Direct and indirect effects of adiposity on markers of autonomic nervous system activity in older adults.

Several cardiovascular disease (CVD) risk factors (e.g., hypertension, poor glycemic control) can affect and be affected by autonomic nervous system (ANS) activity. Since excess adiposity can influence CVD development through its effect on hypertension and diabetes mellitus, it is important to determine how adiposity and altered ANS activity are related. The present study employed structural equation modeling to investigate the relation between adiposity and ANS activity both directly and indirectly through biological variables typically associated with glycemic impairment and cardiac stress in older adults. Utilizing the Atherosclerosis Risk in Communities (ARIC) dataset, 1,145 non-smoking adults (74±4.8 yrs, 62.8% female) free from known CVD, hypertension, and diabetes and not currently taking beta-blockers were evaluated for fasting blood glucose (FBG), insulin, and HbA1c concentrations, waist circumference (WC), blood pressure (BP), and markers of ANS activity. WC was recorded just above the iliac crest and was used to reflect central adiposity. Resting 2-minute electrocardiograph recordings, pulse wave velocity, and ankle-brachial index data were used to assess the root mean square of successive differences in RR intervals (RMSSD) and the pre-ejection period (PEP), markers of parasympathetic and sympathetic activity, respectively. FBG, insulin, and HbA1c inferred a latent variable termed glycemic impairment (GI), whereas heart rate and diastolic BP inferred a latent variable termed cardiac stress (CS). The structural equation model fit was acceptable [root mean square error of approximation = 0.050 (90% CI = .036, .066), comparative fit index = .970, Tucker Lewis Index = 0.929], with adiposity having both significant direct (ß = 0.208, p = 0.018) and indirect (ß = -.217, p = .041) effects on PEP through GI. Adiposity displayed no significant direct effect on RMSSD. CS displayed a significant pathway (ß = -0.524, p = 0.035) on RMSSD, but the indirect effect of WC on RMSSD through CS did not reach statistical significance (ß = -0.094, p = 0.137). These results suggest that adiposity's relation to ANS activity is multifaceted, as increased central adiposity had opposing direct and indirect effects on markers of sympathetic activity in this population of older adults.

Associations among eating behaviors, food security status, and dietary intake during pregnancy.

Dietary intake of certain food groups and/or nutrients during pregnancy has been associated with maternal and infant pregnancy-related outcomes. Few studies have examined how behavioral and environmental factors interact to influence prenatal diet. We examined associations between eating behaviors (dietary restraint, emotional eating, external eating) and food security status regarding dietary intake of selected nutrients/food groups during pregnancy. Participants (N = 299; 29% Non-Hispanic Black; 16% ≤ high school education; 21% food insecure) completed validated questionnaires to assess estimated daily intake of food groups/nutrients during pregnancy [e.g., added sugars from sugar-sweetened beverages (SSBs), % of energy from fat, fruit and vegetable (FV) intake] via National Cancer Institute Dietary Screener Questionnaires); eating behaviors (Dutch Eating Behavior Questionnaire); and food security status (6-item USDA Food security Module). Separate hierarchical multiple regressions for each dietary outcome were conducted controlling for maternal age, education, income-to-needs, race/ethnicity, pre-pregnancy BMI, and gestational diabetes. A significant interaction was found between dietary restraint and food security status on added sugar intake from SSBs (ß = -0.15, p = 0.02). The negative association between restraint and added sugar from SSBs was stronger among food insecure participants (ß = -0.47, p < 0.001 vs. ß = -0.15, p = 0.03). Higher external eating (ß = 0.21, p < 0.01) and lower restraint (ß = -0.13, p = 0.03) were associated with higher % of energy from fat and living in a food insecure household (ß = -0.15, p = 0.01) was associated with lower FV intake. Understanding dietary intake during pregnancy requires consideration of the broader context in which eating behaviors occur.

Maternal Depressive Symptoms and Adolescents' Unhealthy Behavior: A 15-year Longitudinal Study.

OBJECTIVES: First, to leverage 15 years of longitudinal data, from child ages 2 to 17, to examine whether maternal depressive symptoms in early and middle childhood and in adolescence predict their child's unhealthy behaviors during adolescence. Second, to examine whether the timing of maternal depressive symptoms or specific unhealthy behaviors matter and whether child depressive symptoms and body mass index explain these associations. METHODS: Data came from a prospective-longitudinal community sample with multi-informant data (N = 213) from child ages 2 to17. A cumulative adolescent unhealthy behavior index was calculated, summing the presence of poor sleep, poor diet, physical inactivity, sedentary behavior, and smoking. Regression analyses examined associations of maternal depressive symptoms in early childhood (ages 2 to 5), middle childhood (ages 7 to 10), and adolescence (age 15) with adolescents' unhealthy behaviors (ages 16 to17). Indirect effects of child depressive symptoms and body mass index were tested using a path model. RESULTS: Adolescents' unhealthy behaviors were common (eg, 2 out of 3 engaged in at least 1 unhealthy behavior). Higher levels of maternal depressive symptoms in middle childhood and adolescence were associated with adolescent engagement in more unhealthy behaviors at ages 16 to 17. Maternal depressive symptoms in early childhood were associated with adolescent unhealthy behaviors through indirect effects involving children's depressive symptoms and continuity of maternal depressive symptoms. CONCLUSIONS: Maternal depressive symptoms are associated with the number of adolescent unhealthy behaviors, both directly and indirectly. Promoting mothers' mental health can be crucial for promoting children's health behaviors and health.

Testing a cascade model linking prenatal inflammation to child executive function.

Inflammation during pregnancy is beginning to be understood as a risk factor predicting poor infant health and neurodevelopmental outcomes. The long-term sequelae associated with exposure to prenatal inflammation are less well established. The current study examined associations between maternal inflammation during pregnancy, markers of infant neurodevelopment (general cognitive ability, negative affect, and sleep quality), and preschool executive function (EF) in a longitudinal sample of 40 African American mother-infant dyads. Mothers completed a blood draw in the third trimester of pregnancy to measure plasma levels of C-reactive protein (CRP) and pro-inflammatory cytokines (e.g., interleukin 6 [IL-6], tumor necrosis factor-alpha [TNF-α]). When infants were 6 months of age, we assessed general cognitive ability via the Bayley-III, negative affect via the Still-Face Paradigm, and sleep quality via actigraphy monitoring. When children were 4 years of age, we assessed their EF ability using four tasks from the EF Touch battery. Elevated levels of maternal CRP, IL-6, and TNF-α were associated with poorer infant general cognitive ability. Although there were no direct effects of prenatal inflammation on preschool EF, we observed an indirect relationship between IL-6 and preschool EF ability via infant general cognitive ability. Our findings suggest that prenatal inflammation may have long-lasting, cascading implications for child neurodevelopment. Implications of these findings for health disparities in women and children of color are discussed.

Work, physical activity, and metabolic health: Understanding insulin sensitivity of long-haul truck drivers.

BACKGROUND: Long-haul truck drivers are disproportionately exposed to metabolic risk; however, little is known about their metabolic health and the role of physical activity and other risk factors in metabolic outcomes. OBJECTIVE: This study compares truck drivers' insulin sensitivity, and associations between metabolic risk factors and insulin sensitivity, with those of the general population. METHODS: Survey, anthropometric, and biometric data were collected from 115 long-haul truckers, which were then compared to the general population data using the National Health and Nutrition Examination Survey (NHANES) dataset. The quantitative insulin sensitivity check index (QUICKI) was used to estimate insulin sensitivity. RESULTS: Truck drivers had lower QUICKI scores than the general population cohort. Sagittal abdominal diameter and exercise were predictive for QUICKI among combined cohorts. Waist circumference and perceived health were more predictive for QUICKI among truck drivers, and sagittal abdominal diameter and income were more predictive for QUICKI among the general population. CONCLUSIONS: Long-haul truckers appear to represent a subset of the general population regarding the impact of physical activity and other metabolic risk factors on QUICKI. Accordingly, comprehensive efforts which target these factors are needed to improve truckers' physical activity levels and other metabolic risks.

Diabetes risk status and physical activity in pregnancy: U.S. BRFSS 2011, 2013, 2015, 2017.

BACKGROUND: Pregnant women without complications are advised to engage in physical activity (PA) to mitigate adverse outcomes. Differences may exist among pregnant women of diverging diabetes status in meeting national PA recommendations. We sought to examine differences in aerobic activity (AA) and muscle strengthening activity (MSA) by diabetes risk status (DRS) among pregnant women in the United States. METHODS: The sample (n = 9,597) included pregnant women, age 18-44 years, who participated in the 2011, 2013, 2015, and 2017 Behavioral Risk Factor Surveillance System. Levels of DRS include: no diabetes (ND), high risk for diabetes (HRD) due to self-reported gestational diabetes or pre-diabetes, and overt diabetes due to self-reported, clinically diagnosed diabetes (DM). Odds ratios (ORs) and 95% confidence intervals (CI) for meeting PA recommendations were obtained. Covariates included age, race, education, household child count, alcohol consumption, and smoking status. RESULTS: Findings revealed that on average, DM had 46.5 fewer minutes of weekly AA compared to ND. Furthermore, a significantly lower OR (0.39; CI 0.19-0.82) for meeting both recommendations was observed in DM as compared to ND after adjustment. CONCLUSIONS: We observed that pregnant women with overt diabetes had a lower odds of engaging in PA, while those at high risk were similar in their PA engagement to ND. Future studies aimed at assessing determinants of PA behavior may help guide efforts to promote exercise in pregnant women with diabetes.

Rationale, design and methods for the RIGHT Track Health Study: pathways from childhood self-regulation to cardiovascular risk in adolescence.

BACKGROUND: Cardiovascular risk factors during adolescence-including obesity, elevated lipids, altered glucose metabolism, hypertension, and elevated low-grade inflammation-is cause for serious concern and potentially impacts subsequent morbidity and mortality. Despite the importance of these cardiovascular risk factors, very little is known about their developmental origins in childhood. In addition, since adolescence is a time when individuals are navigating major life changes and gaining increasing autonomy from their parents or parental figures, it is a period when control over their own health behaviors (e.g. drug use, sleep, nutrition) also increases. The primary aim of this paper is to describe the rationale, design and methods for the RIGHT Track Health Study. This study examines self-regulation as a key factor in the development of cardiovascular risk, and further explores health behaviors as an explanatory mechanism of this association. We also examine potential moderators (e.g. psychosocial adversities such as harsh parenting) of this association. METHOD/DESIGN: RIGHT Track is a longitudinal study that investigates social and emotional development. The RIGHT Track Health Study prospectively follows participants from age 2 through young adulthood in an effort to understand how self-regulatory behavior throughout childhood alters the trajectories of various cardiovascular risk factors during late adolescence via health behaviors. Individuals from RIGHT Track were re-contacted and invited to participate in adolescent data collection (~16.5, 17.5 and 18(+) years old). Individuals completed assessments of body composition, anthropometric indicators, fitness testing (via peak oxygen consumption), heart rate variability during orthostatic challenge, 7-day accelerometry for physical activity and sleep, 24-h dietary recalls, and blood analysis for biomarkers related to metabolic syndrome, inflammatory status and various hormones and cytokines. Individuals also completed extensive self-report measures on diet and eating regulation, physical activity and sedentary behaviors, sleep, substance use, medical history, medication use and a laboratory-day checklist, which chronicled previous day activities and menstrual information for female participants. DISCUSSION: Insights emerging from this analysis can help researchers and public health policy administrators target intervention efforts in early childhood, when preventing chronic disease is most cost-effective and behavior is more malleable.

Effects of Tai Chi Chuan on insulin and cytokine levels in a randomized controlled pilot study on breast cancer survivors.

BACKGROUND: Tai Chi Chuan (TCC) is an integrative medicine mind-body practice with a physical activity component that has positive effects on aerobic capacity, muscular strength, and quality of life among cancer survivors, similar to the effects elicited by other modes of moderate-intensity exercise. Inflammatory cytokines and insulin and insulin-related signaling molecules may contribute to weight gain and affect cancer recurrence rates and survival; exercise can curb cancer- and treatment-related weight gain, increase survival, and reduce levels of insulin and inflammatory cytokines. Despite knowing the beneficial effects of conventional exercise interventions on these mediators, little is known about the physiologic effects of TCC on these pathways in breast cancer survivors. METHODS: We assessed the effects of a 12-week, moderately intense, TCC intervention (n = 9) compared with a non-physical activity control (n = 10) consisting of psychosocial support therapy (PST), on levels of insulin, insulin-like growth factor (IGF)-1, insulin growth factor-like binding protein (IGFBP)-1, IGFBP-3, and cytokines interleukin (IL)-6, IL-2, and interferon (IFN)-γ in breast cancer survivors. RESULTS: Levels of insulin are significantly different in TCC and PST groups; levels remained stable in the TCC group but increased in the PST control group (P = .099). Bivariate analysis revealed novel and significant correlations (all r > 0.45, all P ≤ .05) of both decreased fat mass and increased fat-free mass with increased IL-6 and decreased IL-2 levels. CONCLUSIONS: This pilot study shows that TCC may be associated with maintenance of insulin levels and changes in cytokine levels that may be important for maintenance of lean body mass in breast cancer survivors.

Substrate utilization during and after exercise in mild cystic fibrosis.

PURPOSE: To determine substrate utilization and energy expenditure during maximal and submaximal exercise and recovery in adolescents with cystic fibrosis (CF) and healthy age-matched controls (C). METHODS: Ten clinically stable CF patients (four girls, six boys; age = 10-22 yr) were matched by body mass index, age, gender, and Tanner stage to healthy controls. Subjects completed VO(2peak) testing and submaximal exercise (20 min) on a cycle ergometer at a relative intensity of 50% VO2(peak) and at an absolute power output (PO). Metabolic parameters were assessed during exercise and recovery (20 min). RESULTS: Similar respiratory quotient (RQ) values occurred in both groups during maximal exercise and recovery, despite differences in the maximal PO [CF = 114 (60-180) W and C = 171 (105-280) W, P = 0.006], the total work completed [CF = 27 (9.0-54.3) kJ and C = 55 (25.3-126.5) kJ, P = 0.008], or the VO(2peak) value attained [CF = 30.6 (8.5-45.2) mL kg(-1) min(-1) and C = 40.6 (29-64.5) mL kg(-1) min(-1), P = 0.027]. Submaximal exercise at the same absolute PO resulted in similar RQ values during exercise and recovery despite higher heart rates and average VO2 [CF = 18.8 (9.3-28.7) mL kg(-1) min(-1) and C = 15.2 (6.5-20.1) mL kg(-1)min(-1), P = 0.031] values in CF adolescents, and submaximal exercise at the same relative intensity also resulted in similar RQ values despite significantly greater average PO in the C group [CF = 38.7 (12.3-80) W and C = 67.8 (25.5-140) W, P = 0.039]. Excess postexercise oxygen consumption (EPOC) was greater in CF [2.79 (1.14-5.24) L O2] than C [1.46 (0.56-2.80) L O2] after submaximal exercise at a fixed PO (P = 0.036) but not after the relative exercise bout. CONCLUSIONS: Habitual physical activity participation does not warrant adjustment of macronutrient intake ratios in adolescents with mild to moderate CF, but total caloric intake may need to be increased based on the level of EPOC and upon the intensity and the duration of the habitual activity.

Attitudes toward physical activity in adolescents with cystic fibrosis: sex differences after training: a pilot study.

This study compared the attitudes of 16 adolescents (8 males and 8 females) with cystic fibrosis (CF) toward exercise and physical activity (PA) before and after a 6-week exercise program. Although the boys and girls had similar ages (12-18 years), the boys were fitter and leaner and had higher pulmonary function. Subjects reported both positive exercise attitudes of self and perceived attitudes of parents/friends that remained essentially unchanged after strenuous training. Boys reported higher vigorous activities at baseline than girls, but all subjects increased participation in very hard PAs after training. Girls had small but nonsignificant increases in PA at each (mild-vigorous) level. Results emphasize that adolescents with a mild to moderate lung disease can significantly increase PA in a nursing intervention.

Effects of acute aerobic and anaerobic exercise on blood markers of oxidative stress.

The purpose of this study was to compare oxidative modification of blood proteins, lipids, DNA, and glutathione in the 24 hours following aerobic and anaerobic exercise using similar muscle groups. Ten cross-trained men (24.3 +/- 3.8 years, [mean +/- SEM]) performed in random order 30 minutes of continuous cycling at 70% of Vo(2)max and intermittent dumbbell squatting at 70% of 1 repetition maximum (1RM), separated by 1-2 weeks, in a crossover design. Blood samples taken before, and immediately, 1, 6, and 24 hours postexercise were analyzed for plasma protein carbonyls (PC), plasma malondialdehyde (MDA), and whole-blood total (TGSH), oxidized (GSSG), and reduced (GSH) glutathione. Blood samples taken before and 24 hours postexercise were analyzed for serum 8-hydroxy-2'-deoxyguanosine (8-OHdG). PC values were greater at 6 and 24 hours postexercise compared with pre-exercise for squatting, with greater PC values at 24 hours postexercise for squatting compared with cycling (0.634 +/- 0.053 vs. 0.359 +/- 0.018 nM.mg protein(-1)). There was no significant interaction or main effects for MDA or 8-OHdG. GSSG experienced a short-lived increase and GSH a transient decrease immediately following both exercise modes. These data suggest that 30 minutes of aerobic and anaerobic exercise performed by young, cross-trained men (a) can increase certain biomarkers of oxidative stress in blood, (b) differentially affect oxidative stress biomarkers, and (c) result in a different magnitude of oxidation based on the macromolecule studied. Practical applications: While protein and glutathione oxidation was increased following acute exercise as performed in this study, future research may investigate methods of reducing macromolecule oxidation, possibly through the use of antioxidant therapy.

Early detection of type 2 diabetes among older African Americans.

The purpose of this research was to determine whether a group of African Americans who had no diagnosis of type 2 diabetes had elevated blood glucose levels and other risk factors indicative of type 2 diabetes. A convenience sample of 20 African American adults 50 years and older participated in the pilot study. Participants were screened for elevated fasting capillary blood glucose levels and related risk factors such as hypertension, high cholesterol levels, and high body mass index. Frequency data indicated that at least 50% of participants had capillary glucose levels greater than 110 mg/dL. An overwhelming majority of the participants with elevated glucose levels had one or more other risk factors for type 2 diabetes. Evidence-based practice clearly indicates that an early detection and control of type 2 diabetes can prevent complications and also help prevent coronary artery disease.