Endocrine Abstracts

Background: Hypothyroidism has been linked with an increased risk of morbidity such as cardiovascular disease and diabetes mellitus. However, it is unknown whether the burden of morbidity is present before or after the diagnosis of hypothyroidism.

Aim: Evaluate the temporality and type of morbidity in hypothyroid patients.

Methods: Observational cohort study. Based on record-linking between official Danish health registers 2822 subjects with hypothyroidism were identified and matched with four non-hypothyroid controls and followed over a mean period of 6 years. Prevalence of cardiovascular diseases (CVD), lung diseases, diabetes mellitus (DM), rheumatic diseases (RHD) and malignant diseases were recorded. Logistic and cox regression models were used to assess the risk of morbidity before and after the diagnosis of hyperthyroidism, respectively.

Results: In subjects with hypothyroidism, the odds ratio (OR) was significantly increased for CVD (OR 1.37; 95% CI: 1.19–1.58), lung diseases (OR 1.25; 95% CI: 1.13–1.39), DM (OR 1.92; 95% CI: 1.61–2.29) as well as malignant diseases (OR 1.24; 95% CI: 1.06–1.45), prior to the diagnosis of hypothyroidism. The hazard ratio (HR) for disease after the diagnosis of hypothyroidism was significantly increased for CVD (HR 1.36; 95% CI: 1.15–1.60); lung diseases (HR 1.51; 95% CI: 1.30–1.75); and DM (HR 1.40; 95% CI: 1.11–1.77).

Conclusions: Prior to the diagnosis of hypothyroidism there is an increased risk of being diagnosed with CVD, lung diseases, DM, and malignant diseases. Following the diagnosis of hypothyroidism there is an increased frequency of CVD, lung diseases, and DM.