Additive interactions of maternal prepregnancy BMI and breast-feeding on childhood overweight

OBJECTIVE: To examine the interactions of maternal prepregnancy BMI and breast-feeding on the risk of overweight among children 2 to 14 years of age. RESEARCH METHODS AND PROCEDURES: The 1996 National Longitudinal Survey of Youth, Child and Young Adult data in the United States were analyzed (n = 2636). The weighted sample represented 51.3% boys, 78.0% whites, 15.0% blacks, and 7.0% Hispanics. Childhood overweight was defined as BMI >/=95th percentile for age and sex. Maternal prepregnancy obesity was determined as BMI >/=30 kg/m(2). The duration of breast-feeding was measured as the weeks of age from birth when breast-feeding ended. RESULTS: After adjusting for potential confounders, children whose mothers were obese before pregnancy were at a greater risk of becoming overweight [adjusted odds ratio (OR), 4.1; 95% confidence interval (CI), 2.6, 6.4] than children whose mothers had normal BMI (<25 kg/m(2); p < 0.001 for linear trend). Breast-feeding for >/=4 months was associated with a lower risk of childhood overweight (OR, 0.6; 95% CI, 0.4, 1.0; p = 0.06 for linear trend). The additive interaction between maternal prepregnancy obesity and lack of breast-feeding was detected (p < 0.05), such that children whose mothers were obese and who were never breast-fed had the greatest risk of becoming overweight (OR, 6.1; 95% CI, 2.9, 13.1). DISCUSSION: The combination of maternal prepregnancy obesity and lack of breast-feeding may be associated with a greater risk of childhood overweight. Special attention may be needed for children with obese mothers and lack of breast-feeding in developing childhood obesity intervention programs.     

General obesity and central adiposity in a representative sample of Tehranian adults: prevalence and determinants

AIMS: To determine the prevalence and associations of general and central obesity in adults residing in district 13 of Tehran and to examine the associations of obesity with certain factors. DESIGN: Population-based cross sectional study. SETTING: Tehran, the capital of Iran. SUBJECTS: A total of 9984 subjects (4164 men and 5820 women) aged 20-70 years. METHODS: Demographic data were collected and anthropometric indices including weight, height, and waist and hip circumference were measured, according to standard protocols. Dietary intake was assessed by means of two 24-hour dietary recall forms. To determine the prevalence and association of general and central obesity, the suggested cut-off for Tehranian people, adjusted for their age group, was used. A body mass index (BMI) of > or =24 for men and > or =25 for women was used to determine the characteristic of obesity. Central obesity was determined as a waist-hip ratio (WHR) of > 0.86 for men and WHR > or = 0.78 for women. To determine the associations between general and central obesity and other factors, logistic regression was used. RESULTS: The means of BMI, waist circumference (WC), and WHR were 25.8 +/- 4.1 kg/m2, 88.3 +/- 11.4 cm, and 0.91 +/- 0.07 in men and 27.3 +/- 5.4 kg/m2, 87.5 +/- 12.9 cm, and 0.83 +/- 0.08 in women, respectively. Obesity and central obesity were higher in women than in men; 67% vs. 29% for obesity and 93% vs. 74.1% for central obesity, respectively. Illiteracy (OR = 1.65; 95% CI = 1.13-2.41 in men; OR = 1.87, 95% CI = 1.59-2.21 in women), marriage (OR = 3.84, 95% CI = 3.63-4.29 in men; OR = 3.20, 95% CI = 3.63-4.19 in women), and very low physical activity (OR = 1.35, 95% CI = 1.09-1.53 in men; OR = 1.39, 95% CI = 1.10-1.76 in women) were factors associated with obesity. The risk of being centrally obese for men in the fourth quartile of legumes intake was lower than men in other quartiles (p < 0.05). Women in the first quartile of dairy consumption had the highest risk of being generally and centrally obese (OR = 2.16, 95% CI = 1.72-2.48 for general obesity and OR = 3.01, 95% CI = 2.36-3.67 for central obesity). The risk of obesity for women in the fourth quartile of energy and saturated fatty acid consumption was higher than for those in the first quartile (OR = 2.69, 95% CI = 2.39-3.11 for energy and OR = 1.36, 95% CI= 1.10-1.64 for saturated fatty acids). The risk of being centrally obese was higher for women in the first quartile of protein intake compared with women in the fourth quartile (OR = 1.71, 95% CI = 1.02-2.32). CONCLUSIONS: The results from this national population-based study in Iran show high prevalence of obesity in Tehranian adults. The strong associations between obesity and certain life style factors confirm the necessity of multifactorial intervention.     

Familial risk of overweight and obesity in the Canadian population using the WHO/NIH criteria

OBJECTIVE: To determine the familial risk of overweight and obesity in Canada. RESEARCH METHODS AND PROCEDURES: The sample was comprised of 15,245 participants from 6377 families of the Canada Fitness Survey. The risk of overweight and obesity among spouses and first-degree relatives of individuals classified as underweight, normal weight, pre-obese, or obese (Class I and II) according to the WHO/NIH guidelines for body mass index (BMI) was determined using standardized risk ratios. RESULTS: Spouses and first-degree relatives of underweight individuals have a lower risk of overweight and obesity than the general population. On the other hand, the risk of Class I and Class II obesity (BMI 35 to 39.9 kg/m2) in relatives of Class I obese (BMI 30 to 34.9 kg/m2) individuals was 1.84 (95% CI: 1.27, 2.37) and 1.97 (95% CI: 0.67, 3.25), respectively, in spouses, and 1.44 (95% CI:1.10, 1.78) and 2.05 (95% CI: 1.37, 2.73), respectively in first-degree relatives. Further, the risk of Class II obesity in spouses and first-degree relatives of Class II obese individuals was 2.59 (95% CI: -0.91, 6.09) and 7.07 (95% CI: 1.48, 12.66) times the general population risk, respectively. DISCUSSION: There is significant familial risk of overweight and obesity in the Canadian population using the BMI as an indicator. Comparison of risks among spouses and first-degree relatives suggests that genetic factors may play a role in obesity at more extreme levels (Class II obese) more so than in moderate obesity.     

Comorbidity of overweight and obesity in a nationally representative sample of German adults aged 18-79 years

ABSTRACT: BACKGROUND: Overweight has increased in many countries over the past 20 years and excessive body weight is an established risk factor for adverse health outcomes and chronic diseases. This study aimed to determine comorbidity associated with overweight and obesity in a nationally representative sample of German adults. METHODS: In the German National Health Interview and Examination Survey 1998 standardized measures of body weight, height and waist circumference (WC) were obtained for 7,124 men and women 18 to 79 years of age. Information on pre-existing health conditions, health-related behaviors, and sociodemographic characteristics was collected using physician-administered computer-assisted interviews and self-administered questionnaires. World Health Organization (WHO) cut-off criteria were applied to define overweight (BMI: 25.0-29.9 kg/m2) and obesity (BMI [GREATER-THAN OR EQUAL TO]30.0 kg/m2) and abdominal obesity (men: WC [GREATER-THAN OR EQUAL TO]102 cm; women: WC [GREATER-THAN OR EQUAL TO]88 cm). RESULTS: The crude prevalence of persons with cardio metabolic risk factors, diabetes mellitus, cardiovascular disease (CVD), gall bladder disease, and osteoarthritis showed a significant stepwise increase from the lowest to the highest BMI category in both sexes. In multiple logistic regression models adjusting for age, social status, and smoking, significant associations with overweight and obesity persisted for cardio metabolic risk factors and osteoarthritis. For example, obese persons had a three- to fourfold higher chance of having any cardio metabolic risk factor compared to normal weight persons (odds ratio (OR) = 4.07, 95% CI: 3.16-5.25 for men; OR = 3.40 (2.60-4.46) for women). Only in women, overweight and obesity as well as abdominal obesity, independent of BMI category, were significantly and consistently associated with diabetes (overweight: OR = 1.85 (1.03-3.30); obesity: OR = 2.94 (1.63-5.31); abdominal obesity: OR = 1.44 (1.08-1.92) and gall bladder disease (overweight: OR = 1.65 (1.22-2.25); obesity: OR = 3.06 (2.26-4.14); abdominal obesity: OR = 1.73 (1.25-2.39)). CONCLUSION: Current estimates of disease burden underline the public health importance and clinical relevance related to overweight and obesity and needs to take into account comorbidity aspects.     

Maternal pre-pregnancy overweight and obesity and the risk of cesarean delivery in nulliparous women

PURPOSE: To examine the effect of maternal pre-pregnancy overweight and obesity on the risk of term cesarean delivery in nulliparous women. METHODS: The authors examined data from 641 nulliparous women with a term pregnancy that participated in the Pregnancy, Infection, and Nutrition Study from 1995 to 2002. Unadjusted and adjusted risk ratios and 95% confidence intervals (CI) were computed for normal weight (BMI 19.8-26.0 kg/m(2)), overweight (BMI 26.1-29.0 kg/m(2)), and obese (BMI>29.0 kg/m(2)) women. Normal weight women served as the referent population. RESULTS: The unadjusted risk ratio for cesarean delivery for overweight women compared with normal weight women was 1.4 (95% CI, 0.97, 2.1) and for obese women compared with normal weight women was 1.4 (95% CI, 1.03, 2.0). After controlling for maternal height, education, weight gain during pregnancy, and labor induction, the adjusted risk ratio for cesarean delivery among overweight women was 1.2 (95% CI, 0.8, 1.8). The adjusted risk ratio for obese women was 1.5 (95% CI, 1.05, 2.0). CONCLUSION: Our analysis confirms that there is a moderate association between maternal pre-pregnancy obesity and an unplanned term cesarean delivery. However, the risk is not as large as previously reported.     

Obesity, overweight and patterns of osteoarthritis: the Ulm Osteoarthritis Study

The objective of this study was to assess the association between obesity and osteoarthritis (OA) of the knee, hip, and hand. OA patterns were studied in 809 patients with knee or hip joint replacement due to OA. Patients with OA were categorized as having bilateral or generalized OA according to the presence of radiographic OA in the contralateral joint or different finger joints, and as normal weight, overweight, or obese according to their body mass index (BMI). Odds ratios (OR) and 95% confidence intervals (CI) for relative weight and OA patterns were estimated with multivariable logistic regression. Eighty-five percent of participants had bilateral OA, 26% had generalized OA, and 31% were obese. Obesity (BMI >/= 30 kg/m(2); OR = 8.1; 95% CI: 2.4-28) and overweight (BMI >/= 25 kg/m(2); OR = 5.9; 95% CI: 2.0-18) were strongly associated with bilateral knee OA. No association between obesity and bilateral hip OA (OR = 0.7; 95% CI: 0.3-1.7) nor generalized OA (OR = 1.1; 95% CI: 0.6-2.1) was observed. Obesity seems to be a mechanical rather than a systemic risk factor for OA with the knee joint being especially susceptible.     

Causes of death in obesity: relevant increase in cardiovascular but not in all-cancer mortality

BACKGROUND AND OBJECTIVE: To assess the relation between body mass index (BMI) and the risk of death from various causes in a prospective cohort study. METHODS: In 6,192 obese patients (BMI > or =25 kg/m(2)) with mean BMI 36.6 kg/m(2) (SD 6.1) and mean age 40.4 years (SD 12.9) who had been referred to the obesity clinic of the Heinrich-Heine-University Düsseldorf, Germany, between 1961 and 1994, there were 1,058 deaths from all causes during a median follow-up time of 14.8 years. We calculated standardized mortality ratios (SMRs) with 95% confidence intervals (CIs) for death from predefined groups of diseases by using Germany as reference population. RESULTS: In both sexes, risk of death from cardiovascular diseases (men: SMR = 2.2, CI 1.9-2.5; women: SMR = 1.6, CI 1.5-1.8), from diabetes (men: SMR = 5.4, CI 3.2-8.7; women: SMR = 3.5, CI 2.6-4.8), and in men from digestive diseases (SMR = 1.6, CI 1.01-2.3) was significantly increased. In contrast to other studies, an association between obesity and all-cancer mortality could not be found. Only in morbidly obese women (BMI > or =40 kg/m(2)), all-cancer mortality was significantly increased (SMR = 1.5, CI 1.1-1.9). CONCLUSION: Obesity is associated with increased risk of death from cardiovascular diseases and diabetes in both sexes, and from diseases of the digestive system in men.     

Risk of ovarian cancer associated with BMI varies by menopausal status

Obesity has been linked to increased risk of several malignancies, but the role of obesity in the etiology of ovarian cancer remains unclear. Therefore, a hospital-based case-control study was conducted to investigate the association between body size and risk of ovarian cancer. Participants included 427 women with primary, incident ovarian cancer and 854 cancer-free controls. All participants received medical services at Roswell Park Cancer Institute in Buffalo, NY between 1982 and 1998 and completed a comprehensive epidemiological questionnaire. The instrument included questions regarding height and usual wt prior to survey. Participants were classified as underweight/normal (BMI < or = 24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), or obese (BMI > or = 30.0 kg/m2). Compared with underweight/normal participants, being overweight (adjusted odds ratio [OR] = 1.02; 95% CI 0.77-1.36) or obese (adjusted OR = 1.17; 95% CI 0.84-1.65) was not significantly associated with an elevated risk of ovarian cancer. After stratification by menopausal status, BMI showed no significant association to ovarian cancer risk among postmenopausal women (> or = 50 y old). However, among premenopausal women (<50 y old), those classified as obese had a significantly increased risk (adjusted OR = 2.19; 95% CI 1.19-4.04) compared with women classified as normal/underweight. These findings suggest a potential influence of menopausal status on the total endogenous hormonal environment, including estrogens, androgens, and insulin-like growth factors, when considering the association between body size and ovarian cancer risk. In light of the fact that obesity is a modifiable risk factor, further investigation on this topic is warranted.     

The relationship between body mass index and unintended pregnancy: results from the 2002 National Survey of Family Growth

BACKGROUND: The study was conducted to characterize the relationship between body mass index (BMI) and unintended pregnancy, contraceptive use patterns, and perceived fertility. METHODS: This study employed a cross-sectional, nationally representative database (2002 National Survey of Family Growth). Unintended pregnancy was compared among BMI groups [normal (<25 m/kg(2)), overweight (25-30 m/kg(2)) and obese (>30 m/kg(2))]. Analyses also evaluated the association between demographic, socioeconomic, behavioral and health-related variables and BMI. Multiple logistic regression with adjustment for sampling design was used to measure associations of interest. RESULTS: BMI data were available from 6690 nonpregnant women. Of these, 3600 (53.6%) were normal weight, 1643 (25%) were overweight and 1447 (21.4%) were obese. Compared to women with normal BMIs, the risk of unintended pregnancy in the last 5 years did not differ among overweight [adjusted OR 0.95 (95% CI 0.77-1.17)] or obese [adjusted OR 0.87 (95% CI 0.70-1.09)] women. There were no differences in contraceptive use patterns or perceived fertility among BMI groups. CONCLUSION: Data from the 2002 NSFG do not support an association between obesity and unintended pregnancy.     

Diet composition and risk of overweight and obesity in women living in the southwestern United States

OBJECTIVE: It is unknown whether dietary patterns or macronutrient composition contribute to the observed differences in rates of overweight and obesity among Hispanic and non-Hispanic white women in the United States. We assessed the association of dietary patterns and macronutrient composition with overweight and obesity in Hispanic and non-Hispanic white women. DESIGN: Cross-sectional analysis of dietary data from a case-control study of breast cancer. PARTICIPANTS: Population-based control participants (871 Hispanic and 1,599 non-Hispanic white women) from the southwestern United States who completed the diet and other components of the interview and whose anthropometric measurements were available. MAIN OUTCOME MEASURES: Body mass index (BMI; calculated as kg/m(2)), weight status (overweight, BMI 25 to 29.9; obese, BMI>30). STATISTICAL ANALYSES PERFORMED: Dietary patterns were defined using factor analysis. Associations of dietary patterns and macronutrient composition with overweight and obesity as compared with normal weight were assessed with logistic regression. RESULTS: Hispanic women reported consuming more energy, a greater proportion of energy from fat and vegetable protein, less alcohol, and less energy from animal protein compared with non-Hispanic white women. Western and dieter patterns were associated with higher prevalence of overweight and obesity; the Prudent dietary pattern was associated with a 29% lower prevalence of overweight and a halving of the prevalence of obesity similarly in Hispanic and non-Hispanic white women. Higher proportions of energy from protein (odds ratio [OR] 1.81, 95% confidence interval [CI] 1.28 to 2.56) and animal protein (OR 2.10 95% CI 1.47 to 2.98) were associated with a greater risk of overweight; greater proportions of energy from fat (OR 2.28, 95% CI 1.27 to 4.08), protein (3.55 95% CI 2.38 to 5.29), or animal protein (3.44 95% CI 2.31 to 5.14) were associated with higher risk of obesity among non-Hispanic white women only. CONCLUSIONS: A Western dietary pattern was associated with greater risk and a Prudent diet with reduced risk of overweight and obesity. To reduce risk of overweight and obesity, Hispanic women should maintain healthful aspects of a native Hispanic diet, and non-Hispanic white women should replace animal protein with vegetable protein.     

A prospective study of the risk of congenital defects associated with maternal obesity and diabetes mellitus

This study was designed to evaluate the effects of maternal obesity and diabetes mellitus on the risk of nonchromosomal congenital defects. We used data from 22,951 pregnant women enrolled in a prospective cohort study of early prenatal exposures and pregnancy outcome. The relative risks [prevalence ratios (PRs)] of major nonchromosomal congenital defects associated with obesity and diabetes, alone or in combination, were calculated using multiple logistic regression analysis. In this study, in the absence of diabetes, obese women (body mass index > or =28) had no higher risk, overall, of having an offspring with a major defect [PR = 0.95; 95% confidence interval (CI) = 0.62-1.5]. Their offspring, however, did have a higher prevalence of certain types of defects, including orofacial clefts; club foot; cardiac septal defects; and, to a lesser extent, hydrocephaly and abdominal wall defects. Women with pre-existing or gestational diabetes who were not obese also had no excess risk overall of having offspring affected by a major defect (PR = 0.98; 95% CI = 0.43-2.2), although they did have a higher prevalence of musculoskeletal defects. The pregnancies of women who were both obese and diabetic were 3.1 times as likely (95% CI = 1.2-7.6) to result in an offspring with a defect than were those of nonobese, nondiabetic women, which suggests that obesity and diabetes mellitus may act synergistically in the pathogenesis of congenital anomalies. The defects were largely craniofacial or musculoskeletal.     

Sleep duration, general and abdominal obesity, and weight change among the older adult population of Spain

BACKGROUND: Short sleep duration is associated with obesity and weight gain among children and young adults. However, there are few studies on the elderly, with conflicting results. OBJECTIVE: We examined the association of habitual sleep duration with obesity and weight change among the population aged > or =60 y in Spain. DESIGN: This prospective study was conducted from 2001 to 2003 on 3576 persons whose habitual sleep duration was self-reported in 2001. The outcomes were obesity [body mass index (BMI; in kg/m(2)) > or =30], severe obesity (BMI > or =35), and abdominal obesity (waist circumference >102 cm in men and >88 cm in women) in 2001 and weight gain > or =5 kg in the period 2001-2003. RESULTS: Compared with subjects who slept 7 h, subjects who slept < or =5 h had a greater frequency of obesity [odds ratio (OR): 1.33; 95% CI: 1.00, 1.77] and severe obesity (OR: 2.08; 95% CI: 1.31, 3.32). In addition, sleeping 8 h was associated with obesity (OR: 1.39; 95% CI: 1.11, 1.75) and severe obesity (OR: 1.82; 95% CI: 1.21, 2.73). Similarly, subjects sleeping 9 h were more likely to have severe obesity (OR: 1.57; 95% CI: 1.00, 2.47). Among women, weight gain > or =5 kg was more frequent among subjects sleeping < or =5 h (OR: 3.41; 95% CI: 1.34, 8.69), 8 h (OR: 3.03; 95% CI: 1.29, 7.12), and 9 h (OR: 3.77; 95% CI: 1.55, 9.17). No association was observed between sleep duration and abdominal obesity. CONCLUSIONS: Among older adults, sleeping < or =5 h and sleeping 8 or 9 h was associated with obesity and with short-term weight gain in women.     

Age and race impact the association between BMI and CVD mortality in women

OBJECTIVES: In previous studies, we have shown that obesity is associated with increased cardiovascular disease (CVD) mortality in white women but not in black women. Earlier research suggests that body mass index (BMI) has a greater effect on CVD mortality in younger white females than older white females, whereas this relationship in black women is not as clear. This study examines the effect of age on the association of BMI to CVD in black and white women. METHODS: The Black Pooling Project includes data on 2,843 black women with 50,464 person-years of follow-up, and 12,739 white women with 214,606 person-years of follow-up. A Cox proportional hazards model was used to examine the association between BMI and CVD mortality for specific age/race groups. The younger group was < 60 years of age and the older group was > 60 years of age. RESULTS: In younger white women, the relative risk (95% confidence interval [CI]) for CVD mortality was significant in obese women (BMI > 30 kg/m2) vs. women of normal weight (BMI 18.5-24.9 kg/m2) (1.59 [CI 1.20, 2.09]). Similarly, in older white women, the relative risk for CVD mortality in obese women vs. women of normal weight was significant (1.21 [CI 1.04, 1.41]). There were no such associations for black women. Overweight (BMI 25-29.9 kg/m2) was not associated with increased risk in black or white women. CONCLUSION: These findings indicate that obesity is associated with a significantly greater risk of CVD mortality among white women, with the strongest association among white women < 60 years of age.     

Risk of overweight and obesity among semivegetarian, lactovegetarian, and vegan women

BACKGROUND: Observational studies suggest that a plant-based diet is inversely related to body mass index (BMI), overweight, and obesity. OBJECTIVE: Our objective was to examine the BMI (kg/m(2)) and risk of overweight and obesity of self-defined semivegetarian, lactovegetarian, and vegan women. DESIGN: Data analyzed in this cross-sectional study were from 55459 healthy women participating in the Swedish Mammography Cohort. Women were asked whether they considered themselves to be omnivores (n = 54257), semivegetarians (n = 960), lactovegetarians (n = 159), or vegans (n = 83), and this question was the main exposure variable in this study. In secondary analyses, we reclassified women as lactovegetarians on the basis of food intakes reported on the food-frequency questionnaire. RESULTS: The prevalence of overweight or obesity (BMI >/= 25) was 40% among omnivores, 29% among both semivegetarians and vegans, and 25% among lactovegetarians. In multivariate, adjusted logistic regression analyses, self-identified vegans had a significantly lower risk of overweight or obesity [odds ratio (OR) = 0.35; 95% CI: 0.18, 0.69] than did omnivores, as did lactovegetarians (OR = 0.54; 95% CI: 0.35, 0.85) and semivegetarians (OR = 0.52; 95% CI: 0.43, 0.62). Risk of overweight or obesity remained significantly lower among lactovegetarians classified on the basis of the food-frequency questionnaire (OR = 0.48; 95% CI: 0.30, 0.78). CONCLUSIONS: Even if vegetarians consume some animal products, our results suggest that self-identified semivegetarian, lactovegetarian, and vegan women have a lower risk of overweight and obesity than do omnivorous women. The advice to consume more plant foods and less animal products may help individuals control their weight.     

Body mass index and risk for oral contraceptive failure: a case-cohort study in South Carolina

PURPOSE: Studies have suggested that obesity is associated with an increased risk for oral contraceptive (OC) failure. We conducted a case-cohort study in South Carolina to examine the association between body mass index (BMI) and OC failure by using population-based data sources. METHODS: Our cohort sample from the source population consists of 205 women who reported using OCs to prevent pregnancy on the 1999 Behavioral Risk Factor Surveillance System survey. The 153 women who reported using OCs at the time of conception on the 2000 Pregnancy Risk Assessment Monitoring System survey represent the case sample that arose from the source population. Logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: In unadjusted models with normal BMI (20 to 24.9 kg/m(2)) as the comparison, greater BMI was associated significantly with OC failure (overweight [25 to 29.9 kg/m(2)], OR = 2.54; 95% CI, 1.18-5.50; and obese [> or =30 kg/m(2)], OR = 2.82; 95% CI, 1.05-7.58). After adjustment for education, income, and race/ethnicity, associations were attenuated and no longer statistically significant. CONCLUSIONS: In this heterogeneous population, we found a suggestion that overweight and obese women may be at increased risk for OC failure. However, long-term prospective studies are needed to study this association in diverse populations.     

Lowered weight gain during pregnancy and risk of neural tube defects among offspring

BACKGROUND: Maternal nutritional factors have been implicated in the complex aetiology of neural tube defects (NTD). We investigated whether the amount of weight a woman gained during pregnancy was associated with her risk of delivering an infant with an NTD. METHODS: We conducted a population-based case-control study within the cohort of 708 129 live births and fetal deaths occurring in selected California counties in 1989-1991. Face-to-face interviews were conducted with mothers of 538 (88% of eligible) NTD cases (including those electively terminated, stillborn, or liveborn) and with mothers of 539 (88%) non-malformed liveborn controls within an average of 5 months from the term delivery date. Respondent-reported weight gain during pregnancy (kg) was analysed. Risks of infants having NTD were estimated among women who gained <10 kg compared to those who gained > or =10 kg during > or =38 week gestations. RESULTS: Compared to women who gained > or =10 kg, an increased risk for NTD offspring was observed among women who gained <10 kg (odds ratio [OR] = 3.2, 95% CI : 2.3-4.6). The OR was 5.0 (95% CI : 2.6-9.7) among those women who gained <5 kg during pregnancy. The increased risk was not attributable to maternal non-use of a multivitamin containing folic acid, diabetes, NTD-pregnancy history, age, race/ethnicity, education, gravidity, alcohol use, cigarette use, prepregnant obesity, low socioeconomic status, dieting, nausea, nor to lower dietary intakes of folate, zinc, energy, protein, fat, carbohydrates, and methionine. An increased risk was observed even after simultaneous adjustment for most of these factors (OR = 2.2, 95% CI : 1.2-3.8). The risk associated with gaining <10 kg was greater for anencephaly, but still elevated for spina bifida. CONCLUSIONS: We did not have information on weight gain during early pregnancy. Because weight gain during the relevant embryological period for NTD (first month post-conception) is relatively small and often variable, it seems less likely that elevated NTD risks indicate a causal association between lowered weight gain throughout pregnancy and abnormal development of the neural tube. It seems more likely that lowered weight gain is a consequence of carrying an NTD-affected fetus. However, what this consequence is and why risk was substantially larger for anencephaly is unknown.     

Trends in body mass index and prevalence of obesity in Swedish women 1980-89.

STUDY OBJECTIVE--To assess changes in the body mass index (BMI, weight (kg)/height2 (m2)) and in the prevalence of obesity in Swedish women during the 1980s. DESIGN--Data from two successive cross sectional surveys were used. SETTING--The whole of Sweden. SUBJECTS--A total of 7419 women from a 1980-81 survey (response rate 84.6%) and 6306 women from a 1988-89 survey (response rate 80.3%), aged 16-84 years, and forming a representative sample of Swedish women. MEASUREMENTS AND MAIN RESULTS--The results were based on self reported weight and height during interview. The mean BMI of the whole population, adjusted for age, education level, socioeconomic group, region, and nationality, increased by 0.17 kg/m2 (p = 0.0056) over the eight year period. The increase was particularly pronounced in the group aged 25-34 years (0.74 kg/m2; p < 0.0001, which corresponds to more than 2 kg for a woman 168 cm tall). The higher mean BMI was also reflected in the relative increase in the prevalence of obesity (BMI > 28.6 kg/m2) by 19% (odds ratio (OR) = 1.19; 95% confidence interval (CI): 1.04, 1.37) and of the combination of overweight and obesity (BMI > 23.8 kg/m2) by 12% (OR = 1.12; 95% CI 1.03, 1.23) in the whole female population. CONCLUSIONS--During the 1980s the mean BMI and the prevalence of overweight and obesity in adult Swedish women increased. An influence of the sociocultural environment on the body weight in women was stronger than that in men.     

Maternal and gestational risk factors for hypospadias

BACKGROUND: An increase in the prevalence of hypospadias has been reported, but the environmental causes remain virtually unknown. OBJECTIVES: Our goal was to assess the association between risk of hypospadias and indicators of placental function and endogenous hormone levels, exposure to exogenous hormones, maternal diet during pregnancy, and other environmental factors. METHODS: We conducted a case-control study in Sweden and Denmark from 2000 through 2005 using self-administered questionnaires completed by mothers of hypospadias cases and matched controls. The response rate was 88% and 81% among mothers of cases and controls, respectively. The analyses included 292 cases and 427 controls. RESULTS: A diet during pregnancy lacking both fish and meat was associated with a more than 4-fold increased risk of hypospadias [odds ratio (OR) = 4.6; 95% confidence interval (CI), 1.6-13.3]. Boys born to obese [body mass index (BMI) > or = 30] women had a more than 2-fold increased risk of hypospadias (OR = 2.6; 95% CI, 1.2-5.7) compared with boys born to mothers with a normal weight (BMI = 20-24). Maternal hypertension during pregnancy and absence of maternal nausea increased a boy's risk of hypospadias 2.0-fold (95% CI, 1.1-3.7) and 1.8-fold (95% CI, 1.2-2.8), respectively. Nausea in late pregnancy also appeared to be positively associated with hypospadias risk (OR = 7.6; 95% CI, 1.1-53). CONCLUSIONS: A pregnancy diet lacking meat and fish appears to increase the risk of hypospadias in the offspring. Other risk associations were compatible with a role for placental insufficiency in the etiology of hypospadias.     

Obesity and associated coronary heart disease risk factors in a population of low-income African-American and white women: the North Carolina WISEWOMAN project

BACKGROUND: Obesity has been associated with many co-occurring coronary heart disease (CHD) risk factors as well as CHD mortality. These associations have been shown to vary between African-American and white sample populations. METHODS: The authors examined whether obesity co-occurs with several CHD risk factors (diabetes, hypertension, hypercholesterolemia, low high-density lipoprotein cholesterol (HDL-C)), and estimated the 10-year risk for CHD in the North Carolina WISEWOMAN (Well Integrated Screening and Evaluation for Women Across the Nation) study sample. This sample includes low-income African-American and white women (> or = 50 years of age). RESULTS: Among white women (n = 1,284), 34% were overweight (BMI = 25.0-29.99 kg/m(2)) and 35% obese (BMI > or = 30 kg/m(2)); among African-American women (n = 754), 28% were overweight and 59% obese. Among obese and nonobese African-American women, the prevalence of three or more co-occurring risk factors was similar (obese = 17.7% (95% confidence interval (CI): 13.9, 21.6) and nonobese = 13.3% (95% CI: 8.7, 17.8)). By contrast, the prevalence among white women was greater among the obese (26.9% (95% CI: 22.9, 31.0)) than the nonobese (13.0% (95% CI: 9.7, 16.2)). CONCLUSIONS: The differences between and within African-American and white women may be accounted for by the high levels of HDL-C among obese and nonobese African-American women.     

From infancy to pregnancy: birth weight, body mass index, and the risk of gestational diabetes

Obesity is a risk factor for gestational diabetes, whereas the role of the mother’s birth weight is more uncertain. We aimed to investigate the combined effect of mothers’ birth-weight-for-gestational-age and early pregnancy Body Mass Index (BMI) in relation to risk of gestational diabetes. Between 1973 and 2006, we identified a cohort of 323,083 women included in the Swedish Medical Birth Register both as infants and as mothers. Main exposures were mothers’ birth-weight-for-gestational-age (categorized into five groups according to deviation from national mean birth weight) and early pregnancy BMI (classified according to WHO). Rates of gestational diabetes increased with adult BMI, independently of birth-weight-for-gestational-age. However, compared to women with appropriate birth-weight-for-gestational-age [appropriate-for-gestational age (AGA); ?1 to +1 SD] and BMI (<25.0), women with obesity class II-III (BMI?≥?35.0) had an adjusted odds ratio (OR) of 28.7 (95?% confidence interval, CI 17.0–48.6) for gestational diabetes if they were born small-for-gestational-age [small for gestational age (SGA); <?2SD], OR?=?20.3 (95?% CI 11.8–34.7) if born large-for-gestational-age [large-for-gestational-age (LGA); >2SD], and OR?=?10.4 (95?% CI 8.4–13.0) if born AGA. Risk of gestational diabetes is not only increased among obese women, but also among women born SGA and LGA. Severely obese women born with a low or a high birth-weight-for-gestational-age seem more vulnerable to the development of gestational diabetes compared to normal weight women. Normal pre-pregnancy BMI diminishes the increased risk birth size may confer in terms of gestational diabetes. Therefore, the importance of keeping a healthy weight cannot be overemphasized.