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1. Clustering of longitudinal physical activity trajectories among young females with selection of associated factors

   https://doi.org/10.1371/journal.pone.0268376  

   Yang, Luoying ; Young, Deborah R. ; Wu, Tong Tong ( May 2022 , PLOS ONE)

   Harezlak, Jaroslaw (Ed.)

   We examined multi-level factors related to the longitudinal physical activity trajectories of adolescent girls to determine the important predictors for physical activity. The Trial of Activity in Adolescent Girls (TAAG) Maryland site recruited participants at age 14 ( n = 566) and followed up with these girls at age 17 ( n = 553) and age 23 ( n = 442). Individual, social factors and perceived environmental factors were assessed by questionnaire; body mass index was measured at age 14 and age 17, and self-reported at age 23. Neighborhood factors were assessed by geographic information systems. The outcome, moderate-to-vigorous physical activity (MVPA) minutes in a day, was assessed from accelerometers. A mixture of linear mixed-effects models with double penalization on fixed effects and random effects was used to identify the intrinsic grouping of participants with similar physical activity trajectory patterns and the most relevant predictors within the groups simultaneously. Three clusters of participants were identified. Two hundred and forty participants were clustered as “maintainers” and had consistently low MVPA over time; 289 participants were clustered as “decreasers” who had decreasing MVPA over time; 39 participants were grouped as “increasers” and had increasing MVPA over time. Each of the three clusters has its own cluster-specific factors identified using the clustering method, indicating that each cluster has unique characteristics. 

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2. Lifestyle and patterns of physical activity in Hadza foragers

   https://doi.org/10.1002/ajpa.24846  

   Sayre, M. Katherine ; Anyawire, Mariamu ; Paolo, Bunga ; Mabulla, Audax Z. P. ; Pontzer, Herman ; Wood, Brian M. ; Raichlen, David A. ( September 2023 , American Journal of Biological Anthropology)

   Physically active lifestyles are associated with several health benefits. Physical activity (PA) levels are low in post‐industrial populations, but generally high throughout life in subsistence populations. The Hadza are a subsistence‐oriented foraging population in Tanzania known for being physically active, but it is unknown how recent increases in market integration may have altered their PA patterns. In this study, we examine PA patterns for Hadza women and men who engage in different amounts of traditional foraging.

   One hundred and seventy seven Hadza participants (51% female, 19–87 years) wore an Axivity accelerometer (dominant wrist) for ~6 days during dry season months. We evaluated the effects of age, sex, and lifestyle measures on four PA measures that capture different aspects of the PA profile.

   Participants engaged in high levels of both moderate‐intensity PA and inactivity. Although PA levels were negatively associated with age, older participants were still highly active. We found no differences in PA between participants living in more traditional “bush” camps and those living in more settled “village” camps. Mobility was positively associated with step counts for female participants, and schooling was positively associated with inactive time for male participants.

   The similarity in PA patterns between Hadza participants in different camp types suggests that high PA levels characterize subsistence lifestyles generally. The sex‐based difference in the effects of mobility and schooling on PA could be a reflection of the Hadza's gender‐based division of labor, or indicate that changes to subsistence‐oriented lifestyles impact women and men in different ways.

    

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3. Age-related change in adult chimpanzee social network integration

   https://doi.org/10.1093/emph/eoab040  

   Thompson González, Nicole ; Machanda, Zarin ; Otali, Emily ; Muller, Martin N. ; Enigk, Drew K. ; Wrangham, Richard ; Emery Thompson, Melissa ( December 2021 , Evolution, Medicine, and Public Health)

   Social isolation is a key risk factor for the onset and progression of age-related disease and mortality in humans. Nevertheless, older people commonly have narrowing social networks, with influences from both cultural factors and the constraints of senescence. We evaluate evolutionarily grounded models by studying social aging in wild chimpanzees, a system where such influences are more easily separated than in humans, and where individuals are long-lived and decline physically with age.

   We applied social network analysis to examine age-related changes in social integration in a 7+ year mixed-longitudinal dataset on 38 wild adult chimpanzees (22 females, 16 males). Metrics of social integration included social attractivity and overt effort (directed degree and strength), social roles (betweenness and local transitivity) and embeddedness (eigenvector centrality) in grooming networks.

   Both sexes reduced the strength of direct ties with age (males in-strength, females out-strength). However, males increased embeddedness with age, alongside cliquishness. These changes were independent of age-related changes in social and reproductive status. Both sexes maintained highly repeatable inter-individual differences in integration, particularly in mixed-sex networks.

   As in humans, chimpanzees appear to experience senescence-related declines in social engagement. However, male social embeddedness and overall sex differences were patterned more similarly to humans in non-industrialized versus industrialized societies. Such comparisons suggest common evolutionary roots to ape social aging and that social isolation in older humans may hinge on novel cultural factors of many industrialized societies. Lastly, individual and sex differences are potentially important mediators of successful social aging in chimpanzees, as in humans.

   Lay summary: Few biological models explain why humans so commonly have narrowing social networks with age, despite the risk factor of social isolation that small networks pose. We use wild chimpanzees as a comparative system to evaluate models grounded in an evolutionary perspective, using social network analysis to examine changes in integration with age. Like humans in industrialized populations, chimpanzees had lower direct engagement with social partners as they aged. However, sex differences in integration and older males’ central positions within the community network were more like patterns of sociality in several non-industrialized human populations. Our results suggest common evolutionary roots to human and chimpanzee social aging, and that the risk of social isolation with age in industrialized populations stems from novel cultural factors.

    

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4. Physical Activity and Pregnancy Norms Among Daasanach Semi‐Nomadic Pastoralist Women in Northern Kenya

   https://doi.org/10.1002/ajhb.24174  

   Sadhir, Srishti ; McGrosky, Amanda ; Ford, Leslie B. ; Nzunza, Rosemary ; Wemanya, Sylvia N. ; Mashaka, Husna ; Kinyanjui, Rahab N. ; Ndiema, Emmanuel ; Braun, David R. ; Rosinger, Asher Y. ; et al ( October 2024 , American Journal of Human Biology)

   In subsistence populations, high physical activity is typically maintained throughout pregnancy. Market integration shifts activity patterns to resemble industrialized populations, with more time allocated to sedentary behavior. Daasanach semi‐nomadic pastoralists living in northern Kenya face lifestyle heterogeneity due to the emergence of a market center. We investigate how Daasanach women manage the energetic demands of pregnancy with subsistence labor tasks and how market integration relates to variation in energetic demands, physical activity, and coping strategies.

   We conducted nine focus group discussions with 72 pregnant women. We also deployed wrist‐worn fitness trackers with 21 pregnant women in two community types: central or peripheral to the market center to capture variation in market integration. Data from focus group discussions were analyzed using thematic analysis. We used multiple linear regression to examine the relationship between gestational age and physical activity.

   We identified themes of increased fatigue, diet restrictions, and assistance with labor tasks during pregnancy. Gestational age negatively predicted mean daily steps, with a decrease of 1160 ± 437 steps per day with each consecutive pregnancy month. Stratified by community type, gestational age only negatively predicted mean daily steps for peripheral communities, with a decrease of 1443 ± 629 steps per day with each consecutive pregnancy month.

   Results suggest that physical activity differs with market integration early, but not late, in pregnancy. Daasanach women cope with the energetic demands of pregnancy by reducing physical activity late in pregnancy and receiving assistance with labor tasks from family and neighbors.

    

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5. Using functional principal component analysis (FPCA) to quantify sitting patterns derived from wearable sensors

   https://doi.org/10.1186/s12966-024-01585-8  

   Zablocki, Rong W ; Hartman, Sheri J ; Di, Chongzhi ; Zou, Jingjing ; Carlson, Jordan A ; Hibbing, Paul R ; Rosenberg, Dori E ; Greenwood-Hickman, Mikael Anne ; Dillon, Lindsay ; LaCroix, Andrea Z ; et al ( December 2024 , International Journal of Behavioral Nutrition and Physical Activity)

   Sedentary behavior (SB) is a recognized risk factor for many chronic diseases. ActiGraph and activPAL are two commonly used wearable accelerometers in SB research. The former measures body movement and the latter measures body posture. The goal of the current study is to quantify the pattern and variation of movement (by ActiGraph activity counts) during activPAL-identified sitting events, and examine associations between patterns and health-related outcomes, such as systolic and diastolic blood pressure (SBP and DBP).

   The current study included 314 overweight postmenopausal women, who were instructed to wear an activPAL (at thigh) and ActiGraph (at waist) simultaneously for 24 hours a day for a week under free-living conditions. ActiGraph and activPAL data were processed to obtain minute-level time-series outputs. Multilevel functional principal component analysis (MFPCA) was applied to minute-level ActiGraph activity counts within activPAL-identified sitting bouts to investigate variation in movement while sitting across subjects and days. The multilevel approach accounted for the nesting of days within subjects.

   At least 90% of the overall variation of activity counts was explained by two subject-level principal components (PC) and six day-level PCs, hence dramatically reducing the dimensions from the original minute-level scale. The first subject-level PC captured patterns of fluctuation in movement during sitting, whereas the second subject-level PC delineated variation in movement during different lengths of sitting bouts: shorter (< 30 minutes), medium (30 -39 minutes) or longer (> 39 minute). The first subject-level PC scores showed positive association with DBP (standardized$$\hat{\beta }$$$\hat{\beta }$: 2.041, standard error: 0.607, adjustedp= 0.007), which implied that lower activity counts (during sitting) were associated with higher DBP.

   In this work we implemented MFPCA to identify variation in movement patterns during sitting bouts, and showed that these patterns were associated with cardiovascular health. Unlike existing methods, MFPCA does not require pre-specified cut-points to define activity intensity, and thus offers a novel powerful statistical tool to elucidate variation in SB patterns and health.

   ClinicalTrials.gov NCT03473145; Registered 22 March 2018;https://clinicaltrials.gov/ct2/show/NCT03473145; International Registered Report Identifier (IRRID): DERR1-10.2196/28684

    

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