Detection and quantification of sucrose as dietary biomarker using gas chromatography and liquid chromatography with mass spectrometry

Dietary biomarkers-an update on their validity and applicability in epidemiological studies

The aim of this literature review was to identify and provide a summary update on the validity and applicability of the most promising dietary biomarkers reflecting the intake of important foods in the Western diet for application in epidemiological studies. Many dietary biomarker candidates, reflecting intake of common foods and their specific constituents, have been discovered from intervention and observational studies in humans, but few have been validated. The literature search was targeted for biomarker candidates previously reported to reflect intakes of specific food groups or components that are of major importance in health and disease. Their validity was evaluated according to 8 predefined validation criteria and adapted to epidemiological studies; we summarized the findings and listed the most promising food intake biomarkers based on the evaluation. Biomarker candidates for alcohol, cereals, coffee, dairy, fats and oils, fruits, legumes, meat, seafood, sugar, tea, and vegetables were identified. Top candidates for all categories are specific to certain foods, have defined parent compounds, and their concentrations are unaffected by nonfood determinants. The correlations of candidate dietary biomarkers with habitual food intake were moderate to strong and their reproducibility over time ranged from low to high. For many biomarker candidates, critical information regarding dose response, correlation with habitual food intake, and reproducibility over time is yet unknown. The nutritional epidemiology field will benefit from the development of novel methods to combine single biomarkers to generate biomarker panels in combination with self-reported data. The most promising dietary biomarker candidates that reflect commonly consumed foods and food components for application in epidemiological studies were identified, and research required for their full validation was summarized.

Metabolomics-based profiling of anti-inflammatory compounds from Mentha spicata in shanghe, China

Mentha spicata is a popular herb used in foods, cosmetics, and medicines. In the present study, liquid chromatography-mass spectrometry-based metabolomics analysis and the zebrafish model were used to investigate the potential biomarkers of M. spicata growing in Shanghe County (Shandong Province, China) and their anti-inflammatory properties. Network pharmacology and molecular docking were performed to screen the main targets of the characteristic compounds to understand their mechanisms of action. Nine potential markers including sugars (1,2), polyphenolic acids (3-5), and flavonoids (6-9) were identified from the species. The inhibitory effects on leukocyte migration confirmed that compounds 1 and 3-9 played a positive role in the protective effect of Shanghe M. spicata (SM) extract against inflammation. Akt (protein kinase B), EGFR (epidermal growth factor receptor), and MMP9 (matrix metalloproteinase 9) were the core target proteins of the identified compounds in the anti-inflammatory process. The most significant Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment terms were response to abiotic stimulus (Biological Process), carbohydrate derivative binding (Molecular Function), and pathways in cancer. In docking simulations, 3-p-coumaroylquinic acid (3-PC, 4) and cirsimaritin (CN, 7) exhibited the highest potential affinity to the active sites of Akt and EGFR proteins, respectively; additionally, 5-demethylsinensetin (5-DS, 9) and luteolin (LN, 6) were considered the most suitable ligands for the MMP9 protein. The present study highlighted the use of SM resources as functional products with health benefits.

Development and validation of a UPLC-MS/MS method for the quantification of sugars and non-nutritive sweeteners in human urine

High-intensity sweeteners ('sweeteners'), such as sucralose, saccharine, acesulfame, cyclamate and steviol, are replacing sugars in many food products, but biomarker-based data on their population-wide exposure, as well as analytical methods that can quantify urinary concentrations of sugars and sweeteners simultaneously, are lacking. Here, we developed and validated an ultra-pressure liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) method to quantify glucose, sucrose, fructose, sucralose, saccharine, acesulfame, cyclamate and steviol glucuronide in human urine. Urine samples were prepared by a simple dilution step containing the internal standards in water and methanol. Separation was achieved on a Shodex Asahipak NH2P-40 hydrophilic interaction liquid chromatography (HILIC) column using gradient elution. The analytes were detected using electrospray ionization in negative ion mode, and selective reaction monitoring was optimized using the [M-H]- ions. Calibration curves ranged between 34 and 19,230 ng/mL for glucose and fructose, and 1.8 to 1,026 ng/mL for sucrose and the sweeteners. The method has acceptable accuracy and precision, which depends on the application of appropriate internal standards. Storage of urine samples in lithium monophosphate gives the best overall analytical performance, and storage at room temperature without any preservatives should be avoided since this leads to reduced glucose and fructose concentrations. With the exception of fructose, all analytes were stable throughout 3 freeze-thaw cycles. The validated method was applied to human urine samples, demonstrating quantifiable concentrations of the analytes which were in the expected range. It is concluded that the method has acceptable performance to quantitatively determine dietary sugars and sweeteners in human urine.

Sugars measured enzymatically in a fasting overnight urine sample are not sensitive biomarkers of dietary added sugar intake in postmenopausal women

BACKGROUND

Restricting dietary sugar is a leading recommendation, but limited biomarkers assessing intake exist. Although 24-h urinary sucrose (U-Suc) and urinary fructose (U-Fruc) excretion has been used with mixed success, collection is burdensome.

AIM

This study aimed to test the sensitivity of an enzymatic assay of U-Suc and U-Fruc to detect changing added sugar intake using low-burden overnight urine samples in 30 postmenopausal women.

METHODS

Women consumed usual dietary intake during day 1 and usual intake plus a sugar sweetened beverage during day 2. Weighed, photographed food records assessed intake. Enzymatic assay measured U-Suc and U-Fruc from fasting overnight samples; liquid chromatography mass spectrometry (LC-MS) validated U-Suc findings.

RESULTS

Dietary added sugars increased significantly during day 2 (p < 0.001), but urinary sugars were not significantly increased. Enzymatic assay detected urinary sugars in 75% (U-Suc) and 35% (U-Fruc) of samples. Dietary sucrose was not associated with U-Suc, however dietary fructose was significantly associated with U-Fruc [β = 0.031; p < 0.05] among women with detectable urinary sugars. Participants with detectable U-Fruc consumed more energy from added sugars [12.6% kcal day 1; 21.5% kcal day 2] than participants with undetectable U-Fruc [9.3% kcal day 1; 17.4% kcal day 2], p < 0.05. Using LC-MS, U-Suc predicted sucrose and added sugar intake [β = 0.017, β = 0.013 respectively; both p < 0.05].

CONCLUSIONS

Urinary sugars measured enzymatically from overnight urine samples were not sensitive biomarkers of changing added sugar intake in postmenopausal women. However, urinary fructose measured by enzymatic assay or LC-MS may differentiate low versus high added sugar consumers.

Relevance of fructose intake in adolescence for fatty liver indices in young adulthood

PURPOSE

To examine the association between fructose intake in adolescence and fatty liver indices (hepatic steatosis index (HSI), fatty liver index (FLI)) in young adulthood.

METHODS

Overall, 246 participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study who had a fasting blood sample in adulthood (18-36 years), at least two 3-day weighed dietary records for calculating fructose intakes and other fructose-containing sugars (total (TS), free (FS), added sugar (AS)) as well as two complete 24-h urine samples for calculating sugar excretion (fructose excretion (FE), fructose + sucrose excretion (FE + SE)) in adolescence (males: 9.5-16.5 years; females: 8.5-15.5 years) were analysed using multivariable linear regression analyses.

RESULTS

On the level of dietary intake, no prospective associations were observed between adolescent fructose intake and both adult fatty liver indices, whereas higher FS intakes were associated with lower levels of HSI (Ptrend = 0.02) and FLI (Ptrend = 0.03). On the urinary excretion level, however, a higher FE (Ptrend = 0.03) and FE + SE (Ptrend = 0.01) in adolescence were prospectively related to higher adult FLI values. No associations were observed between adolescent sugar excretion and adult HSI.

CONCLUSION

The present study does not provide unambiguous support for a detrimental impact of adolescent fructose intake on adult liver health. Nonetheless, further examinations estimating exposure by means of urinary excretion as well as dietary intake levels appear warranted.

The Prospective Association of Dietary Sugar Intake in Adolescence With Risk Markers of Type 2 Diabetes in Young Adulthood

Purpose: To examine the prospective relevance of dietary sugar intake (based on dietary data as well as urinary excretion data) in adolescent years for insulin sensitivity and biomarkers of inflammation in young adulthood.

Methods: Overall 254 participants of the DONALD study who had at least two 3-day weighed dietary records for calculating intakes of fructose, glucose, sucrose, total, free, added sugars, total sugars from sugar-sweetened beverages (SSB), juice, and sweets/sugar or at least two complete 24 h urine samples (n = 221) for calculating sugar excretion (urinary fructose and urinary fructose + sucrose) in adolescence (females: 9–15 years, males: 10–16 years) and a fasting blood sample in adulthood (18–36 years), were included in multivariable linear regression analyses assessing their prospective associations with adult homeostasis model assessment insulin sensitivity (HOMA2-%S) and a pro-inflammatory score (based on CRP, IL-6, IL-18, leptin, chemerin, adiponectin).

Results: On the dietary intake level, no prospective associations were observed between adolescent fructose, sucrose, glucose, added, free, total sugar, or total sugar from SSB, juice or sweets/sugar intake and adult HOMA2-%S (p > 0.01). On the urinary level, however, higher excreted fructose levels were associated with improved adult HOMA2-%S (p = 0.008) among females only. No associations were observed between dietary or urinary sugars and the adult pro-inflammatory score (p > 0.01).

Conclusion: The present study did not provide support that dietary sugar consumed in adolescence is associated with adult insulin sensitivity. The one potential exception was the moderate dietary consumption of fructose, which showed a beneficial association with adult fasting insulin and insulin sensitivity.

Sugar intake among German adolescents: trends from 1990 to 2016 based on biomarker excretion in 24-h urine samples

Trend analyses based on dietary records suggest decreases in the intakes of total sugar (TS), added and free sugar since 2005 among children and adolescents in Germany. In terms of age trends, TS intake decreased with increasing age. However, self-reported sugar intake in epidemiological studies is criticised, as it may be prone to bias due to selective underreporting. Furthermore, adolescents are more susceptible to underreporting than children. We thus analysed time and age trends in urinary fructose excretion (FE), sucrose excretion (SE) and the sum of both (FE + SE) as biomarkers for sugar intake among 8·5-16·5-year-old adolescents. Urinary sugar excretion was measured by UPLC-MS/MS in 997 24-h urine samples collected from 239 boys and 253 girls participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study cohort between 1990 and 2016. Time and age trends of log-transformed FE, SE and FE + SE were analysed using polynomial mixed-effects regression models. Between 1990 and 2016, FE as well as FE + SE decreased (linear time trend: P = 0·0272 and P < 0·0001, respectively). A minor increase in excretion during adolescence was confined to FE (linear age trend: P = 0·0017). The present 24-h excretion measurements support a previously reported dietary record-based decline in sugar intake since 2005. However, the previously seen dietary record-based decrease in TS from childhood to late adolescence was not confirmed by our biomarker analysis, suggesting a constant sugar intake for the period of adolescence.

Urinary Excretion of Sodium, Nitrogen, and Sugar Amounts Are Valid Biomarkers of Dietary Sodium, Protein, and High Sugar Intake in Nonobese Adolescents

Background: Objective indicators of dietary intake (e.g., biomarkers) are needed to overcome the limitations of self-reported dietary intake assessment methods in adolescents. To our knowledge, no controlled feeding studies to date have evaluated the validity of urinary sodium, nitrogen, or sugar excretion as dietary biomarkers in adolescents.Objective: This investigation aimed to evaluate the validity of urinary sodium, nitrogen, and total sugars (TS) excretion as biomarkers for sodium, protein, and added sugars (AS) intake in nonobese adolescents.Methods: In a crossover controlled feeding study design, 33 adolescents [12-18 y of age, 47 ± 25th percentile (mean ± SD) of body mass index (BMI; in kg/m²) for age] consumed 5% AS [low added sugars (LAS)] and 25% AS [high added sugars (HAS)] isocaloric, macronutrient-matched (55% carbohydrate, 30% fat, and 15% protein) diets for 7 d each, in a randomly assigned order, with a 4-wk washout period between diets. On the final 2 d of each diet period, 24-h urine samples were collected. Thirty-two adolescents completed all measurements (97% retention).Results: Urinary sodium was not different from the expected 90% recovery (mean ± SD: 88% ± 18%, P = 0.50). Urinary nitrogen was correlated with protein intake (r = 0.69, P < 0.001), although it was below the 80% expected recovery (62% ± 7%, P < 0.001). Urinary TS values were correlated with AS intake during the HAS diet (r = 0.77, P < 0.001) and had a higher R² value of 0.28 than did AS intake (R² = 0.36). TS excretion differed between LAS (0.226 ± 0.09 mg/d) and HAS (0.365 ± 0.16 mg/d) feeding periods (P < 0.001).Conclusions: Urinary sodium appears to be a valid biomarker for sodium intake in nonobese adolescents. Urinary nitrogen is associated with protein intake, but nitrogen excretion rates were less than previously reported for adults, possibly owing to adolescent growth rates. TS excretion reflects AS at 25% AS intake and was responsive to the change in AS intake. Thus, urinary biomarkers are promising objective indicators of dietary intake in adolescents, although larger-scale feeding trials are needed to confirm these findings. This trial was registered at clinicaltrials.gov as NCT02455388.

Biomarker-predicted sugars intake compared with self-reported measures in US Hispanics/Latinos: results from the HCHS/SOL SOLNAS study

OBJECTIVE

Measurement error in self-reported total sugars intake may obscure associations between sugars consumption and health outcomes, and the sum of 24 h urinary sucrose and fructose may serve as a predictive biomarker of total sugars intake.

DESIGN

The Study of Latinos: Nutrition & Physical Activity Assessment Study (SOLNAS) was an ancillary study to the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) cohort. Doubly labelled water and 24 h urinary sucrose and fructose were used as biomarkers of energy and sugars intake, respectively. Participants' diets were assessed by up to three 24 h recalls (88 % had two or more recalls). Procedures were repeated approximately 6 months after the initial visit among a subset of ninety-six participants.

SETTING

Four centres (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA) across the USA.

SUBJECTS

Men and women (n 477) aged 18-74 years.

RESULTS

The geometric mean of total sugars was 167·5 (95 % CI 154·4, 181·7) g/d for the biomarker-predicted and 90·6 (95 % CI 87·6, 93·6) g/d for the self-reported total sugars intake. Self-reported total sugars intake was not correlated with biomarker-predicted sugars intake (r=-0·06, P=0·20, n 450). Among the reliability sample (n 90), the reproducibility coefficient was 0·59 for biomarker-predicted and 0·20 for self-reported total sugars intake.

CONCLUSIONS

Possible explanations for the lack of association between biomarker-predicted and self-reported sugars intake include measurement error in self-reported diet, high intra-individual variability in sugars intake, and/or urinary sucrose and fructose may not be a suitable proxy for total sugars intake in this study population.

Association between sucrose intake and risk of overweight and obesity in a prospective sub-cohort of the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk)

OBJECTIVE

The objective of the present study was to investigate associations between sugar intake and overweight using dietary biomarkers in the Norfolk cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk).

DESIGN

Prospective cohort study.

SETTING

EPIC-Norfolk in the UK, recruitment between 1993 and 1997.

SUBJECTS

Men and women (n 1734) aged 39-77 years. Sucrose intake was assessed using 7 d diet diaries. Baseline spot urine samples were analysed for sucrose by GC-MS. Sucrose concentration adjusted by specific gravity was used as a biomarker for intake. Regression analyses were used to investigate associations between sucrose intake and risk of BMI>25·0 kg/m2 after three years of follow-up.

RESULTS

After three years of follow-up, mean BMI was 26·8 kg/m2. Self-reported sucrose intake was significantly positively associated with the biomarker. Associations between the biomarker and BMI were positive (β=0·25; 95 % CI 0·08, 0·43), while they were inverse when using self-reported dietary data (β=-1·40; 95 % CI -1·81, -0·99). The age- and sex-adjusted OR for BMI>25·0 kg/m2 in participants in the fifth v. first quintile was 1·54 (95 % CI 1·12, 2·12; P trend=0·003) when using biomarker and 0·56 (95 % CI 0·40, 0·77; P trend<0·001) with self-reported dietary data.

CONCLUSIONS

Our results suggest that sucrose measured by objective biomarker but not self-reported sucrose intake is positively associated with BMI. Future studies should consider the use of objective biomarkers of sucrose intake.

Urinary Sugars--A Biomarker of Total Sugars Intake

Measurement error in self-reported sugars intake may explain the lack of consistency in the epidemiologic evidence on the association between sugars and disease risk. This review describes the development and applications of a biomarker of sugars intake, informs its future use and recommends directions for future research. Recently, 24 h urinary sucrose and fructose were suggested as a predictive biomarker for total sugars intake, based on findings from three highly controlled feeding studies conducted in the United Kingdom. From this work, a calibration equation for the biomarker that provides an unbiased measure of sugars intake was generated that has since been used in two US-based studies with free-living individuals to assess measurement error in dietary self-reports and to develop regression calibration equations that could be used in future diet-disease analyses. Further applications of the biomarker include its use as a surrogate measure of intake in diet-disease association studies. Although this biomarker has great potential and exhibits favorable characteristics, available data come from a few controlled studies with limited sample sizes conducted in the UK. Larger feeding studies conducted in different populations are needed to further explore biomarker characteristics and stability of its biases, compare its performance, and generate a unique, or population-specific biomarker calibration equations to be applied in future studies. A validated sugars biomarker is critical for informed interpretation of sugars-disease association studies.

How effective are current dietary guidelines for cardiovascular disease prevention in healthy middle-aged and older men and women? A randomized controlled trial

BACKGROUND

Controversy surrounds the effectiveness of dietary guidelines for cardiovascular disease (CVD) prevention in healthy middle-aged and older men and women.

OBJECTIVE

The objective was to compare effects on vascular and lipid CVD risk factors of following the United Kingdom dietary guidelines with a traditional British diet (control).

DESIGN

With the use of a parallel-designed randomized controlled trial in 165 healthy nonsmoking men and women (aged 40-70 y), we measured ambulatory blood pressure (BP) on 5 occasions, vascular function, and CVD risk factors at baseline and during 12 wk after random assignment to treatment. The primary outcomes were differences between treatments in daytime ambulatory systolic BP, flow-mediated dilation, and total cholesterol/HDL cholesterol. Secondary outcomes were differences between treatment in carotid-to-femoral pulse wave velocity, high-sensitivity C-reactive protein, and a measure of insulin sensitivity (Revised Quantitative Insulin Sensitivity Check Index).

RESULTS

Data were available on 162 participants, and adherence to the dietary advice was confirmed from dietary records and biomarkers of compliance. In the dietary guidelines group (n = 80) compared with control (n = 82), daytime systolic BP was 4.2 mm Hg (95% CI: 1.7, 6.6 mm Hg; P < 0.001) lower, the treatment effect on flow-mediated dilation [-0.62% (95% CI: -1.48%, 0.24%)] was not significant, the total cholesterol:HDL cholesterol ratio was 0.13 (95% CI: 0, 0.26; P = 0.044) lower, pulse wave velocity was 0.29 m/s (95% CI: 0.07, 0.52 m/s; P = 0.011) lower, high-sensitivity C-reactive protein was 36% (95% CI: 7%, 48%; P = 0.017) lower, the treatment effect on the Revised Quantitative Insulin Sensitivity Check Index [2% (95% CI: -2%, 5%)] was not significant, and body weight was 1.9 kg (95% CI: 1.3, 2.5 kg; P < 0.001) lower. Causal mediated effects analysis based on urinary sodium excretion indicated that sodium reduction explained 2.4 mm Hg (95% CI: 1.0, 3.9 mm Hg) of the fall in blood pressure.

CONCLUSION

Selecting a diet consistent with current dietary guidelines lowers BP and lipids, which would be expected to reduce the risk of CVD by one-third in healthy middle-aged and older men and women. This study is registered at www.isrctn.com as 92382106.

Dietary biomarkers: advances, limitations and future directions

The subjective nature of self-reported dietary intake assessment methods presents numerous challenges to obtaining accurate dietary intake and nutritional status. This limitation can be overcome by the use of dietary biomarkers, which are able to objectively assess dietary consumption (or exposure) without the bias of self-reported dietary intake errors. The need for dietary biomarkers was addressed by the Institute of Medicine, who recognized the lack of nutritional biomarkers as a knowledge gap requiring future research. The purpose of this article is to review existing literature on currently available dietary biomarkers, including novel biomarkers of specific foods and dietary components, and assess the validity, reliability and sensitivity of the markers. This review revealed several biomarkers in need of additional validation research; research is also needed to produce sensitive, specific, cost-effective and noninvasive dietary biomarkers. The emerging field of metabolomics may help to advance the development of food/nutrient biomarkers, yet advances in food metabolome databases are needed. The availability of biomarkers that estimate intake of specific foods and dietary components could greatly enhance nutritional research targeting compliance to national recommendations as well as direct associations with disease outcomes. More research is necessary to refine existing biomarkers by accounting for confounding factors, to establish new indicators of specific food intake, and to develop techniques that are cost-effective, noninvasive, rapid and accurate measures of nutritional status.

Determination of sucrose in equine serum using liquid chromatography-mass spectrometry (LC/MS)

Mucosal integrity may be objectively assessed by determination of the absorption of exogenous substances such as sucrose. Gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) have been reported for the accurate quantification of low concentrations of sucrose in serum. LC/MS offered the advantage of high sensitivity and mass selectivity without the need for extensive sample derivatization required for GC/MS methods. However, the high polarity and non-volatile nature of the sucrose molecule renders LC/MS techniques challenging. Previously published reports lacked sufficient detail to permit replication of methodology. Problems encountered with existing protocols included poor peak resolution and weak fragmentation of the parent molecule. This communication describes a LC/MS protocol developed to provide improved resolution and product detection.

Urinary sucrose and fructose as biomarkers of sugar consumption: comparison of normal weight and obese volunteers

Using urinary sugars as a biomarker of consumption, we have previously shown that obese people consume significantly more sugars than individuals of normal weight. However, there is concern that recovery of this biomarker may differ between normal weight and obese individuals. A total of 19 subjects, divided into two groups according to their body mass index (BMI) (normal weight BMI < or = 25 kg/m(2), n=10; obese BMI > or = 30 kg/m(2), n=9), participated in a randomized crossover dietary intervention study of three diets providing 13, 30 and 50% of energy from sugars for 4 days each while living in a volunteer suite. The mean urinary sucrose and fructose excretions in 24-h urine increased with increasing sugar consumption over the three dietary periods in both BMI groups and were significantly different between the diets (P < 0.01). There was no significant interaction effect of BMI class on the mean urinary excretions of these sugars with different sugar intakes, either as absolute values or expressed as a percentage of total sugar intake. In conclusion, BMI does not affect the validity of sucrose and fructose excretions in 24-h urine collections used as biomarkers to estimate total sugar consumption.