The coast of giants: An anthropometric survey of high schoolers on the Adriatic coast of Croatia

[Jana]

Link to full paper:https://peerj.com/preprints/3388/

The aim of this anthropometric survey was to map regional differences in height and body proportions in eight counties adjacent to the Adriatic coast of Croatia. Body height was measured in 1803 males and 782 females aged 17-20 years at 66 schools in 23 towns. When corrected for population size, average male height in the eight counties is 182.6 cm (182.8 cm in seven counties of Adriatic Croatia and 183.7 cm in four counties of Dalmatia proper). Regional variation is considerable (3.5 cm): from 180.6 cm in the county of Karlovac to 184.1 cm in the county of Split-Dalmacija. The height of females in the eight counties is 168.2 cm (168.3 cm in Adriatic Croatia and 168.5 cm in Dalmatia proper), but it is based on more limited data. The results show that young men from Dalmatia are currently the tallest in the world in the age category of 18 years, and the north-to-south gradient of increasing stature on the Adriatic coast largely mirrors that in Bosnia and Herzegovina (BiH). These parallel changes of height in Croatia and BiH can most likely be explained by unique genetic predispositions that are shared by the local populations of the Dinaric Alps.

[Jana]

Our previous study dealing with the stature of young males in Bosnia and Herzegovina (BiH) (Grasgruber et al., 2017) confirmed older reports according to which the people from the Dinaric Alps are one of the tallest in the world. It is obvious that they cannot currently reach their genetic potential due to poverty and a relatively poor quality of their diet, but given the presence of these factors, their height is even more remarkable. The height of young men from Herzegovina aged 17-20 years is 183.4 cm, which is only a slightly lower value than in the wealthy and well-fed Dutch (183.8 cm), who are officially the tallest in the world (Schönbeck et al., 2012). Furthermore, our comparisons indicate that local Muslim (Bosniak) men in Herzegovina are 2-3 cm shorter than Croats and Serbs living in the same regions or even the same towns. These differences in height are very strongly associated with the regional production of pork. Because pork is absent in the diet of Muslims for religious reasons, this result independently confirms the key role of high-quality nutrients from pork in child nutrition, as can be seen from our previous ecological studies (Grasgruber et al., 2014; Grasgruber et al., 2016). The study of Pineau et al. (2005) performed between 2001-2003 showed that areas with extraordinary height are not limited to Herzegovina and have an analogy on the Adriatic coast in Dalmatia. This study covered the region of Split and Šibenik, Drniš, Sinj, Imotski, Vrgorac and Dubrovnik, but not northern Dalmatia (counties of Zadar and Lika-Senj) and the northern Adriatic coast of Croatia. The authors reported a mean height of 183.8 cm (n = 1253) in local males aged 17 years (J.-C. Pineau – pers. communication, 2013). The averages of high schools in individual towns ranged from 183.1 cm in Dubrovnik (n=259) through 184.5 cm in Split (n=875) to 187.0 cm in Drniš (n=21). These values are similar to those that we documented in Herzegovina. However, the pooled average of 18-to-19-year old boys in the Croatian capital of Zagreb was only 180.1 cm in 2010 (n=133) (Petranović et al., 2014). In a nationwide study performed between 2006-2008, the average height of Croatian boys aged 18 years was 180.5 cm (n=358)(Jureša et al., 2012). These data strongly suggest that the Dalmatian phenomenon is only a regional anomaly and height decreases rapidly in the northern direction towards mainland Croatia. Indeed, historical data show that the average Croatian recruit around 1883 was 165.5 cm tall (Komlos, 2007), but height on the Adriatic coast ranged from 166 cm in Istria to 171 cm in southernmost Dalmatia (Coon, 1939).

[Jana]

lthough Dalmatia has a very pleasant Mediterranean climate, it has suffered from severe deforestation since the Neolithic (Kranjc, 2009), which led to the creation of an unhospitable ‘limestone desert’ covered by grass and bush. The local population has historically relied on pastoralism and at present, the inland Dalmatia is characterized by high rates of emigration for economic reasons. Furthermore, during the war events 1991-1995, ethnic tensions in the counties of Šibenik-Knin, Zadar, Lika-Senj and Karlovac led to the displacement of the local Serbian population. After the end of the war, the areas experienced an influx of Croatian (Catholic) refugees from BiH. Because of these ongoing population changes, our research is one of the last opportunities to capture the original distribution of anthropological characteristics in this region. We were particularly interested in whether the north-to-south height gradient follows that documented in BiH – from 180.0 cm in Canton Una-Sana to 184.5 cm in the region of Trebinje. Therefore, we decided to include the whole area of coastal Croatia adjacent to the border of BiH.

[Jana]

o provide detailed mapping of body height and some other anthropological characteristics on the territory of the Dinaric Alps, which would enable better understanding of this intriguing phenomenon. At present, this project already covers Bosnia, Herzegovina, Croatia, Montenegro and Kosovo. In addition, preliminary measurements of university students were performed in Albania during the year 2017. The survey in Montenegro will be repeated in 2018. The present study was realized within the project "Anthropological research of sports potential in Dalmatia", number MUNI/A/1090/2016, with the support of the Specific University Research Grant, as provided by the Ministry of Education, Youth and Sports of theCzech Republic in the year 2016. Its primary objective was to measure body height and some body proportions (sitting height, arm span) on the territory of Adriatic Croatia, as defined by the Croatian Bureau of Statistics (Narodne novine, 2012). This region consists of seven counties (županijas): Istra, Primorje-Gorski Kotar, Lika-Senj, Zadar, Šibenik-Knin, Split-Dalmacija a Dubrovnik-Neretva. Total population in these seven counties is 1.41 million (33% of the total Croatian population) (Croatian Bureau of Statistics, 2013). Because the counties of Primorje-Gorski Kotar and Lika-Senj are largely separated by the mainland county of Karlovac, we also decided to include the latter to have a more complete picture (Fig. 1). The eight counties together comprise 1.54 million people (36% of the total Croatian population). Target population. The target population consisted of high schoolers (3rd and 4th graders) aged 17-20 years. Similar to our previous study in BiH, we always tried to measure the broadest spectrum of schools, from vocational to elite high schools (gimnazija). Our general goal was to incorporate sufficiently representative samples of ≥ 200 individuals from each region. For organizational or time reasons, it was not always possible to measure a sufficiently large sample of both sexes and hence we again concentrated mainly on males. The same limitations infuenced the measurement of body proportions. Data collection. The research was performed between April 2015-May 2017. Very few of the schools contacted refused to participate, which allowed us to meet most of our goals. The measurements were conducted using two devices – a mobile stadiometer SECA 213 and a specially constructed apparatus designed for the measurement of height, sitting height and arm span.

[Jana]

Remarkably, the anomaly in the area of Čapljina (185.9 cm) and Široki Brijeg (185.4 cm), where we found the tallest means in BiH, has an analogy on the Croatian side of the border in the towns of Metković (184.9 cm), Imotski (186.2 cm) and Makarska (187.6 cm) (Table 3). Although all the samples are relatively small (21-38 males), such a high frequency of extremely tall means within a small geographical area cannot be a mere coincidence. This suggests that the peak of male height should be sought in the area demarcated by Makarska –Imotski –Široki Brijeg –Čapljina - Metković.

Average male and female height in 14 individual towns accoding to the self-reported place of residence. Only towns with at least 20 measured individuals are included. In the direction to the north of this area, height begins to decrease quite rapidly, although this change is not always evident at the level of individual towns. The average of the Šibenik-Knin county (183.4 cm) is 0.7 cm lower than in the Split-Dalmacija county, but boys from Šibenik are still very tall (184.2 cm), taller than boys in Split. A similarly high mean was found in the school in Drniš (184.4 cm, n=42), which is situated approx. 35 km far inland. In fact, a small sample of boys resident in Drniš (186.6 cm, n=15) reached almost the same average height as the sample of Pineau et al. mentioned above (187.0 cm). However, two schools in Knin, which is approx. 25 km further inland, were much shorter (182.8 cm, n=39) and a sample of boys resident in Knin reached only 181.7 cm. We cannot exclude the possibility that these large differences between coastal and inland regions are due to relatively small sample sizes, but the same findings were previously reported even by Prebeg (1988) and ascribed to economic factors.



In the direction to the north of this area, height begins to decrease quite rapidly, although this change is not always evident at the level of individual towns. The average of the Šibenik-Knin county (183.4 cm) is 0.7 cm lower than in the Split-Dalmacija county, but boys from Šibenik are still very tall (184.2 cm), taller than boys in Split.

[Jana]

Unlike young men that are tallest in the world in one specific region, Croatian females are quite shorter than that. Female height:

After the correction for population size, the average female height would be 168.5 cm in Dalmatia, 168.3 cm in seven counties of Adriatic Croatia and 168.2 cm in all eight counties. In general, it seems that girls in counties with the tallest boys (around 184 cm) reach a height of approximately 169 cm (Table 4). This is a very tall mean, but not as tall as in the young women aged 20-21 years in the Netherlands (170.5 cm) (Schönbeck et al., 2012) and shorter than the results of Pineau et al.(2005)from Split (171.1 cm, n=873) and Drniš (174.3 cm, n=42). In the present study, we found only one school with a mean height over 170 cm - Gimnazija Imotski (170.5 cm, n=24). The only female sample measured by Pineau et al. which stands close to our results is that from Dubrovnik (169.4 cm, n=259). Relationship between male and female height. The unexpectedly shorter height of girls is accompanied by an unusually large difference in mean height between boys and girls in the eight counties, reaching 15.5 cm in the county of Šibenik-Knin and 14.4 cm on average (when comparing means corrected for population size). Even if we compare samples that are most representative (Istra, Karlovac), the sex difference is still 14.4 and 14.0 cm, respectively. At the same time, the usual difference in Europe is only 13 cm.

The sex differences between men and women in former Yugoslavia appear to be larger than the global trend line predicts.

[Dick]

That's because their mothers would spank them if they didn't finish eating their meat at dinner

[Jana]

The quality of nutrition in Croatia is still deeply suboptimal, which is a situation that has analogies even in other countries of the former Yugoslavia (Bosnia and Herzegovina, Macedonia, Serbia). Only Slovenia (1.56) and Montenegro (1.53) are above the European mean.

[Dick]

You forgot this

[Jana]

Genetics. The genetic aspects of the exceptional stature on the Adriatic coast are certainly the most interesting, but still supported only by a superficial genetic marker – frequencies of Y haplogroup I-M170 in the European context (Fig. 6). This mutation on the male Y chromosome can be linked with the Upper Paleolithic Gravettian culture and after the end of the Ice Age, it expanded from the ‘Epigravettian’ glacial refugium around the Adriatic sea (for a more detailed discussion, see our previous paper Grasgruber et al., 2017). All we can say at the moment is that North European populations carrying high frequencies of I-M170 deed do carry single nucleotide polymorphisms (SNPs) associated with tall stature(Robinson et al., 2015).



Remarkably, regional data on I-M170 frequencies from Herzegovina, Bosnia, the Zadar county in Dalmatia and Dubrovnik (Peričić et al., 2005; Šarac et al., 2016) fit the relationship between height and I-M170 at the country level, although height is still lower than expected, especially in the case of the Zadar county. This can be explained by the very small size of the Zadar genetic sample (n=25). Only Kosovo is a clear exception, apparently due to the strong recent drift of Y haplogroup E1b-M78 in the local Albanians (Peričić et al., 2015).