Obesity, coronary heart disease risk factors and diabetes in Chinese: an approach to the criteria of obesity in the Chinese population

Global prevalence of obesity in the older adults: A meta-analysis

Objective

Obesity is a chronic and complex disease defined as the excessive accumulation of body fat and is one of the leading public health problems in developed and developing countries. Due to the importance of obesity, this study was conducted to investigate the prevalence of obesity in the older adults.

Study design

meta-analysis.

Methods

In this study, systematic review and meta-analysis of study data on the prevalence of obesity in the older adults in the world using keywords including: prevalence, outbreak, Body Mass Index, BMI, obesity, Elderly, aged, older adult, in Science Direct databases, Scopus, PubMed, Web of Science, Iran Doc, Mag Iran, SID and Google Scholar search engine were extracted without time limit until August 2020. The target population under study is the world's elderly, and obesity means a BMI≥30. The Random Effects Model was used to perform the analysis and, Comprehensive Meta-Analysis Software version 2.0 was used for data analysis.

Results

In review 44 studies with a total sample size of 45,745,944 prevalence of obesity in the older adults of the world; In a meta-analysis of 25.3 % (95 % CI: 21.9-29). It was found that the highest prevalence of obesity in the older adults in South America with 40.4 % (95 % CI: 12.5-76.4). In addition, continental Europe with 33.6 % (95 % confidence interval: 24.1-44.5). The meta-regression results showed an increasing trend in the prevalence of obesity in the older adults in the world with an increasing sample size and a decreasing trend with increasing the study (P < 0.05).

Conclusion

Given that the prevalence of obesity in the older adults is high, health policymakers must take adequate measures to increase public awareness about the risks of obesity in the older adults.

The relationship between chrononutrition profile, social jet lag and obesity: A cross-sectional study of Chinese college students

This study aimed to investigate the associations between chrononutrition profile, social jet lag (SJL) with obesity-related indicators (body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHTR), and percentage of body fat (PBF)). This cross-sectional study was conducted among college students in a university in Hunan Province, China, from 14 September 2023 to 8 June 2024. This study employed the Chrononutrition Profile - Questionnaire (CP-Q) along with physical examinations. SJL was defined as time difference of midpoint of sleep between the workdays and freedays. Sleep-corrected SJL (SJLsc) is the absolute difference between the sleep onset on free days and workdays. Average evening latency is the time between the last meal of the day and bedtime. Eating jet lag is the difference in the midpoint of the eating window between workdays and freedays. Logistic regression was utilized to assess the associations between chrononutrition profile, SJL, and obesity-related indicators among college students. A total of 805 participants were recruited, of which 695 have complete data after excluding those who did not meet the inclusion criteria. After adjusting for potential covariates, average evening latency <4 h was related with lower risk of high BMI, WC, and PBF [OR (95% CI) = 0.435 (0.285-0.663), 0.508 (0.305-0.848), 0.564 (0.402-0.792), respectively]. Average eating window >12 h was associated with a lower risk of high BMI, WC, and PBF [OR (95% CI) = 0.511 (0.327-0.800), 0.485 (0.277-0.851), 0.651 (0.456-0.930), respectively]. Last eating occasion jet lag >1 h was a higher risk of high PBF [OR (95% CI) = 1.554 (1.018-2.371)]. SJLsc > 1 h was associated with high PBF [OR (95% CI) = 1.527 (1.073-2.174)]. Circadian rhythm disruptions, including SJL and eating jet lag, are prevalent among college students. Long eating window, short evening latency, is associated with low risk of obesity, while short sleep duration, last eating occasion jet lag and larger SJLsc were associated with higher risk of obesity among youths.

Biofluid-Derived Exosomal LncRNAs: Their Potential in Obesity and Related Comorbidities

Obesity has escalated into a critical global health crisis, tripling in prevalence since the mid-1970s. This increase mirrors the rise in metabolic-associated diseases such as type 2 diabetes (T2D) and its complications, certain cancers, and cardiovascular conditions. While substantial research efforts have enriched our understanding and led to the development of innovative management strategies for these diseases, the suboptimal response rates of existing therapies remain a major obstacle to effectively managing obesity and its associated conditions. Over the years, inter-organ communication (IOC) has emerged as a crucial factor in the development and progression of metabolic disorders. Exosomes, which are nano-sized vesicular couriers released by cells, play a significant role in this communication by transporting proteins, lipids, and nucleic acids across cellular landscapes. The available evidence indicates that exosomal RNAs present in biofluids such as blood, urine, milk, vitreous humor (VH), and cerebrospinal fluid (CSF) are altered in numerous diseases, suggesting their diagnostic and therapeutic potential. Long non-coding RNAs contained in exosomes (exo-lncRNAs) have attracted considerable interest, owing to their ability to interact with critical components involved in a multitude of metabolic pathways. Recent studies have found that alterations in exo-lncRNAs in biofluids correlate with several metabolic parameters in patients with metabolic-associated conditions; however, their exact roles remain largely unclear. This review highlights the diagnostic and therapeutic potential of exosomal lncRNAs in obesity and its associated conditions, emphasizing their role in IOC and disease progression, aiming to pave the way for further research in this promising domain.

Eating time variation from weekdays to weekends and its association with dietary intake and BMI in different chronotypes: findings from National Health and Nutrition Examination Survey (NHANES) 2017-2018

Evidence suggests that differences in meal timing between weekends and weekdays can disrupt the body's circadian rhythm, leading to a higher BMI. We aimed to investigate the associations between mealtime variation from weekdays to weekends (eating midpoint jetlag), dietary intake and anthropometric parameters, based on individuals' chronotype. The study utilised data from National Health and Nutrition Examination Survey 2017-2018. Food consumption was estimated by weighted average of participants' food intake on weekdays and weekends. Eating midpoint jetlag, defined as the difference between the midpoint of the first and last mealtimes on weekends and weekdays, was calculated. Chronotype was assessed by participants' mid-sleep time on weekends, adjusted for sleep debt. Linear regression analysis was conducted to investigate the associations between variables. The sample was categorised into chronotype tertiles. Among individuals in the third chronotype tertile, there was a positive association between eating midpoint jetlag and BMI (β = 1·2; 95 % CI (1·13, 1·27)). Individuals in the first tertile showed a positive association between eating midpoint jetlag and energy (β = 96·9; 95 % CI (92·9, 101·7)), carbohydrate (β = 11·96; 95 % CI (11·2, 12·6)), fat (β = 3·69; 95 % CI (3·4, 3·8)), cholesterol (β = 32·75; 95 % CI (30·9, 34·6)) and sugar (β = 8·84; 95 % CI (8·3, 9·3)) intake on weekends. Among individuals with an evening tendency, delaying meals on weekends appears to be linked to a higher BMI. Conversely, among individuals with a morning tendency, eating meals later on weekends is associated with higher energetic intake on weekends.

Association of B vitamin intake and total homocysteine levels with all-cause and cause-specific mortality in central obesity

OBJECTIVES

Future primary prevention strategies may benefit from understanding the connection between mortality in individuals with central obesity and modifiable lifestyle factors like dietary intake. This study sought to determine whether there was a separate relationship between folate, vitamin B6, and vitamin B12 intake and all-cause and cause-specific mortality in the US population with central obesity.

METHODS

The study analyzed data from the National Health and Nutrition Examination Survey between 1999 and 2016. Using the Cox proportional hazards model, the association between dietary intake of B vitamins and all-cause and cause-specific mortality was examined. A total of 7718 adults with central obesity were enrolled, with a mean age of 49.87 (SD = 0.25) y at baseline.

RESULTS

Folate intake was independently associated with a decreased incidence of all-cause mortality (adjusted hazard ratio = 0.71; 95% CI, 0.58-0.87). Furthermore, higher intake of vitamin B6 and vitamin B12 was inversely correlated with cardiovascular disease mortality (adjusted hazard ratio = 0.63; 95% CI, 0.40-0.98; and adjusted hazard ratio = 0.44; 95% CI, 0.29-0.65, respectively) and the finding reveal an interaction between homocysteine and vitamin B12 and folate on All-cause mortality CONCLUSIONS: The findings of this study suggest that vitamin B12 and folate intake may be protective factors in individuals with central obesity. It is important to consider both their total homocysteine level and body mass index in conjunction with these nutrients. Further research is needed to validate these findings.

Central obesity as assessed by conicity index and a-body shape index associates with cardiovascular risk factors and mortality in kidney failure patients

Background

Anthropometric indices of central obesity, waist circumference (WC), conicity index (CI), and a-body shape index (ABSI), are prognostic indicators of cardiovascular (CV) risk. The association of CI and ABSI with other CV risk indices, markers of nutritional status and inflammation, and clinical outcomes in chronic kidney disease (CKD) stage 5 (CKD5) patients was investigated.

Methods

In a cross-sectional study with longitudinal follow up of 203 clinically stable patients with CKD5 (median age 56 years; 68% males, 17% diabetics, 22% with CV disease, and 39% malnourished), we investigated CI and ABSI and their associations with atherogenic index of plasma (AIP), Framingham CV risk score (FRS), Agatston scoring of coronary artery calcium (CAC) and aortic valve calcium (AVC), handgrip strength (HGS), high sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6). CV events (CVE) and all-cause mortality during up to 10-years follow up were analyzed by multivariate survival analysis of restricted mean survival time (RMST).

Results

Chronic kidney disease patients with middle and highest CI and ABSI tertiles (indicating greater abdominal fat deposition), compared to those with the lowest CI and ABSI tertiles, tended to be older, more often men and diabetic, had significantly higher levels of hsCRP, IL-6, AIP, FRS, CAC and AVC scores. CI and ABSI were positively correlated with CAC, FRS, AIP, hsCRP and IL-6. Both CI and ABSI were negatively correlated with HGS. In age-weighted survival analysis, higher CI and ABSI were associated with higher risk of CVE (Wald test = 4.92, p = 0.027; Wald test = 4.95, p = 0.026, respectively) and all-cause mortality (Wald test = 5.24, p = 0.022; Wald test = 5.19, p = 0.023, respectively). In RMST analysis, low vs. high and middle tertiles of CI and ABSI associated with prolonged CVE-free time and death-free time, and these differences between groups increased over time.

Conclusion

Abdominal fat deposit indices, CI and ABSI, predicted CV outcomes and all-cause mortality, and were significantly associated with the inflammatory status in CKD patients.

Secular trends in the prevalence of abdominal obesity among Chinese adults with normal weight, 1993-2015

A considerable chronic disease burden existed in people with normal body mass index (BMI), it is imperative to study the prevailing trends in abdominal obesity among Chinese people with normal BMI. Hence, we aimed to analyze updated prevalence data on abdominal obesity trends among Chinese adults with a normal BMI. We used data from the China Health and Nutrition Survey (CHNS) conducted between 1993 and 2015. Abdominal obesity is defined as waist circumference (WC) ≥ 90 cm for men and ≥ 80 cm for women following the International Diabetes Federation recommendations for Asians. Over the 23-year period, the age-standardized mean WC values showed a significant increasing trend among Chinese adults with BMI < 25 kg/m², with the mean value increased from 74.0 cm to 78.5 cm (P for trend < 0.0001). During the period of 1993-2015, the age-standardized prevalence of abdominal obesity increased from 12.1 to 26.0% (P for trend < 0.0001). Significant increases were observed in both sexes, all age groups, rural and urban residents, and all educational attainment groups (all P for trends < 0.0001), with a greater relative increase noted among men, younger participants, and rural residents. Similar significant trends were noted when a more stringent BMI < 23 kg/m² cut point (Asian cut point) was applied. A low magnitude of overlap existed between abdominal obesity and general obesity, irrespective of the criteria used. The mean WC and the prevalence of abdominal obesity among Chinese adults with normal BMI increased continuously from 1993 to 2015. The upward trends were noted in both sexes, all age groups, rural and urban regions, and all educational attainment groups. Our estimates emphasize the importance of adding WC in addition to BMI as measures to monitor obesity prevalence.

Anthropometric Indicators as a Tool for Diagnosis of Obesity and Other Health Risk Factors: A Literature Review

Obesity is characterized by the accumulation of an excessive amount of fat mass (FM) in the adipose tissue, subcutaneous, or inside certain organs. The risk does not lie so much in the amount of fat accumulated as in its distribution. Abdominal obesity (central or visceral) is an important risk factor for cardiovascular diseases, diabetes, and cancer, having an important role in the so-called metabolic syndrome. Therefore, it is necessary to prevent, detect, and appropriately treat obesity. The diagnosis is based on anthropometric indices that have been associated with adiposity and its distribution. Indices themselves, or a combination of some of them, conform to a big picture with different values to establish risk. Anthropometric indices can be used for risk identification, intervention, or impact evaluation on nutritional status or health; therefore, they will be called anthropometric health indicators (AHIs). We have found 17 AHIs that can be obtained or estimated from 3D human shapes, being a noninvasive alternative compared to X-ray-based systems, and more accessible than high-cost equipment. A literature review has been conducted to analyze the following information for each indicator: definition; main calculation or obtaining methods used; health aspects associated with the indicator (among others, obesity, metabolic syndrome, or diabetes); criteria to classify the population by means of percentiles or cutoff points, and based on variables such as sex, age, ethnicity, or geographic area, and limitations.

"Have You Taken the A4 Challenge?" Correlates and Impact of a Thin Ideal Expression From Chinese Social Media

In three studies, we assessed knowledge, correlates, and effects of the A4 challenge, an expression of the thin ideal from Chinese social media. In Study 1, gender differences in familiarity with the A4 challenge were assessed among 225 women and 151 men. Compared to men, women and female peers from participant social networks were more familiar with and likely to have taken the challenge themselves. In Study 2, body image experiences of women who passed the A4 challenge (N = 45) and average weight peers who did not pass the challenge (N = 75) were assessed. The former group reported fewer weight concerns and less social pressure to lose weight but no group differences were observed with respect to binge-eating, dieting, or other compensatory weight loss behaviors. As such, eating disorder symptoms did not account for the experience of passing the A4 challenge. In Study 3, changes in state body dissatisfaction were assessed among 205 women randomly assigned to view images of (1) thin peers successfully passing the challenge vs. (2) thin or (3) average size controls. The absence of condition differences in post-exposure state body dissatisfaction indicated exposure to A4 challenge portrayals per se did not cause increases in negative appearance self-evaluations for women in general. However, among women who were exposed to A4 challenge images, but not control group women exposure to other images, trait body dissatisfaction predicted increased post-exposure state dissatisfaction, independent of pre-exposure state dissatisfaction. Implications are discussed in relation to effects of exposure to the A4 challenge and conceptualizing the task as a "challenge."

Obesity as a "self-regulated epidemic": coverage of obesity in Chinese newspapers

OBJECTIVE

The aim of this study was to investigate how obesity was covered in Chinese newspapers from 1999 to 2018, demonstrating the trends and the characteristics of obesity-related news.

METHODS

Content analysis was conducted to analyze a total of 358 news articles spanning two decades (1999-2018). We explored how Chinese newspapers portrayed obesity in terms of the evidence/sources cited in articles, its impacts, drivers/causes, and solutions; and how such portrayals have evolved over time. We further compared the articles across different types of newspapers (government-sponsored vs. commercial), two subpopulations (children vs. adults), and periods of time (1999-2008 vs. 2009-2018).

RESULTS

Results showed that medical experts' interviews and statistics were the two most cited types of evidence in the articles. When discussing causes and solutions of obesity, factors pertaining to personal lifestyles were mentioned most frequently. Compared to psychological and social impacts, physical health risk was stressed more often. Compared with commercial newspapers, government-funded newspapers mentioned societal drivers of obesity and suggested reforming schools more frequently. Such differences were also found between coverage of child obesity and adult obesity. Our research, furthermore, revealed significant differences of media coverage of obesity across the two decades.

CONCLUSIONS

Our findings indicate that obesity was generally depicted as a "self-regulated epidemic" in Chinese newspapers. Although the revealed causes and consequences of obesity are evidently related to individual factors, more attention should be directed to the roles that the government, media, and the society can play in preventing obesity and mitigating related social/economic burden.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Ethno-essentialisms of the self: A critique of the cultural scripting of obesity in Japan

In challenging the 'validity' of the body mass index (BMI), the construct of metabolic syndrome has been used to comprehend how obesity affects Japanese people. This article is grounded in an adaptation of the 'sexual scripting theory' (Gagnon and Simon, 2005) and proposes the concept of 'ethno-essentialisms of the self' to explore the cultural scripts underpinning the development of metabolic syndrome. Ethno-essentialisms of the self indicate a dialectical relationship between a Japanese healthy self and a non-Japanese unhealthy Other, where ethno-racial susceptibilities might make a Japanese self prone to develop metabolic-related diseases. Despite these susceptibilities, Japanese 'biopedagogy' (Wright, 2009) to control bodyweight is oriented by a proper daily calculation of food consumption in relation to calorie-burning. Biopedagogy in the form of food and nutrition education has largely translated into unyielding efforts to (re)traditionalise eating habits to prevent the supposed Westernisation of Japanese food. Overall, medical knowledge serves to propagate ethno-essentialisms of the self, whose unintended consequence could be 'clinical iatrogenic disease' (Illich, 1976).

Tri-Ponderal Mass Index Reference Values for Screening Metabolic Syndrome in Children and Adolescents: Results From Two National-Representative Cross-Sectional Studies in China and America

INTRODUCTION

To ascertain the possible cut point of tri-ponderal mass index (TMI) in discriminating metabolic syndrome (MetS) and related cardio-metabolic risk factors in Chinese and American children and adolescents.

METHODS

A total of 57,201 Chinese children aged 7-18 recruited in 2012 and and 10,441 American children aged 12-18 from National Health and Nutrition Examination Survey (NHANES 2001-2014) were included to fit TMI percentiles. Participants were randomly assigned to a derivation set (75%) and validation set (25%). The cut points of TMI with the lowest misclassification rate under the premise of the highest area under curves (AUC) were selected for each sex, which were additionally examined in the validation set. All of data analysis was conducted between September and December in 2019.

RESULTS

TMI showed good capacity on discriminating MetS, with AUC of 0.7658 (95% CI: 0.7544-0.7770) to 0.8445 (95% CI: 0.8349-0.8537) in Chinese and 0.8871 (95% CI: 0.8663-0.9056) to 0.9329 (95% CI: 0.9166-0.9469) in American children. The optimal cut points were 14.46 kg/m³ and 13.91 kg/m³ for Chinese boys and girls, and 17.08 kg/m³ and 18.89 kg/m³ for American boys and girls, respectively. The corresponding misclassification rates were 17.1% (95% CI: 16.4-17.8) and 11.2% (95% CI: 9.9-12.6), respectively. Performance of these cut points were also examined in the validation set (sensitivity 67.7%, specificity 82.4% in Chinese; sensitivity 84.4%, specificity 88.7% in American children).

CONCLUSIONS

A sex- and ethnicity- specific single cut point of TMI could be used to distinguish MetS and elevated risk of cardio-metabolic factors in children and adolescents.

Wage Penalties or Wage Premiums? A Socioeconomic Analysis of Gender Disparity in Obesity in Urban China

Global obesity as a major public health problem has increased at pandemic rate, with men often outpacing women. Survey data show that the overall prevalence of obesity is higher among women than men, yet in high-income developed countries, the prevalence of overweight is higher among men than women. The differential impact of different economic stages has prompted research in transition economies such as China. Using an instrumental variable approach based on a sample of 13,574 individuals from nine provinces in the Chinese Household Income Project (CHIP), we find a 7% excess-weight premium in wages for overweight men and a 4.6% penalty for overweight women, compared to their healthy-weight peers. We also find an inverse u-shaped association between the body mass index (BMI) and logarithm of monthly income for men, with an implied optimum above the threshold of obesity, while women are better off the slimmer they are. The excess-weight premium in wages for Chinese urban men might be associated with entrenched business practices of excessive dining and drinking associated with senior positions. Policies aimed at reducing obesity in China must be adapted to its unique sociocultural context in order to have gender-differentiated effects.

Gestational weight gain across continents and ethnicity: systematic review and meta-analysis of maternal and infant outcomes in more than one million women

BACKGROUND

The association between Institute of Medicine (IOM) guidelines and pregnancy outcomes across ethnicities is uncertain. We evaluated the associations of gestational weight gain (GWG) outside 2009 IOM guidelines, with maternal and infant outcomes across the USA, western Europe and east Asia, with subgroup analyses in Asia. The aim was to explore ethnic differences in maternal prepregnancy body mass index (BMI), GWG and health outcomes across these regions.

METHODS

Systematic review, meta-analysis and meta-regression of observational studies were used for the study. MEDLINE, MEDLINE In-Process, Embase and all Evidence-Based Medicine (EBM) Reviews were searched from 1999 to 2017. Studies were stratified by prepregnancy BMI category and total pregnancy GWG. Odds ratio (ORs) 95% confidence intervals (CI) applied recommended GWG within each BMI category as the reference. Primary outcomes were small for gestational age (SGA), preterm birth and large for gestational age (LGA). Secondary outcomes were macrosomia, caesarean section and gestational diabetes.

RESULTS

Overall, 5874 studies were identified and 23 were included (n = 1,309,136). Prepregnancy overweight/obesity in the USA, Europe and Asia was measured at 42%, 30% and 10% respectively, with underweight 5%, 3% and 17%. GWG below guidelines in the USA, Europe and Asia was 21%, 18% and 31%, and above was 51%, 51% and 37% respectively. Applying regional BMI categories in Asia showed GWG above guidelines (51%) was similar to that in the USA and Europe. GWG below guidelines was associated with a higher risk of SGA (USA/Europe [OR 1.51; CI 1.39, 1.63]; Asia [1.63; 1.45, 1.82]) and preterm birth (USA/Europe [1.35; 1.17, 1.56]; Asia [1.06; 0.78, 1.44]) than GWG within guidelines. GWG above guidelines was associated with a higher risk of LGA (USA/Europe [1.93; 1.81, 2.06]; Asia [1.68; 1.51 , 1.87]), macrosomia (USA/Europe [1.87; 1.70, 2.06]; Asia [2.18; 1.91, 2.49]) and caesarean (USA/Europe [1.26; 1.21, 1.33]; Asia [1.37; 1.30, 1.45]). Risks remained elevated when regional BMI categories were applied for GWG recommendations. More women in Asia were categorised as having GWG below guidelines using World Health Organization (WHO) (60%) compared to regional BMI categories (16%), yet WHO BMI was not accompanied by increased risks of adverse outcomes.

CONCLUSIONS

Women in the USA and western Europe have higher prepregnancy BMI and higher rates of GWG above guidelines than women in east Asia. However, when using regional BMI categories in east Asia, rates of GWG above guidelines are similar across the three continents. GWG outside guidelines is associated with adverse outcomes across all regions. If regional BMI categories are used in east Asia, IOM guidelines are applicable in the USA, western Europe and east Asia.

Visceral, general, abdominal adiposity and atherogenic index of plasma in relatively lean hemodialysis patients

Background

Obesity is a well-established risk factor for atherosclerosis. However, it is unknown which measure of adiposity best relates to atherosclerosis in relatively lean maintenance hemodialysis (MHD) patients. We aimed to explore and compare the associations between different adiposity indices reflecting general, abdominal, visceral adiposity and arteriosclerosis risk with atherogenic index of plasma(AIP) in relatively lean MHD patients.

Methods

We conducted a multicenter, cross-sectional study in Guizhou Province, Southwest China. General/abdominal adiposity indices like body mass index (BMI), waist circumference(WC), waist-height ratio(WHtR), conicity index (Ci) and visceral obesity indices including visceral adiposity index (VAI), lipid accumulation product (LAP) and the hypertriglyceridemic waist phenotype (HW phenotype) were recorded. Univariate and multivariate linear regression models were used.

Results

All adiposity indices correlated positively with AIP in univariate analysis both in men and women except for Ci. After adjustment for age and traditional atherosclerosis risk factors, BMI, WC, WHtR, VAI and LAP still had associations with AIP both in men (β = 0.265, 0.153, 0.16, 0.788 and 0.74, respectively, all P < 0.001) and women (β = 0.34,0.199, 0.21, 0.83 and 0.74, respectively, all P < 0.001). After further adjustment for BMI, associations between AIP and VAI, LAP remained significant, but associations between WC, WHtR and AIP disappeared.

Conclusions

The HW phenotype, VAI, and LAP, validated and convenient markers of visceral obesity, were superior to classical anthropometric general/ abdominal adiposity indices for atherosclerosis risk assessment, especially in relatively lean MHD patients aged 40 years or older.

Body mass index and type 2 diabetes in Thai adults: defining risk thresholds and population impacts

Background

Body mass index (BMI) cut-off values (>25 and >30) that predict diabetes risk have been well validated in Caucasian populations but less so in Asian populations. We aimed to determine the BMI threshold associated with increased type 2 diabetes (T2DM) risk and to calculate the proportion of T2DM cases attributable to overweight and obesity in the Thai population.

Methods

Participants were those from the Thai Cohort Study who were diabetes-free in 2005 and were followed-up in 2009 and 2013 (n = 39,021). We used multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the BMI-T2DM association. We modelled non-linear associations using restricted cubic splines. We estimated population attributable fractions (PAF) and the number of T2DM incident cases attributed to overweight and obesity. We also calculated the impact of reducing the prevalence of overweight and obesity on T2DM incidence in the Thai population.

Results

Non-linear modelling indicated that the points of inflection where the BMI-T2DM association became statistically significant compared to a reference of 20.00 kg/m² were 21.60 (OR = 1.27, 95% CI 1.00–1.61) and 20.03 (OR = 1.02, 95% CI 1.02–1.03) for men and women, respectively. Approximately two-thirds of T2DM cases in Thai adults could be attributed to overweight and obesity. Annually, if prevalent obesity was 5% lower, ~13,000 cases of T2DM might be prevented in the Thai population.

Conclusions

A BMI cut-point of 22 kg/m², one point lower than the current 23 kg/m², would be justified for defining T2DM risk in Thai adults. Lowering obesity prevalence would greatly reduce T2DM incidence.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4708-7) contains supplementary material, which is available to authorized users.

Effects of the body mass index (BMI) on the surgical outcomes of laparoscopic fundoplication for gastro-esophageal reflux disease: a propensity score-matched analysis

PURPOSE

In the present study, we examined how the body mass index (BMI) affected the outcomes of laparoscopic fundoplication for GERD in patients, whose backgrounds were matched in a propensity score-matched analysis.

METHODS

We divided the patients into two groups (BMI <25 kg/m² and BMI ≥25 kg/m²). The following background information was matched for the propensity score-matched analysis: sex, age, degree of esophageal hiatal hernia, acid exposure time, and degree of reflux esophagitis. In total, 105 subjects were extracted in each group. The surgical outcomes and postoperative outcomes of patients with BMI <25 kg/m² (Group A) and those with BMI ≥25 kg/m² (Group B) were compared and examined.

RESULTS

There were no differences in the surgical procedure, intraoperative complications, or estimated blood loss (p = 0.876, p = 0.516, p = 0.438, respectively); however, the operative time was significantly prolonged in Group B (p = 0.003). The rate of postoperative recurrence in Group A was 17% (15/87 patients), while that in Group B was 11% (12/91 patients), and did not differ to a statistically significant extent (p = 0.533).

CONCLUSIONS

Although the operative time for GERD in obese patients was prolonged in comparison with non-obese patients, there was no difference in the rate of postoperative recurrence.

Prevention and Care Programs Addressing the Growing Prevalence of Diabetes in China

According to a 2010 national survey, 11 % of adults in China have diabetes, affecting 109.6 million individuals. The high prevalence of diabetes has been attributed to the aging of the population, the rapid adoption of energy-dense foods, and a reduction in physical activity. Collectively, these secular changes have created an obesogenic environment that can unmask diabetes in subjects with a genetic predisposition. The growing prevalence of maternal obesity, gestational diabetes, childhood obesity, and early-onset disease can lead to premature morbidity and mortality. Rising to meet these public health challenges, researchers in China have conducted randomized studies to demonstrate the benefits of lifestyle modification in preventing diabetes (the Da Qing Study), as well as that of team-based integrated care, using multiple strategies including peer support and information technology, in order to reduce hospitalizations, cardiovascular-renal complications, and premature deaths. With growing evidence supporting the benefits of these diabetes prevention and management programs, the next challenge is to use policies and systems to scale up the implementation of these programs through raising awareness, building capacity, and providing resources to reduce the human and socioeconomic burden of diabetes.

Evaluation of a community-based behavioral weight loss program in Chinese adults: A randomized controlled trial

OBJECTIVE

Weight losses between a group of participants assigned to a weight loss program based in the community [i.e., specifically the methodology used by Weight Watchers (WW)] and a Nutrition Education (NE) control group were compared in this study.

METHODS

In this 6-month trial, 300 participants with overweight or obesity were recruited from Beijing city, China, and randomly assigned to the WW or NE group. Weight, waist circumference, and biochemical parameters were assessed at baseline and 6 months.

RESULTS

At 6 months, the majority of participants (79% for WW; 89% for NE) completed the study. WW participants lost significantly more weight than the NE group (-4.2 ± 5.6 kg vs. -0.6 ± 3.6 kg). More WW participants lost 5% or 10% of their starting weight [≥5%: 52.0% of WW participants vs. 11.3% of NE participants (odds ratio 8.15, 95% CI: 4.43-14.97)]; [≥10%: 26.0% of WW vs. 3.3% of NE participants (odds ratio 9.39, 95% CI: 3.55-24.83)]. In addition, WW participants reduced waist circumference by 3.9 ± 6.3 cm, while the NE group increased waist circumference by 0.6 ± 5.5 cm.

CONCLUSIONS

The WW program was associated with clinically significant weight loss, demonstrating its potential value as an intervention strategy, based in the community, for the treatment of obesity in China.

Ethnic Differences in the BMI-%BF Relationships between Young Japanese and Australian-Caucasian Males Living in Australia Using Dual-Energy X-ray Absorptiometry

The Body Mass Index (BMI) has been used worldwide as an indicator of fatness. However, the universal cut-off points by the World Health Organisation (WHO) classification may not be appropriate for every ethnic group when consider the relationship with their actual total body fatness (%BF). The application of population-specific classifications to assess BMI may be more relevant to public health.

Ethnic differences in the BMI-%BF relationship between 45 Japanese and 42 Australian-Caucasian males were assessed using whole body dual-energy X-ray absorptiometry (DXA) scan and anthropometry using a standard protocol.

Japanese males had significantly ( p<0.05) greater %BF at given BMI values than Australian males. When this is taken into account the newly proposed Asia-Pacific BMI classification of BMI >23 as overweight and >25 as obese may better assess the level of obesity that is associated increased health risks for this population. To clarify the current findings, further studies that compare the relationships across other Japanese populations are recommended.

Proposed cut-off values of the waist circumference for metabolic syndrome based on visceral fat volume in a Japanese population

Aim/Introduction

Waist circumference (WC) is the most important parameter for diagnosis of metabolic syndrome. The present study was carried out to obtain optimal WC cut‐off values for diagnosis of metabolic syndrome in a Japanese population based on the measurement of total intra‐abdominal visceral fat volume (VFV), which could be expected to reflect visceral obesity more precisely than visceral fat area.

Materials and Methods

A total of 405 Japanese persons undergoing health screening were investigated. visceral fat volume was calculated from the data in 700–800 computed tomography slices from the top of the liver to the floor of the pelvic cavity. Then, receiver operating characteristic analysis was used to determine the cut‐off value of the VFV/height ratio. Subsequently, the corresponding WC value was obtained by linear regression analysis.

Results

The cut‐off value of the VFV/height ratio was 2,317 cm³/m in men and 1,425 cm³/m in women. The sensitivity and specificity of the ratio were 52.9 and 86.4% in men vs 63.4 and 82.2% in women, respectively. The corresponding cut‐off value of WC was 86.0 cm in men and 80.9 cm in women.

Conclusions

The proposed cut‐off values of WC for metabolic syndrome are 85 cm in Japanese men and 80 cm in Japanese women.

Body Composition in Asians and Caucasians: Comparative Analyses and Influences on Cardiometabolic Outcomes

Within the last four decades Asia has witnessed major transformation in its population demographics, which gave rise to changes in food availability, food habits and lifestyle. A significant consequence of these changes has been the continuing rise in overweight and obesity across Asia. In parallel, there has been a significant rise in Asians in the incidence of the major chronic diseases, particularly in cardiometabolic disorders such as metabolic syndrome, type 2 diabetes, hypertension, and other cardiovascular diseases. Given that the majority of the evidence, to date, investigating the associations between adiposity and cardiometabolic disorder risk have been obtained from studies undertaken either in European or in North American Caucasians, in this chapter, we have reviewed differences in body fat content and distribution between East Asians, South Asians, and Caucasians. The evidence is consistent that the content and distribution of body fat are markedly different between the various ethnic groups. We found that Asians have a greater predisposition towards adiposity at higher BMI than in Caucasians. Moreover, at any given level of adiposity, Asians have a much greater predisposition to risk of cardiometabolic disorders than Caucasians. We therefore strongly endorse the need for different adiposity cutoffs in Asians as compared to the Caucasians. We have also reviewed the predictive abilities of the various body composition/adiposity measures in determining risk of cardiometabolic disorders in Asians.

Ethnicity-specific obesity cut-points in the development of Type 2 diabetes - a prospective study including three ethnic groups in the United Kingdom

AIMS

Conventional definitions of obesity, e.g. body mass index (BMI) ≥ 30 kg/m² or waist circumference cut-points of 102 cm (men) and 88 cm (women), may underestimate metabolic risk in non-Europeans. We prospectively identified equivalent ethnicity-specific obesity cut-points for the estimation of diabetes risk in British South Asians, African-Caribbeans and Europeans.

METHODS

We studied a population-based cohort from London, UK (1356 Europeans, 842 South Asians, 335 African-Caribbeans) who were aged 40-69 years at baseline (1988-1991), when they underwent anthropometry, fasting and post-load (75 g oral glucose tolerance test) blood tests. Incident Type 2 diabetes was identified from primary care records, participant recall and/or follow-up biochemistry. Ethnicity-specific obesity cut-points in association with diabetes incidence were estimated using negative binomial regression.

RESULTS

Diabetes incidence rates (per 1000 person years) at a median follow-up of 19 years were 20.8 (95% CI: 18.4, 23.6) and 12.0 (8.3, 17.2) in South Asian men and women, 16.5 (12.7, 21.4) and 17.5 (13.0, 23.7) in African-Caribbean men and women, and 7.4 (6.3, 8.7), and 7.2 (5.3, 9.8) in European men and women. For incidence rates equivalent to those at a BMI of 30 kg/m² in European men and women, age- and sex-adjusted cut-points were: South Asians, 25.2 (23.4, 26.6) kg/m²; and African-Caribbeans, 27.2 (25.2, 28.6) kg/m². For South Asian and African-Caribbean men, respectively, waist circumference cut-points of 90.4 (85.0, 94.5) and 90.6 (85.0, 94.5) cm were equivalent to a value of 102 cm in European men. Waist circumference cut-points of 84.0 (74.0, 90.0) cm in South Asian women and 81.2 (71.4, 87.4) cm in African-Caribbean women were equivalent to a value of 88 cm in European women.

CONCLUSIONS

In prospective analyses, British South Asians and African-Caribbeans had equivalent diabetes incidence rates at substantially lower obesity levels than the conventional European cut-points.

Comparison of lipid accumulation product with body mass index as an indicator of hypertension risk among Mongolians in China

OBJECTIVE

To compare associations of lipid accumulation product (LAP) and body mass index (BMI) with risk of hypertension.

METHODS

Demographic characteristics, blood pressure and body measurements were obtained, blood lipids and fast plasma glucose were examined, BMI and LAP were calculated for 2589 Mongolians. Multiple linear model and covariance analysis was used to analyze the relationship between LAP and blood pressure levels, multivariate logistic analysis was used to analyze the association between BMI and LAP and hypertension.

RESULTS

LAP and BMI were all significantly higher in hypertensives than in normotensives in both genders. Multivariate adjusted mean levels of SBP and DBP increased with increased LAP and there was a linear association between LAP and blood pressure. LAP had a stronger association with risk of hypertension compared with BMI, linear trend between LAP and risks of hypertension was better than that between BMI and risks of hypertension in males. Compared to the first quartile, the odds ratios [95% confidence intervals (95% CIs)] of hypertension associated with the second, third and fourth quartiles of LAP were 1.85(1.23,2.79), 2.20(1.47,3.28), 4.21(2.78,6.38) in males; compared to the first quartile, the odds ratios (95% CIs) of hypertension associated with the second, third and fourth quartiles of BMI were 0.93(0.62,1.38), 1.23(0.83,1.84), 2.80(1.86,4.21) in males.

CONCLUSION

LAP was more closely associated with risk of hypertension than BMI in Mongolian males, this study suggested that LAP might be a preferred anthropometry measurement to predict risk of hypertension in males. Future prospective cohort studies should be conducted to test the causal relationship between LAP and the risk of hypertension in Mongolian population.

Ethnicity and the association between anthropometric indices of obesity and cardiovascular risk in women: a cross-sectional study

OBJECTIVES

The objectives of this study were to determine whether the cross-sectional associations between anthropometric obesity measures, body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR), and calculated 10-year cardiovascular disease (CVD) risk using the Framingham and general CVD risk score models, are the same for women of Australian, UK and Ireland, North European, South European and Asian descent. This study would investigate which anthropometric obesity measure is most predictive at identifying women at increased CVD risk in each ethnic group.

DESIGN

Cross-sectional data from the National Heart Foundation Risk Factor Prevalence Study.

SETTING

Population-based survey in Australia.

PARTICIPANTS

4354 women aged 20-69 years with no history of heart disease, diabetes or stroke. Most participants were of Australian, UK and Ireland, North European, South European or Asian descent (97%).

OUTCOME MEASURES

Anthropometric obesity measures that demonstrated stronger predictive ability of identifying women at increased CVD risk and likelihood of being above the promulgated treatment thresholds of various risk score models.

RESULTS

Central obesity measures, WC and WHR, were better predictors of cardiovascular risk. WHR reported a stronger predictive ability than WC and BMI in Caucasian women. In Northern European women, BMI was a better indicator of risk using the general CVD (10% threshold) and Framingham (20% threshold) risk score models. WC was the most predictive of cardiovascular risk among Asian women.

CONCLUSIONS

Ethnicity should be incorporated into CVD assessment. The same anthropometric obesity measure cannot be used across all ethnic groups. Ethnic-specific CVD prevention and treatment strategies need to be further developed.

Changes in waist circumference relative to body mass index in Chinese adults, 1993-2009

BACKGROUND

Although body mass index (BMI) and waist circumference (WC) are correlated, the relationship between WC and BMI may have changed over time.

OBJECTIVES

To describe temporal trends in BMI and WC distributions and quantify the increase in WC at a given BMI over time.

SUBJECTS/METHODS

Data on adults aged 20-59 years from two waves (1993 and 2009) of the China Health and Nutrition Survey were used in a pooled cross-sectional analysis. Quantile regression examined age-adjusted temporal trends in the distributions of BMI and WC. Linear regression examined changes in mean WC over time, adjusting for BMI, age at survey and survey year. All models were stratified by gender.

RESULTS

There was a significant increase in BMI and WC over time, particularly at the 95th quantile: on average, men had 2.8 kg m(-2) (95% confidence interval (CI): 2.4, 3.3) and women 1.5 kg m(-)(2) (95% CI: 1.1, 2.0) higher BMI in 2009 compared with their counterparts in 1993. WC increased by 9.0 cm (95% CI: 7.5, 10.1) and 5.0 cm (95% CI: 3.4, 6.6) for men and women, respectively. On average, men and women had a 3.2 cm (95% CI: 2.8, 3.7) and 2.1 cm (95% CI: 1.7, 2.5) higher WC in 2009 compared with their counterparts in 1993, holding BMI and age constant. WC adjusted for BMI increased to a larger extent among obese versus lean individuals and among younger versus older women.

CONCLUSIONS

For both genders, BMI and WC increased significantly over time, with particularly greatest increase in magnitude in the upper tail of the BMI and WC distributions. Furthermore, WC at equivalent BMIs was higher in 2009, compared with their counterparts in 1993. Our findings suggest that even if BMI remained constant from 1993 to 2009, adults in 2009 might be at increased cardiometabolic risk as a result of their higher WC.

Association between obesity and selected morbidities: a study of BRICS countries

Objective

Over the past few decades, obesity has reached epidemic proportions, and is a major contributor to the global burden of chronic diseases and disability. There is little evidence on obesity related co-morbidities in BRICS countries. The first objective is to examine the factors associated with overweight and obesity in four of the five BRICS countries (China, India, Russia and South Africa). The second is to examine the linkage of obesity with selected morbidities.

Methods

We used data from the Study on Global Ageing and Adult Health (SAGE) survey conducted by the World Health Organization (WHO) in China, India, Russia and South Africa during 2007–10. The morbidities included in the analysis are Hypertension, Diabetes, Angina, Stroke, Arthritis and Depression.

Findings

The prevalence of obesity was highest in South Africa (35%) followed by Russia (22%), China (5%) and India (3%). The prevalence of obesity was significantly higher in females as compared to males in all the countries. While the wealth quintile was associated with overweight in India and China, engaging in work requiring physical activity was associated with obesity in China and South Africa. Overweight/obesity was positively associated with Hypertension and Diabetes in all the four countries. Obesity was also positively associated with Arthritis and Angina in China, Russia and South Africa. In comparison, overweight/obesity was not associated with Stroke and Depression in any of the four countries.

Conclusion

Obesity was statistically associated with Hypertension, Angina, Diabetes and Arthritis in China, Russia and South Africa. In India, obesity was associated only with Hypertension and Diabetes.

Overweight dynamics in Chinese children and adults

China has experienced a transition from a history of undernutrition to a rapid increase in obesity. The China Health and Nutrition Survey, an ongoing longitudinal, household-based survey of urban and rural residents of nine provinces, documents these changes using measured height and weight across 53,298 observations from 18,059 participants collected from 1991 to 2011. Adult overweight (body mass index [BMI] ≥ 25 kg/m(2)) prevalence nearly tripled from 1991 (11.7%) to 2009 (29.2%), with significant cohort and age-related effects (stronger in males). Among youth, quantile regression reveals changes across the BMI distribution. By 2009, approximately 12% of children and adolescents were overweight, and 3% of 7-11-year-olds and 1% of 12-17-year-olds were obese (International Obesity Taskforce BMI 25 and 30 kg/m(2) equivalents, respectively). In 1991-2000, urbanicity was strongly and positively associated with BMI, but in 2000-2011, trends were similar across rural and urban areas. Among women, the burden has shifted to lower educated women (the reverse is true for males, as overweight was higher in men of higher education). Our findings highlight the importance of preventive measures early in the life cycle to reduce weight gain.

The emergence of cardiometabolic disease risk in Chinese children and adults: consequences of changes in diet, physical activity and obesity

Strong secular declines in physical activity, increased fat and salt intake, and increased obesity, especially abdominal obesity, mark China's recent nutrition transition. The China Health and Nutrition 2009 Survey collected anthropometry, blood pressure and fasting blood samples from more than 9,000 individuals ≥ 7 years of age. We focus on elevated blood pressure and plasma markers of diabetes, inflammation and dyslipidemia. We used international definitions of cardiometabolic risk and estimated age- and sex-specific prevalence ratios for each outcome for high waist circumference or overweight. We used logistic regression to assess each risk factor's association with diet, physical activity, overweight and abdominal obesity. Cardiometabolic risk prevalence was high in all age groups Prevalence ratios for most risk factors were nearly doubled for overweight or high waist circumference groups. Prevalence ratios were higher in younger than older adults. Low physical activity consistently predicted higher cardiometabolic risk across most outcomes and age-sex groups. The co-occurrence of overweight and high waist circumference was highly predictive of dyslipidemia, elevated glycated haemoglobin and diabetes. High prevalence of cardiometabolic risk factors and their strong association with weight status and abdominal obesity in young adults portend increases in cardiometabolic morbidity and mortality. Early interventions will be required to reverse trends.

Cutoff point of waist circumference for the diagnosis of metabolic syndrome in an Iranian population

SUMMARY

BACKGROUND

Proposed cutoffs for waist circumference (WC) in western populations may be not appropriate for Asian populations. The published data among Iranians are insufficient to address this issue. This study was designed to identify cutoffs for WC that confer increased risk of metabolic syndrome in Iranian adults living in Zanjan, a province located in the west of Tehran.

MATERIALS AND METHODS

Data of a cross-sectional sample of 3277 Iranian adults aged more than 20 years were analyzed. In the original study individual body weight, height, WC, and blood pressure were assessed and fasting plasma glucose, triglycerides, total cholesterol, low- and high-density lipoprotein cholesterol were measured. After excluding WC, existence of two or more of the remaining four risk factors of the modified NCEP III criteria for metabolic syndrome were defined as multiple risk factors. Receiver operating characteristic (ROC) analysis was used to find out the optimal cutoff values of WC to predict metabolic syndrome.

RESULTS

The cutoff level yielding the maximal sensitivity and specificity for predicting the presence of metabolic syndrome (multiple risk factors) was 87 cm in men and 82 cm in women. Cutoffs corresponding to body mass index (BMI) 25 and 30 kg/m(2) to predict metabolic syndrome were 84 and 97 cm in men and 78 and 91 cm in women, respectively.

CONCLUSIONS

Lower cutoffs for WC should be considered in the identification of Iranian population at high risk of metabolic syndrome.

Appropriate body mass index and waist circumference cutoffs for categorization of overweight and central adiposity among Uighur adults in Xinjiang

OBJECTIVE

The current overweight and central adiposity guidelines based on Western populations were not consistent with many studied based on the Asian populations. Uighur people live in Xinjiang Uighur Autonomous Region which is located in the center of Asia. Their overweight and central cutoffs were largely unknown. We aimed to identify cutoffs for body mass index (BMI; in kg/m(2)) and waist circumference (WC; in cm) for categorization of overweight and central adiposity among Uighur adults in Xinjiang.

METHODS

4767 Uighur participants were selected from the Cardiovascular Risk Survey (CRS) which was carried out from October 2007 to March 2010. The age of the participants were from 35 to 101 years old with the mean age of 50.09 years. Anthropometric data, blood pressure, serum concentration of serum total cholesterol, triglyceride, low density lipoprotein (LDL), high density lipoprotein (HDL) and fasting glucose were documented. The prevalence, sensitivity, specificity and distance on the receiver operating characteristic (ROC) curve of each BMI and waist circumference values were calculated.

RESULTS

The prevalence of hypertension, hypercholesterolemia and hypertriglyceridemia were higher with higher BMI for both men and women. The prevalence of hypertension and hypercholesterolemia were higher with higher waist circumference for both men and women. In women, the prevalence of hypertriglyceridemia was noticed to increase as the waist circumference increased. The shortest distance in the receiver operating characteristic curves for hypertension, dyslipidemia, diabetes, or ≥ 2 of these risk factors suggested a BMI cutoff of 26 and a waist circumference cutoff of 90 cm for both men and women.

CONCLUSIONS

Higher cutoffs for BMI and waist circumference are needed in the identification of Uighur patients at high risk of cardiovascular disease.

Appropriate body mass index and waist circumference cutoff for overweight and central obesity among adults in Cambodia

BACKGROUND

Body mass index (BMI) and waist circumference (WC) are used in risk assessment for the development of non-communicable diseases (NCDs) worldwide. Within a Cambodian population, this study aimed to identify an appropriate BMI and WC cutoff to capture those individuals that are overweight and have an elevated risk of vascular disease.

METHODOLOGY/PRINCIPAL FINDINGS

We used nationally representative cross-sectional data from the STEP survey conducted by the Department of Preventive Medicine, Ministry of Health, Cambodia in 2010. In total, 5,015 subjects between age 25 and 64 years were included in the analyses. Chi-square, Fisher's Exact test and Student t-test, and multiple logistic regression were performed. Of total, 35.6% (n = 1,786) were men, and 64.4% (n = 3,229) were women. Mean age was 43.0 years (SD = 11.2 years) and 43.6 years (SD = 10.9 years) for men and women, respectively. Significant association of subjects with hypertension and hypercholesterolemia was found in those with BMI ≥ 23.0 kg/m(2) and with WC >80.0 cm in both sexes. The Area Under the Curve (AUC) from Receiver Operating Characteristic curves was significantly greater in both sexes (all p-values <0.001) when BMI of 23.0 kg/m(2) was used as the cutoff point for overweight compared to that using WHO BMI classification for overweight (BMI ≥ 25.0 kg/m(2)) for detecting the three cardiovascular risk factors. Similarly, AUC was also significantly higher in men (p-value <0.001) when using WC of 80.0 cm as the cutoff point for central obesity compared to that recommended by WHO (WC ≥ 94.0 cm in men).

CONCLUSION

Lower cutoffs for BMI and WC should be used to identify of risks of hypertension, diabetes, and hypercholesterolemia for Cambodian aged between 25 and 64 years.

Quantification of visceral adipose tissue using lunar dual-energy X-ray absorptiometry in Asian Chinese

OBJECTIVE

To evaluate the new DXA VAT method on an Asian Chinese population by comparing to a reference method, computed tomography (CT).

DESIGN AND METHODS

In total, 145 adult men and women volunteers, representing a wide range of ages (19-83 years) and BMI values (18.5-39.3 kg/m(2) ) were studied with both DXA and CT.

RESULTS

The coefficient of determination (r(2) ) for regression of CT on DXA values was 0.947 for females, 0.891 for males and 0.915 combined. The 95% confidence interval for r was 0.940-0.969 for the combined data. The Bland-Altman test showed a VAT bias (CT as standard method) of 143 cm(3) for females and 379 cm(3) for males. Combined, the bias was 262 cm(3) with 95% limits of agreement of -232 to 755 cm(3) . While the current DXA method moderately overestimates the VAT volume for the study subjects, a further analysis suggested that the overestimation could be largely contributed to VAT movement due to breath-holding status.

CONCLUSIONS

For Asian Chinese, VAT measured with DXA is highly correlated to VAT measured with CT. Validation of the DXA VAT tool using a reference method (e.g., CT) needs to carefully control the breath-holding protocol.

Measurement of Waist Circumference: midabdominal or iliac crest?

OBJECTIVE

Waist circumference (WC) is used to define central obesity. This study aimed to compare the performance of two recommended locations of WC measurement.

RESEARCH DESIGN AND METHODS

A cohort of 1,898 subjects who were without diabetes from 2006 to 2012 were followed for a median of 31 months (Taiwan Lifestyle Study). The WC-IC, recommended by the National Cholesterol Education Program Third Adult Treatment Panel, was measured at the superior border of the iliac crest, and the WC-mid, recommended by World Health Organization and International Diabetes Federation, was measured midway between the lowest ribs and the iliac crest. The abdominal subcutaneous fat area (SFA) and visceral fat area (VFA) were assessed by computed tomography.

RESULTS

There was greater difference between WC-IC and WC-mid measurements in women than in men (P < 0.001). Both WC-IC and WC-mid correlated significantly with BMI, VFA, and SFA (all P < 0.001). WC-mid was better correlated to VFA than WC-IC, particularly in women, and it correlated more strongly to blood pressure, plasma glucose, hemoglobin A1c, triglyceride levels, HDL cholesterol, and C-reactive protein (all P < 0.05). The association of WC-mid with hypertension, diabetes, and metabolic syndrome was slightly better than that of WC-IC (area under the receiver operator curve 0.7 vs. 0.69, 0.71 vs. 0.68, and 0.75 vs. 0.7, respectively; all age-adjusted P < 0.05). With 90 cm (male)/80 cm (female) as criteria for central obesity, WC-mid, but not WC-IC, predicted the incidence of diabetes development (age-adjusted P = 0.003).

CONCLUSIONS

WC-mid is a better measurement to define central obesity than WC-IC, particularly in women.

Increasing trends in central obesity among Chinese adults with normal body mass index, 1993-2009

Background

Central obesity is thought to be more pathogenic than overall obesity and studies have shown that the association between waist circumference (WC) and mortality was strongest in those with a normal body mass index (BMI). The objective of our study was to determine secular trends in the prevalence of central obesity (WC ≥ 90 cm for men and ≥ 80 cm for women) among Chinese adults with normal BMI from 1993 to 2009 and to examine the impact of performance of combined BMI and WC on the prevalence of obesity in Chinese adults.

Methods

We used data from the China Health and Nutrition Survey (CHNS) conducted from 1993 to 2009. From which we included a total of 52023 participants aged ≥ 18 years.

Results

The age-standardized prevalence of central obesity among Chinese adults with BMI < 25 kg/m² increased from 11.9% in 1993 to 21.1% in 2009 (P for linear trend <0.001). The upward trends were noted in both genders, all ages, rural/urban settings, and education groups (all P for linear trend <0.001), with greater increments in men, participants aged 18–64 years, and rural residents (P for interaction terms survey × sex, survey × age, and survey × rural/urban settings were 0.042, 0.003, and < 0.001, respectively). Trends in the prevalence of central obesity were similar when a more stringent BMI < 23 kg/m² cut point (Asian cut point) was applied. Central obesity is associated with a higher risk of incident hypertension within normal BMI category. More than 65% individuals with obesity would be missed if solely BMI was measured.

Conclusions

We observed an upward trend in the prevalence of central obesity among participants with normal BMI irrespective of sex, age, rural/urban settings, and education level. Central obesity is associated with a higher risk of incident hypertension within normal BMI category. Approximately two thirds of the individuals with obesity would be missed if WC was not measured. It is, therefore, urgent to emphasize the importance of WC as a measure to monitor the prevalence of obesity.

BMI and Metabolic Disorders in South Korean Adults: 1998 Korea National Health and Nutrition Survey

OBJECTIVE

The prevalence of overweight, obesity, and metabolic disorders and their relationship with BMI were studied in South Korean adults. The appropriate BMI categories for overweight and obesity for Koreans were evaluated.

RESEARCH METHODS AND PROCEDURES

The 1998 Korea National Health and Nutrition Examination Survey was the first such survey, to our knowledge, conducted on a cross-sectional and nationally representative population. The survey provided data on body weight; height; fasting serum glucose; triacylglycerol; total, low-density lipoprotein, and high-density lipoprotein cholesterol; blood pressure; and various other questions that were incorporated into this study. A total of 39,060 persons over the age of 1 year from 12,283 households participated in the Health and Nutrition Interview Survey. Of these, 10,876 people over the age of 10 years old participated in the Health Examination. We analyzed data from 7962 adults over the age of 20 years old.

RESULTS

The overweight (BMI, >/=25.0 to <30.0) and obesity (BMI, >/=30) rates were low among Korean adults: 23.4% and 1.7% in men and 24.9% and 3.2% in women, respectively. However, the prevalences of diabetes, hypertension, and abnormal concentrations of serum triacylglycerol and total, low-density lipoprotein, and high-density lipoprotein cholesterol were high at 10.5%, 27.1%, 29.0%, 34.5%, 28.4%, and 37.4%, respectively. These disorders were age dependent, and, in general, there was a strong linear relationship between BMI and the disorders. The relative risk of disorders doubled at a BMI of 23.0 to 24.0 and tripled at a BMI of 26.0, compared with a baseline BMI of 18.5 to 22.0.

DISCUSSION

High rates of diabetes, hypertension, and dyslipidemia were noted in middle-aged and elderly Koreans even at relatively low BMI. It might be appropriate to lower the BMI classification from the current >/=25.0 for overweight and >/=30.0 for obesity for this group of Koreans.

Influence of underweight on asthma control

BACKGROUND

Although the association between asthma control and body mass index (BMI) has been thoroughly investigated, most of this work has focused on the influence on asthma incidence or the effect of obesity on asthma control. To date, there have been no published studies on the influence of underweight on asthma control.

METHODS

The aim of this study was to investigate the influence of underweight, as defined by the Japan Society for the Study of Obesity (JASSO), on asthma control in Japanese asthmatic patients. Using data from questionnaire surveys administered by the Niigata Asthma Treatment Study Group, we compared asthma control, as measured by the Asthma Control Test (ACT), between a normal weight group (18.5kg/m2 =< BMI < 25kg/m2) and an underweight group (BMI < 18.5kg/m2).

RESULTS

Of the asthmatic patients who completed the 2008 and 2010 surveys, 1464 and 1260 cases were classified as being in the normal weight group, and 174 and 155 cases were classified as being in the underweight group. The ACT score (median, [interquartile range]) in the underweight group in 2008 (22, [19-24]) and 2010 (23, [19-25]) was significantly lower than that in the normal group in 2008 (23, [20-25]) and in 2010 (24, [21-25]).

CONCLUSIONS

This study is the first, large-scale investigation of the influence of underweight on asthma control, and we have confirmed an adverse influence in a clinical setting. A potential mechanism for this interaction was unknown. Further investigation will be required.

Anthropometric measures and lipid coronary heart disease risk factors in Korean immigrants with type 2 diabetes

OBJECTIVES

The purposes of this study were to (1) describe anthropometric measures among Korean immigrants with type 2 diabetes mellitus (T2DM) and (2) examine the relationships between measures of obesity with several forms of dyslipidemia in this group.

BACKGROUND

Obesity and dyslipidemia are commonly associated with T2DM, and they are risk factors for coronary heart disease (CHD), the leading cause of death for people with diabetes. Asians are predisposed to abdominal obesity and experience significant CHD risk at lower body mass index (BMI) levels. Despite high prevalence of diabetes among Korean immigrants, relationships among anthropometric measures and lipid-related CHD risk factors have not been examined.

METHODS

A convenience sample of 143 adult Korean immigrants with T2DM between the ages of 30 and 80 years participated in the study. Body mass index, waist circumference (WC), and waist-to-hip ratio (WHR) were obtained using standardized procedures. Total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were assessed using a fingerstick blood test. Hierarchical linear regressions were conducted to identify which of the anthropometric measures was significantly related to individuals' cholesterol levels.

RESULTS

Central obesity measures, not BMI, were significantly associated with dyslipidemia in Korean immigrants with T2DM independent of potential confounds such as hemoglobin A1C, cigarette smoking, age, and cholesterol medication. Different central obesity measures were associated with different cholesterol types for diabetic Korean men and women. In men, WHR was positively associated with low-density lipoprotein cholesterol and total cholesterol levels. In women, WC was negatively associated with high-density lipoprotein cholesterol.

CONCLUSIONS

Central obesity measures (WC and WHR) are better indicators for assessing lipid-related CHD risk factor among Korean immigrants with T2DM than BMI. Gender difference in the association between central obesity measures and lipid types should be considered in CHD risk assessment of Korean immigrants with T2DM.

Optimal cut-off levels of body mass index and waist circumference in relation to each component of metabolic syndrome (MetS) and the number of MetS component

AIMS

There is an ethnic difference of obesity index to diagnose metabolic syndrome. The authors explored the optimal cut-off levels for body mass index (BMI) and waist circumference (WC) in relation to each component of metabolic syndrome.

MATERIALS AND METHODS

Receiver operating characteristics (ROC) analysis was used to determine the optimal cut-off levels for each component of metabolic syndrome. This study included 4572 workers aged 42.5±9.9 years.

RESULTS

The optimal BMI cut-off values for diabetes mellitus, hypertension or dyslipidemia varied from 23.0 to 24.3 kg/m(2). As for WC, the optimal cut-off values varied from 83.0 to 83.7 cm. The optimal BMI cut-off values relating with one to three components of metabolic syndrome varied from 23.2 to 25.3 kg/m(2). As for WC, the optimal cut-off values varied from 83.0 to 85.0 cm. Pair-wise comparison of ROC curves showed that WC has an advantage in relation to metabolic syndrome and its components compared with BMI. By logistic regression analysis, odds ratios of obesity indices for hypertension, dyslipidemia or the number of metabolic component were all significantly increased. As for diabetes mellitus, odds ratios of BMI ≥25 and WC ≥85 significantly increased, respectively.

CONCLUSIONS

Japanese criteria of obesity in metabolic syndrome in man may be appropriate for diabetes mellitus. Ethnic difference in criteria of obesity in Asian metabolic syndrome exists, and mutual comparisons in the prevalence of metabolic syndrome have a difficulty to conduct.

Influence of obesity on control in asthmatic Japanese patients defined by the Japanese definition of obesity

BACKGROUND Despite the use of inhaled corticosteroid (ICS) becoming increasingly widespread, many problems related to asthma management still need to be addressed. One of them, obesity, has been reported to exert a harmful influence on asthma control. However, there have been few reports focusing not only on both obesity and its influence on Japanese asthma patients but also on the Japanese definition of obesity, as defined by the Japan Society for the Study of Obesity (JASSO). AIMS & METHODS The aim of this study was to confirm the influence of obesity, as defined by the JASSO, on asthma management in Japanese asthmatic patients. Using data from the Niigata Asthma Treatment Study Group 2008 questionnaire survey, differences between the "normal" group (18.5 kg/m(2) ≤ BMI <25 kg/m(2)) and the "obese" group (25 kg/m(2) ≤ BMI) were analyzed. RESULTS There was a significantly lower step 1 rate (19.4% v.s. 26.8%) and a higher proportion of patients using inhaled salmeterol (43.6% v.s. 35.8%) and leukotriene receptor antagonist (49.8% v.s. 40.8%) in the obese group relative to the normal group, although there were no significant differences in indicators of asthma control, including asthma control test scores. CONCLUSION This study investigated influences of JASSO-defined obesity on asthma severity and management in a clinical setting in Japan. It is possible that there are strong interactions between asthma and obesity, such as obesity causing decreased ICS therapy efficacy and leukotriene (LT)-related inflammation, although further investigation is necessary.

Gastroesophageal reflux disease in Asia: A historical perspective and present challenges

Gastroesophageal reflux disease (GERD), previously uncommon in Asia, has now become an important disease in the region. Although much variability exists between studies, most endoscopy-based studies show a prevalence of erosive esophagitis of more than 10%. Symptom-based studies also show a prevalence of 6-10%. Two longitudinal follow-up studies on GERD symptoms have shown an increase with time, and several endoscopy-based time trend studies have also shown a significant increase in erosive reflux esophagitis. Studies on Barrett's esophagus have been confounded by the description of short (SSBE) and long segment (LSBE) Barrett's esophagus. Great variation in prevalence rates has been reported. SSBE vary from 0.1% to more than 20% while LSBE vary from 1-2%. Of the putative causative factors, obesity has been the most important. Many studies have linked GERD-esophagitis as well as occurrence of reflux symptoms with an increase in body mass index (BMI), obesity, especially visceral or central obesity, and metabolic syndrome. A decline in Helicobacter pylori infection with growing affluence in Asia has been broadly thought to result in healthier stomachs and a higher gastric acid output resulting in reflux disease. However, variable results have been obtained from association and H. pylori eradication studies.

Body-mass index and cancer mortality in the Asia-Pacific Cohort Studies Collaboration: pooled analyses of 424,519 participants

BACKGROUND

Excess bodyweight is an established risk factor for several types of cancer, but there are sparse data from Asian populations, where the proportion of overweight and obese individuals is increasing rapidly and adiposity can be substantially greater for the same body-mass index (BMI) compared with people from Western populations.

METHODS

We examined associations of adult BMI with cancer mortality (overall and for 20 cancer sites) in geographic populations from Asia and from Australia and New Zealand (ANZ), within the Asia-Pacific Cohort Studies Collaboration, by use of Cox regression analysis. Pooled data from 39 cohorts (recruitment 1961-99, median follow-up 4 years) were analysed for 424,519 participants (77% Asian; 41% female; mean recruitment age 48 years) with individual data on BMI.

FINDINGS

After excluding those with follow-up of less than 3 years, 4872 cancer deaths occurred in 401,215 participants. Hazard ratios for cancer sites with increased mortality risk in obese (BMI > or = 30 kg/m(2)) compared with normal weight participants (BMI 18.5-24.9 kg/m(2)) were: 1.21 (95% CI 1.09-1.36) for all-cause cancer (excluding lung and upper aerodigestive tract), 1.50 (1.13-1.99) for colon, 1.68 (1.06-2.67) for rectum, 1.63 (1.13-2.35) for breast in women 60 years or older, 2.62 (1.57-4.37) for ovary, 4.21 (1.89-9.39) for cervix, 1.45 (0.97-2.19) for prostate, and 1.66 (1.03-2.68) for leukaemia (all after left censoring at 3 years). The increased risk associated with a 5-unit increase in BMI for those with BMI of 18.5 kg/m(2) or higher was 1.09 (95% CI 1.04-1.14) for all cancers (excluding lung and upper aerodigestive tract). There was little evidence of regional differences in relative risk of cancer with higher BMI, apart from cancers of the oropharynx and larynx, where the association was inverse in ANZ and absent in Asia.

INTERPRETATION

Overweight and obese individuals in populations across the Asia-Pacific region have a significantly increased risk of mortality from cancer. Strategies to prevent individuals from becoming overweight and obese in Asia are needed to reduce the burden of cancer that is expected if the obesity epidemic continues.

FUNDING

National Health and Medical Research Council of Australia, Health Research Council of New Zealand, and Pfizer Inc.