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

Urbanisation negatively impacts sleep health and mood in adolescents: a comparative study of female students from city and rural schools of North India

This study investigated the impact of social settings on sleep, physical and mental health in female adolescents of North India (latitude 29.5 oN; longitude 77.5 oE). Using a battery of questionnaires, we compared the chronotype, sleep-wake pattern, sleep health (e.g. sleep quality, daytime sleepiness and fatigue) and mood (via depression, anxiety and stress symptoms) in female students (age 14-18 years) from rural (N = 719) and urban (N = 1033) schools separated by about 35 km, but families had almost similar socio-demographic details. The morning type was prevalent amongst rural, whilst the evening type was prevalent amongst urban students who also had access to smart phones, suggesting a possible greater use of the internet. There were greater negative sleep effects, daytime sleepiness, overall poor sleep quality, higher fatigue and anxiety levels in urban than the rural cohort. Interestingly, these measures also differed between school days and free days, suggesting an impact of the conflict between internal biological and social timings (= social jet lag). We also found a significant relationship between chronotype, internet addiction, mood-related parameters and measures of sleep health. Overall, these results suggest a possible impact of social settings on sleep health and mood-related behaviours in female adolescents.

The relationship between sleep health and multimorbidity in community dwelling populations: Systematic review and global perspectives

Previous research has identified a relationship between sleep problems and multimorbidity, defined as the co-occurrence of two or more chronic health conditions in the same individual. This systematic review sought to summarize the literature on the association between sleep duration and quality and multimorbidity in adult community-dwelling populations. A comprehensive search of the PubMed, Embase and CINAHL databases identified studies published between January 1990 and January 2023. Studies were included if they focused on community-dwelling populations, used an observational design, measured sleep quality or duration, used multimorbidity as the main study outcome, and explored the relationship between sleep and multimorbidity. Two reviewers independently conducted study screening, data extraction, and bias assessments. Twenty-four cross-sectional and five prospective cohort studies met the inclusion criteria, with studies from 16 countries and two with cross-country comparisons, and a total participant number of 481,862. Overall, poorer sleep quality and sleep duration outside current recommendations were consistently associated with multimorbidity, though with varying strength. This association was present regardless of specific multimorbidity definitions from different studies. Definitions of sleep duration and quality were inconsistent across studies, possibly contributing to mixed evidence on the observed association. Most studies were cross-sectional, limiting the assessment of the temporal direction of association. Our results corroborate relationships between poor sleep and risk of multimorbidity in adult community-dwelling populations around the world. Examining this relationship may help increase public health awareness of sleep as a modifiable risk factor for the prevention of chronic disease and healthy aging.

Association between urbanization and Internet addiction

PURPOSE OF REVIEW

Understanding the association between urbanization and Internet addiction is essential to the design and implementation of Internet addiction prevention measures in urban areas. This epidemiological review explores the urbanization-Internet addiction association and its potential underlying factors.

RECENT FINDINGS

Nine studies have reported that Internet addiction prevalence is higher in urban areas, but three studies have noted the opposite. Psychiatric disorders and stress are the most commonly mentioned factors underlying the association. The effects of urbanization on Internet availability, Internet cafes, online gaming, outdoor or interactive activities, and family regulation and monitoring have been suggested to lead to higher Internet addiction risk. The ongoing COVID-19 pandemic, obesity, sleep problems, and the migration of parents to urban areas in search of work have strengthened the effect of urbanization on Internet addiction.

SUMMARY

Early assessment and treatment provided by mental health services are crucial for mitigating the effect of urbanization on Internet addiction risk. Cities should be designed to provide adequate space for physical and interactive activities. To promote outdoor activities, air pollution, traffic congestion, and crime should be controlled. Prospective face-to-face studies involving analysis of data on pollution, traffic, and Internet addiction could provide evidence to elucidate the urbanization- Internet addiction association.

Relationship Between Circadian Strain, Light Exposure, and Body Mass Index in Rural and Urban Quilombola Communities

Industrialization has greatly changed human lifestyle; work and leisure activities have been moved indoors, and artificial light has been used to illuminate the night. As cyclic environmental cues such as light and feeding become weak and/or irregular, endogenous circadian systems are increasingly being disrupted. These disruptions are associated with metabolic dysfunction, possibly contributing to increased rates of overweight and obesity worldwide. Here, we aimed to investigate how activity-rest rhythms, patterns of light exposure, and levels of urbanization may be associated with body mass index (BMI) in a sample of rural and urban Quilombola communities in southern Brazil. These are characterized as remaining social groups who resisted the slavery regime that prevailed in Brazil. Quilombola communities were classified into five groups according to their stage of urbanization: from rural areas with no access to electricity to highly urbanized communities. We collected anthropometric data to calculate BMI, which was categorized as follows: from ≥ 18.5 kg/m² to < 25 kg/m² = normal weight; from ≥ 25 kg/m² to < 30 kg/m² = overweight; and ≥ 30 kg/m² = obese. Subjects were asked about their sleep routines and light exposure on workdays and work-free days using the Munich Chronotype Questionnaire (N = 244 included). In addition, we analyzed actimetry data from 121 participants with seven consecutive days of recordings. Living in more urbanized areas and higher intradaily variability (IV) of activity-rest rhythms were associated with an increased risk of belonging to the overweight or obese group, when controlling for age and sex. These findings are consistent with preclinical data and point to potential strategies in obesity prevention and promotion of healthy metabolic profiles.

Sleep Under Preindustrial Conditions: What We Can Learn from It

Human sleep is regulated by light in two fundamental ways: The light-dark (LD) cycle entrains a circadian clock that in turn regulates sleep timing, and light per se can acutely inhibit sleep. Throughout evolution, these sleep regulatory systems became highly sensitive to the effects of light and they can be affected by the relatively low light intensities that are used indoors. Thus, postindustrial living conditions have created built environments that have isolated humans from the natural LD cycle and exposed them to an artificial one that can affect daily sleep timing. Studying indigenous communities that have differential access to electricity, as well as communities living in highly urbanized areas, we and others have shown that human access to artificial light has delayed the daily onset of sleep but has had a smaller effect on its offset, leading to an overall reduction in sleep duration that is pervasive in modern societies. In this chapter we discuss these studies, highlight their main findings, and point to their limitations.

Circadian preference and its relationship with possible sleep and awake bruxism in adults assisted by the public health system

Modern lifestyle and social demands induce changes in sleep routines that may not meet individual circadian preferences (chronotype). Such changes may be associated with the development of unhealthy lifestyles and the emergence of diseases relevant to public health services, such as obesity, hypertension, and diabetes mellitus, as well as sleep bruxism (SB) and awake bruxism (AB). The present study aimed to assess the relationship between the evening, morning or intermediate chronotypes with the report of possible SB and AB in adult individuals assisted by the Family Health Strategy (FHS). The selection of participants was performed through probabilistic cluster analysis. The sample size (n = 384) was calculated to include a representative sample of the 52,628 adults registered in the FHS of a countryside city located in the Southeast Region of Brazil. The Morningness-Eveningness Questionnaire (MEQ) was used to determine the chronotype, and Questionnaire-Based Self-Reported Bruxism was used for identifying possible SB and AB. The following clinical and social-behavioral variables were also evaluated: age, sex, BMI, income, physical activity, schooling, alcohol consumption and smoking, chronic diseases and depression. Two logistic regression models were used: one for SB and one for AB. Possible SB was associated with female sex, lack of physical activity and income above 2 minimum wages. Regarding chronotype, a 19% reduction in the chance of possible SB was observed in morning individuals compared to evening individuals (p = .017). Possible AB was associated with younger individuals, smoking and depression. In conclusion, compared with the evening circadian preference, the morning circadian preference was associated with greater protection against possible SB in an adult population assisted by the FHS.