Feasibility, Acceptability, and Preliminary Validity of Self-Report Dietary Assessment in Adults with Multiple Sclerosis: Comparison with Doubly Labeled Water Measured Total Energy Expenditure.

BACKGROUND: Diet is a modifiable behavior of interest in multiple sclerosis (MS); however, measures of diet in persons with MS have not been vetted for feasibility, acceptability, and validity. METHODS: This cross-sectional study examined the Automated Self-Administered 24-H (ASA24) Dietary Assessment Tool in 30 persons with MS and 15 healthy control (HC) participants. Participants were prompted to complete six ASA24 recalls and undergo a standard doubly labeled water (DLW) protocol. Acceptability of ASA24 was assessed using an online questionnaire. Total energy expenditure (TEE) from DLW was compared with ASA24-reported energy intake for assessing validity. RESULTS: All participants completed four or more ASA24 recalls, indicating feasibility of ASA24. Regarding acceptability, the hardest part of completing the ASA24 was remembering everything eaten the previous day. Pearson correlation coefficients between DLW TEE and ASA24 kcal/day were not significant among HC (r = 0.40; p = 0.14) or MS (r = 0.26; p = 0.16) participants. The absolute mean error between DLW TEE and ASA24 among HC participants was 694.96 ± 506.25 mean kcal/day and among MS participants was 585.37 ± 529.02 mean kcal/day; this represents a mean difference of 30 and 25%, respectively. CONCLUSION: This study established the feasibility and acceptability of ASA24 in persons with MS and provides a foundation regarding the need for further validation research examining appropriate outcomes for supporting dietary interventions.

Comparing saliva and urine samples for measuring breast milk intake with the 2H oxide dose-to-mother technique among children 2-4 months old.

Saliva and urine are the two main body fluids sampled when breast milk intake is measured with the 2H oxide dose-to-mother technique. However, these two body fluids may generate different estimates of breast milk intake due to differences in isotope enrichment. Therefore, we aimed to assess how the estimated amount of breast milk intake differs when based on saliva and urine samples and to explore whether the total energy expenditure of the mothers is related to breast milk output. We used a convenience sample of thirteen pairs of mothers and babies aged 2-4 months, who were exclusively breastfed and apparently healthy. To assess breast milk intake, we administered doubly labelled water to the mothers and collected saliva samples from them, while simultaneously collecting both saliva and urine from their babies over a 14-d period. Isotope ratio MS was used to analyse the samples for 2H and 18O enrichments. Mean breast milk intake based on saliva samples was significantly higher than that based on urine samples (854·5 v. 812·8 g/d, P = 0·029). This can be attributed to slightly higher isotope enrichments in saliva and to a poorer model fit for urine samples as indicated by a higher square root of the mean square error (14·6 v. 10·4 mg/kg, P = 0·001). Maternal energy expenditure was not correlated with breast milk output. Our study suggests that saliva sampling generates slightly higher estimates of breast milk intake and is more precise as compared with urine and that maternal energy expenditure does not influence breast milk output.

Guidelines for the Use of Deuterium Oxide (D2O) in 1H NMR Metabolomics.

In metabolomics, nuclear magnetic resonance (NMR) spectroscopy allows to identify and quantify compounds in biological samples. The sample preparation generally requires only few steps; however, an indispensable factor is the addition of a locking substance into the biofluid sample, such as deuterium oxide (D2O). While creatinine loss in pure D2O is well-described, the effects of different D2O concentrations on the signal profile of biological samples are unknown. In this work, we investigated the effect of D2O levels in the NMR buffer system in urine samples, in dependence on dwell time and temperature exposition. We reveal a decrease of the urinary creatinine peak area up to 35% after 24 h of dwell time at room temperature (RT) using 25% (v/v) D2O, but only 4% loss using 2.5% D2O. 1H, inverse-gated (IG) 13C, DEPT-HSQC NMR, and mass spectrometry (MS) experiments confirmed a proton-deuterium (H/D) exchange at the CH2. This leads to underestimation of creatinine levels and has an extensive effect when creatinine is used for normalization. This work offers a sample stability examination, depending on the D2O concentration, dwell time, and temperature and enables a method to correct for the successive loss. We propose an equation to correct the creatinine loss for samples prepared with various D2O concentrations and storage temperatures for dwell times up to 24 h. The correction function was validated against an external data set with n = 26 samples. To ensure sufficient creatinine stability in future studies, we suggest that a maximum of 10% D2O should be used at 4 °C or 2.5% D2O at RT, respectively.

Comparison of estimated energy requirements using predictive equations with total energy expenditure measured by the doubly labelled water method in acute spinal cord injury.

STUDY DESIGN: Prospective, observational OBJECTIVES: To evaluate agreement between a reference method (doubly labelled water, DLW) of total energy expenditure (TEE) and published equations for estimating energy requirements in acute spinal cord injury (SCI). SETTING: Victoria, Australia METHODS: Twenty participants (18 male) within 8 weeks of traumatic SCI completed DLW, anthropometric and dietary intake assessments. Energy requirements were predicted using Harris-Benedict, Schofield, Henry, Nelson, Buchholz and Chun equations, multiplied by a combined activity and stress factor of 1.3, and the ratio method (kJ/kg body weight). Fat-free mass (FFM) and fat mass (FM) were calculated from TBW-derived DLW and from bioelectrical impedance spectroscopy (BIS). RESULTS: Median time since injury was 41 days. Median TEE was 9.1 MJ. Fair agreement was found between TEE and predicted energy requirements for the Chun (rc = 0.39), the Harris-Benedict equation (rc = 0.30), the ratio method (rc = 0.23) and the Buchholz (rc = 0.31) and Nelson equations (rc = 0.35), which incorporate measures of FFM and/or FM. Other equations showed weak concordance with DLW. When two hypermetabolic patients were removed, agreement between TEE and predicted energy requirements using the Buchholz equation increased to substantial (rc = 0.72) and using the Nelson (rc = 0.53) and Chun equations (rc = 0.53) increased to moderate. The Buchholz equation had the smallest limits of agreement (-2.4-2.3 MJ/d). CONCLUSION: The population-specific Buchholz equation that incorporates FFM, predicted from either BIS or DLW, demonstrated the best agreement in patients with acute SCI. SPONSORSHIP: The study was funded by grants from the Institute for Safety, Compensation and Recovery Research (ISCRR Project # NGE-E-13-078) and Austin Medical Research Foundation. M Panisset was supported by an Australian Postgraduate Award.

The Deuterium Oxide-to-the-Mother Method Documents Adequate Breast-Milk Intake among Sri Lankan Infants.

BACKGROUND: The WHO recommends that exclusive breastfeeding should last up to 6 mo. However, human milk intake of Sri Lankan infants has not been quantified scientifically. OBJECTIVES: The objectives of this study were to measure the human milk intake of Sri Lankan infants during the first 6 mo of age and to document the breastfeeding practices of their mothers. METHODS: Forty-eight healthy mother-infant dyads were randomly recruited for this cross-sectional study at well-baby clinics. Milk intake was measured using the deuterium oxide-to-the-mother technique over a period of 2 wk. Information on breastfeeding practice and living standards of the participants were gathered using an interviewer-administered questionnaire. RESULTS: Human milk intake was 672 ± 123 g ⋅ d(-1) (mean ± SD), 776 ± 212 g ⋅ d(-1), and 801 ± 51 g ⋅ d(-1) for infants <2 mo, 2 to <4 mo, and 4-6 mo of age, respectively. The milk intakes were not different among the age groups. Maternal body composition, age, or parity had no effects on milk intake of the infants. However, mother's education : P < 0.05, r = 0.35), infant's age (P < 0.05, r = 0.30), and body mass index (P < 0.05, r = 0.41 : positively correlated with the milk intake. Over 63% of mothers had commenced breastfeeding within 30 min of delivery. About 60% of the mothers were feeding the baby 6-10 times during the daytime and >81% intended to continue exclusive breastfeeding until 6 mo of age. CONCLUSION: This study, for the first time, documented the adequacy of breast-milk intake among Sri Lankan infants and the nutrition status of the mothers.

Energy expenditure by multisensor armband in overweight and obese lactating women validated by doubly labeled water.

OBJECTIVE: To validate total energy expenditure (TEE) and activity energy expenditure (AEE) from the portable SenseWear armband (SWA) Pro 2 (TEESWA and AEESWA ; InnerView software versions SWA 5.1 and SWA 6.1) against TEE from doubly labeled water (DLW) and AEE from DLW and indirect calorimetry (TEEDLW and AEEDLW ) in overweight/obese lactating women at 10 weeks postpartum. DESIGN AND METHODS: TEE was measured simultaneously with DLW (14 days) and SWA (first 7 days). Lactating women (n = 62), non-smoking, with a BMI > 25 kg/m(2) and wearing time SWA ≥ 90% were included. RESULTS: Mean TEESWA5.1 was overestimated with 85 kcal/day compared to TEEDLW (P = 0.040), while mean TEESWA6.1 was underestimated with 241 kcal/day compared to TEEDLW (P < 0.001). Mean AEESWA5.1 was similar to mean AEEDLW (P = 0.818), while mean AEESWA6.1 was underestimated with 581 kcal/day compared to AEEDLW (P < 0.001). TEESWA6.1 and AEESWA6.1 were systematically underestimated at higher levels of energy expenditure and BMI while only AEESWA5.1 was systematically overestimated at higher levels of energy expenditure. CONCLUSIONS: TEESWA5.1 and AEESWA5.1 were fairly estimated on a group level while TEESWA6.1 and AEESWA6.1 were significantly and systematically underestimated. Both SWA software versions showed large individual variation in agreement with TEEDLW and AEEDLW , limiting the validity on individual level.

Change in body mass accurately and reliably predicts change in body water after endurance exercise.

This study tested the hypothesis that the change in body mass (DeltaBM) accurately reflects the change in total body water (DeltaTBW) after prolonged exercise. Subjects (4 men, 4 women; 22-36 year; 66 +/- 10 kg) completed 2 h of interval running (70% VO(2max)) in the heat (30 degrees C), followed by a run to exhaustion (85% VO(2max)), and then sat for a 1 h recovery period. During exercise and recovery, subjects drank fluid or no fluid to maintain their BM, increase BM by 2%, or decrease BM by 2 or 4% in separate trials. Pre- and post-experiment TBW were determined using the deuterium oxide (D(2)O) dilution technique and corrected for D(2)O lost in urine, sweat, breath vapor, and nonaqueous hydrogen exchange. The average difference between DeltaBM and DeltaTBW was 0.07 +/- 1.07 kg (paired t test, P = 0.29). The slope and intercept of the relation between DeltaBM and DeltaTBW were not significantly different from 1 and 0, respectively. The intraclass correlation coefficient between DeltaBM and DeltaTBW was 0.76, which is indicative of excellent reliability between methods. Measuring pre- to post-exercise DeltaBM is an accurate and reliable method to assess the DeltaTBW.

Daily fluid turnover during preseason training in U.S. college football.

The authors measured 24-h fluid-turnover (FTO) rate during 6 d of preseason training in U.S. college football players. Players, training (T, n = 9, full gear and contact drills) and reference (R, n = 4, conditioning without gear or contact), ingested a deuterium oxide (D(2)O) dose and provided urine samples every 24 h for analysis of D(2)O. During one approximately 2.3-h practice (wet-bulb globe temperature 24.6 degrees C), body-mass change, urine production, and voluntary fluid intake were measured to calculate gross sweat loss (GSL). Average FTO was 10.3 +/- 2.2 L/d for T and 7.0 +/- 1.0 L/d for R. GSL was 3.4 +/- 1.5 L for T and 1.7 +/- 1.3 for R (P > 0.05). By Day 6, body mass decreased significantly in T (-2.4 +/- 1.3 kg, P < 0.05) but not in R (0.38 +/- 0.95 kg). With preseason training under moderate environmental stress, football players had high FTO and sweat rates, which might have contributed to a loss of body mass during preseason football training.

Assessment of body composition and breast milk volume in lactating mothers in pastoral communities in Pokot, Kenya, using deuterium oxide.

BACKGROUND: In sub-Saharan Africa, the practice of breast-feeding infants is common. Records documenting the intake of breast milk amongst infants are limited. This study evaluated the association between maternal body composition and the intake of breast milk in infants from the pastoral communities within Pokot, Kenya. METHODS: The study was conducted in 10 lactating mothers who were participating in a longitudinal study aimed at determining maternal body composition, iron stores and vitamin A status during the third trimester pregnancy and four months after they had given birth. Maternal and infant anthropometric measurements were made, and maternal blood samples were taken to determine serum retinol and ferritin levels. Infant milk intake and maternal fat-free mass (FFM) and percent body fat (% BF) were measured using 'the dose to the mother method'. A measured deuterium oxide ((2)H(2)O) dose was given to the mother. Urine and breast milk from the mother, and saliva samples from the infant, were collected on days 1, 8 and 14 after dosing. RESULTS: The mean (+/- SD) maternal mid upper arm circumference (MUAC) and body mass index (BMI) were 21.8 (0.9) cm and 18.6 (1.0) kg/height (m(2)), respectively. Infant weight and weight/age Z score were 4.956 (0.874) kg and -1.750 (0.77), respectively. Throughout the study, the infants gained 20 (4) g/day in body weight and had a milk intake of 555 (22) ml/day. The energy intake of the infant was 1,602 (148) kJ/day and was lower (p < 0.05) than the 2,404 (423) kJ/day estimated requirement by the FAO/WHO/UNU. The maternal FFM, %BF, Hb, Hct, ferritin and retinol were 32.8 (3.1) kg, 17.24 (7.0), 11.5 (1.3) g/dl, 33.9 (4.9), 16.2 (0.1) microg/l and 0.894 (0.16) micromol/l, respectively. Infant milk intake was significantly and positively correlated to maternal pregnancy triceps (r = 0.679) p < 0.05) and pregnancy MUAC (r = 0.725) p < 0.05). Maternal pregnancy MUAC was an important predictor of infant breast milk intake. CONCLUSION: Data on volume of breast milk consumed by the infants suggests, at least for this group of infants, that adequate growth may not be achieved. There is a possibility that lactating mothers practicing exclusive breast-feeding and living under harsh conditions may experience periods of low breast milk volume. Body composition and biochemical findings among this group of Pokot mothers indicate dietary inadequacies that require nutritional intervention.

Using intake biomarkers to evaluate the extent of dietary misreporting in a large sample of adults: the OPEN study.

This paper describes the Observing Protein and Energy Nutrition (OPEN) Study, conducted from September 1999 to March 2000. The purpose of the study was to assess dietary measurement error using two self-reported dietary instruments-the food frequency questionnaire (FFQ) and the 24-hour dietary recall (24HR)-and unbiased biomarkers of energy and protein intakes: doubly labeled water and urinary nitrogen. Participants were 484 men and women aged 40-69 years from Montgomery County, Maryland. Nine percent of men and 7% of women were defined as underreporters of both energy and protein intake on 24HRs; for FFQs, the comparable values were 35% for men and 23% for women. On average, men underreported energy intake compared with total energy expenditure by 12-14% on 24HRs and 31-36% on FFQs and underreported protein intake compared with a protein biomarker by 11-12% on 24HRs and 30-34% on FFQs. Women underreported energy intake on 24HRs by 16-20% and on FFQs by 34-38% and underreported protein intake by 11-15% on 24HRs and 27-32% on FFQs. There was little underreporting of the percentage of energy from protein for men or women. These findings have important implications for nutritional epidemiology and dietary surveillance.

Structure of dietary measurement error: results of the OPEN biomarker study.

Multiple-day food records or 24-hour dietary recalls (24HRs) are commonly used as "reference" instruments to calibrate food frequency questionnaires (FFQs) and to adjust findings from nutritional epidemiologic studies for measurement error. Correct adjustment requires that the errors in the adopted reference instrument be independent of those in the FFQ and of true intake. The authors report data from the Observing Protein and Energy Nutrition (OPEN) Study, conducted from September 1999 to March 2000, in which valid reference biomarkers for energy (doubly labeled water) and protein (urinary nitrogen), together with a FFQ and 24HR, were observed in 484 healthy volunteers from Montgomery County, Maryland. Accounting for the reference biomarkers, the data suggest that the FFQ leads to severe attenuation in estimated disease relative risks for absolute protein or energy intake (a true relative risk of 2 would appear as 1.1 or smaller). For protein adjusted for energy intake by using either nutrient density or nutrient residuals, the attenuation is less severe (a relative risk of 2 would appear as approximately 1.3), lending weight to the use of energy adjustment. Using the 24HR as a reference instrument can seriously underestimate true attenuation (up to 60% for energy-adjusted protein). Results suggest that the interpretation of findings from FFQ-based epidemiologic studies of diet-disease associations needs to be reevaluated.

Quantifying tracer levels of (2)H(2)O enrichment from microliter amounts of plasma and urine by (2)H NMR.

A simple and sensitive (2)H NMR measurement of (2)H(2)O enrichment from a 10 microl volume of body fluid is presented. The method allows (2)H-enrichment levels of 0.1% or above to be rapidly determined from 10 microl of plasma or urine. The measurement is insensitive to the presence of plasma protein, allowing direct analysis of (2)H(2)O enrichment from native plasma samples. Magn Reson Med 45:156-158, 2001.

Rapid measurement of deuterium content of breath following oral ingestion to determine body water.

The ability to measure total body water accurately, non-invasively and rapidly with results that are immediately available would represent an important advance in body composition research. Flowing afterglow mass spectrometry (FA-MS) has been developed to enable immediate measurement of deuterium content in breath water from single exhalations, which when combined with oral D2O loading enables measurement of total body water. We report here its first use in normal subjects, demonstrating the dispersal kinetics of deuterium in the body by monitoring deuterium in breath water following ingestion. Ten studies were performed in six normal subjects. After obtaining baseline samples, each subject ingested 0.3 g x kg(-1) of 99.9% pure D2O. Subsequently, breath samples were obtained every 3-5 minutes until equilibration had occurred. Three distinct phases in breath deuterium content were observed: an initial immediate peak due to HDO remaining in the oral cavity, a secondary peak reflecting gastrointestinal absorption and finally equilibration with the body water. The incremental increase in breath deuterium abundance between baseline and equilibration was used to calculate the total body water. Mathematical fitting of this final equilibration phase demonstrated that the measured deuterium abundance was within 0.2% of the ideal (asymptotic) value within 2 hours in all cases. We conclude that FA-MS is a powerful new method that, when combined with oral D2O loading, enables measurement of the dispersal kinetics of HDO and the calculation of total body water within 2 hours.

Energy requirements in Chilean infants.

AIM: To evaluate the energy requirements of breast fed infants. METHODS: The study was conducted in 17 healthy exclusively breast fed infants of normal birth weight (mean (SD) 3332 (280) g). Energy expenditure by the doubly labelled water method and milk intake by the dose to infant method were measured at 34 (4) days. A dose of 0. 2 g/kg deuterium oxide (99.8%) and 2.0 g/kg 10% (18)O labelled water was given to the infants, and urine samples were collected for seven consecutive days after dosing. RESULTS: The mean (SD) weight of the infants during the period of evaluation was 4617 (343) g and weight gain 34.0 (7.5) g/day. Daily milk intake was 728 (101) g and its metabolisable energy content 2.71 kJ/g. The energy expenditure of the infants was 1205 (312) kJ/day and energy required for growth was 607 (130) kJ/day. When combined this produced an energy requirement of 391 kJ/kg/day for these infants. CONCLUSION: These data agree with those from other studies in the United Kingdom and the United States and suggest that adequate growth can be achieved with 19.4% less energy than recommended by FAO/WHO/UNU.

Validation of a self-administered food-frequency questionnaire administered in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study: comparison of energy, protein, and macronutrient intakes estimated with the doubly labeled water, urinary nitrogen, and repeated 24-h dietary recall methods.

BACKGROUND: The validation of dietary assessment instruments is critical in the evaluation of diet as a chronic disease risk factor. OBJECTIVE: The objective was to assess the validity of a self-administered food-frequency questionnaire by comparison with dietary recall, urinary nitrogen excretion, and total energy expenditure data. DESIGN: Over a 1-y period, data from twelve 24-h dietary recalls, a food-frequency questionnaire, and four 24-h urine samples were obtained from 134 study participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study in Potsdam, Germany. In a substudy of 28 participants, total energy expenditure from doubly labeled water measurements was assessed. RESULTS: Energy-adjusted, deattenuated correlation coefficients between the questionnaire and the recalls ranged from 0.54 for dietary fiber to 0.86 for alcohol. Cross-classification of quintiles of nutrient intakes from the questionnaire and recalls indicated severe misclassification to be <4%. Reported protein intake correlated with estimated protein excretion (r = 0.46). Energy intake and total energy expenditure were also significantly correlated (r = 0.48); however, all but one subject underreported their energy intake. The magnitude of underreporting varied considerably, by 22% on average, and increased slightly with increasing energy intake. A similar pattern of underreporting was observed when energy intakes from the 24-h dietary recalls were compared with total energy expenditure. CONCLUSIONS: These data indicate an acceptable relative validity of the food-frequency questionnaire in this study population. Compared with measurements of total energy expenditure and protein excretion, however, only moderate agreement with both the food-frequency questionnaire and the 24-h dietary recalls was observed.

The use of infrared spectrophotometry for measuring body water spaces.

BACKGROUND: The conventional method of measuring total body water by the deuterium isotope dilution method uses gas isotope ratio mass spectrometry (IRMS), which is both expensive and time-consuming. We investigated an alternative method, using Fourier transform infrared spectrophotometry (FTIR), which uses less expensive instrumentation and requires little sample preparation. METHOD: Total body water measurements in human subjects were made by obtaining plasma, saliva, and urine samples before and after oral dosing with 1.5 mol of deuterium oxide. The enrichments of the body fluids were determined from the FTIR spectra in the range 1800-2800 cm-1, using a novel algorithm for estimation of instrumental response, and by IRMS for comparison. RESULTS: The CV (n = 5) for repeat determinations of deuterium oxide in biological fluids and calibrator solutions (400-1000 micromol/mol) was found to be in the range 0.1-0.9%. The use of the novel algorithm instead of the integration routines supplied with the instrument gave at least a threefold increase in precision, and there was no significant difference between the results obtained with FTIR and those obtained with IRMS. CONCLUSION: This improved infrared method for measuring deuterium enrichment in plasma and saliva requires no sample preparation, is rapid, and has potential value to the clinician.

Assay of the deuterium enrichment of water via acetylene.

A technique is presented for measuring the 2H enrichment of water in biological samples when this enrichment is greater than 0.2%. The sample is reacted with calcium carbide to form acetylene gas, which is determined by gas chromatography electron impact ionization mass spectrometry. Ion-molecule reactions, resulting in proton abstraction, are minimized by lowering the electron ionization energy from the usual 70 eV to 45 eV. This technique is much more rapid and economical than the classical isotope ratio mass spectrometric assay of the enrichment of hydrogen gas derived from reduction of water.

Calculation of total body water in infancy.

OBJECTIVE: Total body water can be calculated using stable isotopes by two alternative approaches known as the plateau method and the back extrapolation method. These methods treat the isotopic data in different ways and consequently do not necessarily produce identical values for total body water. Total body water was therefore calculated using both methods using two different tracers, 2H and 18O. DESIGN: A cohort of infants was studied at three ages in the first year of life, and the two methods and two tracers compared at each age. RESULTS: The plateau method was found to produce values for total body water greater than those obtained by the back extrapolation method at all three ages using both isotopes (P < 0.01 in all cases). CONCLUSIONS: This difference is due to the different time points at which total body water is calculated. Back extrapolation values correspond more closely to values of total body water obtained by alternative techniques.