Geographic latitude and prevalence of adolescent idiopathic scoliosis

Adolescent Idiopathic Scoliosis (AIS) prevalence has been reported to be different in various geographic latitudes and demonstrates higher values in northern countries. A study on epidemiological reports from the literature was conducted to record the prevalence of AIS among the general population of boys and girls, aged 10-16 years old, in different geographic latitudes, in order to test the hypothesis that the prevalence of AIS among boys and girls is different in various geographic latitudes and to examine if there is a possible association between them. Seventeen peer-reviewed published papers reporting AIS prevalence in the general population of boys and girls from most geographic areas of the northern hemisphere were retrieved from the literature. The geographic latitude of each centre where a particular study was originated was documented. The statistical analysis included a linear regression forward modeling procedure of the AIS prevalence by latitude, weighted by sample size. According to the modelling of the data, a significant positive association between prevalence of AIS and latitude was found for girls (p<0.001), following a rather curvilinear trend, but not a significant positive association was found for boys (p<0.111). A positive association between prevalence of AIS and geographic latitude is reported only for girls in the present study. Prevalence of AIS in boys is not associated significantly with geographic latitude. This differing significant association implicates the possible role of environmental factors in the pathogenesis of AIS that may act in a different way between boys and girls.