Gender- and age-related differences of hair calcium, potassium, magnesium, sodium, and phosphorus levels in children with autism spectrum disorder and speech development delay

The aim of the study was to assess the level of macro elements in children with autism spectrum disorder (ASD) and speech development delay (SDD) using hair samples in order to identify age, gender, and nosological differences between the groups. The study included 1,117 children, in particular: 258 children with ASD, 239 children with SDD, and 620 healthy children as a control group. All children were divided into two age categories - from 1.5 to 3 years old and from 4 to 13 years old. For boys and girls with ASD and SDD up to 3 years a significant decrease in hair level of potassium (by 42 - 51%, p < 0.02 for boys and by 54%, p < 0.02 for girls) and sodium (by 22 - 23%, p < 0.01 for boys and 38 - 42%, p < 0.05 for girls) compared to the control group was found. This difference was not observed in the older age group. Hair magnesium level also was significantly reduced in both boys and girls with ASD and SDD (by 8 - 17%, p < 0.02 in boys and by 23 - 32%, p < 0.001 in girls). Girls with ASD of all ages demonstrated significant decrease in hair calcium level (by 14 - 27%, p < 0.01). Significant decrease of this element was also found in older boys with SDD (by 14%, p = 0.02) compared to control. The content of phosphorus in hair samples was significantly reduced in younger boys and girls with ASD (by 7%, p = 0.01 and 11%, p = 0.01, respectively). The level of macro elements was found to be most impaired in the youngest age group with ASD and SDD. The balance tended to return to normal with age. Moreover, the degree of macro element impairment was highest within the ASD group of girls. The data obtained indicates gender, age, and nosological differences in macro elements hair content in children with ASD and SDD.