Estimation of true height: a study in population-specific methods among young South African adults

Race and geography impact validity of maximum allowable standing height equations for para-athletes

World Athletics use maximum allowable standing height (MASH) equations for para-athletes with bilateral lower extremity amputations to estimate stature and limit prosthesis length since longer prostheses can provide running performance advantages. The equations were developed using a white Spanish population; however, validation for other races and geographical groups is limited. This study aimed to determine the validity of the MASH equations for Black and white Americans and whether bias errors between calculated and measured stature were similar between these populations. Sitting height, thigh length, upper arm length, forearm length, and arm span of 1899 male and 1127 female Black and white Americans from the Anthropometric Survey of US Army Personnel database were input into the 6 sex-specific MASH equations to enable comparisons of calculated and measured statures within and between Black and white groups. Two of 12 MASH equations validly calculated stature for Black Americans and 3 of 12 equations were valid for white Americans. Bias errors indicated greater underestimation or lesser overestimation of calculated statures in 10 equations for Black compared to white Americans and in 2 equations for white compared to Black Americans. This study illustrates that race and geography impact the validity of MASH equations.

Correlation analysis between body mass index and foot length in Chinese adolescents: a regional study

This study aims to analyse the relationship between body mass index and foot length in Chinese adolescents and to provide theoretical guidance for preventing a flat foot in Chinese adolescents. This study recruited 1477 students aged 14-23 years. The participants' height, weight, and body mass index were measured, as well as baseline data, including age, gender and foot length. Differences in foot length (bilateral) and flat foot distribution were statistically significant except for the normal foot and high arch foot distribution based on different body mass index groups. Linear correlation analysis demonstrated that body height, weight and body mass index were positively correlated with bilateral foot length regardless of gender. Body mass index acted as a risk factor for flat foot (bilateral) through disordered multi-classification logistic regression analysis. Body mass index was positively correlated with left and right foot length regardless of gender and acted as a risk factor for a flat foot in Chinese adolescents. Practitioner summary: Significant differences exist in the anthropometric data of various races and ethnic groups. The study was investigated in the form of a cross-sectional study. BMI was positively correlated with bilateral foot length and acted as a risk factor for a flat foot in Chinese adolescents.

Maternal overweight and obesity and its associated factors and outcomes in human immunodeficiency virus (HIV)-infected and HIV-uninfected black South African pregnant women

AIM

This study aimed to investigate various variables between maternal overweight and/or obesity versus normal-weight pregnant black South African women living with and without human immunodeficiency virus (HIV).

METHODS

A cross-sectional study design was employed. A total of 200 pregnant women were enrolled in the study, categorized according to body mass index (BMI) (kg/m² ) into two groups: (1) overweight/obese (≥25 kg/m² ) (n = 97); and (2) nonoverweight/nonobese (<25 kg/m² ) (n = 103), where 90 were HIV-infected and 110 were HIV-uninfected. The differences between the maternal BMI categories were assessed using Fisher's exact t-test and the χ² test. Simple and multiple logistic regression analyses were used to determine factors associated with maternal overweight and obesity.

RESULTS

Multiple logistic regression analysis showed that maternal age (odds ratio [OR]: 1.061; 95% confidence interval [CI] 1.008-1.117; p = 0.023) and gestational age (OR: 1.121; 95% CI 1.005-1.251; p = 0.041) were significantly associated with maternal overweight/obesity in both HIV-infected and HIV-uninfected. For maternal health outcomes, multiple logistic regression analysis showed that hypertensive disorders (OR: 0.273; 95% CI 0.124-0.601; p = 0.001) and anemia (OR: 2.420; 95% CI 1.283-4.563; p = 0.006) were significantly associated with maternal overweight/obesity in both HIV-infected and HIV-uninfected. The overweight/obese HIV-infected participants (OR: 0.233; 95% CI 0.075-0.717; p = 0.011) had increased odds for developing hypertensive disorders compared to HIV-uninfected overweight/obese participants (OR: 0.471; 95% CI 0.172-1.291; p = 0.143).

CONCLUSIONS

Maternal overweight/obesity in both HIV-infected and HIV-uninfected pregnant black South African women was significantly associated with maternal age, gestational age, HPT disorders, and anemia. Maternal overweight/obesity decreased the odds for anemia, but increased the odds for the development of HPT disorders, especially in the HIV-infected pregnant women.

Using tibial fragments to reconstruct the total skeletal height of black South Africans

Stature is an important component of the biological profile of unknown skeletal remains and regression equations for estimating stature have been derived for a number of bones. However, bones are rarely recovered intact in both forensic and archaeological cases, and regression formulae for fragmentary remains have therefore been developed. These equations are, however, both sex- and population-specific, and while formulae exist for many populations, those using fragmentary tibiae do not exist for black South Africans. The aim of this study was therefore to establish regression equations for estimating total skeletal height (TSH), and thereby stature, from tibial fragments in a black South African population. A sample of 99 male and 99 female black South African skeletons were obtained from the Raymond A. Dart Collection of Human Skeletons and the TSH of each skeleton was calculated using the anatomical method. Eleven additional measurements representing tibial fragments were taken on each tibia, and both uni- and multivariate equations were established for estimating TSH from these fragments. All tibial variables were significantly, positively correlated with TSH, and equation correlations ranged between 0.41 and 0.91. The range of standard errors of estimate for the derived sex-specific (3.43-5.06 cm) and sex-pooled (3.44-5.94 cm) multivariate equations were slightly larger than those reported for intact tibiae in black (2.78-3.06 cm) and white (2.59-3.16 cm) South Africans. All uni- and multivariate-equations estimated TSH with moderate to high accuracy, which indicates that in the absence of intact tibiae, the equations presented in this study can be used to give accurate estimates of TSH, and thereby stature, for black South Africans.

The Use of Arm Span as a Substitute for Height in Calculating Body Mass Index (BMI) for Spine Deformity Patients

OBJECTIVE

To compare arm span and height in body mass index (BMI) calculation in patients with spinal curvature and investigate their impact on interpretation of BMI.

STUDY DESIGN

Prospective case-control cohorts.

SUMMARY OF BACKGROUND DATA

The BMI value is based on weight to height ratio. Spine deformity patients experience height loss and its use in calculating BMI is likely to produce errors. A surrogate for height should therefore be sought in BMI determination.

METHODS

Ninety-three spine deformity patients were matched with 64 normal children. Anthropometric values (height, arm span, and weight) and spinal curve were obtained. BMIs using arm span and height were calculated, and statistical analysis performed to assess the relationship between BMI/height and BMI/arm span in both groups as well as the relationship between these values and Arm Span to Height difference (Delta AH).

RESULTS

There were 46 males and 47 females, the average age was 15.5 years in Group 1 versus 33 males and 31 females, average age 14.8 years in Group 2. Major scoliosis in Group 1 averaged 125.7° (21° to 252°). The extreme curves show vertebral transposition, with overlapping segments making it more than 180°. A logistic regression showed that there was linearity in BMI scores (R² = 0.97) for both arm span and height (R² = 0.94) in group 2 patients. For group 1 patients there was a significant difference in the BMI values when comparing BMI/arm span versus BMI/height (p < .0001). Mean BMI values using height was overstated by 2.8 (18.6%). The threshold at which BMI score must be calculated using arm span as opposed to the height (Delta AH) was determined to be 3 cm.

CONCLUSIONS

Spine deformity patients experience height loss, which can impact their true BMI values thereby giving an erroneous impression of their nutritional status. The arm span should be used in patients with Delta AH >3 cm to properly assess nutritional status.