[Behavior of some anthropometric, clinical and biochemical variables in boys and girls 8 to 12 years of age from the longitudinal study of the metropolitan area]. / Comportamiento de algunas variables antropométricas, clinicas y bioquimicas en varones y hembras de 8 a 12 años de edad del Estudio Longitudinal del Area Metropolitana.

A longitudinal principal components analysis was used to summarize trends or intraindividual changes in weight, height, blood pressure, serum cholesterol and triglycerides in 32 boys and 28 girls from the Caracas Longitudinal Study (1976-1982), who started follow-up at age 8. A first component was identified for each variable, it represents a measure of position across the whole age period, a "canalization pattern". This component accounted for most of the total variance. The second component represents an unidirectional change in relative position of the values of the variable, a "decanalization pattern", and a third pattern summarized deviations around a position level: "recanalization pattern". The results from the correlation analyses between the components indicate a positive and significant association between the identified trends. These patterns allow predictability of "high and low risk" factors of non-communicable chronic diseases.

[Relation among early maturation, body mass index and the longitudinal behavior of systolic blood pressure]. / Relación entre la maduración temprana, indice de masa corporal y el comportamiento longitudinal de la presión arterial sistólica.

In the Caracas Longitudinal Study, 53 girls- 8 to 11 years of age- who had been classified as early, average and late maturers were analyzed longitudinally with respect to Body Mass Index (BMI) and Systolic Blood Pressure (SBP). A longitudinal principal component analysis was used to summarize trends or intraindividual changes in BMI and SBP. A first component was identified for BMI, this component accounted for most of its total variance (94.65%). Girls were classified as normal in weight or at risk of overweight on the basis of this component. Three principal components were identified for SBP, that accounted for 91.83% of the total variance of this variable. The first component represented a measure of position across the whole age period, a "canalization pattern"; this component accounted for most of the total variance (45.65%). The second component revealed an unidirectional change in relative position of the values of the variable, a "decanalization pattern", and a third pattern summarized deviations around a position level: "recanalization pattern". Girls who showed a canalization pattern for SBP were those identified as early maturers and at risk of overweight.