Biomedical subjects

Anna Maria Siega-Riz

Publications and source records attributed to Anna Maria Siega-Riz.

At least 37 records · Page 2Linked to original sources

PubMed2004

Second trimester folate status and preterm birth.

OBJECTIVE: The purpose of this study was to show that maternal folate status during pregnancy may be related to preterm birth. STUDY DESIGN: Women were recruited at 24 to 29 weeks' gestation from 1995 to 2000 into the Pregnancy, Infection, and Nutrition Study. Those who completed an interview and a food frequency questionnaire, or provided a blood sample for radioassay of serum (n = 2026) and red blood cell (n = 1034) folate were included. RESULTS: Mean daily dietary folate intake was 463 microg (SD +/- 248). Intake </=500 microg was associated with increased preterm delivery (RR = 1.8, 95% CI 1.4-2.6) controlling for total energy intake. Serum folate levels <16.3 ng/mL and red blood cell folate levels </=626.6 ng/mL yielded adjusted risk ratios of 1.8 (95% CI 1.3-2.5) and 1.7 (95% CI 1.1-2.6), respectively. Patterns were similar for spontaneous and overall preterm birth. CONCLUSION: These results support the hypothesis that low folate levels during the second trimester of pregnancy are associated with an increased risk of preterm birth.

Adult↗

PubMed2004

The effect of participation in the WIC program on preschoolers' diets.

OBJECTIVE: To evaluate nutrient, food intake, and snacking behavior by participation in the WIC (Special Supplemental Nutrition Program for Women, Infants, and Children) program. STUDY DESIGN: Secondary data analysis of a nationally representative cross-sectional survey conducted by USDA in 1994 to 1996 and 1998. METHODS: Statistical analysis was performed correcting for sample design effects and weighting for children in two income groups (<130%, n=1772 and 130% to 185% of poverty, n=689). RESULTS: Among WIC participants, the prevalence of snacking was significantly lower (68%) compared with nonparticipants (72%) (chi(2)=5.9, P=.01). For those <130% of poverty, WIC had a beneficial effect on the intake of fat, carbohydrates, added sugar, and fruit from the total diet as well as on added sugar from snacks. These were independent of food stamp participation. For those with higher incomes, the beneficial effects were limited to added sugar, iron density, and fruit intake for the total diet. A similar significant effect of decreased added sugar intake from snacks was also seen. CONCLUSIONS: Our results are in line with previous research showing beneficial effects of WIC participation among preschoolers, primarily for nutrients targeted by the program. This study shows that the effect can reach beyond those targeted nutrients.

Child Nutritional Physiological Phenomena↗

PubMed2004

A cross-national comparison of lifestyle between China and the United States, using a comprehensive cross-national measurement tool of the healthfulness of lifestyles: the Lifestyle Index.

BACKGROUND: Extensive studies have revealed the importance of a healthy lifestyle and the role of each lifestyle factor in health. However, lifestyle factors have rarely been studied simultaneously. The authors propose an integrated approach to summarize total healthfulness of lifestyles and to enhance understanding of lifestyle patterns across countries. METHODS: The authors created an overall measure of lifestyle called the Lifestyle Index (LI), integrating diet, physical activity, smoking, and alcohol use to provide a global tool of monitoring healthfulness and patterns of lifestyles. Using the LI, the authors conducted a cross-national comparison between China (n = 8352) and the United States (n = 9750). RESULTS: The LI effectively reflected the healthfulness of lifestyle components in both countries. The mean of the LI scores was slightly higher in China than the US. Scores of diet quality, physical activity, and smoking were higher in China, but scores of alcohol behavior were higher in the US. Similar lifestyle patterns but different unhealthy behaviors were identified in these countries. CONCLUSIONS: An assessment of total healthfulness of lifestyles and a better understanding of lifestyle patterns across countries using the LI can provide practical guidance to developing and targeting public health promotion activities to improve global public health.

Adult↗

PubMed2004

Self-reported overweight and obesity are not associated with concern about enough food among adults in New York and Louisiana.

BACKGROUND: A causal relationship between hunger and obesity has been postulated. Two cross-sectional studies have found evidence to suggest an association between obesity and food insecurity among adult women, and a third study suggests an association between underweight and food insecurity among men. The purpose of this study was to investigate the association between concern about enough food and obesity in an adult population at the state level. METHODS: A cross-sectional analysis was conducted using 1999 data from the Behavioral Risk Factor Surveillance System (BRFSS), Social Context Module (n = 3,945). RESULTS: An 8.0% prevalence of concern about enough food was found in Louisiana, and an 11.8% prevalence was found in New York, and was positively associated with morbid obesity, RR = 2.20 (95% CI = 1.24, 3.90) and RR = 2.23 (95% CI = 1.30, 3.84), respectively. However, this association became nonsignificant after controlling for education, income, race/ethnicity, marital status, and general health. CONCLUSION: A very strong apparent relationship between concern about enough food and obesity could be entirely accounted for by the influences of socioeconomic variables. This emphasizes the need for longitudinal research studies using precise measures of weight, height, and food security.

Adult↗

PubMed2004

Proximity of supermarkets is positively associated with diet quality index for pregnancy.

OBJECTIVES: To investigate the association between distance to the closest supermarket and a composite measure of diet, the diet quality index for pregnancy (DQI-P) was constructed. METHODS: Data from the Pregnancy, Infection and Nutrition (PIN) cohort, a prospective study of determinants of preterm birth, were analyzed. Food frequency questionnaires were used to construct DQI-P which includes: servings of grains, vegetables, fruits, folate, iron and calcium intake, percentage of calories from fat, and meal pattern score. Street address of residence, supermarkets, grocery and convenience stores were geocoded. Participants with complete food frequency and address data were included (n = 918). Multinomial logistic regression was used to estimate the conditional association of food outlets on diet quality, controlling for confounders and using a robust variance estimator to account for clustering of neighborhood characteristics. RESULTS: Women living greater than 4 miles from a supermarket were more than twice the odds (adjusted odds ratio = 2.16; 95% confidence interval = 1.2, 4.0) of falling into the lowest compared to highest DQI-P tertile compared to women living within 2 miles of a supermarket, after controlling for individual characteristics, other food retail outlets. CONCLUSION: These findings suggest that proximity of food retail outlets influences the diet quality of pregnant women.

Adolescent↗

PubMed2004

High prepregnancy BMI increases the risk of postpartum anemia.

OBJECTIVE: To assess the independent effect of prepregnancy BMI on the risk of postpartum anemia. RESEARCH METHODS AND PROCEDURES: Pregnant women from North Carolina who enrolled in the Iron Supplementation Study at their first prenatal visit at <20 weeks gestation and who delivered a live infant were followed to the postpartum visit (n = 439). BMI had a curvilinear relation in the logit of postpartum anemia; therefore, a restricted quadratic spline with three knots at the inflection points was used to specify BMI. Multiple log binomial regression was used to quantify the relation between prepregnancy BMI and postpartum anemia after adjusting for maternal ethnicity/race, education, smoking, initial hemoglobin concentration, and prenatal iron supplementation. RESULTS: Prevalence of postpartum anemia was 19.1%. After adjusting for confounders, we found that risk of postpartum anemia was similar for women with BMI values from 17 to 24 compared with women with a BMI of 20. Adjusted relative risk increased as BMI increased from 24 to 38. Women with a BMI of 28 had approximately 1.8 times the postpartum anemia risk of a woman with a BMI of 20 (95% confidence interval 1.3, 2.5), and obese women with a BMI of 36 had approximately 2.8 times the risk (95% confidence interval 1.7, 4.7). DISCUSSION: These data suggest that high prepregnancy BMI substantially increases the risk of postpartum anemia. Postpartum anemia screening and iron supplementation of overweight and obese women may be warranted.

Adult↗

PubMed2004

Predictors of pregnancy and postpartum haemoglobin concentrations in low-income women.

OBJECTIVE: Pregnancy and postpartum iron status is of great public health importance, yet few studies have examined predictors of haemoglobin (Hb) concentration during this time. We identified predictors of Hb from 24 weeks' gestation until delivery and from 4 to 25 weeks postpartum. DESIGN: Blood was drawn as many as four times during care: at the initial visit, at 24-29 weeks' gestation, at delivery and postpartum. A longitudinal, multivariable linear regression model was used to predict Hb concentration. SETTING: A public health clinic in Raleigh, North Carolina. SUBJECTS: n=520 women who participated in the Iron Supplementation Study. RESULTS: Hb concentration at the previous blood draw, short stature, non-Hispanic white ethnicity/race, >12 years of education and smoking were positive predictors of pregnancy and postpartum Hb concentrations. Iron supplement use was a positive predictor, while inadequate weight gain and severe nausea/vomiting were negative predictors of gestational Hb. A high infant birth weight and postpartum haemorrhage were negative predictors of postpartum Hb. Pre-pregnancy body mass index had a slight positive relationship with gestational Hb, but had a strong negative relationship with postpartum Hb. The longitudinal model also confirmed the typical pattern of gestational Hb concentration. As the number of weeks between the initial visit and the 24- to 29-week visit increased, Hb at 24-29 weeks' gestation decreased. As gestational age increased from 24 weeks until delivery, Hb concentration increased as well. CONCLUSIONS: The predictors identified here could be used in clinical settings to target high-risk women for intervention.

Adult↗

PubMed2004

Eating at fast-food restaurants is associated with dietary intake, demographic, psychosocial and behavioural factors among African Americans in North Carolina.

OBJECTIVE: To examine associations of the frequency of eating at fast-food restaurants with demographic, behavioural and psychosocial factors and dietary intake in African American adults. METHODS: Self-reported data from a population-based cross-sectional survey of 658 African Americans, aged 20-70 years, in North Carolina. An 11-page questionnaire assessed eating at fast-food restaurants, demographic, behavioural and diet-related psychosocial factors, and dietary intake (fruit, vegetable, total fat and saturated fat intakes, and fat-related dietary behaviours). RESULTS: The participants were aged 43.9+/-11.6 years (mean+/-standard deviation), 41% were male, 37% were college graduates and 75% were overweight or obese. Seventy-six per cent reported eating at fast-food restaurants during the previous 3 months: 4% usually, 22% often and 50% sometimes. Frequency of eating at fast-food restaurants was positively associated with total fat and saturated fat intakes and fat-related dietary behaviours (P<0.0001) and inversely associated with vegetable intake (P<0.05). For example, mean daily fat intake was 39.0 g for usually/often respondents and 28.3 g for those reporting rare/never eating at fast-food restaurants. Participants who reported usual/often eating at fast-food restaurants were younger, never married, obese, physically inactive and multivitamin non-users (all P<0.01). Frequency of eating at fast-food restaurants was positively associated with fair/poor self-rated health, weak belief in a diet-cancer relationship, low self-efficacy for healthy eating, weight dissatisfaction, and perceived difficulties of preparing healthy meals and ordering healthy foods in restaurants (all P<0.05). Frequency of eating at fast-food restaurants did not differ significantly by sex, education, smoking, ability to purchase healthy foods or knowledge of the Food Guide Pyramid. CONCLUSIONS: Eating at fast-food restaurants is associated with higher fat and lower vegetable intakes in African Americans. Interventions to reduce fast-food consumption and obesity in African Americans should consider demographic and behavioural characteristics and address attitudes about diet-disease relationships and convenience barriers to healthy eating.

Adult↗

PubMed2004

Effect of macronutrient intake on the development of glucose intolerance during pregnancy.

BACKGROUND: Dietary intake influences glucose tolerance status, yet the relation between macronutrient intake and the development of glucose intolerance during pregnancy has not been adequately examined. OBJECTIVE: We examined the relation between macronutrient intake early in pregnancy and the development of glucose intolerance. DESIGN: Data are from 1698 women in the Pregnancy, Infection, and Nutrition Study. Dietary intake during the second trimester was assessed with a food-frequency questionnaire. Women were classified into 1 of 3 glucose categories: gestational diabetes mellitus (GDM), impaired glucose tolerance (IGT), and normal glucose tolerance. Multivariate logistic regression was used to calculate the relative risk of IGT and GDM, with adjustment for potential confounders. A series of models were specified to test alternate hypotheses about the relation of diet to risk of IGT or GDM. RESULTS: The overall prevalences of IGT and GDM in the cohort were 2.6% and 5.2%, respectively. The addition model showed that adding 100 kcal from carbohydrates to the diet was associated with a 12% decrease in risk of IGT and a 9% decrease in risk of GDM. The substitution model showed that substituting fat for carbohydrates (per each 1% of total calories) resulted in a significant increase in risk of both IGT and GDM [relative risk = 1.1 (95% CI: 1.02, 1.12) and 1.1 (1.02, 1.10), respectively]. Predicted probabilities of IGT and GDM were reduced by one-half with a 10% decrease in dietary fat and a 10% increase in carbohydrate. CONCLUSIONS: This study found an association between increased fat intake and the development of glucose abnormalities in pregnancy.

Adult↗

PubMed2004

Maternal prepregnancy overweight and obesity and the pattern of labor progression in term nulliparous women.

OBJECTIVE: To examine the effect of maternal overweight and obesity on labor progression. METHODS: We analyzed data from 612 nulliparous women with a term pregnancy that participated in the Pregnancy, Infection, and Nutrition Study from 1995 to 2002. The median duration of labor by each centimeter of cervical dilation was computed for normal-weight (body mass index [BMI] 19.8-26.0 kg/m2), overweight (BMI 26.1-29.0 kg/m2), and obese (BMI > 29.0 kg/m2) women and used as a measurement of labor progression. RESULTS: After adjusting for maternal height, labor induction, membrane rupture, oxytocin use, epidural analgesia, net maternal weight gain, and fetal size, the median duration of labor from 4 to 10 cm was significantly longer for both overweight and obese women, compared with normal-weight women (7.5, 7.9, and 6.2 hours, respectively). For overweight women, the prolongation was concentrated around 4-6 cm, whereas for obese women, their labor was significantly slower before 7 cm. CONCLUSION: Labor progression in overweight and obese women was significantly slower than that of normal-weight women before 6 cm of cervical dilation. Given that nearly one half of women of childbearing age are either overweight or obese, it is critical to consider differences in labor progression by maternal prepregnancy BMI before additional interventions are performed.

Body Mass Index↗

PubMed2004

Pregnancy-related weight gain--a link to obesity?

Past research on maternal weight gain during pregnancy has focused on determinants and consequences of inadequate weight gain with concerns for the health of the infant. However, with the rising prevalence of obesity among women of childbearing ages and the high proportion of women who are gaining in excess of recommendations, a shift in research focus must occur to include consideration of the mother's long-term health status. The few studies that have examined determinants of excessive weight gain and postpartum weight retention in this country were not comprehensive in assessing diet, physical activity and psychosocial factors and suffer from small sample sizes. Information is lacking concerning pregnant women's perceptions about eating and gaining weight, what they actually eat, how consumption and exercise relate to weight gain, and how psychosocial factors influence these behaviors during pregnancy. Likewise, little is known concerning these same attitudes and behaviors during the postpartum period that may contribute to weight retention.

Adult↗

PubMed2004

Psychosocial factors and preterm birth among African American and White women in central North Carolina.

OBJECTIVES: We assessed associations between psychosocial factors and preterm birth, stratified by race in a prospective cohort study. METHODS: We surveyed 1898 women who used university and public health prenatal clinics regarding various psychosocial factors. RESULTS: African Americans were at higher risk of preterm birth if they used distancing from problems as a coping mechanism or reported racial discrimination. Whites were at higher risk if they had high counts of negative life events or were not living with a partner. The association of pregnancy-related anxiety with preterm birth weakened when medical comorbidities were taken into account. No association with preterm birth was found for depression, general social support, or church attendance. CONCLUSIONS: Some associations between psychosocial variables and preterm birth differed by race.

Adaptation, Psychological↗

PubMed2004

Changes in diet quality of American preschoolers between 1977 and 1998.

OBJECTIVES: We determined diet quality trends among nationally representative samples of preschoolers between 1977 and 1998. METHODS: Adjusted diet quality index scores, overall intake, and tertiles of total score were compared for combined samples and 2 age groups using t tests with Bonferroni correction; surveys used were the US Department of Agriculture's National Food Consumption Survey 1977-1979 (n = 2342), Continuing Survey of Food Intake by Individuals (CSFII) 1989-1991 (n = 858), and CSFII 1994-1996 and 1998 (n = 5355). RESULTS: Total scores increased slightly. Consumption of grains, fruits, and vegetables improved while added sugar and juice intake worsened. CONCLUSIONS: Diet quality improved marginally since 1977. Consumption of fruits and vegetables needs to be increased and that of total and saturated fat, juice, and added sugar decreased.

Child Nutrition Sciences↗

PubMed2004

Poverty, education, race, and pregnancy outcome.

Few studies have considered the differing impact of socioeconomic factors on pregnancy outcomes among racial subgroups. We assessed pregnancy outcome by race, education, and income (poverty index), using data from the Pregnancy, Infection, and Nutrition Study, a cohort study of preterm birth in central North Carolina, using binomial regression. Poverty was associated with an increased risk of preterm birth only among African Americans with 12 or more years of education (RR=1.6, 95% CI: 1.1, 2.2). White participants with both a low level of education and an income below the poverty line were at increased risk of preterm birth (RR=1.7, 95% CI: 1.1, 2.7). White women with 12 or more years of education had increased risk of small-for-gestational-age birth (SGA, defined as <10th percentile of birth weight for gestational age) associated with poverty status (RR=1.7, 95% CI: 1.1, 2.7). Socioeconomic indicators appear to have complex joint effect patterns among racial subgroups, perhaps because the material and psychological implications of education and income status differ between groups.

Adult↗

PubMed2003

Who is leading the change?. U.S. dietary quality comparison between 1965 and 1996.

BACKGROUND: Many studies have examined rapidly changing trends in U.S. dietary intake, but not as they correspond to other health inequalities among black and white Americans. The purpose of this study was to explore 30-year trends in diet quality and to examine whether income or education is the key socioeconomic factor linked with these shifts. METHODS: The 1965 Nationwide Food Consumption Survey and the 1994-1996 Continuing Survey of Food Intake by Individuals were used and included, respectively, 6476 and 9241 respondents who were aged > or =18 years. The Revised Diet Quality Index (DQI-R), an instrument that provides a summary assessment of a diet's overall healthfulness, was also used. RESULTS: Between 1965 and 1996, improvements were found in both the overall DQI-R and its components across all education levels, with the exception of calcium intake. Conversely, improvements linked with income effects were inconsistent and less clear. In 1965, the effect of college attendance resulted in a 1.8 point higher DQI-R, higher calcium intake, and increased servings of fruits and vegetables. In 1994-1996, there were consistently improved diets for the overall DQI-R and its components, particularly among college attendees. CONCLUSIONS: Diet quality has improved across both race and socioeconomic status groupings between 1965 and 1994-1996; however, education provides a much clearer differentiation. Education efforts must be emphasized to eliminate disadvantages in diet quality.

Adolescent↗

PubMed2003

Vitamin C intake and the risk of preterm delivery.

OBJECTIVE: Ascorbic acid deficiency may lead to premature rupture of the membranes. STUDY DESIGN: The study included a prospective cohort of pregnant women, aged >/=16 years, with singleton gestations who received care at one of four prenatal clinics in central North Carolina from 1995 through 1998. Vitamin C intake preconceptionally and during the second trimester was examined for its association with preterm delivery and subsets of preterm labor, premature rupture of the membranes, and medical induction in 2064 women. RESULTS: Women who had total vitamin C intakes of <10th percentile preconceptionally had twice the risk of preterm delivery because of premature rupture of the membranes (relative risk, 2.2; 95% CI, 1.1, 4.5). This risk was attenuated slightly for second-trimester intake (relative risk, 1.7; 95% CI, 0.8, 3.5). The elevated risk of preterm premature rupture of the membranes was greatest for women with a low vitamin C intake during both time periods. CONCLUSION: Because diet and supplement use are modifiable behaviors, corroboration of these findings would suggest a possible intervention strategy.

Adolescent↗

PubMed2003

The Diet Quality Index-International (DQI-I) provides an effective tool for cross-national comparison of diet quality as illustrated by China and the United States.

A composite measure of diet has been preferred to an index of a single nutrient or food in the area of dietary assessment. However, the lack of such a tool for cross-national comparisons has restricted the ability to compare diet quality between countries using an overall measure of diet. In this study, we created a tool called the Diet Quality Index-International (DQI-I) for global monitoring and exploration of diet quality across countries. The major categories of the index components are variety, adequacy, moderation and overall balance. Using the tool, this research presents a cross-national comparison of diet quality between China and the United States, incorporating comparable national in-depth diet data. The mean of the DQI-I score was slightly higher in China than in the United States. By major categories of the DQI-I, dietary variety was better achieved in the U.S. diet; moderation and overall balance of intakes were better accomplished in China. The DQI-I was successful in capturing variability in intakes of food and nutrients in both countries. Some distinct patterns of poor quality diet in each country were also identified. As demonstrated in this study, the DQI-I provides an effective means of cross-national comparative work for global understanding of diet quality. Furthermore, the dietary problem areas identified by the DQI-I may be useful in guiding the development of programs to improve public health.

China↗

PubMed2003

Dietary supplement use in the context of health disparities: cultural, ethnic and demographic determinants of use.

Women of African American, Hispanic, Asian, Pacific Islander, Native American and Alaskan descent constitute 29% of the female population in the United States but they experience health problems disproportionately. Compared with white women as a group, they are in poorer health and use fewer health services. We know from recent studies that the daily use of multivitamins has been associated with lower risk of coronary disease, colon cancer and breast cancer, particularly for alcohol drinkers. In addition, daily multivitamin and multimineral usage by the elderly can reduce the number of days of illness due to infections by 50%. However, supplement use among women tends to be more prevalent among the middle and older age categories; white, well-educated and higher income women; and those residing in the western part of the United States. This examination of the current health disparities and usage patterns indicates that the women who could benefit most from supplements are not typical users. Qualitative data collected on iron and folic acid supplementation programs in developing countries indicate that diverse cultural practices, attitudes and beliefs among vulnerable populations may influence supplement use. However, data in the U.S literature that describe these factors by culture or ethnicity are sparse. If we are to promote dietary supplements to women who are most vulnerable, more research is warranted in the area of health beliefs, attitudes and sociodemographic determinants of supplement use by culture and or ethnicity, particularly among underprivileged groups.

Cultural Characteristics↗