Diet quality and its association with type 2 diabetes and major cardiometabolic risk factors among adults in China.

AIM: We examined the association between diet quality and diabetes and major cardiometabolic risks among adults in China. METHODS AND RESULTS: We developed the China Dietary Guideline Index (CDGI) based on the 2007 Chinese dietary guidelines and tailored the Alternate Healthy Eating Index 2010 (which we call the tAHEI) to assess diet quality. Our analysis linked the dietary intake and covariates measured in 2006 with CM risk factors measured in 2009. We used diet data the longitudinal China Health and Nutrition Survey 2006 collected in 3 consecutive 24-h recalls from 4440 adults aged 18 to 65 to calculate both the tAHEI and the CDGI scores. We performed multivariable logistic regressions to analyze the association of each 2006 score with diabetes, abdominal obesity, elevated blood pressure, and lipid-related cardiometabolic risk factors in 2009. After we adjusted for potential confounders, adults in the top quintile compared with the bottom quintile of the tAHEI scores showed 36% lower odds of high low-density lipoprotein cholesterol (LDL-C) (odds ratio [OR] 0.64; 95% confidence interval [CI] 0.46, 0.90] in men and 33% lower odds (OR 0.67; 95% CI 0.49, 0.91) in women, while the CDGI scores showed 35% lower odds of high LDL-C (OR 0.65; 95% CI 0.46, 0.92) in men only. Further, the CDGI scores indicated 55% lower odds of diabetes in the top versus the bottom quintile (OR 0.45; 95% CI 0.23, 0.87) in men only, whereas a null association was observed for the tAHEI scores for both sexes. Both index scores showed null associations with other cardiometabolic risk factors. CONCLUSIONS: Chinese diets that scored high on both the CDGI and the tAHEI showed similarly negative associations with high LDL-C risk, whereas only CDGI score was negatively related to diabetes risk in men.

How could complementary feeding patterns affect the susceptibility to NCD later in life?

AIMS: The purpose of this paper is to provide a general framework for thinking about pathways and potential mechanisms through which complementary feeding may influence the risk of developing non-communicable diseases (NCDs). DATA SYNTHESIS: To provide a context for the lack of clear and consistent evidence relating complementary feeding to NCD risk, methodological challenges faced in trying to develop an evidence base are described. Potential pathways through which complementary feeding may influence obesity-related NCD risk are described and illustrated with examples. CONCLUSIONS: Numerous aspects of complementary feeding, including diet composition as well as patterns of feeding have the potential to influence the early development of obesity, which in turn predicts later obesity and NCD risk. Specific dietary exposures during the period of complementary feeding also have the potential to program future disease risk through pathways that are independent of adiposity. These factors all require consideration when making recommendations for optimal complementary feeding practices aimed at prevention of future NCDs.

Does lower birth order amplify the association between high socioeconomic status and central adiposity in young adult Filipino males?

OBJECTIVES: To test the hypothesis that lower birth order amplifies the positive association between socioeconomic status and central adiposity in young adult males from a lower income, developing country context. DESIGN: The Cebu Longitudinal Health and Nutrition Survey is an ongoing community-based, observational study of a 1-year birth cohort (1983). SUBJECTS: 970 young adult males, mean age 21.5 years (2005). MEASUREMENTS: Central adiposity measured by waist circumference; birth order; perinatal maternal characteristics including height, arm fat area, age and smoking behavior; socioeconomic status at birth and in young adulthood. RESULTS: Lower birth order was associated with higher waist circumference and increased odds of high waist circumference, even after adjustment for socioeconomic status in young adulthood and maternal characteristics that could impact later offspring adiposity. Furthermore, the positive association between socioeconomic status and central adiposity was amplified in individuals characterized by lower birth order. CONCLUSIONS: This research has failed to reject the mismatch hypothesis, which posits that maternal constraint of fetal growth acts to program developing physiology in a manner that increases susceptibility to the obesogenic effects of modern environments.

Differential influences of early growth and social factors on young children's cognitive performance in four low-and-middle-income birth cohorts (Brazil, Guatemala, Philippines, and South Africa).

BACKGROUND: Studies relating childhood cognitive development to poor linear growth seldom take adequate account of social conditions related to both, leading to a focus on nutrition interventions. We aimed to assess the roles of both biological and social conditions in determining early childhood cognition, mediated by birthweight and early linear growth. METHODS: After exploratory structural equation modelling to identify determining factors, we tested direct and indirect paths to cognitive performance through birthweight and child height-for-age at 2 years, assessed between 4 and 8.5 years of age among 2448 children in four birth cohort studies in low-and-middle-income countries (Brazil, Guatemala, Philippines and South Africa). Determinants were compared across the cohorts. FINDINGS: Three factors yielded excellent fit, comprising birth endowment (primarily maternal age and birth order), household resources (crowding, dependency) and parental capacity (parental education). We estimated their strength together with maternal height in determining cognitive performance. Percentage shares of total effects of the four determinants show a marked transition from mainly biological determinants of birth weight (birth endowment 34%) and maternal height (30%) compared to household resources (25%) and parental capacity (11%), through largely economic determinants of height at 2 years (household resources (60%) to cognitive performance being predominantly determined by parental capacity (64%) followed by household resources (29%). The largely biological factor, birth endowment (maternal age and birth order) contributed only 7% to childhood cognitive performance and maternal height was insignificant. In summary, the combined share of social total effects (household resources and parental capacity) rises from 36∙2% on birth weight, to 78∙2% on height for age at 24 m, and 93∙4% on cognitive functioning. INTERPRETATION: Across four low- and middle-income contexts, cognition in childhood is influenced more by the parental capacity of families and their economic resources than by birth weight and early linear growth. Improving children's cognitive functioning requires multi-sectoral interventions to improve parental education and enhance their economic wellbeing, interventions that are known to improve also early childhood growth.

Longitudinal relationships between occupational and domestic physical activity patterns and body weight in China.

OBJECTIVES: To examine the longitudinal relationship between occupational and domestic sources of physical activity and body weight in a sample of Chinese adults. METHODS: Population-based longitudinal observational study of Chinese adults (4697 women and 4708 men) aged 18-55 from the 1991, 1993, 1997, and 2000 waves of the China Health and Nutrition Survey. Measured height and weight and detailed self-reported energy expenditure from multiple occupational and domestic sources were assessed over a 9-year period. Longitudinal relationships were modeled using linear random effects models. RESULTS: Increased occupational physical activity resulted in overall lower body weight for both men and women (beta-coefficients (95% confidence interval (CI)) for high levels: -0.46 (-0.76, -0.15) for men, -0.36 (-0.62, -0.10) for women, and increased domestic physical activity resulted in overall lower body weight in men (beta-coefficient (95% CI): -0.40 (-0.62, -0.18)). CONCLUSIONS: Physical activity that occurs in the occupational and domestic sectors is often overlooked; yet our research suggests they have important effects on body weight in Chinese adults. As China continues to urbanize, energy expenditure from these sources is decreasing, and our results point out the need to explore these types of physical activity more broadly across the world as potential sources of weight gain.

Concordance of haemoglobin A1c, blood pressure and C-reactive protein between children and their parents in Chinese households.

BACKGROUND: China has the world's highest diabetes prevalence, which along with hypertension and inflammation continues to grow particularly among children. Little is known about the strength of the association of these cardiometabolic risk factors between parents and their children; thus, the potential of household-based strategies to reduce risk is unknown. OBJECTIVES: The objective of the study is to examine the parent-child association for haemoglobin A1c (HbA1c), blood pressure (BP) and C-reactive protein (CRP) in a large, geographically diverse Chinese sample. METHODS: In 940 parent-child pairs (children aged 7-17 years) who participated in the 2009 China Health and Nutrition Survey, we measured each individual's HbA1c and CRP using fasting blood and BP. We used sex-specific random-effects linear regression to examine the parent-child association for these risk factors, accounting for within-family clustering. RESULTS: Child's HbA1c was positively associated with parental HbA1c. Beta coefficients ranged from 0.06 (95% CI 0.03-0.12) for father-daughter to 0.43 (95% CI 0.28-0.58) for mother-son pairs. We also detected a positive mother-daughter association for BP and positive father-child associations for CRP. CONCLUSION: The statistically significant parent-child association for HbA1c, BP and CRP in Chinese families suggests that household-based interventions could be useful for confronting the high rates of diabetes, hypertension and inflammation in China.

Sociodemographic disparity in the diet quality transition among Chinese adults from 1991 to 2011.

BACKGROUND/OBJECTIVES: This study investigates secular trends in diet quality distribution and related socioeconomic disparity from 1991 to 2011 in the Chinese adult population. SUBJECTS/METHODS: The analysis uses the 1991-2011 China Health and Nutrition Survey data on 13 853 participants (6876 men and 6977 women) aged 18-65 with 56 319 responses. Dietary assessment was carried out over a 3-day period with 24-h recalls combined with a household food inventory. We tailored Alternative Healthy Eating Index 2010 (named as tAHEI) to measure diet quality and performed quantile regression to investigate shifts in tAHEI scores at different percentiles and used mixed-effect linear regression to examine average diet quality trend and potential sociodemographic disparity. RESULTS: The energy-adjusted mean tAHEI scores increased from 36.9 (36.7-37.1) points in 1991 to 50.3 (50.1-50.5) in 2011 for men (P<0.001) and from 35.6 (35.4-35.8) to 46.9 (46.7-47.1) for women (P<0.001). The covariate-adjusted score of polyunsaturated fatty acids increased by 6.8 (6.6, 7.0) and 7.0 (6.9, 7.2), and the score of long-chain (ω-3) fats increased by 5.3 (5.2, 5.4) and 5.3 (5.2, 5.5) in men and women, respectively, whereas the cereal fiber and red meat scores decreased slightly. Increasing tAHEI score occurred across the entire distribution, and diet quality transition varied across sociodemographic groups. CONCLUSIONS: Chinese diet quality is far from optimal, with moderate improvement over a 21-year period. Findings suggest that nutritional intervention should give priority to low-income, low-urbanized communities and southern provincial adults with low diet quality in China.

Sex differences in obesity incidence: 20-year prospective cohort in South Africa.

BACKGROUND: Prospective data spanning childhood and adolescence are needed to better understand obesity incidence among children and to identify important periods for intervention. OBJECTIVE: To describe gender differences in overweight and obesity from infancy to late adolescence in a South African cohort. METHODS: We analysed body mass index at 1-2 years, 4-8 years, 11-12 years, 13-15 years and 16-18 years among 1172 participants in the South African Birth-to-Twenty cohort. RESULTS: Among boys, overweight and obesity prevalence declined from age 1-2 years to 16-18 years. Among girls, overweight and obesity prevalence increased from 4-8 years to 16-18 years. Obesity incidence was highest from 4-8 years to 11-12 years in boys (6.8 cases per 1000 person-years) and from 11-12 years to 13-15 years in girls (11.2 cases per 1000 person-years). Among girls, obesity at 16-18 years was associated with overweight (odds ratio [OR] = 3.6; 95% confidence interval [CI] 1.8-7.2) or obesity (OR = 8.0; 95% CI 3.7-17.6) at 1-2 years and overweight (OR = 6.8; 95% CI 3.3-13.9) or obesity (OR = 42.3; 95% CI 15.0-118.8) at 4-8 years; for boys, obesity at 16-18 years was associated with overweight at 1-2 years (OR = 5.6; 95% CI 1.7-18.0) and obesity at 4-8 years (OR = 19.7; 95% CI 5.1-75.9). CONCLUSIONS: Among girls, overweight and obesity increased throughout childhood. Overweight and obesity were not widely prevalent among boys. Early childhood and post-puberty may be important periods for intervention among girls.

Maternal energy stores and diet composition during pregnancy program adolescent blood pressure.

BACKGROUND: Fetal undernutrition is hypothesized to program blood pressure (BP) later in life. Human epidemiological studies that use birth weight as a proxy for fetal malnutrition fail to identify specific aspects of maternal nutrition responsible for programming. METHODS AND RESULTS: We examined how maternal nutrition during pregnancy and infant birth weight relate to systolic and diastolic BP (SBP and DBP) in 2026 Filipino adolescents. Data were collected prospectively during the Cebu (Philippines) Longitudinal Health and Nutrition Survey. Women were assessed at approximately 30 weeks gestation, and children were followed from birth through adolescence. Regression models were used to examine how the mothers' total energy intake, percentage of energy from protein and fat, triceps skinfold thickness during pregnancy, and infant birth weight relate to adolescent BP, controlling for current age, height, and body mass index and other potential confounders. Maternal triceps skinfold thickness was significantly inversely related to SBP among boys and to DBP in boys and girls. Maternal nutrition variables attenuated but did not eliminate an inverse birth weight-SBP relationship in boys. SBP was significantly inversely related to the mothers' percent of dietary energy from protein in boys. Among girls, SBP and DBP were inversely related to the mothers' percentage of calories from fat. There was no evidence of confounding of these relationships by current diet, maturation status, physical activity, or socioeconomic status. CONCLUSIONS: Maternal diet composition and energy stores in the form of subcutaneous fat have long-term effects on offspring BP in adolescence.

Do protein and energy intakes explain long-term changes in body composition?

BACKGROUND: Despite evidence that profiles of protein and energy intake can determine short-term (< 1 y) change in both lean and fat compartments,the role of diet in longer-term, age-related changes in body composition remains unclear. OBJECTIVE: This paper tests for long-term counterparts to the well-established short-term relationships between protein and energy intake and changes in body composition. DESIGN: Using longitudinal data on 608 healthy, non-obese Chinese (50-69 y)from the 1993 and 1997 China Health and Nutrition Surveys, sex-specific regression models were created to determine if 3-day mean protein (%of energy) and energy (kJ) intakes at baseline predicted change in mid arm muscle area (MAMA) and waist circumference (WC). RESULTS: Although sex-specific U-shaped associations were observed,higher energy intakes were associated with greater gain in WC and less loss of MAMA, and higher protein intakes with less loss of MAMA than lower intakes for both sexes, adjusting for baseline age, height, weight, MAMA, WC, smoking status, activity level, income and urban residence. For males, energy intake be low 95%of the Chinese RDA was associated with significantly smaller gains in WC and greater loss of MAMA than energy intake between 95-125% RDA. For both sexes, protein intake be low 10.4% of energy was associated with significantly greater loss of MAMA than intake between 10.4-12.1% of energy. For females, energy intake above 125% RDA was associated with significantly greater gains in body fat than intake between 95-125% RDA. CONCLUSION: The results suggest that diet may play an important role in age-related change in body composition.

Slow early growers have more muscle in relation to adult activity: evidence from Cebu, Philippines.

BACKGROUND/OBJECTIVES: Adult skeletal muscle mass (SMM) protects against type 2 diabetes, but little is known about its developmental antecedents. We examined whether pace of early weight gain predicted adult SMM in a birth cohort from Cebu City, Philippines. In addition, we examined whether increases in SMM associated with adult muscle-building exercise varied according to the early growth. SUBJECTS/METHODS: Data came from 1472 participants of the Cebu Longitudinal Health and Nutrition Survey. Weight was measured at birth and at 6-month intervals through the age of 24 months. Adult SMM was estimated from anthropometric measurements when participants were 20-22-years old. Interviews provided the information on adult exercise/lifestyle habits. RESULTS: SMM (mean ± s.d.) was 20.8 ± 3.9 kg (men) and 13.6 ± 3.4 kg (women). Faster early weight gain predicted a higher adult SMM. After adjustment for height and lifestyle factors, strongest associations with SMM were found for 6-12 months growth in men (ß=0.17, P=0.001) and for birth weight in women (ß=0.14, P=0.001). Individuals who had grown slowly displayed greater SMM in association with adult weightlifting, basketball playing and physically demanding forms of employment (men) or household chores (women). CONCLUSIONS: These results suggest heightened sensitivity of activity-induced muscle hypertrophy among the adults who were born light or who gained weight slowly as infants. Future research should test this finding by comparing responses of muscle mass to an intervention in slow vs fast early growers. Findings suggest that adults who display a reduced SMM following suboptimal early growth may be good candidates for new anti-diabetes interventions that promote muscle-building activities.

Implications of iron deficiency/anemia on the classification of diabetes using HbA1c.

BACKGROUND/OBJECTIVES: Nonglycemic factors like iron deficiency (ID) or anemia may interfere with classification of diabetes and prediabetes using hemoglobin A1c (HbA1c). However, few population-based studies of diabetes in areas with endemic ID/anemia have been conducted. We aimed to determine how mutually exclusive categories of ID alone, anemia alone and iron-deficiency anemia (IDA) were each associated with prediabetes and diabetes prevalence using fasting blood glucose (FBG) versus HbA1c in a population-based study of adults with endemic ID/anemia. SUBJECTS/METHODS: We used data from the China Health and Nutrition Survey, a longitudinal, population-based study across 228 communities within nine provinces of China. This analysis included 7308 adults seen in the 2009 survey aged 18-75 years. We used descriptive and covariate-adjusted models to examine relative risk of prediabetes and diabetes using FBG alone, HbA1c alone, HbA1c and FBG, or neither (normoglycemia) by anemia alone, ID alone, IDA or normal iron/hemoglobin. RESULTS: Approximately 65% of individuals with diabetes in our sample were concordantly classified with diabetes using both FBG and HbA1c, while 35% had a discordant diabetes classification: they were classified using either FBG or HbA1c, but not both. Fewer participants with ID alone versus normal iron/hemoglobin were classified with diabetes using HbA1c only. From covariate-adjusted, multinomial regression analyses, the adjusted prevalence of prediabetes using HbA1c only was 22% for men with anemia alone, but 13% for men with normal iron/hemoglobin. In contrast, the predicted prevalence of prediabetes using HbA1c only was 8% for women with ID alone, compared with 13% for women with normal iron/hemoglobin. CONCLUSIONS: These findings suggest potential misclassification of diabetes using HbA1c in areas of endemic ID/anemia. Estimating diabetes prevalence using HbA1c may result in under-diagnosis in women with ID and over-diagnosis in men with anemia.

Outcome of maternal nutritional supplementation: a comprehensive review of the Bacon Chow study.

In a double blind controlled intervention, two groups of nutritionally at-risk rural Taiwanese women were given a nutrient-rich dietary supplement (group A, n = 114) or a placebo (group B, n = 111) beginning after the birth of one child and continuing through the lactation period for a subsequent child. Outcome variables assessed include infant birth measurements postnatal physical growth, motor, mental, and dental development, morbidity, and maternal weight and skinfold changes during pregnancy and lactation. While few A-B differences in mean values of outcome variables were found, there were significant responses in subgroups of the sample. Comparisons of infants born after a nutrient-supplemented pregnancy (A2) versus an unsupplemented pregnancy (A1) showed that A2 male infants weighed more than A1 males at birth, and A1-A2 sibling correlations in birth measurements, especially Rohrer's index (wt/l3) were significantly reduced. Important mediators of supplement effects included sex of the offspring, season of birth, maternal body size, and birth of a previous infant characterized by dysmorphic prenatal growth. The limited effects of supplementation on the population as a whole may reflect the operation of long term adaptations which allow women to maintain reproductive success despite their apparent marginal nutritional status.

PIP: In the 1960's researchers followed 294 women between 19-30 years old from the last trimester of 1 pregnancy and subsequent lactation through a 2nd pregnancy and lactation in rural Taiwan to determine if maternal undernutrition adversely affects the growth and development of their children. They randomly assigned each mother either a chocolate flavored rich liquid supplement (group A) or a placebo that looked and tasted the same but with limited nutrient value (group B) 3 weeks after the 1st birth. No significant differences in mean birth weight, length, or head circumference existed either in males or females between groups A and B. A significant difference did exist, however, in mean birth weight between the 1st and 2nd group A males (p.05). The maternal nutrition supplement contributed to a mean weight gain of 162g for males. Therefore sex of the offspring mediated the effects of the maternal supplement. Further Rohrer's index of body proportion (weight/length cubed) indicated more sensitively the positive supplement effects in group A siblings. This was especially true when the older siblings had a dysmorphic growth pattern. Before receiving nutrient supplements and during the hot, humid summer months, mothers in both groups weighed less and their children weighed significantly less than the rest of the year. These differences no longer occurred during the 2nd pregnancy and lactation. Other significant mediators of supplement effects were maternal body size and an earlier infant of dysmorphic prenatal growth. In conclusion, nutritional supplementation did not bring about distinct differences between the absolute anthropometric values of groups A and B. Over many years women must have adapted to low nutrition intake by maintaining the ability to reproduce.

Biological determinants of pregnancy weight gain in a Filipino population.

Patterns of pregnancy weight gain and predictors of first trimester and total weight gain were investigated in a sample of 1367 women from Cebu, Philippines, with pregnancy intervals of < 2 y. The mean total weight gain based on actual measurements of prepregnant weight was 8.4 kg. Controlling for gestational week when weight was measured, multivariate-regression models predicted higher first trimester weight gain with higher parity, lower prepregnant body mass index (BMI), and longer nonpregnant intervals. Higher total weight gain was associated with longer nonpregnant intervals, lower prepregnant BMI, taller maternal stature, and relatively high dietary energy intakes. Lactation into the third trimester of pregnancy and maternal age over 35 y had significant negative effects on total weight gain. Given the importance of maternal weight gain in predicting birth outcome, this study provides information on modifiable risk factors that should be considered when developing maternal-infant health policy and programs.

PIP: A study of 1983-87 longitudinal data examined patterns of pregnancy weight gain and predictors of pregnancy weight gain among 1367 pregnant women from Cebu, the Philippines. Mean total weight gain was 8.4 kg. The women began gaining weight more slowly than did women in developed countries then caught up until 22-24 weeks gestation at which time their weight gain rate was considerably lower. Underweight women always gained more weight than normal and overweight women (e.g., during the 1st trimester, .07 kg/week vs. -.8 kg/week; p .05). During the 3rd trimester, women with an overlap of pregnancy and lactation gained much more weight than women with no overlap (.31 kg/week vs. .22 kg/week; p .05). The multivariate regression confirmed that women with a low prepregnant body mass index (BMI) gained more weight than did women with a normal or high BMI (p .01). Higher total weight gain during the 1st trimester was also linked to longer nonpregnant intervals (p .01). This was also true for total weight gain (p .01). A woman with a 6-month pregnancy interval gained 1.27 kg less during the entire pregnancy than a women with an 18-month pregnancy interval. Taller women gained more weight than did shorter women (p .01). Women who had high caloric intake gained more weight than did women who had low caloric intake (p .05). Women older than 35 gained less weight than younger women (p .01). Women who breast fed into the 3rd trimester of pregnancy gained 1.84 kg less than a woman who breast fed only into the 1st trimester (p .01). Women with any overlap of pregnancy and lactation gained more weight during the 3rd trimester than did women with no overlap, suggesting a rebound effect. Thus, public health programs should promote birth spacing and sound nutritional status and encourage breast-feeding pregnant mothers to consume more energy and nutrients to meet the demands of pregnancy and breast feeding.

Prenatal undernutrition, postnatal environments, and antibody response to vaccination in adolescence.

BACKGROUND: Recently, researchers have considered the fetal and infant origins of several adult cardiovascular and metabolic diseases, but the implications of early events for immune function and infectious disease are unclear. OBJECTIVE: We investigated the association between prenatal undernutrition and immunocompetence in adolescence and hypothesized that intrauterine growth retardation is associated with a lower likelihood of mounting an adequate antibody response later in life. DESIGN: A subsample of one hundred three 14-15-y-olds was recruited from an ongoing longitudinal study in which data collection began while participants were in utero. A typhoid vaccine was given, and anti-typhoid antibodies were measured 2 wk and 3 mo later as a functional marker of immunocompetence. The likelihood of mounting an adequate antibody response was compared for adolescents who were small for gestational age or appropriate for gestational age at birth while controlling for a range of postnatal exposures. RESULTS: The predicted probability of mounting a positive antibody response for adolescents who were prenatally and currently undernourished was 0.32, compared with probabilities of 0.49-0.70 for adequately nourished adolescents (P = 0.023). Diarrhea in the first year of life (P = 0.009) and fast weight gain during the first 6 mo (P = 0.003) were also associated with a higher probability of response. CONCLUSIONS: These findings extend the concept of fetal and early infant programming of adult diseases to the immune system and suggest that early environments may have long-term implications for immunocompetence and infectious disease risk, particularly in developing countries.

Low birth weight and intrauterine growth retardation in Filipino infants.

Low birth weight, prematurity, and intrauterine growth retardation represent important health tasks for neonates. Pregnancy outcome risk categories based on combinations of these variables and a measure of body proportions were developed and tested with respect to how well they predict poor growth during infancy. Data were collected during a prospective community-based survey of births representative of the Cebu region of the Philippines. In the sample of 2139 births for which there were available birth weight and gestational age data, 20% of infants were classified as growth retarded and 12% were low birth weight. Low birth weight, the more conservative category, was a better predictor of small infant size at 12 months of age than intrauterine growth retardation. Rohrer's index, which captures information about patterns of intrauterine growth, improves the positive predictive value of categories based either on intrauterine growth retardation or low birth weight. Infants who had an adequate Rohrer's index, ie, were well proportioned at birth, were smaller at 12 months of age than infants who had a low Rohrer's index, ie, had weight deficits relative to their lengths at birth. Important questions about the value of the intrauterine growth retardation classification are raised by the results.

Women's physical activity and pregnancy outcome: a longitudinal analysis from the Philippines.

We assessed the effects of physical activity on pregnancy outcome in 2741 Filipino women identified during pregnancy as part of a two-year longitudinal study. Specific elements of physical activity hypothesized to be relevant to pregnancy outcome were posture, energy expenditure, and physical stress. Variables were developed for nine household and 48 formal and informal economic activities. Analyses were stratified by whether the woman performed formal waged work outside of the home, income-related activity at home, or was economically inactive. Results show that traditional definitions of physical activity and work based on participation in the formal labour force ignore a sizeable amount of home economic production, as well as the physical demands of housework. We saw no difference in risk of low birthweight or preterm delivery in economically active compared to economically inactive women. However, we found that increased amounts of standing activity affected pregnancy outcome in certain groups of women. Accurate assessment of the effects of physical activity during pregnancy must examine specific components of the activity, rather than relying on formal employment as a proxy for exposure.

PIP: The authors assessed the effects of physical activity on pregnancy outcome in 2741 Filipino women identified during pregnancy as part of a 2-year longitudinal study. Specific elements of physical activity hypothesized to be relevant to pregnancy outcome were posture, energy expenditure, and physical stress. Variables were developed for 9 household and 48 formal and informal economic activities. Analyses were stratified by whether the women performed formal waged work outside the home, income-related activity at home, or were economically inactive. Results show that traditional definitions of physical activity and work based on participation in the formal labor force ignore a sizeable amount of home economic production, as well as the physical demands of housework. The authors saw no difference in risk of low birthweight or preterm delivery in economically active compared to economically inactive women. However, they did find that increased amounts of standing activity affected pregnancy outcome in certain groups of women. Accurate assessment of the effects of physical activity during pregnancy must examine specific components of the activity, rather than relying on formal employment as a proxy for exposure.

Institute of Medicine maternal weight gain recommendations and pregnancy outcome in a predominantly Hispanic population.

OBJECTIVES: To describe gestational weight gain patterns by pre-pregnancy weight and trimester of pregnancy, and to examine the risk of preterm birth associated with pre-pregnancy weight and gestational weight gain using various definitions of adequacy based on the Institute of Medicine (IOM) standard. METHODS: We used data collected prospectively from 8736 pregnant women receiving care in public health clinics in the West Los Angeles area. Pre-pregnancy weight was based on self-report obtained at the initial visit. Maternal weight was measured at each prenatal visit, allowing for the calculation of total weight gain and the rate of weight gain during each trimester. RESULTS: Women underweight before pregnancy (body mass index less than 19.8) had the greatest risk of delivering preterm (crude relative risk 1.7, P < .05). Similarities in patterns of weight gain were seen between women of low weight and normal pre-pregnancy weight status, as well as between overweight and obese women. Compared to the IOM recommendations for total weight gain, 47.8% of underweight women and 36.6% of normal-weight women gained the recommended amount. In contrast, 52% and more than 75% of overweight and obese women, respectively, had excessive gains. Inadequate weight gain during the third trimester as opposed to excessive gain, defined specifically for each pre-pregnancy weight status, was predictive of preterm birth. CONCLUSIONS: Weight monitoring during pregnancy continues to have clinical applications for the prediction of poor birth outcomes. Weight gain less than 90% the IOM recommendation in the third trimester may serve as an indicator for identifying women at risk of delivering preterm.

The infant's ability to self-regulate caloric intake: a case study.

A case study which illustrates the infant's ability to regulate caloric intake through adjustments in formula intake is presented. A daily record of infant formula and supplemental food intake of a normal, bottle-fed male infant was kept from 1 week to 9 months after birth. The infant's physical growth was assessed at regular intervals. Measurements included weight, recumbent length, head circumference, and skinfold thicknesses. Feeding was ad libitum, and caregivers were highly responsive to the infant's satiety behaviors. Under these conditions, the infant adjusted his caloric intake as supplemental foods were added to his diet by progressively decreasing the volume of formula consumed. His growth was well canalized and tracked very close to the 50th centile of NCHS weight and length standards. The regularity of his growth attests to the adequacy of his intake for meeting energy needs without excess energy storage. This suggests that to avoid overfeeding the bottle-fed infant, caregivers should attempt to facilitate the infant's self-regulation of intake.

Defining the "urban" in urbanization and health: a factor analysis approach.

Urban environments have been linked to a range of human health issues, and as the pace of urbanization accelerates, new challenges arise to characterize these environments, and to understand their positive and negative implications for health. We seek to contribute to future studies of urbanization and health by exploring multiple definitions of urbanicity in the Philippines, using data from an ongoing, longitudinal study. We use factor analysis to identify meaningful clusters of household- and community-level variables, and to generate factor scores that summarize each household's position with respect to access to infrastructure and health services, and level of affluence. Factor scores are considered for 1983 and 1994 to assess the type and pace of change that has occurred in the Philippines, and scores are compared across urban and rural areas, and across six different settlement types, to explore household- and community-level markers of urbanicity. This analysis demonstrates the heterogeneity of environments within urban and rural areas, and emphasizes the need for a finer level of investigation in future studies of urbanization and health.