Taro Yamauchi

FTO polymorphisms in oceanic populations

AbstractIt has been suggested that Neels “thrifty genotype” model may account for high body weights in some Oceanic populations, which presumably arose in modern times. In European populations, common variants (rs1421085-C, rs17817449-G, and rs9939609-A) in the fat mass and obesity (FTO associated) were recently found to be associated with body mass index (BMI) or obesity. In this study, we investigated the population frequencies of these variants in six Oceanic populations (Melanesians, Micronesians, and Polynesians) and tested for an association with BMI. Unlike European populations, the Oceanic populations displayed no significant association between the FTO polymorphisms and BMI. These variants were in strong linkage disequilibrium. The population frequencies ranged between 4.2 and 30.3% in the six Oceanic populations, and were similar to those in southeast and east Asian populations. Our study of the FTO polymorphisms has generated no evidence to support the thrifty genotype hypothesis for Oceanic populations.

Factors associated with nutritional status in children aged 5-24 months in the Republic of Cameroon.

This study was conducted to clarify nutritional status and associated factors in 5-24 month old children in the district of Batouri, Republic of Cameroon. Mothers were interviewed using a semistructured questionnaire, and the childs weight, length, head circumference, and mid-upper arm circumference was collected. The data were compared with child growth standards proposed by the World Health Organization using Z-scores; χ(2) -test, Fishers exact test, and Wilcoxon rank sum test were used to determine variables associated with malnutrition. A total of 100 mother-child pairs participated in this study; valid data from 100 pairs were subjected to analysis. The percentages of children with malnutrition indicators were wasting (6%), stunting (31%), underweight (14%), and low mid-upper arm circumference (16%). Five factors were found to be statistically significant in their association with the childrens malnutrition: mothers age, childs age, mothers educational level, mothers who had family planning information, and the source of tap water. A high percentage of stunting was positively associated with a high percentage of chronic malnutrition. We speculate that insufficient nutrition was more likely to begin after weaning.

The serum leptin level and body mass index in Melanesian and Micronesian Solomon Islanders: Focus on genetic factors and urbanization

Objectives: This study examined the association between the serum leptin level and body mass index (BMI) and the effects of urbanization and polymorphisms of leptin (LEP) or leptin receptor (LEPR) genes on the leptin level in three Solomon Islands populations.

A missense variant, rs373863828-A (p.Arg457Gln), of CREBRF and body mass index in Oceanic populations

It has been suggested that a ‘thrifty’ genotype hypothesis can account for high prevalence of obesity in the island populations of Oceania. A recent genome-wide association study revealed that a missense variant, rs373863828-A (p.Arg457Gln), of the CREBRF gene (encoding CREB3 regulatory factor) was associated with an excessive increase in body mass index (BMI) in Samoans. In the present study, the association of rs373863828-A with an increase in BMI was examined in four Austronesian (AN)-speaking populations in Oceania. We found that rs373863828-A was frequently observed (frequency of 0.15) in Tongans (Polynesians), and was strongly associated with higher BMI (P=6.1 × 10−4). A single copy of the rs373863828-A allele increased BMI by 3.09 kg m−2 after adjustment of age and sex. No significant association was detected in the other three AN-speaking populations (Melanesians and Micronesians) living in Solomon Islands. This was probably due to the low allele frequency (0.02–0.06) of rs373863828-A as well as small sample size. The rs373863828-A allele was not found in both AN-speaking and non-AN-speaking Melanesians living in Papua New Guinea. Our results suggest that rs373863828-A of CREBRF, a promising thrifty variant, arose in recent ancestors of AN-speaking Polynesians.

Daily Physical Activity and Time-Space Using of Pygmy Hunter-Gatherers’ Children in Southeast Cameroon

Previous studies described the active daily lives and various daily behaviors for children of pygmy hunter-gatherers, however, there were only a few studies which reported daily physical activities and time-space using quantitatively for hunter-gatherers’ children. This study aimed to clarify following three topics for children of pygmy hunter-gatherers: (1) daily physical activities, (2) time-space use and (3) relationship between physical activities and time-space using. A field survey was conducted on 44 Baka children (28 boys and 16 girls) in a same village located southeast Cameroon. GPS log tracks were obtained from all 44 children, and acceleration monitoring were performed for 21 children each for consecutive 3 days. Baka children showed a generally high level of physical activity. They walked more than 20,000 steps per day (boys: 25,331 ± 9,348, girls: 22,400 ± 4,258), and the mean of their estimated PALs (boys: 2.08 ± 0.21, girls: 2.10 ± 0.15) were classified “vigorous.” Total travel distances and active radii were become significantly greater as their age increased, and a dispersion was appeared in older boys. The sex-/age- difference for daily time-space using were observed from GPS log data, moreover, it was considered that boys changed their daily lives greater than girls as they grew up. In addition, it was suggested that activities outside of their own village were related to increasing children’s physical activities.

Time allocation to subsistence activities among the Huli in rural and urban Papua New Guinea.

Time spent on subsistence activities was compared between rural sedentes and urban migrants of the Huli population in Papua New Guinea. Person-day observation data were collected for rural sedentes (441) in the Tari basin and for urban migrants in Port Moresby (175). The time spent on subsistence activities by males was longer in the urban area than in rural areas, while that by females was similar in both areas. Conspicuous gender inequality with respect to labour hours in rural areas seems to diminish when people move to urban areas, reflecting the different subsistence regime between rural and urban environments.

The Flow State Scale for Occupational Tasks: Development, Reliability, and Validity

Objective/Background The degree of a patients absorption in tasks as a measure of rehabilitation effectiveness has yet to be studied. The objective of this study is to develop a scale that can measure a patients flow state in a clinical situation such as occupational therapy (OT). Methods The final 14 items were determined from the comprehensive assessment of item analysis results by a preliminary experiment. A total of 240 participants engaged in computer games that induced three psychological states: flow, anxiety, and boredom. After performing each task, participants completed our flow scale and the State-Trait Anxiety Inventory (STAI). The reliability was calculated using Cronbachs alpha coefficient. The validity was confirmed from three viewpoints, namely, the correlation coefficient with the STAI, the discrimination power of each psychological state, and the accuracy of factor structure. An occupational analysis of various activities was also conducted to confirm that the computer game task was representative of measurable activities. Results Cronbachs alpha coefficient was .918. The total score of the scale was significantly negatively correlated with the total score of STAI (r = -.537, p < .01). A significant difference among each psychological state was observed (p < .01). Covariance structure analysis indicated that the model fit index showed an acceptable fit. The computer game task used in this experiment was closely related to games, crafts, learning, cooking, and playing an instrument. Conclusion Our flow scale appears to have satisfactory reliability and validity to verify quantitatively whether the occupational tasks used in OT can effectively provide a flow experience for patients.

Adolescent growth spurt and growth pattern factors related to the short stature of Pygmy hunter-gatherers of Southeast Cameroon

Introduction: Many studies have been carried out to reveal the mechanism of the short stature of Pygmy hunter-gatherers in the African rainforest. However, due to limitations concerning age-estimation, sample collecting and data analysis, their complete growth pattern has not yet been clarified. Aims: This study has three aims as below; (1) to develop a smoothed growth curve, (2) to elucidate the presence of adolescent growth spurt and (3) to assess the correlation of growth pattern factors to their final short stature. Subjects and methods: Anthropometric measurements including height and weight were carried out for 626 Baka children in southeast Cameroon. LMS method and Preece-Baines function were adopted to develop a smoothed growth curve and to assess their growth pattern. Results: The height velocity curve and acceleration curve derived from the LMS method showed the presence of an adolescent growth spurt. Biological parameters indicated their spurt was extremely weak and started at nearly the same time as published populations. Height gains between take-off and final height were almost equal between Baka children and children in published populations. Conclusion: The presence of a weak adolescent growth spurt is suggested in the growth pattern of Pygmy hunter-gatherers. Moreover, their short adult stature is possibly related to growth rate before onset of puberty.

High Motivation and Low Gain: Food Procurement from Rainforest Foraging by Baka Hunter-Gatherer Children

In this paper, we described the daily activities of Pygmy hunter-gatherer children living in a foraging forest camp. Our two aims were (1) to clarify their time use and participation in food procurement activities and (2) to evaluate their contribution to food acquisition. The authors accompanied the children on an 8-day hunt and conducted direct observations on six children, focusing on one of them each day (12 h; 06:00–18:00). All foods brought back to the camp were identified and weighed, and their energy and protein values were calculated. Children were considered to be generally physically active, and they participated in food procurement activities about 3 h in a day, which was nearly the same amount of time as the Baka adults spent on those activities. Boys mainly spent their time rat hunting (101.7 min), while girls spent more time bail fishing (120.3 min) than rat hunting (60.0 min). Although the children spent more time foraging and had a greater number of participants engaged in it, the total amount of game that adults obtained was much greater (2787 g obtained by children and 12,273 g by adults). Each game brought back by adults (e.g., tortoises or vipers) was also generally heavier than that of children (e.g., rats or galago). Children often move in groups of four to eight people and perform most food acquisition activities with at least three to four people. Regarding the transition of their activity patterns as they got older, we hypothesized that boys tend to act alone or in smaller units, whereas girls continue to act in groups that contain people of various ages.

Estimation of the Period of Childhood and Child Growth Characteristics of Pygmy Hunter-Gatherers in Southeast Cameroon

Data on the growth pattern of pygmy hunter-gatherers may provide key knowledge about the mechanism of human evolution. However, only few studies have compared their growth pattern with those of modern human populations. This study aims at characterizing the growth pattern of pygmy hunter-gatherers by using a mathematical method and comparing their pattern with that of other worldwide populations. Height and weight of 626 Baka children in southeast Cameroon were measured. The nutritional status was assessed using body mass index (BMI), and the Preece-Baines function was adopted for obtaining height velocity curve and assessing growth pattern. More than 80 % participants had BMI in the normal range, and their nutritional status was considered generally good. The height velocity curves and biological parameters indicated that their adolescent growth spurts were very week. However, the periods of adolescent growth spurt of Baka children were almost similar to those of previously studied five groups. Furthermore, their growth rate during the early childhood was suggested to be very slow. The periods of childhood were the same among the modern human populations. However, a great difference was observed in the linear growth rate between the Baka and other populations.