Heart rate variability between hormone phases of the menstrual and oral contraceptive pill cycles of young women.

INTRODUCTION: The interplay between the sympathetic and parasympathetic branches of the autonomic nervous system contribute to adequate hemodynamic responses to stressors, reflected by the variation in intervals between heart beats, known as heart rate variability. The sex hormones estrogen and progesterone have been shown to affect autonomic function. The extent to which autonomic function may vary between different hormone phases of the natural menstrual cycle and how this relationship may differ in women taking oral contraceptives has yet to be fully elucidated. PURPOSE: To investigate differences in heart rate variability between the early follicular and early luteal phases of the menstrual cycle in naturally menstruating women and in oral contraceptive pill users. METHODS: Twenty-two young (22 ± 3 years), healthy women who were naturally menstruating or taking oral contraceptive pills participated in this study. Heart rate variability was measured at rest and during two sympathomimetic stressors: isometric handgrip exercise and cold pressor test. RESULTS: The proportion of successive NN intervals that differ by more than 50 ms was higher in oral contraceptive pill users during the placebo pill phase. Absolute high-frequency power was higher in the naturally menstruating women during the early luteal phase, relative to the early follicular phase. Other indices of vagal modulation were not different at rest or during sympathetic activation between hormone phases or groups. CONCLUSIONS: Vagal modulation may be increased in the early luteal menstrual cycle phase. Further,oral contraceptive use does not appear to adversely affect this modulation in young, healthy women.

Beverage Characteristics Perceived as Healthy among Hispanic and African-American Parents of Young Children.

BACKGROUND: It is recommended that children younger than 6 years of age avoid sugar-sweetened beverages (SSBs); yet, 25% of toddlers and 45% of preschool-aged children consume SSBs on a given day, with the highest intakes reported among Hispanic and African-American children. OBJECTIVE: To investigate characteristics that predominantly low-income Hispanic and African-American parents perceive to reflect a healthy beverage, and to examine the influence of these characteristics on parents' perceptions of the beverages they provide to their young children. DESIGN: This study consisted of two activities: a qualitative activity where parents (n = 102) were asked to report what characteristics they perceive to reflect a healthy beverage and a quantitative activity where parents (n = 96) indicated the extent to which each of the reported characteristics influence parents' perceptions of the beverages they provide to their young children. PARTICIPANTS AND SETTING: Hispanic and African-American parents of young children (younger than 6 years of age) were recruited from the District of Columbia metropolitan area. MAIN OUTCOME MEASURES: Beverage characteristics and influence scores. STATISICAL ANALYSES PERFORMED: Characteristics were categorized by the research team based on their perceived meaning. Perceived influence scores for each characteristic and category were compared across Hispanic and African-American parents using nonparametric, Mann-Whitney U tests, and false discovery rate adjustment was used to correct for multiple testing. RESULTS: The characteristics perceived to be most influential included those pertaining to perceived beverage sugar and sweetener content, being natural, and containing certain nutrients. Characteristics such as being homemade, made with fruit, and containing vitamins were reported to be more influential among Hispanic parents compared with African-American parents. CONCLUSIONS: Findings emphasize the need to address misperceptions about the healthfulness of beverages among Hispanic and African-American parents. Differences in the perceived influence of specific beverage characteristics across Hispanic and African-American parents underscore the importance of developing culturally relevant interventions to improve parents' beverage selection for their children.

Understanding Physical Activity Patterns Across the School Day in Urban Pre-Kindergarten and Elementary Schoolchildren.

PURPOSE: Despite recommendations that children accrue ≥60 min/day of moderate-to-vigorous physical activity (MVPA), numerous barriers may exist. We examined school-day MVPA patterns in lower-income children (pre-K to 5th grade) to determine whether they were meeting the minimum school-day guidelines of at least 30-min/day of MVPA and to identify opportunities for intervention. METHODS: Students (N = 629, pre-K-5th grade) from 4 urban schools wore Actigraph GT3X+ accelerometers over 2 school days. Mixed effects models evaluated sex- and grade-specific differences in MVPA and sedentary time. RESULTS: Only 34.6% of elementary and 25.3% of pre-K students met the school-time MVPA recommendation. Among elementary-aged children, boys accrued more MVPA than girls (30.8 ± 13.3 vs. 23.5 ± 10.7 min/day; p < 0.0001) with similar sex differences observed among pre-K children (51.3 ± 17.1 vs 41.9 ± 17.5 min/day; p < 0.001). Sedentary time also increased significantly with grade among elementary-aged children (207.9 ± 34.7 vs. 252.0 ± 36.1 min/day for those in 1st and 5th grade, respectively; p < 0.001), with girls accruing more sedentary time than boys (242.5 ± 48.2 vs. 233.8 ± 46.8 min/day; p < 0.0001). CONCLUSION: MVPA declines across elementary school years, with sex disparities observed as early as pre-K. Extended sedentary bouts and clustering of activity highlight opportunities for more movement throughout the school day.

Feasibility and acceptability of a randomized controlled trial to investigate withdrawal symptoms in response to caffeinated sugary drink cessation among children.

BACKGROUND: Sugary drinks (SDs) are key contributors to excess added sugar intake and the predominant source of caffeine among children. Chronic caffeine intake causes dependence, and evidence for sugar dependence is emerging. Development of withdrawal symptoms may pose an obstacle to SD cessation among children. We examined the feasibility and acceptability of a three-arm randomized controlled trial (RCT) designed to investigate withdrawal symptoms resulting from replacement of children's usual caffeinated SD intake with either caffeine-free alternatives or caffeine-free and sugar-free alternatives, compared with continued consumption of caffeinated SDs. METHODS: Twenty-nine children 8-12 years old, who consumed ≥12 ounces caffeinated SDs daily, enrolled. The two-week RCT required three in-person meetings and daily completion of electronic questionnaires to assess withdrawal symptoms and intervention adherence. Children were randomized to replace their usual caffeinated SD consumption with 1) caffeine-free alternatives, 2) caffeine-free and sugar-free alternatives, or 3) caffeinated SDs (control), provided by the study team. Feasibility and acceptability were assessed quantitatively and qualitatively. RESULTS: Twenty-eight participants (97%) completed the study. Adherence was high, with 73% reporting compliance with beverage assignments, and 76% completing all questionnaires. In qualitative interviews at follow-up, children described feelings of importance and commitment, and parents did not find the procedures to be overly burdensome. While challenges to adherence were reported (e.g., child wanting other SDs, time commitment), participants described innovative strategies (e.g., designating a place for study drinks in the refrigerator) to maintain adherence. CONCLUSION: Results indicated high levels of RCT feasibility and acceptability. The reported barriers and strategies for adherence will inform modifications required to design a larger and longer-term trial investigating withdrawal symptoms after SD cessation in children.

SODA MAPS: A Framework for Understanding Caffeinated Sugary Drink Consumption Among Children.

Excess sugary drink (SD) consumption is associated with childhood obesity and development of cardiometabolic disease. In addition to having high added sugar content, many SDs also contain caffeine, which may further encourage excess SD consumption among children. The objective of this study was to develop a conceptual framework of children's caffeinated SD consumption using group concept mapping, an applied social research multimethodology that collectively harnesses qualitative and quantitative data from participants to generate a visual representation of their ideas and input. Children, 8-14 years old, who reported consuming ≥12 ounces of caffeinated SDs (e.g., sodas, sweet teas) per day were recruited throughout Washington, D.C. and invited to participate. Concept mapping included three participant-driven activities: (1) brainstorming (n = 51), during which children reported reasons for their SD consumption, from which 58 unique reasons were identified; (2) sorting (n = 70), during which children sorted each of the reported reasons into categories and named each category; and (3) rating (n = 74), during which children rated the influence of each reason on their own caffeinated SD consumption. Similarity matrices, multidimensional scaling, and hierarchical cluster analysis were used to generate concept maps (hereafter "SODA MAPS"), which display the 58 reasons organized within eight overarching clusters. Among these eight clusters, Taste and Feel, Something to Do, and Energy were rated as particularly influential. Children's caffeinated SD consumption is encouraged not only by the palatable taste and reported preferences for these beverages (e.g., Taste and Feel), but also by psychological (e.g., Mood and Focus), biological (e.g., Energy), social (e.g., Something to Do) and environmental reasons (e.g., Nothing Better Available). Thus, the SODA MAPS can inform the development of tailored, multi-level SD reduction interventions that incorporate strategies to address important and currently overlooked reasons for caffeinated SD consumption among children.

SWEET MAPS: A Conceptualization of Low-Calorie Sweetener Consumption Among Young Adults.

BACKGROUND: The extent to which low-calorie sweeteners (LCSs) are helpful or harmful for weight management and metabolic health is unclear, because LCS effects may depend on the context in which they are consumed. OBJECTIVE: To develop a conceptual framework for LCS consumption. METHODS: Young adults ages 18-35 y, who reported LCS consumption, were recruited from a private, urban, university in the mid-Atlantic United States. Concept mapping, a mixed-method approach was used to identify, organize, and quantify determinants of LCS consumption. First, participants (n = 68) identified reasons for their LCS consumption through brainstorming; content analysis of those reasons identified 37 specific determinants of LCS consumption. Second, participants (n = 93) sorted all 37 determinants conceptually. Third, participants (n = 97) rated the extent to which each of the 37 determinants was reflective of their own consumption. Similarity matrices, multidimensional scaling, and hierarchical cluster analysis produced a series of 2-dimensional concept maps (SWEET MAPS). RESULTS: The SWEET MAPS identified 37 determinants, organized within 8 factors reflective of 3 overarching motives: perceived health benefits, palatability, and accessibility of LCSs. At the determinant level, the most highly rated determinants that exceeded the boundary (rating >3.0) were: "I want something that tastes sweet," "I am trying to maintain/control my weight," "They contain fewer calories," "They are available," and "I want to save calories because I am eating a high-calorie meal." CONCLUSIONS: LCS consumption is a function of many inter-related determinants spanning biological, psychological, and social domains. The SWEET MAPS are an important and novel use of concept mapping methods that can be used to inform the design and interpretation of future studies evaluating LCS effects.