Between-person Variability Research Articles

Mindfulness practice predicts interleukin-6 responses to a mindfulness-based alcohol relapse prevention intervention

Chronic alcohol misuse can result in chronically elevated interleukin (IL)-6, a pro-inflammatory cytokine, in the bloodstream. Given that Mindfulness-Based Relapse Prevention (MBRP) has been shown to reduce alcohol misuse, MBRP might also be effective in reducing IL-6 concentrations. Past research has found, however, that IL-6 does not respond consistently to mindfulness-based interventions. Building on prior studies, we examined whether between-person variability in engagement with mindfulness training (i.e., formal mindfulness practice time) is associated with between-person variability in changes in serum IL-6, using data from a randomized controlled trial evaluating MBRP for Alcohol Dependence (MBRP-A). Participants were 72 alcohol dependent adults (mean age = 43.4 years, 63.9% male, 93.1% White) who received a minimum dose (i.e., at least four sessions) of MBRP-A either at the start of the trial (n = 46) or after a 26-week delay (n = 26). IL-6 concentrations did not significantly change from pre- to post-intervention for the full sample. Nevertheless, greater mindfulness practice time was significantly associated with reduced IL-6 levels (r = −0.27). The association between practice time and IL-6 changes remained significant when controlling for intervention timing (i.e., immediate or after the 26-week delay), demographic characteristics, and changes in mindful awareness, obsessive-compulsive drinking, and depressive symptoms. The association between practice time and IL-6 changes was not significant when omitting the minimum treatment dose requirement. Overall, results suggest that the level of engagement in mindfulness training may predict changes in the inflammatory pathophysiology in adults with alcohol dependence.

Comparison of seasonal serum 25-hydroxyvitamin D concentrations among pregnant women in Mongolia and Boston

Adequate vitamin D status during pregnancy is important for developing fetal bone strength and density and may play a role in preventing a range of skeletal and non-skeletal diseases in both mothers and children. We previously identified Mongolian women of reproductive age to have the lowest vitamin D levels yet observed in any population globally, which renders this population uniquely important in vitamin D research. In this study, we measured the seasonal distribution of 25-hydroxyvitamin D (25(OH)D) concentration in 390 healthy third trimester pregnant women living in urban and rural Mongolia using DiaSorin LIAISON and compared this distribution to that of 206 third trimester women living in Boston, USA. Also, we analyzed seasonally-independent associations between (25(OH)D) levels and selected predictors in both groups using quantile regression. Mean 25(OH)D levels were significantly higher and less seasonal in Boston (seasonal range: 27.1 ± 7.0–31.5 ± 7.7 ng/ml) than in Mongolia (seasonal range: 11.2 ± 3.9–19.2 ± 6.7 ng/ml). Adjusting for month of blood draw, higher 25(OH)D levels were significantly associated with older age, lower gravidity, lower BMI, and lack of a college or university degree among Boston participants, however, only gravidity was robust to multivariable adjustment. No assessed characteristics were independently predictive in Mongolia, likely due to universally low 25(OH)D levels and a resulting lack of between-person variation. In conclusion, vitamin D status among pregnant Mongolians is severely depressed throughout the year and should be addressed through fortification and supplementation, while in the U.S., deficiency is associated with specific characteristics targetable through supplementation.

A Novel Hierarchical LATER Process Model: Evaluating Latent Sources of Variation in Reaction Times of Adult Daily Smokers.

Reaction time data from cognitive tasks continue to be a key way to assess decision-making in various contexts to better understand addiction. The goal of this paper is twofold: to introduce a nuanced modeling approach for reaction time data and to demonstrate the novel insights it can provide into the decision processes of nicotine-dependent individuals in different contexts. We focus on the Linear Approach to Threshold with Ergodic Rate (LATER) model, which is a cognitive process model that describes reaction time data in terms of two distinct aspects of cognitive functioning: speed of information accumulation (“accretion”) and threshold amount of information needed prior to execution (“caution”). We introduce a novel hierarchical extension to the LATER model to simultaneously account for differences across persons and experimental conditions, both in the accretion and caution parameters. This approach allows for the inclusion of person-specific predictor variables to explain between-person variation in terms of accretion and caution together with condition-specific predictors to model experimental condition manipulations. To highlight the usefulness of this model, we analyze reaction time data from a study on adult daily cigarette smokers. Participants performed a monetary incentivized Go/No-Go task during two testing sessions, once while following their typical smoking patterns and again following 12 h of verified smoking abstinence. Our main results suggest that regardless of trial type, smokers in a period of abstinence have faster accretion rates, and lower caution thresholds relative to smoking as usual.

Variability in body temperature in healthy adults and in patients receiving chemotherapy: prospective observational cohort study

Between-individual variability of body temperature has been little investigated, but is of clinical importance: for example, in detection of neutropenic sepsis during chemotherapy. We studied within-person and between-person variability in temperature in healthy adults and those receiving chemotherapy using a prospective observational design involving 29 healthy participants and 23 patients undergoing chemotherapy. Primary outcome was oral temperature. We calculated each patient’s mean temperature, standard deviation within each patient (within-person variability), and between patients (between-person variability). Secondary analysis explored temperature changes in the three days before admission for neutropenic sepsis. 1,755 temperature readings were returned by healthy participants and 1,765 by chemotherapy patients. Mean participant temperature was 36.16 C (95% CI 36.07–36.26) in healthy participants and 36.32 C (95% CI 36.18–36.46) in chemotherapy patients. Healthy participant within-person variability was 0.40 C (95% CI 0.36–0.44) and between-person variability was 0.26 C (95% CI 0.16–0.35). Chemotherapy patient within-person variability was 0.39 C (95% CI 0.34–0.44) and between-person variability was 0.34 C (95% CI 0.26–0.48). Thus, use of a population mean rather than personalised baselines is probably sufficient for most clinical purposes as between-person variability is not large compared to within-person variability. Standardised guidance and provision of thermometers to patients might help to improve recording and guide management.

Abstract 3320: Dietary inflammatory potential in relation to the gut microbiome among persons at varied risk of colorectal neoplasia

Abstract Purpose: Diet modulates gut microbiome composition and systemic inflammation—both intermediary factors in the development of colorectal neoplasia. We investigated the association of total dietary inflammatory potential, as assessed by the literature-derived dietary inflammatory index (DII®), with gut microbiota diversity and composition, microbial gene pathways, and circulating markers. Methods: This epidemiological study was comprised of 36 cancer-free colonoscopy patients (79% positive for precancerous polyps) and 65 healthy volunteers from the medical center community (N=101). Participants completed dietary assessments and provided stool samples for 16S rDNA sequencing >1 month after colonoscopy/polyp removal or antibiotic use. In a subset (n=47), we conducted whole genome shotgun (WGS) sequencing and collected a fasting blood sample. Energy-adjusted (E)-DII score was calculated for each subject and categorized into tertiles. The association between E-DII and fecal microbiota alpha- and beta-diversity was examined. Linear discriminant analysis Effect Size (LEfSe) was used to identify differentially abundant taxa by E-DII level. Multiple linear regression models were used to examine associations controlled for confounders. Results from the least absolute shrinkage and selection operator (LASSO) method and Spearman’s correlation were used to select and evaluate associations of bacterial species with E-DII, their functional pathways, and circulating markers. Results: We observed large between-person variation in Bacteroidaceae and Enterobacteriaceae, two dominant bacteria in the overall sample. Neither alpha- nor beta-diversity significantly differed across E-DII levels. Ruminococcus torques, Acidaminococcus intestine, and Clostridium leptum were most abundant in the most pro-inflammatory diet group, while Akkermansia muciniphila was enriched among subjects with the most anti-inflammatory diet. In the WGS subset, Luteimonas mephitis was inversely associated with E-DII, circulating Lipocalin-2 (r=-0.34; P=0.02), and plasminogen activator inhibitor-1 (r=-0.29; P=0.05). Akkermansia muciniphilaappeared to be inversely correlated with monocyte chemoattractant protein-1 (r=-0.26; P=0.09). Two microbial pathways inversely associated with E-DII, AMP-activated protein kinase (AMPK) and carbon metabolism, were also inversely correlated with C-peptide (AMPK: r=-0.35, P= 0.02; carbon: r=-0.30, P=0.04). Conclusions: Dietary inflammatory potential was associated with differential composition of specific microbes, but not overall diversity of the gut microbiome. Species associated with E-DII were similarly associated with circulating inflammatory biomarkers. Microbial AMPK signaling and carbon metabolism pathways may underlie diet-microbiota interactions that modulate systemic inflammation. Citation Format: Jiali Zheng, Kristi L. Hoffman, Nitin Shivappa, Jonathan Busquets, Jiun-Sheng Chen, Samir Hanash, Susan Schembre, James Hébert, Joseph Petrosino, Peng Wei, Carrie R. Daniel. Dietary inflammatory potential in relation to the gut microbiome among persons at varied risk of colorectal neoplasia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3320.

Making a choice when information is missing: The case of medical versus consumer choices

This paper reports an experimental investigation of decision-making under uncertainty. Today, patients are encouraged to participate, or even decide for themselves what kind of care and treatment they should get; they are now in the position of a consumer that chooses what he believes is best. However, choosing a specific treatment rather than another has more important consequences in one's life than choosing a brand of yogurt rather than another. We wanted to see if people choose according to the available information, or not. Using a within-person design, we asked if there are any differences in the way people make medical choices, as compared to non-medical, neutral choices. Latency was also measured for the 21 choices each participant had to make. Additionally, we investigated moral purity, and gender – as between-person variables, to see if they play a role in decision-making under uncertainty. We analyzed the data with hierarchical linear modelling, where a series of choices (level 1) were nested within individuals (level 2). Results showed that people relied on the available information more often for medical choices than for non-medical, neutral choices. The less time spent, the higher the probability of relying on the available information. Also, while moral purity was not a significant predictor of decision-making, gender seems to be a moderator: men tend to rely more than women on the known information, in the case of medical choices, while in the case of non-medical choices, the differences between men and women are insignificant.

Separating within-person from between-person effects in the longitudinal co-occurrence of depression and different anxiety syndromes in youth

Cross-lagged panel models (CLPM) are often used to study anxiety-depression co-occurrence. However, the CLPM aggregates within- and between-person variance, which can lead to incorrect estimates. The latent curve model with structured residuals (LCM-SR) parses these sources of variance. We utilized the LCM-SR to examine prospective associations between anxiety (physical, social, separation) and depression. Youth (N = 680; Mage = 11.8; 55% female) completed measures of depression and anxiety every 3 months for 3 years (13 timepoints). The LCM-SR describing anxiety-depression co-occurrence fit well (RMSEA = 0.05, SRMR = 0.06). Depression predicted within-person change in social (b = 0.09), physical (b = 0.04), and separation anxiety (b = 0.06) over 13 timepoints. Separation anxiety predicted within-person change in depression (b = 0.08); social and physical anxiety did not. Findings advance knowledge of within-person development of anxiety-depression co-occurrence.

035 Variations in the Agreement between Subjective and Physiological Sexual Arousal among Women With and Without Sexual Dysfunction: The Moderating Role of Interoception

The present study examined the agreement (i.e., concordance) between subjective and physiological sexual arousal in women and explored how this varies as a function of sexual function and interoception. Sexually healthy women (n = 34) and women with sexual arousal concerns (n = 33) participated in this study. In a laboratory setting, women’s physiological and subjective sexual arousal were continuously measured in response to an erotic film. Physiological arousal was measured with a vaginal photoplethysmograph, and subjective sexual arousal was measured with an arousometer. Facets of interoception were assessed with the Multidimensional Assessment of Interoceptive Awareness (Mehling et al., 2011). Moderated growth curve modelling was used to assess the interrelatedness of these variables. A significant relationship between physiological and subjective sexual arousal that was somewhat stronger for sexually healthy women emerged, in addition to tremendous between-person variability for both groups. Several aspects of interoception moderated concordance rates, and this pattern varied across groups. High scores on the noticing subscale were linked with weaker concordance for women with sexual arousal concerns (β = -0.05, t = -3.35, p = 0.0008), yet no effect was seen for sexually healthy women. A negative effect of the not distracting (β =-0.14, t = -10.56, p < 0.001) and not worrying (β = -0.33, t = -12.36, p < 0.001) subscales on concordance emerged for sexually healthy women, but positive effects were found for women with sexual arousal concerns (β = 0.037, t =2.85, p = 0.004, and β = 0.10, t = 4.60, p < 0.001, respectively). Conversely, the emotional awareness (β = 0.06, t = 3.85, p < 0.001) and self-regulation (β = 0.07, t = 4.78, p < 0.001) subscales were positively related to concordance in sexually healthy women, whereas emotional awareness (β = -0.03, t = -2.09, p = 0.036) was negatively indicated in women with sexual arousal concerns.

Treatment engagement in a prison-based Therapeutic Community: A mixed-methods approach

Given the high proportion of inmates with histories of substance use disorders in the era of mass incarceration, many correctional institutions have integrated the prison-based Therapeutic Community (TC) into their programming. While most evaluations provide evidence of lowered rates of relapse and recidivism, the majority of TC graduates still have negative outcomes post-release. Filling an important gap in the TC treatment literature, we analyze quantitative measures of treatment engagement alongside qualitative narratives from prison-based TC residents, providing an essential look into the black box of TC treatment mechanisms. Quantitative results show more between-person variation than within-person change, reflecting trivial increases in treatment engagement throughout time in the program. Qualitative results unpack these findings, pointing to processes of selection bias, heterogeneous treatment effects, and program fidelity lapses. In combination, our mixed data identify tangible modifications to program implementation that could strengthen desired post-release outcomes.

Within- and between-person variation in morning testosterone is associated with economic risk-related decisions in athletic women across the menstrual cycle

Literature suggests that women experience ovulatory shifts in risk-taking behaviours across different domains, which might be partly attributed to changes in testosterone (T). Thus, we investigated associations between menstrual variability in T concentrations and economic risk-related decisions among athletic women. Thirty-five women were monitored across three consecutive menstrual cycles. Testing occurred on day seven (D7), 14 (D14) and 21 (D21) following the onset of menses. The morning (7 to 8 am) assessment of salivary T (sal-T) and cortisol (sal-C) was followed by the economic Hawk-Dove game (11 am to 12 pm) played in pairs, where hawk decisions were used to index risk. Morning sal-T concentration increased from D7 to D14, before decreasing on D21 (p < 0.001), representing moderate effect size (ES) changes of 0.6 to 0.8. Morning sal-C did not vary over time. Hawk choices paralleled the sal-T results, being elevated on D14 (p < 0.001) with large ES changes of 1.8. Regression analyses revealed that morning sal-T concentration was positively related (p ≤ 0.01) to the number of hawks chosen between- (beta = 0.47) and within-participants (beta = 0.10) when controlling for training hours and menstrual day. In summary, the risk-related choices of athletic women during a dyadic contest covaried with morning sal-T concentrations across the menstrual cycle. Both outcomes were positively correlated on a within- and between-person level. Confirming the major sources of T variation across the menstrual cycle, whilst discerning its relationship with other risk-related behaviours, would be worthwhile avenues for research.

The situation or the person? Individual and task‐evoked differences in BOLD activity

Investigations of between-person variability are enjoying a recent resurgence in functional magnetic resonance imaging (fMRI) research. Several recent studies have found persistent between-person differences in blood-oxygenated-level dependent (BOLD) activation patterns and resting-state functional connectivity. Conflicting findings have been reported regarding the extent to which (a) between-person or (b) within-person cognitive state differences explain differences in BOLD activation patterns. These discrepancies may arise due to statistical analysis choices, parcellation resolution, and limited sampling of task-fMRI datasets. We attempt to address these issues in a large-scale analysis of several task-fMRI paradigms. Using a novel application of multivariate distance matrix regression, we examine between-person and task-condition variability estimates across varying levels of "resolution", from a coarse region-of-interest level to the vertex-level, and across different distance metrics. These analyses revealed that under most circumstances, differences in task conditions explained a greater amount of variance in activation map differences than between-person differences. However, this finding was reversed when comparing activation maps at a "high-resolution" vertex level. More generally, we observed that when moving from "low" to "high" resolutions, the variance explained by between-person differences increased while variance explained by task conditions decreased. We further analyzed the relationships among subject-level activation maps across all task-conditions using an unsupervised clustering approach and identified a superordinate task structure. This structure went beyond conventional task labels and highlighted those experimental manipulations across task conditions that produce contrasting versus similar whole-brain activation patterns. Overall, these analyses suggest that the question of the subject- versus task-effects on BOLD activation patterns is nontrivial, and depends on the comparison "resolution," choice of distance metric, and the coding of task-conditions.

Centralized outdoor measurements of fine particulate matter as a surrogate of personal exposure for homogeneous populations

Fixed-site monitoring of particulate matter is often used as a surrogate of individual-level exposure, due to the high cost and logistic inconvenience of personal monitoring. However, studies have been limited to validate this approach in specific populations. This study aims to corroborate that centralized outdoor measurements of fine particulate matter (PM2.5) can be a surrogate of personal exposures in individuals living in a non-industrial area with high outdoor PM2.5 concentrations. The personal exposure monitors (PEMs) were first validated with a reference high-volume Andersen sampler for PM2.5 sampling. Then personal samples were collected on 113 non-smoking participants in Beijing, China, over a period of 3.5 years. Simultaneously, outdoor PM2.5 samples were collected at a central urban location. Indoor PM2.5 samples were also collected in select microenvironments where study participants frequently stayed. PM2.5 was collected onto a 37 mm quartz fiber filter in the PEM, and the mass was determined gravimetrically. Participants recorded their time-activity patterns. PEM measurements showed a high correlation with measurements from the regulatory reference method (R2 = 0.98, slope = 1.21, and a non-significant intercept). PM2.5 had mean concentrations of 196, 139, and 156 μg/m3 in outdoor, indoor and personal air, respectively. Personal exposures displayed large within-person variability (97.5% of the total variance) and negligible between-person variability (2.5%). Personal exposures were determined by outdoor concentrations (p < 0.0001), but not by indoor concentrations or the time activity pattern (p > 0.05). Linear regressions show that outdoor concentration contributed 72% of personal exposure and explained 84% of variability of personal exposure. We conclude that centralized outdoor measurement of PM2.5 is a good surrogate of personal exposure; however, the overestimation of personal exposure using outdoor concentration warrants the need for personal monitoring if the actual exposure (amount) is needed. In populations of similar lifestyle, focusing on longitudinal measurements, rather than measurements in a large number of individuals, would be a more effective exposure assessment approach, given that personal exposure variability was largely driven by temporal variability.

Neuroticism and extraversion are differentially related to between- and within-person variation of daily negative emotion and physical symptoms

Negative emotion and physical symptoms reciprocally influence each other, and are associated with neuroticism and extraversion. It remains unclear, nevertheless, how they are associated with the daily dynamic links between negative emotion and physical symptoms at between- and with-person level. This study used a daily diary design of 14 consecutive days in a Chinese college sample (n = 139, 17–22 years old, 27% males) to investigate the associations of neuroticism and extraversion with the variation and cross-day links between negative emotion and physical symptoms with dynamic structural equation modeling. Results showed substantial between- and within-person variation in daily negative emotion and physical symptoms. Neuroticism was positively associated with daily average negative emotion and physical symptoms (between-person variation); extraversion attenuated the association of physical symptoms with the next day's negative emotion (within-person variation). The findings demonstrate the value of examining within-person variation of negative emotion and physical symptoms at the daily level, and that neuroticism and extraversion have differential associations with negative emotion and physical symptoms at different levels, which have implications for interventions that target these individual characteristics to promote physical and mental well-being among college students.

Contribution of foods to absolute nutrient intake and between-person variations of nutrient intake in Korean preschoolers.

BACKGROUND/OBJECTIVESThe aim of this study was to analyze specific foods influencing absolute nutrient intake and between-person variations of nutrient intake among Korean preschoolers.SUBJECTS/METHODSThis study included 2,766 participants aged 1–5 years in the 2009–2013 Korea National Health and Nutrition Examination Surveys. Dietary data were obtained from a 24-h dietary recall method. Major food sources of absolute nutrient intake were evaluated based on percent contribution of each food. To assess the contribution of specific foods to between-person variations in nutrient intake, stepwise multiple regressions were performed and cumulative R2 was used.RESULTSWhite rice and milk were main food sources of energy, protein, carbohydrate, phosphorus, iron, potassium, thiamin, riboflavin, and niacin. The percentage of fat contributed by milk was 21.3% which was the highest, followed by pork, soybean oil, and egg. White rice accounted for 25% and 40% of total variability in total energy and carbohydrate intakes, respectively. About 39% of variation in calcium intake was explained by milk while 40% of variation in phosphorous intake was explained by cheese. The top 10 foods contributing to between-person variations in nutrient intakes were similar with food items that mainly contributed to absolute nutrient intakes. The number of foods explaining 90% of absolute amounts of nutrient intakes varied from 28 for vitamin A to 80 for iron.CONCLUSIONSThis study identified specific foods that contributed to absolute nutrient intakes and between-person variations in nutrient intakes among Korean preschoolers. Our findings can be used to develop dietary assessment tools and establish food-based dietary guidelines for young children.

Exploring Individual Differences in the Relationship Between Cultural Identity Processes and Well-Being

Although studies have explored how cultural identity impacts young people’s daily lives, these studies have exclusively focused on daily variability in cultural identity salience, overlooking daily variability in the underlying developmental processes. In the present study, we used a 12-day daily assessment conducted with 873 Hispanic college students to address these gaps by examining daily variability in ethnic and U.S. belonging, exploring between-person variability in the daily associations of ethnic and U.S. belonging with well-being, and identifying whether centrality predicts between-person variability in daily levels of these processes and their relation to well-being. Results indicated significant changes in ethnic and U.S belonging on a daily basis. Despite the positive average within-person associations between ethnic belonging and well-being, results indicated significant variability. Finally, centrality also significantly predicted between-person variability in the daily levels of these cultural processes and the within-person associations. Implications for future research are discussed.

Variations in repeated serum concentrations of UV filters, phthalates, phenols and parabens during pregnancy

BackgroundBiobank serum samples from longitudinal mother-child cohorts have been used to estimate prenatal exposures to endocrine disrupting chemicals (EDCs). However, the knowledge about variations in serum concentrations of non-persistent chemicals during pregnancy is limited. ObjectiveTo describe the within- and between-person variations in serum concentrations of non-persistent chemicals and changes over trimesters, including phthalate metabolites, parabens, phenols, and UV filters. DesignLongitudinal study with repeated blood samples from 128 healthy pregnant women during pregnancy. SettingPopulation based study at a University Hospital in Copenhagen 1999–2001. Methods503 repetitive prenatal serum samples from 128 pregnant women taken at approximately gestational week 12, 20, 30 and 40 were analyzed for 7 UV filters, 32 metabolites of 15 phthalate diesters, 8 phenols and 7 parabens by LC-MS/MS. ResultsTen of 32 phthalate metabolites from six out of 15 phthalate diesters, two of seven parabens, two of eight phenols and three of seven UV filters were measurable in more than half of the serum samples. Of these chemicals, mono‑ethyl phthalate (MEP), mono‑iso‑nonyl phthalate (MiNP), mono‑iso‑decyl phthalate (MiDP), 4‑methylbenzophenone (4‑MBP), 4‑hydroxybenzoephenone (4‑HBP) and n‑propyl paraben (nPrP) had intra-class correlation coefficients (ICC) above 0.4 in both adjusted and unadjusted analyses (0.427–0.795), indicating low within-person variation. The serum concentration of UV filters 4‑MBP and 4‑HBP significantly increased throughout pregnancy, also after adjusting for seasonal variation (4‑HBP: effect estimates 0.142–0.437, p < 0.001. 4‑MBP: effect estimates 0.156–0.458, p < 0.002.). ConclusionMEP, MiNP, MiDP, 4‑MBP, 4‑HBP and nPrP were measurable in >50% of serum samples and showed low within-person variation. Thus, it is possible with acceptable accuracy to evaluate maternal exposure during pregnancy for these non-persistent chemicals using one or more biobank serum samples. The here presented adjusted ICC values can in addition be applied as adjustment of residual variation in future studies that evaluate outcomes related to prenatal exposures.

Getting the food list 'right': an approach for the development of nutrition-relevant food lists for household consumption and expenditure surveys.

The present paper aimed to demonstrate how 24 h dietary recall data can be used to generate a nutrition-relevant food list for household consumption and expenditure surveys (HCES) using contribution analysis and stepwise regression. The analysis used data from the 2011/12 Bangladesh Integrated Household Survey (BIHS), which is nationally representative of rural Bangladesh. A total of 325 primary sampling units (PSU=village) were surveyed through a two-stage stratified sampling approach. The household food consumption module used for the analysis consisted of a 24 h open dietary recall in which the female member in charge of preparing and serving food was asked about foods and quantities consumed by the whole household. Rural Bangladesh.ParticipantsA total of 6500 households. The original 24 h open dietary recall data in the BIHS were comprised of 288 individual foods that were grouped into ninety-four similar food groups. Contribution analysis and stepwise regression were based on nutrients of public health interest in Bangladesh (energy, protein, fat, Fe, Zn, vitamin A). These steps revealed that a list of fifty-nine food items captures approximately 90 % of the total intake and up to 90 % of the between-person variation for the key nutrients based on the diets of the population. The study illustrates how 24 h open dietary recall data can be used to generate a country-specific nutrition-relevant food list that could be integrated into an HCES consumption module to enable more accurate and comprehensive household-level food and nutrient analyses.

The reproducibility of urinary ions in manganese exposed workers

PurposeManganese (Mn) is found in environmental and occupational settings, and can cause cognitive and motor impairment. Existing Mn exposure studies have not reached consensus on a valid and reproducible biomarker for Mn exposure. MethodsPreviously, global metabolomics data was generated from urine collected in October 2014 using mass spectrometry (MS). Nine ions were found to be different between persons exposed and unexposed to Mn occupationally, though their identity was not able to be determined. Here, we investigated these nine ions in a follow-up set of urine samples taken from the same cohort in January 2015, and in urine samples from a separate Mn-exposed cohort from Wisconsin. We fit an elastic net model fit using the nine ions found in the October 2014 data. ResultsThe elastic net correctly predicted exposure status in 72% of the follow-up samples collected in January 2015, and the area under the curve of the receiver operating characteristic (ROC) curve was 0.8. In the Wisconsin samples, the elastic net performed no better than chance in predicting exposure, possibly due to differences in Mn exposure levels, or unmeasured occupational or environmental co-exposures. ConclusionsThis work underscores the importance of taking repeat samples for replication studies when investigating the human urine metabolome, as both within- and between-person variances were observed. Validating and identifying promising results remains a challenge in harnessing global metabolomics for biomarker discovery in occupational cohorts.

The Precision HYpertenSIon Care (PHYSIC) study: a double-blind, randomized, repeated cross-over study

High blood pressure is the leading risk factor for premature deaths and a major cost to societies worldwide. Effective blood pressure-lowering drugs are available, but patient adherence to them is low, likely partly due to side effects. To identify patient-specific differences in treatment effects, a repeated cross-over design, where the same treatment contrasts are repeated within each patient, is needed. Such designs have been surprisingly rarely used, given the current focus on precision medicine. The Precision HYpertenSIon Care (PHYSIC) study aims to investigate if there is a consistent between-person variation in blood pressure response to the common blood pressure-lowering drug classes of a clinically relevant magnitude, given the within-person variation in blood pressure. The study will also investigate the between-person variation in side effects of the drugs. In a double-blind, randomized, repeated cross-over trial, 300 patients with mild hypertension will be treated with four blood pressure-lowering drugs (candesartan, lisinopril, amlodipine, and hydrochlorothiazide) in monotherapy, with two of the drugs repeated for each patient. If the study indicates that there is a potential for precision hypertension care, the most promising predictors of blood pressure and side effect response to the drugs will be explored, as will the potential for development of a biomarker panel to rank the suitability of blood pressure-lowering drug classes for individual patients in terms of anticipated blood pressure effects and side effects, with the ultimate goal to maximize adherence. The study follows a protocol pre-registered at ClinicalTrials.gov with the identifier NCT02774460.Trial registration: ClinicalTrials.gov identifier: NCT02774460.

"Crossover" in Depressive Symptoms Among Older Couples: Are Previous Findings Artifactual?

Objective: This study examined effects of a partner's depressive symptoms on those of a focal respondent. Method: Data were from the 2008-through-2014 waves of the Health and Retirement Study. Linear growth modeling was used to distinguish within- from between-person variation, and genetic instrumental variables to take endogeneity into account. Results: A partner's 2008 depressive symptoms had no associations with within-person change in those of a respondent between 2010 and 2014. Corresponding linkages with their between-person variation in 2010 were positive and significant for both genders. Among women, these last estimates remained intact in genetic instrumental variable models restricted to white couples. Discussion: Results indicate that contrary to previous literature, late life relationships are not marked by "crossover" of depressive symptoms. Women's affect may, however, be influenced by such transmission in the relationship's history. Beyond depression, findings suggest current theories of dyadic health effects may partly rest on flawed evidence.