Are steroid hormones and autistic traits affected by metformin? First insights from a pilot

Background: Different lines of evidence imply that metformin could alter steroid hormone homeostasis and thereby improve social impairment. Here, we tried to correlate the impact of metformin treatment on alterations in steroid hormones and autism spectrum traits before versus after treatment with metformin. Material & methods: Urine steroid hormones were measured using gas chromatography mass spectrometry in 12 male subjects (54.2 +/- 9.1 years, 177.3 +/- 4.1 cm, 80 +/- 10.4 kg) and 7 female subjects (64.14 +/- 18.0 years, 162.7 +/- 4.1 cm, 76.1 +/- 10.4 kg). Furthermore, a questionnaire on autism spectrum traits (Autism Spectrum Questionnaire]) was administered prior to and after metformin treatment. Results: Overall, a decrease of steroid hormones were detected, which were most pronounced in the metabolites of corticosterone, deoxycortisol, cortisol, as well as androgens. These remained after Bonferroni correction (three classes: glucocorticoid, mineralocorticoid, androgens). No effect on autism spectrum traits (social skills, attention switching skills, attention to detail skills, communication skills, imagination skills), was identified pre versus post metformin treatment. Discussion: The decreased steroid hormone levels are based on different mechanisms; one effect is likely via mitochondria, another effect via activated protein kinase prior to post treatment. The finding on autistic traits must be taxed as negative and do not directly provide an argument for using metformin in the treatment of autism.