Maternal body composition in relation to infant birth weight and subcutaneous adipose tissue

Infant birth weight has increased recently, representing an obstetric and potentially a public health problem since high birth weight involves a risk of obesity later in life. Maternal nutritional status is important for fetal growth and therefore relationships between maternal body weight and composition v. birth weight and infant subcutaneous adipose tissue were investigated in twenty-three healthy women and their newborn infants using multiple and simple linear regression analysis. Furthermore, using previously published data for nineteen infants, it was demonstrated that an anthropometric method could provide useful estimates of the amount of subcutaneous adipose tissue. Birth weight was correlated with the maternal content of total body fat (TBF) both before pregnancy and in gestational week 32 and, together with gestational age at birth, TBF (%) before pregnancy explained 45% of the variation in birth weight. This figure was not increased when gestational gains in weight or TBF were added to the model. Furthermore, in infants, birth weight correlated with the amount of their subcutaneous adipose tissue. Together maternal TBF (%) and amount of subcutaneous adipose tissue in infants explained 61-63% of the variation in birth weight while the amount of infant subcutaneous adipose tissue alone explained only 55%. The maternal TBF content is likely to be important for the recent increase in birth weight. This factor probably causes a general augmentation in fetal growth rather than a specific stimulation of adipose tissue growth.     

Programming of body composition by early growth and nutrition

There is now compelling evidence that growth patterns in early life are associated with risk of the metabolic syndrome in adulthood, although the relative importance of prenatal v. postnatal growth for such associations remains controversial. Body composition may play a key role in the 'programming' of such diseases, through itself being programmed by early growth, and perhaps also by being a mediator of the programming process. Early studies reporting positive associations between birth weight and adult BMI suggested a tendency for large babies to become obese adults. Such findings appeared contradictory to the many studies linking low birth weight with increased risk of the metabolic syndrome. Recent studies now indicate that birth weight is strongly predictive of later lean mass, and has a much weaker association with later fatness. Studies that link low birth weight with a more central adipose distribution in later life remain controversial, and require confirmation using more sophisticated methodologies. Findings for infant growth rate appear population-specific, with infant weight gain predicting subsequent lean mass in developing countries, but predicting subsequent fat mass and obesity in industrialised populations. Further studies are required on this issue, to ensure that appropriate public health policies are recommended for countries across the range of economic development. Although the links between early growth and later disease risk implicate early-life nutrition, either in utero or during infancy, few prospective studies have explored the influence of early diet on later body composition. Many studies have associated breast-feeding with a reduced prevalence of obesity categorised by BMI; however, the few studies directly evaluating childhood fatness provide little support for this hypothesis. Recent advances in the ability to measure body composition during the infant period offer a major opportunity to improve the understanding of the nutritional programming of body composition and its contribution, or lack thereof, to subsequent disease risk.     

Fecundability in relation to body mass and menstrual cycle patterns.

Few studies have investigated the association between body mass index and fecundability, that is, the ability to conceive in a menstrual cycle, among fertile women with normal menstrual cycle pattern. We examined the independent and combined effects of duration and regularity of the menstrual cycle, body mass index, and fecundability from records on pregnant women attending antenatal care at Odense University Hospital, Denmark, between 1972 and 1987. We included only the first birth of each woman who had planned pregnancies and no pre-pregnancy disease (N = 10,903). We estimated the fecundability odds ratio (FR) as the odds of conception in a menstrual cycle. After adjusting for confounders, the fecundability for women with a body mass index >25 kg/m2 was lower than for women with a body mass index of 20-25 kg/m2 [FR = 0.77; 95% confidence interval (CI) = 0.70-0.84]. FR was lower for women with long (>35 days) (FR = 0.74; 95% CI = 0.63-0.87) or irregular cycles (FR = 0.78; 95% CI = 0.70-0.87), even when their body mass index was within the normal range (20-25 kg/m2) and/or their cycles were regular.     

Diet and insulinlike growth factor I in relation to body composition in women with exercise-induced hypothalamic amenorrhea.

To assess the potential influence of diet and endogenous peptide anabolic hormone secretion on exercise-related differences in body composition, we compared levels of macronutrient intake, insulinlike growth factor I (IGF-I), and fat-free mass (FFM) and fat mass (FM) in matched groups of exercising women with and without secondary hypothalamic amenorrhea. Women were tightly matched according to somatotype and grouped into those with exercise amenorrhea (EXam, n = 6), exercise eumennorhea (EXeu, n = 5), and sedentary eumennorheic controls (SED, n = 5). Although no between-group difference was observed in FFM, the EXeu subjects had a significantly lower fat fraction and a significantly elevated FFM/FM ratio. Kilocaloric and protein intakes did not differ between groups, but dietary fat intake was lowest and carbohydrate intake highest in the EXam subjects. Dietary macronutrients were not correlated with the FFM/FM ratio. However, levels of insulinlike growth factor I were significantly correlated to the FFM/FM ratio and there was a clear trend for the hormone to be highest in the EXeu subjects. We conclude that differences in body composition between exercising women with and without exercise-induced hypothalamic-pituitary dysfunction were related to an alteration in IGF-I secretion, although differences in macronutrient intake might also be a factor. Further studies are warranted to elaborate upon the dietary and hormonal factors regulating the body composition response to exercise.     

Women intending to breastfeed: predictors of early infant feeding experiences

We conducted interviews prenatally and postpartum with 187 women, all of whom intended to breastfeed their newborns. However, 18% of these women either never initiated breastfeeding or stopped within one week. Among women who initiated breastfeeding, we identified four variables as significant predictors of failure to breastfeed for more than seven days: lower confidence in ability to breastfeed, less certainty in the decision to breastfeed, delayed first breastfeeding experience, and lack of rooming in with the baby. Results of this study suggest that women at high risk for not implementing their prenatal breastfeeding intention can be identified for additional support; interventions should focus on prenatal confidence building, early and continuing contact with the newborn, anticipatory guidance prior to discharge, and early pediatric follow-up.     

Size at birth, infant, early and later childhood growth and adult body composition: a prospective study in a stunted population

BACKGROUND: Pre-natal and post-natal growth are associated with adult body composition, but the relative importance of growth in different periods of childhood is still unclear, particularly in stunted populations. METHODS: We studied 358 women and 352 men measured as children in 1969-77 in four villages in Guatemala, and re-measured as adults in 2002-04 (mean age 32.7 years). We determined the associations of body mass index (BMI) and length at birth, and changes in BMI and length during infancy (0-1.0 year) and early (1.0-3.0 years) and later (3.0-7.0 years) childhood, with adult BMI ((a)BMI), percentage of body fat ((a)PBF), abdominal circumference ((a)AC) and fat-free mass ((a)FFM). RESULTS: Prevalence of stunting was high (64% at 3 years; HAZ < -2SD). Obesity (WHZ > 2SD) prevalence in childhood was <2%, while overweight prevalence in adulthood was 52%. BMI at birth was positively associated with (a)BMI and (a)FFM while length at birth was positively associated with (a)AC and (a)FFM. Increased BMI in infancy and later childhood were positively associated with all four adult body composition measures; associations in later childhood with fatness and abdominal fatness were stronger than those with (a)FFM. Change in length during infancy and early childhood was positively associated with all four adult body composition outcomes; the associations with (a)FFM were stronger than those with fat mass. CONCLUSIONS: Increases in BMI between 3.0 and 7.0 years had stronger associations with adult fat mass and abdominal fat than with (a)FFM; increases in length prior to age 3.0 years were most strongly associated with increases in (a)FFM.     

Sleeping metabolic rate in relation to body composition and the menstrual cycle.

The relationship between sleeping metabolic rate (SMR) measured from 0300 to 0600 h in a respiration chamber and body composition was studied in 47 healthy adult subjects (23 men and 24 women). The effect of the menstrual cycle on SMR was examined in 16 of the 24 women. SMR increased in the postovulation phase of the menstrual cycle (estimated as days 18-29 after last menstruation) 7.7% on average (P less than 0.001). A stepwise regression showed that both fat-free mass (FFM), fat mass (FM), and the phase of the menstrual cycle contributed significantly to SMR. After adjustment for FFM and FM, no sex differences in SMR (men vs preovulation women) remained. The inclusion of FM in this model is an improvement that eliminates the sex difference in SMR/FFM that is usually found. A prediction equation is given that explains 85% of the variance in SMR among individuals.     

Effect of feeding frequency on growth and body composition of gastrostomized rat pups

Two groups of rat pups were gastrostomized at 24 hours of age and formula-fed each hour or once every 6 hours a daily intake equal to 33% of their body weight. They were killed at age 5 to 7 days when body weight had reached twice that at time of gastrostomy; organ weights, body composition and hepatic activity of glucose-6-phosphate-dehydrogenase (G-6-PD) and alpha-glycerophosphate dehydrogenase (alpha-GPD) were determined. The stomach, small intestine, liver and spleen of pups fed 4 times each day were significantly larger than those of pups fed hourly. Food efficiency (gain/kcal) of pups fed each hour was significantly greater than that of pups fed every 6 hours; however, because pups fed each hour gained more water and less fat, an estimate of the percentage of energy intake utilized for growth was significantly less for these animals than for those fed every 6 hours. Concentration of calcium was greater and concentration of sodium was less in the carcasses of pups fed each hour than in the carcasses of pups fed 4 times daily. Total liver activities of G-6-PD and alpha-GPD were significantly less in pups fed each hour but the activity of these enzymes expressed per milligram of liver protein did not differ significantly between the two feeding groups.     

Nutrition survey in Tabasco, Mexico: patterns of infant feeding

Information on infant feeding was collected from 149 mothers of 744 children born over a period of 25 yr in an area of Tabasco, Mexico which has experienced rapid economic development. From 1953 to 1978, there was an increase in bottle-feeding, primarily as a supplement to breast-feeding, while the proportion of infants exclusively breast-fed declined from 69 to 48%. This trend was accompanied by a decrease in the average duration of lactation: the percentage of infants breast-fed 12 months or more declined from 73 to 45%. Mothers living within the area of an agricultural development project completed in 1973 were more likely to bottle-feed than mothers outside the project. The consequences of supplemental bottle-feeding for continued lactation, infant health, and child spacing require further investigation.     

Diet and insulinlike growth factor I in relation to body composition in women with exercise-induced hypothalamic amenorrhea

To assess the potential influence of diet and endogenous peptide anabolic hormone secretion on exercise-related differences in body composition, we compared levels of macronutrient intake, insulinlike growth factor I (IGF-I), and fat-free mass (FFM) and fat mass (FM) in matched groups of exercising women with and without secondary hypothalamic amenorrhea. Women were tightly matched according to somatotype and grouped into those with exercise amenorrhea (EXam, n = 6), exercise eumennorhea (EXeu, n = 5), and sedentary eumennorheic controls (SED, n = 5). Although no between-group difference was observed in FFM, the EXeu subjects had a significantly lower fat fraction and a significantly elevated FFM/FM ratio. Kilocaloric and protein intakes did not differ between groups, but dietary fat intake was lowest and carbohydrate intake highest in the EXam subjects. Dietary macronutrients were not correlated with the FFM/FM ratio. However, levels of insulinlike growth factor I were significantly correlated to the FFM/FM ratio and there was a clear trend for the hormone to be highest in the EXeu subjects. We conclude that differences in body composition between exercising women with and without exercise-induced hypothalamic-pituitary dysfunction were related to an alteration in IGF-I secretion, although differences in macronutrient intake might also be a factor. Further studies are warranted to elaborate upon the dietary and hormonal factors regulating the body composition response to exercise.     

Determinants of infant feeding method in relation to risk factors for breast cancer

BACKGROUND: Breastfeeding is considered to be an important factor for maternal and children's health. However, the epidemiological findings related to the effect of breastfeeding on women's health, especially with respect to breast cancer development, are inconsistent. Determinants of infant feeding method may contribute to the inconsistency. METHODS: A total of 24,769 women aged 40-64 in Miyagi Prefecture, Japan, responded to a self-administered questionnaire survey in 1990. Using the data obtained from 22,085 parous women, we calculated odds ratios (ORs) for the choice of "breastfeeding only" during reproductive period. RESULTS: Late age at menarche (> or = 16 years, OR = 1.57) and high body mass index (BMI) at 20 years of age (> or = 24, OR = 1.31) were associated with the choice of breastfeeding only. Late age at birth of first child (> or = 28 years, OR = 0.29), history of breast cancer in mother (OR = 0.68), and high educational level (more than a high school education, OR = 0.53) reduced the possibility of choosing breastfeeding only. CONCLUSION: The results indicate that the choice of infant feeding method is associated with several breast cancer risk factors. Based on this finding, we should construct appropriate breast cancer risk models for parous women and investigate the changes in the effects of breastfeeding and other breast cancer risk factors among these risk models. Especially in a risk model controlling for breastfeeding, the effects of other breast cancer risk factors should be reevaluated. Through comparisons among different risk models, we may find the best-fitted risk model and identify the true effect of breastfeeding.     

Basal metabolic rate in anorexia nervosa: relation to body composition and leptin concentrations

BACKGROUND: Leptin is thought to represent a peripheral signal involved in the regulation of energy balance. Its action has been studied in animals and obese subjects. Little is known about leptin's role during negative energy balance. OBJECTIVE: The objective was to evaluate the relation between energy turnover, body composition, and plasma leptin concentrations in anorexia nervosa (AN). DESIGN: Sixteen weight-stable women with AN were compared with 22 control subjects and 14 rehabilitated AN patients (R-AN). Basal metabolic rate (BMR) was measured by indirect calorimetry; fat-free mass (FFM) and fat mass (FM) were calculated according to a 4-compartment model. Plasma leptin was determined by radioimmunoassay. RESULTS: The BMR of AN patients (2.73 +/- 0.37 kJ/min) was significantly lower than that of control subjects (3.45 +/- 0.34 kJ/min) (P < 0.001), even after adjustment for FFM (2.92 +/- 0.33 kJ/min in AN patients and 3.30 +/- 0.26 kJ/min in control subjects; P < 0.004). Plasma leptin concentrations in AN patients were 76% lower than in control subjects, even after body fat was controlled for. In R-AN patients, BMR was not significantly different from that of control subjects and leptin concentrations were generally close to normal. Plasma leptin concentrations correlated significantly with FM (r(2) = 0.53, P < 0.0000) and BMR, even after adjustment for FFM (r(2) = 0.21, P < 0.0003). CONCLUSIONS: BMR and plasma leptin concentrations are depressed in patients with AN; this is not explained by body-composition changes. The relation between leptin and BMR suggests that leptin plays a role in the energy sparing response to exposure to chronic energy deficiency. The return of BMR to normal and the significant increase in leptin concentrations in R-AN patients suggests a full reversibility of this adaptation mechanism.     

Associations of birthweight and infant growth with body composition at age 15--the COMPASS study

Size at birth and postnatal growth have been positively associated with obesity in adulthood. However, associations between postnatal growth and body composition later in life have rarely been studied. The overall purpose was to explore the associations between birthweight, weight gain during first year of life and height, weight, body mass index, fat free mass index (FFMI), fat mass index, % fat mass (FM) and waist circumference in adolescence. The COMPASS study is a population-based study of adolescents from a well-defined area in Stockholm County, Sweden. Birth characteristics and weight during childhood were collected from registers and child health centre records, and body composition at age 15 years was measured by bioelectric impedance by trained nurses. Complete data were available for 2453 adolescents. Associations between predictor and outcome variables were assessed with linear regression modelling. Birthweight was positively associated with all outcome variables, except for %FM among girls. FFMI increased by 0.49 kg/m(2)[95% CI 0.34, 0.63] (boys) and 0.25 kg/m(2)[0.12, 0.38] (girls) per 1 SD increase in birthweight. Increased weight gain in infancy showed strong, positive associations with all measures of body composition. FFMI increased by 0.73 kg/m(2)[0.60, 0.87] (boys) and 0.63 kg/m(2)[0.50, 0.76] (girls) per unit increase in weight z-score during first year of life. The effect of increased weight gain in infancy was not modified by birthweight. Birthweight and postnatal growth were both positively related to body composition in adolescence. Increased weight gain during the first year of life had stronger effect than prenatal growth, suggesting infancy to be a more critical period.