Anthropometric measures as a predictor of cephalopelvic disproportion

This study compared three body measurements, height, hip width (bitrochanteric) and foot length, in 120 Hispanic women who had their first birth by cesarean section (N = 60) or by spontaneous vaginal delivery (N = 60). The objective of the study was to see if there were differences in these measurements that could be useful in predicting cephalopelvic disproportion. Data were collected from two public hospitals in Houston Texas over a 10 month period from December 1994 to October 1995. The statistical technique used to evaluate the measures was discriminant analysis.^ Women who delivered by cesarean section were older, shorter, had shorter feet and delivered heavier infants. There were no differences in the bitrochanteric widths of the women or in the mean gestational age or Apgar scores of the infants.^ Significantly more of the mothers and infants were ill following cesarean section delivery. Maternal illness was usually infection; infant illness was primarily infection or respiratory difficulties.^ Discriminant analysis is a technique which allows for classification and prediction to which group a particular entity will belong given a certain set of variables. Using discriminant analysis, with a probability of cesarean section 50 percent, the best combination to classify who would have a cesarean section was height and hip width, correctly classifying 74.2 percent of those who needed surgery. When the probability of cesarean section was 10 percent and probability of vaginal delivery was 90 percent, the best predictor of who would need operative delivery was height, hip width and age, correctly classifying 56.2 percent. In the population from which the study participants were selected the incidence of cephalopelvic disproportion was low, approximately 1 percent.^ With the technologic assistance available in most of the developed world, it is likely that the further pursuit of different measures and their use would not be of much benefit in attempting to predict and diagnose disproportion. However, in areas of the world where much of obstetrics is "hands on", the availability of technology extremely limited, and the incidence of disproportion larger, the use of anthropometric measures might be useful and of some potential benefit. ^

Cardiovascular diseases risk factors during the first year of life

The pattern of change in cardiovascular risk factors, blood pressure (SBP and DBP) and plasma total cholesterol (TC), over time, their tracking and their relation to anthropometric measurements during the first year of life were investigated. Also, the effect of breast feeding on TC and the relationship of blood pressure measurements and family history of CVD risk factors were examined. One hundred five newborn term, healthy infants who were seen at a pediatric clinic in The Woodlands, Texas were followed longitudinally from 2 weeks to 1 year of age. TC, blood pressure, weight and length of the infants were measured at age 2 weeks, and again at 2, 4, 6, 9 and 12 months. In addition, family history, maternal and paternal, of CVD risk factors was obtained. Data analyses included only 40 infants who completed one year of follow up.^ At 2 weeks of age, the median value for TC was 23 mg/dl higher for females than for males. This difference disappeared as infants got older. For males, most of the increase in TC median levels, from 114 to 137 mg/dl, occurred between the ages of 2 weeks and 2 months, whereas for the female group, TC levels increased moderately, about 10 mg/dl, between 9 and 12 months of age. Tracking of TC was examined by using Spearman's correlation analysis. There were strong correlations between measurements taken as early as 2 weeks of age with later measurements. These correlations were stronger and more significant for males than for females (for males, r varied between 0.51 to 0.70, whereas for females, r varied between 0.11 to 0.70). The association of body measurements with TC is no more than modest and is closer for female infants than for male infants. Analysis, also, showed that infants who received breast milk had a TC mean value 47 mg/dl higher than that for infants who received formula milk only during the period of breast feeding and this difference disappeared by age 12 months.^ In both genders, most of the increase in blood pressure (about 10-15 mmHg in both SBP and DBP) occurred during the first 4 months of life. Most of the increase for male infants occurred during the first 2 months of life, while for females, the increase in SBP and DBP was between the age of 2 and 4 months. Neither SBP nor DBP track well during the first year of life and most of the correlations between measurements at different ages were not significant for either gender. The cross-sectional relationship of blood pressure measurements and selected body measurements was assessed. For females, only at age of 12 months did DBP have positive and significant correlations with weight, length and Quetelet index (r = 0.57, 0.60 and 0.57, respectively). There were no significant correlations between blood pressure and body measurements for males. Finally, analysis showed that maternal history of CV risk factors was significantly related to SBP in the female infant group, but not for males. For DBP, neither maternal nor paternal history was related. ^

Growth and development of body fat distribution from skinfold measurements: Longitudinal principal components

Longitudinal principal components analyses on a combination of four subcutaneous skinfolds (biceps, triceps, subscapular and suprailiac) were performed using data from the London Longitudinal Growth Study. The main objectives were to discover at what age during growth sex differences in body fat distribution occur and to see if there is continuity in body fatness and body fat distribution from childhood into the adult status (18 years). The analyses were done for four age sectors (3mon-3yrs, 3yrs-8yrs, 8yrs-18yrs and 3yrs-18yrs). Longitudinal principal component one (LPC1) for each age interval in both sexes represents the population mean fat curve. Component two (LPC2) is a velocity of fatness component. Component three (LPC3) in the 3mon-3yrs age sector represents infant fat wave in both sexes. In the next two age sectors component three in males represents peaks and shifts in fat growth (change in velocity), while in females it represents body fat distribution. Component four (LPC4) in the same two age sectors is a reversal in the sexes of the patterns seen for component three, i.e., in males it is body fat distribution and in females velocity shifts. Components five and above represent more complicated patterns of change (multiple increases and decreases across the age interval). In both sexes there is strong tracking in fatness from middle childhood to adolescence. In males only there is also a low to moderate tracking of infant fat with middle to late childhood fat. These data are strongly supported in the literature. Several factors are known to predict adult fatness among the most important being previous levels of fatness (at earlier ages) and the age at rebound. In addition we found that the velocity of fat change in middle childhood was highly predictive of later fatness (r $\approx -$0.7), even more so than age at rebound (r $\approx -$0.5). In contrast to fatness (LPC1), body fat distribution (LPC3-LPC4) did not track well even though significant components of body fat distribution occur at each age. Tracking of body fat distribution was higher in females than males. Sex differences in body fat distribution are non existent. Some sex differences are evident with the peripheral-to-central ratios after age 14 years. ^

Impact of oral contraceptives on weight, body composition, and cardiovascular disease risk factors in women age 18--30 years participating in a 15-week exercise program

Objective. To assess differences in body weight, body composition, total cholesterol, blood pressure, and blood glucose between OC users and non-users age 18-30 y before and after a 15-week cardiovascular exercise program in Houston, TX from 2003 to 2007.^ Study Design. Secondary analysis of prospective data. ^ Study Subjects. 453 Non-Hispanic white (NHW), Hispanic, and African American (AA) women age 18-30 y with no previous live birth, a history of menstruating, no use of other hormonal contraceptives or medications, no menopause or hysterectomy, and no current pregnancies.^ Measurements. Demographic data, medication use, and menstrual history were assessed via self-administered questionnaires at baseline. Anthropometric and laboratory measures were taken at baseline and 15-weeks. ^ Data Analysis. Linear regression assessed the association between OC use and study variables at baseline, and the change in study variables from baseline to 15-weeks. Logistic regression assessed the association between OC use and CVD risk. Each analysis was also stratified by race/ethnicity. ^ Results. At baseline, OC users had higher total cholesterol (p<.0005) and were above cholesterol risk cut points for CVD (OR=4.3, 95% CI=2.4-7.7) compared to non-users. At baseline, OC use was also associated with higher diastolic blood pressure (p=.018) compared to non-users, primarily in non-Hispanic whites (p=.007). OC use was associated with lower blood glucose compared to non-users in Hispanics only (p=.008). OC use was associated with absolute change in diastolic blood pressure (p=.044) and total cholesterol (p=.003). There was evidence that OC use may affect individuals differently based on race/ethnicity for certain obesity and CVD risk factors.^ Conclusions. OC users and non-users responded similarly to a 15-week cardiovascular exercise program. Exceptions included a greater change in diastolic blood pressure and total cholesterol among NHW and Hispanic OC users compared to non-users after exercise intervention. At baseline, OC use was associated with diastolic blood pressure and was most strongly associated with increased levels of total cholesterol. OC users were at greater risk of having total cholesterol above CVD risk cut points than non-users.^

Physical activity, body composition, exogenous estrogen use and their association with insulin-like growth factors

Obesity and physical inactivity are modifiable risk factors that are associated with several health issues; they are major factors in up to 30% of major cancers. Elevated levels of circulating insulin-like growth factor-I (IGF-I) have been associated with high body composition measurements and high cancer risk; exogenous estrogen use is associated with low circulating IGF-I levels and high cancer risk. The relationship between physical activity and circulating IGF levels is complex and findings of previous studies of their relationship remain inconsistent; however, these studies included vague definitions of physical activity. In this study, we used cross-sectional data from the Women's Health Initiative to determine the relationship between specific measures of physical activity (e.g., intensity, duration, and frequency) and circulating IGF-I levels, accounting for exogenous estrogen use and body composition. These data were collected from women enrolled at Women's Health Initiative clinical centers at Baylor College of Medicine and Wake Forest University School of Medicine. Multivariate linear regression analysis showed that circulating IGF-I and IGF-binding protein (BP) 3 levels were positively associated with frequency, duration, and intensity of physical activity. Circulating IGF-I levels and the molar IGF-I:IGF-BP3 ratio were significantly associated with frequency of walking, whereas circulating IGF-BP3 levels were significantly associated with strenuous physical activity, suggesting that different aspects of physical activity and their effects on fitness affect members of the IGF family differently. The results from our study support the recommendation of a regular exercise routine, particularly that of strenuous intensity, for postmenopausal women as a means to prevention of cancer.^

Total cholesterol and anthropometric measurements distributions in a cross-sectional study of school children

Cross-sectional age and sex specific distributions of serum total cholesterol were described for 1091 children age 6-18 years, in The Woodlands, Texas. Associations of serum total cholesterol with five anthropometric measurements (weight, height, body mass index, arm circumference, and triceps skinfold thickness) were examined by correlation and regression analyses. Examination of serum total cholesterol distributions showed lower levels in boys than in girls for most of the age groups studied. Mean levels of total cholesterol peaked at age 9 for boys and 8 for girls. Serum total cholesterol leveled off until age 14 for boys and 11 for girls, and then dropped through age 18 for both boys and girls. These results support the hypothesis that serum total cholesterol concentration drops at pre-adolescence.^ Age adjusted correlations were observed between serum total cholesterol and triceps skinfold thickness for both boys and girls. This association was stronger in boys. Triceps skinfold thickness and arm circumference were consistently the strongest correlates for serum total cholesterol in boys. Weight and arm circumference were consistently the strongest correlates for serum total cholesterol in girls. ^