Estimating intracluster correlation for ordinal data.

In this paper, we consider the estimation of intracluster correlation for ordinal data. We focus on pure-tone audiometry hearing threshold data, where thresholds are measured in 5 decibel increments. We estimate the intracluster correlation for tests from iPhone-based hearing assessment applications as a measure of test/retest reliability. We present a method to estimate the intracluster correlation using mixed effects cumulative logistic and probit models, which assume the outcome data are ordinal. This contrasts with using a mixed effects linear model which assumes that the outcome data are continuous. In simulation studies, we show that using a mixed effects linear model to estimate the intracluster correlation for ordinal data results in a negative finite sample bias, while using mixed effects cumulative logistic or probit models reduces this bias. The estimated intracluster correlation for the iPhone-based hearing assessment application is higher when using the mixed effects cumulative logistic and probit models compared to using a mixed effects linear model. When data are ordinal, using mixed effects cumulative logistic or probit models reduces the bias of intracluster correlation estimates relative to using a mixed effects linear model.

Sedentary Behaviors, Light-Intensity Physical Activity, and Healthy Aging.

Importance: Sleep duration and moderate-to-vigorous physical activity (MVPA) are associated with healthy aging, but the associations of sedentary behaviors and light-intensity physical activity (LPA) with healthy aging are still unclear. Objective: To examine the independent association of sedentary behaviors and LPA with healthy aging, and to estimate the theoretical association of replacing sedentary behavior with LPA, MVPA, or sleep with healthy aging. Design, Setting, and Participants: In this cohort study using data from the Nurses' Health Study, participants aged 50 years or older and free of major chronic diseases in 1992 were prospectively followed up for 20 years. Data were analyzed from January to May 2022. Exposures: Three measures for sedentary behaviors (hours watching television, sitting at work, and other sitting at home) and 2 measures for LPA (hours of standing or walking around at home [LPA-Home] and at work [LPA-Work]). Main Outcomes and Measures: Healthy aging was defined as survival to at least age 70 years with maintenance of 4 health domains (ie, no major chronic diseases and no impairment in subjective memory, physical function, or mental health). The isotemporal substitution model was used to evaluate the potential impact on healthy aging of replacing 1 hour of 1 behavior with equivalent duration of another. Results: Among 45 176 participants (mean [SD] age, 59.2 [6.0] years), 3873 (8.6%) women achieved healthy aging. After adjustment for covariates including MVPA, each increment of 2 hours per day in sitting watching television was associated with a 12% (95% CI, 7%-17%) reduction in the odds of healthy aging. In contrast, each increase of 2 hours per day in LPA-Work was associated with a 6% (95% CI, 3%-9%) increase in the odds of healthy aging. Replacing 1 hour of sitting watching television with LPA-Home (OR, 1.08; 95% CI, 1.05-1.12), LPA-Work (OR, 1.10; 95% CI, 1.07-1.14), or MVPA (OR, 1.28; 95% CI, 1.23-1.34) was associated with increased odds of healthy aging. Among participants who slept 7 hours per day or less, replacing television time with sleep was also associated with increased odds of healthy aging. Conclusions and Relevance: In this cohort study, longer television watching time decreased odds of healthy aging, whereas LPA and MVPA increased odds of healthy aging and replacing sitting watching television with LPA or MVPA, or with sleep in those who slept 7 hours per day or less, was associated with increased odds of healthy aging, providing evidence for rearranging 24-hour behavior to promote overall health.

Adherence to Healthy and Unhealthy Plant-Based Diets and the Risk of Gout.

Importance: Plant-based diets are increasing in popularity due, in part, to their health benefits for selected cardiometabolic diseases as well as favorable environmental impact. Little is known about how such a diet is related to gout risk. Objective: To examine associations between adherence to a plant-based diet (including healthy and unhealthy versions of this diet), as well as its 18 individual food groups, and incident gout. Design, Setting, and Participants: This prospective cohort study used data from population-based cohorts of US men and women enrolled in the Health Professionals Follow-Up Study (1986-2012) and Nurses' Health Study (1984-2010). Participants were men and women free of gout at baseline. Statistical analyses were performed over March 2020 to August 2023. Exposures: An overall plant-based diet index (PDI), as well as healthy (hPDI) and unhealthy (uPDI) versions of this index that emphasize healthy and less healthy plant-based foods, respectively. These diet indices were comprised of 18 food groups, assessed using a validated semiquantitative food frequency questionnaire. Main Outcomes and Measures: Incident cases of gout that were confirmed with a supplementary questionnaire to meet the preliminary American College of Rheumatology survey criteria for gout. Cox proportional hazards regression models were used to evaluate multivariable-adjusted associations of all 3 PDIs with incident gout using quintiles (Q) of adherence. Results: Among a total of 122 679 participants (mean [SD] age, 53.8 [9.8] years among 43 703 men; mean [SD] age, 50.9 [7.2] years among 78 976 women) over 2 704 899 person-years of follow-up, 2709 participants experienced incident gout. The overall PDI was not significantly associated with gout in either cohort (Q5 vs Q1 pooled hazard ratio [HR], 1.02 [95% CI, 0.89-1.17]; P for trend = .63). In the pooled analysis, hPDI was significantly inversely associated with risk of gout (Q5 vs Q1 HR, 0.79 [95% CI, 0.69-0.91]; P for trend = .002), while the uPDI was positively associated with risk of gout (Q5 vs Q1 HR, 1.17 [95% CI, 1.03-1.33]; P for trend = .02), particularly in women (Q5 vs Q1 HR, 1.31 [95% CI, 1.05-1.62]; P for trend = .01). In analysis of individual food groups, higher intakes of certain healthy plant foods, such as whole grains (pooled HR per 1 serving/d, 0.93 [95% CI, 0.89-0.97]) and tea and coffee (pooled HR per 1 serving/d, 0.95 [95% CI, 0.92-0.97]), as well as dairy (pooled HR per 1 serving/d, 0.86 [95% CI, 0.82-0.90]), were independently associated with a lower risk of gout, while selected unhealthy plant foods, such as fruit juice (pooled HR per 1 serving/d, 1.06 [95% CI, 1.00-1.13]) and sugar-sweetened beverages (pooled HR per 1 serving/d, 1.16 [95% CI, 1.07-1.26]) were associated with increased risk of gout. Conclusions and Relevance: The findings of this prospective cohort study of PDIs and gout support current dietary recommendations to increase consumption of healthy plant foods while lowering intake of unhealthy plant foods to mitigate gout risk.

Identifying modifiable risk factors to prevent aggressive colorectal cancer.

It remains unclear if pre-diagnostic factors influence the developmental pathways of colorectal cancer (CRC) that could enhance tumor aggressiveness. This study used prospective data from 205,489 cancer-free US health professionals to investigate the associations of 31 known or putative risk factors with the risk of aggressive CRC. Tumor aggressiveness was characterized by three endpoints: aggressive CRC (cancer that causes death within 5 years of diagnosis), fatal CRC, and tumor stage at diagnosis. The data augmentation method was used to assess the difference in the associations between risk factors and endpoints. We documented 3201 CRC cases, of which 899 were aggressive. The protective associations of undergoing lower endoscopy (hazard ratios [HR] 0.43, 95% confidence interval (CI) 0.37, 0.49 for aggressive versus HR 0.61, 95% CI 0.56, 0.67 for non-aggressive) and regular use of aspirin (HR 0.70, 95% CI 0.61, 0.81 versus HR 0.84, 95% CI 0.77, 0.92) were stronger for aggressive than non-aggressive CRC (pHeterogeneity <0.05). Lower intake of whole grains or cereal fiber and greater dietary inflammatory potential were associated with a higher risk of aggressive but not non-aggressive CRC. The remaining risk factors showed comparable associations with aggressive CRC and non-aggressive CRC. Aggressive cases were more likely to have KRAS-mutated tumors but less likely to have distal or MSI-high tumors (p < .007). Similar results were observed for fatal CRC and advanced tumor stages at diagnosis. These findings provide initial evidence for the role of pre-diagnostic risk factors in the pathogenesis of aggressive CRC and suggest research priorities for preventive interventions.

Prediction of 24-Hour Urinary Sodium Excretion Using Machine-Learning Algorithms.

BACKGROUND: Accurate quantification of sodium intake based on self-reported dietary assessments has been a persistent challenge. We aimed to apply machine-learning (ML) algorithms to predict 24-hour urinary sodium excretion from self-reported questionnaire information. METHODS AND RESULTS: We analyzed 3454 participants from the NHS (Nurses' Health Study), NHS-II (Nurses' Health Study II), and HPFS (Health Professionals Follow-Up Study), with repeated measures of 24-hour urinary sodium excretion over 1 year. We used an ensemble approach to predict averaged 24-hour urinary sodium excretion using 36 characteristics. The TOHP-I (Trial of Hypertension Prevention I) was used for the external validation. The final ML algorithms were applied to 167 920 nonhypertensive adults with 30-year follow-up to estimate confounder-adjusted hazard ratio (HR) of incident hypertension for predicted sodium. Averaged 24-hour urinary sodium excretion was better predicted and calibrated with ML compared with the food frequency questionnaire (Spearman correlation coefficient, 0.51 [95% CI, 0.49-0.54] with ML; 0.19 [95% CI, 0.16-0.23] with the food frequency questionnaire; 0.46 [95% CI, 0.42-0.50] in the TOHP-I). However, the prediction heavily depended on body size, and the prediction of energy-adjusted 24-hour sodium excretion was modestly better using ML. ML-predicted sodium was modestly more strongly associated than food frequency questionnaire-based sodium in the NHS-II (HR comparing Q5 versus Q1, 1.48 [95% CI, 1.40-1.56] with ML; 1.04 [95% CI, 0.99-1.08] with the food frequency questionnaire), but no material differences were observed in the NHS or HPFS. CONCLUSIONS: The present ML algorithm improved prediction of participants' absolute 24-hour urinary sodium excretion. The present algorithms may be a generalizable approach for predicting absolute sodium intake but do not substantially reduce the bias stemming from measurement error in disease associations.

Calibration of citrus intake assessed by food frequency questionnaires using urinary proline betaine in an observational study setting.

BACKGROUND: Whether observational study can be employed to establish calibration equations for self-reported dietary intake using food biomarkers is unknown. OBJECTIVES: This study aims to demonstrate the feasibility of obtaining calibration equations based on food biomarkers and 7-d diet records (7DDRs) to correct measurement errors of food frequency questionnaires (FFQs) in an observational study setting. METHODS: The study population consisted of 669 males and 749 females from the Women's and Men's Lifestyle Validation Studies. In the training set, the biomarker-predicted intake derived by regressing 7DDR-assessed intake on urinary proline betaine concentration was regressed on the FFQ-assessed intake to obtain the calibration equations. The regression coefficients were applied to the test set to calculate the calibrated FFQ intake. We examined total citrus as well as individual citrus fruits/beverages. RESULTS: Urinary proline betaine was moderately correlated with orange juice intake (Pearson correlation [r] = 0.53 for 7DDR and 0.48 for FFQ) but only weakly correlated with intakes of orange (r = 0.12 for 7DDR and 0.15 for FFQ) and grapefruit (r = 0.14 for 7DDR and 0.09 for FFQ). The FFQ-assessed citrus intake was systematically higher than the 7DDR-assessed intake, and after calibrations, the mean calibrated FFQ measurements were almost identical to 7DDR assessments. In the test set, the mean intake levels from 7DDRs, FFQs, and calibrated FFQs were 62.5, 75.3, and 63.2 g/d for total citrus; 41.6, 42.5, and 41.9 g/d for orange juice; 11.8, 24.3, and 12.3 g/d for oranges; and 8.3, 9.3, and 8.6 g/d for grapefruit, respectively. We observed larger differences between calibrated FFQ and 7DDR assessments at the extreme ends of intake, although, on average, good agreements were observed for all citrus except grapefruit. CONCLUSIONS: Our 2-step calibration approach has the potential to be adapted to correct systematic measurement error for other foods/nutrients with established food biomarkers in a cost effective way.

The Cancer Spectrum Theory.

SUMMARY: Biological characteristics of tumors are heterogeneous, forming spectra in terms of several factors such as age at onset, anatomic spatial localization, tumor subtyping, and the degree of tumor aggressiveness (encompassing a neoplastic property spectrum). Instead of blindly using dichotomized approaches, the application of the multicategorical and continuous analysis approaches to detailed cancer spectrum data can contribute to a better understanding of the etiology of cancer, ultimately leading to effective prevention and precision oncology. We provide examples of cancer spectra and emphasize the importance of integrating the cancer spectrum theory into large-scale population cancer research.

Alcohol and colorectal cancer risk subclassified by mutational signatures of DNA mismatch repair deficiency.

BACKGROUND: We examined whether the association between alcohol consumption and CRC incidence was stronger for tumors with higher contributions of defective MMR (dMMR)-related tumor mutational signatures (TMSs). METHODS: We used data from 227,916 men and women who participated in the Nurses' Health Study (1980-2016), the Nurses' Health Study II (1991-2017), and the Health Professionals Follow-up Study (1986-2016). Dietary data was collected every 4 years through validated food frequency questionnaires. Relative contributions of two dMMR-related TMSs (c-dMMRa/SBS15 and c-dMMRb/SBS26) were quantified using whole-exome sequencing data in a subset of incident CRC cases. Duplication-method Cox proportional hazards regression models were used to assess the association between alcohol consumption and the risk of CRC subtypes according to different contributions of the TMSs. All statistical tests were 2-sided. RESULTS: We documented 825 incident CRC cases with available TMS data over 26-36 years of follow-up. The association between alcohol consumption and CRC incidence was stronger for tumors with higher contributions of c-dMMRb/SBS26 (P-heterogeneitytrend = 0.02) compared to tumors with lower contributions of this TMS. Compared with nondrinkers, drinkers with ≥15 g/d of alcohol had a high risk of c-dMMRb/SBS26-high CRC [multivariable-adjusted HR: 2.43 (95% CI: 1.55-3.82)], but not c-dMMRb/SBS26-low CRC [0.86 (95% CI: 0.57-1.28)] or c-dMMRb/SBS26-moderate CRC [1.14 (95% CI: 0.76-1.71)]. No significant differential associations were observed for c-dMMRa/SBS15 (P-heterogeneitytrend = 0.41). CONCLUSIONS: High alcohol consumption was associated with an increased incidence of CRC containing higher contributions of c-dMMRb/SBS26, suggesting that alcohol consumption may be involved in colorectal carcinogenesis through the DNA mismatch repair pathway.

Targeting strategies of antenatal balanced energy and protein supplementation in Addis Ababa, Ethiopia: study protocol for a randomized effectiveness study.

BACKGROUND: Antenatal balanced energy and protein (BEP) supplements have well-documented benefits for pregnancy outcomes. However, considerable practical gaps remain in the effective and cost-effective delivery of antenatal BEP supplements at scale in low- and middle-income countries. METHODS: A randomized effectiveness study will be conducted in two sub-cities of Addis Ababa, Ethiopia, to evaluate the effectiveness, cost-effectiveness, and implementation of different targeting strategies of antenatal BEP supplements. Pregnant women aged 18 to 49, with a gestational age of 24 weeks or less, and attending antenatal visits in one of the nine study health facilities are eligible for enrollment. In six of the health facilities, participants will be randomized to one of three study arms: control (Arm 1), targeted BEP provision based on baseline nutritional status (Arm 2), and targeted BEP supplementation based on baseline nutritional status and monthly gestational weight gain (GWG) monitoring (Arm 3). In the remaining three facilities, participants will be assigned to universal BEP provision (Arm 4). Participants in Arms 2 and 3 will receive BEP supplements if they have undernutrition at enrollment, as defined by a baseline body mass index less than 18.5 kg/m2 or mid-upper arm circumference less than 23 cm. In Arm 3, in addition to targeting based on baseline undernutrition, regular weight measurements will be used to identify insufficient GWG and inform the initiation of additional BEP supplements. Participants in Arm 4 will receive BEP supplements until the end of pregnancy, regardless of baseline nutritional status or GWG. All participants will receive standard antenatal care, including iron and folic acid supplementation. A total of 5400 pregnant women will be enrolled, with 1350 participants in each arm. Participants will be followed up monthly during their visits to the antenatal facilities until delivery. Maternal and infant health status will be evaluated within 72 h after delivery and at 6 weeks postpartum. The effectiveness and cost-effectiveness of the different BEP targeting strategies in preventing adverse pregnancy outcomes will be compared across arms. Qualitative data will be analyzed to assess the feasibility, acceptability, and implementation of different supplementation strategies. DISCUSSION: This study will inform global recommendations and operational guidelines for the effective and cost-effective delivery of antenatal BEP supplements. The targeted approaches have the potential for broader scale-up in Ethiopia and other low-resource settings with a high burden of undernutrition among pregnant women. TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT06125860. Registered November 9, 2023.

Dietary Fiber Intake and Risk of Advanced and Aggressive Forms of Prostate Cancer: A Pooled Analysis of 15 Prospective Cohort Studies.

BACKGROUND: Evidence of an association between dietary fiber intake and risk of advanced and aggressive forms of prostate cancer (PC) and PC mortality is limited. OBJECTIVE: The aim of this study was to examine associations between intakes of dietary fiber overall and by food source and risk of advanced and aggressive forms of PC. DESIGN: The study design was a pooled analysis of the primary data from 15 cohorts in 3 continents. Baseline dietary fiber intake was assessed using a validated food frequency questionnaire or diet history in each study. PARTICIPANTS/SETTING: There were 842 149 men followed for up to 9 to 22 years between 1985 and 2009 across studies. MAIN OUTCOME MEASURES: The primary outcome measures were advanced (stage T4, N1, or M1 or PC mortality), advanced restricted (excluded men with missing stage and those with localized PC who died of PC), and high-grade PC (Gleason score ≥8 or poorly differentiated/undifferentiated) and PC mortality. STATISTICAL ANALYSIS PERFORMED: Study-specific multivariable hazard ratios (MVHR) were calculated using Cox proportional hazards regression and pooled using random effects models. RESULTS: Intake of dietary fiber overall, from fruits, and from vegetables was not associated with risk of advanced (n = 4863), advanced restricted (n = 2978), or high-grade PC (n = 9673) or PC mortality (n = 3097). Dietary fiber intake from grains was inversely associated with advanced PC (comparing the highest vs lowest quintile, MVHR 0.84; 95% CI 0.76-0.93), advanced restricted PC (MVHR 0.85; 95% CI 0.74-0.97), and PC mortality (MVHR 0.78; 95% CI 0.68-0.89); statistically significant trends were noted for each of these associations (P ≤ .03), and a null association was observed for high-grade PC for the same comparison (MVHR 1.00; 95% CI 0.93-1.07). The comparable results were 1.06 (95% CI 1.01-1.10; P value, test for trend = .002) for localized PC (n = 35,199) and 1.05 (95% CI 0.99-1.11; P value, test for trend = .04) for low/intermediate grade PC (n = 34 366). CONCLUSIONS: Weak nonsignificant associations were observed between total dietary fiber intake and risk of advanced forms of PC, high-grade PC, and PC mortality. High dietary fiber intake from grains was associated with a modestly lower risk of advanced forms of PC and PC mortality.

Causal Selection of Covariates in Regression Calibration for Mismeasured Continuous Exposure.

Regression calibration as developed by Rosner, Spiegelman, and Willett is used to adjust the bias in effect estimates due to measurement error in continuous exposures. The method involves two models: a measurement error model relating the mismeasured exposure to the true (or gold-standard) exposure and an outcome model relating the mismeasured exposure to the outcome. However, no comprehensive guidance exists for determining which covariates should be included in each model. In this article, we investigate the selection of the minimal and most efficient covariate adjustment sets under a causal inference framework. We show that to address the measurement error, researchers must adjust for, in both measurement error and outcome models, any common causes (1) of true exposure and the outcome and (2) of measurement error and the outcome. We also show that adjusting for so-called prognostic variables that are independent of true exposure and measurement error in the outcome model, may increase efficiency, while adjusting for any covariates that are associated only with true exposure generally results in efficiency loss in realistic settings. We apply the proposed covariate selection approach to the Health Professional Follow-up Study dataset to study the effect of fiber intake on cardiovascular disease. Finally, we extend the originally proposed estimators to a nonparametric setting where effect modification by covariates is allowed.

Weighting estimation in the cause-specific Cox regression with partially missing causes of failure.

Complex diseases are often analyzed using disease subtypes classified by multiple biomarkers to study pathogenic heterogeneity. In such molecular pathological epidemiology research, we consider a weighted Cox proportional hazard model to evaluate the effect of exposures on various disease subtypes under competing-risk settings in the presence of partially or completely missing biomarkers. The asymptotic properties of the inverse and augmented inverse probability-weighted estimating equation methods are studied with a general pattern of missing data. Simulation studies have been conducted to demonstrate the double robustness of the estimators. For illustration, we applied this method to examine the association between pack-years of smoking before the age of 30 and the incidence of colorectal cancer subtypes defined by a combination of four tumor molecular biomarkers (statuses of microsatellite instability, CpG island methylator phenotype, BRAF mutation, and KRAS mutation) in the Nurses' Health Study cohort.

Hypothesis Tests for Continuous Audiometric Threshold Data.

OBJECTIVES: Hypothesis tests for hearing threshold data may be challenging due to the special structure of the response variable, which consists of the measurements from the participant's two ears at multiple frequencies. The commonly-used methods may have inflated type I error rates for the global test that examines whether exposure-hearing threshold associations exist in at least one of the frequencies. We propose using both-ear methods, including all frequencies in the same model for hypothesis testing. DESIGN: We compared the both-ear method to commonly used single-ear methods, such as the worse-ear, better-ear, left/right-ear, average-ear methods, and both-ear methods that evaluate individual audiometric frequencies in separate models, through both theoretical consideration and a simulation study. Differences between the methods were illustrated using hypothesis tests for the associations between the Dietary Approaches to Stop Hypertension adherence score and 3-year change in hearing thresholds among participants in the Conservation of Hearing Study. RESULTS: We found that (1) in the absence of ear-level confounders, the better-ear, worse-ear and left/right-ear methods have less power for frequency-specific tests and for the global test; (2) in the presence of ear-level confounders, the better-ear and worse-ear methods are invalid, and the left/right-ear and average-ear methods have less power, with the power loss in the left/right-ear much greater than the average-ear method, for frequency-specific tests and for the global test; and (3) the both-ear method with separate analyses for individual frequencies is invalid for the global test. CONCLUSIONS: For hypothesis testing to evaluate whether there are significant associations between an exposure of interest and audiometric hearing threshold measurements, the both-ear method that includes all frequencies in the same model is the recommended analytic approach.

Soft classification and regression analysis of audiometric phenotypes of age-related hearing loss.

Age-related hearing loss has a complex etiology. Researchers have made efforts to classify relevant audiometric phenotypes, aiming to enhance medical interventions and improve hearing health. We leveraged existing pattern analyses of age-related hearing loss and implemented the phenotype classification via quadratic discriminant analysis (QDA). We herein propose a method for analyzing the exposure effects on the soft classification probabilities of the phenotypes via estimating equations. Under reasonable assumptions, the estimating equations are unbiased and lead to consistent estimators. The resulting estimator had good finite sample performances in simulation studies. As an illustrative example, we applied our proposed methods to assess the association between a dietary intake pattern, assessed as adherence scores for the dietary approaches to stop hypertension diet calculated using validated food-frequency questionnaires, and audiometric phenotypes (older-normal, metabolic, sensory, and metabolic plus sensory), determined based on data obtained in the Nurses' Health Study II Conservation of Hearing Study, the Audiology Assessment Arm. Our findings suggested that participants with a more healthful dietary pattern were less likely to develop the metabolic plus sensory phenotype of age-related hearing loss.

The Impact of Excluding Adverse Neonatal Outcomes on the Creation of Gestational Weight Gain Charts Among Women from Low- and Middle-income Countries with Normal and Overweight BMI.

BACKGROUND: Existing gestational weight gain (GWG) charts vary considerably in their choice of exclusion/inclusion criteria, and it is unclear to what extent these criteria create differences in the charts' percentile values. OBJECTIVES: We aimed to establish the impact of including/excluding pregnancies with adverse neonatal outcomes when constructing GWG charts. METHODS: This is an individual participant data analysis from 31 studies from low- and middle-income countries. We created a dataset that included all participants and a dataset restricted to those with no adverse neonatal outcomes: preterm < 37 wk, small or large for gestational age, low birth weight < 2500 g, or macrosomia > 4000 g. Quantile regression models were used to create GWG curves from 9 to 40 wk, stratified by prepregnancy BMI, in each dataset. RESULTS: The dataset without the exclusion criteria applied included 14,685 individuals with normal weight and 4831 with overweight. After removing adverse neonatal outcomes, 10,479 individuals with normal weight and 3466 individuals with overweight remained. GWG distributions at 13, 27, and 40 wk were virtually identical between the datasets with and without the exclusion criteria, except at 40 wk for normal weight and 27 wk for overweight. For the 10th and 90th percentiles, the differences between the estimated GWG were larger for overweight (∼1.5 kg) compared with normal weight (<1 kg). Removal of adverse neonatal outcomes had minimal impact on GWG trajectories of normal weight. For overweight, the percentiles estimated in the dataset without the criteria were slightly higher than those in the dataset with the criteria applied. Nevertheless, differences were <1 kg and virtually nonexistent at the end of pregnancy. CONCLUSIONS: Removing pregnancies with adverse neonatal outcomes has little or no influence on the GWG trajectories of individuals with normal and overweight.

CUL4B mutations impair human cortical neurogenesis through PP2A-dependent inhibition of AKT and ERK.

Mutation in CUL4B gene is one of the most common causes for X-linked intellectual disability (XLID). CUL4B is the scaffold protein in CUL4B-RING ubiquitin ligase (CRL4B) complex. While the roles of CUL4B in cancer progression and some developmental processes like adipogenesis, osteogenesis, and spermatogenesis have been studied, the mechanisms underlying the neurological disorders in patients with CUL4B mutations are poorly understood. Here, using 2D neuronal culture and cerebral organoids generated from the patient-derived induced pluripotent stem cells and their isogenic controls, we demonstrate that CUL4B is required to prevent premature cell cycle exit and precocious neuronal differentiation of neural progenitor cells. Moreover, loss-of-function mutations of CUL4B lead to increased synapse formation and enhanced neuronal excitability. Mechanistically, CRL4B complex represses transcription of PPP2R2B and PPP2R2C genes, which encode two isoforms of the regulatory subunit of protein phosphatase 2 A (PP2A) complex, through catalyzing monoubiquitination of H2AK119 in their promoter regions. CUL4B mutations result in upregulated PP2A activity, which causes inhibition of AKT and ERK, leading to premature cell cycle exit. Activation of AKT and ERK or inhibition of PP2A activity in CUL4B mutant organoids rescues the neurogenesis defect. Our work unveils an essential role of CUL4B in human cortical development.

Dietary protein intake in midlife in relation to healthy aging - results from the prospective Nurses' Health Study cohort.

BACKGROUND: Protein intake plays an important role in maintaining the health status of older adults. However, few epidemiologic studies examined midlife protein intake in relation to healthy aging. OBJECTIVES: The objective of this study was to evaluate the long-term role of dietary protein intake in healthy aging among female participants in the prospective Nurses' Health Study (NHS) cohort. METHODS: We included 48,762 NHS participants aged <60 y in 1984. Total protein, animal protein, dairy protein (a subset of animal protein), and plant protein were derived from validated food frequency questionnaires. Healthy aging was defined as being free from 11 major chronic diseases, having good mental health, and not having impairments in either cognitive or physical function, as assessed in the 2014 or 2016 NHS participant questionnaires. We used multivariate logistic regression adjusted for lifestyle, demographics, and health status to estimate the odds ratios (ORs) and 95% confidence intervals for protein intake in relation to healthy aging. RESULTS: A total of 3721 (7.6%) NHS participants met our healthy aging definition. Protein intake was significantly associated with higher odds of healthy aging. The ORs (95% confidence intervals) per 3%-energy increment with healthy aging were 1.05 (1.01, 1.10) for total protein, 1.07 (1.02, 1.11) for animal protein, 1.14 (1.06, 1.23) for dairy protein, and 1.38 (1.24, 1.54) for plant protein. Plant protein was also associated with higher odds of absence of physical function limitations and good mental status. In substitution analyses, we observed significant positive associations for the isocaloric replacement of animal or dairy protein, carbohydrate, or fat with plant protein (ORs for healthy aging: 1.22-1.58 for 3% energy replacement with plant protein). CONCLUSIONS: Dietary protein intake, especially plant protein, in midlife, is associated with higher odds of healthy aging and with several domains of positive health status in a large cohort of female nurses.

Two Randomized Trials of Low-Dose Calcium Supplementation in Pregnancy.

BACKGROUND: The World Health Organization recommends 1500 to 2000 mg of calcium daily as supplementation, divided into three doses, for pregnant persons in populations with low dietary calcium intake in order to reduce the risk of preeclampsia. The complexity of the dosing scheme, however, has led to implementation barriers. METHODS: We conducted two independent randomized trials of calcium supplementation, in India and Tanzania, to assess the noninferiority of a 500-mg daily dose to a 1500-mg daily dose of calcium supplementation. In each trial, the two primary outcomes were preeclampsia and preterm birth, and the noninferiority margins for the relative risks were 1.54 and 1.16, respectively. RESULTS: A total of 11,000 nulliparous pregnant women were included in each trial. The cumulative incidence of preeclampsia was 3.0% in the 500-mg group and 3.6% in the 1500-mg group in the India trial (relative risk, 0.84; 95% confidence interval [CI], 0.68 to 1.03) and 3.0% and 2.7%, respectively, in the Tanzania trial (relative risk, 1.10; 95% CI, 0.88 to 1.36) - findings consistent with the noninferiority of the lower dose in both trials. The percentage of live births that were preterm was 11.4% in the 500-mg group and 12.8% in the 1500-mg group in the India trial (relative risk, 0.89; 95% CI, 0.80 to 0.98), which was within the noninferiority margin of 1.16; in the Tanzania trial, the respective percentages were 10.4% and 9.7% (relative risk, 1.07; 95% CI, 0.95 to 1.21), which exceeded the noninferiority margin. CONCLUSIONS: In these two trials, low-dose calcium supplementation was noninferior to high-dose calcium supplementation with respect to the risk of preeclampsia. It was noninferior with respect to the risk of preterm live birth in the trial in India but not in the trial in Tanzania. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT03350516; Clinical Trials Registry-India number, CTRI/2018/02/012119; and Tanzania Medicines and Medical Devices Authority Trials Registry number, TFDA0018/CTR/0010/5).

Comparison between inverse-probability weighting and multiple imputation in Cox model with missing failure subtype.

Identifying and distinguishing risk factors for heterogeneous disease subtypes has been of great interest. However, missingness in disease subtypes is a common problem in those data analyses. Several methods have been proposed to deal with the missing data, including complete-case analysis, inverse-probability weighting, and multiple imputation. Although extant literature has compared these methods in missing problems, none has focused on the competing risk setting. In this paper, we discuss the assumptions required when complete-case analysis, inverse-probability weighting, and multiple imputation are used to deal with the missing failure subtype problem, focusing on how to implement these methods under various realistic scenarios in competing risk settings. Besides, we compare these three methods regarding their biases, efficiency, and robustness to model misspecifications using simulation studies. Our results show that complete-case analysis can be seriously biased when the missing completely at random assumption does not hold. Inverse-probability weighting and multiple imputation estimators are valid when we correctly specify the corresponding models for missingness and for imputation, and multiple imputation typically shows higher efficiency than inverse-probability weighting. However, in real-world studies, building imputation models for the missing subtypes can be more challenging than building missingness models. In that case, inverse-probability weighting could be preferred for its easy usage. We also propose two automated model selection procedures and demonstrate their usage in a study of the association between smoking and colorectal cancer subtypes in the Nurses' Health Study and Health Professional Follow-Up Study.