Héctor Herrera

HÁBITOS ALIMENTARIOS, ACTIVIDAD FÍSICA Y SU RELACIÓN CON EL ESTADO NUTRICIONAL-ANTROPOMÉTRICO DE PREESCOLARES

Preschool Venezuelan children underwent a study that measures the relationship between anthropometric nutritional state, food habits and physical activity level (PAL). Methods: Using Frisancho’s pattern as a reference, 173 children were studied, and anthropometric indicators such as height/age, weight/height and both lean and fat arm areas were measured. To assess food habits and PAL, a questionnaire was developed and applied. Results: For vegetables, fruits and fats the consumption patterns was low, and for cereals, meats, and dairy products was high. In 52% of the children the PAL was intense, and in the 27% was light. Among food habits, PAL and sedentary index (SI) an association was found. Conclusions: Results suggest implementing changes from the preschool stage to correct for inappropriate food habits, to encourage physical activity and to avoid a high SI, will relate to

Anthropometric measurements for assessing insulin sensitivity on patients with metabolic syndrome, sedentaries and marathoners.

The diagnosis of low insulin sensitivity is commonly done through the HOMA-IR index, in which fasting insulin and glucose blood levels are evaluated. Insulin and blood glucose levels are used for insulin sensitivity assessment by surrogate methods (HOMA-IR, Matsuda, etc), but anthropometric measurements like body weight, height and waist circumference are not considered, even if these variables also are related to low insulin sensitivity and metabolic syndrome. In this study we evaluate the impact of anthropometric measurements on the HOMA-IR, Matsuda and Caumo indexes to estimate insulin sensitivity. Specifically, we compare insulin sensitivity indexes with and without the anthropometric measurements in their equations on three different groups: patients with metabolic syndrome, sedentaries and marathoners. Results show relationships between anthropometric variables and insulin sensitivity indexes. On the other hand, subjects are mapped differently for insulin sensitivity assessment when anthropometric variables are taken into account. In addition, subjects diagnosed with normal insulin sensitivity could be considered as having low insulin sensitivity when anthropometric variables are considered.

Protocol for cardiac assessment of recreational athletes

In this work, the development of a database on physical fitness is presented. As initial population to fill this database, people who practice recreational sports at the Universidad Simon Bolivar (USB) were chosen. The goal was studying individual physical fitness in order to structure exercise routines that gives certain benefits without risking the individual health, promoting a less sedentary way of life. Before the study, a low-cost noninvasive protocol was designed to determine the level of physical fitness. The methodology consisted of four steps: a) A review of existing protocols to propose a set of physical fitness (International Physical Activity Questionnaire (IPAQ)), cardiovascular (heart rate variability, heart rate recovery time and arterial blood pressure), anthropomorphic, aerobic (maximum oxygen consumption) and mood state (Profile of Mood State (POMS)) measurements, which allow sketching a complete profile on the sportsman physical fitness. b) Instrumental data collection. c) Electrocardiographic signal processing. d) Data post-processing using multivariate analysis. The database was composed of 26 subject from USB. Ten subjects were soccer players, ten were mountain climbers and six were sedentary people. Results showed that the heart rate recover time after 2-3 min, IPAQ and maximum oxygen consumption have higher weights for classifying individuals according to their habitual physical activity. Heart rate variability, as well as, POMS did not contribute greatly for discriminating recreational sport from sedentary persons.

Random Sub-sampling Cross Validation for Empirical Correlation Between Heart Rate Variability, Biochemical and Anthropometrics Parameters

According to National Cholesterol Education Program-Adult Treatment Panel III, metabolic syndrome (MS) is a condition characterized by: Dyslipidemia, abdominal obesity, high levels in fasting glucose and arterial hypertension. Studies have explored indexes using dimensional analysis (DA) formed by anthropometric, biochemical and heart rate variability parameters for the diagnosis of MS. The dimensionless numbers made from DA have the capability to manage them as a mathematical functionality; therefore it is possible to relate them, even when the parameters used are not connected. The aim of this work is to find a polynomial equation using as variables two dimensionless numbers designed from anthropometrical and biochemical (πIS) parameters and from heart rate variability (πHRV) parameters. A fitting using a parametrical random sub-sampling cross validation (RSV) was performed using as an objective function the least squares method. A database of 40 subjects (25 control subjects and 15 subjects with MS) was employed. The polynomial parameters that best fit the database used correspond to a polynomial of order eight. The RSV substantially improves the adjustment of the polynomial compared to the application of the least squares method only (0.6678 vs. 0.3255). The polynomial relationship between πIS and πHRV allows the possibility to determine biochemical and anthropometric variables from heart rate variability parameters. Due to the limited number of subjects in the database used, it is necessary to repeat this methodology in a more extensive database to determine a more general polynomial that can be used with any type of population.

Heart rate variability analysis during a dehydration protocol on athletes

Athletes usually start the training with normal body water content, and then they dehydrate during exercise. The water deficit may contribute to increased heart rate and therefore impaired heart rate variability (HRV) postexercise. This paper presents a protocol to study the dehydration from the electrocardiographic signal in athletes, which comprised three phases: (i) Rest (RE): before any physical activity, (ii) post-exercise (PE): athletes performed a physical activity by pedaling a stationary bike, iii) post-hydration (PH): the subjects drank water ad libitum. In each phase, an electrocardiographic acquisition and weight measure were performed. In RE phase height was measured and in PE phase subjective effort perception of Borg was performed. The protocol was carried out in the morning. The sample consisted of 17 male athletes. The study of HRV in each of the electrocardiographic signals was performed by obtaining time-domain parameters (RR, RMSSD, SDRR), frequency-domain parameters (LF, HF) and non-linear parameters (SD1, SD2, approximate entropy and scaled exponents: α1 and α2). The findings in this paper imply that parameters: RR, RMSSD, SDRR, LF, HF, α2, SD1 and SD2 from HRV, are able to differentiate between phases of hydration and dehydration in the individual athlete, which could be used in the early detection of dehydration using the ECG signal, that is readily available and also noninvasively measure.