Characteristics of body fat, body fat percentage and other body composition for Koreans from KNHANES IV

Hyperglycemia and Central Obesity Disrupt Conditioned Pain Modulation: A Single-Blind Crossover Randomized Controlled Trial

Hyperglycemia and high adiposity are risk factors for pain in diabetes. To clarify these links with pain, the effects of a glucose load on sensory detection, pain sensitivity, conditioned pain modulation (primary aims), and autonomic and endothelial functions (secondary aims) were examined in 64 pain-free participants: 22 with normal adiposity (determined by dual-energy X-ray absorptiometry), 29 with high adiposity, and 13 with combined high adiposity and elevated glycated hemoglobin (HbA1c; including prediabetes and type 2 diabetes). Participants ingested either 37.5 g glucose or 200 mg sucralose (taste-matched) in the first session and crossed over to the other substance in the second session 1 month later. At baseline, painful temple cooling (the conditioning stimulus) inhibited pressure- and heat-pain in the ipsilateral arm (the test stimuli) immediately after cooling ceased (partial η2's > .32). Glucose ingestion weakened pressure-pain inhibition irrespective of HbA1c levels (partial η2 = .11). However, a larger reduction in pressure-pain inhibition after ingesting glucose was associated with a higher waist/hip ratio (r = .31), suggesting a role of central obesity. Heat-pain inhibition was absent at baseline in unmedicated participants with elevated HbA1c, and these participants reported more occlusion-induced pain after ingesting glucose (partial η2's > .17). Glucose ingestion interfered with parasympathetic activity in all participants (partial η2 = .11) but did not affect endothelial function (measured by reactive hyperemia) or alter other sensations (eg, feet vibration detection). The disruptive effect of hyperglycemia on conditioned pain modulation increases in line with central obesity, which might facilitate pain in diabetes. PERSPECTIVE: Ingesting 37.5 g glucose (approximately 350 mL soft drink) interfered with pain modulation in pain-free adults with normal adiposity or with combined high adiposity and HbA1c levels. The interference was stronger alongside increasing central obesity, suggesting that controlling blood glucose and body fat mass might help preserve pain modulation.

Normative Values and Anthropometric Prediction Models for Lean Mass and Fat Mass in the Northeastern Thai Population

Background: Data on reference values for lean mass (LM) and fat mass (FM) in the Southeast Asian populations are currently lacking. Therefore, we aimed to estimate the normative values and generate anthropometric prediction models for LM and FM in the Thai population. Methods: Consecutive community-dwelling individuals aged 20-90 years were recruited from Srinagarind Hospital, Khon Kaen, Thailand, between 2010 and 2015. LM and FM were measured using dual energy X-ray absorptiometry. Age and sex stratified percentile of LM and FM were presented. Anthropometric prediction models for LM and FM were developed by using linear regression to generate competing models. Results: A total of 832 individuals (334 males and 498 females) were included in the study. The mean ± SD age, LM, and FM were 50.0 ± 16.2 years, 38.9 ± 8.0 kg, and 15.5 ± 7.7 kg, respectively. LM decreased with age from 49.4 kg in 20-29 years group to 42.3 kg in ≥70 years group in male and 34.6 kg in 30-39 years group to 30.8 kg in ≥70 years group in females. FM has an inverse U-shaped association with age, which peaked at 11.9 kg in 60-69 years group in males and 20.7 kg in 50-59 years group in females. Among the various anthropometric models, the models incorporating age, sex, weight, and height were considered the best fit for predicting both LM and FM. Conclusion: In the Thai population, peak LM was reached during early adulthood and decline with age, whereas FM showed an inverse U-shaped association with age. The prediction models incorporating age, sex, weight, and height were proposed as practical tools for assessing LM and FM in clinical practice.

The Evolving Landscape of Sarcopenia in Asia: A Systematic review and meta-analysis following the 2019 Asian working group for sarcopenia (AWGS) diagnostic criteria

BACKGROUND

Sarcopenia, characterized by age-related loss of muscle mass and function, poses a significant public health concern, particularly in Asia's rapidly aging population. This systematic review and meta-analysis aimed to evaluate the current epidemiology of sarcopenia in Asia using the 2019 Asian Working Group for Sarcopenia (AWGS) diagnostic criteria.

METHODS

Databases including PubMed, Embase, Web of Science, and Cochrane were systematically searched for studies published until December 7, 2023, involving older adults aged ≥ 60 years diagnosed with sarcopenia using the 2019 AWGS criteria in Asia. Study quality was assessed, and meta-analyses were conducted to estimate the pooled prevalence of sarcopenia, possible sarcopenia, and severe sarcopenia.

RESULTS

A total of 140 studies, collectively involving 156,325 participants (67.1 % community-dwelling older adults with the minimum age for participant inclusion ranging from 60 to 80 years) from various Asian countries, were included. The overall prevalence of sarcopenia among community-dwelling older adults was 16.5 % (95 % CI: 14.7 %-18.4 %). Notably, the prevalence of possible sarcopenia was higher at 28.7 % (95 % CI: 22.0 %-36.5 %), while severe sarcopenia had a lower prevalence of 4.4 % (95 % CI: 3.3 %-5.8 %). Subgroup analyses revealed variations in sarcopenia prevalence based on diagnostic modalities, ranging from 7.5 % (95 % CI: 6.0 %-9.4 %) for assessments using bioelectrical impedance analysis, handgrip strength, gait speed, chair stand and short physical performance battery, to 20.8 % (95 % CI: 18.9 %-23.0 %) when using dual-energy X-ray absorptiometry coupled with muscle strength and physical performance measures.

CONCLUSION

This comprehensive systematic review and meta-analysis highlights the substantial burden of sarcopenia among older adults in Asia, underscoring the need for early identification and intervention strategies to mitigate its adverse consequences on public health.

Usefulness of the mini nutritional assessment short-form for evaluating nutritional status in patients with nontuberculous mycobacterial pulmonary disease: a prospective cross-sectional study

BACKGROUND

Although the Mini Nutritional Assessment (MNA) is recognized as a useful tool for evaluating nutritional status in patients with various diseases, its applicability in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) remains undetermined.

METHODS

We designed a prospective cross-sectional study to investigate whether the MNA Short-Form (MNA-SF) score can serve as a screening tool to assess the nutritional status of patients with NTM-PD. The MNA-SF was conducted upon patient enrollment, and correlation analyses were performed to compare MNA-SF scores with other nutritional measurements and disease severity. Multivariable logistic regression analyses were conducted to evaluate the association between MNA-SF scores and NTM-PD severity.

RESULTS

The 194 patients with NTM-PD included in the analysis had a median age of 65.0 (59.0-69.0) years; 59.3% (n = 115) had low MNA-SF scores (< 12). The low MNA-SF group exhibited a lower body mass index (19.7 vs. 22.4 kg/m2, p < 0.001) and fat-free mass index (14.7 vs. 15.6 kg/m2, p < 0.001) than the normal MNA-SF group, as well as higher incidences of sarcopenia (20.0% vs. 6.3%, p = 0.008) and adipopenia (35.7% vs. 5.1%, p < 0.001). However, no significant differences in calorie and protein intakes were observed between the two groups. Low MNA-SF scores were associated with radiographic severity (adjusted odds ratio 2.72, 95% confidence interval 1.38-5.36) but not with forced vital capacity.

CONCLUSIONS

The MNA-SF can effectively assess the nutritional status of patients with NTM-PD and can serve as an important clinical indicator in NTM-PD where treatment timing is determined by clinical judgment.

Cutoff values for appendicular skeletal muscle mass using dual-energy x-ray absorptiometry in a reference group of Turkish adults

BACKGROUND

The aim of this study is to determine cutoff values for different appendicular skeletal muscle mass index (ASMI) methods measured by dual-energy x-ray absorptiometry (DXA) in a reference group of the Turkish population.

METHODS

Body composition analyses were performed with DXA, and appendicular skeletal muscle mass (ASM) was adjusted to body size as ASMI using height squared (ASM/ht2), weight (ASM/wt), and body mass index (BMI) (ASM/BMI). Sex-specific cutoff values were obtained as 1 and 2 standard deviations (SDs) below the mean values of ASM/ht2, ASM/wt, and ASM/BMI.

RESULTS

A total of 207 (106 women and 101 men) healthy adults were enrolled. Sex-specific cutoff values based on 1 SD below the mean values of ASM, ASM/ht2, ASM/BMI, and ASM/wt were 14.44, 5.45, 0.61, and 24.07 in women and 22.63, 7.22, 0.90, and 29.04 in men, respectively; 2 SDs below the mean values of ASM, ASM/ht2, ASM/BMI, and ASM/wt were 11.96, 4.65, 0.51, and 21.75 in women and 19.26, 6.40, 0.78, and 26.55 in men, respectively. ASM, ASM/BMI, ASM/ht2, and ASM/wt were statistically significant positively correlated with handgrip strength (r = 0.81, r = 0.78, r = 0.73, and r = 0.67, respectively; P < 0.001).

CONCLUSION

In this study, ASM/BMI was found to be the most suitable ASM adjustment method to predict muscle strength.

Age- and sex-related trends in body composition among Beijing adults aged 20-60 years: a cross-sectional study

BACKGROUND

Obesity is the most serious global epidemic and body composition is the main indicator to evaluate obesity. This study aimed to investigate the changing trends of body composition by age and gender in Beijing adults aged 20-60 years and explore the distribution of obesity rates in different age groups of both sexes under different evaluation criteria.

METHODS

A total of 24,948 adults aged 20-60 years in Beijing, including 10,225 males and 14,192 females, were included, divided into four age groups (20-29, 30-39, 40-49, and ≥ 50 years) with each decade of age as an age group. Body composition indicators (BMI, fat mass, BF%, muscle mass, visceral fat area, and WHR) were measured in all subjects.

RESULTS

BMI and total fat mass peaked in males aged 40-49 years (BMI = 25.75 kg/m2, total fat mass = 17.70 kg). Female BMI, fat mass and BF% all increased significantly with age (p < 0.01). Total muscle peaked in males aged 30-39 years and decreased significantly thereafter (p < 0.0001). Visceral fat area and WHR increased significantly with age in both sexes (p < 0.0001). Age was significantly positively correlated with BMI, BF%, fat mass, WHR, and visceral fat area in both sexes (p < 0.0001), and age was negatively correlated with muscle mass in males (standard β =  - 0.14, p < 0.0001) while positive in female (standard β = 0.05, p < 0.0001). Under the BMI criterion, the obesity rate peaked at 27.33% in males at the age of 20-29 years. Under the BF% criterion, the obesity rate peaked at 17.41% in males at the age of 30-39 years, and increased in females with age. The central obesity rate of both sexes increased with age under the criteria of WHR and visceral fat area.

CONCLUSION

The results of this study reveal that age- and sex-related patterns of body composition and obesity change among Beijing adults aged 20-60 years may differ across age groups and that such patterns of change should be considered when developing public health strategies.

The High Prevalence of Sarcopenia in Rheumatoid Arthritis in the Korean Population: A Nationwide Cross-Sectional Study

Rheumatoid arthritis (RA) includes musculoskeletal symptoms that lead to disuse atrophy of muscles and changes in body composition. Musculoskeletal symptoms and loss of physical function may be associated with sarcopenia, which is characterized by muscle loss. This study aimed to investigate the prevalence of sarcopenia and its association with RA in a Korean population. We analyzed nationwide data from the Korea National Health and Nutrition Examination Survey of 7389 men and 9798 women. Binomial logistic regression models were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for sarcopenia prevalence in participants with RA. The prevalence of sarcopenia was 23.0% in men, 25.0% in women, 61.5% in men with RA, 32.3% in women with RA, 22.8% in men without RA, and 24.9% in women without RA. After adjusting for potential confounding variables, the prevalence of sarcopenia was higher in men with RA than in men without RA (OR, 3.11; 95% CI, 1.29-7.46), but this difference was not observed in women. In subgroup analysis which was stratified by age (age under 40, age between 40 and 59, age over 60), the OR for sarcopenia was higher in men with age over 60 years (OR, 4.12; 95% CI, 1.48-11.44) and women with age between 40 and 59 (OR, 2.29; 95% CI, 1.05-5.00). The prevalence of sarcopenia was higher in Korean men with RA and women with RA in middle age, suggesting the management of muscle loss will be needed, especially in Koreans with RA.

Different correlation of body mass index with body fatness and obesity-related biomarker according to age, sex and race-ethnicity

The relationship between body mass index (BMI) and body fatness could differ according to age, sex, and race-ethnicity. We aimed to evaluate in which contexts BMI could be a good measure for body fatness compared to dual-energy X-ray absorptiometry (DXA) derived measures. The study population included 18,061 participants (9141 men and 8920 women) aged 18 and older who tested DXA from the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2006, and 8107 men and 10,754 women with DXA data from Korea NHANES from 2008 to 2011 to represent the Asian population. We calculated Pearson correlation coefficients between BMI and DXA derived fat mass index (FMI) and percentage body fat (PBF) depending on age, sex, and race-ethnicity. The correlation between BMI, FMI and PBF and obesity-related biomarkers was also estimated among the subgroup with both DXA and information on each biomarker. BMI was strongly correlated with FMI (r = 0.944 in men and 0.976 in women), PBF (r = 0.735 in men and 0.799 in women), and truncal fat mass (r = 0.914 in men and 0.941 in women) with correlations stronger in women than in men except for with waist-height ratio (r = 0.921 in men and 0.911 in women). The correlation between BMI and DXA derived adiposity weakened with age in both sexes. BMI was less correlated with FMI (r = 0.840 in men and 0.912 in women), PBF (r = 0.645 in men and 0.681 in women), and truncal fat mass (r = 0.836 in men and 0.884 in women) in Korean compared to other race-ethnicities. Among obesity-related biomarkers, insulin was the most strongly correlated to body adiposity indices in both sexes and strength of these correlations generally decreased with age. BMI predicted obesity-related biomarkers as well as FMI and truncal fat mass and superior to PBF. BMI could be a good measure for body fatness, particularly among young age groups, women, the US population, but less so in Korean populations. The lower correlation between BMI and body fatness in older compared to younger age groups could be related to increasing PBF and decreasing lean body mass.

Association of Change in Smoking Status and Subsequent Weight Change with Risk of Nonalcoholic Fatty Liver Disease

Background/Aims

Smoking is considered a risk factor for the development of nonalcoholic fatty liver disease (NAFLD). However, the association of a weight change after a change in smoking status and the risk of NAFLD remains undetermined.

Methods

This study used the Korean National Health Insurance Service-National Sample Cohort. Based on the first (2009 to 2010) and second (2011 to 2012) health examination periods, 139,180 adults aged at least 40 years were divided into nonsmoking, smoking cessation, smoking relapse, and sustained smoking groups. NAFLD was operationally defined using the fatty liver index. The adjusted odds ratio (aOR) and 95% confidence interval (CI) were calculated using multivariable-adjusted logistic regression.

Results

Compared to nonsmoking with no body mass index (BMI) change, the risk of NAFLD was significantly increased among subjects with BMI gain and nonsmoking (aOR, 4.07; 95% CI, 3.77 to 4.39), smoking cessation (aOR, 5.52; 95% CI, 4.12 to 7.40), smoking relapse (aOR, 7.51; 95% CI, 4.81 to 11.72), and sustained smoking (aOR, 6.65; 95% CI, 5.33 to 8.29), whereas the risk of NAFLD was reduced among participants with BMI loss in all smoking status groups. In addition, smoking cessation (aOR, 1.76; 95% CI, 1.35 to 2.29) and sustained smoking (aOR, 1.64; 95% CI, 1.39 to 1.94) were associated with higher risk of NAFLD among participants with no BMI change. The liver enzyme levels were higher among participants with smoking cessation and BMI gain.

Conclusions

Monitoring and management of weight change after a change in smoking status may be a promising approach to reducing NAFLD.

Assessment of Standing Multi-Frequency Bioimpedance Analyzer to Measure Body Composition of the Whole Body and Limbs in Elite Male Wrestlers

We investigated differences in body composition measurements for the whole body and limb segments in elite male wrestlers between results of multi-frequency bioelectrical impedance analyses (MF_BIA) and dual energy X-ray absorptiometry (DXA). Sixty-six elite male wrestlers from Taiwan were recruited. Wrestlers' body fat percentage (PBF_WB), whole body fat-free mass (FFM_WB), whole body lean soft tissue mass (LSTM_WB), and fat-free mass of arms, legs and trunk (FM_Arms, FFM_Legs, FFM_Trunk) were measured by MF_BIA and DXA, and analyzed using Pearson correlation coefficient and Bland-Altman plot. Correlations of FFM_WB, LSTM_WB, and PBF_WB between devices were 0.958, 0.954, and 0.962, respectively. Limits of agreement (LOA) of Bland-Altman plot were -4.523 to 4.683 kg, -4.332 to 4.635 kg and -3.960 to 3.802%, respectively. Correlations of body composition parameters FFM_Arms, FFM_Legs and FFM_Turnk between devices in each limb segment were 0.237, 0.809, and 0.929, respectively; LOAs were -2.877 to 2.504 kg, -7.173 to -0.015 kg and -5.710 to 0.777 kg, respectively. Correlation and consistency between the devices are high for FFM, LSTM and PBF but relatively low for limb segment FFM. MF_BIA may be an alternative device to DXA for measuring male wrestlers' total body composition but limb segment results should be used cautiously.

Body composition reference values in Singaporean adults using dual-energy X-ray absorptiometry-The Yishun study

OBJECTIVES

This study establishes age- and sex-specific reference values for fat mass index (FMI), lean mass index (LMI), appendicular LMI (aLMI), and body fat distribution indices including Android/Gynoid % fat ratio and Trunk/Limb % fat ratio in multi-ethnic Singaporean adults.

METHODS

A population-based cross-sectional study using dual-energy X-ray absorptiometry (Hologic Discovery Wi) was carried out to measure whole body and regional fat and lean mass in community-dwelling adults. A total of 537 adults (57.5% women), aged from 21 to 90 years, were recruited from the large north-eastern residential town of Yishun. Age- and sex-specific percentile reference values were generated for FMI, LMI, aLMI, Android/Gynoid % fat ratio and Trunk/Limb % fat ratio using the Lambda-Mu-Sigma method. The relationship between the parameters and age were assessed through the Pearson's correlation coefficient.

RESULTS

All parameters demonstrated significant correlation with age (p < 0.05) for both men and women, except for LMI in women, with the strength of r ranging from 0.12 (weak correlation) to 0.54 (strong correlation). LMI (r = -0.45) and appendicular LMI (r = -0.54) were negatively associated with age in men while none (r = -0.06) to weak correlation (r = -0.14) were shown in women for the same parameters respectively. The Android/Gynoid % fat ratio and Trunk/Limb % fat ratio were positively related to age for both men (r = 0.37 & 0.43, p < 0.001) and women (r = 0.52 & 0.48, p < 0.001).

CONCLUSION

We have established DXA-based body composition reference data for the Singapore adult population. These reference data will be particularly useful in geriatric, obesity and oncology clinics, enabling the prescription of appropriate therapy to individuals at risk of morbidity from unfavorable body composition phenotypes. It also adds on to the limited reference database on Southeast Asian body composition.

Development of an Obesity Information Diagnosis Model Reflecting Body Type Information Using 3D Body Information Values

This study uses various body values (length, circumference, and volume) that can be derived from 3D data to determine variables and areas that substantially affect obesity and suggests guidelines for diagnosing obesity that are more elaborate than existing obesity indices. Body data for 170 participants (87 men and 73 women aged 20-30 years) are collected for the chest, abdomen, hips, and arms/legs. A 3D scanner, which can produce accurate body point results, and dual-energy X-ray (DEXA), which can accurately determine the fat percentage, are used to derive fat rates for each body part. The fat percentage and total fat percentage for each body part are used as learning data. For the derived data, the eigenvalue for each body part is derived using a principal component analysis, and the following four clusters are created for each part: underweight, normal, overweight, and obese. A comparison with the obesity index, which diagnoses obesity based on the cluster model, showed that the accuracy of the model proposed in this study is higher at 80%. Therefore, this model can determine the body information necessary for accurate obesity diagnosis and be used to diagnose obesity with greater accuracy than obesity indices without a body fat measurement machine such as DEXA.

Association of Shift Work with Normal-Weight Obesity in Community-Dwelling Adults

BACKGRUOUND

Shift work is associated with obesity and metabolic syndrome. However, this association in the normal-weight population remains unclear. This study aimed to investigate whether shift work is associated with normal-weight obesity (NWO).

METHODS

From the nationally representative Korea National Health and Nutrition Examination Survey (KNHANES) dataset (2008 to 2011), 3,800 full-time workers aged ≥19 years with a body mass index (BMI) ≤25 kg/m2 were analysed. We defined NWO as BMI ≤25 kg/m2 and body fat percentage ≥25% in men and ≥37% in women. Working patterns were classified into "daytime," "other than daytime," and "shift." Multivariable logistic regression analysis was performed to evaluate the relationship between shift work and NWO.

RESULTS

Shift work was associated with higher odds of NWO than daytime work (adjusted odds ratio [aOR], 1.47; 95% confidence interval [CI], 1.04 to 2.09) and night/evening work (aOR, 1.87; 95% CI, 1.11 to 3.14) after adjustment for type of work, working hours, age, sex, BMI, 25-hydroxyvitamin D levels, homeostatic model assessment for insulin resistance, and other sociodemographic factors. In subgroup analyses, the association between shift work and NWO was more robust in those aged ≥60 years and those working ≥56 hours/week.

CONCLUSION

Shift work was associated with NWO in community-dwelling Korean adults, independent of age, sex, BMI, and other covariates.

Classification of nutritional status by fat mass index: does the measurement tool matter?

Abstract Assessment of the Nutritional Status (NS) allows screening for malnutrition and obesity, conditions associated with chronic non-communicable diseases. The fat mass index (FMI) stands out concerning traditional NS indicators. However, proposals that define thresholds for FMI are not sensitive to discriminate extreme cases (degrees of obesity or thinness). Only one proposal (NHANES), determined by total body densitometry (DXA), established eight categories of NS classification (FMI). However, DXA is expensive and not always clinically available. Our study aims to test the validity of the NHANES method using electrical bioimpedance (BIA) and skinfold thickness (ST) to classify NS. The FMI of 135 (69 women) university students aged 18 to 30 years old was determined using DXA, BIA, and ST. The agreement between the instruments (Bland-Altman) and the agreement coefficient in the NS classifications (Chi-square and Kappa index) were tested. The agreement test against DXA indicated that ST underestimated the FMI (-1.9 kg/m2) for both sexes and BIA in women (-2.0 kg/m2). However, BIA overestimated FMI (1.4 kg/m2) in men, although with less bias. There was no agreement between the NS classifications (NHANES) by FMI between DXA and BIA, or DXA and ST. The exception occurred between DXA and BIA in men who showed a slightly better consensus, considered “fair” (k = 0.214; p = 0.001). In conclusion, ST and BIA did not show enough agreement to replace DXA for NS classification, within NHANES thresholds. The FMI measurement tools for the NHANES classification of the categories of NS matters.

Muscle Exercise Mitigates the Negative Influence of Low Socioeconomic Status on the Lack of Muscle Strength: A Cross-Sectional Study

Socioeconomic status (SES), which takes into account household income and education level, is an important factor in the role of muscle strength as a discriminator of sarcopenia. Although the benefits of exercise on muscle strength are well recognized, its influence on people of different SES has not been fully elucidated, informing the aim of this study. A total of 6081 subjects, for which we had complete data on measurements of handgrip strength (HGS) and other relevant variables, were included from the Korea National Health and Nutrition Examination Surveys (KNHANES) VII-3. A multivariable analysis showed that people with a low household income (odds ratio (OR) 1.637, p = 0.005) and low education status (OR 2.351, p < 0.001) had a poor HGS compared to those with a high SES, and that the difference in HGS made by muscle exercise was greater for people with a low household income (OR 7.082 vs. 3.619, p < 0.001) and low education status (OR 14.711 vs. 6.383, p < 0.001). Three-step logistic regression analysis showed that muscle exercise mediated the relationship between muscle strength and low household income (OR from 1.772 to 1.736, z = 2.373, p = 0.017) and low education level (OR from 2.368 to 2.309, z = 2.489, p = 0.012). This study confirmed that exercise improves the negative effect of SES on muscle strength, suggesting the greater importance of muscle exercise for people with a low SES.

Non-alcoholic fatty liver disease and sarcopenia additively increase mortality: a Korean nationwide survey

BACKGROUND

Sarcopenia is an independent risk factor not only for advanced-stage non-alcoholic fatty liver disease (NAFLD) but also for mortality. We investigated the association of sarcopenia and/or NAFLD with mortality among the Korean general population.

METHODS

Individuals aged 35-75 years without any history of cancer, ischaemic heart disease, ischaemic stroke, or secondary causes of chronic liver disease were selected from the Korean National Health and Nutrition Examination Surveys from 2008 to 2015. Their mortality data until December 2018 were retrieved from the National Death Registry. NAFLD and sarcopenia were defined by hepatic steatosis index and appendicular skeletal muscle mass divided by body mass index (BMI), respectively.

RESULTS

A total of 28 060 subjects were analysed [mean age, 50.6 (standard error, 0.1) years, 48.2 (0.3) % men]; the median follow-up duration was of 6.8 (interquartile range, 4.8, 8.4) years. NAFLD predicted mortality after adjustment for age, sex, BMI, hypertension, dyslipidaemia, and smoking (HR 1.32, 95% CI 1.03-1.70), but this prediction lost its statistical significance after additional adjustment for diabetes mellitus. In contrast, NAFLD with advanced fibrosis independently increased the risk of mortality after adjustment for all covariates (HR 1.68, 95% CI 1.02-2.79). Stratified analysis revealed that NAFLD and sarcopenia additively increased the risk of mortality as an ordinal scale (HR 1.46, 95% CI 1.18-1.81, P for trend = 0.001). The coexistence of NAFLD and sarcopenia increased the risk of mortality by almost twice as much, even after adjustment for advanced fibrosis (HR 2.18, 95% CI 1.38-3.44).

CONCLUSIONS

Concurrent NAFLD and sarcopenia conferred a two-fold higher risk of mortality. The observation that NAFLD and sarcopenia additively increase mortality suggests that risk stratification would be helpful in predicting mortality among those with metabolic derangement.

Korea National Health and Nutrition Examination Survey, 20th anniversary: accomplishments and future directions

The Korea National Health and Nutrition Examination Survey (KNHANES) was initiated in 1998 to provide evidence for the development and evaluation of health policies and programs. The Korea Disease Control and Prevention Agency is responsible for the KNHANES and has conducted it as a series of surveys. Over the past 20 years, efforts to produce accurate, timely, and nationwide health statistics have been refined by establishing a continuous annual survey system with full-time field staff, incrementally expanding survey components, collaborating with relevant academic societies for quality control, and revising the survey methods. Additionally, the utility of the collected data was increased by linking the KNHANES data with related data from other government agencies or institutions and making the overall data publicly available on the official website of KNHANES (https://knhanes.kdca.go.kr). Additional long-term plans are being developed, including plans to continue producing nationwide health indicators and invigorating the utilization of the KNHANES data.

Age- and Sex-Related Differential Associations between Body Composition and Diabetes Mellitus

BACKGROUND

The age- and sex-related differences on the impacts of body composition on diabetes mellitus (DM) remain uncertain.

METHODS

The fourth and fifth Korea National Health and Nutrition Examination Survey included 15,586 subjects over 30 years of age who completed dual-energy X-ray absorptiometry. We conducted a cross-sectional study to investigate whether muscle mass index (MMI), defined as appendicular skeletal muscle divided by body mass index (BMI), and fat mass index (FMI), defined as trunk fat mass divided by BMI, were differently associated with DM according to age and sex.

RESULTS

In multivariate logistic regression, the risk for DM significantly increased across quartiles of FMI in men aged ≥70. Meanwhile, MMI showed a protective association with DM in men of the same age. The odds ratios (ORs) for the highest quartile versus the lowest quartile of FMI and MMI were 3.116 (95% confidence interval [CI], 1.405 to 6.914) and 0.295 (95% CI, 0.157 to 0.554), respectively. In women, the ORs of DM was significantly different across FMI quartiles in those over age 50. The highest quartile of FMI exhibited increased ORs of DM in subjects aged 50 to 69 (OR, 1.891; 95% CI, 1.229 to 2.908) and ≥70 (OR, 2.275; 95% CI, 1.103 to 4.69) compared to lowest quartile. However, MMI was not significantly associated with DM in women of all age groups.

CONCLUSION

Both FMI and MMI were independent risk factors for DM in men aged 70 years or more. In women over 50 years, FMI was independently associated with DM. There was no significant association between MMI and DM in women.

Complex interaction of fasting glucose, body mass index, age and sex on all-cause mortality: a cohort study in 15 million Korean adults

AIMS/HYPOTHESIS

The aim of this work was to examine whether synergistic associations with mortality exist for BMI and fasting blood glucose (FBG) and to identify FBG-BMI combined subgroups with higher mortality according to sex and age.

METHODS

A total of 15,149,275 Korean adults participated in health examinations during 2003-2006 and were followed up until December 2018. Mortality HRs of 40 FBG-BMI combined groups were assessed by Cox proportional hazards models.

RESULTS

During a mean 13.7 years of follow-up, 1,213,401 individuals died. A J-shaped association was seen between FBG and all-cause mortality for all BMI categories. Those with BMI <20 kg/m² had the highest mortality for any given FBG level, followed by those with BMI 20-22.4 kg/m². The detrimental effect of elevated FBG was greater among leaner individuals than more corpulent individuals. Moreover, the synergistic adverse effects of hyperglycaemia and leanness was stronger in younger adults than in older adults. Compared with the reference group (overweight with normoglycaemia), age- and sex-adjusted HRs of the leanest with normoglycaemia (BMI <20 kg/m² and FBG 4.4-5.2 mmol/l), overweight with diabetes (BMI 25-27.4 kg/m² and FBG ≥10.0 mmol/l) and leanest with diabetes (BMI <20 kg/m² and FBG ≥10.0 mmol/l) were 1.29, 2.59 and 11.18, respectively, in those aged 18-44 years and 1.56, 1.72 and 2.87, respectively, in those aged 75-99 years. The identification of BMI-FBG subgroups associated with higher mortality was not straightforward, illustrated by the group with FBG 6.1-6.9 mmol/l and BMI 20-22.4 kg/m² having a similar or higher mortality compared with the group with FBG 7.0-9.9 mmol/l and BMI ≥22.5 kg/m². In women aged <45 years with FBG <6.9 mmol/l, those with BMI ≥27.5 kg/m² had the highest mortality, whereas individuals with BMI <20 kg/m² had the highest mortality for each given FBG level in other age and sex groups.

CONCLUSIONS/INTERPRETATION

Leanness and hyperglycaemia interact together to increase mortality in a supra-multiplicative manner, especially in younger adults; the interactions of BMI, FBG, sex and age with mortality are complex. Graphical abstract.

Reference values of body composition parameters and visceral adipose tissue (VAT) by DXA in adults aged 18-81 years-results from the LEAD cohort

Background

Increasing attention has been drawn on the assessment of body composition phenotypes, since the distribution of soft tissue influences cardio-metabolic risk. Dual-energy X-ray absorptiometry (DXA) is a validated technique to assess body composition. European reference values from population-based cohorts are rare.

Aims

To provide age- and sex-related reference values of body composition parameters and visceral adipose tissue (VAT) mass, and for lean mass index (LMI) with regard to fat mass index (FMI) quantities and BMI categories.

Methods

GE-Lunar Prodigy DXA scans of 10.894 participants, aged 18–81 years, recruited from 2011 to 2019 by the Austrian LEAD study, a population-based cohort study, have been used to construct reference curves using the LMS method. Parameters assessed are FMI, LMI, appendicular LMI, fat mass ratios android/gynoid and trunk/limbs, and VAT.

Results

All lean mass and fat mass parameters indicating central fat accumulation were higher in men, whereas other fat mass indices were higher in women. LMI differed between each FMI subgroup (low vs. normal, low vs. high, normal vs. high), and BMI category in all ages and LMI increased with FMI and BMI classes. VAT mass was higher in men compared with women and increased across all age groups within both sexes.

Conclusion

The present study provides age- and sex-related reference values for European adults aged 18–81 years for body composition parameters and VAT mass for Lunar Prodigy DXA. In addition, this study reports LMI reference values with regard to fat mass quantities, showing a positive association with increasing FMI percentiles and BMI categories.

Clinical Manifestations and Factors Associated with Osteosarcopenic Obesity Syndrome: A Cross-Sectional Study in Koreans with Obesity

Demonstrating the clinical consequences of osteosarcopenic obesity (OSO) is complex. This study evaluated clinical manifestations and factors associated with bone and muscle loss in Koreans with obesity. This cross-sectional observational study enrolled Koreans with obesity aged ≥ 50 years from the Korea National Health and Nutrition Examination Survey. Clinical manifestations were compared among four groups: obesity (O), sarcopenic obesity (SO), osteopenic obesity (OO), and OSO. Factors associated with appendicular skeletal muscle mass (ASM) or bone mineral density (BMD) were evaluated. OSO increases with age in both sexes. Men with SO and OSO had increased cardiometabolic diseases and markers, percentages of body fat (BF %), and trunk fat (TF %), and decreased limb fat percentage (LF %). Women with SO and OSO had increased metabolic markers, BF %, and TF % but those with OSO had increased cardiometabolic diseases and lower LF %. Both sexes with OSO had decreased ASM and vitamin D, and higher vitamin D deficiency. BF % was negatively associated with ASM and femur BMD in both sexes. TF % was negatively and LF % was positively associated with ASM in both sexes and with femur BMD in women. Vitamin D was positively associated with femur BMD in men and with ASM and BMD at all sites in women. ASM and BMD were positively associated with each other. Appendicular muscle loss is metabolically significant regardless of bone loss in men; however, appendicular muscle loss with bone loss is metabolically more significant in women. Regional body composition, fat distribution, and vitamin D deficiency were associated with OSO phenotype in both sexes.

Body composition indices in Brazilian adults: age-specific and sex-specific percentile curves

OBJECTIVE

To establish percentile curves for measures and indices of body composition by age and sex and compare them with data from other ethnic groups.

SUBJECTS AND METHODS

Cross-sectional, population-based study with adults aged 20-59 years (n = 689). Percentile curves adjusted by a third degree polynomial function were constructed for skeletal mass index (SMI), fat mass index, body fat, and load-capacity metabolic indices (LCMI) based on dual-energy X-ray absorptiometry (DXA).

RESULTS

SMIweight and SMIBMI showed decline from the third decade of life in both sexes, whereas SMIheight was not able to identify lean mass loss over the ages studied. There was a slight drop at the end of the fifth decade (50-59 years) in men. Among Americans and Chinese, the 50th percentile curve of SMIheight showed an earlier decline. The estimates of adiposity and LCMI curves peaked between 40-49 years and Americans and Chinese maintained an upward curve throughout adulthood.

CONCLUSION

The data and curves showed that the SMI adjusted for BMI and body weight were more adequate in detecting the decline of lean mass in adults due to aging. In contrast, SMIheight had a positive correlation with age and its curve increased throughout the evaluated age groups. The results contribute to the evaluation to the nutritional status of adults and to the prevention and treatment of outcomes related to adiposity and deficit lean mass.

Comparisons of different indices of low muscle mass in relationship with cardiometabolic disorder

This study aimed to evaluate the most valid index among various indices of low muscle mass in assessing cardiometabolic risks in a Korean population. Appendicular lean mass index (ALMI, kg/m2), fat mass index (FMI, kg/m2), FMI-adjusted ALMI (ALMfmi), ratio of ALM to weight index (ALMwt), ratio of ALM to body mass index (ALMbmi) and ratio of ALM to truncal fat index (ALMtrunkfat) were measured by dual energy X-ray absorptiometry in 17,870 participants from 2008 to 2011. We adopted all the aforementioned indices of low muscle mass expressed as sex- and age-specific standard deviation scores (Z-scores). Low muscle mass for age was defined as Z-score <-1. The prevalence of low muscle mass was approximately 16% across all indices. Low muscle mass defined by ALMI had low muscle mass and low fat mass, and ALMfmi had low muscle mass at the same FMI. However, low muscle mass defined by ALMwt, ALMbmi and ALMtrunkfat had similar muscle mass with high FMI. The receiver operating characteristic curve in metabolic syndrome showed that the ALMtrunkfat was 0.74 in male and 0.69 in female, indicating that ALMtrunkfat was the best discrimination index for metabolic syndrome. This study showed that ALMtrunkfat could be a useful indicator for screening cardiometabolic risk factors, particularly in normal or overweight Asian population.

The Differential Effect of Excess Aldosterone on Skeletal Muscle Mass by Sex

The effects of excess aldosterone on skeletal muscle in individuals with primary aldosteronism (PA) are unknown. To examine the effects of aldosterone on skeletal muscle mass in patients with PA, by sex, 309 consecutive patients were enrolled. Skeletal muscle and fat mass of 62 patients with PA were compared with those of 247 controls with non-functioning adrenal incidentaloma (NFAI). Body composition parameters were measured using bioelectrical impedance analysis, and plasma aldosterone concentration (PAC) was measured using radioimmunoassay. The PAC in all women, but not in men, showed an inverse association with both appendicular skeletal muscle mass (ASM) (β = -0.197, P = 0.016) and height-adjusted ASM (HA-ASM) (β = -0.207, P = 0.009). HA-ASM in women (but not in men) with PA was 5.0% lower than that in women with NFAI (P = 0.036). Furthermore, women with PA had a lower HA-ASM than 1:1 age- and sex-matched controls with NFAI by 5.7% (P = 0.049) and tended to have a lower HA-ASM than 1:3 age-, sex-, and menopausal status-matched controls without adrenal incidentaloma (AI) by 7.3% (P = 0.053). The odds ratio (OR), per quartile increase in PAC, of low HA-ASM in women was 1.18 [95% confidence interval (CI), 1.01-1.39; P = 0.035]. The odds of HA-ASM in subjects with PA were 10.63-fold (95% CI: 0.83-135.50) higher, with marginal significance (P = 0.069) than in those with NFAI. Skeletal muscle mass in women with PA was lower than that in women with NFAI; suggesting that excess aldosterone has adverse effects on skeletal muscle metabolism.

Characteristics and reference values of fat mass index and fat free mass index by bioelectrical impedance analysis in an adult population

BACKGROUND & AIMS

We aim to examine the influence of sex, age, region and ethnicity on fat mass index (FMI) and fat free mass index (FFMI), and to establish FMI and FFMI reference values in Chinese adults.

METHODS

A stratified cluster sampling method was adopted to enroll Chinese participants in this cross-sectional study. Questionnaire surveys and medical examinations were performed to collect data, and body composition parameters were measured by bioelectrical impedance analysis. FMI and FFMI were calculated as the ratio of fat mass and fat free mass to the square of height. Differences in mean values for parameters were tested by Student's t-test or one-way analysis of variance. Reference values of FMI and FFMI were obtained using the percentiles method.

RESULTS

A total of 8959 multiethnic healthy Chinese adults were included in the analysis. Males had higher mean FFMI (males, 18.6 ± 1.6 kg/m²; females, 15.7 ± 1.1 kg/m², P < 0.001) but lower mean FMI (males, 5.1 ± 2.1 kg/m²; females, 7.8 ± 2.8 kg/m², P < 0.001) than did female participants regardless of age and ethnicity. For both sexes, FMI (Male: Bouyei, 4.2 ± 1.8 kg/m²; Uygur, 5.8 ± 2.2 kg/m², P < 0.001; Female: Bouyei, 6.7 ± 2.3 kg/m²; Uygur, 9.0 ± 3.2 kg/m², P < 0.001) and FFMI (Male: Bouyei, 17.8 ± 1.4 kg/m²; Uygur, 19.4 ± 1.6 kg/m², P < 0.001; Female: Bouyei, 15.1 ± 1.0 kg/m²; Uygur, 16.3 ± 1.1 kg/m², P < 0.001) were lowest in Bouyeis and highest in Uygurs. FMI and FFMI values increased with age until they peaked in the 30-39 year age group in males and after the age of 40 years in females for all ethnic groups. Reference values (5th-95th percentile) of FMI and FFMI were presented according to gender, age, region and ethnicity.

CONCLUSION

The body composition of Chinese population differs in different age, sex, ethnicity and region subgroups. Practitioners and future studies may need to consider different reference values for FMI and FFMI in Chinese adults among Han, Bouyei and Uygur populations; these values can serve as indices for evaluating nutrition status and identifying abnormalities in body composition.

Weight gain after smoking cessation does not modify its protective effect on myocardial infarction and stroke: evidence from a cohort study of men

Aims

This study aimed to investigate the association between smoking cessation, post-cessation body mass index (BMI) change and risk of myocardial infarction (MI) and stroke in men.

Methods and results

A prospective cohort study using the National Health Insurance Service (NHIS) data set collected from 2002 to 2013 was implemented. Based on the first (2002-03) and second (2004-05) NHIS health check-up periods, 108 242 men aged over 40 years without previous diagnoses of MI or stroke were grouped into sustained smokers, quitters with BMI gain, quitters without BMI change, quitters with BMI loss, and non-smokers. Body mass index change was defined as the difference of more than 1.0 kg/m2 between the two health check-up periods. The participants were followed-up from 1 January 2006 to 31 December 2013. Hazard ratios (HRs) and 95% confidence intervals (HR, 95% CI) were computed using Cox proportional hazard models adjusted for sociodemographic, health status, and family health history. Compared to the sustained smokers, the risk of MI and stroke was significantly reduced in both quitters with BMI gain (HR 0.33; 95% CI 0.16-0.70 for MI and HR 0.75; 95% CI 0.57-1.00 for stroke) and without BMI change (HR 0.55; 95% CI 0.37-0.83 for MI and HR 0.75; 95% CI 0.62-0.92 for stroke), but no significant association was found in quitters with BMI loss (HR 0.91; 95% CI 0.43-1.91 for MI and HR 0.86; 95% CI 0.57-1.31 for stroke), respectively. Non-smokers had lower risk of MI (HR 0.37; 95% CI 0.32-0.43) and stroke (HR 0.68; 95% CI 0.64-0.73) compared to the sustained smokers.

Conclusion

Post-cessation BMI change did not significantly modify the protective association of smoking cessation with MI and stroke.

Discrepancies between subjective perception and waist-to-height ratio measurement of obesity, and their policy implications

In social sciences, researchers rely on subjective perceptions of obesity measures to examine the determinants of obesity and the likely effects of obesity on health outcomes. However, subjective perception tends to produce estimation biases. In this study, we investigated the misreporting behavior of individuals regarding obesity using waist-to-height ratio as an objective measurement of obesity. Using the Korean National Health and Nutrition Examination Survey for 2008-2011, we showed that false-reporting behavior was significantly associated with socio-economic status. Furthermore, we presented that subjective perception of obesity yielded misleading estimates in both the determinants and the consequences of obesity.

Body composition by DXA

Body composition measurements from DXA have been available since DXA technology was developed 30years ago, but are historically underutilized. Recently, there have been rapid developments in body composition assessment including the analysis and publication of representative data for the US, official usage guidance from the International Society for Clinical Densitometry, and development of regional body composition measures with clinical utility. DXA body composition is much more than whole body percent fat. In this paper celebrating 30years of DXA for body composition, we will review the principles of DXA soft tissue analysis, practical clinical and research applications, and what to look for in the future.

Body composition analysis by DXA (dual X-ray absorptiometry) in Brazilian men: normative data

Considering ethnic and anthropometric differences, it is important to obtain specific normative data on body composition (BC) for each population. The objectives of this study were to obtain the normative curve for the BC of Brazilian men and to compare them to the North American male population. A total of 403 healthy Brazilian men 20 years and older were included in the study. Data on concomitant diseases and physical activity were investigated using a structured questionnaire. Conditions that could affect lean and fat mass were excluded. BC was assessed via whole-body dual-energy X-ray absorptiometry (DXA) using a GE-Lunar device. Significance level was set as p < 0.05. Mean age and body mass index (BMI) were 46.0 ± 17.9 years and 26.2 ± 3.14 kg/m², respectively. Mean skeletal mass index (SMI), appendicular lean mass by BMI (ALM_BMI), and fat mass index (FMI) were 8.38 ± 0.85, 0.949 ± 0.138, and 6.87 ± 2.43 kg/m², respectively. There were negative associations among SMI (p < 0.001), ALM_BMI (p < 0.001), and FMI (p = 0.002) with age. Comparison with the National Health and Nutrition Examination Survey (NHANES) III data, originally performed with a Hologic device, showed that Brazilian men had lower FMI and BF. This difference was minimized after converting the NHANES results to the GE-Lunar database. Brazilian men had lower SMI than American men measured in NHANES III. FMI was less influenced by ethnicity than by BMI, and it could be used as a standard measure for assessing fat excess or adiposity. Our data suggest that conversion to each specific manufacturer's database should be performed to minimize differences in body composition between populations.

Reference standards for lean mass measures using GE dual energy x-ray absorptiometry in Caucasian adults

OBJECTIVE

To develop reference values by age and sex for LM measures using GE-Healthcare DXA systems.

METHODS

A de-identified sample was obtained from Ball State University's Clinical Exercise Physiology Laboratory and University of Wisconsin-Milwaukee's Physical Activity & Health Research Laboratory. DXA scans of 2,076 women and 1,251 men were completed using a GE Lunar Prodigy or iDXA. Percentiles (%ile) were calculated for all variables of interest (LM, LMI, %LM, and ALMI) and a factorial ANOVA was used to assess differences for each variable between 10-year age groups and sex, as well as the interaction between age and sex.

RESULTS

Men had higher mean total LM, %LM, LMI, and ALMI than women (p<0.01), across all age groups. All LM variables decreased significantly over the 5 decades in men, however in women only total LM, %LM, and ALMI decreased from the youngest to oldest age groups (p<0.01).

CONCLUSION

These reference values provide for a more accurate interpretation of GE-Healthcare DXA-derived LM measurements offering clinicians and researchers with an initial resource to aid in the early detection and assessment of LM deficits.

Reference standards for body fat measures using GE dual energy x-ray absorptiometry in Caucasian adults

Background

Dual energy x-ray absorptiometry (DXA) is an established technique for the measurement of body composition. Reference values for these variables, particularly those related to fat mass, are necessary for interpretation and accurate classification of those at risk for obesity-related health complications and in need of lifestyle modifications (diet, physical activity, etc.). Currently, there are no reference values available for GE-Healthcare DXA systems and it is known that whole-body and regional fat mass measures differ by DXA manufacturer.

Objective

To develop reference values by age and sex for DXA-derived fat mass measurements with GE-Healthcare systems.

Methods

A de-identified sample of 3,327 participants (2,076 women, 1,251 men) was obtained from Ball State University’s Clinical Exercise Physiology Laboratory and University of Wisconsin-Milwaukee’s Physical Activity & Health Research Laboratory. All scans were completed using a GE Lunar Prodigy or iDXA and data reported included percent body fat (%BF), fat mass index (FMI), and ratios of android-to-gynoid (A/G), trunk/limb, and trunk/leg fat measurements. Percentiles were calculated and a factorial ANOVA was used to determine differences in the mean values for each variable between age and sex.

Results

Normative reference values for fat mass variables from DXA measurements obtained from GE-Healthcare DXA systems are presented as percentiles for both women and men in 10-year age groups. Women had higher (p<0.01) mean %BF and FMI than men, whereas men had higher (p<0.01) mean ratios of A/G, trunk/limb, and trunk/leg fat measurements than women.

Conclusion

These reference values provide clinicians and researchers with a resource for interpretation of DXA-derived fat mass measurements specific to use with GE-Healthcare DXA systems.

Sex- and age-specific percentiles of body composition indices for Chinese adults using dual-energy X-ray absorptiometry

Purpose

The aims of the study were to develop sex- and age-specific percentiles for lean mass index (LMI), appendicular LMI (aLMI), fat mass index (FMI), and body fat distribution indices in Chinese adults using dual-energy X-ray absorptiometry (DXA), and to compare those indices with those of other ethnicities using the US NHANES data.

Methods

Whole-body and regional lean mass and fat mass (FM) were measured using DXA in 5688 healthy males (n = 1693) and females (n = 3995) aged 20–90 years. Body fat distribution indices were expressed as % fat trunk/% fat legs, trunk/appendicular FM ratio (FMR), and android/gynoid FMR. Percentile curves of LMI, aLMI, FMI, and body fat distribution indices were obtained by the Lambda–Mu–Sigma method.

Results

The aLMI and LMI were negatively associated with age, decreasing from the fifth decade for males, but were not associated with age in females. Females had more total FM than males, whereas males had greater central adiposity (% fat trunk/% fat legs ratio, trunk/appendicular FMR, and android/gynoid FMR) than females. Moreover, FMI and body fat distribution indices consistently increased with age in both sexes, especially in women. In comparison with white, black, and Mexican populations in the USA, Chinese adults had lower total FM, but had greater central adiposity (% fat trunk/% fat legs ratio and trunk/appendicular FMR). Additionally, older white and Mexican populations showed greater decreases for aLMI and LMI than their Chinese counterparts.

Conclusions

We present the sex- and age-specific percentiles for aLMI, LMI, FMI, and body fat distribution indices by DXA in Chinese adults, which may refine the individual assessment of the nutritional status of Chinese adults.

The effects of sarcopenia and obesity on femur neck bone mineral density in elderly Korean men and women

Objectives

We aimed to clarify the relationship between fat, muscle, and bone in elderly men and women.

Methods

We analyzed 1373 men and 1803 women who were older than 65 years from the 2008–2010 Korea National Health and Nutritional Examination Surveys. Body composition and femur neck bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry. Sarcopenia was defined as an appendicular skeletal muscle index (SMI) below one standard deviation (SD). Obesity was classified by fat mass index (FMI). Osteoporosis was defined as a BMD of 2.5 SD below that of femur neck BMD.

Results

SMI and FMI were positively correlated with femur neck BMD. In multiple regression analysis, SMI (β = 0.302 in men, β = 0.154 in women; p < 0.001 each) and FMI (β = 0.079 in men, β = 0.179 in women; p = 0.003 and p < 0.001 respectively) had a positive relationship with femur neck BMD. Men with sarcopenia were 3.89 times more likely to develop osteoporosis. Women with sarcopenia were 1.87 times more likely to develop osteoporosis. Sarcopenia was more clinically significant in the development of osteoporosis in men with a fat deficit and women with excess fat.

Conclusions

Muscle mass and fat mass were identified as determinants of femur neck BMD in men and women. Among them, muscle mass of men and fat mass of women are the most important determinants of femur neck osteoporosis.

Gender Difference in Body Fat for Healthy Chinese Children and Adolescents

BACKGROUND

This study aimed to establish gender-related differences and the percentile curves for total body fat mass percentage (Total FM%), trunk/appendicular fat mass ratio (TrAppFMR), and fat mass ratio as % fat trunk/% fat lower limb (TrLLFMR) in Chinese children and adolescents using dual-energy X-ray absorptiometry (DXA).

METHODS

Children (n = 1541; 764 girls) and adolescents aged 5 to 19 years were recruited from southern China. Total FM% and regional FM were measured by DXA. TrAppFMR values were calculated as trunk FM divided by appendicular FM, and TrLLFMR values were calculated as the ratio between the percentage of trunk FM and the percentage of lower limb FM.

RESULTS

Total FM% peaks for boys were at approximately age 11 years and continued to increase for girls throughout adolescence. Median Total FM% at the age of 19 years was 15.53% and 28.06% for boys and girls, respectively. Median TrAppFMR and TrLLFMR increases were 61% and 81% from 5 to 19 years of age in boys compared with those in girls, 31% and 54%. The curves for median TrAppFMR and TrLLFMR in girls were relatively flat, with TrAppFMR and TrLLFMR remaining near 1.0 after 16 years of age, whereas in boys, median TrAppFMR and TrLLFMR increased with age until approximately 19 years.

CONCLUSIONS

Gender differences in the patterns of proportion and distribution of body fat were found. We present sex-specific percentile curves for Total FM%-age, TrAppFMR-age, and TrLLFMR-age relationships in this population.

Development and Validation of Osteoporosis Risk-Assessment Model for Korean Men

PURPOSE

The aim of the present study was to develop an osteoporosis risk-assessment model to identify high-risk individuals among Korean men.

MATERIALS AND METHODS

The study used data from 1340 and 1110 men ≥50 years who participated in the 2009 and 2010 Korean National Health and Nutrition Examination Survey, respectively, for development and validation of an osteoporosis risk-assessment model. Osteoporosis was defined as T score ≤-2.5 at either the femoral neck or lumbar spine. Performance of the candidate models and the Osteoporosis Self-assessment Tool for Asian (OSTA) was compared with sensitivity, specificity, and area under the receiver operating characteristics curve (AUC). A net reclassification improvement was further calculated to compare the developed Korean Osteoporosis Risk-Assessment Model for Men (KORAM-M) with OSTA.

RESULTS

In the development dataset, the prevalence of osteoporosis was 8.1%. KORAM-M, consisting of age and body weight, had a sensitivity of 90.8%, a specificity of 42.4%, and an AUC of 0.666 with a cut-off score of -9. In the validation dataset, similar results were shown: sensitivity 87.9%, specificity 39.7%, and AUC 0.638. Additionally, risk categorization with KORAM-M showed improved reclassification over that of OSTA up to 22.8%.

CONCLUSION

KORAM-M can be simply used as a pre-screening tool to identify candidates for dual energy X-ray absorptiometry tests.

Association between shift work and obesity according to body fat percentage in Korean wage workers: data from the fourth and the fifth Korea National Health and Nutrition Examination Survey (KNHANES 2008-2011)

BACKGROUND

Health problems in shift workers vary including obesity acting as a risk factor in cerebrovascular diseases. Recent studies have commonly determined the prevalence of obesity in shift workers on the basis of body mass index. The accuracy of BMI for diagnosing obesity are still limited apparently. Consequently, this study aimed to determine the relationship between shift work and obesity according to the total body fat percentage in Korean wage workers.

METHODS

From the Fourth and the Fifth Korea National Health and Nutrition Examination Survey (2008-2011), after military personnel were excluded, a total of 2952 wage workers (20 ≤ age ≤ 65) whose current jobs were their longest jobs were selected as subjects of the study. The total body fat percentage was used to determine the obesity standards (≥25.7 % in males and ≥36.0 % in females). The subjects were divided into groups by gender and work type (manual vs non-manual), and chi-squared test was used to evaluate the relationship between socio-economic, health behavior, and work-related factors, on the one hand, and obesity, on the other. In addition, multivariate logistic regression analysis was performed to examine the effects of shift work on obesity.

RESULTS

When other factors were controlled for, the risk of obesity in shift work showed a statistically significant increase (odds ratio = 1.779, 95 % confidence interval = 1.050-3.015) in the male manual worker group. However, there were no significant results in the male non-manual and female worker groups.

CONCLUSION

Shift work was related to a higher risk of obesity in the Korean male manual worker group.

Association Between Obesity, Abdominal Obesity, and Adiposity and the Prevalence of Atopic Dermatitis in Young Korean Adults: the Korea National Health and Nutrition Examination Survey 2008-2010

PURPOSE

Whether obesity is a risk factor for atopic dermatitis (AD) remains unclear. The aim of the present study was to investigate the association between obesity and AD in Korean young adults.

METHODS

We included nationally representative data of 5,202 Korean adults aged 19-40 years, obtained from the cross-sectional Korea National Health and Nutrition Examination Survey 2008-2010.

RESULTS

Single (unmarried) status was more frequently observed in AD patients (male, [P=0.0002] and female, [P<0.0001]). AD prevalence exhibited a U-shape trend in relation to body mass index (BMI), waist circumference (WC), and total body fat (BF) percentage, especially in young adult women. Women with BMI ≥25 kg/m², WC ≥80 cm, and highest quartile (Q4) of total BF percentage had the highest prevalence of AD. The odds ratio (OR) for participants with both BMI ≥25 kg/m² and WC ≥80 cm was 3.29 (95% confidence interval [CI] 1.71-3.55); therefore, having both general and abdominal obesity was considered a prominent risk factor for AD in young women. After adjustment for confounding factors, including age, smoking, alcohol drinking, exercise, vitamin D, income level, and single status, high BMI (≥30 kg/m²) (OR=4.08, 95% CI: 1.53-10.93), high WC (≥80 cm) (OR=2.05, 95% CI: 1.07-3.94), and high BF percentage (Q4) (OR=2.10, 95% CI: 1.24-3.57) were shown to be significantly associated with AD in young adult women.

CONCLUSIONS

In this large-scale nation-wide study of Korean adults, obesity was positively related to the presence of AD in women. Our findings suggest that weight management may help prevent AD.

Parathyroid hormone, calcium, and sodium bridging between osteoporosis and hypertension in postmenopausal Korean women

The coexistence of osteoporosis and hypertension, which are considered distinct diseases, has been widely reported. In addition, daily intake of calcium and sodium, as well as parathyroid hormone levels (PTH), is known to be associated with osteoporosis and hypertension. This study aimed to determine the association of low calcium intake, high sodium intake, and PTH levels with osteoporosis and hypertension in postmenopausal Korean women. Data for postmenopausal Korean women aged 50 years or older were obtained from the Korea National Health and Nutrition Examination Survey 2008-2011. Osteoporosis was diagnosed using dual energy X-ray absorptiometry, while hypertension was diagnosed using blood pressure data. The odds ratios for osteoporosis and hypertension were calculated using logistic regression analysis for quartiles of the daily calcium intake, daily sodium intake, and PTH levels. Women with hypertension had a high coexistence of osteoporosis (43.6 vs. 36.5 %; P = 0.022), and vice versa (21.1 vs. 16.6 %; P = 0.022). PTH was significantly associated with osteoporosis and hypertension, and a high intake of calcium was strongly correlated with a low incidence of osteoporosis. This is the first study to report the characteristics of postmenopausal Korean women who have high dietary sodium intake and low dietary calcium intake, in association with the incidence of osteoporosis and hypertension. Osteoporosis and hypertension were strongly associated with each other, and PTH appears to be a key mediator of both diseases, suggesting a possible pathogenic link.

Multi-component molecular-level body composition reference methods: evolving concepts and future directions

Excess adiposity is the main phenotypic feature that defines human obesity and that plays a pathophysiological role in most chronic diseases. Measuring the amount of fat mass present is thus a central aspect of studying obesity at the individual and population levels. Nevertheless, a consensus is lacking among investigators on a single accepted 'reference' approach for quantifying fat mass in vivo. While the research community generally relies on the multi-component body volume class of 'reference' models for quantifying fat mass, no definable guide discerns among different applied equations for partitioning the four (fat, water, protein and mineral mass) or more quantified components, standardizes 'adjustment' or measurement system approaches for model-required labelled water dilution volumes and bone mineral mass estimates, or firmly establishes the body temperature at which model physical properties are assumed. The resulting differing reference strategies for quantifying body composition in vivo leads to small, but under some circumstances, important differences in the amount of measured body fat. Recent technological advances highlight opportunities to expand model applications to new subject groups and measured components such as total body protein. The current report reviews the historical evolution of multi-component body volume-based methods in the context of prevailing uncertainties and future potential.

Data resource profile: the Korea National Health and Nutrition Examination Survey (KNHANES)

The Korea National Health and Nutrition Examination Survey (KNHANES) is a national surveillance system that has been assessing the health and nutritional status of Koreans since 1998. Based on the National Health Promotion Act, the surveys have been conducted by the Korea Centers for Disease Control and Prevention (KCDC). This nationally representative cross-sectional survey includes approximately 10 000 individuals each year as a survey sample and collects information on socioeconomic status, health-related behaviours, quality of life, healthcare utilization, anthropometric measures, biochemical and clinical profiles for non-communicable diseases and dietary intakes with three component surveys: health interview, health examination and nutrition survey. The health interview and health examination are conducted by trained staff members, including physicians, medical technicians and health interviewers, at a mobile examination centre, and dieticians’ visits to the homes of the study participants are followed up. KNHANES provides statistics for health-related policies in Korea, which also serve as the research infrastructure for studies on risk factors and diseases by supporting over 500 publications. KCDC has also supported researchers in Korea by providing annual workshops for data users. KCDC has published the Korea Health Statistics each year, and microdata are publicly available through the KNHANES website (http://knhanes.cdc.go.kr).

Scaling of adult body weight to height across sex and race/ethnic groups: relevance to BMI

BACKGROUND

Body mass index (BMI) is formulated on the assumption that body weight (BW) scales to height with a power of 2 (BW∝height(2)), independent of sex and race-ethnicity. Powers differing from 2 are observed in studies of selected samples, thus raising the question if BMI is a generalizable metric that makes BW independent of height across populations.

OBJECTIVES

The objectives were to test the hypothesis that adult BW scales to height with a power of 2 independent of sex and race-ethnicity and to advance an understanding of BMI as a measure of shape by extending allometric analyses to waist circumference (WC).

DESIGN

We conducted cross-sectional subject evaluations, including body composition, from the NHANES and the Korean NHANES (KNHANES). Variations of the allometric model (Y = αX(β)) were used to establish height scaling powers (β ± SE) across non-Hispanic white and black, Mexican American, and Korean men and women.

RESULTS

Exploratory analyses in population samples established age and adiposity as important independent determinants of height scaling powers (i.e., β). After age and adiposity in the next series of analyses were controlled for, BW scaling powers were nonsignificantly different between race/ethnic groups within each sex group; WC findings were similar in women, whereas small but significant between-race differences were observed in the men. Sex differences in β values were nonsignificant except for BW in non-Hispanic blacks and WC in Koreans (P < 0.05). Nationally representative powers for BW were (NHANES/KNHANES) 2.12 ± 0.05/2.11 ± 0.06 for men and 2.02 ± 0.04/1.99 ± 0.06 for women and for WC were 0.66 ± 0.03/0.67 ± 0.05 for men and 0.61 ± 0.04/0.56 ± 0.05 for women.

CONCLUSIONS

Adult BW scales to height with a power of ∼2 across the 8 sex and race/ethnic groups, an observation that makes BMI a generalizable height-independent measure of shape across most populations. WC also follows generalizable scaling rules, a finding that has implications for defining body shape in populations who differ in stature.

Scaling of adult regional body mass and body composition as a whole to height: Relevance to body shape and body mass index

OBJECTIVES

Adult body mass (MB) empirically scales as height (Ht) squared (MB ∝ Ht(2) ), but does regional body mass and body composition as a whole also scale as Ht(2) ? This question is relevant to a wide range of biological topics, including interpretation of body mass index (BMI).

METHODS

Dual-energy X-ray absorptiometry (DXA) was used to quantify regional body mass [head (MH), trunk, arms, and legs] and whole-body composition [fat, lean soft tissue (LST), and bone mineral content (BMC)] in non-Hispanic (NH) white, NH black, Mexican American, and Korean adults participating in the National Health and Nutrition Examination Survey (NHANES; n = 17,126) and Korean NHANES (n = 8,942). Regression models were developed to establish Ht scaling powers for each measured component with adjustments for age and adiposity.

RESULTS

Exploratory analyses revealed a consistent scaling pattern across men and women of the four population groups: regional mass powers, head (∼0.8-1) < arms and trunk (∼1.8-2.3) < legs (∼2.3-2.6); and body composition, LST (∼2.0-2.3) < BMC (∼2.1-2.4). Small sex and population differences in scaling powers were also observed. As body mass scaled uniformly across the eight sex and population groups as Ht(∼2) , tall and short subjects differed in body shape (e.g., MH/MB ∝ Ht(-∼1) ) and composition.

CONCLUSIONS

Adult human body shape and relative composition are a function of body size as represented by stature, a finding that reveals a previously unrecognized phenotypic heterogeneity as defined by BMI. These observations provide new pathways for exploring mechanisms governing the interrelations between adult stature, body morphology, biomechanics, and metabolism.

Interactions between dietary calcium intake and bone mineral density or bone geometry in a low calcium intake population (KNHANES IV 2008-2010)

CONTEXT

Little is known about the interactions between dietary calcium intake and bone strength parameters in populations or areas with low calcium intake.

OBJECTIVE

The objective of the study was to investigate the relationship between dietary calcium intake and bone mineral density (BMD) or bone geometry in an Asian population with low calcium intake.

DESIGN AND SETTING

This was a cross-sectional study of data from the Korea National Health and Nutrition Examination Survey, 2008-2010.

PARTICIPANTS

A total of 3448 men and 3812 women older than 50 years were stratified by daily dietary calcium intake: less than 400 mg/d, 400-799 mg/d, 800-1199 mg/d, and 1200 mg/d or greater.

MAIN OUTCOME MEASURES

BMD was measured by dual-energy X-ray absorptiometry and the geometric index was calculated.

RESULTS

Mean daily calcium intake was 470 mg/d in this population. BMD in the lumbar spine (both sexes) and femoral neck (women) was significantly lower only when calcium intake was less than 400 mg/d. In men, femoral neck and total hip BMD was positively related to calcium intake up to 1200 mg/d. Calcium intake less than 400 mg/d was negatively related to femoral cortical thickness and buckling ratio. These interactions disappeared when the 25-hydroxyvitamin D level was 30 ng/mL or greater in men and 20 ng/mL or greater in women.

CONCLUSIONS

Low calcium intake was significantly related with low BMD and increased risk of osteoporosis. However, the association between calcium and BMD was not consistently linear, and a sufficient vitamin D level appears to compensate for the negative influences of low calcium intake on bone.

The Official Positions of the International Society for Clinical Densitometry: body composition analysis reporting

Dual-energy x-ray absorptiometry (DXA) measurements of body composition increasingly are used in the evaluation of clinical disorders, but there has been little guidance on how to effectively report these measures. Uniformity in reporting of body composition measures will aid in the diagnosis of clinical disorders such as obesity, sarcopenia, and lipodystrophy. At the 2013 International Society for Clinical Densitometry Position Development Conference on body composition, the reporting section recommended that all DXA body composition reports should contain parameters of body mass index, bone mineral density, BMC, total mass, total lean mass, total fat mass, and percent fat mass. The inclusion of additional measures of adiposity and lean mass are optional, including visceral adipose tissue, appendicular lean mass index, android/gynoid percent fat ratio, trunk to leg fat mass ratio, lean mass index, and fat mass index. Within the United States, we recommend the use of the National Health and Nutrition Examination Survey 1999-2004 body composition dataset as an age-, gender-, and race-specific reference and to calibrate BMC in 4-compartment models. Z-scores and percentiles of body composition measures may be useful for clinical interpretation if methods are used to adjust for non-normality. In particular, DXA body composition measures may be useful for risk-stratification of obese and sarcopenic patients, but there needs to be validation of thresholds to define obesity and sarcopenia. To summarize, these guidelines provide evidence-based standards for the reporting and clinical application of DXA-based measures of body composition.

Development and validation of osteoporosis risk-assessment model for Korean postmenopausal women

Currently, dual-energy X-ray absorptiometry (DXA) is the gold standard for detecting osteoporosis, but is not recommended for general population screening. Therefore, this study aims to develop an osteoporosis risk-assessment model to identify high-risk individuals among Korean postmenopausal women. Data from 1,209 and 1,046 postmenopausal women who participated in the 2009 and 2010 Korean National Health and Nutrition Examination Survey, respectively, were used for development and validation of an osteoporosis risk-assessment model. Osteoporosis was defined as T score less than or equal to -2.5 at either the femoral neck or lumbar spine. Performance of the candidate models and the Osteoporosis Self assessment Tool for Asians (OSTA) were compared with respect to sensitivity, specificity, and area under the receiver operating characteristics curve (AUC). To compare the developed Korean Osteoporosis Risk-Assessment Model (KORAM) with OSTA, a net reclassification improvement was further calculated. In the development dataset, the prevalence of osteoporosis was 33.9 %. KORAM, consisting of age, weight, and hormone therapy, had a sensitivity of 91.2 %, a specificity of 50.6 %, and an AUC of 0.709 with a specific cut-off score of -9. Comparable results were shown in the validation dataset: sensitivity 84.8 %, specificity 51.6 %, and AUC 0.682. Additionally, risk categorization with KORAM showed improved reclassification over that of OSTA from 7.4 to 41.7 %. KORAM can be easily used as a pre-screening tool to identify candidates for DXA tests. Further studies investigating cost-effectiveness and replicability in other datasets are required to establish the clinical utility of KORAM.