Microgeographic differentiation in historical Yemen inferred by morphometric distances.

This study analyzed the variations in space of 8 body dimensions and 11 measures of the head of 1,244 adult Yemenite males, collected in 1933/34 by Coon in Yemen and in Hadhramawt. The aim was to evaluate the presence of geographic microdifferentiation of the populations settled in the different regions of Yemen at the time. Coon sub-divided the sample into six geographical areas according to birthplace and ethnicity of the individuals: Tihamah, the Western Mountains, the Central Plateau, the South Coast, the Eastern Mountains, and Hadhramawt. The results of ANCOVA (age as covariate) show that the observed differences of all variables among the six groups were highly statistically significant. Tukey's post-hoc test reveals higher statistically significant differences among four main groups: (1) Tihamah; (2) the Western Mountains and Central Plateau; (3) the Eastern Mountains; and (4) the Southern Coast and Hadhramawt. Multiple discriminant analysis carried out using only the data of the 11 measures of the head, the more "genetically" determined variables, confirmed these differences. Indeed, the first canonical variate well separates the groups with the Tihamah, Southern Coast and Hadhramawt on the one side and the Eastern Mountains, Western Mountains and Central Plateau on the other. The second canonical variate separates the Tihamah, Western Mountains and Central Plateau from the Eastern Mountains, Southern Coast and Hadhramawt. In conclusion, the Yemenite population seems to be composed of three morphologically distinct groups and an Eastern Mountains group which is positioned between the group formed by the Southern Coast and Hadhramawt and the Western Mountains and Central Plateau group. The Tihamah is the most distant from all the other groups. These differences are probably due to the presence/absence of geographical and cultural barriers that have favored/blocked the gene flow over the years. Indeed, the entire coastal bell, through the centuries, has constituted one of the principal commercial routes between the East, Africa, and the eastern Mediterranean, while the high inland mountains have isolated the remaining communities. This data is also confirmed by genetic studies. Finally, the average height (162.6 cm) of the global Yemenite population, compared to data from the other six middle-eastern Arab countries and Egypt, was found to be 3-6 cm less. This characteristic will be further studied, analyzing variations in average height according to the different age classes in order to evaluate any possible secular changes.

Morphometric distances among five ethnic groups and evaluation of the secular trend in historical Libya.

This study analysed the variations, both in space and time, of 10 body dimensions and 2 anthropometric indexes of 745 adult males belonging to 5 ethnic groups of historical Lybia (el-Haràbi, el-Baraghìts, Marabtìn, Oases inhabitants and Tuareg). The data were collected in the years 1928 and 1932 by Puccioni and Cipriani, two Italian anthropologists. The aim was to reconstruct the biological history of Libya at the time, and thus contribute to the ongoing debate on the evolution of the biological standard of living in developing Countries. The subjects were analysed by ethnicity and by 10-year age groups, after adjusting for age. The results of ANCOVA and Tukey's post-hoc test show that among and between groups there are statistical significant differences overall for armspan, height, head breadth, bizygomatic breadth, biiliac breadth/height and head breadth/head length indexes. By means of the cluster analysis, the el-Haràbi, el-Baraghìts and Marabtìn groups cluster together, whereas the Tuareg and Oases inhabitants cluster separately one from the other and both from the other three ethnic groups. Within-group variations are not very marked in all ethnicities. In general, there is the tendency, not statistically significant, to the reduction and/or stasis of body dimensions from the older to the younger, and the differences are greater among the older than the younger age classes. In conclusion, it can be argued that these groups, all different culturally and geographically, were following the same tendency of stasis of the secular trend of the body dimensions considered in this study, and such stasis persisted since, at least, the last twenty years of the 19th century, when the older were born.

Anthropometric variables of a sample of Italian adults and their relation to physical activity.

The increasing diffusion of fitness centers in Italy is a response to the growing awareness of the serious health risks of a sedentary lifestyle. In the present study, we defined the anthropological profile of members of a sports club in Rieti (Latium, Central Italy) and evaluated the effects of constant physical activity on their somatic characteristics. Data from 335 healthy males and females were used. We analyzed 36 anthropometric measures in two large age classes (20-39 years and 40 years and over). In a subsample of 40 volunteers, the measures were recorded again after about 5 months (on average). Student's t-test showed significant differences (p = 0.05) between the two age classes for 8 variables in the males and 11 variables in the females and highly significant differences (p = 0.001) for 6 variables in the males and 4 in the females. In the subjects measured a second time, the paired t-test showed significant differences for 12 parameters in the males and 7 parameters in the females and highly significant differences for 7 variables in the males and 10 in the females. The differences between the two age classes in both sexes confirm the presence of both the secular trend and significant morphological changes due to aging. The significant decreases of all health-related anthropometric measurements after an average of 5 months of physical activity in both sexes demonstrate that the beneficial effects of regular physical activity become apparent after only a few months.

Comparison of self-reported and measured height and weight: implications for obesity research among young adults.

BACKGROUND: The use of self-reported data in epidemiological surveys leads to misclassification of the prevalence of obesity as the participants overestimate or underestimate height, weight and/or both. Such misclassifications vary according to gender, age, status and ethnicity. OBJECTIVES: To estimate on a sample of youth of both sexes (1) the difference between self-reported data and measured height and weight and (2) the extent of misclassification of BMI deriving from such differences. METHODS: Self-reporting in questionnaires and subsequent measurements of height and weight conducted by trained personnel. The mean values and the BMIs were calculated. RESULTS: Both sexes overestimate height (2.1 and 2.8cm for males and females, respectively), and underestimate weight (1.5 and 1.9kg for males and females, respectively). Consequently the BMI is underestimated (1.1 and 1.5 points for males and females, respectively). The classification of BMI from self-reported data shows underestimation of overweight in both sexes (8 percentage points) and of obese males (3.3 percentage points), an overestimation of normal weight (12.2 and 4.3 percentage points for males and females, respectively) and an excessive underweight in the girls (4.3 percentage points). CONCLUSIONS: There is a difference between self-reported and measured data and self-reported biases are reflected in the classification of the participants in the 4 categories of BMI.