Secular trends in the prevalence of general and abdominal obesity among Chinese adults, 1993-2009

The objective of this study is to examine the trends in body mass index (BMI), waist circumference (WC) and prevalence of overweight (BMI 25-27.49 kg m(-2) ), general obesity (BMI ≥ 27.5 kg m(-2) ) and abdominal obesity (WC ≥ 90 cm for men and ≥80 cm for women) among Chinese adults from 1993 to 2009. Data were obtained from the China Health and Nutrition Survey, which was conducted from 1993 to 2009 and included a total of 52,621 Chinese adults. During the period of 1993-2009, mean BMI values increased by 1.6 kg m(-2) among men and 0.8 kg m(-2) among women; mean WC values increased by 7.0 cm among men and 4.7 cm among women. The prevalence of overweight increased from 8.0 to 17.1% among men (P < 0.001) and from 10.7 to 14.4% among women (P < 0.001); the prevalence of general obesity increased from 2.9 to 11.4% among men (P < 0.001) and from 5.0 to 10.1% among women (P < 0.001); the prevalence of abdominal obesity increased from 8.5 to 27.8% among men (P < 0.001) and from 27.8 to 45.9% among women (P < 0.001). Similar significant trends were observed in nearly all age groups and regions for both men and women. The prevalence of overweight, general obesity and abdominal obesity among Chinese adults has increased greatly during the past 17 years.     

Prevalence of abdominal obesity in adolescents: a systematic review

The objectives of this study were to (i) review extant literature on the prevalence of abdominal obesity (AO) in adolescents of both sex (10–19 years old); (ii) analyse the cut‐off points used for the diagnosis of AO and (iii) compare its prevalence between developed and developing countries. The search was carried out using online databases (MEDLINE, Web of Science, EMBASE, SPORTDiscus, SCIELO and BioMed Central), references cited by retrieved articles and by contact with the authors, considering articles published from the establishment of the databanks until 19 October 2009. Only original articles and those using waist circumference in the diagnosis were considered. Twenty‐nine studies met the inclusion criteria. Fourteen of these studies were performed in developed countries. The prevalence of AO varied from 3.8% to 51.7% in adolescents from developing countries. The range of results was smaller among developed countries; with values from 8.7% to 33.2%. Eighteen different cut‐off points were used. It was concluded the AO prevalence is high among adolescents, but is not clear what sex has a higher proportion and it is greater in adolescents from developing countries; however, there is no consensus in the literature about the criteria to be used.     

高尿酸血症与腹型肥胖的关系

研究表明,高尿酸血症和腹型肥胖密切相关,但其机制尚不十分清楚.本文在对比血尿酸与腹型肥胖评估指标关系的基础上,探讨了腹型肥胖引起高尿酸血症的可能成因,对内脏脂肪的蓄积和多种脂肪因子的分泌在参与高尿酸血症形成中的地位和研究进展予以了特别关注,从而为阐明高尿酸血症与腹型肥胖的关系,有效防治高尿酸血症提供了科学依据.     

Prevalence of obesity, central obesity and the associated factors in urban population aged 20–70 years, in the north of Iran: a population-based study and regression approach

Obesity is an undesirable outcome of changing of lifestyle and behaviours. It is also reversible predisposing factor for the development of several debilitating diseases. This study was aimed to determine the prevalence rate of obesity, overweight, central obesity and their associated factors in the north of Iran. We conducted a population-based cross-sectional study with a sample of 1800 women and 1800 men with respective mean ages of 37.5 +/- 13.0 and 38.5 +/- 14.2 years of urban population aged 20-70 years living in the north of Iran. The demographic and lifestyle data, in particular, age, gender, marital status, marriage age, family history of obesity, educational level, occupation, occupational and leisure time physical activity, duration of exercise per week, parity and the number of children were collected with a designed questionnaire. Diagnosis of obesity and central obesity were confirmed by the WHO standard recommended method by determining of body mass index (BMI) and waist circumference (WC). Logistic regression model was used to estimate the adjusted odds ratio (OR) and its 95% confidence interval. Over half of the study subjects were at educational levels of high school or higher; 79.4% of population was married and 35.3% had a family history of parental obesity. The majority of subjects in particular women had none or low levels of physical activity. The overall prevalence rates of obesity and overweight were 18.8% and 34.8% respectively. The overall prevalence rate of central obesity was 28.3%. The rate of obesity in women was higher than men (P < 0.0001). In both genders, particularly in the women, the rate of obesity was raised by increasing age. There was an inverse relation between the risk of obesity and marriage age, the high level of education (OR = 0.19, P < 0.0001), severe occupational activity (OR = 0.44, P < 0.0001), the level of exercise (in subjects with 3-4 h exercise per week, OR = 0.58, P < 0.001) and leisure time activity. Marriage, history of parental obesity and parity > or =5 were associated with increased risk of obesity (OR = 2.2, P < 0.001 and OR = 2.43, P < 0.0001 and OR = 3.73, P < 0.0001 respectively). The results of this study indicate an increased rate of obesity and overweigh in the north population of Iran. With respect to these findings, low level of activity and education, parity, family history of obesity, marriage at earlier age and ageing are responsible for both obesity and central obesity in the north of Iran. Therefore, a community-based multiple strategies are required to combat with increasing rate of obesity and its subsequent complications such as diabetes, coronary artery disease, hypertension and osteoarthritis.     

Associations of breaks in sedentary time with abdominal obesity in Portuguese older adults

In older adults, sedentary time is positively associated with obesity. The manner in which it is accumulated, i.e., the number of breaks in sedentary time, might be also important. We examined the cross-sectional associations of breaks in sedentary time with abdominal obesity in 301 older adults (111 men and 190 women) aged 75.0 ± 6.8 years. Sedentary time (counts min⁻¹ < 100) and physical activity were objectively measured by accelerometry, worn during waking hours for at least three consecutive days. A break was defined as an interruption (≥100 counts min⁻¹ < 2020) in sedentary time while performing light intensity physical activities. Sedentary time was expressed as the number of daily breaks in sedentary time or hourly breaks in sedentary time. Abdominal obesity was defined by waist circumference (men >102 cm; women >88 cm). Using binary logistic regression analyses, the odds for abdominal obesity decreased 7 % for each additional hourly break in sedentary time in women (OR = 0.93, 95 % CI: 0.87–1.00), but not men, independently of total sedentary time and moderate-to-vigorous physical activity. The odds for abdominal obesity were 3.21 times higher (p = 0.039) for women in quartile 1 (<225 breaks day⁻¹) of daily breaks in sedentary time compared to those in quartile 4 (>353 breaks day⁻¹) of daily breaks in sedentary time.These findings indicate that older women who interrupt their sedentary time more frequently are less likely to present abdominal obesity. Public health recommendations regarding breaking-up sedentary time complementary to those for physical activity are likely to be relevant.     

Overweight and obesity in a representative sample of schoolchildren – exploring the urban–rural gradient in Sweden

To present the prevalence and urban‐rural differences of overweight and obesity in 7–9‐year‐old Swedish schoolchildren, we used anthropometric data from a nationally representative survey performed in 2008. Trained staff weighed and measured 4538 children in grades 1 and 2 in 94 primary schools. Weight classification was performed using the IOTF reference and school areas were classified based on level of urbanization and area‐level education. Overweight was found in 17% of the children including 3% obese. For overweight, odds‐ratios were 1.33 and 1.61 (significant) in semi‐urban and rural areas, relative to urban areas. After adjusting for area‐level education, differences by degree of urbanisation were greatly attenuated and non‐significant. For obesity urban‐rural differences were observed in boys only and remained after adjustment for area‐level education. For area‐level education, risk estimates were significantly elevated and unaffected by urbanization and gender, odds‐ratios 1.75 and 2.21 for overweight and 2.62 and 3.69 for obesity, in medium‐ and low‐education areas compared to high‐education areas. This supports earlier reports identifying areas with low socioeconomic status as high‐risk areas for overweight and obesity. However, this study also suggests that gender should be considered when targeting children in urban as well as rural communities for health promoting interventions.     

Central obesity and risks of pre‐ and postmenopausal breast cancer: a dose–response meta‐analysis of prospective studies

Epidemiologic evidence has shown inconsistent findings regarding the relationships between abdominal fatness, as measured by waist circumferences (WC) or waist‐to‐hip ratio (WHR), and risks of pre‐ and postmenopausal breast cancer (BC). A dose–response meta‐analysis of prospective studies was conducted to address these issues. Potentially eligible studies were identified by searching PubMed and EMBASE databases, and by carefully reviewing the bibliographies of retrieved publications and related reviews. The summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random‐effects model. When the most fully adjusted RRs were combined, both WC (14 studies, RR _{per 10‐cm increase} = 1.06, 95% CI: 1.04–1.09, I² = 29.9%) and WHR (15 studies, RR _{per 0.1‐unit increase} = 1.07, 95% CI: 1.01–1.14, I² = 52.9%) were significantly positively associated with postmenopausal BC, but neither WC (eight studies, RR _{per 10‐cm increase} = 1.05, 95% CI: 0.99–1.10, I² = 0%) nor WHR (11 studies, RR _{per 0.1‐unit increase} = 1.07, 95% CI: 0.95–1.21, I² = 59.7%) were associated with premenopausal BC. The WHR‐postmenopausal BC association lost statistical significance after correcting publication bias (RR _{per 0.1‐unit increase} = 1.06, 95% CI: 0.99–1.13). When considering BMI‐adjusted RRs, WC was associated with both pre‐ (five studies, RR _{per 10‐cm increase} = 1.09, 95% CI: 1.02–1.16, I² = 0%) and postmenopausal BC (seven studies, RR _{per 10‐cm increase} = 1.05, 95% CI: 1.02–1.08, I² = 6.3%), whereas WHR was not associated with either pre‐ (seven studies, RR _{per 0.1‐unit increase} = 1.12, 95% CI: 0.94–1.34, I² = 70.9%) or postmenopausal BC (eight studies, RR _{per 0.1‐unit increase} = 1.05, 95% CI: 0.98–1.13, I² = 57.3%). Among non‐current (former or never) users of hormone replacement therapy, the summary RR _{per 10‐cm increase} of postmenopausal BC associated with WC was 1.08 (95% CI: 1.03–1.05, I² = 69.2%, seven studies; BMI‐adjusted RR = 1.05, 95% CI: 1.02–1.09, I² = 22.8%, four studies). This meta‐analysis indicates that central obesity measured by WC, but not by WHR, is associated with modestly increased risks of both pre‐ and postmenopausal BC independent of general obesity.     

Trends in body mass index and waist circumference among New Zealand adolescents, 1997/1998–2005

The objective of the current study is to examine changes in body mass index (BMI) and waist circumference among New Zealand adolescents between 1997/1998 and 2005. Data were drawn from two cross-sectional studies of high school students in an economically disadvantaged region of Auckland. In total, 608 adolescents from the 1998 survey and 897 adolescents from the 2005 survey participated. The prevalence of obesity increased from 19.4% in 1997/1998 to 30.7% in 2005. The mean BMI among adolescents significantly increased from 25.3 in 1997/1998 to 27.2 in 2005, with the greatest increases at the high end of the distribution. Increases in BMI did not differ by age, gender or ethnicity. The mean waist circumference increased from 76.2 cm in 1997/1998 to 89.4 cm in 2005, with increases in waist circumference measurements at all points in the distribution. The prevalence of obesity is increasing rapidly in this sample of ethnically diverse adolescents. Corresponding increases in waist circumference measurements suggest that this population of New Zealand adolescents are at increased risk for related chronic conditions.     

Prevalence of general and abdominal obesity in the adult population of Spain, 2008-2010: the ENRICA study

This is the first study to report the prevalence of general obesity and abdominal obesity (AO) in the adult population of Spain based on measurements of weight, height and waist circumference. The data are taken from the ENRICA study, a cross‐sectional study carried out between June 2008 and October 2010 in 12,883 individuals representative of the non‐institutionalized population on Spain aged 18 years and older. Anthropometry was performed under standardized conditions in the households by trained interviewers. Overweight was considered as body mass index (BMI) 25–29.9 kg m^?2, and obesity as BMI ≥ 30 kg m^?2. AO was defined as waist circumference >102 cm in men and >88 cm in women. The prevalence of obesity was 22.9% (24.4% in men and 21.4% in women). About 36% of adults had AO (32% of men and 39% of women). The frequency of obesity and of AO increased with age and affected, respectively, 35 and 62% of persons aged 65 and over. The frequency of obesity and AO decreased with increasing educational level. For example, 29% of women with primary education or less had obesity vs. only 11% of those with university studies. The prevalence of obesity was very high in the Canary Islands and in the south of Spain.     

Prevalence of obesity in Switzerland 1992–2007: the impact of education,income and occupational class

Prevalence of excess weight varies substantially by socioeconomic position (SEP). SEP can be defined with different indicators. The strength of the association of SEP with excess weight differs by SEP indicator, between populations and over time. We examined the prevalence of overweight and obesity (body mass index 25–29.9 and ≥30 kg m^?2) in Switzerland by educational level, household income tertile and occupational class (three categories for each indicator). Self‐reported data stem from four cross‐sectional population surveys including 53 588 persons aged between 25 and 74 years. The overall prevalence of overweight increased between 1992 and 2007 from 37.4% to 41.4% in men and from 18.8% to 21.9% in women. Obesity prevalence increased from 7.2% to 9.7% in men and from 5.4% to 8.6% in women. Inequalities were calculated with multivariable logistic regression. Inequalities were larger in women than in men and for obesity than for overweight. However, overweight and obesity inequalities did not significantly change over time, despite overall increasing prevalence. Although all SEP indicators were independently associated with excess weight, the association was strongest with education, particularly in women. Programmes and policies aimed at preventing excess weight should target individuals with low education early in life.     

Association between senescence-related uncoupling protein 2 gene polymorphisms and abdominal obesity in Japanese subjects: The Tanno and Sobetsu study

Background:   Uncoupling protein 2 ( UCP2 ) plays an important role in regulating body weight, energy expenditure and insulin secretion. UCP2 is upregulated in white fat in response to fat feeding, and negatively controls insulin secretion. UCP2 also has a function that protects cells from apoptosis and oxidative stress, which shows UCP2 might be a senescence-related gene. Previously, UCP2 -866G/A polymorphism in the promoter region has been reported to alter adipose tissue mRNA expression and is associated with obesity in Caucasians.
Methods:   In this study, we investigated the association between this polymorphism and obesity, insulin secretion and hypertension in the general Japanese population.
Results:   The allele frequency of UCP2 -866G/A polymorphism was significantly higher in Japanese subjects compared to Caucasians. It revealed that subjects only in the obese group with the AA type of UCP2 -866G/A polymorphism had significantly higher levels of body mass index (BMI) and waist circumference. Multiple logistic regression analysis showed that this polymorphism was independently associated with waist circumference. This positive association remained in the analysis of the subgroup younger than 65 years, but not in the older group. This polymorphism did not affect levels of insulin and homeostasis model assessment ratio (HOMA-R).
Conclusions:   These results suggest that the AA type of UCP2 -866G/A polymorphism is related to abdominal obesity, which indicates the possible role of this polymorphism in causing metabolic syndromes.     

Percentile distributions of waist circumference for 7–19‐year‐old Polish children and adolescents

The aim of the study was to develop waist circumference (WC) percentiles in Polish children and youth and to compare these with the results obtained in other countries. The study comprised a random group of 5663 Polish children aged 7–18 years. Smoothed WC percentile curves were computed using the LMS method. The curves displaying the values of the 50th (WC₅₀) and the 90th (WC₉₀) percentile were then compared with the results of similar studies carried out in children from the UK, Spain, Germany, Turkey, Cyprus, Canada and the USA. WC increased with age in both boys and girls and in all observed age periods the boys were seen to dominate. For 18‐year‐old Polish boys and girls the values of WC₉₀ were 86.5 and 78.2, respectively, and were lower than the current criteria developed by the International Diabetes Federation. Both WC₅₀ and WC₉₀ were higher in Polish boys and girls compared with their counterparts in the UK, Turkey and Canada and significantly lower than in children from the USA, Cyprus and Spain. The percentile curves for Polish children and youth, which were developed here for the first time, are base curves that can be applied in analysing trends as well as making comparisons with results of similar studies performed in other countries.     

Fatty and lean red meat consumption in China: Differential association with Chinese abdominal obesity

AimWe examined the longitudinal association between red meat (RM) consumption and the risk of abdominal obesity in Chinese adults.Methods and resultsOur data are from 16,822 adults aged 18–75 in the China Health and Nutrition Survey from 1993 to 2011. We assessed RM intake with three 24-h dietary recalls. We defined abdominal obesity as a waist circumference (WC) ≥85 centimeters (cm) for men and ≥80 cm for women. Multilevel mixed-effect regression models showed that men experienced WC increases of 0.74 cm (95% confidence interval [CI]: 0.39–1.09) from a higher total intake of fresh RM and 0.59 cm (95% CI: 0.24–0. 95) from a higher intake of fatty fresh RM but 0.14 cm (95% CI: −0.39 to 0.66) from a higher intake of lean fresh RM in the top quartile versus non-consumers when adjusted for potential confounders. In contrast, after additional adjustment for baseline WC, the odds ratios of abdominal obesity in men were attenuated for total fresh RM (1.25 [95% CI: 1.06–1.47]) and fatty fresh RM (1.22 [95% CI: 1.03–1.44]) but were still not affected by lean fresh RM (0.95 [95% CI: 0.75–1.22]). Women also showed a positive association of fatty fresh RM intake with abdominal obesity.ConclusionGreater intake of fatty fresh RM was significantly associated with higher WC (men only) and abdominal obesity risk in Chinese adults. The gender-specific differential association of fatty versus lean fresh RM warrants further study.     

Body fat percentage,obesity, and their relation to the incidental risk of hypertension

Studies have indicated that increased body fat is associated with cardiovascular risk factors including hypertension. However, there is only limited information about the influence of body fat percentage (BF%) on incident hypertension. In a cohort of Korean genome epidemiology study (KoGES), 4864 non‐hypertensive participants were divided into 5 quintile groups, and followed‐up for 10 years to monitor incident hypertension. Cox proportional hazard model was used to evaluate the hazard ratio (HRs) and 95% confidence interval (CI) for hypertension (adjusted HRs [95% CI]) according to BF% quintile groups. Subgroup analysis was conducted by low or high level of BF% (cutoff: 22.5% in men and 32.5% in women) and low or high level of body mass index (BMI), waist circumference (WC) and waist‐to‐hip ratio (WHR). In adjusted model, compared with BF% quintile 1, the risk of incident hypertension significantly increased over BF% quintile 3 (BF% ≥19.9%) in men (quintile 3:1.42 [1.10‐1.85], quintile 4:1.58 [1.22‐2.05], quintile 5:1.82 [1.40‐2.36]), and quintile 4 (BF% ≥32.5%) in women (quintile 4:1.48 [1.12‐1.94], quintile 5:1.56 [1.20‐2.04]). Subgroup analysis showed that individuals with high BF% were significantly associated with the increased risk of hypertension even in individuals with low BMI, WC, and WHR. The risk of hypertension increased proportionally to BF% over the specific level of BF% in Koreans. Even in non‐obese individuals, increase in BF% was significantly associated with the increased risk of hypertension.     

Discordances in the application of different criteria for quantification of paediatric abdominal obesity: an analysis of two Swiss studies

Several definitions of paediatric abdominal obesity have been proposed but it is unclear whether they lead to similar results. We assessed the prevalence of abdominal obesity using five different waist circumference-based definitions and their agreement with total body fat (TBF) and abdominal fat (AF). Data from 190 girls and 162 boys (Ballabeina), and from 134 girls and 113 boys (Kinder-Sportstudie, KISS) aged 5–11 years were used. TBF was assessed by bioimpedance (Ballabeina) or dual energy X-ray absorption (KISS). On the basis of the definition used, the prevalence of abdominal obesity varied between 3.1 and 49.4% in boys, and 4.7 and 55.5% in girls (Ballabeina), and between 1.8 and 36.3% in boys and 4.5 and 37.3% in girls (KISS). Among children considered as abdominally obese by at least one definition, 32.0 (Ballabeina) and 44.7% (KISS) were considered as such by at least two (out of five possible) definitions. Using excess TBF or AF as reference, the areas under the receiver operating curve varied between 0.577 and 0.762 (Ballabeina), and 0.583 and 0.818 (KISS). We conclude that current definitions of abdominal obesity in children lead to wide prevalence estimates and should not be used until a standard definition can be proposed.     

Combined associations of general obesity and central obesity with hypertension stages and phenotypes among children and adolescents in Zhejiang,China

General and central obesity are suggested to be associated with elevated blood pressure (BP), whereas few studies have investigated their combined associations with hypertension in children. This study aimed to assess the associations of combinations of general obesity and central obesity with hypertension in Chinese children, including its stages and phenotypes. A total of 5430 children aged 7–17 years in Zhejiang Province were enrolled. General obesity was evaluated by body mass index (BMI), while central obesity was by waist circumference (WC). Then all children were sorted into three mutually exclusive groups: normal weight with or with no central obesity (NW), abnormal weight with no central obesity (AWNCO), and abnormal weight with central obesity (AWCO). Hypertension was defined as either a systolic or diastolic BP ≥ 95th percentile, and further classified into stage 1 hypertension, stage 2 hypertension, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic diastolic hypertension (SDH). Logistic regression was used. AWNCO and AWCO were associated with stage 1 hypertension (AWNCO, odds ratio [OR] = 1.94, 95% confidence interval [CI]: 1.59-2.37; AWCO, 2.67, 2.20-3.25), stage 2 hypertension (AWNCO, 2.35, 1.33-4.13; AWCO, 4.53, 2.79-7.37), ISH (AWNCO, 2.50, 1.96-3.18; AWCO, 3.95, 3.15-4.95), and SDH (AWNCO, 2.48, 1.75-3.52; AWCO, 2.78, 1.94-3.99). Children with AWCO were more likely to have stage 1 and stage 2 hypertension, as well as ISH and SDH. The combined measurement of general and central obesity is suggested as an appropriate screening tool for hypertension among children and adolescents.