Objectives

To establish the correlation between hypothyroidism and blood pesticide levels.

Materials and Methods

Cross-sectional study in agricultural workers and their permanent partners in plantain and coffee producing municipalities as reference population. A representative sample was estimated and thyroid function tests were performed using ELISA Stat Fax 303/Plus reader, at a wavelength of 450 nm. Organochlorine pesticide residuality was determined, a dispersive liquid-liquid microextraction (DLLME) assisted by sonication was implemented, and a gas chromatography-micro-electron capture detector (GC-pECD) was used for the analysis.

Results

819 participants, 58.7% men and 41.3% women were included; their average age was 48.1 years. Prevalence of symptomatic hypothyroidism (1.2%) and subclinical hypothyroidism (6.7%) was observed, with a higher prevalence in people older than 60 years (2.6% and 8.9%, respectively). Non-causal association was found between subclinical hypothyroidism and the organochlorine pesticides 4,4'-DDE (sig.0,006), Heptachlor (sig.0,04), and Endosulfan I (sig.0,02). Antiperoxidase (Anti TPO) antibodies ≥60 lU/ml were associated with subclinical hypothyroidism (OR 2.6).

Conclusions

The prevalence of hypothyroidism in the studied population is similar to that reported in the literature, and lower than in urban areas. In turn, the prevalence of subclinical hypothyroidism is higher and positive anti-TPO values are related to risk of progression to frank hypothyroidism, which is why follow-up is required in these patients. Three organochlorine pesticides were associated with subclinical hypothyroidism. TSH screening is recommended in people aged 40 and over, especially if they are exposed to the aforementioned agrochemicals.