Effect of sex and age on bone mass, body composition and fuel metabolism in humans

Divergent multiomic acute exercise responses reveal the impact of sex as a biological variable

The majority of exercise physiology research has been conducted in males, resulting in a skewed biological representation of how exercise impacts the physiological system. Extrapolating male-centric physiological findings to females is not universally appropriate and may even be detrimental. Thus, addressing this imbalance and taking into consideration sex as a biological variable is mandatory for optimization of precision exercise interventions and/or regimens. Our present analysis focused on establishing multiomic profiles in young, exercise-naïve males (n = 23) and females (n = 17) at rest and following acute exercise. Sex differences were characterized at baseline and following exercise using skeletal muscle and extracellular vesicle transcriptomics, whole blood methylomics, and serum metabolomics. Sex-by-time analysis of the acute exercise response revealed notable overlap, and divergent molecular responses between males and females. An exploratory comparison of two combined exercise regimens [high-intensity tactical training (HITT) and traditional (TRAD)] was then performed using singular value decomposition, revealing latent data structures that suggest a complex dose-by-sex interaction response to exercise. These findings lay the groundwork for an understanding of key differences in responses to acute exercise exposure between sexes. This may be leveraged in designing optimal training strategies, understanding common and divergent molecular interplay guiding exercise responses, and elucidating the role of sex hormones and/or other sex-specific attributes in responses to acute and chronic exercise.NEW & NOTEWORTHY This study examined methylomics, transcriptomics, and metabolomics in circulation and/or skeletal muscle of young, healthy, exercise-naïve males and females before and after exposure to either traditional combined exercise (TRAD) and high-intensity tactical training (HITT). Across 40 young adults, we found an overlapping yet considerably sex-divergent response in the molecular mechanisms activated by exercise. These findings may provide insight into optimal training strategies for adaptation when considering sex as a biological variable.

Using music as a mood regulator in everyday life is associated with unfavourable health and fitness outcomes in overweight adults

Individual traits and habits have shown to be associated with health and health behaviour. One such habit is how individuals use music. This study aimed to examine if using music as a mood regulator is related to risk factors of lifestyle diseases. Participants who joined the present Motivation Makes the Move! lifestyle intervention were overweight and sedentary adults (n = 76, ages 19-40). They answered questionnaires about physical activity and use of music. They also underwent a cardiopulmonary exercise test and their body composition was assessed. Additionally, the analyses' robustness was tested through controlling for physical, sociodemographic and psychological health related factors. We observed that despite the participants' self-reported commitment to regular physical activity, their fitness level was poor. Using music as a mood regulator was associated with lower cardiorespiratory fitness. Use of music was also positively linked to body fat percentage, although this finding did not remain significant after adjusting for age, educational level and experienced health. We urge future research to address the relationship between music use and risk factors of lifestyle diseases in a population sample.

Obese adolescents have higher risk for femur fracture after motor vehicle collision

Background

Previous reports identified an association between obese adolescents (OAs) and lower extremity (LE) fractures after blunt trauma. However, the type of LE fracture remains unclear. We hypothesized that OAs presenting after motor vehicle collision (MVC) have a higher risk of severe LE fracture and will require a longer length of stay (LOS) and more support services upon discharge, compared to non-OAs.

Methods

The 2017-2019 Trauma Quality Improvement Program database was queried for adolescents (12-17-years-old) presenting after MVC. The primary outcome was LE fracture. A severe fracture was defined by abbreviated injury scale ≥3. OAs were defined by a body mass index (BMI) ≥30.

Results

From 22,610 MVCs, 3325 (14.7 %) included OAs. The rate of any LE fracture was higher for OAs (21.6 % vs. 18.8 %, p < 0.001). On subset analysis the only LE fracture at higher risk in OAs was a femur fracture (13 % vs. 9.1 %, p < 0.001). After adjusting for sex and age, the risk for severe LE fracture (OR 1.34, CI 1.18-1.53, p < 0.001) was higher for OAs. OAs with a femur fracture had a longer median LOS (5 vs. 4 days, p = 0.003) and were more likely discharged with additional support services including home-health or inpatient rehabilitation (30.6 % vs. 21.4 %, p < 0.001).

Conclusion

OAs sustaining MVCs have increased associated risk of femur fractures. OAs are more likely to have a higher-grade LE injury, experience a longer LOS, and require additional support services upon discharge. Future research is needed to determine if early disposition planning with social work assistance can help shorten LOS.

Effects of Exercise Type on Muscle Strength and Body Composition in Men and Women: A Systematic Review and Meta-Analysis

Background and Objectives: There are typical differences in body composition and distribution of muscle fiber types between women and men. However, research investigating the effects of exercise based on sex differences is limited, and studies examining sex differences in physiological adaptations according to exercise type are scarce. We aimed to compare the effects of exercise types on muscle strength and body composition in men and women through a meta-analysis. Materials and Methods: A systematic literature search was conducted using the PubMed/Medline, Web of Science, CINAHL, and EBSCO databases. Keywords included "endurance training", "resistance training", "concurrent training", "muscle strength", "body composition", "sex characteristics", and "men and women". The standardized mean difference (SMD) was presented separately for men and women based on the pre- and post-intervention values for each exercise type. Results: Concurrent training showed the greatest effect on the increase in leg press muscle strength in men, and resistance training showed the greatest effect in women. Concurrent training showed the greatest effect size in both men and women in increasing bench press muscle strength. Resistance training and concurrent training showed a small effect size on lean mass reduction in both men and women. Endurance training and concurrent training significantly reduced fat mass in men. However, no significant changes in fat mass were observed in any exercise type among women. Conclusions: Concurrent training is the most efficient type of exercise for men, as it is effective in increasing upper- and lower-body muscle strength, increasing lean mass, and reducing fat mass. Resistance training is most effective in increasing muscle strength in females, whereas endurance training is most effective in reducing fat mass. However, it is difficult to corroborate these results because of the lack of study samples included in the analysis and the differences in exercise methods, participant age, and exercise duration.

Roles of biochemistry data, lifestyle, and inflammation in identifying abnormal renal function in old Chinese

BACKGROUND

The incidence of chronic kidney disease (CKD) has dramatically increased in recent years, with significant impacts on patient mortality rates. Previous studies have identified multiple risk factors for CKD, but they mostly relied on the use of traditional statistical methods such as logistic regression and only focused on a few risk factors.

AIM

To determine factors that can be used to identify subjects with a low estimated glomerular filtration rate (L-eGFR < 60 mL/min per 1.73 m2) in a cohort of 1236 Chinese people aged over 65.

METHODS

Twenty risk factors were divided into three models. Model 1 consisted of demographic and biochemistry data. Model 2 added lifestyle data to Model 1, and Model 3 added inflammatory markers to Model 2. Five machine learning methods were used: Multivariate adaptive regression splines, eXtreme Gradient Boosting, stochastic gradient boosting, Light Gradient Boosting Machine, and Categorical Features + Gradient Boosting. Evaluation criteria included accuracy, sensitivity, specificity, area under the receiver operating characteristic curve (AUC), F-1 score, and balanced accuracy.

RESULTS

A trend of increasing AUC of each was observed from Model 1 to Model 3 and reached statistical significance. Model 3 selected uric acid as the most important risk factor, followed by age, hemoglobin (Hb), body mass index (BMI), sport hours, and systolic blood pressure (SBP).

CONCLUSION

Among all the risk factors including demographic, biochemistry, and lifestyle risk factors, along with inflammation markers, UA is the most important risk factor to identify L-eGFR, followed by age, Hb, BMI, sport hours, and SBP in a cohort of elderly Chinese people.

APOE ε4 and Alzheimer's disease diagnosis associated differences in L-carnitine, GBB, TMAO, and acylcarnitines in blood and brain

BACKGROUND

The apolipoprotein E (APOE) ε4 allele, involved in fatty acid (FA) metabolism, is a major genetic risk factor for Alzheimer's disease (AD). This study examined the influence of APOE genotypes on blood and brain markers of the L-carnitine system, necessary for fatty acid oxidation (FAO), and their collective influence on the clinical and pathological outcomes of AD.

METHODS

L-carnitine, its metabolites γ-butyrobetaine (GBB) and trimethylamine-n-oxide (TMAO), and its esters (acylcarnitines) were analyzed in blood from predominantly White community/clinic-based individuals (n = 372) and in plasma and brain from the Religious Order Study (ROS) (n = 79) using liquid chromatography tandem mass spectrometry (LC-MS/MS).

FINDINGS

Relative to total blood acylcarnitines, levels of short chain acylcarnitines (SCAs) were higher whereas long chain acylcarnitines (LCAs) were lower in AD, which was observed pre-clinically in APOE ε4s. Plasma medium chain acylcarnitines (MCAs) were higher amongst cognitively healthy APOE ε2 carriers relative to other genotypes. Compared to their respective controls, elevated TMAO and lower L-carnitine and GBB were associated with AD clinical diagnosis and these differences were detected preclinically among APOE ε4 carriers. Plasma and brain GBB, TMAO, and acylcarnitines were also associated with post-mortem brain amyloid, tau, and cerebrovascular pathologies.

INTERPRETATION

Alterations in blood L-carnitine, GBB, TMAO, and acylcarnitines occur early in clinical AD progression and are influenced by APOE genotype. These changes correlate with post-mortem brain AD and cerebrovascular pathologies. Additional studies are required to better understand the role of the FAO disturbances in AD.

The effect of the exercise environment and the level of involvement on bone mineral health

INTRODUCTION

This study aimed to compare athletes practicing exercise in different environments with non-active young and elderly men and women regarding bone mineral density (BMD), hypothesizing that BMD values differ between athletes according to the environment of exercise practice, but those training in a low-gravitational environment have no different stimuli to BMD increasing if compared with healthy peers experiencing reduced exercise involvement, whatever the age group and sex.

MATERIALS AND METHODS

104 participants of both sexes were selected according to the environment of exercise practice [swimmers (N = 26) and judo fighters (N = 26)], and exercise level of involvement [non-active young (N = 26) and older adults (N = 26)]. Dual-energy X-ray absorptiometry provided BMD, lean mass, and fat mass (FM) for the whole body (WB), upper (UL), and lower limbs (LL).

RESULTS

For the BMD in WB, UL and LL no effects of group and sex were observed (p > 0.05). Post-hoc analyses detected higher values of BMD in UL for female swimmers compared to non-active older adults (p < 0.05), while judo fighters showed higher BMD in WB, UL, and LL than other participants whatever the sex (p < 0.01). Lower FM was observed for WB, UL, and LL when swimmers and judo fighters were compared to non-active young and older female peers (p < 0.01).

CONCLUSION

The findings emphasized that BMD stimuli with swimming are reduced when compared to judo, and despite the stimuli in swimming is not distinguishable from that affecting BMD in WB, UL and LL of non-active young, it is effective in differing BMD in UL among non-active older for women.

Association of Body Fluid Volumes and Body Fat Distribution with Abnormal Ankle-Brachial Index

Background

Ankle-brachial index (ABI) is a simple, non-invasive and easy-to-obtain measure for the evaluation of atherosclerotic peripheral arterial disease (PAD). This study aimed to investigate the relationships between body fluid volumes, body composition, body fat distribution and ABI at a population perspective.

Results

Using the US National Health and Nutrition Examination Survey Data (NHANES) during 1999–2000, 2001–2002, and 2003–2004, adults ≥ 40 years old were eligible for inclusion. Univariate and multivariable linear and logistic regression analyses were performed to determine the associations between ABI, body fluid volume and body composition assessed by bioelectrical impedance analysis (BIA), and body fat distribution assessed by dual-energy X-ray absorptiometry (DEXA). After exclusion, the final analytic sample contained 1535 participants who were representative of totally 28,572,458 subjects in the US. After adjustments for relevant confounders, estimated fat mass was significantly and inversely associated with ABI (beta: − 0.0009, 95% CI = − 0.0015, − 0.0003). Total percent fat (beta: − 0.0024, 95% CI = − 0.0033, − 0.0014), trunk percent fat (beta: − 0.0016, 95% CI = − 0.0023, − 0.0009), and percent fat at the four limbs were also significantly and inversely associated with ABI (p < 0.001). In addition, subjects with higher estimated fat mass, total percent fat, trunk percent fat and higher percent fat at the four limbs were all significantly more likely to have abnormal ABI < 0.9. No significant association between parameters of body fluid volume and abnormal ABI was observed.

Conclusions

Estimated fat mass, total percent fat, trunk percent fat and percent fat at the four limbs were significantly and inversely associated with ABI. Subjects with abnormal ABI are more likely to have higher total percent fat, trunk percent fat and the limb fat. These findings fill the knowledge gap on the relationships between atherosclerosis and body fat distribution. Further well-designed prospective studies are needed to confirm the present findings.

Obesity, Weight Loss, Lifestyle Interventions, and Autosomal Dominant Polycystic Kidney Disease

Obesity remains a growing public health concern in industrialized countries around the world. The prevalence of obesity has also continued to rise in those with chronic kidney disease. Epidemiological data suggests those with overweight and obesity, measured by body mass index, have an increased risk for rapid kidney disease progression. Autosomal dominant polycystic kidney disease causes growth and proliferation of kidney cysts resulting in a reduction in kidney function in the majority of adults. An accumulation of adipose tissue may further exacerbate the metabolic defects that have been associated with ADPKD by affecting various cell signaling pathways. Lifestyle interventions inducing weight loss might help delay disease progression by reducing adipose tissue and systematic inflammation. Further research is needed to determine the mechanistic influence of adipose tissue on disease progression.

Anthropometric Characteristics in Taiwanese Adults: Age and Gender Differences

Population aging is creating critical issues in Taiwan, and adults are being forced to maintain productivity at work; in other words, they need to work longer. Therefore, their fitness and health warrant immediate attention. Although the association between health and anthropometric characteristics has been reported, few profiles on Taiwanese adults can be found. The purpose of this study was to provide a suitable reference on the anthropometric data of Taiwanese adults. We recruited 60,056 anthropometric measurements from a representative database. Significant differences were found in every measurement for each gender and age group. Statistically, our results indicated anthropometric differences in different ages. However, CVs showed that the dispersions are minor. This study presents a sufficient profile on Taiwanese adults from a representative database to practitioners and other potential users.

Global prevalence of sarcopenic obesity in older adults: A systematic review and meta-analysis

BACKGROUND & AIMS

Sarcopenic obesity (SO), which refers to the coexistence of sarcopenia and obesity. It can lead to physical disability, morbidity, and even mortality. This systematic review and meta-analysis aimed to estimate the global prevalence of SO in older adults.

METHODS

We searched PubMed, Embase, and Web of Science for studies reporting the prevalence of SO from inception to December 2020. Two researchers independently screened the literature, evaluated study quality, and extracted data. A random-effects model was used to pool the estimates for the prevalence of SO. Subgroup analysis, sensitivity analysis, and meta-regression analysis were conducted. Publication bias was assessed using a funnel plot and the Egger test. All statistical analyses were performed using Stata 15.0 software.

RESULTS

This review included 50 studies, we found that the global prevalence of SO in older adults was 11%. Subgroup analyses showed that the prevalence of SO was higher among studies using diagnostic criteria of muscle mass alone (15%) to diagnose sarcopenia, using dual-energy X-ray absorptiometry (15%) to assess muscle mass, and those focused on age ≥ 75 years old (23%), hospitalized (16%), South Americans (21%) and North Americans (19%). There were no significant differences in the prevalence of SO among studies using body fat percentage (10%), body mass index (13%), waist circumference (16%) to diagnose obesity and in female (14%), male (10%) patients. Sensitivity analysis showed that none of the studies affected the overall pooled results. Meta-regression analysis found that publication year, geographical region, study setting, and the diagnostic criteria of sarcopenia were sources of heterogeneity.

CONCLUSION

This meta-analysis indicated SO affects more than one in ten older adults globally. Therefore, we should attach importance to the screening and early diagnosis of SO in older adults, then selecting appropriate interventions to reduce the occurrence of it and various adverse outcomes in this demographic.

Oestrogen replacement fails to fully revert ovariectomy-induced changes in adipose tissue monoglycerides, diglycerides and cholesteryl esters of rats fed a lard-enriched diet

Menopause may be accompanied by abdominal obesity and inflammation, conditions accentuated by high-fat intake, especially of saturated fat (SFA)-rich diets. We investigated the consequences of high-SFA intake on the fatty acid (FA) profile of monoglycerides, diglycerides and cholesteryl esters from retroperitoneal white adipose tissue (RET) of rats with ovariectomy-induced menopause, and the effect of oestradiol replacement. Wistar rats were either ovariectomized (Ovx) or sham operated (Sham) and fed either standard chow (C) or lard-enriched diet (L) for 12 weeks. Half of the Ovx rats received 17β-oestradiol replacement (Ovx + E2). Body weight and food intake were measured weekly. RET neutral lipids were chromatographically separated and FAs analysed by gas chromatography. Ovariectomy alone increased body weight, feed efficiency, RET mass, leptin and insulin levels, leptin/adiponectin ratio, HOMA-IR and HOMA-β indexes. OvxC + E2 showed attenuation in nearly all blood markers. HOMA-β index was restored in OvxL + E2. OvxC showed significantly disturbed SFA and polyunsaturated FA (PUFA) profile in RET cholesteryl esters (CE). OvxC also showed increased monounsaturated FA (MUFA) in the monoglyceride diglyceride (Mono-Di) fraction. Similar changes were not observed in OvxL, although increased SFA and decreased PUFA was observed in Mono-Di. Overall, HRT was only partially able to revert changes induced by ovariectomy. There appears to be increased mobilization of essential FA in Ovx via CE, which is a dynamic lipid species. The same results were not found in Mono-Di, which are more inert. HRT may be helpful to preserve FA profile in visceral fat, but possibly not wholly sufficient in reverting the metabolic effects induced by menopause.

Cross-sectional associations of adipokines and abdominal fat distribution with aging in men

OBJECTIVE

To investigate the relationship of adipokines and abdominal fat distribution with aging in men.

METHODS

In a cross-sectional study, a total of 218 participants aged 40-79 years were recruited as a subset of the Prospective Urban Rural Epidemiology (PURE) China Action on Spine and Hip status (CASH) study population. Analysis of variance (ANOVA) and multivariable regression were used to estimate the associations of interest.

RESULTS

With the increasing of age, waist circumference, waist-to-hip ratio, waist-to-height ratio, total adipose tissue (TAT), visceral adipose tissue (VAT), VAT/subcutaneous adipose tissue (SAT), leptin, adiponectin-to-leptin ratio, and human monocyte chemo-attractant protein-1 (MCP-1) increased significantly (p < 0.05), while adiponectin decreased significantly (p < 0.05). Adiponectin, adiponectin/leptin, and adiponectin/resistin varied inversely with the VAT quartiles (p < 0.05). There was a significant negative correlation among adiponectin, adiponectin-to-leptin ratio, adiponectin-to-resistin ratio, and all the body fat distribution parameters. VAT was inversely and significantly associated with adiponectin, adiponectin-to-leptin ratio, and adiponectin-to-resistin ratio (p < 0.05).

CONCLUSIONS

It showed that aging, abdominal fat distribution, and adipokines were related with each other, which support the hypothesis that regulation of VAT and adipokines is closely linked to aging.

Ovariectomy modifies lipid metabolism of retroperitoneal white fat in rats: a proteomic approach

Menopause is often accompanied by visceral obesity. With the aim of exploring the consequences of ovarian failure on visceral fat, we evaluated the effects of ovariectomy and estrogen replacement on the proteome/phosphoproteome and on the fatty acid profile of the retroperitoneal adipose depot (RAT) of rats. Eighteen 3-mo-old female Wistar rats were either ovariectomized or sham operated and fed with standard chow for 3 mo. A subgroup of ovariectomized rats received estradiol replacement. RAT samples were analyzed with data-independent acquisitions LC-MS/MS, and pathway analysis was performed with the differentially expressed/phosphorylated proteins. RAT lipid profile was analyzed by gas chromatography. Ovariectomy induced high adiposity and insulin resistance and promoted alterations in protein expression and phosphorylation. Pathway analysis showed that five pathways were significantly affected by ovariectomy, namely, metabolism of lipids (including fatty acid metabolism and mitochondrial fatty acid β-oxidation), fatty acyl-CoA biosynthesis, innate immune system (including neutrophil degranulation), metabolism of vitamins and cofactors, and integration of energy metabolism (including ChREBP activates metabolic gene expression). Lipid profile analysis showed increased palmitic and palmitoleic acid content. The analysis of the data indicated that ovariectomy favored lipogenesis whereas it impaired fatty acid oxidation and induced a proinflammatory state in the visceral adipose tissue. These effects are consistent with the findings of high adiposity, hyperleptinemia, and impaired insulin sensitivity. The observed alterations were partially attenuated by estradiol replacement. The data point to a role of disrupted lipid metabolism in adipose tissue in the genesis of obesity after menopause.

Repository Describing an Aging Population to Inform Physiologically Based Pharmacokinetic Models Considering Anatomical, Physiological, and Biological Age-Dependent Changes

BACKGROUND

Aging is characterized by anatomical, physiological, and biological changes that can impact drug kinetics. The elderly are often excluded from clinical trials and knowledge about drug kinetics and drug-drug interaction magnitudes is sparse. Physiologically based pharmacokinetic modeling can overcome this clinical limitation but detailed descriptions of the population characteristics are essential to adequately inform models.

OBJECTIVE

The objective of this study was to develop and verify a population database for aging Caucasians considering anatomical, physiological, and biological system parameters required to inform a physiologically based pharmacokinetic model that included population variability.

METHODS

A structured literature search was performed to analyze age-dependent changes of system parameters. All collated data were carefully analyzed, and descriptive mathematical equations were derived.

RESULTS

A total of 362 studies were found of which 318 studies were included in the analysis as they reported rich data for anthropometric parameters and specific organs (e.g., liver). Continuous functions could be derived for most system parameters describing a Caucasian population from 20 to 99 years of age with variability. Areas with sparse data were identified such as tissue composition, but knowledge gaps were filled with plausible qualified assumptions. The developed population was implemented in Matlab^® and estimated system parameters from 1000 virtual individuals were in accordance with independent observed data showing the robustness of the developed population.

CONCLUSIONS

The developed repository for aging subjects provides a singular specific source for key system parameters needed for physiologically based pharmacokinetic modeling and can in turn be used to investigate drug kinetics and drug-drug interaction magnitudes in the elderly.

The association between obesity indices and obstructive sleep apnea is modified by age in a sex-specific manner

BACKGROUND

The beneficial effects of weight reduction on obstructive sleep apnea (OSA) are highly variable. Whether or not the variability is associated with the effects of age and sex remains unclear. This study examined this issue with large cross-sectional data.

METHOD

Anthropometric measurements, polysomnographic variables, biochemical indicators, and medical history were collected for each participant. Multivariable linear regression with interaction terms was used to estimate the modification effect of age on the associations between OSA severity (assessed by apnea-hypopnea index, AHI) with obesity indices (body mass index, BMI; neck circumference, NC; waist circumference, WC; waist-to-hip ratio, WHR) in a sex-specific manner, and vice versa. To facilitate interpretation of the results, participants were further classified into six subpopulations according to both sex and age, and population-specific beta-coefficients were calculated and compared.

RESULTS

A total of 5756 adults (4600 men) with suspected OSA were included in the study. BMI, NC, WC, and WHR were all positively correlated with AHI after adjusting for potential confounders in all populations. In men, these associations were much stronger and more significant in younger than older individuals (P for interaction < 0.001). For example, a 10% increase in BMI was independently associated with a 32% increase in AHI for men < 40 years old, whereas the corresponding increases were 21% and 17% for men 40-60 and > 60 years old, respectively. By contrast, no modification effect of age was observed in women (P for interaction > 0.05). A 10% increase in BMI was associated with 26%, 27%, and 24% increases in AHI for women < 40, 40-60, and > 60 years old, respectively.

CONCLUSIONS

Age modifies the associations between obesity indices and OSA severity in a sex-specific manner. These findings may broaden the understanding of age- and sex-related heterogeneities in the pathogenic role of obesity in OSA, and may be beneficial for individualized risk evaluation and treatment management for patients with OSA.

Estimation and projection about the standardized prevalence of osteoporosis in mainland China

We performed a systematic analysis of the standardized prevalence of osteoporosis in mainland China from 1990 to 2050.

INTRODUCTION

Osteoporosis is the most common bone disease. We aimed to investigate the standardized prevalence of osteoporosis in mainland China at the national and regional levels, with projections until 2050.

METHODS

A comprehensive literature search was performed in PubMed, EMBASE, Cochrane Library, CNKI, Wanfang, and CBM-SinoMed. We constructed resample sets to calculate the standardized prevalence in each study. Multilevel mixed-effects logistic regression was used to estimate the age-specific and sex-specific prevalence. The United Nations Population Division (UNPD) data and regional population data from the fifth and sixth censuses in mainland China were used to estimate and project the national and regional prevalence of osteoporosis.

RESULTS

The standardized prevalence of osteoporosis ranged from 5.04% (2.12~11.34%) to 7.46% (3.13~16.32%) in males aged ≥ 50 years and from 26.28% (15.38~40.40%) to 39.19% (25.74~53.95%) in females aged ≥ 50 years from 1990 to 2050. Moreover, we did not find a significant difference in the standardized prevalence among three geographic regions (Central China, West China, and East China).

CONCLUSION

We found that osteoporosis is a serious public health challenge in mainland China. The findings in our study add insight into the epidemiology of osteoporosis and would be beneficial for the prevention and treatment of osteoporosis in mainland China.

BONE HEALTH, MUSCLE STRENGTH AND LEAN MASS: RELATIONSHIPS AND EXERCISE RECOMMENDATIONS

ABSTRACT Although muscle strength, lean mass and bone mineral content/density (BMC/BMD) are consistently reported as major outcomes of resistance training (RT), there is still no agreement on the RT regimen that is capable of achieving this result in men and women of different ages. This study describes the effects of RT on muscle strength, lean mass and bone mineralization, highlighting the relationships between them and analyzing the effectiveness of the RT protocol. Information searches were conducted in open access online academic libraries, using the BMC/BMD indices combined with muscle strength, body composition, and resistance exercises. The results showed changes in BMC/BMD in 72% of the studies published in the last decade. Among these, 77% recommended loads ≥ 80% 1-RM, 61% involved older individuals (> 60 years) and 61% had planning protocols of between 3 and 5 months (~12-20 weeks). The results also highlight muscle strength as a promising index of variations in BMC/BMD, with a moderate to high level of association (r2>0.5), which are specific for men and women in relation to the body region with best responsiveness. Among the studies published in last decade, about 61% had protocols involving only RT, and of these, 82% observed combined changes in BMC/BMD, body composition and muscle strength. This review therefore concludes that RT is important for improving muscle strength, increasing lean mass (whole-body and regional) and preventing risk factors that could impair the mineral integrity of the bone tissue, in individuals of all ages and sexes. Level of Evidence I; Systematic review of Level I RCTs (and study results were homogenous).

The fat-to-lean mass ratio, a novel anthropometric index, is associated to glucose metabolic disorders

OBJECTIVE

The aim was to evaluate whether the Fat-to-Lean Mass (FyM) ratio is associated to glucose metabolic disorders (GMD).

DESIGN

Cross-sectional population based study.

METHODS

Eligible subjects were healthy men and non-pregnant women with new diagnosis of GMD that were allocated into following groups: 1) Normal Glucose Tolerance (NGT), 2) Diabetes, 3) impaired fasting glucose (IFG) + impaired glucose tolerance (IGT), 4) IGT, and 5) IFG. The FyM index [Total body fat (Kg)/total lean mass (Kg)], and the odds ratio (OR) between FyM index and GMD were estimated.

RESULTS

A total of 875 individuals with average age 41.62 ± 12.3 were enrolled; of them, 645 (73.1%) women and 230 (22.8%) men; 521 (59.5%), 71 (8.1%), 85 (9.7%), 53 (6.0%), and 145 (16.6%) individuals were allocated into groups with NGT, diabetes, IFG + IGT, IGT, and IFG, respectively. The FyM was significantly associated with prediabetes and diabetes in women (OR 4.2; _95%CI 3.0-11.1 and OR = 7.2; _95%CI 2.0-15.2) and men (OR = 2.6; _95%CI 1.1-6.7 and OR = 4.6; _95%CI 1.4-15.1). In the overall population, the OR between FyM index with IGT, IFG, and IFG + IGT was 8.4 (_95%CI 2.6-17.4), 5.2 (_95%CI 2.6-10.6), and 6.1 (_95%CI 1.8-9.5).

CONCLUSION

The FyM index was strongly associated with all categories of GMD.

T Cells in Adipose Tissue in Aging

Similar to obesity, aging is associated with visceral adiposity and insulin resistance. Inflammation in adipose tissue, mainly evidenced by increased accumulation and proinflammatory polarization of T cells and macrophages, has been well-documented in obesity and may contribute to the associated metabolic dysfunctions including insulin resistance. Studies show that increased inflammation, including inflammation in adipose tissue, also occurs in aging, so-called "inflamm-aging." Aging-associated inflammation in adipose tissue has some similarities but also differences compared to obesity-related inflammation. In particular, conventional T cells are elevated in adipose tissue in both obesity and aging and have been implicated in metabolic functions in obesity. However, the changes and also possibly functions of regulatory T cells (Treg) in adipose tissue are different in aging and obesity. In this review, we will summarize recent advances in research on the changes of these immune cells in adipose tissue with aging and obesity and discuss their possible contributions to metabolism and the potential of these immune cells as novel therapeutic targets for prevention and treatment of metabolic diseases associated with aging or obesity.

Relationship between body mass index and renal function deterioration among the Taiwanese chronic kidney disease population

This study investigated the characteristics of patients with different chronic kidney disease (CKD) stages according to various body mass index (BMI) categories and determined the influence of BMI in renal function deterioration. We conducted a multicenter, longitudinal cohort study based on the Epidemiology and Risk Factors Surveillance of CKD project (2008–2013) and National Health Insurance Research Database (2001–2013). A total of 7357 patients with CKD aged 20–85 years from 14 hospitals were included in the study. A higher male sex, diabetes mellitus (DM) and hypertension were noted among overweight and obese CKD patients, while more cancer prevalence was noted among underweight CKD patients. Charlson comorbidity index was significantly higher and correlated with BMI among late CKD patients. Patients with BMI < 18.5 kg/m² exhibited non-significantly higher events of eGFR decline events in both early and late CKD stages than other BMI groups. BMI alone is not a determinant of CKD progression among our Taiwanese CKD patients. Obesity should be re-defined and body weight manipulation should be individualized in CKD patients.

MUSCULAR STRENGTH AND REGIONAL LEAN MASS INFLUENCE BONE MINERAL HEALTH AMONG YOUNG FEMALES

ABSTRACT Introduction: Strength training is able to stimulate bone tissue metabolism by increasing mechanical stress on the skeletal system. However, the direct relationship is not yet well established among younger women, since it is necessary to describe which strength enhancement level is able to produce effective changes in bone integrity. Objectives: This study analyzed the influence of muscle strength on bone mineral content (BMC) and bone mineral density (BMD) among female college students. Methods: Fifteen women (24.9 ± 7.2 years) were assessed for regional and whole-body composition by dual-energy X-ray absorptiometry (DXA). The one-repetition maximum (1-RM) tests were assessed on flat bench press (BP), lat pulldown (LPD), leg curl (LC), knee extension (KE), and 45 degree leg press (45LP). Linear regression analyzed the relationships of BMC/BMD with regional composition and 1-RM test values. Measures of dispersion and error (R2 adj and SEE) were tested, defining a p-value of 0.05. Results: The mean value of whole-body BMC was 1925.6 ± 240.4 g and the BMD was 1.03 ± 0.07 g/cm2. Lean mass (LM) was related to BMC (R2 adj = 0.86, p<0.01, and SEE = 35.6 g) and BMD (R2 adj = 0.46, p<0.01, SEE = 0.13 g) in the lower limbs (LL). The 1-RM tests in BP were associated with BMC and BMD (R2 adj = 0.52, p<0.01, SEE = 21.4 g, and R2 adj = 0.68, p<0.01, SEE = 0.05 g/cm2, respectively) in the upper limbs, while the 1-RM tests in KE were related to BMC and BMD (R2 adj = 0.56, p<0.01. SEE = 62.6 g, and R2 adj = 0.58, p<0.01, SEE = 0.11 g/cm2, respectively) in the lower limbs. Conclusions: Hence, the 1-RM tests for multi-joint exercises are relevant to the regional BMC/BMD, reinforcing the need to include resistance exercises in training routines with the purpose of improving muscular strength and regional lean mass, thereby ensuring a healthy bone mineral mass. Level of Evidence II; Development of diagnostic criteria in consecutive patients (with applied reference ‘‘gold’’ standard).

Muscle strength and regional lean body mass influence on mineral bone health in young male adults

The relationship between muscle strength and bone mineral content (BMC) and bone mineral density (BMD) is supposed from the assumption of the mechanical stress influence on bone tissue metabolism. However, the direct relationship is not well established in younger men, since the enhancement of force able to produce effective changes in bone health, still needs to be further studied. This study aimed to analyze the influence of muscle strength on BMC and BMD in undergraduate students. Thirty six men (24.9 ± 8.6 y/o) were evaluated for regional and whole-body composition by dual energy X-ray absorptiometry (DXA). One repetition maximum tests (1RM) were assessed on flat bench-press (BP), lat-pull down (LPD), leg-curl (LC), knee extension (KE), and leg-press 45° (LP45) exercises. Linear regression modelled the relationships of BMD and BMC to the regional body composition and 1RM values. Measurements of dispersion and error (R²_adj and standard error of estimate (SEE)) were tested, setting ρ at ≤0.05. The BMD mean value for whole-body was 1.12±0.09 g/cm² and BMC attained 2477.9 ± 379.2 g. The regional lean mass (LM) in upper-limbs (UL) (= 6.80±1.21 kg) was related to BMC and BMD for UL (R²_adj = 0.74, p<0.01, SEE = 31.0 g and R²_adj = 0.63, SEE = 0.08 g/cm²), and LM in lower-limbs (LL) (= 19.13±2.50 kg) related to BMC and BMD for LL (R²_adj = 0.68, p<0,01, SEE = 99.3 g and R²_adj = 0.50, SEE = 0.20 g/cm²). The 1RM in BP was related to BMD (R²_adj = 0.51, SEE = 0.09 g/cm²), which was the strongest relationship among values of 1RM for men; but, 1RM on LPD was related to BMC (R²_adj = 0.47, p<0.01, SEE = 44.6 g), and LC was related to both BMC (R²_adj = 0.36, p<0.01, SEE = 142.0 g) and BMD (R²_adj = 0.29, p<0.01, SEE = 0.23 g/cm²). Hence, 1RM for multi-joint exercises is relevant to BMC and BMD in young men, strengthening the relationship between force and LM, and suggesting both to parametrizes bone mineral health.

Different Associations of Trunk and Lower-Body Fat Mass Distribution with Cardiometabolic Risk Factors between Healthy Middle-Aged Men and Women

The aim of this study was to assess whether the gender-specific pattern of fat mass (FM) distribution is related to gender differences in cardiometabolic risk factors. 207 healthy middle-aged Japanese were included in the study. We measured FM in the total body, trunk, and lower-body with dual-energy X-ray absorptiometry (DXA). The percentage of trunk FM (TFM) and lower-body FM (LFM) is noted as %TFM and %LFM, respectively. Other measurements included glucose and insulin during oral glucose tolerance test (OGTT), leptin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and systemic oxidative stress marker. Arterial properties were indicated by cardio-ankle vascular index (CAVI) and intima-media thickness (IMT) of the common carotid artery. The results showed that %TFM is higher whereas %LFM is lower in men than in women and men have a more atherogenic cardiometabolic profile. In both genders, %TFM (%LFM) is related to an unfavorable (favorable) cardiometabolic profile. In particular, the relation between %LFM and OGTT-derived insulin sensitivity index is stronger in women than in men. These findings suggested that in relatively healthy adults, android and gynoid pattern of FM distribution contributes to gender differences in cardiometabolic risk factors.

Imaging of diabetic bone

Diabetes is an important concern in terms of medical and socioeconomic costs; a high risk for low-trauma fractures has been reported in patients with both type 1 and type 2 diabetes. The mechanism involved in the increased fracture risk from diabetes is highly complex and still not entirely understood; obesity could play an important role: recent evidence suggests that the influence of fat on bone is mainly dependent on the pattern of regional fat deposition and that an increased amount of visceral adipose tissue negatively affects skeletal health.Correct and timely individuation of people with high fracture risk is critical for both prevention and treatment: Dual-energy X-ray Absorptiometry (currently the "gold standard" for diagnosis of osteoporosis) underestimates fracture risk in diabetic patients and therefore is not sufficient by itself to investigate bone status. This paper is focused on imaging, covering different modalities involved in the evaluation of skeletal deterioration in diabetes, discussing the limitations of conventional methods and exploring the potential of new tools and recent high-resolution techniques, with the intent to provide interesting insight into pathophysiology and fracture risk.

Development of a Whole-Body Physiologically Based Pharmacokinetic Approach to Assess the Pharmacokinetics of Drugs in Elderly Individuals

Background

Because of the vulnerability and frailty of elderly adults, clinical drug development has traditionally been biased towards young and middle-aged adults. Recent efforts have begun to incorporate data from paediatric investigations. Nevertheless, the elderly often remain underrepresented in clinical trials, even though persons aged 65 years and older receive the majority of drug prescriptions. Consequently, a knowledge gap exists with regard to pharmacokinetic (PK) and pharmacodynamic (PD) responses in elderly subjects, leaving the safety and efficacy of medicines for this population unclear.

Objectives

The goal of this study was to extend a physiologically based pharmacokinetic (PBPK) model for adults to encompass the full course of healthy aging through to the age of 100 years, to support dose selection and improve pharmacotherapy for the elderly age group.

Methods

For parameterization of the PBPK model for healthy aging individuals, the literature was scanned for anthropometric and physiological data, which were consolidated and incorporated into the PBPK software PK-Sim^®. Age-related changes that occur from 65 to 100 years of age were the main focus of this work. For a sound and continuous description of an aging human, data on anatomical and physiological changes ranging from early adulthood to old age were included. The capability of the PBPK approach to predict distribution and elimination of drugs was verified using the test compounds morphine and furosemide, administered intravenously. Both are cleared by a single elimination pathway. PK parameters for the two compounds in younger adults and elderly individuals were obtained from the literature. Matching virtual populations—with regard to age, sex, anthropometric measures and dosage—were generated. Profiles of plasma drug concentrations over time, volume of distribution at steady state (V_ss) values and elimination half-life (t_½) values from the literature were compared with those predicted by PBPK simulations for both younger adults and the elderly.

Results

For most organs, the age-dependent information gathered in the extensive literature analysis was dense. In contrast, with respect to blood flow, the literature study produced only sparse data for several tissues, and in these cases, linear regression was required to capture the entire elderly age range. On the basis of age-informed physiology, the predicted PK profiles described age-associated trends well. The root mean squared prediction error for the prediction of plasma concentrations of furosemide and morphine in the elderly were improved by 32 and 49 %, respectively, by use of age-informed physiology. The majority of the individual V_ss and t_½ values for the two model compounds, furosemide and morphine, were well predicted in the elderly population, except for long furosemide half-lifes.

Conclusion

The results of this study support the feasibility of using a knowledge-driven PBPK aging model that includes the elderly to predict PK alterations throughout the entire course of aging, and thus to optimize drug therapy in elderly individuals. These results indicate that pharmacotherapy and safety-related control of geriatric drug therapy regimens may be greatly facilitated by the information gained from PBPK predictions.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-016-0422-3) contains supplementary material, which is available to authorized users.

Age-related reference curves of volumetric bone density, structure, and biomechanical parameters adjusted for weight and height in a population of healthy women: an HR-pQCT study

In a cross-sectional cohort of 450 healthy women aged 20 to 85 years, data on the density, structure, and strength of the distal radius and tibia were obtained using high-resolution peripheral quantitative computed tomography (HR-pQCT) and were adjusted for age, weight, and height. Age-dependent patterns of change differed between the sites and between the trabecular and cortical compartments. In postmenopausal women, the trabecular bone remained relatively stable at the distal tibia, but the cortical compartment changed significantly. Cortical porosity exhibited a very weak correlation with stiffness.

INTRODUCTION

The aim of this study is to provide information on age-related, weight-related, and height-related changes in the volumetric bone mineral density (vBMD), structure, and biomechanical parameters of the cortical and trabecular compartments in a healthy female population using HR-pQCT.

METHODS

For a cross-sectional Brazilian cohort of 450 women aged 20 to 85 years, age-related reference curves of the vBMD, structure, and biomechanical parameters of the distal radius (DR) and distal tibia (DT) were constructed and adjusted for weight and height, and comparisons between premenopausal and postmenopausal women were performed.

RESULTS

Reference curves were obtained for all parameters. At the DR, age-related changes varied from -8.68% (cortical thickness [Ct.Th]) to 26.7% (trabecular separation [Tb.Sp]). At the DT, the changes varied from -12.4% (Ct.Th) to 26.3% (Tb.Sp). Cortical porosity (Ct.Po) exhibited the largest percent changes: 342.2% at the DR and 381.5% at the DT. In premenopausal women, Ct.Th remained constant; in postmenopausal women, structural trabecular parameters (trabecular number (Tb.N), trabecular thickness (Tb.Th), Tb.Sp) did not change, whereas cortical parameters and stiffness were significantly altered. Cortical vBMD showed the greatest absolute decrease at both sites, and the slopes were highly negative after menopause. Pearson correlations between stiffness (S) and HR-pCT parameters revealed a significant correlation between the densities and structures of the trabecular and cortical compartments. A weak correlation was observed between S and Ct.Po (DR r = -0.162, DT r = -0.273; p < 0.05).

CONCLUSIONS

These data provide reference curves from healthy women and demonstrate that density and structural and biomechanical parameters differ between the radius and tibia and between the trabecular and cortical compartments. In postmenopausal women, the trabecular bone remained relatively stable at the tibia site, whereas the cortical compartment changed significantly.

A New Equation to Estimate Muscle Mass from Creatinine and Cystatin C

Background

With evaluation for physical performance, measuring muscle mass is an important step in detecting sarcopenia. However, there are no methods to estimate muscle mass from blood sampling.

Methods

To develop a new equation to estimate total-body muscle mass with serum creatinine and cystatin C level, we designed a cross-sectional study with separate derivation and validation cohorts. Total body muscle mass and fat mass were measured using dual-energy x-ray absorptiometry (DXA) in 214 adults aged 25 to 84 years who underwent physical checkups from 2010 to 2013 in a single tertiary hospital. Serum creatinine and cystatin C levels were also examined.

Results

Serum creatinine was correlated with muscle mass (P < .001), and serum cystatin C was correlated with body fat mass (P < .001) after adjusting glomerular filtration rate (GFR). After eliminating GFR, an equation to estimate total-body muscle mass was generated and coefficients were calculated in the derivation cohort. There was an agreement between muscle mass calculated by the novel equation and measured by DXA in both the derivation and validation cohort (P < .001, adjusted R² = 0.829, β = 0.95, P < .001, adjusted R² = 0.856, β = 1.03, respectively).

Conclusion

The new equation based on serum creatinine and cystatin C levels can be used to estimate total-body muscle mass.

Does Low Body Mass Index Matter? Relationship between Body Mass Index and Subjective Well-Being among Long-Lived Women over 95 Years of Age

OBJECTIVES

To examine the relationship between body mass index (BMI) and subjective well-being (SWB) among long-lived women over 95 years of age and evaluate whether this relationship is mediated by functional ability.

DESIGN

Retrospective cohort study.

SETTING

Data from the Rugao longevity cohort, a population-based study in Rugao, China.

PARTICIPANTS

A sample of 342 long-lived women (mean age 97.4 ± 2.1, range 95-107) whose SWB and other covariates were available were included in this study.

MEASUREMENTS

BMI was calculated as weight in kilograms divided by height in meters-squared (kg/m(2)). SWB was measured by life satisfaction (LS), positive affect (PA), negative affect (NA) and affect balance (AB). Functional ability was assessed by the Katz Index of Activities of Daily Living (ADL).

RESULTS

According to BMI classification standards for China, the underweight group had lower levels of LS than the normal and overweight groups (28.62 vs. 30.51 and 31.57, respectively; p<.05). Correlation analysis showed that BMI was significantly related to LS (r = 0.166, p<.01). The strength of the BMI and LS association was diminished when ADL was included in the general linear regression models. Mediation analysis revealed that ADL mediated this relationship (effect size = 22.6%). We did not observe significant associations of BMI with other SWB components (PA, NA, and AB).

CONCLUSION

For long-lived women, low BMI, rather than elevated BMI, is an indicator of poor psychological well-being. The findings call for public health awareness about low body weight in long-lived women, especially in those with physical disabilities when focusing on quality of life.

The Sexual Dimorphism of Lipid Kinetics in Humans

In addition to the obvious differences in body shape, there are substantial differences in lipid metabolism between men and women. These differences include how dietary fatty acids are handled, the secretion and clearance of very low-density lipoprotein-triglycerides, the release rates of free fatty acids (FFA) from adipose tissue relative to energy needs, and the removal of FFA from the circulation, including the storage of FFA into adipose tissue via the direct uptake process. We will review what is known about these processes and how they may contribute to the sexual dimorphism of body fat distribution.

Adipose, bone and muscle tissues as new endocrine organs: role of reciprocal regulation for osteoporosis and obesity development

The belief that obesity is protective against osteoporosis has recently been revised. In fact, the latest epidemiologic and clinical studies show that a high level of fat mass, but also reduced muscle mass, might be a risk factor for osteoporosis and fragility fractures. Furthermore, increasing evidence seems to indicate that different components such as myokines, adipokines and growth factors, released by both fat and muscle tissues, could play a key role in the regulation of skeletal health and in low bone mineral density and, thus, in osteoporosis development. This review considers old and recent data in the literature to further evaluate the relationship between fat, bone and muscle tissue.

Aging and the muscle-bone relationship

Aging-induced declines in muscle size and quality are thought to contribute to catabolic alterations in bone, but changes in bone with age also profoundly alter its response to muscle-derived stimuli. This review provides an overview of some of the alterations that occur in muscle and bone with aging, and discusses the cellular and molecular mechanisms that may impact these age-associated changes.

Changes in adipose tissue macrophages and T cells during aging

Adipose tissue historically was believed to be an inert tissue, functioning primarily in the storage of energy and thermal homeostasis. However, recent discoveries point toward a critical role for adipocytes in endocrine function as well as immune regulation. Excess body fat, accumulated through aging and/or a calorie-rich diet, is associated with many chronic metabolic and inflammatory diseases. Within the stromal vascular fraction of adipose tissue, macrophages and T cells accumulate with increasing tissue mass, secreting pro- or anti-inflammatory cytokines. In this review we discuss the current understanding of immune cell function in both diet-induced and age-related obesity. In both models of obesity, the classically activated, pro-inflammatory (M1) subtype takes precedence over the alternatively activated, anti-inflammatory (M2) macrophages, causing tissue necrosis and releasing pro-inflammatory cytokines like interleukin-6. Other distinct adipose tissue macrophage subtypes have been identified by surface marker expression and their functions characterized. Adipose tissue T cell recruitment to adipose tissue is also different between aging- and diet-induced obesity. Under both conditions, T cells exhibit restricted T-cell receptor diversity and produce higher levels of pro-inflammatory signals like interferon-γ and granzyme B relative to young or healthy mice. However, numbers of regulatory T cells are dramatically different between the 2 models of obesity. Taken together, these findings suggest models of age- and diet-induced obesity may be more distinct than previously thought, with many questions yet to be resolved in this multidimensional disease.

The obesity pattern of idiopathic intracranial hypertension in men

BACKGROUND

Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a disorder of unknown etiology, predominantly affecting obese women of childbearing age. IIH is uncommon in men, with a reported female-to-male ratio of 8:1. The pathogenesis of IIH is poorly understood. Several mechanisms have been suggested, but no one mechanism has been able to account for all manifestations of the disease. This research aims to characterize the obesity phenotype(s) of men with IIH in order to find potential inducers for this disease.

METHODS

This is a cross-sectional study based on subjects' medical records. It compared anthropometric parameters between 22 men with IIH, 60 healthy men, and 44 females with IIH. One-way analysis with age and body mass index included as covariates was applied for the assessment of the difference in fat distribution among the three groups.

RESULTS

No significant differences were observed between the male IIH cohort and healthy males for age, BMI, and waist measurements, whereas hip circumference was significantly larger in the IIH cohort (114 ± 13 vs. 104 ± 16 cm; respectively, p < 0.001). Consequently, waist-to-hip ratio (WHR) was significantly lower in the male IIH cohort (0.88 ± 0.08 vs. 0.95 ± 0.12; p < 0.001). While no significant differences were observed for age and hip measurements between male IIH and female IIH cohorts, waist circumference and waist-to-hip ratio (WHR) were significantly larger in the male cohort (102 ± 19 cm vs. 95 ± 13 cm, p < 0.001; 0.88 ± 0.08 vs. 0.78 ± 0.06, p < 0.001, respectively). All these results maintained after adjustment for age and BMI.

CONCLUSIONS

This is the first report of body fat distribution patterns in men with IIH. Whereas male IIH have larger central fat deposition than female IIH patients, abdominal fatness is less accentuated in IIH men compared to normal obese men. The later observation is in agreement with similar results regarding female IIH patients. We believe that these findings justify further investigation into the involvement of various fat depots in the pathogenesis of IIH in men and women alike.

Does Muscle Mass Affect Running Times in Male Long-distance Master Runners?

Purpose

The aim of the present study was to investigate associations between skeletal muscle mass, body fat and training characteristics with running times in master athletes (age > 35 years) in half-marathon, marathon and ultra-marathon.

Methods

We compared skeletal muscle mass, body fat and training characteristics in master half-marathoners (n=103), master marathoners (n=91) and master ultra-marathoners (n=155) and investigated associations between body composition and training characteristics with race times using bi- and multi-variate analyses.

Results

After multi-variate analysis, body fat was related to half-marathon (β=0.9, P=0.0003), marathon (β=2.2, P<0.0001), and ultra-marathon (β=10.5, P<0.0001) race times. In master half-marathoners (β=-4.3, P<0.0001) and master marathoners (β=-11.9, P<0.0001), speed during training was related to race times. In master ultra-marathoners, however, weekly running kilometers (β=-1.6, P<0.0001) were related to running times.

Conclusions

To summarize, body fat and training characteristics, not skeletal muscle mass, were associated with running times in master half-marathoners, master marathoners, and master ultra-marathoners. Master half-marathoners and master marathoners rather rely on a high running speed during training whereas master ultra-marathoners rely on a high running volume during training. The common opinion that skeletal muscle mass affects running performance in master runners needs to be questioned.

Body composition, bone mineral density and fractures in late postmenopausal women with polycystic ovary syndrome - a long-term follow-up study

OBJECTIVE

Hyperandrogenism is one of the characteristic features of the polycystic ovary syndrome (PCOS). Androgens are important for bone mass. Studies on bone mineral density (BMD) and fractures in postmenopausal women with PCOS are lacking. The aim of this study was to investigate whether postmenopausal women with PCOS differ from controls regarding body composition, BMD and prevalence of fractures, and to compare women with PCOS with controls regarding correlations between total BMD and sex hormones.

DESIGN

A prospective 21-year follow-up study. Anthropometry, hormonal measurements and questionnaires were performed in 1987 and in 2008. Fractures were X-ray-verified. BMD measurements were taken in 1992, using single-photon absorptiometry (SPA), and in 2008, using dual-energy X-ray absorptiometry (DXA), to also enable measurements of body composition.

PATIENTS

Twenty-five women with PCOS (Rotterdam criteria), aged 61-78 years, and 68 randomly allocated age-matched controls.

MEASUREMENTS

Body composition, BMD, fractures and sex steroids.

RESULTS

At follow-up, the postmenopausal women with PCOS maintained a higher free androgen index (FAI), but had similar body fat, lean mass and BMD compared with controls. The hip circumference increased only in women with PCOS (P < 0·01), during follow-up. The fracture incidence was similar to that of controls (56% vs 41%, ns). In the controls, total BMD was positively correlated with oestradiol (R = 0·322, P < 0·01) and FAI (R = 0·307, P < 0·05) and negatively correlated with SHBG (R = -0·429, P < 0·001), but not in the women with PCOS.

CONCLUSIONS

Postmenopausal women with PCOS with persistently higher FAI had similar muscle mass, BMD and fracture incidence as controls during this long-term follow-up.

Sarcopenic obesity and cognitive functioning: the mediating roles of insulin resistance and inflammation?

This study examined the influence of insulin resistance and inflammation on the association between body composition and cognitive performance in older adults, aged 60–69 and aged 70 and older. Subjects included 1127 adults from NHANES 1999–2002. Body composition was categorized based on measurements of muscle mass and waist circumference as sarcopenic nonobese, nonsarcopenic obese, sarcopenic obese, and normal. Using OLS regression models, our findings suggest body composition is not associated with cognitive functioning in adults ages 60–69; however, for adults aged 70 and over, sarcopenia and obesity, either independently or concurrently, were associated with worse cognitive functioning relative to non-sarcopenic non-obese older adults. Furthermore, insulin resistance accounted for a significant proportion of the relationship between cognitive performance and obesity, with or without sarcopenia. Additionally, although high CRP was significantly associated with poorer cognitive functioning in adults ages 60–69, it did not influence the association between body composition and cognitive performance. This study provides evidence that age-related physiological maladaptations, such as metabolic deregulation, which are associated with abdominal fat, may simultaneously contribute to lower cognition and muscle mass, reflecting a degradation of multiple physiological systems.

Effects of resistance or aerobic exercise training on total and regional body composition in sedentary overweight middle-aged adults

The purpose of this study was to examine the effects of 10 weeks of aerobic endurance training (AET), resistance exercise training (RET), or a control (CON) condition on absolute and relative fat mass (FM) or fat-free mass (FFM) in the total body (TB) and regions of interest (ROIs) of sedentary overweight middle-aged males and females. Following prescreening, 102 subjects underwent anthropometric measurements, dual-energy X-ray absorptiometry, and strength and aerobic exercise testing. Randomized subjects (male RET, n = 16; female RET, n = 19; male AET, n = 16; and female AET, n = 25) completed supervised and periodized exercise programs (AET, 30-50 min cycling at 70%-75% maximal heart rate; RET, 2-4 sets × 8-10 repetitions of 5-7 exercises at 70%-75% 1 repetition maximum) or a nonexercising control condition (male CON, n = 13 and female CON, n = 13). Changes in absolute and relative TB-FM and TB-FFM and ROI-FM and ROI-FFM were determined. At baseline, and although matched for age and body mass index, males had greater strength, aerobic fitness, body mass, absolute and relative TB-FFM and ROI-FFM, but reduced absolute and relative TB-FM and ROI-FM, compared with females (p < 0.05). After training, both female exercise groups showed equivalent or greater relative improvements in strength and aerobic fitness than did the male exercise groups (p < 0.05); however, the male exercise groups increased TB-FFM and reduced TB-FM more than did the female exercise groups (p < 0.05). Male AET altered absolute FM more than male RET altered absolute FFM, thus resulting in a greater enhancement of relative FFM. Despite equivalent or greater responses to RET or AET by female subjects, the corresponding respective increases in FFM or reductions in FM were lower than those in males, indicating that a biased dose-response relationship exists between sexes following 10 weeks of exercise training.

Aging is associated with an increase in T cells and inflammatory macrophages in visceral adipose tissue

Age-related adiposity has been linked to chronic inflammatory diseases in late life. To date, the studies on adipose tissue leukocytes and aging have not taken into account the heterogeneity of adipose tissue macrophages (ATMs), nor have they examined how age impacts other leukocytes such as T cells in fat. Therefore, we have performed a detailed examination of ATM subtypes in young and old mice using state of the art techniques. Our results demonstrate qualitative changes in ATMs with aging that generate a decrease in resident type 2 (M2) ATMs. The profile of ATMs in old fat shifts toward a proinflammatory environment with increased numbers of CD206(-)CD11c(-) (double-negative) ATMs. The mechanism of this aging-induced shift in the phenotypic profile of ATMs was found to be related to a decrease in peroxisome proliferator-activated receptor-γ expression in ATMs and alterations in chemokine/chemokine receptor expression profiles. Furthermore, we have revealed a profound and unexpected expansion of adipose tissue T cells in visceral fat with aging that includes a significant induction of regulatory T cells in fat. Our findings demonstrate a unique inflammatory cell signature in the physiologic context of aging adipose tissue that differs from those induced in setting of diet-induced obesity.

A proposed method for the evaluation of body fat in Japanese adults that predicts obesity

The present study was designed to develop a simple predictive equation for the percent body fat (%BF) in Japanese adults based on variables collected during health examinations. We hypothesized that a benchmark for defining metabolic syndrome and obesity could be based on %BF, which was measured by underwater weighing (UW) as a gold standard for body composition assessment. Thus, we developed a predictive equation for %BF derived from UW that may contribute to the assessment of obesity status, characterized by an excess accumulation of visceral or subcutaneous fat. The subjects were 810 Japanese participants (283 men, 527 women, ages 18-59 years). Anthropometric variables, including height, weight, 7 circumferences, and 8 skinfold thicknesses, were measured. The developed predictive equation was as follows: %BF = 10.558 × sex (1 for men; 2 for women) + 0.069 × age + 0.667 × body mass index + 0.314 × abdominal circumference - 35.881.The coefficient of determination (r(2)) was 0.69. The predicted %BF derived from this equation was highly correlated with UW-measured values and did not show underestimation or overestimation in either sex. These data suggested that this predictive equation for %BF can be used for all Japanese adults and does not require the use of medical equipment and special measurement techniques. By combining the equation for %BF developed in this study with a %BF cutoff value of metabolic syndrome and obesity (>25.0% in men and >30.0% in women), all Japanese adults can easily and conveniently assess obesity status.

Weight change and cognitive function: findings from the Women's Health Initiative Study of Cognitive Aging

Although studies exploring relationships between obesity and cognitive impairment in the elderly are conflicting, literature suggests that overweight and obesity may be protective against cognitive impairment and dementia in older women. We examine the associations between changes in weight and waist circumference (WC) with global and domain-specific cognitive function in a large, well-defined cohort of 2,283 older, postmenopausal women (aged 65-79) prospectively followed through the Women's Health Initiative (WHI) Study of Cognitive Aging (WHISCA). We assessed the associations between changes in weight and WC collected up to 5 years before WHISCA enrollment and mean levels of global and domain-specific cognitive performance across an average of 5.4 years of subsequent follow-up. There was a lack of associations between weight and cognition in women who remained stable or gained weight. The only significant relationships observed were in association with weight loss (P ≤ 0.05), most likely signaling incipient disease. Moreover, cognition was not related to changes in WC. Relationships were largely independent of initial BMI, self-reported caloric intake or dieting. The lack of associations between weight gain and cognition in women is consistent with the existing literature.

Association between sleep quality and body mass index among Chinese nonagenarians/centenarians

We examined the individual association between body mass index (BMI) and sleep quality among the very elderly. The present study analyzed data from survey that was conducted on all residents aged 90 years or more in a district, there were 2,311,709 inhabitants in 2005. Subjects were divided into four groups according to quartile of BMI (<16.6, 16.6-18.9, 18.9-21.1, >21.1 kg/m(2)) and according to classification criteria of underweight, normal weight, overweight, and obesity in BMI (<18.5, 18.5-23.0, 23.0-27.5, >27.5 kg/m(2)), respectively. Sleep quality was measured using The Pittsburgh Sleep Quality Index (PSQI). Sleep quality included quality classification and scores, sleep duration, sleep latency, and sleep efficiency. The subjects included in the statistical analysis were 216 men and 444 women. According to quartile of BMI or classification criteria of underweight, normal weight, overweight, and obesity in BMI, none of the differences in sleep quality scores, sleep latency, sleep duration, sleep efficiency percentage, and prevalence of poor sleep quality was significant among different BMI groups. The difference in BMI between subjects with good and poor sleep quality was non-significant. Unadjusted and adjusted multiple logistic regression showed that none of the BMI groups had a function of decreasing the risk for poor quality. Among longevity Chinese, there is no association between BMI and sleep quality.

Consistency of fat mass--fat-free mass relationship across ethnicity and sex groups

The model developed by Forbes (1987) of how body fat mass (FM) and fat-free mass (FFM) change during periods of weight loss or gain (Δ body weight (BW)) assumed that they change in relationship to a constant C = 10·4, where ΔFFM/ΔBW = 10·4/(10·4+FM). Forbes derived C based on aggregated, cross-sectional data from a small sample of women. The objective of the present study was to reanalyse the relationship described by Forbes and to explore whether this relationship is consistent across ethnicity and sex groups using cross-sectional data from a large sample of white and African-American men and women. Baseline data from white and African-American men and women aged 18-60 years, who participated in a clinical study at the Pennington Biomedical Research Center since 2001 and who underwent dual-energy X-ray absorptiometry scans, were available for analysis. To overcome differences in BMI distributions among the ethnicity-by-sex groups, a stratified random sample of participants was selected within each group such that numbers in each BMI category ( < 25, 25-29·9, 30-34·9, 35-39·9, 40+ kg/m2) were proportional to those within the group with the smallest sample size, yielding a sample of 1953 individuals. Linear regression models assessed the FM-FFM relationship across the four ethnicity-by-sex groups. The FM-FFM relationship varied little by ethnicity (P = 0·57) or by sex (P = 0·26). The constant describing the FM-FFM relationship was estimated to be 9·7 (95 % CI 9·0, 10·3). In conclusion, results from our large, biethnic sample of men and women found a FM-FFM relationship very close to that originally described by Forbes, absent of significant variability by ethnicity or sex.

The relationship between BMI and percent body fat, measured by bioelectrical impedance, in a large adult sample is curvilinear and influenced by age and sex

OBJECTIVE

The study aimed to establish the effects of age, gender and age-gender interactions on BMI-% fat relationships over a wide range of BMI and age. It also aimed to examine controversies regarding linear or curvilinear BMI-% fat relationships.

METHODS

Body composition was measured using validated bio-impedance equipment (Bodystat) in a large self-selected sample of 23,627 UK adults aged 18-99 (99% ≤70) years, of which 11,582 were males with a mean BMI of 26.3±4.7 (sd) kg/m(2), and 12,044 females, with a mean BMI of 25.7±5.1 kg/m(2). Multiple regression analysis was used.

RESULTS

BMI progressively increased with age in women and plateaued between 40 and 70 years in men. At a fixed BMI, body fat mass increased with age (1.9 kg/decade), as did % fat (1.1-1.4% per decade). The relationship between BMI and % fat was found to be curvilinear (quadratic) rather than linear, with a weaker association at lower BMI. There was also a small but significant age-gender interaction.

CONCLUSION

The association between BMI and % body fat is not strong, particularly in the desirable BMI range, is curvilinear rather than linear, and is affected by age.

Idiopathic intracranial hypertension is associated with lower body adiposity

OBJECTIVE

To characterize the obesity phenotype(s) in patients with idiopathic intracranial hypertension (IIH).

DESIGN

Database study.

PARTICIPANTS

We studied 44 consecutive patients with IIH, in addition to 184 women attending the obesity clinic of the same medical center and 199 obese women participating in the first Israeli national survey on health and nutrition conducted in 1999 and 2000.

METHODS

Anthropometric parameters were compared with those of 2 control groups of the same age range.

MAIN OUTCOME MEASURES

Weight, height, and waist and hip circumference were measured.

RESULTS

Forty subjects, comprising 91.0% of this cohort, were either overweight (body mass index, 25.0-29.9 kg/m(2)) or obese (body mass index > or = 30 kg/m2). Mean waist circumference was 95.3 cm for IIH, 99.8 cm for the national survey, and 114.5 cm for the obesity clinic cohort (P<0.001), whereas hip circumference was 121 cm for IIH, 118.4 cm for the national survey, and 125.8 cm (P = not significant) for the obesity clinic cohorts. Waist-to-hip ratio, a descriptive measure of body fat distribution approximately reflecting upper to lower body fat ratio, was 0.79 in the patients with IIH, 0.84 in the national survey group, and 0.91 in the obesity clinic cohort (P<0.001; all comparisons were adjusted for age and body mass index).

CONCLUSIONS

In IIH, fat tends to preferentially accumulate in the lower body relative to other obese women of the same range. Whereas most complications of obesity, such as hypertension, diabetes, dyslipidemia, and the metabolic syndrome, are linked to upper body adiposity, IIH may represent a unique condition potentially induced by nonvisceral fat-related mechanisms.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Reciprocal relations of subcutaneous and visceral fat to bone structure and strength

CONTEXT

Increased body fat is a risk factor for cardiovascular and metabolic disease, yet it is uncertain whether obesity protects against osteoporosis or adiposity is harmful to bone.

OBJECTIVE

The aim of the study was to assess whether the pattern of adipose tissue deposition influences bone structure and strength.

DESIGN

The relations between sc and visceral adiposity and the cross-sectional dimensions and polar and principal moments of the femur in 100 healthy women ages 15 to 25 years were obtained using computed tomography.

RESULTS

Multiple linear regression analyses indicated that, after adjusting for leg length and thigh musculature, both sc and visceral fat had strong and independent associations with femoral cross-sectional area, cortical bone area, principal moment maximum, principal moment minimum, and polar moment (all P values < 0.03). However, whereas sc fat had a positive predictive value with all femoral bone phenotypes, a similar but negative effect was observed between visceral fat and these measures (all P values < 0.01).

CONCLUSIONS

We found that visceral and sc fat have opposite effects on the appendicular skeleton; whereas sc fat is beneficial to bone structure and strength, visceral fat serves as an unique pathogenic fat depot.

Low-fat dairy intake and body weight and composition changes in college students

Dairy calcium may help prevent excess weight gain and obesity when consumed in adequate amounts (three or more servings per day) and combined with energy balance. This prospective cohort study was conducted to evaluate dairy intake and examine the association between low-fat dairy intake and body weight and composition changes in college students. Seventy-six college students (65 women and 11 men; mean age+/-standard error [SE]=19.2+/-0.2 years) completed 7-day food records, body height (cm), weight (kg), and waist circumference (cm) measurements twice (September 2004 and April 2005). Percentage of truncal fat and percentage of total body fat were measured by dual-energy x-ray absorptiometry. One-way multivariate analysis of covariance was conducted. Overall (mean+/-SE) total dairy (1.4+/-0.1 servings/day), low-fat dairy (0.5+/-0.1 servings/day), and calcium (815+/-41 mg/day) intakes were low. Subjects who consumed a higher amount of low-fat dairy products (mean+/-SE=0.8+/-0.1 servings/day) had better diet quality, gained less body weight, and had reductions in waist circumference, percentage truncal fat, and percentage total body fat compared to those with lower intake (mean+/-SE=0.1+/-0.0 servings/day). Low-fat dairy intake may be associated with better diet quality and weight management in college students. Nutrition interventions in young adults should promote low-fat dairy intake as part of an overall healthful lifestyle.