Burden, Type, and Associated Factors of Thyroid Dysfunction in Patients with Heart Failure in Sub-Saharan Africa: A Cross-Sectional Study

Abstract

Background: Various thyroid abnormalities have been reported during heart failure (HF). The present study aimed to evaluate the burden, type, and associated factors of thyroid disorders in Cameroonian patients with heart failure. Materials and Methods: We conducted a cross-sectional study from January to May 2020, involving volunteer adults followed for heart failure at the Yaoundé Central Hospital. Those receiving treatment that could cause thyroid dysfunction were excluded. Thyroid hormone levels (TSH, free T3, and free T4) were measured by enzyme-linked immunosorbent assay. Results: A total of 63 patients (30 women; 47.6%) were included. The median age was 65 (IQR: 56 - 70) years. The main etiology of heart failure was hypertension (52.4%) followed by valvular heart disease (14.3%). Thyroid dysfunction was seen in 38 (60.3%, [95% CI: 47.2 - 72.4]) patients, of which 30 (79%) had hypothyroidism and 8 (21%) had hyperthyroidism. The most frequent thyroid dysfunction was Low T3 syndrome in 27% (95% CI: 16.6 - 39.7) of the study population followed sub-clinical hypothyroidism in 19.1% (95% CI: 10.3 - 30.9) of patients. Patients with HF and reduced ejection fraction (HFrEF) were more likely to have hypothyroidism than those with preserved ejection fraction (OR: 3.5, [95% CI: 1.2 - 9.9], p = 0.016). Also, patients with more than one hospital admission in the past 12 months were more likely to have hypothyroidism (OR: 5.3, [95% CI: 1.3 - 21.5], p = 0.013). Conclusion: The burden of thyroid dysfunction was high in this group of patients with HF. These were mainly low T3 syndrome and sub-clinical hypothyroidism. These were associated with heart failure with reduced ejection fraction and those with more than one hospitalization within the past 12-months.