recurrence and survival - the FOCUS Consortium

PURPOSE

The overarching goal of the FOCUS (biomarkers related to folate-dependent one-carbon metabolism in colorectal cancer (CRC) recurrence and survival) Consortium is to unravel the effect of folate and folate-mediated one-carbon metabolism (FOCM) biomarkers on CRC prognosis to provide clinically relevant advice on folate intake to cancer patients and define future tertiary prevention strategies.

PARTICIPANTS

The FOCUS Consortium is an international, prospective cohort of 2401 women and men above 18 years of age who were diagnosed with a primary invasive non-metastatic (stages I-III) CRC. The consortium comprises patients from Austria, two sites from the Netherlands, Germany and two sites from the USA. Patients are recruited after CRC diagnosis and followed at 6 and 12 months after enrolment. At each time point, sociodemographic data, data on health behaviour and clinical data are collected, blood samples are drawn.

FINDINGS TO DATE

An increased risk of cancer recurrences was observed among patients with higher compared with lower circulating folic acid concentrations. Furthermore, specific folate species within the FOCM pathway were associated with both inflammation and angiogenesis pathways among patients with CRC. In addition, higher vitamin B6 status was associated with better quality of life at 6 months post-treatment.

FUTURE PLANS

Better insights into the research on associations between folate and FOCM biomarkers and clinical outcomes in patients with CRC will facilitate the development of guidelines regarding folate intake in order to provide clinically relevant advice to patients with cancer, health professionals involved in patient care, and ultimately further tertiary prevention strategies in the future. The FOCUS Consortium offers an excellent infrastructure for short-term and long-term research projects and for combining additional biomarkers and data resulting from the individual cohorts within the next years, for example, microbiome data, omics and multiomics data or CT-quantified body composition data.

Changes in Tryptophan-Kynurenine Metabolism in Patients with Depression Undergoing ECT-A Systematic Review

The kynurenine pathway of tryptophan (Trp) metabolism generates multiple biologically active metabolites (kynurenines) that have been implicated in neuropsychiatric disorders. It has been suggested that modulation of kynurenine metabolism could be involved in the therapeutic effect of electroconvulsive therapy (ECT). We performed a systematic review with aims of summarizing changes in Trp and/or kynurenines after ECT and assessing methodological issues. The inclusion criterium was measures of Trp and/or kynurenines before and after ECT. Animal studies and studies using Trp administration or Trp depletion were excluded. Embase, MEDLINE, PsycInfo and PubMed were searched, most recently in July 2022. Outcomes were levels of Trp, kynurenines and ratios before and after ECT. Data on factors affecting Trp metabolism and ECT were collected for interpretation and discussion of the reported changes. We included 17 studies with repeated measures for a total of 386 patients and 27 controls. Synthesis using vote counting based on the direction of effect found no evidence of effect of ECT on any outcome variable. There were considerable variations in design, patient characteristics and reported items. We suggest that future studies should include larger samples, assess important covariates and determine between- and within-subject variability. PROSPERO (CRD42020187003).

Inflammation and cardiorespiratory fitness in overweight women and men: the FATCOR study

Background

Women have more body fat compared to men, and adipose tissue is associated with chronic inflammation. Cardiorespiratory fitness has on the other hand been postulated to lower chronic inflammation. However, sex-specific associations of inflammation with cardiorespiratory fitness is less studied.

Purpose

To assess inflammatory markers in overweight and obese women and men according to cardiorespiratory fitness in the FAT associated CardiOvasculaR dysfunction (FATCOR) study.

Methods

Cardiorespiratory fitness was assessed by maximal oxygen uptake (VO2max) by cardiopulmonary exercise testing in 566 subjects (mean age was 48±9 years, 60% women) with body mass index (BMI) >27.0 kg/m2. Participants were grouped according to sex, and fitness status identified from sex and age specific VO2max thresholds. C-reactive protein (CRP) and serum amyloid A (SAA) were analysed using Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight mass spectrometry. Serum levels of the kynurenine:tryptophan ratio (KTR) and pyriodoxic acid ratio (PAr) were measured by liquid chromatography tandem mass spectrometry. All inflammatory markers were log transformed before inclusion in linear regression analyses.

Results

In the total study population, 63% had obesity and 74% were cardiorespiratory unfit. Unfit women had the highest fat percentage and the highest serum levels of CRP and SAA compared to the other groups (p<0.05), while serum levels of KTR and PAr were higher only compared to fit men (p<0.05). In multivariable linear regression analyses in women, higher CRP (β −0.15, p=0.001), SAA (β −0.10, p=0.03) and PAr (β −0.09, p=0.03) were associated with lower VO2max after adjusting for age, fat percentage, hypertension and metabolic syndrome. In men, only higher PAr (β −0.14, p=0.02) was associated with lower VO2max in multivariable analyses adjusted for age, fat percentage and metabolic syndrome. In multivariable analyses in obese women only (n=213), higher CRP (β −0.15, p=0.01) and PAr (β −0.13, p=0.03) remained associated with lower VO2max, while in obese men (n=144) there was no significant associations between inflammatory markers and VO2max.

Conclusion

Among overweight subjects participating in the FATCOR study, cardiorespiratory unfit women had the highest serum levels of inflammatory markers. The association of inflammation with reduced cardiorespiratory fitness was more pronounced in women than men, in particular when obesity was present.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Western Regional Health Authority of Norway

Physical activity and risk of all-cause mortality in patients with stable angina pectoris: Effect modification by β-blocker treatment

Background

Physical activity (PA) influences sympathetic stimulation, platelet activation as well as vascular function, and has been associated with improved health outcomes in patients with coronary heart disease. β-blocker therapy reduces sympathetic activity and improves platelet and endothelial function. We investigated if β-blocker treatment modifies the association of self-reported PA with the risk of all-cause mortality.

Methods

A total of 2284 patients undergoing elective coronary angiography for suspected stable angina pectoris (SAP) were studied. Using Cox modeling, we examined associations between PA (categorized as 'sedentary/inactive', 'low', 'moderate', and 'high') and all-cause mortality according to β-blocker therapy.

Results

During a median follow-up of 10.3 years, 390 patients (17.1%) died. Higher PA was generally associated with a more favorable cardiovascular risk profile. Compared to the patients who were sedentary or inactive, the age and sex adjusted HRs (95% CI) for all-cause mortality were 0.89 (0.66-1.20), 0.73 (0.57-0.95) and 0.72 (0.55-0.95) in the low, moderate and high PA group, respectively. However, and notably, these risk estimates were 0.85 (0.60-1.20), 0.65 (0.47-0.89) and 0.58 (0.41-0.81) in β-blocker treated subjects vs. 1.00 (0.57-1.78), 0.96 (0.61-1.52) and 1.20 (0.74-1.95) in non-treated groups (P _interaction = 0.018). The results were essentially similar in the multivariable adjusted models.

Conclusions

In patients with suspected SAP, increased PA was associated with reduced mortality risk primarily in patients treated with β-blockers.

Biomarkers of the transsulfuration pathway and risk of renal cell carcinoma in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Previous studies have suggested that components of one-carbon metabolism, particularly circulating vitamin B6, have an etiological role in renal cell carcinoma (RCC). Vitamin B6 is a cofactor in the transsulfuration pathway. We sought to holistically investigate the role of the transsulfuration pathway in RCC risk. We conducted a nested case-control study (455 RCC cases and 455 matched controls) within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Plasma samples from the baseline visit were analyzed for metabolites of the transsulfuration pathway, including pyridoxal 5'-phosphate (PLP, the biologically active form of vitamin B6), homocysteine, serine, cystathionine, and cysteine, in addition to folate. Bayesian conditional logistic regression was used to estimate associations of metabolites with RCC risk as well as interactions with established RCC risk factors. Circulating PLP and cysteine were inversely associated with RCC risk, and these associations were not attenuated after adjustment for other transsulfuration metabolites (odds ratio (OR) and 90% credible interval (CrI) per 1 SD increase in log concentration: 0.76 [0.66, 0.87]; 0.81 [0.66, 0.96], respectively). A comparison of joint metabolite profiles suggested substantially greater RCC risk for the profile representative of low overall transsulfuration function compared to high function (OR 2.70 [90% CrI 1.26, 5.70]). We found some statistical evidence of interactions of cysteine with body mass index, and PLP and homocysteine with smoking status, on their associations with RCC risk. In conclusion, we found evidence suggesting that the transsulfuration pathway may play a role in metabolic dysregulation leading to RCC development.

Consumption of a light meal affects serum concentrations of one-carbon metabolites and B-vitamins. A clinical intervention study

The transfer of one-carbon units between molecules in metabolic pathways is essential for maintaining cellular homeostasis, but little is known about whether the circulating concentrations of metabolites involved in the one-carbon metabolism are affected by the prandial status. Epidemiological studies do not always consistently use fasting or non-fasting blood samples or may lack information on the prandial status of the study participants. Therefore, the main aim of the present study was to investigate the effects of a light breakfast on serum concentrations of selected metabolites and B-vitamins related to the one-carbon metabolism; i.e. the methionine-homocysteine cycle, the folate cycle, the choline oxidation pathway and the transsulfuration pathway. Sixty-three healthy adults (thirty-six women) with BMI ≥ 27 kg/m2 were included in the study. Blood was collected in the fasting state and 60 and 120 min after intake of a standardised breakfast consisting of white bread, margarine, white cheese, strawberry jam and orange juice (2218 kJ). The meal contained low amounts of choline, betaine, serine and vitamins B2, B3, B6, B9 and B12. Serum concentrations of total homocysteine, total cysteine, flavin mononucleotide, nicotinamide and pyridoxal 5'-phosphate were significantly decreased, and concentrations of choline, betaine, dimethylglycine, sarcosine, cystathionine and folate were significantly increased following breakfast intake (P < 0·05). Our findings demonstrate that the intake of a light breakfast with low nutrient content affected serum concentrations of several metabolites and B-vitamins related to the one-carbon metabolism.

The Association between Serum Serine and Glycine and Related-Metabolites with Pancreatic Cancer in a Prospective Cohort Study

Background. Serine and glycine play an important role in the folate-dependent one-carbon metabolism. The metabolism of serine and glycine has been shown to be associated with cancer cell proliferation. No prior epidemiologic study has investigated the associations for serum levels of serine and glycine with pancreatic cancer risk. Methods. We conducted a nested case-control study involved 129 incident pancreatic cancer cases and 258 individually matched controls within a prospective cohort study of 18,244 male residents in Shanghai, China. Glycine and serine and related metabolites in pre-diagnostic serum were quantified using gas chromatography-tandem mass spectrometry. A conditional logistic regression method was used to evaluate the associations for serine, glycine, and related metabolites with pancreatic cancer risk with adjustment for potential confounders. Results: Odds ratios (95% confidence intervals) of pancreatic cancer for the highest quartile of serine and glycine were 0.33 (0.14−0.75) and 0.25 (0.11−0.58), respectively, compared with their respective lowest quartiles (both p’s < 0.01). No significant association with risk of pancreatic cancer was observed for other serine- or glycine related metabolites including cystathionine, cysteine, and sarcosine. Conclusion. The risk of pancreatic cancer was reduced by more than 70% in individuals with elevated levels of glycine and serine in serum collected, on average, more than 10 years prior to cancer diagnosis in a prospectively designed case-control study. These novel findings support a protective role of serine and glycine against the development of pancreatic cancer in humans that might have an implication for cancer prevention.

Higher vitamin B6 status is associated with improved survival among patients with stage I-III colorectal cancer

BACKGROUND

Folate-mediated 1-carbon metabolism requires several nutrients, including vitamin B6. Circulating biomarker concentrations indicating high vitamin B6 status are associated with a reduced risk of colorectal cancer (CRC). However, little is known about the effect of B6 status in relation to clinical outcomes in CRC patients.

OBJECTIVES

We investigated survival outcomes in relation to vitamin B6 status in prospectively followed CRC patients.

METHODS

A total of 2031 patients with stage I-III CRC participated in 6 prospective patient cohorts in the international FOCUS (folate-dependent 1-carbon metabolism in colorectal cancer recurrence and survival) Consortium. Preoperative blood samples were used to measure vitamin B6 status by the direct marker pyridoxal 5'-phosphate (PLP), as well as the functional marker HK-ratio (HKr)[3'-hydroxykynurenine: (kynurenic acid + xanthurenic acid + 3'-hydroxy anthranilic acid + anthranilic acid)]. Using Cox proportional hazards regression, we examined associations of vitamin B6 status with overall survival (OS), disease-free survival (DFS), and risk of recurrence, adjusted for patient age, sex, circulating creatinine concentrations, tumor site, stage, and cohort.

RESULTS

After a median follow-up of 3.2 y for OS, higher preoperative vitamin B6 status as assessed by PLP and the functional marker HKr was associated with 16-32% higher all-cause and disease-free survival, although there was no significant association with disease recurrence (doubling in PLP concentration: HROS, 0.68; 95% CI: 0.59, 0.79; HRDFS, 0.84; 95% CI: 0.75, 0.94; HRRecurrence, 0.96; 95% CI: 0.84, 1.09; HKr: HROS, 2.04; 95% CI: 1.67, 2.49; HRDFS, 1.56; 95% CI: 1.31, 1.85; HRRecurrence, 1.21; 95% CI: 0.96,1. 52). The association of PLP with improved OS was consistent across colorectal tumor site (right-sided colon: HROS, 0.75; 95% CI: 0.59, 0.96; left-sided colon: HROS, 0.71; 95% CI: 0.55, 0.92; rectosigmoid junction and rectum: HROS, 0.61; 95% CI: 0.47, 0.78).

CONCLUSION

Higher preoperative vitamin B6 status is associated with improved OS among stage I-III CRC patients.

Association of Markers of Inflammation, the Kynurenine Pathway and B Vitamins with Age and Mortality, and a Signature of Inflammaging

BACKGROUND

Inflammation is a key feature of aging. We aimed to (i) investigate the association of 34 blood markers potentially involved in inflammatory processes with age and mortality and (ii) develop a signature of "inflammaging."

METHODS

Thirty-four blood markers relating to inflammation, B vitamin status, and the kynurenine pathway were measured in 976 participants in the Melbourne Collaborative Cohort Study at baseline (median age = 59 years) and follow-up (median age = 70 years). Associations with age and mortality were assessed using linear and Cox regression, respectively. A parsimonious signature of inflammaging was developed and its association with mortality was compared with 2 marker scores calculated across all markers associated with age and mortality, respectively.

RESULTS

The majority of markers (30/34) were associated with age, with stronger associations observed for neopterin, cystatin C, interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), several markers of the kynurenine pathway and derived indices KTR (kynurenine/tryptophan ratio), PAr index (ratio of 4-pyridoxic acid and the sum of pyridoxal 5'-phosphate and pyridoxal), and HK:XA (3-hydroxykynurenine/xanthurenic acid ratio). Many markers (17/34) showed an association with mortality, in particular IL-6, neopterin, C-reactive protein, quinolinic acid, PAr index, and KTR. The inflammaging signature included 10 markers and was strongly associated with mortality (hazard ratio [HR] per SD = 1.40, 95% CI: 1.24-1.57, p = 2 × 10-8), similar to scores based on all age-associated (HR = 1.38, 95% CI: 1.23-1.55, p = 4 × 10-8) and mortality-associated markers (HR = 1.43, 95% CI: 1.28-1.60, p = 1 × 10-10), respectively. Strong evidence of replication of the inflammaging signature association with mortality was found in the Hordaland Health Study.

CONCLUSION

Our study highlights the key role of the kynurenine pathway and vitamin B6 catabolism in aging, along with other well-established inflammation-related markers. A signature of inflammaging based on 10 markers was strongly associated with mortality.

Biomarkers of inflammation and left ventricular remodelling in psoriasis patients treated with infliximab

Objective: Psoriasis is an immune mediated disorder associated with T cell activation and cardiovascular disease (CVD). We explored the association of inflammation with left ventricular (LV) remodelling in psoriasis patients receiving treatment with the tumour necrosis factor-α (TNF-α) blocker infliximab. Methods: Psoriasis patients (n = 47, age 47 ± 14 years, 66% men) and 99 control subjects without psoriasis (age 47 ± 11 years, 72% men) were examined by echocardiography in a cross-sectional study. LV remodelling was assessed by LV mass index for height in the allometric power of 2.7. Serum concentrations of C-reactive protein (CRP), serum amyloid A (SAA), neopterin, kynurenine:tryptophan ratio (KTR) and the pyridoxic acid ratio (PAr) index were measured. Results: Serum concentration of neopterin (p = .007) was higher in psoriasis patients, while the other inflammatory biomarkers had similar levels. LV mass index was lower in patients than controls (35.6 ± 9.6 g/m^2.7 vs. 40.3 ± 9.8 g/m^2.7, p = .008). In the total study population, serum SAA (β = 0.18, p = .02), KTR (β = 0.20, p = .02) and the PAr index (β = 0.26, p = .002) were all associated with higher LV mass index independent of age, sex, body mass index, hypertension, smoking, renal function and psoriasis. Also in psoriasis patients, higher SAA level (β = 0.34, p = .02), KTR (β = 0.32, p = .02) and the PAr index (β = 0.29, p = .05) were associated with higher LV mass index independent of body mass index, hypertension and diabetes. Conclusion: Higher levels of the inflammatory biomarkers SAA, KTR and the PAr index were associated with greater LV mass index in psoriasis patients, indicating a role of chronic inflammation in LV remodelling evident even during treatment with TNF-α blockers.

Neopterin and kynurenic acid as predictors of stroke recurrence and mortality: a multicentre prospective cohort study on biomarkers of inflammation measured three months after ischemic stroke

BACKGROUND

Chronic low-grade inflammation is associated with both ischemic stroke and sedentary behaviour. The aim of this study was to investigate the predictive abilities of biomarkers of inflammation and immune modulation associated with sedentary behaviour for ischemic stroke recurrence and mortality in a stroke population.

METHODS

Patients admitted to hospital for acute stroke were recruited to the prospective multicentre cohort study, the Norwegian Cognitive Impairment After Stroke (Nor-COAST) study, from May 2015 until March 2017. Patients with ischemic stroke, blood samples available from the three-month follow-up, and no stroke recurrence before the three-month follow-up were included. Serum was analysed for C-reactive protein (CRP) with high-sensitive technique, and plasma for interleukin-6 (IL-6), neopterin, pyridoxic acid ratio index (PAr-index: 4-pyridoxic acid: [pyrioxal+pyridoxal-5'-phosphate]) and kynurenic acid (KA). Ischemic stroke recurrence and death were identified by the Norwegian Stroke Registry and the Cause of Death Registry until 31 December 2018.

RESULTS

The study included 354 patients, 57% male, mean age 73 (SD 11) years, mean observation time 2.5 (SD 0.6) years, and median National Institute of Health Stroke Scale of 0 (IQR 1) at three months. CRP was associated with mortality (HR 1.40, CI 1.01, 1.96, p = 0.046), and neopterin was associated with the combined endpoint (recurrent ischemic stroke or death) (HR 1.52, CI 1.06, 2.20, p = 0.023), adjusted for age, sex, prior cerebrovascular disease, modified Rankin Scale, and creatinine. When adding neopterin and KA to the same model, KA was negatively associated (HR 0.57, CI 0.33, 0.97, p = 0.038), and neopterin was positively associated (HR 1.61, CI 1.02, 2.54, p = 0.040) with mortality. Patients with cardioembolic stroke at baseline had higher levels of inflammation at three months.

CONCLUSION

Neopterin might be a valuable prognostic biomarker in stroke patients. The use of KA as a measure of anti-inflammatory capacity should be investigated further.

TRIAL REGISTRATION

The study was registered at Clinicaltrials.gov ( NCT02650531 ). First posted on 08/01/2016.

Association of markers of vascular inflammation with blood pressure in midlife: the Hordaland Health Study

Background

Hypertension is a pro-inflammatory condition. A steeper rise in blood pressure (BP) has been observed in middle-aged women than men. However, sex-specific associations of vascular inflammation with midlife BP has not been much explored.

Purpose

To test the association of markers of vascular inflammation, including neopterin, kynurenin:tryptophan ratio (KTR) and high sensitive C-reactive protein (CRP) with BP.

Methods

Circulating levels of neopterin, KTR and CRP were measured in 2042 women and 1646 men aged 47–49 years from the community-based Hordaland Health study. The associations with systolic and diastolic BP were tested in sex-specific linear regression analyses and adjusted for body mass index, serum total- and high-density lipoprotein cholesterol, triglycerides, creatinine, physical activity, daily smoking and diabetes.

Results

Compared to men, women had lower average BP (124/72 vs. 131/78 mmHg, p&lt;0.001), higher plasma neopterin (7.5 vs 7.0 nmol/l, p&lt;0.001) and comparable plasma KTR and serum CRP (both p&gt;0.05). In multivariable analyses 1) higher neopterin was associated with higher diastolic BP in women, but not in men; 2) higher CRP was associated with higher systolic and diastolic BP in women, but not in men; 3) no association of higher KTR with BP was found in either sex (Table 1). A significant sex-interaction between neopterin and diastolic BP was found.

Conclusion

Among participants in the Hordaland Health study, higher circulating levels of neopterin and CRP with higher BP was found among women only, suggesting that vascular inflammation contributes to BP elevation in middle-aged women.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Bergen

Inflammation-Related Marker Profiling of Dietary Patterns and All-cause Mortality in the Melbourne Collaborative Cohort Study

BACKGROUND

Nutritional epidemiology research using self-reported dietary intake is prone to measurement error. Objective methods are being explored to overcome this limitation.

OBJECTIVES

We aimed to examine 1) the association between plasma markers related to inflammation and derive marker scores for dietary patterns [Mediterranean dietary score (MDS), energy-adjusted Dietary Inflammatory Index (E-DIITM), Alternative Healthy Eating Index 2010 (AHEI)] and 2) the associations of these marker scores with mortality.

METHODS

Weighted marker scores were derived from the cross-sectional association between 30 plasma markers and each dietary score (assessed using food-frequency questionnaires) using linear regression for 770 participants in the Melbourne Collaborative Cohort Study (aged 50-82 y). Prospective associations between marker scores and mortality (n = 249 deaths) were assessed using Cox regression (median follow-up: 14.4 y).

RESULTS

The MDS, E-DII, and AHEI were associated (P < 0.05) with 9, 14, and 11 plasma markers, respectively. Healthier diets (higher MDS and AHEI, and lower anti-inflammatory, E-DII) were associated with lower concentrations of kynurenines, neopterin, IFN-γ, cytokines, and C-reactive protein. Five of 6 markers common to the 3 dietary scores were components of the kynurenine pathway. The 3 dietary-based marker scores were highly correlated (Spearman ρ: -0.74, -0.82, and 0.93). Inverse associations (for 1-SD increment) were observed with all-cause mortality for the MDS marker score (HR: 0.84; 95% CI: 0.72-0.98) and the AHEI marker score (HR: 0.76; 95% CI: 0.66-0.89), whereas a positive association was observed with the E-DII marker score (HR: 1.18; 95% CI: 1.01-1.39). The same magnitude of effect was not observed for the respective dietary patterns.

CONCLUSIONS

Markers involved in inflammation-related processes are associated with dietary quality, including a substantial overlap between markers associated with the MDS, the E-DII, and the AHEI, especially kynurenines. Unfavorable marker scores, reflecting poorer-quality diets, were associated with increased mortality.

876Association of blood markers of inflammation, vitamin status and the kynurenine pathway with age and all-cause mortality

Background

Inflammation is a key feature of aging and a cause of numerous diseases. We investigated the association of 35 blood markers involved in inflammatory processes with age and mortality and developed a signature of ‘inflammaging’.

Methods

Thirty-five blood markers relating to the kynurenine pathway, vitamin status, and inflammation were measured in 976 participants in the Melbourne Collaborative Cohort Study at baseline (1990-1994, median age 59 years) and follow-up (2003-2007, median age 70 years). Associations of each marker with age and all-cause mortality were assessed using linear and Cox regression, respectively. A signature of inflammaging was obtained via Lasso regression of age on the markers and tested for association with mortality; we compared mortality associations for this signature and two weighted scores across all markers associated with age and mortality, respectively.

Results

Most markers (29/35) were associated with age, with strongest associations observed for cystatin C, neopterin, quinolinic acid, and the kynurenine/tryptophan ratio, PAr index, and 3-hydroxykynurenine/xanthurenic acid ratio. Many markers (14/35) showed strong associations with mortality in particular neopterin, quinolinic acid, HK/XA, PAr index, CRP, IL-6 and KTr. The inflammaging signature included six markers and showed strong association with mortality (HR = 1.5, 95%CI: 1.3-1.7), almost as strong as the association of weighted scores combining all measured markers.

Conclusions

Our study highlights the key role played by markers of the kynurenine pathway and vitamin B6 catabolism in aging, along with other well-established inflammation-related markers.

Key messages

A signature of ‘inflammaging’ based on 6 markers may be useful to better predict mortality.

Investigating novel biomarkers of immune activation and modulation in the context of sedentary behaviour: a multicentre prospective ischemic stroke cohort study

Background

Sedentary behaviour is associated with disease, but the molecular mechanisms are not understood. Valid biomarkers with predictive and explanatory properties are required. Therefore, we have investigated traditional and novel biomarkers of inflammation and immune modulation and their association to objectively measured sedentary behaviour in an ischemic stroke population.

Methods

Patients admitted to hospital with acute ischemic stroke were included in the multicentre Norwegian Cognitive Impairment After Stroke (Nor-COAST) study (n = 815). For this sub-study (n = 257), sedentary behaviour was registered 3 months after stroke using position transition data from the body-worn sensor, ActivPal®. Blood samples were analysed for high sensitive C-reactive protein (hsCRP), the cytokines interleukin-6 (IL-6) and 10 (IL-10), neopterin, tryptophan (Trp), kynurenine (kyn), kynurenic acid (KA), and three B6 vitamers, pyridoxal 5′-phosphate (PLP), pyridoxal (PL), and pyridoxic acid (PA). The kynurenine/tryptophan ratio (KTR) and the pyridoxic acid ratio index (PAr = PA: PL + PLP) were calculated.

Results

Of the 815 patients included in the main study, 700 attended the three-month follow-up, and 257 fulfilled the inclusion criteria for this study. Sedentary time was significantly associated with levels of hsCRP, IL-6, neopterin, PAr-index, and KA adjusted for age, sex, waist circumference, and creatinine. In a fully adjusted model including all the significant biomarkers except hsCRP (because of missing values), sedentary time was independently positively associated with the PAr-index and negatively with KA. We did not find an association between sedentary behaviour, IL-10, and KTR.

Conclusions

The PAr-index is known to capture several modes of inflammation and has previously shown predictive abilities for future stroke. This novel result indicates that the PAr-index could be a useful biomarker in future studies on sedentary behaviour and disease progression. KA is an important modulator of inflammation, and this finding opens new and exciting pathways to understand the hazards of sedentary behaviour.

Trial registration

The study was registered at Clinicaltrials.gov (NCT02650531). First posted 08/01/2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02343-0.

Abstract 756: The association between serum serine and glycine and related-metabolites with pancreatic cancer in two prospective cohort studies

Background. Serine and glycine play an important role in the folate-dependent one-carbon metabolism. The metabolism of serine and glycine has been shown to be associated with cancer cell proliferation. No prior epidemiologic study has investigated the associations for serum levels of serine, glycine and their related-metabolites with pancreatic cancer risk.

Methods. Two parallel nested case-control studies derived from the Shanghai Cohort Study (with 129 cases and 258 controls) and from the Singapore Chinese Health Study (with 58 cases and 104 controls), respectively, were conducted to examine these associations. Conditional logistic regression method was used to evaluate the associations between serine, glycine and related-matabolites with pancreatic cancer risk, adjusting for potential confounders (i.e., level of education, body mass index, smoking status, alcohol consumption, history of diabetes, serum cotinine concentration, serum pyridoxal 5'-phosphate concentration (PLP), and estimated glomerular filtration rate (eGFR)).

Results. In the two studies combined data, odds ratios and 95% confidence intervals of pancreatic cancer for the highest quartile of serine and glycine were 0.42 (0.23-0.78) and 0.39 (0.21-0.72), respectively, compared with the lowest quartile. No significant association with risk of pancreatic cancer was observed for other serine- or glycine related metabolites including cystathionine, cysteine, and sarcosine.

Conclusion. The novel observation for a statistically significant inverse association for serum serine and glycine with risk of pancreatic cancer supports a protective role of these metabolites in the folate pathway against the development of pancreatic cancer in humans. With the experimental data showing the impact of serine and glycine on gut microbiota composition, [YJM1] our findings suggest that the alteration of gut microbiota may play a contributing role in reducing the risk of pancreatic cancer.

Funding: The Singapore Chinese Health Study was supported by the National Institutes of Health (NIH) of the United States (grants # R01 CA144034 and UM1 CA182876). HN Luu was partially supported by the University of Pittsburgh Medical Center Hillman Cancer Center start-up grant. P Paragomi was supported by the NIH T32CA186873 training grant in cancer epidemiology and prevention. W-P Koh was partially supported by the National Medical Research Council, Singapore (NMRC/CSA/0055/2013).

Citation Format: Hung N. Luu, Renwei Wang, Pedram Paragomi, Joyce Y. Huang, Lesley M. Butler, Øivind Midttun, Arve Ulvik, Aizhen Jin, Yu-Tang Gao, Per M. Ueland, Woon-Puay Koh, Jian-Min Yuan. The association between serum serine and glycine and related-metabolites with pancreatic cancer in two prospective cohort studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 756.

A comparison of complementary measures of vitamin B6 status, function, and metabolism in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

BACKGROUND

Vitamin B6 insufficiency has been linked to increased risk of cancer and other chronic diseases. The circulating concentration of pyridoxal 5'-phosphate (PLP) is a commonly used measure of vitamin B6 status. Ratios of substrates indicating PLP coenzymatic function and metabolism may be useful complementary measures to further explore the role of vitamin B6 in health.

OBJECTIVES

We explored the sensitivity of 5 outcomes, namely PLP concentration, homocysteine:cysteine (Hcy:Cys), cystathionine:cysteine (Cysta:Cys), the 3´-hydroxykynurenine ratio (HKr), and the 4-pyridoxic acid ratio (PAr) to vitamin B6 intake as well as personal and lifestyle characteristics.

MEDTHODS

Dietary intake and biomarker data were collected from participants from 3 nested case-control studies within the European Prospective Investigation into Cancer and Nutrition (EPIC). Bayesian regression models assessed the associations of the 5 biomarker outcomes with vitamin B6 intake and personal and lifestyle covariates. Analogous models examined the relations of Hcy:Cys, Cysta:Cys, and HKr with PLP.

RESULTS

In total, 4608 participants were included in the analyses. Vitamin B6 intake was most strongly associated with PLP, moderately associated with Hcy:Cys, Cysta:Cys, and HKr, and not associated with PAr (fold change in marker given a doubling of vitamin B6 intake: PLP 1.60 [95% credible interval (CrI): 1.50, 1.71]; Hcy:Cys 0.87 [95% CrI: 0.84, 0.90]; Cysta:Cys 0.89 [95% CrI: 0.84, 0.94]; HKr 0.88 [95% CrI: 0.85, 0.91]; PAr 1.00 [95% CrI: 0.95, 1.05]). PAr was most sensitive to age, and HKr was least sensitive to BMI and alcohol intake. Sex and menopause status were strongly associated with all 5 markers.

CONCLUSIONS

We found that 5 different markers, capturing different aspects of vitamin B6-related biological processes, varied in their associations with vitamin B6 intake and personal and lifestyle predictors.

Quantifying Precision Loss in Targeted Metabolomics Based on Mass Spectrometry and Nonmatching Internal Standards

In mass spectrometry, reliable quantification requires correction for variations in ionization efficiency between samples. The preferred method is the addition of a stable isotope-labeled internal standard (SIL-IS). In targeted metabolomics, a dedicated SIL-IS for each metabolite of interest may not always be realized due to high cost or limited availability. We recently completed the analysis of more than 70 biomarkers, each with a matching SIL-IS, across four mass spectrometry-based platforms (one GC-MS/MS and three LC-MS/MS). Using data from calibrator and quality control samples added to 60 96-well trays (analytical runs), we calculated analytical precision (CV) retrospectively. The use of integrated peak areas for all metabolites and internal standards allowed us to calculate precision for all matching analyte (A)/SIL-IS (IS) pairs as well as for all nonmatching A/IS pairs within each platform (total n = 1442). The median between-run precision for matching A/IS across the four platforms was 2.7-5.9%. The median CV for nonmatching A/IS (corresponding to pairing analytes with a non-SIL-IS) was 2.9-10.7 percentage points higher. Across all platforms, CVs for nonmatching A/IS increased with increasing difference in retention time (Spearman's rho of 0.17-0.93). The CV difference for nonmatching vs matching A/IS was often, but not always, smaller when analytes and internal standards were close structural analogs.

Ttrimetyllysine and risk of new-onset atrial fibrillation in two large norwegian cohorts

Funding Acknowledgements

Type of funding sources: None.

Background/Aim

Increased plasma trimetyllysine (TML), a methylated amino acid, has recently been linked to higher risk of acute myocardial infarction (AMI). TML is also a precursor of trimethylamine-N oxide (TMAO), which has been linked to increased cardiovascular risk, including that of  atrial fibrillation (AF). We investigated the association between TML and new-onset AF in two large Norwegian cohorts.

Methods

The primary cohort consisted of 6396 participants in the community-based Hordaland Health Study (HUSK). The validation cohort consited of 2027 patients who underwent coronary angiography due to suspected stable angina pectoris in the Western Norway Coronary Angiography Cohort (WECAC). Information on new-onset AF was obtained by linking patient data to Norwegian public health registries. Risk associations were explored by Cox regression.

Results

During median (25th-75th percentile) follow-up of 10.9 (10.6-11.3) and 7.0 (6.3-8.6) years, 560 (8.8%) patients in the HUSK and 210 (10.4%) in the WECAC was diagnosed with AF.

In the HUSK, the age and gender adjusted HR (95 % CI) for the 4th vs. 1st plasma TML quartiles 1.84 (1.37-2.48) p &lt; 0.001. In multivariable models the association was only slightly attenuated. Correspondingsly, the age and gender adjusted HR (95% CI) for the 4th vs. 1st TML quartiles in the WECAC was 1.48 (0.96-2.27) p = 0.07.

Testing for collinearity between TMAO and TML revealed variance inflation factors between 1.0-1.1 in HUSK and WECAC, thus ruling out collinearity.

Conclusion

Plasma TML was associated with new-onset AF among subjects from the general population, and the relationship was independent from established AF risk factors. A similar trend was also seen in patients with suspected stable angina pectoris, strengthening our findings, which motivate further studies to explore potential pathophysiological relationships between one-carbon metabolism and cardiac arrhythmias

Circulating B-vitamin biomarkers and B-vitamin supplement use in relation to quality of life in patients with colorectal cancer: results from the FOCUS consortium

BACKGROUND

B vitamins have been associated with the risk and progression of colorectal cancer (CRC), given their central roles in nucleotide synthesis and methylation, yet their association with quality of life in established CRC is unclear.

OBJECTIVES

To investigate whether quality of life 6 months postdiagnosis is associated with: 1) circulating concentrations of B vitamins and related biomarkers 6 months postdiagnosis; 2) changes in these concentrations between diagnosis and 6 months postdiagnosis; 3) B-vitamin supplement use 6 months postdiagnosis; and 4) changes in B-vitamin supplement use between diagnosis and 6 months postdiagnosis.

METHODS

We included 1676 newly diagnosed stage I-III CRC patients from 3 prospective European cohorts. Circulating concentrations of 9 biomarkers related to the B vitamins folate, riboflavin, vitamin B6, and cobalamin were measured at diagnosis and 6 months postdiagnosis. Information on dietary supplement use was collected at both time points. Health-related quality of life (global quality of life, functioning scales, and fatigue) was assessed by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire 6 months postdiagnosis. Confounder-adjusted linear regression analyses were performed, adjusted for multiple testing.

RESULTS

Higher pyridoxal 5'-phosphate (PLP) was cross-sectionally associated with better physical, role, and social functioning, as well as reduced fatigue, 6 months postdiagnosis. Associations were observed for a doubling in the hydroxykynurenine ratio [3-hydroxykynurenine: (kynurenic acid + xanthurenic acid + 3-hydroxyanthranilic acid + anthranilic acid); an inverse marker of vitamin B6] and both reduced global quality of life (β = -3.62; 95% CI: -5.88, -1.36) and worse physical functioning (β = -5.01; 95% CI: -7.09, -2.94). Dose-response relations were observed for PLP and quality of life. No associations were observed for changes in biomarker concentrations between diagnosis and 6 months. Participants who stopped using B-vitamin supplements after diagnosis reported higher fatigue than nonusers.

CONCLUSIONS

Higher vitamin B6 status was associated with better quality of life, yet limited associations were observed for the use of B-vitamin supplements. Vitamin B6 needs further study to clarify its role in relation to quality of life.

Targeted Plasma Metabolic Profiles and Risk of Recurrence in Stage II and III Colorectal Cancer Patients: Results from an International Cohort Consortium

The identification of patients at high-risk for colorectal cancer (CRC) recurrence remains an unmet clinical need. The aim of this study was to investigate associations of metabolites with risk of recurrence in stage II/III CRC patients. A targeted metabolomics assay (128 metabolites measured) was performed on pre-surgery collected EDTA plasma samples from n = 440 newly diagnosed stage II/III CRC patients. Patients have been recruited from four prospective cohort studies as part of an international consortium: Metabolomic profiles throughout the continuum of CRC (MetaboCCC). Cox proportional hazard models were computed to investigate associations of metabolites with recurrence, adjusted for age, sex, tumor stage, tumor site, body mass index, and cohort; false discovery rate (FDR) was used to account for multiple testing. Sixty-nine patients (15%) had a recurrence after a median follow-up time of 20 months. We identified 13 metabolites that were nominally associated with a reduced risk of recurrence. None of the associations were statistically significant after controlling for multiple testing. Pathway topology analyses did not reveal statistically significant associations between recurrence and alterations in metabolic pathways (e.g., sphingolipid metabolism p = 0.04; pFDR = 1.00). To conclude, we did not observe statistically significant associations between metabolites and CRC recurrence using a well-established metabolomics assay. The observed results require follow-up in larger studies.

Microheterogeneity and preanalytical stability of protein biomarkers of inflammation and renal function

Protein biomarker microheterogeneity has attracted increasing attention in epidemiological and clinical research studies. Knowledge concerning the preanalytical stability of proteins is paramount to assess the biological significance of their proteoforms. We investigated the stability of the inflammatory markers C-reactive protein (CRP), serum amyloid A (SAA), and calprotectin (S100A8/9), and the renal function marker, cystatin C (CnC). In total 16 proteoforms were quantified by immuno-MALDI-TOF MS in EDTA plasma and serum samples from 15 healthy volunteers. Prior to analysis blood samples were stored at either room temperature from 1 h up to 8 days, or underwent up to 9 consecutive freeze/thaw cycles. Pearson's correlation coefficient and t-test, intra-class correlation coefficient (ICC), and Autoregressive Integrated Moving-Average (ARIMA) models were used to investigate the stability of proteoform concentrations and distributions in blood. Plasma and serum concentrations of CRP and SAA proteoforms were highly stable during room temperature exposure and repeated freeze/thaw cycles, demonstrating excellent reproducibility (ICC > 0.75), no serial dependency in ARIMA models, and stable distribution of proteoforms. Stability analyses for proteoforms of S100A8/9 and CnC identified only minor preanalytical changes in concentrations and distributions, and none of the proteoforms were produced during prolonged exposure to room temperature or repeated freezing/thawing. The four proteins and their proteoforms are stable during sub-optimal sample handling, and represent robust biomarker candidates for future biobank studies aimed at investigating the microheterogeneity of SAA, S100A8/9, and CnC in relation to inflammation, renal dysfunction and various clinical outcomes.

Fitness is associated with lower inflammatory markers in obesity: the FATCOR study

Background

Obesity is associated with chronic low-grade inflammation, but exercise has anti-inflammatory properties. It is unknown whether the anti-inflammatory effects of fitness may influence the obesity-associated inflammation.

Purpose

To assess levels of inflammatory markers in fit vs. unfit overweight and obese subjects without known cardiovascular disease.

Methods

Peak oxygen uptake (VO2max) was measured by treadmill cardiopulmonary exercise testing in 566 subjects (mean age 48±9 years, 60% women) with body mass index &gt;27.0 kg/m2 in the FAT associated CardiOvasculaR dysfunction (FATCOR) study. Fitness was defined from age- and sex adjusted reference levels of VO2max. Serum levels of C-reactive protein (CRP), serum amyloid A (SAA) and calprotectin were assessed by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight (MALDI-TOF) mass spectrometry and log transformed before inclusion in analyses.

Results

Fit subjects (n=147) were older and had less metabolic syndrome, obesity and hypertension compared to unfit subjects (n=419) (all p&lt;0.05). Serum levels of CRP and SAA were lower in fit subjects vs. unfit (p&lt;0.01), while serum calprotectin showed no difference (p=0.06). In multivariable logistic regression analyses, lower CRP (odds ratio [OR] 0.73, 95% confidence interval [CI] 0.61–0.87, p&lt;0.001) and SAA (OR 0.61, 95% CI 0.40–0.93, p=0.02) remained associated with being fit after adjusting for age, sex, obesity, metabolic syndrome and hypertension. When looking at obese (n=357, fit n=53) and overweight subjects (n=209, fit n=94) separately, lower CRP (OR 0.60, 95% CI 0.46–0.78, p&lt;0.001) and SAA (OR 0.44, 95% CI 0.24–0.83, p=0.01) remained associated with being fit in obese, but not in overweight subjects after adjustment for age, sex and metabolic syndrome.

Conclusion

Fitness was associated with lower circulatory inflammatory markers in obesity independent of cardiometabolic risk factors. Our results suggest that fitness may promote cardiovascular benefit through the anti-inflammatory properties of exercise also in obesity.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Western Norway Regional Health Authority

Circulating Folate and Folic Acid Concentrations: Associations With Colorectal Cancer Recurrence and Survival

BACKGROUND

Folates, including folic acid, may play a dual role in colorectal cancer development. Folate is suggested to be protective in early carcinogenesis but could accelerate growth of premalignant lesions or micrometastases. Whether circulating concentrations of folate and folic acid, measured around time of diagnosis, are associated with recurrence and survival in colorectal cancer patients is largely unknown.

METHODS

Circulating concentrations of folate, folic acid, and folate catabolites p-aminobenzoylglutamate and p-acetamidobenzoylglutamate were measured by liquid chromatography-tandem mass spectrometry at diagnosis in 2024 stage I-III colorectal cancer patients from European and US patient cohort studies. Multivariable-adjusted Cox proportional hazard models were used to assess associations between folate, folic acid, and folate catabolites concentrations with recurrence, overall survival, and disease-free survival.

RESULTS

No statistically significant associations were observed between folate, p-aminobenzoylglutamate, and p-acetamidobenzoylglutamate concentrations and recurrence, overall survival, and disease-free survival, with hazard ratios ranging from 0.92 to 1.16. The detection of folic acid in the circulation (yes or no) was not associated with any outcome. However, among patients with detectable folic acid concentrations (n = 296), a higher risk of recurrence was observed for each twofold increase in folic acid (hazard ratio = 1.31, 95% confidence interval = 1.02 to 1.58). No statistically significant associations were found between folic acid concentrations and overall and disease-free survival.

CONCLUSIONS

Circulating folate and folate catabolite concentrations at colorectal cancer diagnosis were not associated with recurrence and survival. However, caution is warranted for high blood concentrations of folic acid because they may increase the risk of colorectal cancer recurrence.

A prospective evaluation of serum methionine-related metabolites in relation to pancreatic cancer risk in two prospective cohort studies

Deficiencies in methyl donor status may render DNA methylation changes and DNA damage, leading to carcinogenesis. Epidemiological studies reported that higher dietary intake of choline is associated with lower risk of pancreatic cancer, but no study has examined the association of serum choline and its metabolites with risk of pancreatic cancer. Two parallel case-control studies, one nested within the Shanghai Cohort Study (129 cases and 258 controls) and the other within the Singapore Chinese Health Study (58 cases and 104 controls), were conducted to evaluate the associations of baseline serum concentrations of choline, betaine, methionine, total methyl donors (i.e., sum of choline, betaine and methionine), dimethylglycine and trimethylamine N-oxide (TMAO) with pancreatic cancer risk. In the Shanghai cohort, odds ratios and 95% confidence intervals of pancreatic cancer for the highest quartile of choline, betaine, methionine, total methyl donors and TMAO were 0.27 (0.11-0.69), 0.57 (0.31-1.05), 0.50 (0.26-0.96), 0.37 (0.19-0.73) and 2.81 (1.37-5.76), respectively, compared to the lowest quartile. The corresponding figures in the Singapore cohort were 0.85 (0.23-3.17), 0.50 (0.17-1.45), 0.17 (0.04-0.68), 0.33 (0.10-1.16) and 1.42 (0.50-4.04). The inverse associations of methionine and total methyl donors including choline, betaine and methionine with pancreatic cancer risk in both cohorts support that DNA repair and methylation play an important role against the development of pancreatic cancer. In the Shanghai cohort, TMAO, a gut microbiota-derived metabolite of dietary phosphatidylcholine, may contribute to higher risk of pancreatic cancer, suggesting a modifying role of gut microbiota in the dietary choline-pancreatic cancer risk association.