• The CAPN2/CAPN8 Locus on Chromosome 1q Is Associated with Variation in Serum Alpha-Carotene Concentrations

      D'Adamo, C.R.; Dawson, V.J.; Ryan, K.A. (S. Karger AG, 2017)
      Background/Aims: Alpha-carotene is a provitamin A carotenoid present in fruits and vegetables. Higher serum concentrations of α-carotene have been associated with lower risk of cancer and all-cause mortality. Previous studies have suggested that genetic variants influence serum concentrations of provitamin A carotenoids, but to date no variants have been robustly associated with serum α-carotene concentrations. The aim of this study was to identify genetic associations with serum α-carotene concentrations using the genome-wide association study (GWAS) approach. Methods: A GWAS of serum α-carotene concentrations was conducted in 433 Old Order Amish adults who had consumed a 6-day controlled diet. Linear regression models adjusting for age, gender, and family structure were utilized to evaluate associations between genetic variants and serum α-carotene concentrations. Results: Genome-wide significant associations with α-carotene concentrations were observed for loci on chromosome 1q41 between the genes CAPN2 and CAPN8 (rs12137025, p = 3.55 × 10-8), chromosome 2p21 in PRKCE (rs2594495, p = 1.01 × 10-8), and chromosome 4q34 (rs17830069, p = 2.89 × 10-8). Conclusions: We identified 3 novel loci associated with serum α-carotene concentrations among a population that consumed a controlled diet. While replication is necessary, the CAPN2/CAPN8 locus provides compelling evidence for an association with serum α-carotene concentrations and may suggest a relationship with the development and progression of cancers. Copyright 2016 S. Karger AG, Basel.
    • A Food-Derived Dietary Supplement Containing a Low Dose of Iron Improved Markers of Iron Status Among Nonanemic Iron-Deficient Women

      D'Adamo, C.R.; Novick, J.S.; Feinberg, T.M. (Routledge, 2018)
      Objective: Iron deficiency is the most common nutrient deficiency in the world. While deficiency can often be resolved through dietary supplementation with iron, adverse events are common and frequently preclude compliance. The objective of this study was to determine whether a food-derived dietary supplement containing a low dose of iron and nutrients that increase iron absorption could resolve iron deficiency with fewer adverse events than reported at higher doses. Methods: A pilot clinical trial (NCT02683369) was conducted among premenopausal women with nonanemic iron deficiency that was verified by blood screening. Participants consumed a dietary supplement (Blood Builder®/Iron Response®) once daily for 8 weeks containing 26 mg of iron, vitamin C, folate, and other food-derived nutrients. Primary outcomes were markers of iron status (serum ferritin, hemoglobin, soluble transferrin receptor, total body iron stores) and secondary outcomes were self-reported fatigue and energy. All outcomes were assessed at baseline and 8 weeks. Adverse events were monitored with questionnaires, daily diaries, and contact with a physician. Dependent samples t test and Wilcoxon signed-rank test were used to analyze outcomes. Results: Twenty-three participants enrolled in the study. Iron deficiency was resolved in the sample (mean serum ferritin: baseline = 13.9 μg/L, 8 weeks = 21.1 μg/L, p < 0.001). All other markers of iron status, fatigue, and energy also improved during the study (p < 0.04). No adverse events were reported. Conclusions: While larger and controlled studies are needed to confirm these findings, a food-derived dietary supplement with a low dose of iron and absorption-enhancing nutrients resolved iron deficiency and improved all other markers of iron status without any adverse events. Copyright 2018 Christopher R. D'Adamo, James S. Novick, Termeh M. Feinberg, Valerie J. Dawson, and Larry E. Miller Copyright 2018, Copyright Christopher R. D'Adamo, James S. Novick, Termeh M. Feinberg, Valerie J. Dawson, and Larry E. Miller.
    • International ResearchKit App for Women with Menstrual Pain (Development, Access, and Engagement): Pragmatic Randomized Control Trial

      Wang, J.; D'Adamo, C.R.; Witt, C.M. (JMIR Publications, 2020)
      BACKGROUND: Primary dysmenorrhea is a common condition in women of reproductive age. A previous app-based study undertaken by our group demonstrated that a smartphone app supporting self-acupressure introduced by a health care professional can reduce menstrual pain. OBJECTIVE: This study aims to evaluate whether a specific smartphone app is effective in reducing menstrual pain in 18- to 34-year-old women with primary dysmenorrhea in a self-care setting. One group of women has access to the full-featured study app and will be compared with 2 control groups who have access to fewer app features. Here, we report the trial design, app development, user access, and engagement. METHODS: On the basis of the practical implications of the previous app-based study, we revised and reengineered the study app and included the ResearchKit (Apple Inc) framework. Behavior change techniques (BCTs) were implemented in the app and validated by expert ratings. User access was estimated by assessing recruitment progress over time. User evolution and baseline survey respondent rate were assessed to evaluate user engagement. RESULTS: The development of the study app for a 3-armed randomized controlled trial required a multidisciplinary team. The app is accessible for the target population free of charge via the Apple App Store. In Germany, within 9 months, the app was downloaded 1458 times and 328 study participants were recruited using it without external advertising. A total of 98.27% (5157/5248) of the app-based baseline questions were answered. The correct classification of BCTs used in the app required psychological expertise. CONCLUSIONS: Conducting an innovative app study requires multidisciplinary effort. Easy access and engagement with such an app can be achieved by recruitment via the App Store. Future research is needed to investigate the determinants of user engagement, optimal BCT application, and potential clinical and self-care scenarios for app use. TRIAL REGISTRATION: ClinicalTrials.gov NCT03432611; https://clinicaltrials.gov/ct2/show/NCT03432611 (Archived by WebCite at http://www.webcitation.org/75LLAcnCQ). Copyright The Authors.