Search

Primary objective: The present research analyses a cross-sectional sample of 359 individuals (107 fathers, 107 mothers, 71 sons and 74 daughters) in 107 nuclear families from the Basque Country (Spain). The aim was the estimation of both transmissible and nontransmissible components acting on familial resemblance for stature, weight and body mass index (BMI). Methods: Standardized data of each generation and sex were adjusted to a BETA model of path analysis independent of sex effects, allowing the possibility of differentiating between transmissible (genetic and cultural) and non-transmissible (environmental) components acting on the observed phenotypic variance in Biscayan offspring. Results: The results supported the full model of familial transmission for the three variables, in addition to other reduced models that gave rise to transmission effects regardless of any influence from the siblings' shared environment on the environmental transmitted component from their parents (b = 0), and without genetic effects on the phenotype (h = z = 0). The most parsimonious model was accepted for weight and rejected for stature and BMI. The correlations existing between children and their mothers were higher than those with their fathers. Conclusion: The results confirmed the hypothesis of maternal effects influencing the inheritance of stature. [ABSTRACT FROM AUTHOR]

We analysed the Heath-Carter somatotype familial resemblance degree in a sample of 1350 siblings (685 males and 665 females) from 634 nuclear families in the province of Biscay (Basque Country, Spain). Sibling correlations were estimated according to maximum likelihood procedures for endomorphy, mesomorphy, ectomorphy and somatotypical attitudinal distance (SADi), after having adjusted for age, sex and the two other components (Model I), and after taking into account several environmental variables shared by all members of each sibship (Model II). All sibling correlations of the somatotype components were significant, tending to be higher in the case of mesomorphy than in the case of endomorphy. Same-sex siblings (BB and SS) displayed significant mesomorphic and ectomorphic resemblances, but in the case of endomorphy, sisters (SS) revealed relatively low correlation compared with brothers (BB). The sex of sibs had a significant influence on correlations of mesomorphy, but not on the other two components. Further control of socio-familial variables such as the father's occupation and education, and the sibship size, resulted in lower mesomorphy correlation coefficients, but had no effect whatsoever on the other two components. SADi correlations were very low and not significant, indicating high degrees of dispersion in the individual somatotypes of the sample. [ABSTRACT FROM AUTHOR]

The aim of this research was to analyse variation in body image perception and satisfaction by age, sex and nutritional status in an adult sample from the Basque Country, Spain. A case-control study was performed for 227 women and 178 men aged 18-70 years. Stunkard's silhouettes were used to evaluate Current Body Image (CBI) and Ideal Body Image (IBI), as well as dissatisfaction and inconsistency scores. Nutritional status was assessed following the WHO criteria for BMI in an adult population. The sample was divided into four groups based on sex and age (early adulthood <45 years, and middle/older adulthood ≥45 years). The Mann-Whitney U test was employed to evaluate sex and age differences, and the Gamma coefficient to assess the association between body image variables and nutritional status. Significant age differences in CBI (p<0.05) and sex differences in IBI (p<0.001) were detected. Both variables showed a positive association with BMI (p<0.01), which indicates that BMI is a biological characteristic related to body image satisfaction and influences participants' perception of themselves. Dissatisfaction scores showed that both sex and age differences (p<0.05) were negatively associated with BMI (p<0.001). Only participants ≥45 years presented sex differences in inconsistency scores (p<0.05); this variable was associated with BMI in women (p<0.01). Preferences in body image showed sexual dimorphism, with women preferring thinner bodies than men - a pattern observed in many Western populations - linked in part to sociocultural pressures. Women were more dissatisfied with their bodies than men; a higher dissatisfaction was observed in older relative to younger participants. The results confirm the association between nutritional status and body size perception and satisfaction, but also the relationship between nutritional status and the reliability with which women can classify themselves; in men, this relationship was not as clear.

The EHU12/24 (code of a survey from the University of the Basque Country/Euskal Herriko Unibertsitatea, UPV/EHU) study was designed to investigate the risk factors of overweight/obesity-related lifestyles, particularly those associated with diet, their psychosocial influences and the interactions among these factors. This observational cohort study was carried out according to a standardised protocol and involved a representative sample of the UPV/EHU student population. Anthropometric measurements, direct behavioural determinants, such as physical activity and diet, and indirect determinants, such as social/psychological factors, are considered. In this paper, we present the survey design, instruments, measurements and related quality management. We describe the study sample in terms of its socio-economic and demographic factors and knowledge area and summarise the methodology used to collect the data and obtain the anthropometric measurements. The participants were 603 students (59·5 % female) aged 18-28 years. The crude participation proportion was 53·5 %. Regarding the knowledge area, the lowest response proportions were obtained from the Health Sciences (38·6 %) compared with the Non-Health Sciences (48·3 %) (P = 0·003). The mean age was 20·9 years, and 83·1 % of the sample were from Basque Country. Regarding the socio-economic characteristics, there were significant differences by sex and knowledge area in most studied variables. Moreover, the Health Sciences students were more likely younger, from outside Basque Country, to have parents with university degrees and to have a higher social status. In conclusion, the EHU12/24 cohort provides valuable data for analysing the complexity and multidimensionality of obesity in university students.

The somatotype is a useful method in the analysis of body morphology but no study has identified genetic variants associated with its components. The aim of this study is o replicate the association of 21 SNPs with obesity and to explore their association with the somatotype components, in a sample from the Basque Country (Spain). A case-control study was performed in 472 adults from 18 to 79 years old. A literature search was conducted in PubMed to select genetic variants associated with obesity in European derived populations. After the quality control of the chosen variants, 21 SNPs were finally used to conduct association analyses. Logistic and linear regressions implemented in PLINK (v1.07) were used to assess the association between SNPs and the somatotype. Two genetic variants (rs925946 in BDNF and rs10146997 in NRXN3) showed a significant association with endomorphy ( p < 0.01) while rs10146997 (in NRXN3) and rs9939609 (in FTO) were associated with mesomorphy ( p < 0.01). rs925946 (in BDNF), rs10146997 (in NRXN3), rs9939609 (in FTO) and rs4776970 (in MAP2K5) were associated with ectomorphy ( p < 0.05). In conclusion, four genetic variants (in or near BDNF, NRXN3, MAP2K5 and FTO) contribute to body shape and composition in the analysed sample.

We examined tau haplotype frequencies in two different ethnical groups from the Basque Country (BC): Roma people and residents of European ancestry (general population). In addition, we analyzed the spatial distribution of tau haplotypes in Eurasian populations to explore the genetic affinities of the Romani groups living in Europe in a broader scope. The 17q21.31 genomic region was characterized through the genotyping of two diagnostic single nucleotide polymorphisms, SNPs (rs10514879 and rs199451), which allow the identification of H1 and H2 haplotypes. A significant heterozygous deficit was detected in the Romani for rs10514879. The H2 haplotype frequency proved to be more than twice in the BC general population (0.283) than in the Roma people (0.127). In contrast, H2 frequency proved to be very similar between Basque and Hungarian Romani, and similar to the H2 frequencies found in northwestern India and Pakistan as well. Several statistical analyses unveiled genetic structuring for the MAPT diversity, mirrored in a significant association between geography and genetic distances, with an upward trend of H2 haplotype frequencies from Asia to Europe. Yet, Roma samples did not fit into this general spatial patterning because of their discrepancy between geographical position and H2 frequency. Despite the long spatial coexistence in the Basque region between the residents of European ancestry and the Roma, the latter have preserved their Asian genetic ancestry. Bearing in mind the lack of geographical barriers between both ethnical groups, these findings support the notion that sociocultural mores might promote assortative matings in human populations.

Objective: Specific bioelectrical impedance vector analysis (spBIVA) is a recently proposed technique for the analysis of body composition. The aim of this study was to apply spBIVA to a sample of Italian and Spanish young adults and to define the new bioelectrical references for this Western Mediterranean population., Methods: A sample of 440 individuals (220 from Italy, 220 from Spain; 213 men, 227 women) aged 18-30 years was considered. Anthropometric (height, weight, relaxed upper arm, waist, and calf girths) and bioelectrical (resistance, reactance; 50 kHz, 800 μA) measurements were taken. In order to verify the need for new references, specific bioelectrical values were compared to the reference values for U.S. adults and Italian elderly by tolerance ellipses and Student's t test., Results: The mean specific bioelectrical values (resistivity, Rsp, and reactivity, Xcsp, Ohm·cm) were: Rsp (332.7 ± 41.7 Ω·cm), Xcsp (44.4 ± 6.8 Ω·cm), Zsp (335.6 ± 41.9 Ω·cm) and phase (7.6 ± 0.8°) in men; Rsp (388.6 ± 60 Ω·cm), Xcsp (43.7 ± 7.5 Ω·cm), Zsp (391.0 ± 60.3 Ω·cm) and phase (6.4 ± 0.7°) in women. Italo-Spanish bioelectrical vectors were mainly distributed (>90%) in the lower part of the tolerance ellipses for U.S. young adults, due to a shorter impedance (P < 0.001), indicative of a lower percent fat mass. Compared to Italian elders, they were mainly located in the left side (>90%), due to a higher phase (P < 0.001), indicative of higher body cell mass., Conclusions: These population and age-related differences indicate the need for new specific tolerance ellipses that can be used as references for assessing body composition in young adults from Western Mediterranean populations., (© 2015 Wiley Periodicals, Inc.)

Objectives: 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., Methods: A total of 24 representative single nucleotide polymorphisms (SNPs) were genotyped in 372 individuals belonging to 50 extended families of Roma population. SNPs were tested for association with seven quantitative obesity-related phenotypes in the PLINK program., Results: Risk variants in NEGR1, FAIM2, FTO, and SH2B1 genes were associated with increased adiposity accumulation in Roma population with effect sizes between 0.21 and 0.34 Z-scores for each copy of the BMI increasing allele. Additionally, variants in BDNF and MC4R were significantly associated with adiposity distribution but not with overall fatness. No significant association was detected between obesity-related phenotypes and variants in the first intron of the FTO gene (e.g., rs9939609)., Conclusions: The results of this study suggest that SNPs in or near six genes (BDNF, FAIM2, FTO, MC4R, NEGR1, and SH2B1) are significantly associated with body fat accumulation and distribution in Roma people. However, the association observed among variants in the first intron of FTO and obesity in European derived populations is not evident in the analyzed Roma sample., (© 2014 Wiley Periodicals, Inc.)

Background: Roma people are particularly vulnerable to developing overweight and obesity. Self-perception of body image may influence the prevalence of obesity in this ethnic minority., Aim: The objectives of this study are to estimate the prevalence of obesity, to analyse body size perceptions and preferences and to assess the relationship between body size perceptions and obesity in the Roma population., Subjects and Methods: The analyses were carried out on 372 men, women and children from the Roma population residing in the Greater Bilbao region (Basque Country, Spain). In adults, a standard figural scale was used to analyse body size perceptions and preferences in this ethnic minority., Results: Overall 51.7% of adult and 24.4% of minor Roma individuals were obese. Both Roma men and women had inaccurate self-perceptions of their body size. Significant differences on body size perceptions were detected based on age, sex, nutritional status and socioeconomic characteristics., Conclusion: This Roma population presents one of the highest rates of obesity worldwide. Although a certain awareness of the correct weight status was appreciated, the inability of Roma individuals to see themselves as overweight or obese may be a significant factor on the high prevalence of obesity in this population.

Longitudinal as well as cross-sectional studies have shown variations with age in heritability estimates for body dimensions from infancy to adulthood, even though the patterns of variation are not completely clear. Further study on this subject is of great interest and may help obesity interventions for preventing or treating obesity in children. Therefore, the aim of the present study is to analyse the changes in the genetic and environmental architecture of 8 body linearity and obesity-related phenotypes during the growth process in a cross-sectional sample of 1018 nuclear families from the province of Biscay (Basque Country, Spain). The contribution of additive genetic effects to the variation of the analysed traits was estimated by a variance component analysis using the SOLAR program. Moderate to high heritability estimates were obtained for all 8 anthropometric phenotypes (38.23-65.98%). The heritability values show an increasing trend with age and in the course of the entire ontogenetic development two age periods were remarkable. At 7(+)-8(+) years of age a strong increase in heritability estimates was found for all the anthropometric phenotypes, except for the sum of skinfolds (SF6), reflecting the biological significance of genes during mid-childhood. During puberty, most of the obesity related phenotypes showed their highest heritability values while linear measurements and weight presented a decrease in the genetic contributions. In conclusion, this study confirms that additive genetic influences have a considerable effect on body linearity and obesity-related traits throughout the growth period and that mid-childhood and puberty are very sensitive periods in human life cycle., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Background: The Roma people are particularly vulnerable to developing obesity and related diseases, due to their social and ethnic backgrounds. However, little is known about the genetic and/or environmental factors affecting the variability of obesity-related traits among the Roma population., Aim: The aim of the present study was to estimate heritabilities and common genetic and environmental influences of obesity-related phenotypes in a sample of Roma people living in the Greater Bilbao region (Basque Country; Spain)., Subjects and Methods: Three hundred and seventy-two individuals from 50 large, extended and highly consanguineous pedigrees were phenotyped for anthropometric traits related to obesity. Heritability estimates were assessed for all quantitative traits and bivariate analyses were conducted to assess the phenotypic, genetic and environmental correlations among these traits., Results: Significant heritable components (p<0.01) ranging from 0.25-0.68 exist for the studied phenotypes. Heritability for WHR (h(2) =0.60) considerably surpasses the usual heritability estimates on family-based studies ( <0.30). Measures of overall fatness (BMI, CF and SF) show stronger correlations with each other than body fat distribution traits (WHR, CI and TER)., Conclusions: The study concluded that the Greater Bilbao Roma population is genetically predisposed to abdominal fat distribution. Variation in body mass is highly associated with variation in adiposity. However, overall fatness and adiposity distribution does not seem to share major common genetic factors, although common environmental factors operate between them.

Obesity has become a public-health and policy problem in many parts of the world. Epidemiological and population studies in this field are usually based on different anthropometric measures; however, common genetic and environmental factors between these phenotypes have been scarcely studied. The objective of this article is to assess the strength of these factors on the covariation among a large set of obesity-related traits. The subject group consisted of 533 nuclear families living in the Greater Bilbao (Spain), and included 1,702 individuals aged 2-61 years. Detailed anthropometric measurements (stature, breadths, circumferences and skinfolds) were carried out in each subject. Bivariate quantitative genetic analyses were performed using a variance-components procedure implemented in the software SOLAR. The results revealed that the majority of these traits is affected by common genetic and environmental factors. All correlations were significantly different from 1 and varied from non-significant to very high (>0.90, P < 0.0001), with clearly lower pleiotropic effects among pairs including fat-distribution traits. Despite the strong common genetic effects detected among phenotypes determining the amount of body fat and mass, there is a residual genetic influence on the local fatness measures that cannot be explained exclusively by the genetic influence on overall fatness. Moreover, the observed relationships confirm a partially different genetic control of truncal and peripheral fat. In conclusion, our findings highlight the relevance of considering different types of traits in the prevention and treatment of obesity, as well as in the search for genes involved in its development.

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 (h(2)) 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 h(2) 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 h(2), 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.

Objectives: Several obesity phenotypes (e.g. body mass and fat, fat distribution) have been suggested to be a risk for elevated blood pressure. This study was undertaken to determine the heritability of four blood pressure phenotypes: SBP, DBP, pulse pressure (PP) and mean arterial pressure (MAP) and to assess the strength of genetic and environmental correlations among these phenotypes, and also between blood pressure and the different obesity-related traits., Methods: The studied sample consisted of 429 nuclear families living in the Greater Bilbao (Spain) and included 1302 individuals aged 4-61 years. Univariate and bivariate quantitative genetic analyses were performed using a variance components procedure implemented in Sequential Oligogenic Linkage Analysis Routines software., Results: SBP, DBP, PP and MAP were significantly influenced by genetic factors with heritability estimates of 0.25, 0.28, 0.14 and 0.31, respectively, and presented high genetic and environmental correlations between them (except DBP-PP). On the contrary, whereas SBP, DBP and MAP showed common environmental factors with almost all body mass and fat-related traits, pleiotropic effects were only detected for some pairs, especially for those phenotypes that included skinfolds. In contrast, PP did not exhibit common genetic or environmental factors with obesity phenotypes in the studied population, Conclusion: Blood pressure and obesity phenotypes do not share, in general, a substantial influence of common genetic and environmental effects. Finally, the results obtained revealed the importance of the amount of adipose tissue in the genetic correlations with SBP, DBP and MAP, at least, during the growth period.

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/height(2) (kg/m(2)) 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.

The anthropometric somatotype is a quantitative description of body shape and composition. Familial studies indicate the existence of a familial resemblance for this phenotype and they suggest a substantial action by genetic factors on this aggregation. The aim of this study is to examine the degree of familial resemblance of the somatotype components and of a factor of shape, in a sample of Biscay nuclear families (Basque Country, Spain). One thousand three hundred and thirty nuclear families were analysed. The anthropometric somatotype components [Carter, J.E.L., Heath, B.H., 1990. Somatotyping. Development and applications. Cambridge University Press, Cambridge, p. 503] were computed. Each component was fitted for the other two through a stepwise multiple regression, and also fitted through the LMS method [Cole, T., 1988. Fitting smoothed centile curves to reference data. J. Roy. Stat. Soc. 151, 385-418] in order to eliminate the age, sex and generation effects. The three raw components were introduced in a PCA from which a shape factor (PC1) was extracted for each generation. The correlations analysis was performed with the SEGPATH package [Province, M.A., Rao, D.C., 1995. General purpose model and computer programme for combined segregation and path analysis (SEGPATH): automatically creating computer from symbolic language model specifications. Genet. Epidemiol. 12, 203-219]. A general model of transmission and nine reduced models were tested. Maximal heritability was estimated with the formula of [Rice, T., Warwick, D.E., Gagnon, J., Bouchard, C., Leon, A.S., Skinner, J.S., Wilmore, J.H., Rao, D.C., 1997. Familial resemblance for body composition measures: the HERITAGE family study. Obes. Res. 5, 557-562]. The correlations were higher between offspring than in parents and offspring and a significant resemblance between mating partners existed. Maximum heritabilities were 55%, 52% and 46% for endomorphy, mesomorphy and ectomorphy, respectively, and 52% for PC1. In conclusion, the somatotype presents a moderate degree of familial aggregation. For the somatotype components, as well as for PC1, the degree of familial resemblance depends on age. The sex only has a significant effect on ectomorphy.

The aim of this paper is to verify the existence of dispersion (or variability) dimorphism in several anthropometric traits, i.e., some skeletal, muscular, and adipose dimensions, and to provide an evaluation of this scarcely considered aspect of sex differences. This research focuses on two human samples from two different European regions, Sardinia (Italy) and the Basque Country (Spain). Twenty-three anthropometric measurements were taken. A first qualitative analysis was carried out comparing the profiles of the coefficients of variation of each variable in both sexes. Secondly, the equality of variability was verified with different tests. In the normal case, Student's t-test, as proposed by Sokal and Braumann ([1980] Syst. Zool. 29:50-63), was applied. In the more general case, it was necessary to resort to resampling techniques. A suitable bootstrap test was constructed and the results were compared, when possible, with those obtained by other methods. The measurements showed parallel trends in the two populations. In particular, subcutaneous skinfolds showed significant dispersion dimorphism, with the greatest coefficients of variation in men. We suggest that this result was linked to stronger canalization in female dimensions related to the reproductive function and influenced by sociocultural factors. We also suggest defining dispersion dimorphism, whose existence is confirmed by the results presented in this paper, as a descriptive pattern of phenotype variability in both sexes that can be specific of a given class of anthropometric traits., ((c) 2004 Wiley-Liss, Inc)

This study examined 28 anthropometrical and physiological traits in 107 married couples living in the province of Biscay (Basque Country, Spain). The aim was to verify the existence of a phenotypic and/or social preference when choosing a mate. For this, correlations between pairs of spouses were estimated by maximum likelihood, and a model of familial transmission (path analysis) was applied in order to test if social homogamy between mates existed. The results provide significant evidence of phenotypic as well as social homogamy in several of the studied traits. Even if an assortment existed when choosing a mate for bony traits such as height, the effect of cohabitation cannot be discounted as the main causal factor for the high phenotypic resemblance observed between spouses for body composition traits. In addition, with the social homogeneity of the studied sample, significant evidence of the existence of social homogamy between mates was only found for 20% of the studied variables.

The present research analyses a cross-sectional sample of 284 individuals (86 fathers, 86 mothers, 54 sons and 58 daughters) in 86 nuclear families living in the province of Biscay (Basque Country, Spain), with the aim of estimating both transmissible and non-transmissible components acting on familial resemblance for the maximum dynamometric strength of both hands, by means of a path analysis. Standardised data of each generation and sex were adjusted to a BETA model of path analysis independent of sex effects, allowing nevertheless the possibility to differentiate between transmissible (genetic and cultural) and non-transmissible (environmental) components acting on the observed phenotypic variance in Biscayan offspring. The results supported the full model of familial transmission for the two variables, in addition to other reduced models that gave rise to transmission effects regardless of any influence from the siblings' shared environment on the environmental transmitted component from their parents (b = 0), and without social homogamy between mates (u = 0). The most parsimonious model created, based on the previous ones, was accepted for both traits. The total transmissible variance (t2) explained between 21% (right hand) and 44% (left hand) of the observed phenotypic variation. These values are close to those from the literature (t2 = 37%). However, we should take into account that these kinds of estimations are specific for each group or population.

Anthropometry, records of food intake, and bioelectric impedance were gathered from a sample of 297 adults of both sexes who lived in marginal districts in the town of Bilbao and benefited from a program of social assistance. This survey aimed to determine present nutritional status and to ascertain the relationship between food intake and nutritional conditions. A comparative evaluation of anthropometry and food intake was then carried out using a reference from the Basque Country and a control sample from the same area but from better-off nutritional and socioeconomic conditions. Males from low socioeconomic status (SES) displayed lower heights and weights compared to the local reference and control sample. They showed higher skinfold thickness than males in the local reference but lower thicknesses than those in the control sample. All anthropometric variables, except height, were higher in women of low socioeconomic status compared to the local reference and control sample. Low socioeconomic males had lower estimated percentage of body fat than the control sample, while females showed the opposite pattern. On the other hand, estimates of food intake in males did not reveal great differences among samples from different socioeconomic backgrounds, while low SES females had greater intakes of food than the better-off control sample. Estimated zinc intake showed differences by SES in both sexes.

A cross-sectional sample from Biscay province (Basque Country, Spain) composed of 296 subjects from 143 nuclear families was analysed. The aim of this research was to study familial resemblance for the age at menarche and to investigate the influence that BMI, fatness and several socio-familial variables have on the menarcheal age. The influence of these variables on the degree of similarity of mother-daughter and sister-sister pairs for the age at onset of menstruation will be determined. Mean ages at menarche of mothers estimated by retrospective methodology (12.88 years, SD = 1.57) and daughters assessed by probit analysis (12.34 years. SD= 1.00) showed no statistically significant differences. Mother-daughter and sister-sister correlations increased after controlling for BMI, fatness and several socio-familial variables (0.25 vs 0.36 and 0.28 vs 0.44, respectively). The results revealed the importance of BMI, fatness, socio-economic level and the number of people living together in the household on menarcheal age and on the estimation of correlations. However, no influence from sibship size (possibly because this variable is a part of the people living together in the household) nor from birth order of the subjects was observed.

The present study is focused on the analysis of skin color correlations in a sample of 1039 siblings aged 4 to 20 years from the province of Biscay (Basque Country, Spain). Measurements were taken at the upper inner arm and forehead by means of an EEL DS29 Digital Unigalvo reflectance spectrophotometer fitted with filters 601, 605, and 609. The reflectance data were internally standardized according to sex and age of the individuals, and the analysis of the degree of similarity between siblings was based on the calculation of intraclass correlation coefficients. All 3 filters gave fairly high and statistically significant correlations regarding forehead skin color (between 0.28 and 0.45) for all types of siblings under consideration. However, with respect to filter 609 the arm reflectance values did not reveal correlation either between brothers (0.01) or between siblings (0.02), even though it did reveal correlation between sisters (0.29). When other filters or type of sibling were considered (also for arm), all coefficients happened to be statistically significant and relatively high (0.35-0.43). This study confirms that the degree of sibling resemblance with regard to skin pigmentation is influenced by growth factors and that the upper inner arm and the forehead skin patterns change with age in the sense that, during and especially after puberty, the coefficients of correlation are higher for arm reflectance than for forehead reflectance; the forehead is a site that is more influenced by environment.

Following the anthropometric method of Heath-Carter (1967) individual somatotypes of a sample of 1260 school children (605 boys and 655 girls) living in Bilbao and aged between 14-19 years have been investigated. Age differences of the somatotype components and sexual dimorphism of the physique were also analyzed. In both sexes, somatotype varies with age. The main factor for these variations of the somatotype is in the boys the endomorphy, and in the girls the mesomorphy. The mean somatotypes of the total sample are in boys central (3.9-3.9-2.7) and in girls mesomorphic-endomorphic (5.3-3.1-2.3).

Reported data on age at menarche in a sample of Biscayan schoolgirls are compared with data from several Spanish populations. Though the mean age falls in the range of variation of the Spanish means, the analysis of variance shows significant differences among the series. With regard to the possible secular trend of this event in the Biscay province, both a stability of menarcheal age and a diminution of the process of variability are observed.

Skin colour variation with increasing age was analysed using a cross-sectional sample of 796 Basque boys aged from 8 to 19 years. Measurements were taken at the upper inner arm and forehead by means of an EEL DS29 Digital Unigalvo reflectance spectrophotometer with a nine-filter head. Ontogenic changes of skin pigmentation were found to be statistically significant. The influence of the month in which measurements were taken on reflectance values has been studied. Comparisons with another similar study (Pembrokeshire, Wales population) were carried out.

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.

Secretion of the ABH blood group antigen was analyzed in 305 saliva samples of students in the Basque Country University. The frequency of ABH non-secretor was 26.23%, a result very close to that obtained in autoctonous Basques (22-23%) and in other populations from the West (Galicia) and Centre (Castille) of Spain. With certain exceptions, the frequencies of non-secretor se allele present a fairly homogeneous variability pattern and no significant spatial orientation or tendencies of se gene distribution are observed in the Iberian Peninsula.

The incidence of red-green colour vision defects was studied in a sample of 392 Basque students (174 males and 218 females), using the Ishihara test cards (1987). The frequency of red-green colour blindness was 4.02 percent in the males and 0.46 percent in the females. The colour blindness frequencies found among males are within the range of other Spanish samples. Nevertheless they are lower than the values reported in other European populations.

Skin colour has been analysed in 352 males and 393 females of the Basques. Measurements of upper-arm reflectance were taken using 9 filters of an EEL reflectance spectrophotometer. Regional differences are not found. Sexual dimorphism is not equally revealed in all filters in the same manner, but females are, on average, lighter skinned than males. By means of Penrose's size ans shape distance comparisons were made with several European populations.