Esther Rebato

Comparison of predicted body fat percentage from anthropometric methods and from impedance in university students

The objective of the present study was to compare different methods for evaluating body fat percentage (BF%) (anthropometric methods and bioelectrical impedance analysis) in university students. Subjects were 653 healthy students whose mean age, body height, body weight and BMI were 21.1 (SD 2.5) years, 166.0 (SD 8.4) cm, 62.8 (SD 11.0) kg and 22.7 (SD 3.1) kg/m(2), respectively. Results showed that BMI is a poor predictor of body fatness since the sensitivity was low in comparison with the reference method (Siri equation). The lowest values of BF% were obtained using the reference method (Siri equation) (21.8 (SD 6.8)%). The two methods with the highest agreement were Siri and Lean (mean difference, -0.5), followed by Brozek (mean difference, -1.4) and Deurenberg (mean difference, -1.5). The largest mean difference for BF% was between Siri and impedance (-4.5). Although the methods and/or equations used in the present study have been commonly utilised to estimate BF% in young adults, the results must be interpreted with caution in the diagnosis and monitoring of overweight and obesity.

Genetic and environmental influences on growth from late childhood to adulthood: a longitudinal study of two Finnish twin cohorts.

Objectives: Human growth is a complex process that remains insufficiently understood. We aimed to analyze genetic and environmental influences on growth from late childhood to early adulthood.

Relationship between Somatotype and Blood Pressure in a Group of Institutionalized Venezuelan Elders

Background: Somatotype, as an indirect measure of estimating body composition, provides an easy and comprehensive picture of body shape. Multiple investigations have shown the existence of an association between somatotype components and cardiovascular disease. Objective: The aim of the present study was to examine the association of somatotype with blood pressure during ageing. Methods: The Heath-Carter anthropometric somatotype and both systolic (SBP) and diastolic (DBP) blood pressures were recorded. The sample included 809 healthy institutionalized elders (370 males and 439 females) from geriatric units in Caracas, Venezuela. Ages ranged from 60 to 102 years. Product-moment correlation coefficients between somatotype components and both blood pressure readings were calculated. Principal component analysis and homogeneity analysis by means of alternative least squares tests were also performed. Results: Females were more endomorphic and mesomorphic than males. Males were more ectomorphic than females. SBP showed a downward tendency with age in males, while in females the tendency was for the SBP to increase. Correlations among variables were from low to moderate and ranged from –0.37 to +0.34 in males, and from –0.18 to +0.32 in females. Correlations tended to be stronger in the younger age group and differences between sexes were found. A negative tendency in the correlation between ectomorphy and both SBP and DBP was found, except for the oldest age group, for which the correlation was positive. Endomorphy and mesomorphy showed a stable correlation pattern with blood pressure in males, while in females this pattern was more irregular and less consistent. Conclusion: Individuals with high levels of SBP and DBP had mean somatotypes, which were similar to those of other male groups characterized by myocardial infarct, coronary heart disease and the risk of hypertension, indicating that these somatotypes may be associated with cardiovascular risk factors. In particular, our results indicate that individuals who present a cardiovascular risk profile are more endomorphic and mesomorphic and less ectomorphic than those with a lower cardiovascular risk profile.

Overweight and Obesity: Prediction by Silhouettes in Young Adults

The present study analyzes the prevalence of overweight/obesity in a sample of young adults from the University of the Basque Country (Spain), and tests the efficiency of the silhouettes to predict overweight/obesity. This cross‐sectional study was conducted in a sample of volunteer university students from the University of the Basque Country (356 men and 745 women, age: 18–33 years), who came to the Physical Anthropology laboratory where a standardized questionnaire was administered and anthropometric measurements were taken by a well‐trained anthropometrist. Height and weight were obtained. BMI was calculated as weight/height2 (kg/m2) and it was used as a reference method. Using a questionnaire, based on the standard figural stimuli, subjects were asked to choose the silhouette which was closest to his/her usual appearance (current body size). The accuracy of the Williamson et al.s silhouettes as an overweight‐obesity indicator was analyzed by gender‐specific receiver operating curve (ROC). The cutoff figure to distinguish between nonoverweight and overweight‐obese individuals corresponded to number 7 in men and 6 in women. These cutoff values matched optimal sensitivity and specificity, with few nonoverweight subjects selecting silhouettes bigger than 7 in the case of men or 6 for women. In conclusion, the figural stimuli allows the identification of populations at overweight/obesity risk with the simple use of silhouettes, at least in this rank of age, where the overweight and obesity are yet little frequent.

Somatotype related to centripetal fat patterning of 8‐ to 19‐year‐old Basque boys and girls

The association between fat distribution and Heath‐Carter anthropometric somatotypes was studied in a sample of Basque children and youth aged 8–19 years. About mid‐adolescence, mean somatotype of Basque males changed, diminishing in endomorphy and mesomorphy, and increasing slightly in ectomorphy. For the same period, reduced mesomorphy was the most striking change in the female mean somatotype; meanwhile, there was an increase in endomorphy and a decrease in ectomorphy. Two groups of fat distribution were identified: centripetal and peripheral. Centripetal fat increased with age in both sexes. Fat distribution groups showed the following characteristics: a) mean somatotypes of centripetal and peripheral subjects were significantly different; b) centripetal boys and girls were extreme endomorphs prior to adolescent somatotype change; c) centripetal girls showed high ratings of endomorphy after adolescence; d) mesomorphy was related to a centripetal fat distribution pattern in both sexes; e) using the BMI as a criterion of obesity, only 16.3% of centripetal males and 21.8% of centripetal females were classified as obese; f) obesity was absent among subjects with a peripheral pattern, except for one male showing an endomorphic‐mesomorph somatotype; h) the obese showed extreme somatotypes with high endomorphy and mesomorphy, and minimal ectomorphy.

FAT DISTRIBUTION IN RELATION TO SEX AND SOCIOECONOMIC STATUS IN CHILDREN 4-19 YEARS

Fat distribution was studied in an urban sample of boys and girls 4.5 to 19.5 years from the Basque province of Biscay by means of Principal Component Analysis (PCA) of five skinfolds. The PCA extracted four components, which explained 99.1% of the total variance. The first principal component revealed strong stability across age and sex, and was related to a pattern of central body fat distribution. The three other components, upper‐lower trunk fat, lateral‐medial trunk fat, and upper‐lower extremity fat, showed poor stability due largely to the influence of age and, to a lesser degree, sex. In both sexes, individual scores of the four factors did not show multivariate differences by socioeconomic status when a MANOVA with age, age2 and age3 as covariates was done. Nevertheless, the first factor scores were significantly higher only in the poorer socioeconomic group of girls. The results are explained in the context of either different lifestyles related to socioeconomic status, a protective effect against environmental stress on urban males, or greater plasticity of trunk fat relative to extremity fat in females. Am. J. Hum. Biol. 10:799–806, 1998.

Quantitative genetics of human morphology and obesity-related phenotypes in nuclear families from the Greater Bilbao (Spain): Comparison with other populations

Background: It is well established that variation of soft-tissue traits is less influenced by the genetic component than skeletal traits. However, it is still unclear whether heritabilities (h2) of obesity-related phenotypes present a common pattern across populations. Aim: To estimate familial resemblance and heritability of body size, shape and composition phenotypes and to compare these results with those from other populations. Subjects and methods: The subject group consisted of 533 nuclear families living in Greater Bilbao and included 1702 individuals aged 2–61 years. Familial correlations and h2 were estimated for 29 anthropometric phenotypes (19 simple measures, three derived factors, four obesity indices and the three Heath-Carter somatotype components) using MAN and SOLAR programmes. Results: All phenotypes were influenced by additive genetic factors with narrow sense heritabilities ranging from 0.28–0.69. In general, skeletal traits exhibited the highest h2, whereas phenotypes defining the amount of adipose tissue, particularly central fat, were less determined by genetic factors. Conclusions: Familial correlations and heritability estimates of body morphology and composition from the Greater Bilbao sample were within the range observed in other studies. The lower heritability detected for central fat has also been found in some other populations, but further investigations in different populations using the same anthropometric traits and estimation methods are needed in order to obtain more robust conclusions.

Common variants in BDNF, FAIM2, FTO, MC4R, NEGR1, and SH2B1 show association with obesity-related variables in Spanish Roma population.

The objective of this study is to investigate the association between previously GWAS identified genetic variants predisposing to obesity in Europeans and obesity‐related phenotypes in Roma population.

Contribution of genetics and environment to craniofacial anthropometric phenotypes in Belgian nuclear families.

Abstract In this study we estimate relative genetic and environmental influences on head-related anthropometric phenotypes. The subject group consisted of 119 nuclear families living in Brussels, Belgium, and included 238 males and 236 females, ages 17 to 72 years. Two factor analyses with vari-max rotation (the first one related to facial measurements and the second one to overall head morphology) were used to analyze 14 craniofacial size traits. The resulting four synthetic traits [HFCF, VFCF, HDF1, and HDF2—horizontal (breadth) and vertical (height) facial factors and two head horizontal (breadth) factors, respectively] were used as summary variables. Maximum heritabilities (H2) were estimated for all studied traits, and variance components analysis was applied to determine the contribution of genetics and environment on the four craniofacial factors. In addition, we examined the covariations between the face (HFCF and VFCF) and head-related factors (HDF1 and HDF2), separately. Quantitative genetic analysis showed that HFCF, VFCF, HDF1, and HDF2 variation was appreciably attributable to additive genetic effects, with heritability (h2) estimates of 67.62%, 54.97%, 70.76%, and 65.05%, respectively. The three variance components reflecting a shared familial environment were nonsignificant for these four phenotypes. Bivariate analysis revealed significant additive and residual correlations for both pair of traits. The results confirm the existence of a significant genetic component determining the four craniofacial synthetic traits, and common genetic and environmental effects shared by the two face-related phenotypes and by the head-related ones.

Age at menarche from a Biscayan coastal population (Basque Country)

Data on menarcheal age were collected by the status quo method on a sample of 894 schoolgirls (9-19 years of age), from the Biscay province coast (Basque Country, Spain). Logit analysis provided a mean age at menarche of 12.75 +/- 0.04 years with a standard deviation of 0.93. The result was compared with data from another previous Basque study.