Urban–rural contrasts in the physical fitness of school children in Oaxaca,Mexico

The physical fitness of school children resident in an urban colonia and in a rural indigenous community in Oaxaca, southern Mexico, was compared. Two measures of performance‐related fitness (standing long jump, 35‐yard dash [32 m]) and four measures of health‐related fitness (grip strength, sit and reach, timed sit‐ups, distance run) were taken on 355 rural (175 boys, 184 girls) and 324 urban (163 boys, 161 girls) school children, 6–13 years of age. Urban children were significantly taller and heavier than rural children. Absolute grip strength did not consistently differ between rural and urban children, but when adjusted for age and body size, strength was greater in rural children. Explosive power (standing long jump) and abdominal strength and endurance (timed sit‐ups) were better in urban than in rural children without and with adjustment for age and body size. Urban–rural differences in running speed (dash) and flexibility (sit and reach) varied by age group and sex. Younger rural children and older urban girls performed better in the distance run, whereas older rural and urban boys did not differ in endurance. The size advantage of urban children does not necessarily translate into better levels of performance‐ and health‐related physical fitness. The observed differences may be related to activity habits associated with school physical education and lifestyle in the respective communities. Am. J. Hum. Biol. 15:800–813, 2003. © 2003 Wiley‐Liss, Inc.     

Gender differences in the learning status of diabetic children.

The learning status of 95 diabetic boys and girls and 97 matched controls was evaluated using the Wechsler Intelligence Scale for Children--Revised IQ factors and school histories. Of interest was whether diabetic boys would evidence more learning difficulties. Results indicated that diabetic boys had significantly lower Freedom From Distractibility scores compared with scores of diabetic girls and control Ss and lower Perceptual Organization scores compared with scores of control boys. Although group scores were still within the average range of functioning, a significantly high percentage of diabetic boys (40%) compared with diabetic girls (16%) had learning problems that warranted either special instructional services or grade retention. Diabetic children experienced more learning difficulties (24%) than controls (13%), supporting research findings that diabetes is associated with increased risk of learning problems.     

Nutritional status of institutionalized Venezuelan elderly

With the aim of evaluating the nutritional status of institutionalized elders in different geriatric units of the metropolitan area of Caracas, 126 subjects with ages between 60 and 96 years old were evaluated. The Mini Nutritional Assessment was applied and were identified 48.4% individuals with nutritional risk, 5.6% malnourished and 46% without nutritional problems. Females presented higher prevalences of malnutrition and risk, while males presented an adequate nutritional state. By sex and age, females and males over 80 years presented a higher prevalence of malnutrition and risk when they were compared whit those younger. A low dayly liquid intake, a BMI equal or under of 23 kg/m2 and a limited physical performance were the items that presented the highest prevalence among the studied elders. In conclusion, the high prevalence of malnutrition risk in this population group, remarks the necessity to include into the global geriatric evaluation, a quick, simple and non-invasive instrument that allows to estimate the nutritional status of the elders.     

Urban-rural differences in the growth of South African black children.

Urbanization is a major migratory process characteristic of developing countries. The majority of comparisons of the growth of urban and rural children from developed countries reflect greater heights and weights, and by implication health, of urban children. Urban-rural comparisons of South African black children are few in number and have concentrated on 'average' children, thereby omitting the factor of socioeconomic status. The present study compares two groups of urban children of high (n = 307) and average (n = 867) socioeconomic status and two groups of rural children. The rural children came from farm labourer's families (n = 392) and traditional subsistence farming environments (n = 420). The children ranged in age from 5 to 19 years. In general the well-off urban children were consistently, but not significantly, larger than all other groups and 'average' urban children were consistently and at times significantly smaller and lighter. The growth of the two rural groups fell between these extremes but were also consistently different in that the children of farm labourers were significantly lighter at all ages than children living in a traditional subsistence economy. It is concluded that the average urban environment in South Africa is not conducive to improved growth and health unless it is accompanied by an improved socioeconomic status.     

Socioeconomic variation in the growth status of urban school children 6–13 years in Oaxaca,Mexico, in 1972 and 2000

Socioeconomic variation in the growth status of urban school children 6–13 years of age in 1972 and 2000 was compared. The children were resident in the city of Oaxaca and were students in the same primary school in each year. Socioeconomic status (SES) was based on parental occupation. Height, sitting height, estimated leg length, weight, and the body mass index in 218 boys and 191 girls in 1972 and 173 boys and 166 girls in 2000 were compared. Sex‐specific MANCOVA was used to evaluate SES differences within each year, while sex‐ and SES‐specific MANCOVA was used to evaluate differences between years. The prevalence of stunting, overweight and obesity was estimated. There were no SES differences among boys and girls in 1972 and boys in 2000; low‐middle and middle SES girls were significantly taller and heavier with longer legs than low SES girls in 2000. Within each SES group, children in 2000 were significantly larger in body size and segment lengths except for sitting height in low SES children of both sexes. Estimated secular gains increased from low to low‐middle to middle SES in both sexes. Inequitable gains by SES contributed to an increase in the magnitude of differences between SES groups, especially between low SES children on one hand and low‐middle and middle SES children on the other hand. The prevalence of stunting declined while the prevalence of overweight and to a lesser extent in obesity increased from 1972 to 2000, more so in low‐middle and middle SES than in low SES children. Am. J. Hum. Biol. 2009. © 2009 Wiley‐Liss, Inc.     

Nutritional status among rural Meitei children of Manipur,India

The nutritional status of 301 rural Meitei children (5–11 years old, 163 boys and 138 girls) from low socioeconomic backgrounds was evaluated with the help of dietary survey, clinical signs of mineral and vitamin deficiencies, and selected anthropometric dimensions. The diet was cereal and starchy food—based with rice forming the staple food. Potatoes and green grams, were the commonly consumed tubers and pulses, respectively. Consumption of fruits, eggs, milk, and milk products was extremely low. Vitamin A and C deficiencies were the most common. Spongy bleeding gums (19%), and Bitot's spot (11%) and conjunctival xerosis (12%) were the most prevalent clinical signs of vitamin C and A deficiency, respectively. Compared to girls, boys had a significantly higher incidence of deficiency signs. Mean statures and weights are below the 20th percentile of U.S. (NCHS) reference data. The incidence of stunting was substantially more than that of wasting. Nearly 29% of the children had z-scores 2 S.D. or more below the NCHS median in stature-for-age. Only 1.7% of the children had z-scores 2 S.D. or more below the reference median of weight-for-stature. More girls than boys were classified as having normal weight/age, stature/age, and weight/stature. The results are contrary to the common belief that Indian girls are at a nutritional disadvantage compared to boys. Rather, the findings support the concept of better buffering of female than males under conditions of environmental stress. © 1994 Wiley-Liss, Inc.     

Arterio‐venous differences of blood acid–base status and plasma sodium caused by intense bicycling

After intense exercise muscle may give off hydrogen ions independently of lactate, perhaps by a mechanism involving sodium ions. To examine this possibility further five healthy young men cycled for 2 min to exhaustion. Blood was drawn from catheters in the femoral artery and vein during exercise and at 1‐h intervals after exercise. The blood samples were analysed for pH, blood gases, lactate, haemoglobin, and plasma proteins and electrolytes. Base deficit was calculated directly without using common approximations. The leg blood flow was also measured, thus allowing calculations of the leg’s exchange of metabolites. The arterial blood lactate concentration rose to 14.2 ± 1.0 mmol L^–1, the plasma pH fell to 7.18 ± 0.02, and the base deficit rose 22% more than the blood lactate concentration did. The femoral‐venous minus arterial differences peaked at 1.8 ± 0.2 mmol L^–1 (lactate), –0.24 ± 0.01 (pH), and 4.5 ± 0.4 mmol L^–1 (base deficit), and –2.5 ± 0.7 mmol L^–1 (plasma sodium concentration corrected for volume changes). Thus, near the end of the exercise and for the first 10 min of the recovery period the leg gave off more hydrogen ions than lactate ions to the blood, and sodium left plasma in proportion to the extra hydrogen ions appearing. The leg’s integrated excess release of hydrogen ions of 0.88 ± 0.45 mmol kg^–1 body mass was 67% of the integrated lactate release. Base deficit calculated by the traditional approximate equations underestimated the true value, but the error was less than 10%. We conclude that intense exercise and lactic acidosis may lead to a muscle release of hydrogen ions independent of lactate release, possibly by a Na⁺,H⁺ exchange. Hydrogen ions were largely buffered in the red blood cells.     

Patterns of childhood mortality and growth status in a rural Zapotec community

Infant and childhood mortality (birth to 14 years), and growth status of 143 schoolchildren (5 to 14 years) are considered for a rural, Zapotec-speaking community (population, 1703) in the Valley of Oaxaca, Mexico. Mortality statistics are based on civil records from 1945 to 1970. Growth status is based on weight and height for age, and weight for height. In the Zapotec community, about 59% of all deaths occur in children under 15 years of age; thus, a considerable percentage of individuals die before reaching reproductive age. Children under 5 years of age, however, account for approximately 54% of all deaths, and mortality in children 1 to 4 years of age is especially high (27% of all deaths). The latter figure suggests chronic malnutrition, frequent disease and generally poor circumstances in the community. This suggestion is supported in the heights and weights of schoolchildren, survivors of the rigorous selection processes of the pre-school years. The majority of children are below the 5th centile for stature in well-nourished American children. Weight for height, however, approximates that of the USA reference data.     

Gender differences in growth and nutrition in a sample of rural Ontario schoolchildren.

This paper reports findings of a cross-sectional study of the growth and nutrition of children living in rural Ontario, Canada. The objectives of the research were threefold: (1) to obtain data on obesity prevalence and nutrient intake in a sample of rural Canadian schoolchildren, (2) to compare findings with rural and national-level data on obesity prevalence and nutrient intake, and (3) to provide data to school board and public health agencies planning and implementing nutrition policy and programs to this population. Measures of height and weight were obtained for 504 children ages 7-13 years. Height for age and body mass index scores were calculated and compared with 2000 data from the Centers for Disease Control (Kuczmarski et al. [2002]: Vital Health Stat 246:1-190). Weekday 24-h dietary recall was conducted on a subsample of 352 children and the results compared with Canada's Food Guide (Health Canada,1997) and dietary reference data from the US Institute of Medicine (2000). Prevalence of overweight and obesity were high in this sample, with 17.7% of children classified as overweight and 10.9% of children classified as obese. Fifteen percent of boys were classified as obese, compared to 6.8% of girls. Boys consumed significantly more servings from the grain and meat food groups than girls. While mean daily intake of fiber and micronutrients was significantly low for both boys and girls, there were significant gender differences in nutrient intake, with boys consuming greater energy, protein, carbohydrate, calcium, iron, phosphorus, and sodium than girls. A number of limitations are discussed, in particular issues arising from the use of Dietary Reference Intakes.     

Blood lead levels and growth status of children

Several studies have shown that elevated blood lead (Pb) levels in children are associated with decreased growth. Among 139 children aged 1 to 10 years (66 male, 73 female) who attended a Pb clinic in Dallas, Texas, growth was decreased by 1.6 cm in height, 1.4 kg in weight, and 0.6 cm in head circumference for each 10 μg/dl increase in blood Pb. Consistent with previously reported effects of Pb, several clinical symptoms (hearing deficit, dental problems, hyperactivity) were increased in frequency among children with high blood Pb levels (X?_Pb = 34.6 μg/dl ± 5.6) compared to the children in the low Pb level group (X?_Pb = 11.9 μg/dl ± 3.3). Interestingly, pica was significantly increased in frequency among children in the high Pb group, indicating oral consumption of non-food matter was a major source of Pb intoxication. These results suggest that increased Pb level is an important risk factor for growth deficits in children.     

Growth status of children in rural Mali: Implications for nutrition education programs

In conjunction with a rural development project, a cross-sectional anthropometric survey and ethnographic research were conducted in six rural villages in southern Mali where food is generally sufficient. A total of 1,132 individuals were measured, and individual and group interviews concerning dietary habits and intra-familial food distribution patterns were conducted. In this paper, data on the growth status of children under 12 years of age (N=575) are reported and analyzed. As defined by inadequate growth, rates of malnutrition are extremely high in this population. Deficits in growth peak among the 2 year olds, with 67% falling more than 2 SD below the NCHS/WHO standard for weight-for-age, and 53% falling more than 2SD below the standard for height-for-age. Deficits in weight-for-height are highest among the 1 year olds, with 32% falling more than 2 SD below the NCHS/WHO standards. From birth to 23 months, the correlation between age (in months) and weight-for-age z-scores is ?.63 (P=.0001). Between 24 and 47 months, the correlation improves, to +.36 (P=.0004), indicating that children experience some catch-up growth. By the age of 11 years, they still have not recovered fully from the combination of poor nutrition and infections in early childhood, however, and malnutrition continues to be a problem throughout childhood. Iodine deficiency is also a problem in two of the six villages. Interview data confirm earlier findings in Mali regarding child feeding practices, specifically, that infants and young children are expected to feed themselves, and that the best foods are reserved for adults. These findings have important implications for the design and implementation of nutrition education programs in southern Mali.     

Sex differences in the genetic architecture of obsessive–compulsive disorder

Obsessive–compulsive disorder (OCD) is a highly heritable complex phenotype that demonstrates sex differences in age of onset and clinical presentation, suggesting a possible sex difference in underlying genetic architecture. We present the first genome‐wide characterization of the sex‐specific genetic architecture of OCD, utilizing the largest set of OCD cases and controls available from the Psychiatric Genomics Consortium. We assessed evidence for several mechanisms that may contribute to sex differences including a sex‐dependent liability threshold, the presence of individual sex‐specific risk variants on the autosomes and the X chromosome, and sex‐specific pleiotropic effects. Furthermore, we tested the hypothesis that genetic heterogeneity between the sexes may obscure associations in a sex‐combined genome‐wide association study. We observed a strong genetic correlation between male and female OCD and no evidence for a sex‐dependent liability threshold model, suggesting that sex‐combined analysis does not suffer from widespread loss of power because of genetic heterogeneity between the sexes. While we did not detect any significant sex‐specific genome‐wide single nucleotide polymorphisms (SNP) associations, we did identify two significant gene‐based associations in females: GRID2 and GRP135, which showed no association in males. We observed that the SNPs with sexually differentiated effects showed an enrichment of regulatory variants influencing expression of genes in brain and immune tissues. These findings suggest that future studies with larger sample sizes hold great promise for the identification of sex‐specific genetic risk factors for OCD.     

Urban-rural contrasts in the growth status of school children in Oaxaca, Mexico

OBJECTIVES: The growth status of school children resident in an urban colonia and in a rural indigenous community in Oaxaca, southern Mexico, was considered in the context of two objectives, current status and the magnitude of urban-rural differences over a span of about 30 years. Both communities were initially surveyed in 1968 and 1972. MATERIALS AND METHODS: Height, body mass, segment lengths, skeletal breadths, limb circumferences, and subcutaneous fatness were taken on 361 rural (177 boys, 184 girls) and 339 urban (173 boys, 166 girls) school children, aged 6-13 years. Additional variables were derived. RESULTS: Height and body mass were significantly greater in urban compared with rural children. Sitting height, estimated leg length and skeletal breadths on the trunk were also larger in urban than in rural school children, but only the difference in skeletal breadths was significant after age and body size were statistically controlled. Urban and rural children did not consistently differ in skeletal breadths on the extremities and limb circumferences. Subcutaneous fatness was more variable. After controlling for age and body size, rural girls had thicker skinfolds. The magnitude of the urban-rural difference in boys in 2000 was greater for body mass, BMI and triceps skinfold, and reduced for height, sitting height, leg length, and arm and estimated arm muscle circumferences compared with 1970. The magnitude of the urban-rural difference in girls was greater in 2000 than 30 years earlier for body mass, height, sitting height, leg length and BMI. Urban-rural differences for arm and arm muscle circumferences and the triceps skinfold were slightly smaller over the interval. CONCLUSIONS: Children resident in an urban colonia were taller and heavier than children resident in a rural indigenous community. After controlling for age and body size, urban-rural differences in skeletal breadths and limb circumferences were reduced or eliminated, but skinfold thicknesses were greater in rural girls. The magnitude of urban-rural differences in body size has decreased over approximately 30 years in boys, but has increased in girls.     

Fat distribution in relation to sex and socioeconomic status in children 4–19 years

Fat distribution was studied in an urban sample of boys and girls 4.5 to 19.5 years from the Basque province of Biscay by means of Principal Component Analysis (PCA) of five skinfolds. The PCA extracted four components, which explained 99.1% of the total variance. The first principal component revealed strong stability across age and sex, and was related to a pattern of central body fat distribution. The three other components, upper-lower trunk fat, lateral-medial trunk fat, and upper-lower extremity fat, showed poor stability due largely to the influence of age and, to a lesser degree, sex. In both sexes, individual scores of the four factors did not show multivariate differences by socioeconomic status when a MANOVA with age, age² and age³ as covariates was done. Nevertheless, the first factor scores were significantly higher only in the poorer socioeconomic group of girls. The results are explained in the context of either different lifestyles related to socioeconomic status, a protective effect against environmental stress on urban males, or greater plasticity of trunk fat relative to extremity fat in females. Am. J. Hum. Biol. 10:799–806, 1998. © 1998 Wiley-Liss, Inc.     

Using the WHO 2006 child growth standard to assess the growth and nutritional status of rural south Indian infants

Background: The WHO 2006 child growth standard is advocated in India, although the conformity of the growth of Indian infants to the WHO standard has only been assessed at cross-sectional points.

Aim: To assess the implications of using the WHO standard in rural India and to investigate the factors responsible for any departure from optimal growth, as shown in the WHO standard.

Subjects and methods: Mixed-effects models were applied to serial weight and length data from 384 rural south Indian infants. Unadjusted and adjusted (for, among other things, breastfeeding and maternal education) estimates were converted to Z-scores and the risks of underweight, wasting and stunting using the WHO standard compared to the NCHS 1977 child growth reference were calculated.

Results: Weight growth was more similar to the WHO standard than the NCHS reference and in late infancy the WHO standard was less likely to classify underweight (RR at 15 months = 0.45; 95% CI = 0.31–0.65). Adjusting the serial data shifted the curves 0.25 Z-scores closer to the median of either chart; variations in household socioeconomic status and morbidity were largely responsible for this shift.

Conclusion: In late infancy, the WHO standard will allow a more focused intervention effort and use of resources for targeting programmes at infants most at risk of malnutrition.