1,721,130 research outputs found
The associations between physical activity and antepartum and postpartum depression
Get PDFBackground: Depression is a disease of great public health concern as it is responsible for a significant amount of disability and morbidity, and millions of Americans are depressed in any given year. Antepartum and postpartum depression confer health risks for the mother and her family. Research has indicated that physically active individuals may be less likely to experience depression, however, few studies have used pregnancy and postpartum samples. Methods: Data from the third and postpartum phases of the Pregnancy, Infection, and Nutrition (PIN) Study were used to determine the association between moderate-to-vigorous physical activity (MVPA) and depressive symptoms among pregnant and postpartum women. The PIN3 Study was a prospective cohort of 2006 pregnant women in North Carolina enrolled between January 2001 and June 2005. The PIN Postpartum Study followed a subset of the PIN3 women with in-home visits at 3 and 12 months postpartum. Physical activity recall was assessed by telephone at 17-22 and 27-30 weeks' gestation of pregnancy and at 3 months postpartum. Self-reported depressive symptoms were assessed by the Center for Epidemiologic Studies-Depression Scale at <20 and 24-29 weeks' gestation, while postpartum depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale at both home visits. Results: Active women with <=2.67 hours/week of total MVPA at 17-22 weeks' gestation had almost half the odds of having high depressive symptoms at 24-29 weeks' gestation as compared to women with no MVPA. However, total MVPA at 3 months postpartum was associated with a doubling of the odds of elevated depressive symptoms at 12 months postpartum. Adult and child care and indoor household MVPA were associated with increased odds of elevated depressive symptoms in both pregnancy and postpartum. No benefit from recreational activity on depressive symptoms was found at any time point. No significant associations were found between MVPA and depressive symptoms when examining the association between MVPA during pregnancy and 3-month depressive symptoms. Conclusion: Associations between physical activity and depressive symptoms differ by domain of MVPA. Future studies with higher statistical power should explore potential differences by domain of physical activity
In utero environmental exposures and reproductive endpoints
Get PDFThe etiology of age at menarche, infertility, and endometriosis, three common reproductive outcomes is largely unknown. Environmental chemicals exhibiting endocrine disrupting behavior have recently been implicated in a number of reproductive disorders, however little research has been done to examine the potential effects of these chemicals on adult reproductive health when the woman is exposed in utero. This research focuses on the effects of exposure to cigarette smoke and diethylstilbesterol (DES) experienced in utero and three reproductive outcomes: age at menarche, infertility, and endometriosis. Using data from over 5,000 women enrolled in the National Cooperative DES and Adenosis Study (DESAD) and a subsequent follow-up we were able to ascertain in utero exposures from the mother and subsequent health outcomes from the daughters later in life. Overall, we found no suggestion for a delay or advance in age at menarche for women who were exposed in utero to tobacco smoke. Furthermore, we found null results for the associations between in utero tobacco smoke and self-reported infertility and endometriosis. This is in contrast to a few earlier studies which have found effects. We determined that women exposed in utero to DES had a 70% increase in the odds for developing endometriosis compared to women who were unexposed after controlling for age. We also used these data to determine whether self-reported age at menarche later in life is a reliable measure. Women were asked around the age of puberty to report their age at menarche, and they were queried on this same information approximately twenty years later. We found that self-report of age at menarche later in life is not reliable when exact age at menarche is required, but the reliability is good within a year of the first reported age at menarche. The only covariates slightly associated with discordant responses were young age (<30 years) at the time of the follow-up survey and originally reported late age at menarche (>14 years). These three papers add to a small body of literature and address critical data gaps regarding the potential effects of the intrauterine environment on later reproductive health. These findings stress the importance of limiting potentially harmful exposures to pregnant women, as health effects may not only be seen at birth, but also years into adulthood. Furthermore our finding with respect to DES highlights the possibility that other endocrine disrupting chemicals, both pharmaceutical and those found in our environment may have similar adverse reproductive effects
Measurement error of energy intake during pregnancy and its influence on the association between carbohydrate quality and fetal growth
Get PDFPopulation studies rely on self-reported dietary intake, which is subject to considerable measurement error. A growing body of literature has shown that subjects tend to underreport energy (food) intake, and that underreporting occurs more frequently in certain subgroups, such as women and overweight persons. Further, recent evidence has demonstrated that systematic reporting error in energy intake can seriously distort nutrient risk estimates. Maternal nutrition plays an important role for both the mother and fetus; however results on associations between diet and pregnancy outcomes thus far have been modest or non-existent. One reason may be systematic reporting bias in nutritional data, although very little is known about this error in pregnant populations. Adequate fetal growth is an important predictor of newborn complications, and also contributes to a wide array of health conditions in adolescence and adulthood. Maternal glucose is the main energy substrate for intrauterine growth. The glycemic index (GI) and glycemic load (GL) of dietary carbohydrate, has been shown to alter postprandial glucose and insulin concentrations among healthy pregnant women, and thus may alter glucose substrate levels available for the fetus. Despite this strong biological plausibility, research on the carbohydrate quality of maternal diet and fetal growth remains limited. This dissertation includes two analyses of data from participants in the third phase of the Pregnancy, Infection and Nutrition cohort study (PIN3). The first analysis indicates that measurement error in energy intake is prevalent during pregnancy with 32.8% and 12.9% of subjects reporting intakes that were implausibly low and high, respectively. This error also varied by several maternal characteristics including pregravid body size, which is an important predictor of many pregnancy outcomes. Therefore, determining the nature of measurement error in energy intake may help to improve dietary assessment methodology in reproductive studies and account for bias in the calculation of effect estimates. In the second analysis, no association was observed between carbohydrate quality and fetal growth among generally healthy pregnancies; a null finding that remained after exclusion of participants with implausible energy intakes. Strengths and limitations of this study and the current literature, as well as and recommendations for future research are noted
The interplay between hormones, lipids, and dietary intake: the BioCycle study
Get PDFBackground: Exogenous estrogens (i.e. hormone therapy and oral contraceptives) have been shown to affect the lipid profile, leading to the hypothesis that endogenous estrogens may have similar effects. However, the relationship between estrogens and lipoproteins is complex, especially given that cholesterol is the initial precursor for steroid biosynthesis and dyslipidemia has been associated with altered hormone levels and anovulation. The effects of baseline cholesterol levels on anovulation are also not well understood. As fiber intake lowers both estrogen and lipoproteins, it is unknown whether estrogen may mediate the effect of fiber among premenopausal women. Methods: The BioCycle study was a prospective cohort of 250 self-reported regularly menstruating women aged 18 to 44, followed for two menstrual cycles. Lipoprotein cholesterol and hormones were measured in serum collected at up to 16 visits timed using fertility monitors. Marginal structural models with inverse probability of exposure weights were used to model the associations of interest. Results: Estradiol was positively associated with HDL cholesterol in acute effects models, and inversely associated with total and LDL cholesterol and triglycerides in persistent effects models. Total cholesterol levels preceding the predicted time of ovulation were weakly associated with an increased risk of anovulation, and luteinizing hormone:follicle-stimulating hormone ratio, sex hormone binding-globulin, insulin, and acne were identified as significant predictors of anovulation. Fiber consumption at or above 22 g/day was associated with lower total and LDL cholesterol, independent of estrogen, however the controlled direct effect was reduced at high levels of estrogen. Conclusions: Our results support the hypothesis that estrogen exerts beneficial effects on lipoprotein cholesterol levels and sheds light into the timing of these effects. The more atherogenic lipid profile and endocrine characteristics indicative of hyperandrogenism among anovulatory women are indicative of a mild undiagnosed phenotype of polycystic ovary syndrome, however further research is needed to elucidate the biological mechanisms. The reduced controlled direct effects of fiber on cholesterol at higher estrogen levels suggest that estrogen decreases fiber's effect among premenopausal women. Cycle phase should be considered in the design and interpretation of studies in women of reproductive age due to estrogen's influence on many biological processes
Botanical Dietary Supplement Use among Hispanic/Latino Adults in the Hispanic Community Health Study/Study of Latinos: Comparison of a Diet- vs. Medication-based Survey
Get PDFBotanical supplement use is common in the United States, but its assessment is difficult among Hispanics/Latinos. This report documents the prevalence of botanical and non-vitamin non-mineral (NVNM) supplement use over a 30-day recall period in a sample of Hispanics/Latinos in the US as measured with two instruments. Dietary supplement assessment in the Hispanic Community Health Study/Study of Latinos included both a medication inventory and a nutrition-based dietary supplement interview, enabling a comparison of instruments across supplement categories. Additional supplements were captured from 24-hour dietary recalls. In addition, characteristics of botanical supplement users and their motivations for use were explored. The prevalence of dietary supplement use was substantially higher as measured in the dietary supplement interview as compared to the medication inventory: for total dietary supplements (40 vs. 26%, respectively), for NVNM supplements (25 vs. 13%), and botanicals (9 vs. 4%). Concordance between the two measures was fair-moderate by Cohen's Kappa (0.28 - 0.56). Estimates were sensitive to inclusion of botanical teas captured exclusively from 24-hour dietary recalls with increases in botanical supplement prevalence from 7 to 15% with their addition. After vitamins and minerals, the most prevalent supplement ingredients consumed were omega-3 fatty acids (9.7%), lutein (9.6%), and lycopene (10.5%). The prevalence of botanical supplement use varied across Hispanic/Latino background. Individuals with a self-reported Mexican, Central or South American background were more likely to use botanicals than individuals with a Dominican, Cuban, or Puerto Rican background. Other characteristics associated with botanical supplement use included age, income, and adoption of healthy lifestyle behaviors. The association of education with botanical supplement use was stronger for more rather than less acculturated individuals. Motivations for supplement use included treatment/prevention of health conditions and appearance enhancements. Botanical use prevalence varied by Hispanic/Latino background, but characteristics of botanical supplement users across backgrounds were similar to those in the general US population as were the types of botanical supplements captured. Results suggest that drivers of commercial botanical supplement consumption may not differ between Hispanics/Latinos and the non-Hispanic white population and indicate an interest in self-improvement. Clearly needed are better dietary supplement assessment strategies and standardization of categorization.Doctor of Philosoph
Maternal Physical Activity and Birth Outcomes
Get PDFBackground: Information on physical activity (PA) during pregnancy and subsequent maternal birth outcomes (such as cesarean rate, labor duration) is plentiful in the literature, but consensus among studies is lacking. Poor exposure analytic methods may be a source of conflicting results. Objective: To estimate associations between PA during pregnancy and maternal birth outcomes using appropriate statistical methods. Methods: Detailed 7-day PA recalls were administered to pregnant women at two time points: 17-22 and 27-30 weeks' completed gestation. Covariables and labor outcomes were obtained by a combination of self-administered questionnaires and medical record abstraction. Physical activity was treated in analyses as a continuous, non-linear variable. We analyzed separately 8 different exposures: total hours/week PA at each time point, hours/week moderate-to-vigorous PA (MVPA) at each time point; total hours/week recreational PA at each time point, and finally hours/week recreational MVPA at each time point. Outcomes included induction, labor duration, augmentation, operative vaginal delivery (OVD), cesarean birth, episiotomy, and laceration severity. Covariables for each model were selected using directed acyclic graphs (DAGs); variables in final models were chosen through backwards stepwise selection using analysis of deviance. Sensitivity analyses explored the effects of excluding women reporting extremely large PA volumes and of excluding women reporting zero hours/week PA. Results: Physical activity during pregnancy was associated with a decreased risk of induction. Recreational PA at the second time point only was associated with a decreased risk of augmentation. PA during pregnancy was associated with longer labor durations, but our measure of labor duration was crude and we do not consider this result definitive. PA was not associated in these data with episiotomy, OVD, or cesarean. PA may be associated with increased laceration severity, but effects were quite small. Conclusions: Lack of consensus in the literature on the associations between PA and maternal birth outcomes may be partially because of categorical treatment of the exposure and lack of attention to gestational age at time of exposure
The effects of maternal prepregnancy body mass index and psychological factors on infant feeding behaviors
Get PDFThe American Academy of Pediatrics recommends exclusive breastfeeding for 6 months with continued breastfeeding until at least 1 year of age. Three-quarters of women in the U.S. initiate breastfeeding but rates decline considerably by 6 and 12 months postpartum; furthermore, many women introduce complementary foods before the recommended age. Low breastfeeding rates and early introduction of foods may be explained, in part, by the rise in obesity among women of childbearing age. There is some evidence that women who enter pregnancy overweight and obese are more likely to not breastfeed, to breastfeed for a shorter duration and to introduce complementary foods earlier than women of normal body mass index (BMI). It is unclear why this association exists but possible reasons include obesity-related biological changes, psychological changes and mechanical difficulties. The purpose of this research was to determine the association between pregravid BMI and infant feeding behaviors and explore whether the relationship was mediated by psychological factors present during pregnancy (depressive symptoms, stress, anxiety, and self-esteem). Data came from the postpartum component of the Pregnancy, Infection, and Nutrition study. Pregnant women, recruited from the University of North Carolina hospitals between January 2001 and June 2005, were followed from pregnancy to postpartum. Using multivariable regression analysis, we found that women who entered pregnancy overweight or obese were less likely to adhere to current infant feeding recommendations. Specifically, overweight or obese women were less likely to initiate breastfeeding; more likely to breastfeed for shorter duration (any or exclusive); and more likely to introduce complementary foods before 4 months of age compared to women of normal BMI. We did not find evidence to support the hypothesis that the association between pregravid BMI and infant feeding was mediated by psychological factors. Our results showed a strong association between maternal pregravid BMI and infant feeding behaviors but, contrary to our expectations, we did not find evidence for a mediatory psychological pathway. This suggests that other factors may be more important in explaining the pregravid BMI-infant feeding relationship. Future studies need to explore why overweight and obese women are less likely to adhere to infant feeding guidelines
The Effects of Maternal Prepregnancy Body Mass Index and Gestational Weight Gain on Offspring Anthropometric Outcomes
Get PDFRates of childhood overweight and obesity have increased over the past several decades. Numerous studies show that obesity during childhood is strongly associated with obesity in adolescence and adulthood, as well as the development of chronic conditions. Maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) represent modifiable behavioral factors that may influence the development of offspring body composition later in life; however, there are relatively few studies that examine these associations, especially for GWG. We used data from a recent prospective, longitudinal pregnancy cohort, the Pregnancy, Infection, and Nutrition Study (2001-2008), to examine the effects of prepregnancy BMI and GWG according to the 2009 Institute of Medicine (IOM) recommendations on offspring anthropometric outcomes within the first 3 years of life. Using multivariable regression analysis we found that the relative body size of infants at 6 months differs by maternal exposure. While both prepregnancy BMI and GWG were positively associated with weight-for-age z-scores (WAZ), only GWG was associated with length-for-age z-scores (LAZ). Prepregnancy overweight/obesity and excessive GWG[greater than or equal to]200% of the IOM recommendations were associated with higher weight-for-length z-scores (WLZ). At 3 years, children of overweight/obese mothers had significantly higher BMI z-scores and increased risk of overweight and obesity ([greater than or equal to]85th percentile and [greater than or equal to]95th percentile, respectively). Children of mothers with excessive GWG also had significantly higher BMI z-scores but only GWG[greater than or equal to]200% of the IOM recommendations was associated with an increased risk of obesity. Results from longitudinal analysis between birth and 3 years were consistent with these findings and revealed higher rates of change in WAZ and WLZ associated with prepregnancy obesity and higher rates of change in WAZ and LAZ with GWG[greater than or equal to]200% of the IOM recommendations. Children of overweight/obese women and women with GWG[greater than or equal to]200% of the IOM recommendations had distinctly higher predicted mean values of WAZ and WLZ that persisted across the study period compared to women in the lower prepregnancy BMI and GWG categories, respectively. These findings suggest a need for intervention efforts that reach women during their reproductive years, prior to becoming pregnant, to decrease fetal exposure to maternal overweight/obesity and excessive GWG
Classes of Physical Activity: Associations with Sociodemographic Characteristics and Risk Factors for the Metabolic Syndrome
Get PDFThe last several decades have produced a substantial body of literature indicating the health benefits of physical activity, including reduced risk of all-cause mortality, coronary heart disease (CHD), and CHD risk factors. Nevertheless, the prevalence of physical activity in the United States (US) continues to be suboptimal for most as work and daily activities become more and more sedentary. Concurrently, in 2004, 32.2% of adults were classified as obese as defined by a body mass index [greater than or equal to] 30 kg/m2. These two factors (obesity and physical inactivity) along with genetic factors are the primary root causes of the metabolic syndrome. Associations are well established between physical activity and hypertension, diabetes, obesity, triglycerides and high-density lipoproteins, all components of the metabolic syndrome. However, many of these associations may be somewhat transient in nature. Given this, those who demonstrate regular activity patterns across a seven day week would be associated cross-sectionally with fewer diagnoses of the metabolic syndrome compared with irregular activity. Therefore, the purpose of this analysis is to employ latent class analysis (LCA) to determine which activity patterns exist in the US, which sociodemographic characteristics are associated with these patterns, and finally whether certain patterns are disproportionately associated with any of the risk factors for the metabolic syndrome. The results indicate that a very large portion of the US population may be classified into patterns of physical activity that represent low levels of physical activity throughout the week. A weekend warrior class emerged for approximately 1% of the population. Both gender and age emerged as significant predictors of class membership. Mexicans, other Hispanics, and blacks all had higher odds of being in the most active class. Accumulating the recommended amount of physical activity for a week was consistently associated with positive profiles of the risk factors related to the metabolic syndrome, and accumulating substantially more physical activity was even better. However, the manner in which you accumulate this activity, either spread over many days of the week or compressed into just a couple, may have similar associations with the risk factors for the metabolic syndrome as well as the syndrome itself
Risk Factors Associated With the Presence And Severity Of Food Insecurity In Rural Honduras
Get PDFFood insecurity—the degree to which a household has limited access to or limited availability of food due to financial constraints—is a problem for many households in low- to middle- income countries and threatens the health and well-being of millions of people, especially children. The degree to which food insecurity affects individuals within a household may be related to factors that are known to protect against food scarcity and the presence of known factors that negatively contribute to a household’s food availability. The factors that are associated with household food insecurity may be different across various contexts. Knowledge of these factors is important to understand in the effort towards designing effective public health interventions to curb household food insecurity. In this paper, I performed a literature review using MEDLINE/PubMed to examine the risk factors associated with household food insecurity within developing countries around the world and to characterize the degree to which food insecurity was seen to correlate with anthropometric measurements within these different study contexts. In this review, I found that maternal education and household income are among the most common risk factors for food insecurity. Also, food insecurity and obesity—rather than under- nutrition—appear to be correlated in studies conducted in developing countries with transitioning economies, especially among women. This observation could reflect the ‘nutrition transition’ that has been observed in many developed as well as developing countries. In the second part of this paper, I describe a research project examining risk factors for household food insecurity in rural Honduras. This study confirmed results of the literature review, determining that maternal education and, to a lesser extent, maternal age were associated with household food insecurity. This information may help contribute to public health program planning. These factors can also be used to screen and identify families at risk for food insecurity and hunger in this study setting.Master of Public Healt
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