Effect of plasma carboxyhemoglobin level on gonadal hormone levels.

Background: In emergency departments, carbon monoxide (CO) is a common cause of toxic poisoning. We aimed to determine the relationship between plasma carboxyhemoglobin (COHb) levels and late post-treatment gonadal hormone changes in CO poisoning.

Methods: The study included 237 patients older than 18 who presented to the Emergency Department due to CO intoxication between January 2008 and December 2016. Patients with a COHb level of less than 30% were classified as having mild-to-moderate disease, while those with a COHb level of more than 30% were classified as having severe disease.

Results: Of 41 (17%) patients with gonadal hormone change (GHC), 19 (46.3%) were females. In cases with GHC, the exposure time was 5.76±1.64 hours (P=0.001). COHb level was 50.46±4.43% in the severe group (P=0.001), while hormone levels were normal in women and men before CO poisoning. GHC within one month and two years after poisoning was significantly higher (P=0.001). There were 138 (58.2%) patients in the mild-to-moderate group, and 99 (41.8%) patients in the severe group. Of the gonadal hormones, LH2 (luteinizing hormone) was 13.54±3.40 mIU/mL, FSH2 (follicle-stimulating hormone) 16.69±4.35 mIU/mL, PRL2 (prolactin) 16.23±4.73 ng/mL, and TTN2 (testosterone) 644.06±120.40 (P=0.001). In addition, COHb was found to be 42.68±8.42% (P=0.001). In univariate and multivariate Cox regression analysis, gender, LH1, LH2, PRL2, TTN2 and COHb values were found to be prognostic signs in terms of endocrine gonadal hormone change (P<0.05). In the correlation of COHb level with GHC, positive moderate-strong correlation was found between LH2, FSH2, PRL2, TTN2 (P=0.001).

Conclusions: In patients admitted to the emergency services due to CO poisoning, elevated COHb may help predict the risk for late gonadal hormone levels.