The impact of urbanisation on the cardiometabolic health of Indigenous Brazilian peoples: a systematic review and meta-analysis, and data from the Brazilian Health registry

• Published in: The Lancet (British edition) 2022-12, Vol.400 (10368), p.2074-2083
• Main Authors: Kramer, Caroline K, Leitão, Cristiane B, Viana, Luciana V
• Format: Article
• Language: English
• Subjects: Adult; Adults; Age; Aged; Aging; Aging (natural); Bias; Blood Pressure; Cardiovascular diseases; Cardiovascular Diseases - epidemiology; Culture; Deforestation; Diabetes; Ecosystem; Environmental policy; Ethnicity; Evaluation; Female; Health policy; Health risks; Humans; Hypertension; Hypertension - epidemiology; Indigenous peoples; Infectious diseases; Lifestyles; Literature reviews; Male; Men; Meta-analysis; Metabolism; Mortality; Native peoples; Obesity; Observational studies; Pediatrics; Policies; Rainforests; Reviews; Risk analysis; Risk factors; Systematic review; Urban areas; Urbanization; Women
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(22)00625-0

Indigenous Brazilian peoples have faced an unparalleled increase in the rate of cardiovascular diseases following rapid nutritional transition to more urban diets. We aimed to conduct a systematic review and meta-analysis to evaluate the association between urbanisation (including data from Amazon rainforest deforestation) and cardiometabolic risk factors and outcomes. In this systematic review and meta-analysis, we searched Pubmed, Embase, Web of Science, and Scopus for articles published in any language between the year 1950 and March 10, 2022. Studies conducted in Indigenous Brazilian adults that evaluated metabolic health were included. Data for deforestation was obtained by the Amazon Deforestation Monitoring Project. Cardiovascular mortality was obtained from the Brazilian Health registry. Two independent reviewers evaluated studies for risk of bias, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. The main outcomes assessed were the prevalence of obesity and related cardiometabolic risk factors among Indigenous Brazilian peoples and its association with urbanisation. Summary data were extracted from published reports for the meta-analyses. We calculated pooled estimates of the prevalence of each cardiometabolic outcome by using a random-effects model (DerSimonian–Laird method). This study is registered with the International Prospective Register of Systematic Reviews, CRD42021285480. 46 studies were identified, including a total of 20 574 adults from at least 33 Indigenous Brazilian ethnicities. Meta-analyses of the prevalence of obesity showed that there were higher rates of obesity (midwest region: 23% [95% CI 17–29]; and south region 23% [13–34]) and hypertension (south region: 30% [10–50]) in Indigenous peoples living in urban regions of Brazil, while the lowest rates of obesity (11% [95% CI 8–15]) and hypertension (1% [1–2]) were observed in those in the less urbanised (north) regions of Brazil. The prevalence of obesity was 3·5 times higher in participants living in urbanised Indigenous territories (28%) than in those living in lands with >80% native Amazon rainforest (8%). In meta-analyses that evaluated blood pressure level, there was no incremental change in blood pressure with ageing in Indigenous peoples who lived according to traditional lifestyle, in contrast to those living in urbanised regions. For Indigenous men with traditional lifestyles, systolic blood pressure changed from 109·8