Martha Kaufer-Horwitz

Association between measured BMI and self-perceived body size in Mexican adults.

Aim: The study examined the association between perceived body size (through self-selection of Stunkards body shape silhouettes) and measured body mass index (BMI) in Mexican Mestiso adult men and women, and determined the BMI values that corresponded to each silhouette. Subjects: A sample of 1092 men and 1247 women, apparently healthy, aged 20–69, was studied. Methods: Participants were asked to identify the silhouette that most accurately represented his/her body size. Weight and height were measured in duplicate to calculate BMI. A simple linear regression analysis was used to adjust BMI values to silhouette categories by gender. Areas under the receiver operating characteristic curves (AUC) were calculated to assess accuracy. Results: Gender-specific BMI values for each silhouette were obtained. Correlation coefficients between silhouette ratings and BMI were 0.702 in males and 0.766 in females. Overweight ranged from silhouette 4 to 6 and obesity from silhouette 6 to 9, in both men and women. In the regression models, 49.3% of BMI variance in males and 58.7% in females were explained statistically by silhouette self-selection. AUC were higher than 0.8 for overweight and obesity in males and females. Conclusions: Both male and female models had a good fit, indicating that BMI can be associated with body shape silhouettes. Silhouettes can be useful for defining overweight and obesity in settings such as schools or worksites, or where scales and stadiometers might not be available. They can also be used to provide health advice to the public.

Comparison of three procedures for assessing fetal growth in neonates born in Mexico City

Objective: To assess if three diagnostic criteria (DC) of alteration of fetal growth can be used interchangeably. Methods: We studied 1812 consecutive live singleton births, free of malformations, whose mothers received prenatal care and had certainty on date of last menstrual periods. Sensitivity and specificity were determined for: birth-weight <2500g (LBW), birth-weight <P10 of birth-weight for gestational age and sex according to local standards (IUGRJ) and to Lubchenco (IUGRL). Each DC was used alternately as reference. Results: With LBW as reference, sensitivities were low for IUGRJ and IUGRL (47.4%, 19.3%) for preterm neonates, and high (98.9%, 80.6%) for term neonates; specificities were high (95.5%-100%) for all DC. With IUGRJ as reference, LBW showed 100% sensitivity and 44.5% specificity; IUGRL showed 40.6% sensitivity and 100% specificity in preterm neonates. Both criteria showed fair sensitivity and high specificity in term neonates. Conclusion: DC cannot be used interchangeably to assess fetal growth status at birth.

Association of anthropometric birth measurements and blood pressure in the first year of life

In order to identify associations between anthropometric condition at birth and blood pressure in the first year of life, we designed a cross-sectional study, where systolic and diastolic blood pressures were measured in 438 children who attended a pediatric follow-up clinic in one year. Measurements at birth were obtained from the clinical files at the Instituto Nacional de Perinatologia. Anthropometric data at birth were analyzed as crude values and values adjusted for gestational age at birth, while blood pressure values were also analyzed in crude form or adjusted for gender and age at time of evaluation. Intrauterine Growth Retardation was present in 61% of the children; all indicators evaluated with the exception of crude diastolic blood pressure were significantly different between growth-retarded and normal infants. All the anthropometric measurements showed a significantly positive correlation with crude blood pressure values, while all correlations were significantly negative with gender and age adjusted systolic and diastolic blood pressures. Stepwise regression analysis showed predictive associations of % head circumference at birth for diastolic blood pressure; % birth weight for adjusted diastolic blood pressure; and % head circumference at birth and birth length for crude as well as for adjusted systolic blood pressure. It can be concluded that anthropometric condition at birth may affect blood pressure during the first year of life.