Heterogeneous burden of hypertension among Brazilian indigenous populations: a systematic review and meta-analysis

Background Hypertension (HTN) is a major public health issue, with increasing prevalence among Brazilian Indigenous adults, yet its distribution and underlying patterns remain insufficiently characterized. In these populations, social and structural factors, including urbanization and access to healthcare, may play an important role in shaping cardiovascular risk. This study aimed to systematically assess HTN prevalence and explore patterns across different populations. Methods We conducted a systematic review and meta-analysis of population-based cross-sectional studies reporting HTN prevalence among Indigenous adults in Brazil. Five databases were searched without language restrictions. Study selection and data extraction were performed independently by two reviewers. Random-effects models were used to estimate pooled prevalence, and subgroup analyses and meta-regression were conducted to explore sources of heterogeneity. This review was registered in PROSPERO (CRD42024626440). Results Twenty-two studies (1989 to 2024), comprising 9,449 Indigenous adults, were included in the systematic review. Seventeen population-specific estimates, comprising 5,908 individuals and 1,209 with HTN, met the predefined diagnostic criteria and were included in the primary meta-analysis. The pooled HTN prevalence was 8.2% (95% CI, 3.9–16.4%), with substantial between-estimate heterogeneity (I²=94.3%; 95% prediction interval, 0.3–73.2%). Studies with a mean age ≥ 40 years showed a higher pooled prevalence (19.5%) than those with a mean age < 40 years (3.6%). Meta-regression identified year of data collection and mean age as significant moderators, explaining 39.1% and 17.1% of between-estimate heterogeneity, respectively. Geographic region and area of residence were not significant moderators. The substantial heterogeneity and incomplete reporting of relevant population characteristics limited the interpretation of contextual factors. Conclusion HTN prevalence among Brazilian Indigenous populations was highly heterogeneous across the populations represented in the available evidence. Although differences were observed according to age, geographic context, and study period, these findings should not be interpreted as population-level regional estimates or as evidence of an independent effect of urbanization. Substantial heterogeneity and methodological limitations restrict causal inference and precise estimation of HTN prevalence across all Brazilian Indigenous populations. These findings highlight the need for standardized, culturally sensitive research and context-specific public health strategies addressing hypertension prevention, screening, management, and health disparities.