The effect of urbanization on sleep, sleep/wake routine, and metabolic health of residents in the Amazon region of Brazil

ABSTRACT

Studying communities with different levels of urbanization may further the understanding of risk factors underlying metabolic diseases. The present study is unique by comprising detailed assessment of sleep and activity, biological rhythms, and metabolic factors of men from the same geographical location and place of birth that reside in different, rural vs. town, stages of urbanization. Sleep patterns, activity, and metabolic indicators in two groups (rural, n = 22 and town/urban, n = 20) of men residing in an Amazonian community (Xapuri, Acre, Brazil) were compared. Sociodemographic, anthropometric, and metabolic variables – fasting glucose, insulin resistance, triglycerides, total HDL cholesterol, LDL cholesterol, and VLDL cholesterol – were assessed. Sleep patterns, light exposure, and physical activity levels were additionally assessed by actigraphy, plus daily activities were recorded in diaries for 10 days. Town/urban dwellers were found to have significantly higher body weight, fasting glucose, insulin levels, and insulin resistance than rural dwellers, whereas triglycerides levels were similar. Town/Urban dwellers had shorter sleep duration (p < .01) and later sleep onset and offset times (p = .01). Our findings show an association between stage of urbanization and presence of risk factors for metabolic disorders, such as overweight, insulin resistance, increased glucose levels, short sleep duration, and less natural light exposure during work times.

KEYWORDS:

• Urban
• rural
• metabolic diseases
• metabolic parameters
• sleep
• natural light exposure
• circadian routine

Acknowledgements

We would like to extend our thanks for the financial support provided by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP #2016/09582-0); Newton Fund-São Paulo Research Foundation (FAPESP), the National Council for the State Funding Agencies (CONFAP) and UK Academies, Short-term Visiting Researcher (FAPESP #2014/50977-3); Santander University Awards for Staff Mobility and FHMS ADI Travel Grant, University of Surrey - support for mini-sabbatical to Brazil; Santander Postgraduate Travel Award for C.M. Isherwood to University of Sao Paulo, Sao Paulo. Brazil.

Conflicts of interest statement

We declare no conflicts of interest.

Supplemental Material

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Additional information

Funding

We would like to extend our thanks for the financial support provided by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP #2016/09582-0); Newton Fund-São Paulo Research Foundation (FAPESP), the National Council for the State Funding Agencies (CONFAP) and UK Academies, Short-term Visiting Researcher (FAPESP #2014/50977-3); Santander University Awards for Staff Mobility and FHMS ADI Travel Grant, University of Surrey- support for mini-sabbatical to Brazil; Santander Postgraduate Travel Award for C.M. Isherwood to University of Sao Paulo, Sao Paulo. Brazil.