Chronic glue sniffing with transient central hypothyroidism and hypergonadotropism

Neuropsychiatric, gastrointestinal and muscular disorders associated with glue sniffing have been widely reported, but endocrinologic abnormalities of glue exposure are rarely mentioned in the literature. We report a 26-year old male patient, a chronic glue sniffer, who presented with weakness of both lower limbs. On physical examination, he had reduced muscle strength of his 4 limbs, especially in his lower limbs. Laboratory examination revealed hypokalemia with hyperchloremic metabolic acidosis. His thyroid function showed low TSH, T4, T3, free T4 and reverse T3 level. Other pituitary functions were normal apart from high FSH and LH level. TSH response to TRH stimulation was normal, but there was impaired T3 response to TRH. MRI of pituitary showed no significant changes. He continued glue sniffing after discharge. He repeatedly came to our hospital for recurrent hypokalemic paralysis. His serum T4 and free T4 level were low when he had certain amount of glue sniffing and it returned to normal after he stopped sniffing or sniffed less amount of glue. His serum T3 concentrations were normal most of the times thereafter. His FSH and LH level were persistently elevated, even after he did not sniff glue for 2 weeks. Low free T4, TSH and reverse T3 level associated with glue sniffing in our patient were compatible with central hypothyroidism. Toluene, a neurotoxic organic solvent, is present in glues. Being highly lipophilic, it can easily enter and is retained within the lipid-rich nervous system after being inhaled. Like other organic solvents, toluene has been shown to affect dopaminergic and adrenergic turnover within various parts of the brain. The effects on these neurotransmitters could lead to abnormal secretion of pituitary hormones resulting in transient central hypothyroidism and abnormal gonadotropin levels. Long-term harmful effect of central hypothyroidism and chronic influence of abnormal gonadotropins to reproduction function needs further observation.