Prevalence of clinical and subclinical hypothyroidism and hyperthyroidism in Latin America: A systematic review and meta-analysis

• This is the first meta-analysis of thyroid dysfunction prevalence in Latin America. • Subclinical hypothyroidism was the most prevalent condition (7.21%; 95% CI: 4.21–10.92%). • Clinical hypothyroidism affected 3.59% (95% CI: 1.65–6.21%) of the population studied. • Hyperthyroid forms showed lower prevalence rates (approximately 1.5% for both clinical and subclinical). • Substantial variability in diagnostic criteria was observed, indicating the need for standardized regional research. Thyroid disorders constitute prevalent endocrine conditions with marked epidemiological variation across Latin American countries. This systematic review and meta-analysis aimed to establish the frequency of clinical and subclinical hypothyroidism and hyperthyroidism in Latin American populations. We searched PubMed, EMBASE, Scopus, and Web of Science for observational studies reporting the prevalence of thyroid dysfunction using biochemical assessment. Methodological quality was assessed using the Munn et al. tool, and a random-effects meta-analysis was performed with a Freeman-Tukey transformation. Ten studies from five countries (n=20,381 participants) were included. Subclinical hypothyroidism was the most frequent condition (7.21%; 95% CI: 4.21–10.92%), followed by clinical hypothyroidism (3.59%; 95% CI: 1.65–6.21%). Hyperthyroidism showed lower prevalences: 1.59% (95% CI: 0.38–3.56%) for subclinical and 1.55% (95% CI: 0.23–3.93%) for clinical forms. Substantial variability in diagnostic criteria was observed across studies. These findings suggest that hypothyroid forms predominate over hyperthyroid forms in Latin America, although estimates should be interpreted as approximate due to methodological variability. More studies with standardized diagnostic criteria and probability sampling are needed to obtain precise regional prevalence estimates.