Urinary Betaine Research Articles

Determination of six arsenic species in urine by high-performance liquid chromatography-inductively coupled plasma-mass spectrometr

Objective: Establishing an analysis method for the detection of six arsenic compounds trivalent arsenic, pentavalent arsenic, methyl arsenic, dimethyl arsenic, arsenical choline and arsenical betaine in urine by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and providing a theoretical basis for health assessment of arsenic poisoning patients. Methods: HPLC-ICP-MS was used to detect six arsenic compounds with the hamilton PRP-X100 column and aqueous ammonium phosphate in a gradient elution as mobile phase. Results: There was a good linear relationship in the selected range of six arsenic compounds evidenced by a linear correlation coefficient greater than 0.999. The detection limit of 6 arsenic compounds was 0.46~0.57 μg/L, and the minimum quantitative concentration were 1.52~1.91 μg/L. The recovery rates of six arsenic compounds were 96.5%~106.4%, The within-run and between-run relative standard deviation was 2.9%~6.2% and 3.8%~8.7%. Conclusion: The established method with high accuracy and precision is suitable for detecting arsenic levels in urine of occupational arsenic exposure population.

Betaine insufficiency and reduced betaine dependent remethylation are associated with hyperhomocysteinemia, oxidative stress and mitochondrial damage in early Polycystic Kidney Disease

Polycystic kidney disease (PKD) is the most common monogenic kidney disorder and an important cause of end stage renal disease. Vascular abnormalities are the most important non‐cystic complication and contribute to renal disease progression. Homocysteine (Hcy)‐mediated endothelial dysfunction (ED) and oxidative stress are evident early on, but the underlying mechanisms remain unknown. We hypothesized that abnormalities in Hcy metabolism are responsible for the increased levels, leading to Hcy‐induced ED from early stages of PKD.MethodsWe investigated the Hcy metabolic pathway (transulfuration/remethylation fig. 1) and downstream effects ‐main sources of renal tubular (RT) and endothelial cell (EC) reactive oxygen species (ROS), NADPH oxidase 4, (NOX4) and mitochondria‐ in 4‐week‐old PCK and Sprague‐Dawley (SD) control rats (n=12 each). Kidneys were harvested, frozen in liquid nitrogen, or preserved in formalin for metabolomics and ex‐vivo studies. Twenty‐four‐hour urine and terminal blood samples were collected for metabolite analysis and chemistries. Plasma folic acid, vitamin B12, and Hcy were determined by ELISA. Hcy pathway metabolites (betaine, dimethylglycine) were determined by 1HNMR. Endothelial NO (eNOS) and oxidative stress were assessed by double immunofluorescence staining for CD31/eNOS and CD31/NOX4, respectively. RT and EC mitochondrial structure was assessed by electron microscopy.ResultsSerum creatinine and BUN remained unchanged, yet kidney weight/body weight ratio were increased in PCK. eNOS immunoreactivity was lower in PCK vs SD. Plasma Hcy and urine excretion of methyl donor betaine were elevated in PCK, and Hcy positively correlated with urine betaine. Plasma betaine was similar between the groups, but its tissue concentration was lower in PCK, which may lead to betaine insufficiency, impaired betaine dependent remethylation, and hyperhomocysteinemia. Contrarily, tissue glutathione concentration was higher in PCK vs SD, and plasma folate and vitamin B12 were similar, arguing against a defect in the transsulfuration or folate‐dependent remethylation pathways. RT NOX4 expression and immunoreactivity were increased in PCK compared to SD, in association with renal oxidative stress. PCK had increased number of CD31/NOX4 positive cells in peritubular capillaries, indicating increased EC ROS production. Collecting duct and EC mitochondria were swollen and showed cristae remodeling.ConclusionIn PKD, early elevation in Hcy is likely related to betaine insufficiency and impaired betaine‐dependent remethylation may be responsible for the early elevation of Hcy. NOX4 and mitochondria abnormalities may be important contributors to oxidative stress and disease severity. Our data suggests these may not only be early vascular disease markers, but also play an important pathogenic role in vascular complications associated with PKD, and contribute to renal disease progression.Support or Funding InformationR25‐DK101405, NIDDK P30 DK090728, NIDDK P30 DK 106912This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

High-Throughput Quantitation of Proline Betaine in Foods and Suitability as a Valid Biomarker for Citrus Consumption.

Proline betaine has been proposed as a candidate dietary biomarker for citrus intake. To validate its suitability as a dietary biomarker and to gain insight into the range of this per-methylated amino acid in foods and beverages, a quick and accurate stable isotope dilution assay was developed for quantitative high-throughput HILIC-MS/MS screening of proline betaine in foods and urine after solvent-mediated matrix precipitation. Quantitative analysis of a variety of foods confirmed substantial amounts of proline betaine in citrus juices (140-1100 mg/L) and revealed high abundance in tubers of the vegetable Stachys affinis, also known as Chinese artichocke (∼700 mg/kg). Seafood including clams, shrimp, and lobster contained limited amounts (1-95 mg/kg), whereas only traces were detected in fish, cuttlefish, fresh meat, dairy products, fresh vegetable (<3 mg/kg), coffee, tea, beer, and wine (<7 mg/L). The human excretion profiles of proline betaine in urine were comparable when common portions of orange juice or fried Stachys tubers were consumed. Neither mussels nor beer provided enough proline betaine to detect significant differences between morning urine samples collected before and after consumption. As Stachys is a rather rare vegetable and not part of peoples' daily diet, the data reported here will help to monitor the subject's compliance in future nutritional human studies on citrus products or the exclusion of citrus products in the wash-out phase of an intervention study. Moreover, proline betaine measurement can contribute to the establishment of a toolbox of valid dietary biomarkers reflecting wider aspects of diet to assess metabolic profiles as measures of dietary exposure and indicators of dietary patterns, dietary changes, or effectiveness of dietary interventions.

Plasma trimethylamine-N-oxide following supplementation with vitamin D or D plus B vitamins.

We compared the effect of supplementation with vitamin D + B or vitamin D on plasma trimethylamine N-oxide (TMAO) and choline metabolites. This is a randomized single-blinded nonplacebo-controlled study. Twenty-seven participants received 1200 IU vitamin D3 and 800 mg calcium, and 25 participants received additionally 0.5 mg folic acid, 50 mg B6, and 0.5 mg B12 for 1 year. Plasma homocysteine (Hcy), TMAO, and choline metabolites were measured at baseline and 12 months later. TMAO declined in the vitamin D arm by 0.5 versus 2.8 μmol/L in the D + B arm (p = 0.005). Hcy decreased and betaine increased in the D + B compared to the D arm. Within-subject levels of plasma choline and dimethylglycine and urine betaine increased in both arms and changes did not differ between the arms. TMAO reduction was predicted by higher baseline TMAO and lowering Hcy in stepwise regression analysis. The test-retest variations of TMAO were greater in the D + B arm compared to vitamin D arm. B vitamins plus vitamin D lowered plasma fasting TMAO compared to vitamin D. Vitamin D caused alterations in choline metabolism, which may reflect the metabolic flexibility of C1-metabolism. The molecular mechanisms and health implications of these changes are currently unknown.

Prospective Associations of Systemic and Urinary Choline Metabolites with Incident Type 2 Diabetes.

Several compounds in the choline oxidation pathway are associated with insulin resistance and prevalent diabetes; however, prospective data are scarce.We explored the relationships between systemic and urinary choline-related metabolites and incident type 2 diabetes in an observational prospective study among Norwegian patients. We explored risk associations by logistic regression among 3621 nondiabetic individuals with suspected stable angina pectoris, of whom 3242 provided urine samples. Reclassification of patients was investigated according to continuous net reclassification improvement (NRI >0). After median (25th to 75th percentile) follow-up of 7.5 (6.4-8.7) years, 233 patients (6.4%) were registered with incident type 2 diabetes. In models adjusted for age, sex, and fasting status, plasma betaine was inversely related to new-onset disease [odds ratio (OR) per 1 SD, 0.72; 95% CI, 0.62-0.83; P < 0.00001], whereas positive associations were observed for urine betaine (1.25; 1.09-1.43; P = 0.001), dimethylglycine (1.22; 1.06-1.40; P = 0.007), and sarcosine (1.30; 1.13-1.49; P < 0.001). The associations were maintained in a multivariable model adjusting for body mass index, hemoglobin A1c, urine albumin-to-creatinine ratio, estimated glomerular filtration rate, C-reactive protein, HDL cholesterol, and medications. Plasma betaine and urine sarcosine, the indices most strongly related to incident type 2 diabetes, improved reclassification [NRI >0 (95% CI) 0.33 (0.19-0.47) and 0.16 (0.01-0.31), respectively] and showed good within-person reproducibility. Systemic and urinary concentrations of several choline metabolites were associated with risk of incident type 2 diabetes, and relevant biomarkers may improve risk prediction.

Using NMR-Based Metabolomics to Evaluate Postprandial Urinary Responses Following Consumption of Minimally Processed Wheat Bran or Wheat Aleurone by Men and Women.

Wheat bran, and especially wheat aleurone fraction, are concentrated sources of a wide range of components which may contribute to the health benefits associated with higher consumption of whole-grain foods. This study used NMR metabolomics to evaluate urine samples from baseline at one and two hours postprandially, following the consumption of minimally processed bran, aleurone or control by 14 participants (7 Females; 7 Males) in a randomized crossover trial. The methodology discriminated between the urinary responses of control, and bran and aleurone, but not between the two fractions. Compared to control, consumption of aleurone or bran led to significantly and substantially higher urinary concentrations of lactate, alanine, N-acetylaspartate acid and N-acetylaspartylglutamate and significantly and substantially lower urinary betaine concentrations at one and two hours postprandially. There were sex related differences in urinary metabolite profiles with generally higher hippurate and citrate and lower betaine in females compared to males. Overall, this postprandial study suggests that acute consumption of bran or aleurone is associated with a number of physiological effects that may impact on energy metabolism and which are consistent with longer term human and animal metabolomic studies that used whole-grain wheat diets or wheat fractions.

Effects of high fructose and salt feeding on systematic metabonome probed via (1) H NMR spectroscopy.

Diets rich in high fructose and salt are increasingly popular in our daily life. A combination consumption of excessive fructose and salt can induce insulin resistance (IR) and hypertension (HT), which are major public health problems around the world. However, the effects of high fructose and salt on systematic metabonome remain unknown, which is very important for revealing the molecular mechanism of IR and HT induced by this dietary pattern. The metabolic profiling in urine, plasma, and fecal extracts from high fructose and salt-fed rats was investigated by use of (1) H nuclear magnetic resonance (NMR)-based metabonomics approach in this study. Multivariate analysis of NMR data showed the effects of high fructose and salt on the global metabonome. The metabolite analysis in urine and fecal extracts showed the time-dependent metabolic changes, which displayed metabonomic progression axes from normal to IR and HT status. The changes of 2-oxoglutarate, creatine and creatinine, citrate, hippurate, trimethylamine N-oxide (TMAO), and betaine in urine, together with gut microbiota disorder in feces, were observed at the preliminary formation stage of IR and HT (fourth week). At the severe stage (eighth week), the previously mentioned metabolic changes were aggravated, and the changes of lipid and choline metabolism in plasma suggested the increased risk of cardiovascular diseases. These findings provide an overview of biochemistry consequences of high fructose and salt feeding and comprehensive insights into the progression of systematic metabonome for IR and HT induced by this dietary pattern.

Variation of betaine, N,N-dimethylglycine, choline, glycerophosphorylcholine, taurine and trimethylamine-N-oxide in the plasma and urine of overweight people with type 2 diabetes over a two-year period.

Plasma betaine concentrations and urinary betaine excretions have high test-retest reliability. Abnormal betaine excretion is common in diabetes. We aimed to confirm the individuality of plasma betaine and urinary betaine excretion in an overweight population with type 2 diabetes and compare this with the individuality of other osmolytes, one-carbon metabolites and trimethylamine-N-oxide (TMAO), thus assessing their potential usefulness as disease markers. Urine and plasma were collected from overweight subjects with type 2 diabetes at four time points over a two-year period. We measured the concentrations of the osmolytes: betaine, glycerophosphorylcholine (GPC) and taurine, as well as TMAO, and the one-carbon metabolites, N,N-dimethylglycine (DMG) and free choline. Samples were measured using tandem mass spectrometry (LC-MS/MS). Betaine showed a high degree of individuality (or test-retest reliability) in the plasma (index of individuality = 0.52) and urine (index of individuality = 0.45). Betaine in the plasma had positive and negative log-normal reference change values (RCVs) of 54% and -35%, respectively. The other osmolytes, taurine and GPC were more variable in the plasma of individuals compared to the urine. DMG and choline showed high individuality in the plasma and urine. TMAO was highly variable in the plasma and urine (log-normal RCVs ranging from 403% to -80% in plasma). Betaine is highly individual in overweight people with diabetes. Betaine, its metabolite DMG, and precursor choline showed more reliability than the osmolytes, GPC and taurine. The low reliability of TMAO suggests that a single TMAO measurement has low diagnostic value.

Abstract P280: Urinary Hippurate and Proline Betaine Excretion relative to Fleshy Fruit Intake and Blood Pressure: The INTERMAP Study

Background: Intakes of biologically complex fleshy fruits with substantial variations in nutritional composition may be reflected in urinary metabolite differences. We evaluated 24 hr urinary hippurate and proline betaine relative to individual fruit intake and blood pressure (BP) among free-living individuals in a population-based study. Methods: Cross-sectional epidemiological and metabonomic data from the International Study of Macro-/Micronutrients and Blood Pressure were used, available for 4,276 men and women ages 40-59 years from China, Japan, United Kingdom, and United States. Fleshy fruit intakes, according to Stern’s botanical classification, were calculated from four in-depth 24 hr dietary recalls. Urinary spectra from timed 24 hr urine collections were obtained by 1H nuclear magnetic resonance spectroscopy. Peak intensities of urinary hippurate (δ 7.84, doublet) and proline betaine (δ 3.11, singlet) were quantified. Mean urinary metabolite excretions across quartiles of energy-adjusted fruit intakes and corresponding P for trend were calculated. Country-specific multivariable linear regression coefficients between urinary metabolites and sum of metabolite-related fruits were estimated and pooled, weighted by inverse of their variance. Results: Age-sex-sample adjusted Pearson correlations (r) were: between hippurate and raw fruits 0.17, fruit juice 0.01, urinary potassium 0.19, and dietary fiber 0.15; between proline betaine and raw fruit 0.27, fruit juice 0.30, vitamin C 0.40, sugar 0.21, and dietary fiber 0.16; between hippurate and proline betaine 0.02. Significant multivariable adjusted P for trends (metabolome-wide significance level; P&lt;4x10-6) across quartiles of intake were found between total raw fruit, apple, kiwi fruit, nectarine, peach, plum, dried apricot, dried prune and hippurate; similarly between raw fruit, fruit juice, banana, grapefruit, kumquat, orange, satsuma, tangerine, grapefruit juice, orange juice and proline betaine. Correlations between sum of metabolite-related fruits and hippurate were 0.24 (0.10 for sum of remaining fruits) and 0.64 with proline betaine (0.03 for remaining fruits). After multivariable adjustment including BMI, differences in systolic BP were for urinary hippurate higher by 2SD -1.53 mm Hg (95% CI: -2.32,-0.75) and for sum of hippurate-related fruits -0.60 (-1.32,0.12). Urinary proline betaine and sum of proline betaine-related fruits were not associated with BP. Conclusion: Consumption of several individual fruits was related to urinary hippurate and proline betaine excretion. Higher urinary hippurate excretion was associated with lower systolic BP, but this was not found for hippurate-related fruits. This suggests that other polyphenol-rich foods and/or quantity may be important in this relationship.

An integrated metabonomic approach to studying metabolic profiles in rat models with insulin resistance induced by high fructose.

Insulin resistance (IR) is a common risk factor for the development of metabolic diseases, and has gradually become a hot issue for research. It was reported that excessive feeding with high fructose induced insulin resistance in both humans and rats. The aim of this study was to investigate the progression of IR and identify potential biomarkers in urine, plasma and fecal extracts of high fructose-fed rats using a (1)H NMR-based metabonomics approach. The biochemical analysis was also performed. The levels of pyruvate and lactate in the plasma of the IR model rats were reduced significantly, and the levels of citrate and α-ketoglutaric acid (α-KG) in their urine, and the levels of succinate in their feces also decreased, suggesting perturbation of energy metabolism. Decreased levels of taurine in urine and fecal extracts during the whole experiment, together with increased levels of creatine/creatinine in urine, revealed liver and kidney injuries. Decreased levels of choline-containing metabolites in urine and increased levels of betaine in urine and plasma demonstrated altered transmethylation. Changes in hippurate, acetate, propionate and n-butyrate levels suggested disturbance of the intestinal flora in the IR rats. This study indicated that (1)H NMR-based metabonomics can provide biochemical information on the progression of IR and offers a non-invasive means for the discovery of potential biomarkers.

Assessment of Urinary Betaine as a Marker of Diabetes Mellitus in Cardiovascular Patients

Abnormal urinary excretion of betaine has been demonstrated in patients with diabetes or metabolic syndrome. We aimed to identify the main predictors of excretion in cardiovascular patients and to make initial assessment of its feasibility as a risk marker of future diabetes development. We used data from 2396 patients participating in the Western Norway B-vitamin Intervention Trial, who delivered urine and blood samples at baseline, and in the majority at two visits during follow-up of median 39 months. Betaine in urine and plasma were measured by liquid-chromatography-tandem mass spectrometry. The strongest determinants of urinary betaine excretion by multiple regression were diabetes mellitus, age and estimated glomerular filtration rate; all p<0.001. Patients with diabetes mellitus (n = 264) had a median excretion more than three times higher than those without. We found a distinct non-linear association between urinary betaine excretion and glycated hemoglobin, with a break-point at 6.5%, and glycated hemoglobin was the strongest determinant of betaine excretion in patients with diabetes mellitus. The discriminatory power for diabetes mellitus corresponded to an area under the curve by receiver-operating characteristics of 0.82, and betaine excretion had a coefficient of reliability of 0.73. We also found a significant, independent log-linear relation between baseline betaine excretion and the risk of developing new diabetes during follow-up. The good discriminatory power for diabetes, high test-retest stability and independent association with future risk of new diabetes should motivate further investigation on the role of betaine excretion in risk assessment and long-term follow-up of diabetes mellitus.

Plasma betaine concentrations correlate with plasma cortisol but not with C-reactive protein in an elderly population

Low plasma betaine concentrations are a feature of seriously ill patients. Increased dietary betaine intake has been associated with lowered systemic inflammation. We aimed to compare plasma cortisol (a stress marker) and C-reactive protein (an inflammation marker) as statistical predictors of plasma betaine concentrations. Plasma carnitine, cortisol and C-reactive protein concentrations, other biochemical measures and urine betaine excretion, were compared with plasma betaine concentration by correlation and in multiple regression models, using morning blood and urine samples from 64 ambulant elderly subjects and from 55 patients admitted to hospital with hip fractures. In the ambulant elderly without acute trauma, plasma cortisol (with negative coefficients) and carnitine (with positive coefficients) statistically predicted plasma betaine concentrations. C-reactive protein was not a predictor. In the patients, the significant predictors were plasma carnitine (positive coefficient) and plasma homocysteine (negative coefficient) and C-reactive protein again was not a predictor. In regression models using combined patient and control data there were large ranges of both cortisol and especially C-reactive protein; cortisol and homocysteine (negative coefficients) and carnitine (positive coefficient) were significant predictors but C-reactive protein was not significant. Stress rather than inflammation may affect plasma betaine concentrations.

Betaine and Secondary Events in an Acute Coronary Syndrome Cohort

BackgroundBetaine insufficiency is associated with unfavourable vascular risk profiles in metabolic syndrome patients. We investigated associations between betaine insufficiency and secondary events in acute coronary syndrome patients.MethodsPlasma (531) and urine (415) samples were collected four months after discharge following an acute coronary event. Death (34), secondary acute myocardial infarction (MI) (70) and hospital admission for heart failure (45) events were recorded over a median follow-up of 832 days.Principal FindingsThe highest and lowest quintiles of urinary betaine excretion associated with risk of heart failure (p = 0.0046, p = 0.013 compared with middle 60%) but not with subsequent acute MI. The lowest quintile of plasma betaine was associated with subsequent acute MI (p = 0.014), and the top quintile plasma betaine with heart failure (p = 0.043), especially in patients with diabetes (p<0.001). Top quintile plasma concentrations of dimethylglycine (betaine metabolite) and top quintile plasma homocysteine both associated with all three outcomes, acute MI (p = 0.004, <0.001), heart failure (p = 0.027, p<0.001) and survival (p<0.001, p<0.001). High homocysteine was associated with high or low betaine excretion in >60% of these subjects (p = 0.017). Median NT-proBNP concentrations were lowest in the middle quintile of plasma betaine concentration (p = 0.002).ConclusionsBetaine insufficiency indicates increased risk of secondary heart failure and acute MI. Its association with elevated homocysteine may partly explain the disappointing results of folate supplementation. In some patients, especially with diabetes, elevated plasma betaine also indicates increased risk.

Erratum to: Plasma betaine concentrations correlate with plasma cortisol but not with C-reactive protein in an elderly population

BACKGROUND Low plasma betaine concentrations are a feature of seriously ill patients. Increased dietary betaine intake has been associated with lowered systemic inflammation. We aimed to compare plasma cortisol (a stress marker) and C-reactive protein (an inflammation marker) as statistical predictors of plasma betaine concentrations. METHODS Plasma carnitine, cortisol and C-reactive protein concentrations, other biochemical measures and urine betaine excretion, were compared with plasma betaine concentration by correlation and in multiple regression models, using morning blood and urine samples from 64 ambulant elderly subjects and from 55 patients admitted to hospital with hip fractures. RESULTS In the ambulant elderly without acute trauma, plasma cortisol (with negative coefficients) and carnitine (with positive coefficients) statistically predicted plasma betaine concentrations. C-reactive protein was not a predictor. In the patients, the significant predictors were plasma carnitine (positive coefficient) and plasma homocysteine (negative coefficient) and C-reactive protein again was not a predictor. In regression models using combined patient and control data there were large ranges of both cortisol and especially C-reactive protein; cortisol and homocysteine (negative coefficients) and carnitine (positive coefficient) were significant predictors but C-reactive protein was not significant. CONCLUSIONS Stress rather than inflammation may affect plasma betaine concentrations.

The Contrasting Relationships between Betaine and Homocysteine in Two Clinical Cohorts are Associated with Plasma Lipids and Drug Treatments

BackgroundUrinary betaine excretion positively correlated with plasma homocysteine in outpatients attending a lipid disorders clinic (lipid clinic study). We aimed to confirm this in subjects with established vascular disease.MethodsThe correlation between betaine excretion and homocysteine was compared in samples collected from subjects 4 months after hospitalization for an acute coronary episode (ACS study, 415 urine samples) and from 158 sequential patients visiting a lipid disorders clinic.Principal findingsIn contrast to the lipid clinic study, betaine excretion and plasma homocysteine did not correlate in the total ACS cohort. Differences between the patient groups included age, non-HDL cholesterol and medication. In ACS subjects with below median betaine excretion, excretion correlated (using log transformed data) negatively with plasma homocysteine (r = −0.17, p = 0.019, n = 199), with no correlation in the corresponding subset of the lipid clinic subjects. In ACS subjects with above median betaine excretion a positive trend (r = +0.10) between betaine excretion and homocysteine was not significant; the corresponding correlation in lipid clinic subjects was r = +0.42 (p = 0.0001). In ACS subjects, correlations were stronger when plasma non-HDL cholesterol and betaine excretion were above the median, r = +0.20 (p = 0.045); in subjects above median non-HDL cholesterol and below median betaine excretion, r = −0.26 (p = 0.012). ACS subjects taking diuretics or proton pump inhibitors had stronger correlations, negative with lower betaine excretion and positive with higher betaine excretion.ConclusionsBetaine excretion correlates with homocysteine in subjects with elevated blood lipids.

Variability of plasma and urine betaine in diabetes mellitus and its relationship to methionine load test responses: an observational study

BackgroundSince betaine is an osmolyte and methyl donor, and abnormal betaine loss is common in diabetes mellitus (>20% patients), we investigated the relationship between betaine and the post-methionine load rise in homocysteine, in diabetes and control subjects. The post-methionine load test is reported to be both an independent vascular risk factor and a measure of betaine sufficiency.MethodsPatients with type 2 diabetes (n = 34) and control subjects (n = 17) were recruited. We measured baseline fasting plasma and 4-hour post-methionine load (L-methionine, 0.1 mg/kg body weight) concentrations of homocysteine, betaine, and the betaine metabolite N,N-dimethylglycine. Baseline urine excretions of betaine, dimethylglycine and glucose were measured on morning urine samples as the ratio to urine creatinine. Statistical determinants of the post-methionine load increase in homocysteine were identified in multiple linear regression models.ResultsPlasma betaine concentrations and urinary betaine excretions were significantly (p < 0.001) more variable in the subjects with diabetes compared with the controls. Dimethylglycine excretion (p = 0.00014) and plasma dimethylglycine concentrations (p = 0.039) were also more variable. In diabetes, plasma betaine was a significant negative determinant (p < 0.001) of the post-methionine load increase in homocysteine. However, it was not conclusive that this was different from the relationship in the controls. In the patients with diabetes, a strong relationship was found between urinary betaine excretion and urinary glucose excretion (but not with plasma glucose).ConclusionsBoth high and low plasma betaine concentrations, and high and low urinary betaine excretions, are more prevalent in diabetes. The availability of betaine affects the response in the methionine load test. The benefits of increasing betaine intake should be investigated.

Plasma betaine concentrations correlate with plasma cortisol but not with C-reactive protein in an elderly population

AbstractLow plasma betaine concentrations are a feature of seriously ill patients. Increased dietary betaine intake has been associated with lowered systemic inflammation. We aimed to compare plasma cortisol (a stress marker) and C-reactive protein (an inflammation marker) as statistical predictors of plasma betaine concentrations.Plasma carnitine, cortisol and C-reactive protein concentrations, other biochemical measures and urine betaine excretion, were compared with plasma betaine concentration by correlation and in multiple regression models, using morning blood and urine samples from 64 ambulant elderly subjects and from 55 patients admitted to hospital with hip fractures.In the ambulant elderly without acute trauma, plasma cortisol (with negative coefficients) and carnitine (with positive coefficients) statistically predicted plasma betaine concentrations. C-reactive protein was not a predictor. In the patients, the significant predictors were plasma carnitine (positive coefficient) and plasma homocysteine (negative coefficient) and C-reactive protein again was not a predictor. In regression models using combined patient and control data there were large ranges of both cortisol and especially C-reactive protein; cortisol and homocysteine (negative coefficients) and carnitine (positive coefficient) were significant predictors but C-reactive protein was not significant.Stress rather than inflammation may affect plasma betaine concentrations.

Plasma lipids and betaine are related in an acute coronary syndrome cohort.

BackgroundLow plasma betaine has been associated with unfavorable plasma lipid profiles and cardiovascular risk. In some studies raised plasma betaine after supplementation is associated with elevations in plasma lipids. We aimed to measure the relationships between plasma and urine betaine and plasma lipids, and the effects of lipid-lowering drugs on these.MethodologyFasting plasma samples were collected from 531 subjects (and urine samples from 415) 4 months after hospitalization for an acute coronary syndrome episode. In this cross-sectional study, plasma betaine and dimethylglycine concentrations and urine excretions were compared with plasma lipid concentrations. Subgroup comparisons were made for gender, with and without diabetes mellitus, and for drug treatment.Principal FindingsPlasma betaine negatively correlated with triglyceride (Spearman's rs = −0.22, p<0.0001) and non-high-density lipoprotein cholesterol (rs = −0.27, p<0.0001). Plasma betaine was a predictor of BMI (p<0.05) and plasma non-high-density lipoprotein cholesterol and triglyceride (p<0.001) independently of gender, age and the presence of diabetes. Using data grouped by plasma betaine decile, increasing plasma betaine was linearly related to decreases in BMI (p = 0.008) and plasma non-HDL cholesterol (p = 0.002). In a non-linear relationship betaine was negatively associated with elevated plasma triglycerides (p = 0.004) only for plasma betaine >45 µmol/L. Subjects taking statins had higher plasma betaine concentrations (p<0.001). Subjects treated with a fibrate had lower plasma betaine (p = 0.003) possibly caused by elevated urine betaine loss (p<0.001). The ratio of coenzyme Q to non-high-density lipoprotein cholesterol was higher in subjects with higher plasma betaine, and in subjects taking a statin.ConclusionLow plasma betaine concentrations correlated with an unfavourable lipid profile. Betaine deficiency may be common in the study population. Controlled clinical trials of betaine supplementation should be conducted in appropriate populations to determine whether correction affects cardiovascular risk.

Quantification of acetylcholine, choline, betaine, and dimethylglycine in human plasma and urine using stable-isotope dilution ultra performance liquid chromatography–tandem mass spectrometry

Disorders in choline metabolism are related to disease conditions. We developed a stable-isotope dilution ultra performance liquid chromatography–mass spectrometry (UPLC–MS/MS) method for the simultaneous quantification of acetylcholine (ACh), betaine, choline, and dimethylglycine (DMG). We used this method to measure concentrations of the analytes in plasma and urine in addition to other biological fluids after a protein precipitation by acetonitrile. The detection limits were between 0.35 nmol/L (for ACh in urine) and 0.34 μmol/L (for betaine in urine). ACh concentrations were not detectable in plasma. Intraassay and interassay coefficient of variation (CVs) were all <10.0% in biological fluids, except for DMG in cerebrospinal fluid (CV = 12.44%). Mean recoveries in urine pool samples were between 99.2% and 103.9%. The urinary excretion of betaine, choline, and DMG was low, with approximately 50.0% higher excretion of choline in females compared to males. Median urinary excretion of ACh were 3.44 and 3.92 μmol/mol creatinine in males and females, respectively ( p = 0.689). Plasma betaine concentrations correlated significantly with urinary excretions of betaine ( r = 0.495, p = 0.027) and choline ( r = 0.502, p = 0.024) in females. Plasma choline concentrations correlated significantly with urinary excretion of ACh in males ( r = 0.419, p = 0.041) and females ( r = 0.621, p = 0.003). The new method for the simultaneous determination of ACh, betaine, choline, and DMG is sensitive, precise, and fast enough to be used in clinical investigations related to the methylation pathway.

The clinical significance of betaine, an osmolyte with a key role in methyl group metabolism

Betaine is an essential osmolyte and source of methyl groups and comes from either the diet or by the oxidation of choline. Its metabolism methylates homocysteine to methionine, also producing N,N-dimethylglycine. Betaine insufficiency is associated with the metabolic syndrome, lipid disorders and diabetes, and may have a role in vascular and other diseases. Betaine is important in development, from the pre-implantation embryo to infancy. Betaine supplementation improves animal and poultry health, but the effect of long-term supplementation on humans is not known, though reports that it improves athletic performance will stimulate further studies. Subsets of the population that may benefit from betaine supplementation could be identified by the laboratory, in particular those who excessively lose betaine through the urine.Plasma betaine is highly individual, in women typically 20–60μmol/L and in men 25–75μmol/L. Plasma dimethylglycine is typically <10μmol/L. Urine betaine excretion is minimal, even following a large betaine dose. It is constant, highly individual and normally <35mmol/mole creatinine. The preferred method of betaine measurement is by LC-MS/MS, which is rapid and capable of automation. Slower HPLC methods give comparable results. Proton NMR spectrometry is another option but caution is needed to avoid confusion with trimethylamine-N-oxide.