Menarcheal age of Turkish girls in Bremen

Several studies have shown that there is a Northwest-Southeast gradient in menarcheal age of European girls, with menarche occurring on the average about one year earlier in girls living in the Southern parts of Europe as compared with those from the Northern and Northwestern European countries. Eveleth & Tanner (1976) as well as Danker-Hopfe (1986a) suggested that this gradient is due primarily to genetic differences rather than climatic or nutritional variation. To substantiate this hypothesis menarcheal age of Turkish girls who lived in Bremen for several years has been investigated. The mean age at menarche estimated by probit analysis based on status quo data from n = 494 girls aged from 9.0 to 16.5 years was 12.90 +/- 1.21 years. These results correspond very well to those reported by Neyzi et al. (1975) for girls from Istanbul. On the other hand mean menarcheal age of Turkish girls living in Bremen is distinctly lower than mean age at menarche of urban German girls, living in the same district. In summary the results of the present study support the hypothesis of a predominantly genetic cause for the observed Northwest-Southeast gradient in age at menarche in Europe.