How useful is BMI in predicting adiposity indicators in a sample of Maya children and women with high levels of stunting?

Sports activity and changes in physical fitness of Polish children and adolescents: OSF study

BACKGROUND

Physical activity promotion programs for children and adolescents should constitute the basis of any national health policy aiming to improve physical fitness, which is a significant health indicator in children, adolescents, adults as well as elderly persons.

METHODS

The study included 1,230 children and adolescents aged 8-16 years (60.1% of girls) from Poland. Five hundred and twenty-seven persons covered by the survey (42.8%) participated in physical activity promotion called "Athletics for All!" (AFA) as an experimental group and 703 peers not participating in any forms of physical extra-curricular activities as a control group. Participants were measured for basic anthropometric parameters and body mass indices were calculated: Body Mass Index (BMI) and Ponderal Index (PI). Evaluation of physical fitness was made using the OSF Test (3 × 10 m shuttle run, standing broad jump, 1 kg medicine ball overhead throw, 4-min run). Comparative analysis between the experimental and control groups was carried out using the T-test for independent samples. Analysis of correlations between quantitative variables was performed with Pearson's r coefficient.

RESULTS

Statistically significant differences in all the tests were noted between the experimental group (AFA) and the control group in favor of the former one. Taking into account reference ranges of BMI created according to the latest Polish norms, statistically significant differences were noted between the subgroups in all physical fitness tests. As far as PI is concerned, in the AFA group significant differences were noted in all physical fitness tests between subgroups created in accordance with the aforementioned norms.

CONCLUSION

The findings of our study show that it is necessary to introduce physical activity promotion programs for children and adolescents. Such programs should constitute the basis of national health policy aiming at improving physical fitness among young people.

Associations between anthropometric indicators of adiposity and body fat percentage in normal weight young adults

The purpose of this cross-sectional study was to determine the associations between various anthropometric adiposity screening indices and body fat percentage estimated by bioelectrical impedance analysis (BIA). A total of 186 (95 male and 91 female) normal weight (body mass index [BMI] = 18.5- 24.9 kg/m2) young adults (mean age= 20.96 ± 2.03 years) were measured on body fat percentage, body height, body mass, waist and hip circumferences. Abdominal volume index, body adiposity index, BMI, body roundness index, conicity index, reciprocal ponderal index, waist to height ratio, waist to height 0.5 ratio, and waist to hip ratio were calculated accordingly. Results revealed significant gender effects in all main anthropometric measurements. Except for waist to hip ratio, results indicated significant associations between anthropometric indices and BIA in both male and female participants. BIA results were found to be largely associated with BMI and abdominal volume index in both genders. Bland- Altman analysis showed good agreements between these indices and BIA. Considerable associations and agreements highlight the potential importance and the use of several anthropometric proxies to estimate body adiposity among male and female non-overweight/obese young adults. Despite continuing discussion regarding its accuracy, BMI seems to be useful for monitoring body adiposity within this cohort.

Preece-Baines Model 1 to Estimate Height and Knee Height Growth in Boys and Girls From Merida, Mexico

Background:

Height and body segments in children have differential pubertal growth characteristics. Lower leg length is a sensitive indicator of child’s nutritional status.

Objective:

The purpose of this study was to estimate differential timing and tempo of height and knee height (KH) growth in 9- to 17-year-old boys (n = 475) and girls (n = 500) from Merida, Mexico.

Methods:

In this cross-sectional study, the Preece-Baines growth curves—model 1 (PB 1) was fitted to the anthropometric data for height and KH.

Results:

Based on the PB 1 model, KH had earlier age at maximum increment than height in boys (height = 12.37 years, KH = 11.54 years) and girls (height = 11.01 years, KH = 10.93 years). Peak velocity of these 2 dimensions was different in both sexes (boys: height = 7.11 cm/yr, KH = 2.25 cm/yr; girls: height = 5.14 cm/yr, KH = 1.45 cm/yr). Differences ( P <.001) by sex were also observed for the estimated size at peak velocity and final size of height and KH.

Conclusions:

When compared to height, KH was shown to have earlier adolescent growth spurt and a smaller difference between final size and the size at maximum (peak) velocity indicating an earlier age for achieving adult size. Overall, the studied boys and girls had short estimated final size, an earlier age at maximum increment, and a lower peak velocity in height than urban Guatemalan peers, the only regional reference available.

Surname-inferred Andean ancestry is associated with child stature and limb lengths at high altitude in Peru, but not at sea level

OBJECTIVES

Native Andean ancestry gives partial protection from reduced birthweight at high altitude in the Andes compared with European ancestry. Whether Andean ancestry is also associated with body proportions and greater postnatal body size at altitude is unknown. Therefore, we tested whether a greater proportion of Andean ancestry is associated with stature and body proportions among Peruvian children at high and low altitude.

METHODS

Height, head circumference, head-trunk height, upper and lower limb lengths, and tibia, ulna, hand and foot lengths, were measured in 133 highland and 169 lowland children aged 6 months to 8.5 years. For highland and lowland groups separately, age-sex-adjusted anthropometry z scores were regressed on the number of indigenous parental surnames as a proxy for Andean ancestry, adjusting for potential confounders (maternal age and education, parity, altitude [highlands only]).

RESULTS

Among highland children, greater Andean ancestry was negatively associated with stature and tibia, ulna, and lower limb lengths, independent of negative associations with greater altitude for these measurements. Relationships were strongest for tibia length: each additional Andean surname or 1,000 m increase at altitude among highland children was associated with 0.18 and 0.65 z score decreases in tibia length, respectively. Anthropometry was not significantly associated with ancestry among lowland children.

CONCLUSIONS

Greater Andean ancestry is associated with shorter stature and limb measurements at high but not low altitude. Gene-environment interactions between high altitude and Andean ancestry may exacerbate the trade-off between chest dimensions and stature that was proposed previously, though we could not test this directly.

Correlates of objectively measured overweight/obesity and physical activity in Kenyan school children: results from ISCOLE-Kenya

BACKGROUND

Childhood overweight/obesity and inadequate physical activity burden Western countries, and now, pose a growing threat to the health of children in low and middle income countries. Behavioural transitions toward more sedentary lifestyles coupled with increased consumption of high calorie foods has resulted in rising proportions of overweight/obesity and decreasing levels of physical activity in school-aged children. The objective of this study was to determine the prevalence and to investigate factors associated with overweight/obesity and physical activity in Kenyan children aged 9 to 11 years.

METHODS

Body composition and physical activity measures of participating children were accomplished by anthropometric assessment, accelerometry, and administration of questionnaires related to diet and lifestyle, and the school and neighbourhood environments. Data collection was conducted in the city of Nairobi as part of a larger International Study of Childhood Obesity, Lifestyle and Environment.

RESULTS

A total of 563 participants (46.5% boys, 53.5% girls) were included in the analyses. Of these, 3.7% were underweight, 14.4% were overweight, and 6.4% were obese based on WHO cut-points. Mean daily sedentary time was 398 minutes, time spent in light physical activity was 463 minutes, and time spent in moderate-to-vigorous physical activity was 36 minutes based on activity cut-points developed by Treuth et al. Only 12.6% of participating children were meeting the recommendation of ≥ 60 minutes of daily moderate-to-vigorous physical activity, and 45.7% of participants used active transportation to/from school. Increasing parental education level, total annual household income, and attending a private rather than public school were associated positively with being overweight/obese and negatively with meeting physical activity guidelines.

CONCLUSIONS

This study provided the evidence for an existing prevalence of childhood overweight/obesity in Nairobi. Children were spending a considerable amount of time in sedentary and light intensity physical activity, with few meeting physical activity guidelines. Higher socioeconomic status and parental education attainment were associated with a higher likelihood of children being overweight/obese and a lower likelihood of children meeting the physical activity recommendations. Interventions and strategies should be attentive to the potential health consequences of lifestyle transitions resulting from urbanisation and economic prosperity.

Stunting, adiposity, and the individual-level "dual burden" among urban lowland and rural highland Peruvian children

Background

The causes of the “dual burden” of stunting and obesity remain unclear, and its existence at the individual level varies between populations. We investigate whether the individual dual burden differentially affects low socioeconomic status Peruvian children from contrasting environments (urban lowlands and rural highlands), and whether tibia length can discount the possible autocorrelation between adiposity proxies and height due to height measurement error.

Methods

Stature, tibia length, weight, and waist circumference were measured in children aged 3–8.5 years (n = 201). Height and body mass index (BMI) z scores were calculated using international reference data. Age-sex-specific centile curves were also calculated for height, BMI, and tibia length. Adiposity proxies (BMI z score, waist circumference-height ratio (WCHtR)) were regressed on height and also on tibia length z scores.

Results

Regression model interaction terms between site (highland vs. lowland) and height indicate that relationships between adiposity and linear growth measures differed significantly between samples (P < 0.001). Height was positively associated with BMI among urban lowland children, and more weakly with WCHtR. Among rural highland children, height was negatively associated with WCHtR but unrelated to BMI. Similar results using tibia length rather than stature indicate that stature measurement error was not a major concern.

Conclusions

Lowland and rural highland children differ in their patterns of stunting, BMI, and WCHtR. These contrasts likely reflect environmental differences and overall environmental stress exposure. Tibia length or knee height can be used to assess the influence of measurement error in height on the relationship between stature and BMI or WCHtR.

Body fatness in relation to physical activity and selected socioeconomic parameters of adolescents aged 15-17 years in Merida, Yucatan

BACKGROUND

Increasing rates of overweight and obesity in adolescents are major concerns in many countries, including Mexico.

OBJECTIVES

To study anthropometric and body composition characteristics (BCC) and their relations with socioeconomic status (SES), biological history and physical activity (PA) of school-going adolescent boys and girls in the city of Merida, Yucatan, Mexico.

SUBJECTS AND METHODS

In this cross-sectional study, a sample of 321 adolescents (156 boys and 165 girls) aged 15-17 years from public and private schools in Merida, was taken from a study carried out in 2008-2009.

RESULTS

Body mass index had significant correlations to BCC (fat mass and fat-free mass). The rate of stunting was higher in girls (18.20%) than in boys (7.69%). Stunted adolescents had higher body fat (%) than normally growing peers. High rates of overweight (boys 26.28%, girls 24.24%) and obesity (boys 10.26%, girls 6.06%) were recorded. SES (parents' age, education and occupation; crowding index in the family; household food expenditure), participants' biological history and PA are related with height and BCC by age and sex.

CONCLUSION

Adolescents with excess weight (overweight + obesity) reported being less physically active. SES and PA were strongly related to growth and body fatness in the studied adolescents.

Brief communication: Body mass index, body adiposity index, and percent body fat in Asians

Human obesity is a growing epidemic throughout the world. Body mass index (BMI) is commonly used as a good indicator of obesity. Body adiposity index (BAI = hip circumference (cm)/stature (m)(1.5) - 18), as a new surrogate measure, has been proposed recently as an alternative to BMI. This study, for the first time, compares BMI and BAI for predicting percent body fat (PBF; estimated from skinfolds) in a sample of 302 Buryat adults (148 men and 154 women) living in China. The BMI and BAI were strongly correlated with PBF in both men and women. The correlation coefficient between BMI and PBF was higher than that between BAI and PBF for both sexes. For the linear regression analysis, BMI better predicted PBF in both men and women; the variation around the regression lines for each sex was greater for BAI comparisons. For the receiver operating characteristic (ROC) analysis, the area under the ROC curve for BMI was higher than that for BAI for each sex, which suggests that the discriminatory capacity of the BMI is higher than the one of BAI. Taken together, we conclude that BMI is a more reliable indicator of PBF derived from skinfold thickness in adult Buryats.

Nutritional status of Maya children, their mothers, and their grandmothers residing in the City of Merida, Mexico: revisiting the leg-length hypothesis

OBJECTIVES

To test the hypothesis that leg length-relative-to-stature is a more sensitive indicator of nutrition and health than is total height (HT) or sitting height (SH) in a sample of 109 triads of urban Maya children (6.0-8.99 years), their mothers, and maternal grandmothers from Merida, Mexico.

METHODS

From September 2011 to June 2012, the following factors were obtained from all participants: (1) HT, SH, and leg length (LL); (2) the sitting height ratio (SHR = [SH × 100]/HT), relative leg length index (RLLI = [LL × 100]/height), and percentiles and z-scores of HT, SH, and LL were calculated; and (3) the percentages of stunting for children or very short ZHT for the adults, short ZSH, and short ZLL: HT-for-age, SH-for-age, or LL-for-age below the 5th percentile of the reference were calculated. Correlations were performed to examine the association between z-scores of HT, SH, and LL among three generations.

RESULTS

Stunting in children was 11% (short ZLL = 29%, short ZSH = 7%). Short ZHT was present in 71% of mothers (short ZLL = 54%, short ZSH = 50%) and 90% of grandmothers (short ZLL = 69%, short ZSH = 83%). Significant correlations in ZHT, ZSH, and ZLL were found in mother-to-child and grandmother-to-mother, with the strongest correlations for ZLL.

CONCLUSIONS

These findings support the hypothesis for children and mothers. Based on ZLL, there is evidence that childhood and nutrition have improved somewhat for each younger generation. Persistent environmental adversity during growth resulted in growth deficits for LL and SH for the mothers and grandmothers.

Health and adult productivity: the relation between adult nutrition, helminths, and agricultural, hunting, and fishing yields in the Bolivian Amazon

OBJECTIVES

Infectious disease and nutritional stress have both been associated with reductions in adult work productivity and work capacity in the context of wage labor, but less research has investigated their effects among groups relying on more traditional subsistence practices of horticulture and foraging. In this article, we examine the relations among measures of adult nutritional status (BMI, skinfold measurements, and fat-free mass) and infection (presence of soil transmitted helminth infections) and measures of adult work productivity.

METHODS

As part of a larger panel study among Tsimane', a foraging-horticulturalist group in the Bolivian Amazon, health surveys, anthropometric information, and the quantity of products (both crops and game) brought into the household were collected for 320 Tsimane' adults over a four-month period in 2003. In addition, a single fecal sample was collected for a sub-sample of 86 adults.

RESULTS

Our analysis shows mixed associations between either BMI or the presence of parasitism and reported adult productivity. Muscularity was not clearly related to adult productivity. In contrast, body fatness (Skinfold z-score) was inversely associated with the average quantity of fish and game brought into the household, especially for men.

CONCLUSIONS

These findings suggest that the effects of adult infection and nutritional stress may be less clearly identified outside of the context of wage labor. Further research linking adult physical activity levels and metabolic rates to productivity in diverse contexts is needed.

Growth status among low-income Mexican and Mexican-American elementary school children

OBJECTIVES

Childhood obesity remains a problem among Latino children in the United States. Acculturation to an American diet and sedentary lifestyle may be causative factors. The research purpose was to assess child growth status, including sitting height, in relation to acculturation among Mexican and Mexican-American children.

METHODS

Anthropometric measures of weight, height, and sitting height were taken in a cross-sectional survey of Mexican and Mexican-American elementary school children (N = 484) in Phoenix, Arizona. Height-for-age (HAZ), weight-for-age (WAZ), and body mass index (BMI) Z-scores were calculated based on the Centers for Disease Control 2000 growth reference. Sitting height Z-scores (SHZ) were determined from the NHANES III reference values. Questions about language usage were asked of the children as a proxy for acculturation. Differences in growth measures and acculturation between those born in the United States or Mexico were evaluated by chi-square or t-tests.

RESULTS

The mean HAZ value (-0.23) was close to the reference median. There were no significant differences in HAZ or SHZ by birth country or gender. WAZ values for boys were significantly higher than for girls. More girls (64%) than boys (54%) had normal BMIs. More Mexican-born boys (28%) were obese than Mexican-born girls (17%; P = 0.026) in comparison to the US-born boys (31%) and girls (24%; P = n.s.). Acculturation scale score and male gender predicted a small percentage of the variation in BMIZ.

CONCLUSIONS

Environmental and cultural factors that promote obesity among low-income Mexican and Mexican-American children are similar regardless of birth country but boys may be at greater risk of obesity than girls.