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. Am J Phys Anthropol 152:294–299, 2013. © 2013 Wiley Periodicals, Inc.     

Body mass index and depressive symptoms: instrumental‐variables regression with genetic risk score

The causal role of obesity in the development of depression remains uncertain. We applied instrumental‐variables regression (Mendelian randomization) to examine the association of adolescent and adult body mass index (BMI) with adult depressive symptoms. Participants were from the Young Finns prospective cohort study (n = 1731 persons, 2844 person‐observations), with repeated measurements of BMI and depressive symptoms (modified Beck's Depression Inventory). Genetic risk score of 31 single nucleotide polymorphisms previously identified as robust genetic markers of body weight was used as a proxy for variation in BMI. In standard linear regression analysis, higher adult depressive symptoms were predicted by higher adolescent BMI (B = 0.33, CI = 0.06–0.60, P = 0.017) and adult BMI (B = 0.47, CI = 0.32–0.63, P < 0.001). These associations were replicated in instrumental‐variables analysis with genetic risk score as instrument (B = 1.96, CI = 0.03–3.90, P = 0.047 for adolescent BMI; B = 1.08, CI = 0.11–2.04, P = 0.030 for adult BMI). The association for adolescent BMI was significantly stronger in the instrumented analysis compared to standard regression (P = 0.04). These findings provide additional evidence to support a causal role for high BMI in increasing symptoms of depression. However, the present analysis also demonstrates potential limitations of applying Mendelian randomization when using complex phenotypes.     

Weight-height relationships and body mass index: some observations from the Diverse Populations Collaboration

Body mass index (BMI, weight (kg)/height (m)(2)) is the most widely used weight-height index worldwide. This universal use of BMI assumes that the rationale for its use is universally applicable. We examine two possible rationales for using BMI as a universal measure. The first rationale is that BMI is strongly correlated with weight, but is independent of height. The second rationale is that BMI correctly captures the relationship between weight and height, which implies that the slope of log weight regressed on log height is 2. We examined the weight-height relationship in 25 diverse population samples of men and women from the US, Europe, and Asia. The analysis included 72 subgroups with a total of 385,232 adults aged 25 years and older. Although BMI was highly correlated with weight in all studies, a significant, negative correlation between BMI and height was found in 31 out of 40 subgroups of men (r=-0.004 to -0.133) and 32 of 32 groups of women (r=-0.016 to -0.205). When log weight was regressed on log height, the 95% confidence intervals (CI) of the slopes did not include 2 in 25 out of 40 male subgroups. The summary estimate of the slopes across studies of men was 1.92 (95% CI, 1.87-1.97). For women, slopes were lower than 2 in 28 of 32 subgroups with a summary estimate of 1.45 (95% CI, 1.39-1.51). In most of the populations, BMI is not independent of height; weight does not universally vary with the square of height; and the relationship between weight and height differs significantly between males and females. The use of a single BMI standard for both men and women cannot be justified on the basis of weight-height relationships.     

The effect of oral glucose tolerance testing on changes in arterial stiffness and blood pressure in elderly women with hypertension and relationships between the stage of diabetes and physical fitness levels

[Purpose] The purpose of this study was to assess changes in blood glucose level, blood pressure, and arterial stiffness after a 75 g oral glucose tolerance test (OGTT) in elderly women aged over 65 years with hypertension and either normal glycemic control, impaired fasting glucose tolerance, or diabetes mellitus. We also wished to investigate the relationship between stages of diabetes and physical fitness.[Methods] A total of 24 elderly women with hypertension were assigned to a control group (CON; n=7), impaired fasting glucose group (IFG; n=9), and diabetes mellitus group (DM; n=8). In each group, blood glucose level, brachial ankle pulse wave velocity (PWV), and blood pressure were measured at baseline as well as 60 and 120 minutes after a 75 g OGTT. Physical fitness factors such as hand grip strength, balance test, 4 m gait speed test, chair stand test, short physical performance battery, and 6-minute walking test were subsequently assessed.[Results] In all three groups, blood glucose levels were significantly increased at 60 and 120 minutes after a 75 g OGTT. In the DM group, blood glucose levels were significantly higher before and after a 75 g OGTT than in the CON group. In the CON group, PWV was significantly increased at 60 minutes after a 75 g OGTT; however, there were no changes in other groups after glucose ingestion. In the CON group, systolic and diastolic blood pressures were significantly decreased at 60 and 120 minutes after a 75 g OGTT compared to baseline. However, there was no change in blood pressure after ingestion in the DM group. The IFG group had greater grip strength than the CON group; however, there were no differences in other variables between the groups.[Conclusion] After a 75 g OGTT, elderly women with hypertension and diabetes maintain higher blood glucose levels compared to those with hypertension alone. Unlike elderly women with hypertension alone, those with hypertension and diabetes did not show changes in arterial stiffness and blood pressure after a 75 g OGTT. Therefore, elderly women with hypertension and diabetes may not be able to control their blood vessels following a 75 g OGTT due to impaired vascular endothelial function. Moreover, there was no association between diabetes stage and physical fitness in elderly women with hypertension.     

Body mass variation is negatively associated with brain size: Evidence for the fat-brain trade-off in anurans

Species can evolve diverse strategies to survive periods of uncertainty. Animals may either invest in energy storage, allowing them to decrease foraging costs, such as locomotion or risk of predation, or they may invest in better cognitive abilities helping them to flexibly adapt their behavior to meet novel challenges. Here, we test this idea of a fat-brain trade-off in 38 species of Chinese anurans by relating the coefficient of variation of body mass (CV_bodymass; as an indicator of how much animals invest into storage over the season) to brain anatomical features. After correcting for shared ancestry and body mass, we found a negative relationship between relative brain size and CV_bodymass. This indicates that anurans seem to trade-off physiological and cognitive buffering during energy shortages. As similar patterns have been reported in arboreal mammals and primates our findings suggest that the fat-brain trade-off, where animals either invest into physiological or cognitive strategies to survive harsh conditions, may be a general pattern across vertebrates.     

A GWAS assessment of the contribution of genomic imprinting to the variation of body mass index in mice

Background

Genomic imprinting is an epigenetic mechanism that can lead to differential gene expression depending on the parent-of-origin of a received allele. While most studies on imprinting address its underlying molecular mechanisms or attempt at discovering genomic regions that might be subject to imprinting, few have focused on the amount of phenotypic variation contributed by such epigenetic process. In this report, we give a brief review of a one-locus imprinting model in a quantitative genetics framework, and provide a decomposition of the genetic variance according to this model. Analytical deductions from the proposed imprinting model indicated a non-negligible contribution of imprinting to genetic variation of complex traits. Also, we performed a whole-genome scan analysis on mouse body mass index (BMI) aiming at revealing potential consequences when existing imprinting effects are ignored in genetic analysis.

Results

10,021 SNP markers were used to perform a whole-genome single marker regression on mouse BMI using an additive and an imprinting model. Markers significant for imprinting indicated that BMI is subject to imprinting. Marked variance changed from 1.218 ×10⁻⁴ to 1.842 ×10⁻⁴ when imprinting was considered in the analysis, implying that one third of marked variance would be lost if existing imprinting effects were not accounted for. When both marker and pedigree information were used, estimated heritability increased from 0.176 to 0.195 when imprinting was considered.

Conclusions

When a complex trait is subject to imprinting, using an additive model that ignores this phenomenon may result in an underestimate of additive variability, potentially leading to wrong inferences about the underlying genetic architecture of that trait. This could be a possible factor explaining part of the missing heritability commonly observed in genome-wide association studies (GWAS).     

Relationship between Body Mass Index and the Use of Healthcare Services in Australia

Objective: To examine the relationship between body mass index (BMI) and the use of medical and preventive health services. Research Methods and Procedures: This study involved secondary analysis of weighted data from the Australian 1995 National Health Survey. The study was a population survey designed to obtain national benchmark information about a range of health‐related issues. Data were available from 17,033 men and 17,174 women, ≥20 years or age. BMI, based on self‐reported weight and height, was analyzed in relation to the use of medical services and preventive health services. Results: A positive relationship was found between BMI and medical service use, such as medication use, visits to hospital accident and emergency departments (for women only); doctor visits, visits to a hospital outpatient clinics; and visits to other health professionals (for women only). A negative relationship was found in women between BMI and preventive health services. Underweight women were found to be significantly less likely to have Papanicolaou smear tests, breast examinations, and mammograms. Discussion: This research shows that people who fall outside the healthy weight range are more likely to use a range of medical services. Given that the BMI of industrialized populations appears to be increasing, this has important ramifications for health service planning and reinforces the need for obesity prevention strategies at a population level.     

Single nucleotide polymorphisms in the mitochondrial control region are associated with metabolic phenotypes and oxidative stress

Objective

To identify the mitochondrial DNA (mtDNA) single nucleotide polymorphisms (SNPs) in the control region and elucidate their role in metabolic phenotypes and oxidative stress.

Methods

A total of 861 nondiabetic subjects were enrolled, including 250 impaired fasting glucose (IFG) and 370 obese subjects (body mass index [BMI] > 25 kg/m²). Antioxidant status presented as total free thiol level was determined from serum samples. DNA was extracted from peripheral blood leucocytes, and the sequences were analyzed using the DNASTAR software. SNPs were identified by comparison with the Cambridge Reference Sequence.

Results

After adjusting odds ratios for age, sex, and BMI, the selected independently significant SNPs indicated 4 susceptible SNPs: SNP-16126C and SNP-16261T, which were related to abdominal obesity (P = 0.009; 0.06); SNP-16390A, related to hypertension (HTN) (P = 0.007); and SNP-16092C, related to decreased antioxidant capacity (P = 0.015). In the obese subgroup, 3 susceptible SNPs included SNP-16189C and SNP-16260T, which showed significantly higher IFG prevalence (P = 0.016 and 0.024, respectively), and SNP-16519C, which was significantly higher in the HTN group (P = 0.036). As to protective SNPs, 5 protective SNPs were identified in all subjects but only one SNP-16093C is consistent in obese group, which showed a significantly lower prevalence in patients with abdominal obesity and was associated with a higher antioxidant status (P < 0.001).

Conclusion

SNPs in the mtDNA control region are associated with metabolic phenotypes and oxidative stress markers. Some SNPs are relating to the interaction between obesity and genetic factors. The beneficial effects of these protective SNPs were insignificant and some susceptible SNPs became dominant within the obese subgroup. Subjects harboring these SNPs should avoid excessive weight gain.     

Socially selected ornaments and fitness: Signals of fighting ability in paper wasps are positively associated with survival,reproductive success,and rank

Many animals have ornaments that mediate choice and competition in social and sexual contexts. Individuals with elaborate sexual ornaments typically have higher fitness than those with less elaborate ornaments, but less is known about whether socially selected ornaments are associated with fitness. Here, we test the relationship between fitness and facial patterns that are a socially selected signal of fighting ability in Polistes dominula wasps. We found wasps that signal higher fighting ability have larger nests, are more likely to survive harsh winters, and obtain higher dominance rank than wasps that signal lower fighting ability. In comparison, body weight was not associated with fitness. Larger wasps were dominant over smaller wasps, but showed no difference in nest size or survival. Overall, the positive relationship between wasp facial patterns and fitness indicates that receivers can obtain diverse information about a signaler's phenotypic quality by paying attention to socially selected ornaments. Therefore, there are surprisingly strong parallels between the information conveyed by socially and sexually selected signals. Similar fitness relationships in social and sexually selected signals may be one reason it can be difficult to distinguish the role of social versus sexual selection in ornament evolution.     

2011和2019年生物多样性维护型国家重点生态功能区状态及变化评估

适时掌握国家生物多样性维护型重点生态功能区的生境质量状况及其变化特征,是国家生物多样性保护战略规划及措施实施的重要科学依据。针对生物多样性维护型国家重点生态功能区,重点考虑生态系统结构与功能、人类活动的生态胁迫、人类社会响应3方面影响因素,构建生物多样性综合评估指标体系,评估了生物多样性维护型国家重点生态功能区2011和2019年的状况及变化。结果表明：（1）从2011到2019年,生物多样性维护国家重点生态功能区内人口以迁出为主,但路网密度显著上升,人类干扰指数和生态空间破碎度仍然呈增加趋势;（2）2011和2019年,各生物多样性维护型生态功能区综合评估指数BDI总体上均维持在0.4以上,生境质量总体上处于中、良等级范围内;（3）从2011年到2019年,各生态功能区BDI值平均从0.582上升到了0.606,中、良等级的功能区占比从61.5%提升到了76.9%;（4）从2011年到2019年,有2个生态功能区的BDI值出现下降,占比15.4%。近十多年内,生物多样性维护型国家重点生态功能区总体上呈现持续向好的变化趋势,但人口密度、路网建设、生态空间破碎度等因素,仍然是今后一定时期内国家生物多样性保护面临的关键压力,而加大保护区面积并严格控制,是缓解压力的有效途径。     

老年男性原发性高血压患者脉压与颈动脉狭窄的相关分析

目的：探讨老年男性原发性高血压（EH）患者脉压（PP）与动脉粥样硬化性颈动脉狭窄（CS）的关系。方法：对入选的157例伴有颈动脉粥样硬化的老年男性EH患者行颈动脉超声检查,并收集行颈动脉超声检查前1年内的多次血压水平及临床资料,根据颈动脉狭窄程度分为：CS〈50％组（n=66）及CS≥50％组（n=91）,并进一步将颈动脉狭窄程度分级（I—V级）,分析颈动脉狭窄的危险因素及与脉压的相关性。结果：①CS≥50％组收缩压（SBP）及PP显著高于CS〈50％组,而舒张压（DBP）显著低于CS〈50％组（P〈0．05）,CS≥50％组的独立危险因素是外周动脉疾病（OR：4．543,95％CI：1．415．14．590）及脉压（OR：1．096,95％CI：1．038．1．157）;②CS分级与PP（r=0．402,P〈0．01）及血浆纤维蛋白原（FIB）（r=0．200,P〈0．05）呈正相关,经校正年龄、体重指数（BMI）、SBP、DBP、总胆固醇（TO）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-c）、低密度脂蛋白胆固醇（LDL-c）、D-二聚体（D-dimer）、血尿酸（UA）、空腹血糖（FBG）、氨基酸末端脑利钠肽前体（NT-proBNP）、总胆红素（TBIL）及直接胆红素（DBIL）等危险因素后,CS分级仍与PP及FIB有关。结论：老年男性原发性高血压患者脉压与颈动脉狭窄有关,治疗高血压的同时应当尽量减小脉压。     

Association between misalignment of circadian rhythm and obesity in Korean men: Sixth Korea National Health and Nutrition Examination Survey

ABSTRACT

Background: The disruption of circadian rhythm has been found to associate with obesity in vivo and in vitro. Sleep duration, eating habits, total feeding time, and nightshift work can also affect circadian rhythms. This study investigated the association between misalignment of circadian rhythm and obesity in Korean men, using a cross-sectional database.

Methods: This study used data from the Korean National Health and Nutrition Examination Survey (KNHANES), whose study population was 3,658 men aged 18 to 60 years. General and abdominal obesity was defined as a body mass index (BMI) ≥ 25 kg/m² and waist circumference ≥ 90 cm, respectively. Circadian rhythm factors were determined with a self-report questionnaire and included breakfast frequency, sleep duration, and work time. Frequency of breakfast was divided into regular breakfast (five to seven times a week) and irregular breakfast (less than five times a week). Sleep duration was divided into less than 7 hours, 7–9 hours, and over 9 hours. Working time was defined as day/evening, night shift, and other type. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for general and abdominal obesity were calculated using multivariable logistic regression according to the number of factors that disturb the circadian rhythm.

Results: Participants with 1 (aOR 1.34, 95% Cl 1.10–1.61) and ≥2 (aOR 1.62, 95% Cl 1.29–2.05) factors disturbing circadian rhythms were associated with elevated risk for general obesity. Similarly, those with 1 (aOR 1.33, 95% Cl 1.09–1.63) and ≥2 (aOR 1.70, 95% Cl 1.32–2.20) factors had elevated risk for abdominal obesity.

Conclusions: Factors disturbing the circadian rhythm were associated with general and abdominal obesity. Additional studies are needed, and associations with metabolic diseases should be investigated.     

The relationship between body mass and relative investment in testes mass in cetaceans: Implications for inferring interspecific variations in the extent of sperm competition

Based on sperm competition theory, percentage testes mass (% of total body mass) has been used to infer variations in the extent of sperm competition within mating systems of cetaceans. However, in most amniote taxa, including mammals, there is an underlying negative relationship between body mass and relative investment in testes mass, which must first be taken into account. Here, I identify a very strong nonlinear, negative relationship between body mass in cetaceans and relative investment in testes mass based on data from 31 species. As a result, if percentage testes mass alone is used to infer the relative extent of sperm competition in cetaceans, its importance in mating systems of smaller species is likely to be overestimated, whereas its role in larger species is likely to be underestimated. Similarly, there will also be systematic biases if this relationship is assumed to be linear when it is not. Therefore, it is essential that the underlying, nonlinear body mass–testes mass relationship is correctly taken into account when using relative investment in testes mass to estimate the relative levels of sperm competition in cetaceans. This is particularly important if such inferences are used to inform conservation strategies for endangered cetacean species.     

Variation in body mass index among Polish adults: effects of sex, age, birth cohort, and social class

Remains of 15 hominids were recovered within a Mousterian archaeological context in the cave of Qafzeh, Israel. Dated to ca. 95 kyr BP, this skeletal material has been crucial for understanding biological, chronological, and cultural aspects of anatomically modern ancient Homo sapiens. The high proportion of children (N = 8) in Qafzeh Cave is unique among Middle Palaeolithic sites and encourages the search for skeletal evidence of disease and trauma. We report on the case of one child, Qafzeh 12, ca. 3 years old (according to modern human reference standards), who manifests some outstanding skeletal abnormalities that indicate hydrocephalus.     

Body Anthropometry and the Risk of Hip and Wrist Fractures in Men: Results from a Prospective Study

Available epidemiological information on the associations between body anthropometry and the incidence of fractures in men is limited. We therefore prospectively investigated the association between body anthropometry and the incidence of hip and wrist fractures from low and moderate trauma among 43,053 men who were 40 years to 75 years of age in 1986 when they first enrolled in the Health Professionals Follow-Up Study. After 8 years of follow-up, 201 wrist fracture cases and 56 hip fracture cases were reported. Greater height was associated with significant elevations in both hip and wrist fractures, whereas nonsignificant inverse associations were observed with weight and body mass index. Men in the highest quintile of waist circumference had a relative risk (RR) of 2.57 (95% confidence interval [CI] 0.64 to 10.3) for hip fracture and 2.05 (95% CI 1.06 to 3.96) for wrist fracture when compared with men in the lowest quintile. Waist-to-hip ratio was also positively related to fracture incidence; comparing highest with lowest quintile, the RRs were 3.92 (95% CI 1.07 to 14.3) for hip fracture and 1.50 (95% CI 0.85 to 2.66) for wrist fracture. These anthropometric indicators, in particular waist-to-hip ratio, may be useful for the prediction of hip fracture in adult men.     

Uncertainty associated with river health assessment in a varying environment: The case of a predictive fish-based index in France

Sensitive biological measures of river ecosystem quality are needed to assess, maintain or restore ecological conditions of water bodies. Since our understanding of these complex systems is imperfect, decision-making requires recognizing uncertainty. In this study, a new predictive multi-metric index based on fish functional traits was developed to assess French rivers. Information on fish assemblage structure, local environment and human-induced disturbances of 1654 French river sites was compiled. A Bayesian framework was used to predict theoretical metric values in absence of human pressure and to estimate the uncertainty associated with these predictions. The uncertainty associated with the index score gives the confidence associated with the evaluation of site ecological conditions.Among the 228 potential metrics tested, only 11 were retained for the index computation. The final index is independent from natural variability and sensitive to human-induced disturbances. In particular, it is affected by the accumulation of different degradations and specific degradations including hydrological perturbations. Predictive uncertainty is globally lower for IPR+ than for underlying metrics.This new methodology seems appropriate to develop bio-indication tools accounting for uncertainty related to reference condition definition and could be extended to other biological groups and areas. Our results support the use of multi-metric indexes to assess rivers and strengthen the idea that examination of uncertainty could contribute greatly to the improvement of the assessment power of bio-indicators.     

Age and growth of round goby Neogobius melanostomus associated with depth and habitat in the western basin of Lake Erie

Round goby Neogobius melanostomus were examined from the Bass Islands area in the western basin of Lake Erie, U.S.A., to determine age and growth correlations. A total of 188 specimens were collected and examined during summer 2011 with 90 aged using scale analysis. Fish were grouped by sex, depth of habitat and habitat type (anthropogenically modified shallows, natural shallows and open lake deep water). Fish ranged from 17 to 117 mm total length (L_T) and 0+ to 3+ years. Males dominated the population (1·94:1) and backcalculated age showed that both sexes grew exponentially, with male growth rate increasing faster than female. Males were significantly larger than females in L_T and mass (both P < 0·001). The relative mass index (W_r) was low for the sampled population (mean ± s.d . = 32·00 ± 26·87 g), implying that the health of the Bass Island area population is very poor when compared with the species throughout its range. This could be due to a lack of food resources related to population size or that the fish is not optimally utilizing the available food resources. In contradiction to these findings, regression slope coefficient (b), calculated using Fulton's condition factor (K) (mean ± s.d . =1·50 ± 0·20), was very low for each habitat, implying a healthy population throughout. This seemingly opposite effect may be due to more individuals per unit area in shallow waters, which would cause increased competition for resources. Poor condition may indicate that the Lake Erie population has reached saturation or may reflect indirect fitness costs associated with increasing anoxic or hypoxic hypolimnion conditions.