Journal of Physiological Anthropology最新文献

Study objectives: Nonrestorative sleep (NRS) has been identified as a potential risk factor for physical and mental well-being in adults, but limited research exists for children and adolescents. This study aimed to clarify the factors associated with NRS in Japanese junior high school students.

Methods: The participants were 529 Japanese junior high school students in grades 7 through 9. Participants were asked to respond to Google Forms, and responses were obtained from 392 students. Sleep habits, history of coronavirus disease (COVID-19), physical symptoms, social isolation, and the presence of the symptoms of restless legs syndrome (RLS) were identified. NRS, insomnia symptoms, and depressive symptoms were evaluated using the Restorative Sleep Questionnaire (RSQ), Athens Insomnia Scale (AIS), and Patient Health Questionnaire (PHQ)-9, respectively. The cut-off value for NRS determination by the RSQ score was the mean of the scores that maximized the sensitivity and specificity sum for detecting participants with AIS and PHQ-9 scores of ≥ 6 and ≥ 5, respectively. NRS-associated sleep parameters and those associated with depressive symptoms were evaluated using binominal logistic regression analysis. Multinomial logistic regression (MLR) analysis was used to confirm the reproducibility of the binomial logistic regression analysis results with lower RSQ scores.

Results: The NRS group comprised 40.1% of participants and exhibited a higher prevalence of physical and depressive symptoms compared to those with restorative sleep. Logistic regression analysis, adjusted for sex, grade, and COVID-19 history, revealed the following odds ratios (95% confidence interval) for NRS: average total sleep time < 7 h 2.44 (1.16-4.33), AIS ≥ 6 2.74 (1.51-4.95), evening chronotype 2.58 (1.49-4.47), and RLS symptoms 2.21 (1.21-4.03). The same results were obtained using MLR as those obtained via binomial logistic regression analysis. Logistic regression analysis for depressive symptoms revealed that NRS displayed the highest odds ratio (95% CI) of 3.16 (1.90-5.27) among the sleep-related variables.

Conclusions: These findings suggest that NRS in Japanese junior high school students is associated with physical and mental health issues. Intervention and longitudinal studies are warranted to address NRS-associated sleep-wake problems in this age group.

Background: Omentin-1 (also known as intelectin-1) is a novel adipokine associated with metabolic diseases. However, its physiological role in body composition remains incompletely understood. Therefore, this study aimed to investigate the association between the circulating omentin-1 levels and whole-body and regional body composition parameters measured using dual-energy X-ray absorptiometry (DXA).

Methods: A population-based cross-sectional survey was conducted among school-aged children in Hamamatsu, Japan. Serum adipokine levels were measured using enzyme-linked immunosorbent assay, and associations between omentin-1 levels and DXA-based parameters were evaluated by multiple regression analysis after adjusting for potential confounding factors.

Results: The final study included 392 participants (192 boys, 200 girls, 75.2% of the source population; mean age 11.2 ± 0.3 years). Serum omentin-1 levels showed a significantly inverse association with nearly all DXA-based fat mass parameters. Inverse correlations were observed with fat-free soft tissue mass and serum leptin levels, whereas positive correlations were noted with adiponectin levels. The mean values for various body fat parameters, fat-free soft tissue mass, body mass index, and waist circumference were significantly decreased across tertiles of serum omentin-1 levels from lowest to the highest after adjusting for potential confounders.

Conclusion: Our results demonstrate that Japanese school-aged children with higher fat mass tended to have lower serum omentin-1 levels. These findings provide crucial insights into the link between omentin-1 levels and body composition, which may contribute to early health interventions for metabolic improvement.

Background: The thermos-physiological characteristics of medical personnel wearing protective clothing during prolonged activities under low oxygen pressure (LOP) and normal oxygen pressure (NOP) are crucial.

Methods: The average age of the 24 participants was 22.13 ± 1.849 years, with an average height of 168.58 ± 6.268 cm, an average weight of 61.62 ± 8.128 kg, and an average BMI of 21.59 ± 1.761 kg/m². Participants were first exposed to an LOP environment. The 6-h experiment involved a three-phase cycle (sitting, walking, and cardiopulmonary resuscitation (CPR)) repeated every hour. After a 2-week washout period, 24 participants were exposed to a NOP environment and repeated the aforementioned experimental procedure. Logistic regression and Cox analysis were used to assess the relationship between different oxygen pressures and human indicators. Restricted cubic spline (RCS) analysis was employed to examine the temporal changes in physiological indicators, and the Kaplan-Meier (K-M) method was used to plot survival curves.

Results: Each observation time point identified 120 min as the optimal protection time, with the greatest intergroup differences observed for both continuous (5/8 variables) and categorical (8/12 variables) parameters at this time point. Stepwise Regression analyses combining logistic and Cox regression identified six significant variables (P < 0.05): temperature, SpO₂, pulse pressure, thermal sensation vote (TSV), sultriness, and rating of perceived exertion (RPE). K-M analysis revealed significantly higher probabilities of adverse outcomes in the LOP group compared to the NOP group: SpO₂ abnormalities (HR = 1.439, 95% CI: 1.026-2.017; log-rank P = 0.022), High TSV scores (HR = 2.463 [1.537-3.946]; P < 0.001), High sultriness scores (HR = 1.603 [1.260-2.040]; P < 0.001). RCS analysis of LOP group data showed significant temporal effects: RPE exhibited a nonlinear upward trend (overall P < 0.001; nonlinear P = 0.002), reaching an inflection point at 200 min. SpO₂ demonstrated linear decline (P = 0.002/0.143; inflection point = 200 min). Pulse pressure showed covariate-dependent effects: nonsignificant before adjustment (P = 0.430) but significant after adjustment (P = 0.008/0.891; inflection point = 200 min).

Conclusions: Our research shows that 120 ~ 200 min is an optimal working time that does not affect the work efficiency of medical personnel.

Cold constitution refers to a phenomenon in which individuals have a higher sensitivity to cold and feel colder than others. This research aimed to examine the associations of morphological characteristics, personal factors, thermal perceptions, and local skin temperature (t_sk) with cold constitution by conducting a field experiment. It also explored differences in these aspects between individuals with and without cold constitution, in a thermoneutral office environment during summer and winter, and in 89 and 75 sedentary workers, respectively. A questionnaire survey was conducted to classify the cold constitution (CC) and non-cold constitution (NC) groups. The results indicated that females and individuals with lower body mass index (BMI) were more likely to have cold constitution. The CC group exhibited a significantly lower metabolic rate (M) in both seasons, lower thermal sensation votes, warmer thermal preference, and a greater predicted percentage of dissatisfied in summer (p < 0.01). No significant differences were observed in clothing insulation between the groups; however, winter clothing was significantly higher compared to summer for both groups (p < 0.01). Furthermore, the CC group exhibited significantly lower local skin temperatures at distal body parts (p < 0.01). Significant correlations were observed for gender, BMI, M, thermal sensations, and distal t_sk with cold constitution. Adjusting the effects of gender and BMI, most correlations with cold constitution weakened. However, thermal sensation remained significant in summer, while no correlation was observed with t_sk. These findings emphasize the significant associations of morphological characteristics, personal factors, and thermal perceptions with cold constitution and show the importance of assessing the thermal environment.

Background: Nutrition is a modifiable factor in skin ageing, but its effects remain inconsistently quantified. This meta-analysis assessed human studies from the Web of Science on dietary intake and skin ageing, using pooled standardised mean differences (pSMD). Interventions included carotenoids, collagen, lipids and fatty acids, polyphenols, prebiotics and probiotics, and vitamins. We included full-text English articles and excluded non-human, disease-focused, topical or in vitro studies. Publication bias was assessed using Egger's test and funnel plots. Results are shown as forest plots.

Main body: Sixty-one studies were meta-analysed. Collagen reduces wrinkles (pSMD = - 0.94 [- 1.39, - 0.49], p = 4.82 × 10^-5). Lipids and fatty acids (pSMD = - 0.62 [- 0.92, - 0.31], p = 7.89 × 10^-5) and polyphenols (pSMD = - 0.48 [- 0.74, - 0.21], p = 3.96 × 10^-4) also reduce wrinkles without significant publication bias. Several interventions improve skin hydration, including collagen (pSMD = 0.66 [0.29, 1.04], p = 5.99 × 10^-4), lipids and fatty acids (pSMD = 0.54 [0.28, 0.80], p = 4.36 × 10^-5), polyphenols (pSMD = 0.59 [0.37, 0.80], p = 6.43 × 10^-8), and prebiotics and probiotics (pSMD = 0.71 [0.25, 1.16], p = 2.64 × 10^-3). Specific interventions target distinct ageing phenotypes. Carotenoids most effectively reduce redness (pSMD = - 0.53 [- 1.02, - 0.04], p = 3.39 × 10^-2), and collagen reduces pigment spots (pSMD = - 0.16 [- 0.31, - 0.003], p = 4.56 × 10^-2). Lipids and fatty acids improve elasticity (pSMD = 0.49 [0.14, 0.83], p = 5.45 × 10^-3), while polyphenols strengthen barrier integrity (trans-epidermal water loss pSMD = - 0.50 [- 0.79, - 0.22], p = 6.39 × 10^-4).

Conclusion: Dietary components target specific skin ageing phenotypes. Carotenoids, collagen, lipids and fatty acids, and polyphenols are particularly effective for redness, pigment spots, elasticity, and barrier integrity, respectively. Lipids, fatty acids, and polyphenols show broad benefits across multiple phenotypes. Shared mechanisms may contribute to overlapping effects. Evidence gaps remain, especially regarding carotenoids and vitamins. Future studies could explore combinatorial dietary interventions. This research is primarily supported by a Singapore National Medical Research Council grant.

The recent Journal of Physiological Anthropology article on polycythemia among Tibetan highlanders (Arima et al., J Physiol Anthropol 43:25, 2024) piqued our interest because we collected similar data in the same Nepali village in Upper Mustang two years later with notably different results (Cho et al., Evol Med Public Health 2017:82-96, 2017; Ye et al., Proc Natl Acad Sci U S A 121:e2403309121, 2024). Arima et al report high prevalences of chronic disease and conclude that Tsarang villagers have poor health. Here, we describe our relevant findings to show that authors' definitions and other research design elements can yield different population health implications. Our study sampled ethnic Tibetan Upper Mustang women 39 Years and older in 2012 who had been married or pregnant and were lifelong residents of this village at 3500m. At our 2019 follow-up study, the women were 46 Years and older. Fifty-five of the 64 eligible Tsarang residents (85%) participated in 2019 study designed to examine the influences of genes and physiology on reproductive success. Arima et al. sampled all Tsarang residents 18 or older in 2017, therefore, our studies include many of the same women in their mid-40s and older. Arima et al reported that 12% of the sample were polycythemic, whereas we found none; they reported 26% obesity whereas we found none; they showed 17% of the sample had hypertension, whereas we found 27%. Factors that may account for the differences in estimates of chronic disease prevalence in Tsarang include age differences in the samples, a wider age range in the currently reported sample, undefined cut-off values for disease categories, while we applied and reported chronic diseases using standard definitions. Because our study did not replicate the findings of Arima et al., we caution against concluding that women in Tsarang have alarming rates of obesity, polycythemia, and hypoxia. Our studies agree that high blood pressure is a public health problem among women in Tsarang. Future use of clear definitions of disease categories will help establish a common understanding of a population's health.

Background: Cold-induced vasodilation (CIVD) reduces the risk of local cold injuries. There are obvious differences in CIVD characteristics among different ethnic groups. This study aimed to compare cold tolerance manifested through CIVD responses in indigenous Tibetans and Han residents in Tibet.

Methods: A total of 12 Tibetans and 10 Han individuals (residence duration at high altitude > 5 years) from high altitudes were recruited in the study. The CIVD test was performed by immersing the participants' middle finger of the non-dominant hand in cold water (0 ℃) for 30 min followed by recovery for 10 min at a temperature of 25 ± 1 ℃. During the CIVD tests, the participants provided perceptual responses for the immersed hand every 5 min. The participants completed their baseline questionnaires and physiological assessments before the start of the CIVD test, and they completed their hematological tests the following morning.

Results: Compared with Hans at high altitude, Tibetans had higher minimum temperature (T_min), maximum temperature (T_max), and Resistance Index for Frostbite (RIF) scores (p < 0.05), and warmer perceptual responses (p < 0.05). We found that red blood cell (RBC) count, hemoglobin (HGB) and hematocrit (HCT) were positively correlated with onset time (Δt_onset), peak time (Δt_peak), frequency of CIVD waves (CIVD_waves), and negatively correlated with T_min, T_max, mean finger temperature (T_mean) in the general population (p < 0.05), whereas these correlations were not observed in the Tibetan and Han populations (p > 0.05). However, the basophil percentage (BAS%), neutrophil percentage (NEU%) and γ-glutamyl transpeptidase (GGT) levels (p < 0.05) correlated with the RIF score in Han population.

Conclusion: Compared with Hans at high altitude, indigenous Tibetans demonstrated superior local cold resistance phenotypes in vasomotor regulation, evidenced by their distinct CIVD and perceptual responses. Hematological and biochemical parameters, erythrocytosis is a critical determinant of local cold tolerance at high altitude in the general population. BAS%, NEU%, and GGT are related to local cold tolerance in Han residents.

Purpose: There are no previous reports investigating the effects of different set numbers in low-intensity resistance exercise with slow movement and tonic force generation (LST) on muscle fatigue using surface electromyography (sEMG). This study aimed to examine muscle fatigue induced by one set and three sets of LST and to compare the impact of set differences on muscle activity by comparing LST with traditional high-intensity resistance exercise (TRAD).

Methods: Twenty-three healthy male students participated in this study. After 1RM testing in each leg was completed, participants were randomly assigned to either a group performing one set of exercises (n = 10) or a group performing three sets (n = 13). Each participant performed the LST protocol (50% 1RM) and the TRAD protocol (80% 1RM) with single leg extension until failure. The LST protocol consisted of a 3-s concentric, a 1-s isometric, and a 3-s eccentric phase. In contrast, the TRAD protocol consisted of a 1-s concentric, a 1-s eccentric, and a 1-s rest phase. For the three-set group, a 2-min rest interval was provided between sets. The outcome measures included maximal isometric knee extension torque (MVC) before and after exercise, root mean square (RMS), and mean power frequency (MPF) values recorded during the exercises.

Results: No significant differences in MVC were observed between the type of exercise or the number of sets. Similarly, no significant differences in the RMS during the exercise were observed across exercise types or number of sets. On the other hand, with the significant interaction of MPF (p = 0.001, η_p² = 0.399), there was a significant difference in three sets of LST compared to one set of LST (p = 0.012, d = 1.16) and three sets of TRAD (p < 0.001, d = 0.93).

Conclusion: Our findings suggest that performing three sets of LST induces significant muscle fatigue. Therefore, we speculate that performing three sets of LST may lead to the accumulation of metabolic stress and thereby cause muscle fatigue.

Introduction: This study aimed to explore the effects of a single mild-dose, acute hyperbaric oxygen (HBO) intervention (1.3 ATA, 100% oxygen, 60 min) on aerobic endurance, cardiac function, pulmonary function, and autonomic nervous system balance in healthy young men.

Methods: Using a randomized crossover design, 14 participants received both the HBO intervention and the control condition (seated rest). For each condition, heart rate variability (HRV), cardiac function, and pulmonary function were assessed before and after the intervention, while aerobic endurance indicators-such as peak oxygen uptake (VO₂peak) and time to exhaustion (TTE)-were measured once following each condition.

Results: HBO significantly decreased resting heart rate (from 63.64 ± 7.75 to 58.79 ± 7.29 bpm, Δ = -7.23%, p = 0.009), with a significant main effect of time (F(1,13) = 7.657, p = 0.016, η²ₚ = 0.371) and a significant time × condition interaction effect (F(1,13) = 4.51, p = 0.048, η²ₚ = 0.268). Root mean square of successive differences (RMSSD) increased from 44.50 [24.50, 59.75] to 54.00 [35.50, 67.50] (Z = 2.261, p = 0.024, r = - 0.604), and standard deviation of successive differences (SDSD) increased from 55.50 [31.75, 76.50] to 71.00 [55.75, 87.75] (Z = 2.701, p = 0.007, r = - 0.722). Both parameters also demonstrated significant differences in condition comparisons (RMSSD: Z = - 2.826, p = 0.005, r = - 0.755; SDSD: Z = - 2.796, p = 0.005, r = - 0.747). No significant changes were observed in aerobic endurance, pulmonary function, or other cardiac function parameters.

Conclusion: A single mild-dose, acute HBO intervention can significantly improve resting heart rate and enhance short-term HRV parameters, suggesting a beneficial effect on parasympathetic activity. However, it does not directly enhance aerobic endurance, and long-term interventions or combined training may be needed to realize its potential benefits.

Background: Excessive fatigue, sleep deprivation, and poor intershift recovery after night shifts are associated with an increased risk of traffic accidents and maladaptive chronic fatigue. However, little is known about whether taking a nap or break immediately after a night shift improves fatigue recovery and sleep among nurses. This study aimed to examine the effects of taking a 30-min nap or break immediately after a 16-h night shift on fatigue recovery and sleep episodes among nurses.

Methods: A quasi-experimental crossover study was conducted with 62 nurses who worked 16-h night shifts. Nurses were randomly assigned to two condition sequences (AB or BA): (A) intervention (the nurses took a 30-min nap or break in a nap environment control system after a night shift) and (B) control (the nurses went home as usual after a night shift). Fatigue was measured immediately after the night shift, after taking a nap or break, and after getting up from nighttime sleep on the day after the night shift. Sleep episodes were assessed using a wearable device. Outcomes were compared between the two conditions.

Results: In the intervention condition, fatigue immediately after the night shift was significantly reduced by taking a nap or break, with a large effect size. Recovery from "local pain or dullness," one of the symptoms of work-related fatigue, was significantly higher in the intervention than control condition. Compared to the control condition, the intervention condition significantly delayed the timing of the first sleep episode, whereas no significant differences were observed in the main sleep parameters.

Conclusions: Taking a nap or break immediately after the night shift could be a countermeasure to address fatigue/sleep-related problems among nurses. For nursing managers, encouraging nurses to take a nap or break immediately after the night shift could be a viable option in comprehensive fatigue risk management. Therefore, appropriate napping environments should be installed in clinical settings.

Trial registration: UMIN000038444 (date of registration: 30 Oct 2019).