Autism is a complex neurodevelopmental disorder, the pathogenesis of which remains unclear. Recent research suggests a possible role of hormonal abnormalities in the pathogenicity of autism. In this investigation, we measured serum levels of leptin, ghrelin, and growth hormone (GH) in 40 age-matched Bahraini children, 20 with autism (16 males and 4 females) and 20 healthy children (13 males and 7 females). Hormonal levels were measured by enzyme-linked immunosorbent assay method.
Leptin levels were found to be significantly higher in children with autism (78.05 ± 17.99) than in healthy control children (19.96 ± 11.20), (P = 0.038). Conversely, ghrelin levels were lower in children with autism (62.40 ± 16.98) than in controls (91.50 ± 36.30), however, without reaching statistical significance (P = 0.32). Similarly, GH levels were lower in children with autism (0.63 ± 0.02) than in controls (0.72 ± 0.09), but didn't reach statistical significance (P = 0.33). Regression analysis confirmed a direct association between higher leptin levels and autism (OR: 0.896, 95% CI: 0.816-0.984, P = 0.021), and this association remained significant after adjustment for age, sex and body mass index (OR: 0.800, 95% CI: 0.669-0.956, P = 0.014).
The significantly higher levels of leptin in autistic children may suggest an important role of this hormone in the pathophysiology of autism. While the levels of ghrelin and GH seemed to be low in autistic children, both were not significantly different than in controls. This study is particularly important to improve translation from medical research to health policy in Bahrain, and further validation studies with a larger sample size are required to clarify the relation of these hormones with autism.