Gene polymorphism and serum levels of insulin-like growth factor-I in Egyptian acne patients

Background Insulin-like growth factor-I (IGF-I) is associated with increased sebum production. The IGF-I [cytosine–adenosine (CA)] polymorphism was found to be significantly associated with acne vulgaris in a Turkish population. Objective The aim of the study was to investigate the IGF-I (CA) polymorphism in a sample of Egyptian acne patients, estimate their IGF-I serum level, and study the relation between the gene polymorphism and serum levels. Patients and methods This case–control study included 50 acne patients and 50 healthy controls. The Global Acne Grading System was used to assess severity. PCR was used to study the IGF-I polymorphic area. The enzyme-linked immunosorbent assay (ELISA) was used to estimate the serum IGF-I level. Results The heterozygous (192–194 bp) genotype was found significantly more in the acne group (P = 0.029), whereas the homozygous (4194 bp) genotype was found significantly more in controls (P= 0.024). There was no significant effect of age or sex on the IGF-I polymorphism, and there was no effect of the polymorphism on the severity of acne. Positive family history was found significantly more among heterozygous carriers (P= 0.013). A significantly higher serum IGF-I level was found in acne patients compared with controls (Po0.0001). Serum IGF-I levels were not affected by sex. Mild cases of acne had significantly higher serum levels (Po0.0001) compared with moderate and severe cases. Homozygous carriers (o192 bp and 194 bp) showed significantly higher levels compared with heterozygous carriers with the highest level in the homozygous (4194 bp) group (Po0.0001). Conclusion It appears that the IGF-I (CA) polymorphism may contribute to a predisposition to acne. Serum IGF-I level is significantly higher in acne patients than in controls; however, it seems to be influenced by several factors other than the IGF-I (CA) gene polymorphism.