Measurement and Validation of the Comprehensive Score for Financial Toxicity (COST) in a Population With Diabetes

OBJECTIVE

The Comprehensive Score for Financial Toxicity-Functional Assessment of Chronic Illness Therapy (COST-FACIT) is a validated instrument measuring financial distress among people with cancer. The reliability and construct validity of the 11-item COST-FACIT were examined in adults with diabetes and high A1C.

RESEARCH DESIGN AND METHODS

We examined the factor structure (exploratory factor analysis), internal consistency reliability (Cronbach α), floor/ceiling effects, known-groups validity, and predictive validity among a sample of 600 adults with diabetes and high A1C.

RESULTS

COST-FACIT demonstrated a two-factor structure with high internal consistency: general financial situation (7-items, α = 0.86) and impact of illness on financial situation (4-items, α = 0.73). The measure demonstrated a ceiling effect for 2% of participants and floor effects for 7%. Worse financial toxicity scores were observed among adults who were women, were below the poverty line, had government-sponsored health insurance, were middle-aged, were not in the workforce, and had less educational attainment (P < 0.01). Worse financial toxicity was observed for those engaging in cost coping behaviors, such as taking less or skipping medicines, delaying care, borrowing money, "maxing out" the limit on credit cards, and not paying bills (P < 0.01). In regression models for the full measure and its two factors, worse financial toxicity was correlated with higher A1C (P < 0.01), higher levels of diabetes distress (P < 0.01), more chronic conditions (P < 0.01), and more depressive symptoms (P < 0.01).

CONCLUSIONS

Findings support both the reliability and validity of the COST-FACIT tool among adults with diabetes and high A1C levels. More research is needed to support the use of the COST-FACIT tool as a clinically relevant patient-centered instrument for diabetes care.

A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children

As a guide to establishing a safe exposure level for fluoride exposure in pregnancy, we applied benchmark dose modeling to data from two prospective birth cohort studies. We included mother-child pairs from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort in Mexico and the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort in Canada. Maternal urinary fluoride concentrations (U-F, in mg/L, creatinine-adjusted) were measured in urine samples obtained during pregnancy. Children were assessed for intelligence quotient (IQ) at age 4 (n = 211) and between six and 12 years (n = 287) in the ELEMENT cohort, and three to four years (n = 407) in the MIREC cohort. We calculated covariate-adjusted regression coefficients and their standard errors to assess the association of maternal U-F concentrations with children's IQ measures. Assuming a benchmark response of 1 IQ point, we derived benchmark concentrations (BMCs) and benchmark concentration levels (BMCLs). No deviation from linearity was detected in the dose-response relationships, but boys showed lower BMC values than girls. Using a linear slope for the joint cohort data, the BMC for maternal U-F associated with a 1-point decrease in IQ scores was 0.31 mg/L (BMCL, 0.19 mg/L) for the youngest boys and girls in the two cohorts, and 0.33 mg/L (BMCL, 0.20 mg/L) for the MIREC cohort and the older ELEMENT children. Thus, the joint data show a BMCL in terms of the adjusted U-F concentrations in the pregnant women of approximately 0.2 mg/L. These results can be used to guide decisions on preventing excess fluoride exposure in pregnant women.

Epitope Analysis and Efficacy Evaluation of Phosphatase 2C (PP2C) DNA Vaccine Against Toxoplasma gondii Infection

Toxoplasma gondii infects almost all warm-blooded animals and negatively affects the health of a wide range of these animals, including humans. Protein phosphatase 2C (PP2C) is a T. gondii protein secreted by rhoptry organelles during host cell invasion. However, very little is known about whether this protein can induce protective immunity against T. gondii. In this study, bioinformatics analysis of PP2C revealed some useful information in the context of anti-toxoplasmosis treatments and vaccine research. In addition, the PP2C gene was amplified, and a eukaryotic expression vector (pEGFP-PP2C) was successfully constructed to express PP2C. Finally, the constructed pEGFP-PP2C was injected into mice to evaluate whether it could induce immunoprotection. Compared with the control groups, we found that immunizations with the pEGFP-PP2C plasmid could elicit specific IgG antibodies and cytokines against T. gondii infection. The survival of mice immunized with the pEGFP-PP2C plasmid was significantly prolonged compared with that of the control group mice. Based on the ability of pEGFP-PP2C to induce specific immune responses against T. gondii, we propose that PP2C merits consideration as a potential vaccine candidate against toxoplasmosis.

Cumulative Childhood Lead Levels in Relation to Sleep During Adolescence

STUDY OBJECTIVES

Lead exposure has been linked to adverse cognitive outcomes among children, and sleep disturbances could potentially mediate these relationships. As a first step, whether childhood lead levels are linked to sleep disturbances must be ascertained. Prior studies of lead and sleep are scarce and rely on parent-reported sleep data.

METHODS

The study population included 395 participants from the Early Life Exposure in Mexico to Environmental Toxicants project, a group of sequentially enrolled birth cohorts from Mexico City. Blood lead levels measured from ages 1 to 4 years were used to calculate a cumulative measure of early childhood lead levels. Average sleep duration, sleep fragmentation, and movement index were assessed once between the ages of 9 and 18 years with wrist actigraphs worn for a continuous 7-day interval. Linear regression models were fit with average sleep duration, fragmentation, or movement as the outcome and cumulative lead levels divided into quartiles as the exposure, adjusted for age, sex, and maternal education.

RESULTS

Mean (standard deviation) age at follow-up was 13.8 (1.9) years, and 48% of participants were boys. Median (interquartile range) cumulative childhood lead level was 13.7 (10.8, 18.0) μg/dL. Patients in the highest quartile of the cumulative childhood lead group had on average 23 minutes less sleep than those in the first quartile in adolescence (95% confidence interval [7, 39]; P, trend = .02). Higher cumulative lead level was associated with higher sleep fragmentation in younger adolescents (younger than 14 years) only (P, interaction = .02).

CONCLUSIONS

Shorter sleep duration may represent an as-yet unrecognized adverse consequence of lead exposure in youth.

Metabolomic Determinants of Metabolic Risk in Mexican Adolescents

OBJECTIVE

The goal of this study was to identify metabolites associated with metabolic risk, separately by sex, in Mexican adolescents.

METHODS

Untargeted metabolomic profiling was carried out on fasting serum of 238 youth aged 8 to 14 years, and metabolites associated with a metabolic syndrome risk z-score (MetRisk z-score) were identified separately for boys and girls, using the simulation and extrapolation algorithm. Associations of each metabolite with MetRisk z-score were examined using linear regression models that accounted for maternal education, child's age, and pubertal status.

RESULTS

Of the 938 features identified in metabolomics analysis, 7 named compounds (of 27 identified metabolites) were associated with MetRisk z-score in girls, and 3 named compounds (of 14 identified) were associated with MetRisk z-score in boys. In girls, diacylglycerol (DG) 16:0/16:0, 1,3-dielaidin, myo-inositol, and urate corresponded with higher MetRisk z-score, whereas N-acetylglycine, thymine, and dodecenedioic acid were associated with lower MetRisk z-score. For example, each z-score increment in DG 16:0/16:0 corresponded with 0.60 (95% CI: 0.47-0.74) units higher MetRisk z-score. In boys, positive associations of DG 16:0/16:0, tyrosine, and 5'-methylthioadenosine with MetRisk z-score were found.

CONCLUSIONS

Metabolites on lipid, amino acid, and carbohydrate metabolism pathways are associated with metabolic risk in girls. Compounds on lipid and DNA pathways correspond with metabolic risk in boys.

Structural and antigenic analysis and cloning of surface antigen protein 5 in Toxoplasma gondii

Toxoplasma gondii is identified as an obligate intracellular apicomplexan parasite that infects warm blooded animals and humans worldwide. SAG5 protein includes SAG5A, -5B, -5C, -5D, and -5E five subtypes. SAG5A, -5B, -5C, and -5D are expressed on the surface of Toxoplasma gondii. In this study, we used online T-Coffee tool to analyze SAG5 proteins sequence alignment. SMART software was used to predict secondary structures of SAG5A, -5B, -5C, and -5D. The 3D models of SAG5 proteins were constructed and analyzed with SWISS-MODEL server and VMD software. Results indicated that SAG5A, -5B, -5C, and -5D are highly homologous proteins. Furthermore, liner-B cell epitopes and Th-cell epitopes of the four proteins were predicted using DNAMAN software and Epitope Database online service. The bioinformatics analysis of SAG5A, -5B, -5C, and -5D proteins could provide valuable information on prevention and treatment of toxoplasmosis. In addition, the four genes were obtained by PCR and inserted into an eukaryotic expression vector pEGFP-C1 respectively. Identified by restriction enzyme digestion, the four recombinant plasmids were transfected into HEK 293-T cells and tested by RT-PCR. Results showed that the constructed plasmids were all transfected to HEK 293-T cells successfully.

Effects of Graded Levels of Isomaltooligosaccharides on the Performance, Immune Function and Intestinal Status of Weaned Pigs

The objective of this study was to investigate the effects of graded levels of isomaltooligosaccharides (IMO) on the performance, immune function and intestinal microflora and intestinal mucosal morphology of weaned pigs. In a 28-day experiment, one hundred eighty, twenty eight-day-old, crossbred (Duroc×Large White×Landrace), weaned pigs, with an initial body weight of 8.19±1.45 kg, were fed either an unsupplemented corn-soybean meal based diet or similar diets supplemented with 0.2%, 0.4%, 0.6%, or 0.8% IMO added at the expense of corn. Each treatment was replicated six times with six pigs (three barrows and three gilts) per pen. From day 0 to 14, weight gain was linearly increased (p<0.05), while gain:feed (p<0.05) was linearly improved and diarrhea rate (p = 0.05) linearly declined as the IMO level increased. On d 14, the level of the immunoglobulins IgA, IgM, and IgG in the serum of pigs were linearly increased (p<0.05) with increasing IMO supplementation. Interleukin-6 (IL-6) was linearly (p<0.05) and quadratically (p<0.05) decreased as IMO intake increased. From day 15 to 28, there was a trend for weight gain to be linearly increased, and IL-2 was linearly (p<0.05) increased as IMO supplementation increased on d 28. Over the entire experiment, weight gain was linearly increased (p<0.05), while gain:feed (p<0.05) was linearly improved and diarrhea rate (p<0.05) was linearly decreased as the IMO level increased. Supplementation with IMO had no effect on the intestinal microflora of pigs in the ileum and cecum of pigs, as well as the villus height and crypt depth in the ileum and jejunum (p>0.05). These results indicate that dietary inclusion of IMO increases weight gain, gain:feed and enhanced the immune status of pigs, and could be a valuable feed additive for use in weaned pigs, particularly during the period immediately after weaning.

Statistical analysis of repeated measurements with informative censoring times

Incomplete repeated measurement data often arise in medical studies. A problem that has recently drawn much attention in the literature in this situation is that the incompleteness or missingness is informative or related to the underlying variable of interest. In this paper we propose a non-parametric global test for treatment comparison in the presence of informative incompleteness. A semi-parametric regression model is also presented for assessing conditional treatment effects given the drop-out patterns, adopting the idea similar to that behind the pattern-mixture modelling approach and discussed in Shih and Quan. The proposed methods can be easily implemented and are conceptually simple and similar too, but can be applied to more general cases than those given in Yao et al. They are evaluated by numerical studies and applied to data from a clinical trial of adult schizophrenics.

Marginal models for longitudinal continuous proportional data

Continuous proportional data arise when the response of interest is a percentage between zero and one, e.g., the percentage of decrease in renal function at different follow-up times from the baseline. In this paper, we propose methods to directly model the marginal means of the longitudinal proportional responses using the simplex distribution of Barndorff-Nielsen and Jørgensen that takes into account the fact that such responses are percentages restricted between zero and one and may as well have large dispersion. Parameters in such a marginal model are estimated using an extended version of the generalized estimating equations where the score vector is a nonlinear function of the observed response. The method is illustrated with an ophthalmology study on the use of intraocular gas in retinal repair surgeries.