Body shape indices and cardiometabolic risk in adolescents

Background: “A Body Shape Index” (ABSI) is a recently proposed index that standardizes waist circumference for body mass index (BMI) and height using the scaling exponents 2/3 and 1/2, respectively, estimated from adults. Incidentally, waist-to-height ratio has been suggested as an indicator of cardiometabolic risk in adolescents.

Aims: This study aims to estimate the scaling exponents for standardizing waist circumference for BMI and height in Chinese adolescents and to estimate and compare the ability of various body shape indices in predicting cardiometabolic risk in adolescents.

Subjects and methods: Participants aged 10–17 years in the 2009 China Health and Nutrition Survey were analysed.

Results: The appropriate scaling exponents for standardizing waist circumference for BMI and height in this adolescent sample were 0.45 and 0.55, respectively. A new ABSI-adolescents was defined accordingly. Ignoring the age dependence in the scaling exponents would lead to confounded associations. The ABSI-adolescents and the waist-to-height ratio were more associated with glycated haemoglobin and pre-diabetes, but not blood pressure, than the BMI was.

Conclusion: The scaling exponent for standardizing waist circumference for BMI is age-dependent. Indices based on waist circumference adjusted for BMI are more associated with glycated haemoglobin than BMI in adolescents.     

Correlation of Proteinuria with Podocyte Foot Process Effacement in IgA Nephropathy: An Ultrastructural Study

Background: Proteinuria is an uncommon clinical manifestation of IgA nephropathy and is usually seen in cases with severe lesions like endocapillary proliferation. However, it is occasionally seen even with cases with mild glomerular manifestations and may even be of nephrotic range.

Predictor: Podocyte foot process effacement.

Outcome: Severity of proteinuria.

Measurements: Podocyte foot process effacement was measured. Morphometric analysis was performed on transmission electron microscope images using a computerized digital photomicrograph system (BioWizard 4.2 Image analysis software, New Delhi, India). Proteinuria was measured quantitatively assigned into five grades.

Results: It was found that as the extent of proteinuria increased, the effacement ratio also increased, and this was most significant between “no” proteinuria and the rest of the categories.

Conclusion: Nephrotic presentation in IgA nephropathy is a known phenomenon and in certain cases may show near normal glomerular morphology with severe foot process effacement on EM being the only significant finding to explain the proteinuria. Proteinuria in these cases shows a significant correlation with degree of foot process effacement. Renal biopsy is important in these cases because they are known to have a better prognosis and are usually steroid responsive.     

Sitting height as a better predictor of body mass than total height and (body mass)/(sitting height)3 as an index of build

Background: The Rohrer Index and the ratio of sitting height (SH) to height fall similarly with growth in early childhood, then level off and rise slightly towards adulthood. In adults the BMI correlates with SH/height. The mean cross-sectional areas of the legs of adults are correlated positively with upper body masses and negatively with leg lengths.

Aim: To find an index of body build that is less dependent on relative leg length and age in children and adults than are the BMI and the Rohrer Index.

Subjects and methods: Published data are analysed to establish the relative importance of SH and leg length as predictors of body mass and to investigate the age dependence of the ratio (body mass)/SH³.

Results: SH is a much better predictor of body mass than height, with leg length being barely relevant. Average values of (body mass)/SH³ vary very little over the age range of 1–25 years, despite small non-random fluctuations.

Conclusion: The ratio (body mass)/SH³ is proposed as a useful “sitting-height index of build” that is superior to the Rohrer Index and could prove better than the BMI as a predictor of adiposity. Further studies are needed, notably using individual data and fat-free masses.     

Genetics of consanguinity and inbreeding in health and disease

Context: Inbreeding increases the level of homozygotes for autosomal recessive disorders and is the major objective in clinical studies. The prevalence of consanguinity and the degree of inbreeding vary from one population to another depending on ethnicity, religion, culture and geography. Global epidemiological studies have revealed that consanguineous unions have been significantly associated with increased susceptibility to various forms of inherited diseases.

Objective: The study aimed to determine the role of consanguinity in human health and to highlight the associated risks for various diseases or disorders.

Methods: PubMed and Google Scholar search engines were used to explore the published literature on consanguinity and its associated risks using the key words “consanguinity”, “prevalence”, “inbreeding depression”, “coefficient of inbreeding”, “child health”, “mortality”, “human health”, “homozygosity” and “complex diseases” in different combinations. The studies were screened for eligibility on the basis of their epidemiological relevance.

Results: This comprehensive assessment highlights the deleterious consequences in populations with a higher prevalence of consanguinity among different countries worldwide.

Conclusions: To avoid the inbreeding load there is the need to improve socioeconomic and educational status and to increase public awareness of reproductive health and anticipated deleterious effects. Pre-marital and pre-conception counselling of consanguineous populations should be an integral part of health policy to train people and make people aware of its harmful consequences. Furthermore, runs of homozygosity (ROH) and whole-exome sequencing (WES) are useful tools in exploring new genomic signatures for the cause of inbreeding depression.     

Isometric torso muscle endurance profiles in adolescents aged 15–18: normative values for age and gender differences

Objective: The aim of this study was to establish normative values for torso muscle endurance in adolescents aged 15–18 years. It was hypothesized that torso endurance profiles of adolescents differs between males and females and between adolescents and adults.

Background: Decreased torso muscle endurance has been identified as a potential personal risk factor for low back pain development in both adolescents and later years together with being detrimental for athletic performance.

Design: Measurement of torso muscle endurance, established through four tests performed in random order in a healthy adolescent population.

Setting: High school in Novi Sad, Province of Vojvodina, Republic of Serbia.

Methods: Two hundred and ninety-four adolescents from one high school (178 males and 116 females) were grouped into four age strata. Selected isometric torso muscle endurance tests were: Biering-Sørensen test for extensor endurance; Flexor endurance test; right and left Side Bridge tests. The mean, ratio, standard deviation and 25th, 50th and 75th percentile scores were determined for each gender/age strata.

Results and conclusion: Males had higher lateral torso endurance than females. Adolescents in general demonstrate their peak lifetime endurance as they appear more endurable than children and comparable adult groups. These data of endurance times, their ratios and percentiles in healthy normal subjects form a database bridging existing data for children and adults that may be useful for guiding training and rehabilitation.     

Down the rabbit hole: assessing the influence of schizotypy on the experience of the Barbie Doll Illusion

Introduction: “Body swapping” illusions have been used to explore factors contributing to the experience of “owning” an artificial body. Preliminary research indicated that those people diagnosed with schizophrenia experience more vivid illusions of this kind than do “normal” individuals.

Objectives: Here, we explored whether participants who rated themselves “high” on the cognitive-perceptual factor of the Schizotypal Personality Questionnaire (SPQ) experienced a more compelling sense of immersion in a variation of the body swapping illusion: The Barbie Doll Illusion. We also hypothesised that these individuals would experience a change in size perception when immersed in the illusion.

Method: Forty-four participants wore a pair of Head-Mounted Display goggles connected to a video-camera, and thus a doll’s body replaced their own body in their visual field. In two conditions, touch was either applied synchronously or asynchronously to the doll’s and each participant’s leg. After each condition, participants filled out a questionnaire relating to their experience in the illusion. When both conditions were completed, they filled out the SPQ.

Results: Our first hypothesis was confirmed, which suggested that people with higher cognitive-perceptual SPQ scores do indeed experience a more compelling Barbie Doll Illusion; however, our second hypothesis was not supported.

Conclusion: Our study demonstrated, for the first time, that proneness to the positive and interpersonal factors of schizotypy in a normal population is sufficient to produce a compelling sense of swapping bodies.     

Trends in thin body stature among Japanese male adolescents, 2003–2012

Background: The desire for thin body stature and unhealthy eating behaviours have spread among Japanese boys. The prevalence of thinness in boys is expected to increase; however, recent trends have not been reported.

Aim: To describe changes in the distribution of body mass index (BMI) of Japanese boys, from 2003 to 2012.

Subjects and methods: BMI distribution changes were studied in 2599 relatively affluent Japanese children and adolescents, aged 12.5–17.5 years, during 2003–2012. The 2003 and 2004 data were combined and compared to the combined 2011 and 2012 data. Tukey mean-difference plots were used to study the direction and magnitude of shifts in BMI distributions.

Results: Prevalence of thinness has progressively increased from 2.8–4.7% in 2003–2004 to 5.1–7.6% in 2011–2012 in Japanese boys. Tukey plots showed that the increases in the prevalence of thinness are related to shifts in the entire distribution of BMI in the sample.

Conclusion: Thin body stature was documented in increasing proportion of Japanese male adolescents. BMI z-scores decreased across the entire BMI centile spectrums, indicating that the whole school population may be at risk of thinness.     

Age as a moderator of the secular trend for grip strength in Canada and the United States

Purpose: To determine whether grip strength changed on average over recent decades at each of two age levels (children and adolescents versus adults) in Canada and the US.

Methods: For each sex, weighted least squares regression analyses were performed on mean grip strength values as reported in studies conducted from the 1960s onwards.

Results: Grip strength did not change significantly as a function of year tested in children and adolescents, whereas it declined as a negatively accelerated function of year tested in adults.

Conclusion: The results are contrary to what might be expected given that body weight has increased in both countries in recent decades and given that grip strength has been found to be positively correlated with body weight. It is suggested that there was a concurrent change in a factor that operated to counteract the effect of increased body weight on grip strength, a prime candidate being a decrease in levels of serum vitamin D. It is also suggested that the secular decline in adult grip strength can be explained by a factor that affects muscular function but which has a long latency period, a prime candidate here being obesity history.     

Trends in thin body stature among Japanese female adolescents, 2003–2012

Background: The past decades have witnessed a steady increase in thin body stature associated with unhealthy dieting among Japanese female adolescents. The most recent trends in thinness, however, have not been reported.

Aim: To describe changes in the distribution of body mass index (BMI) of Japanese female adolescents, from 2003–2012.

Subjects and methods: This study examined BMI distribution changes in 2541 relatively affluent Japanese girls, aged 12.5–17.5 years, during 2003–2012. The 2003 and 2004 data were combined and compared to the combined 2011 and 2012 data. Tukey mean-difference plots were used to study the direction and magnitude of shifts in BMI distributions.

Results: Prevalence of thinness (BMI <5th percentile of the 1978–1981 references) has progressively increased from 2.0–5.7% in 2003–2004 to 3.5–7.8% in 2011–2012 in Japanese girls. The downward shift in BMI was larger in 12.5–14.5 year olds than in 15.5–17.5 year olds and more prominent in the lower BMI spectrum.

Conclusion: The trend towards thinness has continued in Japanese girls during the past decade. The distribution of BMI suggests thinner and younger sub-groups of girls are more susceptible to this trend.     

Humans are not cooperative breeders but practice biocultural reproduction

Context: Alloparental care and feeding of young is often called “cooperative breeding” and humans are increasingly described as being a cooperative breeding species.

Objective: To critically evaluate whether the human offspring care system is best grouped with that of other cooperative breeders.

Methods: (1) Review of the human system of offspring care in the light of definitions of cooperative, communal and social breeding; (2) re-analysis of human lifetime reproductive effort.

Results: Human reproduction and offspring care are distinct from other species because alloparental behaviour is defined culturally rather than by genetic kinship alone. This system allows local flexibility in provisioning strategies and ensures that care and resources often flow between unrelated individuals. This review proposes the term “biocultural reproduction” to describe this unique human reproductive system. In a re-analysis of human life history data, it is estimated that the intense alloparenting typical of human societies lowers the lifetime reproductive effort of individual women by 14–29% compared to expectations based upon other mammals.

Conclusion: Humans are not cooperative breeders as classically defined; one effect of the unique strategy of human biocultural reproduction is a lowering of human lifetime reproductive effort, which could help explain lifespan extension.     

Body image,body dissatisfaction and weight status in children from Emilia-Romagna (Italy): comparison between immigrant and native-born

Background: Cross-sectional study among immigrant and native children from Emilia-Romagna (Italy).

Aim: The purpose of the present study was to examine the relative contribution of weight status, ethnicity and sex on body dissatisfaction in a sample of children from Emilia-Romagna (Italy).

Subjects and methods: Primary school children (226 immigrants and 1206 Italians) aged 6–11 years were measured: immigrant children were divided into Asians, Africans, Latin Americans and East Europeans. Height and weight were measured and Body Mass Index (BMI) was calculated. Body image perception was assessed using Body Silhouette Charts. A body dissatisfaction score (BDS) was derived by subtracting the "ideal self" from the "self" score.

Results: Weight status disorders were higher in immigrants than in native-born males; Italian females had higher prevalence of underweight and overweight and lower prevalence of obesity than immigrants peers. BDS rose with the increase of weight status categories.

Conclusions: Awareness of body image size and increasing body dissatisfaction with higher weight status is established in childhood, regardless of ethnicity and gender.     

Internal versus external auditory hallucinations in schizophrenia: symptom and course correlates

Introduction. The auditory hallucinations associated with schizophrenia are phenomenologically diverse. “External” hallucinations classically have been considered to reflect more severe psychopathology than “internal” hallucinations, but empirical support has been equivocal.

Methods. We examined associations of “internal” versus “external” hallucinations with (1) other characteristics of the hallucinations, (2) severity of other symptoms and (3) course of illness variables, in a sample of 97 stable outpatients with schizophrenia or schizoaffective disorder who experienced auditory hallucinations.

Results. Patients with internal hallucinations did not differ from those with external hallucinations on severity of other symptoms. However, they reported their hallucinations to be more emotionally negative, distressing and long-lasting, less controllable and less likely to remit over time. They also were more likely to experience voices commenting, conversing or commanding. However, they also were more likely to have insight into the self-generated nature of their voices. Patients with internal hallucinations were not older, but had a later age of illness onset.

Conclusions. Differences in characteristics of auditory hallucinations are associated with differences in other characteristics of the disorder, and hence may be relevant to identifying subgroups of patients that are more homogeneous with respect to their underlying disease processes.     

Reference values of vertical jumping performances in healthy Tunisian adolescent

Background: The assessment of normal values of muscle strength can be determined for the health outcome of adolescents, especially those who are living in a developing country.

Aims: The purpose of this study is to identify the relationship between anthropometric variables and vertical jumping performances. The jump height and the average of power were measured to establish reference values of vertical jumping parameters in Tunisian healthy adolescents aged 13–19 in both sexes.

Subjects and methods: Five hundred and twenty-five school adolescents (242 males and 283 females) were randomly selected to participate in this study. Maximum height and average of power reached in countermovement jump and squat jump were provided by an Optojump device. Full and stepwise regression models were used to identify which anthropometric parameters significantly contributed to performance variables.

Results: All anthropometric parameters increased with age. Reference values and multiple prediction equations of vertical jump parameters were set based on a large sample of healthy Tunisian adolescents. The multiple regressions showed that age, mass, sitting height, waist size, fat-free mass and leg muscle volume for boys and mass for girls were the best predictors of jumping performances.

Conclusion: This study provides normative data for jumping performances in Tunisian healthy adolescents aged 13–19 in both sexes. The percentiles values are calculated to estimate the levels of adolescents with high or low jumping performances.     

Obesity and body size perceptions in a Spanish Roma population

Background: Roma people are particularly vulnerable to developing overweight and obesity. Self-perception of body image may influence the prevalence of obesity in this ethnic minority.

Aim: The objectives of this study are to estimate the prevalence of obesity, to analyse body size perceptions and preferences and to assess the relationship between body size perceptions and obesity in the Roma population.

Subjects and methods: The analyses were carried out on 372 men, women and children from the Roma population residing in the Greater Bilbao region (Basque Country, Spain). In adults, a standard figural scale was used to analyse body size perceptions and preferences in this ethnic minority.

Results: Overall 51.7% of adult and 24.4% of minor Roma individuals were obese. Both Roma men and women had inaccurate self-perceptions of their body size. Significant differences on body size perceptions were detected based on age, sex, nutritional status and socioeconomic characteristics.

Conclusion: This Roma population presents one of the highest rates of obesity worldwide. Although a certain awareness of the correct weight status was appreciated, the inability of Roma individuals to see themselves as overweight or obese may be a significant factor on the high prevalence of obesity in this population.     

Secular trends in cranial morphological traits: a socioeconomic perspective of change and sexual dimorphism in North Americans 1849–1960

Background: The human body has undergone significant changes in stature and other areas, which reflect secular trends associated with socioeconomics.

Aim: To analyse cranial morphological traits for deciphering if they are subject to secular trends.

Subjects and methods: Two documented skeletal collections were sampled for a total of 525 individuals from 1849–1960. Cranial morphological traits were scored and input into time series statistics (logistic regression).

Results: In females, nuchal crests have enlarged, while glabella has decreased. In males, supraorbital margins have dulled, while glabella decreased. Sexual dimorphism increased in supraorbital margins.

Conclusion: The patterns in the data here reflect those found in other areas of the skeleton, namely height, as regards to secular trends. These findings can be extended to stature and cranial changes that parallel socioeconomic trends during the Industrial Revolution, antebellum period and after.     

Modelling foetal growth in a bi-ethnic sample: results from the Born in Bradford (BiB) birth cohort

Background: Attempts to explain the increased risk for metabolic disorders observed in South Asians have focused on the “South Asian” phenotype at birth and subsequent post-natal growth, with little research on pre-natal growth.

Aim: To identify whether divergent growth patterns exist for foetal weight, head (HC) and abdominal circumferences (AC) in a sample of Pakistani and White British foetuses.

Subjects and methods: Models were based on 5553 (weight), 5154 (HC) and 5099 (AC) foetuses from the Born in Bradford birth cohort. Fractional polynomials and mixed effects models were employed to determine growth patterns from ～15 weeks of gestation-birth.

Results: Pakistani foetuses were significantly smaller and lighter as early as 20 weeks. However, there was no ethnic difference in the growth patterns of weight and HC. For AC, Pakistani foetuses displayed a trend for reduced growth in the final trimester.

Conclusion: As the pattern of weight and HC growth was not significantly different during the period under investigation, the mechanism culminating in the reduced Pakistani size at birth may act earlier in gestation. Reduced AC growth in Pakistanis may represent reduced growth of the visceral organs, with consequences for post-natal liver metabolism and renal function.     

Neurocognitive insight and executive functioning in schizophrenia

Introduction. This study explored whether integrity of executive functioning is required for good neurocognitive insight (NI) in subjects with schizophrenia.

Methods. NI was measured by subtracting executive difficulties (errors in the Modified Card Sorting Task) from executive cognitive complaints (Subjective Scale to Investigate Cognition in Schizophrenia) in 40 outpatients with schizophrenia and 42 normal controls. The schizophrenia sample was a priori divided into two subgroups on the basis of executive level. Multivariate analyses were conducted to compare groups and to control for potential confounding factors.

Results. Only the schizophrenia dysexecutive subgroup had a poorer NI compared to normal controls. Group differences remained significant after adjustment for potential confounding factors (education, depression, anxiety and self-esteem).

Conclusion. These results provide support for the hypothesis that executive dysfunctioning is a limiting factor for NI, independently from depressive and anxiety symptoms.     

Indigenous populations in transition: An evaluation of metabolic syndrome and its associated factors among the Toba of northern Argentina

Background: The health problems associated with rapidly changing lifestyles in indigenous populations, e.g. cardiovascular disease, are becoming a public health concern.

Aim: The objective of this study was to evaluate the prevalence of metabolic syndrome and analyse the metabolic conditions that define this syndrome, in an indigenous Toba community of northern Argentina.

Subjects and methods: A total of 275 adults participated in this study. Anthropometric (BMI, body fat percentage, waist circumference) and clinical measures (blood pressure, cholesterol, glucose and triglycerides) were taken. Pearson and logistic regressions were used in the statistical analysis of risk factors for metabolic syndrome by sex and by reproductive status in women.

Results: The overall prevalence of metabolic syndrome was 38%. Nearly a third (31%) of the population was overweight and 45% obese. Men had significantly higher blood pressure and levels of triglycerides than women, while women had higher percentages of body fat. BMI was significantly associated with most of the risk factors for metabolic syndrome. Menopausal women had a higher prevalence of metabolic syndrome than women of reproductive age.

Conclusion: Metabolic syndrome was highly prevalent in this indigenous community, which places them at an increased risk for cardiovascular disease.     

Reference charts of sitting height,leg length and body proportions for Chinese children aged 0–18 years

Background: The reference charts of sitting height (SH), subischial leg length (LL) and the sitting height/leg length ratio (SH/LL) are useful tools in assessing body proportion for clinicians and researchers in related areas. However, reference charts of body proportions for Chinese children and adolescents are limited.

Aim: To construct reference charts of SH, LL and SH/LL for Chinese children and adolescents.

Subjects and methods: Stature and sitting height of 92 494 (46 240 boys and 46 254 girls) healthy Han nationality children, aged 0–18 years, were measured in two national large-scale cross-sectional surveys in 2005 in China. SH/LL was selected as the indicator of body proportion. References of SH, LL and SH/LL were constructed using the LMS method.

Results: The reference charts demonstrated that SH and LL increased with age. Growth in SH slowed by the age of 17 years in boys and 15 years in girls. Similarly, growth in LL slowed at 16 years in boys and 14 years in girls. The SH/LL ratio declined from birth (2.00 in boys and 2.03 in girls) to 13 years in boys (1.11) and to 11 years in girls (1.13), then increased slightly to the age of 18 (1.16 in boys and 1.18 in girls). The gender difference of SH/LL was not significantly different before the age of 11 years. After the age of 11, SH/LL appeared elevated in girls compared to boys.

Conclusions: The reference charts of SH, LL and SH/LL are useful tools for assessing body proportions for Chinese children and adolescent individuals.     

Long-term changes in body composition and prevalence of overweight and obesity in girls (aged 3–18 years) from Kraków (Poland) from 1983, 2000 and 2010

Background: Body mass disorders are an increasing problem, especially in industrialized countries.

Aim: Determination of time- and age-related differences in the prevalence of overweight, obesity and in body composition in girls from 1983, 2000 and 2010.

Subject and methods: In 2010 an anthropological study was conducted on 1970 girls aged 3–18 years living in Kraków (Poland). Data on selected skin-folds, BMI, muscle mass and bone mass were compared to two studies on analogous populations carried out in 1983 and 2000.

Results: Compared to 1983, the share of overweight girls in 2010 had decreased (from 12.4% to 11.2%), while the obesity rate had increased slightly from 2.3% to 3.2%. Girls from 2010 had lower overall body fat content than their peers studied in 1983. However, in 2010 suprailiac adiposity prevalence was higher, while triceps, subscapular and abdominal adiposity rates were lower. They also had higher muscle mass and lower bone mass.

Conclusion: The prevalence of overweight and obesity has not changed significantly over the last 30 years. However, significant changes have occurred in body composition. Girls measured in 2010 had lower total adipose tissue, although they also showed a tendency towards increased central adiposity.