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

Association between body mass index and mortality in a prospective cohort of Chinese adults

Obesity is associated with an increased risk of diabetes mellitus, hypertension, and coronary artery disease; however, the relation between body mass index (BMI) and the risk of all-cause mortality is controversial. We prospectively examined the relationship between BMI and all-cause mortality in 123,384 Chinese men and women who participated in the Kailuan health examination study from 2006 to 2007 and 2008 to 2009. Cases included 6218 deaths (5770 men and 448 women) that occurred during a mean follow-up period of 7.39 years. Relative risk was adjusted for factors such as age, serum lipid levels (ie, triglyceride, high-density lipoprotein, and low-density lipoprotein cholesterol), history of smoking and drinking, and physical activity, as well as a medical history of hypertension, diabetes, myocardial infarction, and stroke. Within the cohort, the lowest risk of all-cause mortality was seen among persons with a BMI of 24 to 28 kg/m in male, and the risk was elevated among persons with BMI levels lower or higher than that range. Moreover, all-cause mortality was greatest in the group with a BMI of <18.5 kg/m. In contrast, in female, a high BMI was associated with increased mortality, and a BMI of <18.5 kg/m was associated with the lowest risk. Further, a U-shaped association was seen between BMI and the risk of death from any cause among men and women, even after adjusting for confounding factors. In conclusion, underweight was associated with a substantially increased risk of all-cause mortality in males. The excess risk of all-cause mortality with a high BMI, however, was seen among females.

Reduction in postpartum weight with laser acupuncture: A randomized control trial

BACKGROUND

Gestational weight gain and weight retention at 1 year after delivery are associated with long-term obesity. We aimed to investigate the effect of laser acupuncture therapy on postpartum weight control.

METHODS

We randomly assigned 66 subjects with postpartum weight retention to a laser acupuncture group and control group. The subjects were treated at acupoints including the stomach and hunger points of the ear, ST25, ST28, ST40, SP15, CV9, and SP6 by using verum or sham laser acupuncture over 5 sessions per week. After 12 treatment sessions, the differences in the body mass index (BMI), body fat percentage (BFP), and waist-to-buttocks ratio (WBR) of the patients were analyzed and compared between the laser acupuncture and control groups via analysis of variance, chi-square tests, and stepwise regression tests.

RESULTS

The characteristics of the patients did not significantly differ between the laser acupuncture and control groups. Analysis of repeated measures data between the laser acupuncture and control groups indicated the presence of significant differences in postpartum BMI (P < 0.001) and BFP (P < 0.001); however, no significant difference was observed for WBR (P = 0.09).

CONCLUSION

Laser acupuncture reduces postpartum weight retention by improving BMI and BFP, but does not impact the WBR following short-term treatment.

Are We in the Same Risk of Diabetes Mellitus? Gender- and Age-Specific Epidemiology of Diabetes in 2001 to 2014 in the Korean Population

In the early 2000s, the prevalence of diabetes in adults aged ≥30 years in Korea was about 9% to 10%, and it remained stable. However, a nationwide survey showed that this prevalence increased over the past few years. After age-standardization using the Korean population of the year 2010, the prevalence of diabetes in adults aged ≥30 years was 10.0% to 10.8% between 2001 and 2012, which increased to 12.5% in 2013 and 11.6% in 2014. During that period, there have been changes in the gender- and age-specific prevalence of diabetes in Korean adults. The prevalence of diabetes in the elderly population increased significantly, while this prevalence in young adults, especially in young women, did not change significantly. The contribution of each diabetic risk factor, such as obesity, β-cell dysfunction, sarcopenia, and socioeconomic status, in developing diabetes has also changed during that period in each gender and age group. For young women, obesity was the most important risk factor; by contrast, for elderly diabetic patients, sarcopenia was more important than obesity as a risk factor. Considering the economic burden of diabetes and its associated comorbidities, a public health policy targeting the major risk factors in each population might be more effective in preventing diabetes.

Gender difference in the association between food away-from-home consumption and body weight outcomes among Chinese adults

Objective

The present study aimed to explore the associations between food away-from-home (FAFH) consumption and body weight outcomes among Chinese adults.

Design

FAFH was defined as food prepared at restaurants and the percentage of energy from FAFH was calculated. Measured BMI and waist circumference (WC) were used as body weight outcomes. Quantile regression models for BMI and WC were performed separately by gender.

Setting

Information on demographic, socio-economic, diet and health parameters at individual, household and community levels was collected in twelve provinces of China.

Subjects

A cross-sectional sample of 7738 non-pregnant individuals aged 18–60 years from the China Health and Nutrition Survey 2011 was analysed.

Results

For males, quantile regression models showed that percentage of energy from FAFH was associated with an increase in BMI of 0·01, 0·01, 0·01, 0·02, 0·02 and 0·03 kg/m2 at the 5th, 25th, 50th, 75th, 90th and 95th quantile, and an increase in WC of 0·04, 0·06, 0·06, 0·04, 0·06, 0·05 and 0·07 cm at the 5th, 10th, 25th, 50th, 75th, 90th and 95th quantile. For females, percentage of energy from FAFH was associated with 0·01, 0·01, 0·01 and 0·02 kg/m2 increase in BMI at the 10th, 25th, 90th and 95th quantile, and with 0·05, 0·04, 0·03 and 0·03 cm increase in WC at the 5th, 10th, 25th and 75th quantile.

Conclusions

Our findings suggest that FAFH consumption is relatively more important for BMI and WC among males rather than females in China. Public health initiatives are needed to encourage Chinese adults to make healthy food choices when eating out.

Developmental Idealism, Body Weight and Shape, and Marriage Entry in Transitional China

New trends toward later and less marriage are emerging in post-reform China. Previous research has examined the changing individual-level socioeconomic and demographic characteristics shaping marriage entry in Chinese adults. Employing a cultural model known as developmental idealism (DI), this study argues that a new worldview specifying an ideal body type has become popular in the West and that this new worldview has been exported to China. This new part of the DI package is likely stratified by gender, has a stronger impact on women than on men, and has likely penetrated urban areas more than rural areas. Drawing on the 1991-2009 longitudinal data from the China Health and Nutrition Survey, this study employs discrete-time logit models to estimate the relationships between various body types and transition to first marriage in Chinese young adults 18-30 years old. Body weight status and body shape are measured by body mass index (BMI) and waist-to-hip ratio (WHR), respectively, and further divided into categories of underweight, normal, and obese. Regression results indicate that larger values of BMI and WHR were associated with delayed entry into first marriage in urban women, whereas being overweight or obese was associated with accelerated transition to first marriage in rural men. Not only were these associations statistically significant, but their strengths were substantively remarkable. Findings from this study suggest that both body weight and body shape have important implications for marital success, independent of individual-level socioeconomic and demographic characteristics, and contribute to evolving gender and rural-urban disparities, as China is undergoing a rapid nutrition transition.

City Level of Income and Urbanization and Availability of Food Stores and Food Service Places in China

Objective

The contribution of unhealthy dietary patterns to the epidemic of obesity has been well recognized. Differences in availability of foods may have an important influence on individual eating behaviors and health disparities. This study examined the availability of food stores and food service places by city characteristics on city level of income and urbanization.

Methods

The cross-sectional survey was comprised of two parts: (1) an on-site observation to measure availability of food stores and food service places in 12 cities of China; (2) an in-store survey to determine the presence of fresh/frozen vegetables or fruits in all food stores. Trained investigators walked all the streets/roads within study tracts to identify all the food outlets. An observational survey questionnaire was used in all food stores to determine the presence of fresh/frozen vegetables or fruits. Urbanization index was determined for each city using a principal components factor analysis. City level of income and urbanization and numbers of each type of food stores and food service places were examined using negative binomial regression models.

Results

Large-sized supermarkets and specialty retailers had higher number of fresh/frozen vegetables or fruits sold compared to small/medium-sized markets. High-income versus low-income, high urbanized versus low urbanized areas had significantly more large-sized supermarkets and fewer small/medium-sized markets. In terms of restaurants, high urbanized cities had more western fast food restaurants and no statistically significant difference in the relative availability of any type of restaurants was found between high- and low-income areas.

Conclusions

The findings suggested food environment disparities did exist in different cities of China.

Physical activity attenuates genetic effects on BMI: Results from a study of Chinese adult twins

OBJECTIVE

This study aimed to examine the gene-environment interaction of physical activity and body mass index (BMI) using the Chinese National Twin Registry (CNTR).

METHODS

A total of 19,308 same-sex adult twins from CNTR were included in the analysis. Twin zygosity was determined by self-reported questionnaire. Height and weight were measured using self-reported questionnaire. The vigorous physical activity was defined as greater or equal to five times a week of at least 30 min moderate- or high-intensity physical activity. A twin structural equation model was used to analyze the gene-environment interaction of vigorous exercise with BMI among 13,506 monozygotic twins and 5,802 dizygotic twins.

RESULTS

A structural equation model adjusting for age and sex found vigorous exercise significantly moderated the additive genetic effects (P < 0.001) and shared environmental effects (P < 0.001) on BMI. The genetic contributions to BMI were significantly lower for people who adopted a physically active lifestyle [h(2) = 40%, 95% confidence interval (CI): 35%-46%] than those who were relative sedentary (h(2) = 59%, 95% CI: 52%-66%). The observed gene-physical activity interaction was more pronounced in men than women.

CONCLUSIONS

Our results suggested that adopting a physically active lifestyle may help to reduce the genetic influence on BMI among the Chinese population.

Association between the change in body mass index from early adulthood to midlife and subsequent type 2 diabetes mellitus

OBJECTIVE

To clarify the quantitative relationship of body mass index (BMI) change from early adulthood to midlife with presence of type 2 diabetes mellitus (T2DM) after midlife.

METHODS

This study included 120,666 middle-aged and elderly, whose retrospectively self-reported body weight at 20 and 40 years and measured height were available. BMI at 20 and 40 years and BMI change in between were defined as early-adulthood BMI, midlife BMI, and early-adulthood BMI change.

RESULTS

The odds ratio (OR) for T2DM associated with an 1-unit increment of early-adulthood or midlife BMI was 1.08 (95% confidence interval (CI), 1.07-1.08) and 1.09 (95% CI, 1.09-1.10) respectively. In the cross-tabulation of both early-adulthood BMI and BMI change, the prevalence of T2DM increased across both variables. Compared with participants with normal early-adulthood weight and BMI increase/decrease ≤1, the OR (95% CI) for T2DM of participants with early-adulthood overweight/obesity and BMI increase ≥4 kg/m(2) was 3.49 (3.05-4.00). For participants with early-adulthood underweight and BMI increase/decrease ≤ 1, the OR (95% CI) was 0.85 (0.75-0.97). Subgroup analysis according to sex and age showed similar trends.

CONCLUSIONS

Early-adulthood BMI may influence T2DM prevalence after midlife independent of current BMI. T2DM prevalence after midlife was positively associated with early-adulthood weight gain and inversely related to early-adulthood weight loss, while early-adulthood weight loss could not completely negate the adverse effect of early-adulthood overweight/obesity on diabetes.

Incidence of type 2 diabetes and number of events attributable to abdominal obesity in China: A cohort study

BACKGROUND

The aim of the present study was to estimate the incidence of type 2 diabetes (T2D) and the number of diabetes events attributable to abdominal obesity in China.

METHODS

A cohort study was conducted in a sample of 24,996 Chinese adults aged 35-74 years, with 19.9% of subjects lost to follow-up. Waist circumference (WC) was measured at baseline in 1998 and 2000-01, and abdominal obesity was defined as WC ≥ 90 cm in men and ≥80 cm in women. Information on incident diabetes was collected during follow-up in 2007-08. We estimated the number of T2D events attributed to abdominal obesity using confounder-adjusted population-attributable risk, incidence of diabetes, and the population size of China in 2010.

RESULTS

After a mean follow-up of 8.0 years, the age-standardized incidence of T2D was 9.6 and 9.2 per 1000 person-years in men and women, respectively. Abdominal obesity accounted for 28.1% (95% confidence interval [CI] 14.8%, 40.5%) of incident diabetes among men and 41.2% (95% CI 28.3%, 52.6%) among women using the diagnostic criteria of abdominal obesity recommended by the International Diabetes Federation. We estimated that, in 2010, 2.4 (95% CI 1.5, 3.2) million diabetes events were attributable to abdominal obesity: 1.0 (95% CI 0.5, 1.4) million in men and 1.4 (95% CI 1.0, 1.8) million in women.

CONCLUSIONS

Abdominal obesity is a major risk factor for T2D. Strengthening programs and initiatives for preventing and controlling obesity focusing on lifestyle changes should be a priority in the national strategy to reduce diabetes burden in China.

Prevalence of electrolyte and nutritional deficiencies in Chinese bariatric surgery candidates

BACKGROUND

Electrolyte and nutritional deficiencies have been reported in Western populations seeking bariatric surgery. However, data are scarce for Chinese patients.

OBJECTIVES

To investigate the prevalence of electrolyte and nutritional deficiencies in Chinese bariatric surgery candidates and to explore their associations with patients' demographic data.

SETTING

University hospital, China.

METHODS

Demographical data of 211 patients presenting for bariatric surgery were collected on gender, age, body mass index (BMI) and waist circumference (WC). Blood biochemical data were collected on some nutrients (hemoglobin, albumin, globulin, folate, vitamin B12, calcium, phosphorus, iron, ferritin, magnesium, parathyroid hormone [PTH], and vitamin D) and some electrolytes (potassium, sodium, and chloride).

RESULTS

Deficiencies were found for hemoglobin (2.8%), albumin (11.8%), globulin (1.4%), folate (32.2%), vitamin B12 (4.7%), corrected calcium (13.7%), phosphorus (10.4%), iron (9.0%), ferritin (1.9%), vitamin D (80.0%), potassium (5.7%), sodium (7.6%), and chloride (15.6%). Secondary hyperparathyroidism was found in 17.3%; no hypomagnesemia was encountered. A significant correlation was observed between age and folate, corrected calcium and PTH levels (r = .257, -.206, and .273, respectively; P<.05). Greater BMI was associated with lower albumin and folate (r = -.338 and -.370, respectively) and with higher globulin and phosphorus levels (r = .267 and .138, respectively). Folate deficiency was more common in the 18- to 30-year-old age group (P = .042) and the patients with BMI>45 kg/m(2) (P = .001). WC had an association with rates of albumin, folate, and corrected calcium deficiencies, as well as hemoglobin, albumin, and globulin, folate, phosphorus, and ferritin levels.

CONCLUSION

Electrolyte and nutritional deficiencies are common in Chinese bariatric surgery candidates. Routine evaluation of electrolyte and nutritional levels should be carried out in this population.

Changes in abdominal obesity in Chilean university students stratified by body mass index

Background

Studies based on Body Mass Index (BMI) and waist circumference (WC) are generally used to examine the prevalence and tendency of overweight and obesity. These studies help determine the socioeconomic development of a country and improve public health policies. Therefore, the goal of this research was to determine the trend of change in abdominal obesity of Chilean university students according to the Body Mass Index (BMI) measured in intervals of three and six years.

Methods

For this study, a total of 1598 students of both sexes ranging in age from 18 to 26 from a Chilean university were evaluated. Students were assessed commencing in 2007 (372 males and 315 females), 2010 (250 males and 330 females), and ending in 2013 (153 males and 178 females). During the three transversal assessments, weight, height, and waist circumference were evaluated. BMI was calculated for both sexes.

Results

No significant differences were found in age and BMI during the three years evaluated (2007, 2010, and 2013). In 2013, waist circumference (WC) increased significantly (p < 0.001 for both sexes). Moreover, in 2013, in all the percentiles evaluated, high values of WC were compared in relation to previous years. Furthermore, in 2013, in all four BMI categories (underweight, normal, overweight, and obese), the university students showed significant increases in WC (Females: p = 0.004; Males: p = 0.035) whereas in 2007 and 2010, the values remained relatively stable.

Conclusions

BMI remained constant during 2007, 2010, and 2013. However, the university students of both sexes showed greater risk of abdominal obesity as a result of increased WC in 2013.

Interactive Effects of Early Exclusive Breastfeeding and Pre-Pregnancy Maternal Weight Status on Young Children's BMI - A Chinese Birth Cohort

Objectives

To assess if the maternal pre-pregnancy weight status (MPWS) alters the association of early infant feeding pattern (at one and third months) with infant body mass index (BMI) in the first two years of life.

Methods

A cohort of 2,220 neonates were recruited in a community-based study conducted in China. Body weight and length were measured at birth, at age one and two, with BMI calculated accordingly. The BMI z-scores (BMI-Z) were computed according to the World Health Organization Growth Standard (2006). Feeding patterns were classified as exclusive breastfeeding (EBF), mixed feeding (MF), and formula feeding (FF). General linear models (GLM) were employed to estimate main and interaction effects of EBF and MPWS on children’s BMI-Z.

Results

No main effect of MPWS was found on child BMI-Z at ages one and two, nor the feeding patterns. An interaction between MPWS and feeding patterns was detected (p<0.05). For children who were formula fed during the first month, those who were born to overweight/obesity (OW/OB) mothers had a significantly greater BMI-Z at ages one and two, compared with those with underweight/normal weight (UW/NW) mothers. FF children had greater BMI-Z at ages one and two compared with their EBF and MF counterparts, when they were born to OW/OB mothers.

Conclusions

Maternal pre-pregnancy weight control and early initiation of EBF for children are essential for healthy development in children’s BMI, hence the prevention of early life obesity.

The impact of obesity towards prostate diseases

Evidence has supported obesity as a risk factor for both benign prostate hyperplasia (BPH) and prostate cancer (PCa). Obesity causes several mechanisms including increased intra-abdominal pressure, altered endocrine status, increased sympathetic nervous activity, increased inflammation process, and oxidative stress, all of which are favorable in the development of BPH. In PCa, there are several different mechanisms, such as decreased serum testosterone, peripheral aromatization of androgens, insulin resistance, and altered adipokine secretion caused by inflammation, which may precipitate the development of and even cause high-grade PCa. The role of obesity in prostatitis still remains unclear. A greater understanding of the pathogenesis of prostate disease and adiposity could allow the development of new therapeutic markers, prognostic indicators, and drug targets. This review was made to help better understanding of the association between central obesity and prostate diseases, such as prostatitis, BPH, and PCa.

The Ratio of Dietary Branched-Chain Amino Acids is Associated with a Lower Prevalence of Obesity in Young Northern Chinese Adults: An Internet-Based Cross-Sectional Study

This study aims to examine the association between the ratio of dietary branched chain amino acids (BCAA) and risk of obesity among young northern Chinese adults. A total of 948 randomly recruited participants were asked to finish our internet-based dietary questionnaire for the Chinese (IDQC). Associations between dietary BCAA ratio and prevalence of overweight/obesity and abdominal obesity were analyzed. Furthermore, 90 subjects were randomly selected to explore the possible mechanism. Dietary BCAA ratio in obese participants was significantly lower than non-obese participants. We found negative correlations between the ratio of dietary BCAA and body mass index (BMI) (r = -0.197, p < 0.001) or waist circumference (r = -0.187, p < 0.001). Compared with those in the first quartile, the multivariable-adjusted OR (95% CI) of the 3rd and 4th quartiles of dietary BCAA ratio for overweight/obesity were 0.508 (0.265-0.972) and 0.389 (0.193-0.783), respectively (all p < 0.05). After stratification by gender, the significance still existed in the 3rd and 4th quartile in males and the 4th quartile in females. For abdominal obesity, the multivariable-adjusted OR (95% CI) of the 3rd and 4th quartile of dietary BCAA ratio were 0.351 (0.145-0.845) and 0.376 (0.161-0.876), respectively (all p < 0.05). This significance was stronger in males. Further studies indicated that dietary BCAA ratio was inversely associated with 2-h postprandial glucose (2 h-PG) and status of inflammation. In conclusion, a higher ratio of dietary BCAA is inversely associated with prevalence of obesity, postprandial glucose and status of inflammation in young northern Chinese adults.

Prevalence and Secular Trends in Obesity Among Chinese Adults, 1991-2011

INTRODUCTION

The prevalence of obesity in Chinese adults increased from 1991 to 2000; however, recent changes in this trend are unclear. This study aims to estimate the current prevalence of obesity and to assess trends in obesity and BMI distribution in Chinese adults from 1991 through 2011.

METHODS

Height and weight measurements of 12,249 Chinese adults from the 2011 China Health and Nutrition Survey were analyzed (in 2013) together with China Health and Nutrition Survey data for 1991-2009. Obesity was defined as BMI≥28.0 kg/m(2) based on the Working Group on Obesity in China criteria.

RESULTS

In the 2011 survey, the age-adjusted mean BMI was 23.8 (95% CI=23.7, 23.9) for men and 23.4 (95% CI=23.2, 23.5) for women. The age-adjusted prevalence of obesity was 11.3% (95% CI=10.8%, 11.9%) overall, 11.8% (95% CI=10.8%, 12.6%) among men, and 11.0% (95% CI=10.3%, 11.8%) among women. Estimates of age-adjusted obesity prevalence among the Chinese population were significantly lower than those of the U.S. population (all p<0.05). Over the 20-year period, the prevalence of obesity increased from 2.88% to 11.8% among men (age-adjusted annual change in OR=1.08, 95% CI=1.07, 1.09, p<0.001) and from 4.55% to 11.0% among women (OR=1.05, 95% CI=1.05, 1.06, p<0.001). Similar significant findings were observed for both men and women based on WHO recommendations.

CONCLUSIONS

The prevalence of obesity among both Chinese men and women increased significantly from 1991 through 2011, particularly among men.

Metabolic syndrome and the risk of breast cancer among postmenopausal women in North-West China

OBJECTIVE

To determine whether metabolic syndrome (MetS) and its components are risk factors for breast cancer among postmenopausal women in China.

METHODS

Based on the baseline data of the Jinchang Cohort, a case-control study was carried out among postmenopausal women, including 43 cases and 86 controls. Both MetS and its components were evaluated. Odds ratios and 95% confidence intervals (CI) for the association were estimated by conditional logistic regression analysis.

RESULTS

The odds ratio of postmenopausal breast cancer was 3.505 (95% CI 1.282-9.583) for MetS, 3.016 (95% CI 1.044-8.715) for body mass index (BMI) ≥ 25 kg/m(2), and 3.191 (95% CI 1.253-8.125) for dyslipidemia. There was no significant association between postmenopausal breast cancer and hypertension as well as diabetes. Women with four metabolic factors showed greater risk for postmenopausal breast cancer (p(trend) < 0.05). Dyslipidemia and BMI ≥ 25 kg/m(2) showed most significant interaction on breast cancer (odds ratio = 11.359; 95% CI 2.663-48.450). With BMI ≥ 25 kg/m(2), the interaction of dyslipidemia and other metabolic factors on breast cancer was higher than that without BMI ≥ 25 kg/m(2).

CONCLUSION

This case-control study suggested that MetS was associated with an elevated risk of breast cancer among postmenopausal women in north-west China. Overweight and dyslipidemia had the strongest adverse effects on postmenopausal breast cancer.

Exercise intervention during pregnancy can be used to manage weight gain and improve pregnancy outcomes in women with gestational diabetes mellitus

Background

The study aimed to evaluate whether exercise intervention can be applied to pregnant women with gestational diabetes mellitus (GDM) for controlling gestational weight gain (GWG) and combating GDM-related outcomes.

Methods

Retrospective six months analysis of 14,168 single pregnant women without diabetes from 15 hospitals in Beijing in 2013. Each participant’s demographic data, interventions condition and medical information were collected individually by questionnaires and relying on medical records. The level of statistical significance was set equal to 0.05.

Results

2750 (19.4 %) pregnant women were diagnosed with GDM, 74.9 % of them received exercise intervention during pregnancy, and the starting time was 25.8 ± 3.7 gestational weeks. Women with GDM with exercise intervention (GDM-E) had the lowest BMI increase during late and mid-pregnancy than women with GDM without exercise intervention (GDM-nE) (2.05 ± 1.32 kg/m² vs. 2.40 ± 1.30 kg/m², p < 0.01) and non-GDM women (2.05 ± 1.32 kg/m² vs. 2.77 ± 1.21 kg/m², p < 0.01). Moreover, GDM-E group experienced a significantly lower risk of preterm birth (5.58 % vs. 7.98 %, p < 0.001), low birth weight (1.03 % vs. 2.06 %, p < 0.001) and macrosomia (9.51 % vs. 11.18 %, p > 0.05) than GDM-nE group. After including dietary factors in the analysis, women with GDM without either dietary or exercise intervention (GDM-nDnE) had the highest risk of preterm birth(OR = 1.64, 95 % CI, 1.14–2.36), while women with GDM with dietary intervention only (GDM-DnE) had the highest risk of low birth weight (OR = 3.10, 95 % CI, 1.23–7.81). However, women with GDM with both dietary and exercise intervention had the lowest rate of macrosomia.

Conclusion

Exercise intervention is a suitable non-invasive therapeutic option that can be readily applied to manage weight gain and improve pregnancy outcomes in women with GDM.

Major Dietary Patterns in Relation to General and Central Obesity among Chinese Adults

Limited evidence exists for the association between diet pattern and obesity phenotypes among Chinese adults. In the present study, we analyzed the cross-sectional data from 474,192 adults aged 30-79 years from the China Kadoorie Biobank baseline survey. Food consumption was collected by an interviewer-administered questionnaire. Three dietary patterns were extracted by factor analysis combined with cluster analysis. After being adjusted for potential confounders, individuals following a traditional southern dietary pattern had the lowest body mass index (BMI) and waist circumference (WC); the Western/new affluence dietary pattern had the highest BMI; and the traditional northern dietary pattern had the highest WC. Compared to the traditional southern dietary pattern in multivariable adjusted logistic models, individuals following a Western/new affluence dietary pattern had a significantly increased risk of general obesity (prevalence ratio (PR): 1.06, 95% confidence interval (CI): 1.03-1.08) and central obesity (PR: 1.07, 95% CI: 1.06-1.08). The corresponding risks for the traditional northern dietary pattern were 1.05 (1.02-1.09) and 1.17 (1.25-1.18), respectively. In addition, the associations were modified by lifestyle behaviors, and the combined effects with alcohol drinking, tobacco smoking, and physical activity were analyzed. Further prospective studies are needed to elucidate the diet-obesity relationships.

The Frequency of Unhealthy Food Advertising on Mainland Chinese Television (TV) and Children and Adolescents' Risk of Exposure to Them

OBJECTIVE

To conduct an analysis of the frequency of unhealthy food advertising on mainland Chinese television (TV) and children and adolescents' risk of exposure to them.

METHODS

The frequencies of all types of advertisements (ads) on forty TV channels in mainland China, the exact ad broadcast times, and the name and brand of all snacks and western fast foods advertised were recorded from 0800 hours to 2400 hours on both a weekday and a weekend day in a week. The difference in the frequencies of the diverse types of ads over eight time intervals (each time interval was 2 hours) were compared, and the trends in ad frequencies during the time intervals were described.

RESULTS

The TV channels broadcast 155 (91-183) (expressed as median [P25-P75]) food ads, 87 (38-123) snack ads, 49 (11-85) beverage ads, and 58 (25-76) ads of snacks suitable for limited consumption (SSLCs) in a day. The proportion of snack ads among food ads (SPF%) was 55.5% (40.3%-71.0%), and the proportion of SSLC ads among snack ads (LPS%) was 67.4% (55.4%-79.3%). The ad frequencies for food, snacks, SSLCs, and beverages demonstrated significant differences among the eight time intervals (all P=0.000). TV channels broadcast the most frequent ads for food, snacks, SSLCs, and beverages during the time interval from 2000 hours to 2200 hours among the eight time intervals.

CONCLUSIONS

Chinese children and adolescents may be at a high risk of exposure to unhealthy food advertising on TV. Reducing the exposure risk strongly requires multisectoral cooperation.

Prevalence of Obesity and Related Factors among Bouyei and Han Peoples in Guizhou Province, Southwest China

OBJECTIVE

To investigate the prevalence of general and abdominal obesity and associated factors in Bouyei and Han peoples.

DESIGN

A cross-sectional study was carried out in Guizhou province, southwest China in 2012, with multi-stage sampling to enroll 4551 participants aged 20 to 80 years. General and abdominal obesity were defined by World Health Organization (WHO) for Chinese. A design-based analysis was performed to evaluate prevalence of obesity and its related factors.

RESULTS

Bouyei people had a significantly lower prevalence of general obesity (4.8% vs. 10.9%, p < 0.05) and abdominal obesity (13.6% vs. 26.8%, p < 0.05) than that in Han people. Prevalence of obesity increased with age until middle-age period and declined thereafter. Men aged 40-49 years group and women aged 50-59 years group have the highest prevalence of general obesity. Prevalence of abdominal obesity was higher than that of general obesity. Middle-age, Higher income, Han people were significantly associated with an increased risk of General/abdominal obesity.

CONCLUSIONS

Bouyei people had a lower prevalence of general and abdominal obesity than the Han people. Etiological studies should be conducted to determine underlying genetic factors and dietary factors.

Association of Adiposity Indices with Platelet Distribution Width and Mean Platelet Volume in Chinese Adults

Hypoxia is a prominent characteristic of inflammatory tissue lesions. It can affect platelet function. While mean platelet volume (MPV) and platelet distribution width (PDW) are sample platelet indices, they may reflect subcinical platelet activation. To investigated associations between adiposity indices and platelet indices, 17327 eligible individuals (7677 males and 9650 females) from the Dongfeng-Tongji Cohort Study (DFTJ-Cohort Study, n=27009) were included in this study, except for 9682 individuals with missing data on demographical, lifestyle, physical indicators and diseases relative to PDW and MPV. Associations between adiposity indices including waist circumstance (WC), waist-to-height ratio (WHtR), body mass index (BMI), and MPV or PDW in the participants were analyzed using multiple logistic regressions. There were significantly negative associations between abnormal PDW and WC or WHtR for both sexes (p_trend<0.001 for all), as well as abnormal MPV and WC or WHtR among female participants (p_trend<0.05 for all). In the highest BMI groups, only females with low MPV or PDW were at greater risk for having low MPV (OR=1.33, 95% CI=1.10, 1.62 p_trend<0.001) or PDW (OR=1.34, 95% CI=1.14, 1.58, p_trend<0.001) than those who had low MPV or PDW in the corresponding lowest BMI group. The change of PDW seems more sensitive than MPV to oxidative stress and hypoxia. Associations between reduced PDW and MPV values and WC, WHtR and BMI values in Chinese female adults may help us to further investigate early changes in human body.

The global burden of obesity and the challenges of prevention

The prevalence of obesity is increasing at an alarming rate in many parts of the world. About 2 billion people are overweight and one third of them obese. The plight of the most affected populations, like those in high-income countries in North America, Australasia and Europe, has been well publicized. However, the more recent increases in population obesity in low- and middle-income countries that are now increasingly being observed have been less recognized. Based on the existing prevalence and trend data and the epidemiological evidence linking obesity with a range of physical and psychosocial health conditions, it is reasonable to describe obesity as a public health crisis that severely impairs the health and quality of life of people and adds considerably to national health-care budgets. Intersectoral action to manage and prevent obesity is urgently required to reverse current trends.

Comparison of obesity among Chinese and U.S. Special Olympic athletes with intellectual disabilities

BACKGROUND/OBJECTIVES

Obesity is a health problem in China, but there are no reports on the obesity status of Chinese citizens with intellectual disabilities (ID). Research has shown that adults with ID have higher body mass index (BMI) than adults without ID, but this information is primarily based on populations residing in North American and European countries. The purpose of this study was to compare BMI and obesity status of Chinese and U.S. Special Olympic athletes with ID.

SUBJECTS/METHODS

Height, weight, BMI and self-reported physical activity (SRPA) data from the Special Olympics 2006 U.S. National Games and 2007 Shanghai World Games databases were analyzed. Linear and logistic analyses were conducted for continuous data and dichotomous variables, respectively. Predictor variables were age, gender, country, SRPA, and obesity status according to country specific criteria. Significance was set at p < 0.05.

RESULTS

The U.S. group had significantly higher BMI values than their Chinese counterparts. Age (p = 0.001) and country (p = <0.001) were the main predictors of BMI and obesity status, even when country-specific standards of obesity classifications were used. Holding all other factors constant, each unit increase of age was associated with increased odds for obesity by a factor of 1.04 and the odds of obesity occurring in U.S. athletes was 2.47 times greater than in Chinese athletes.

CONCLUSION

Obesity is an emerging health problem for Chinese adults with ID. Participation in Special Olympics does not offset obesity in people with ID and other methods of intervention are needed to address obesity in this population segment. This is a global health concern that requires immediate attention.

Anti-obese effect of glucosamine and chitosan oligosaccharide in high-fat diet-induced obese rats

Objective: This study is to evaluate the anti-obese effects of glucosamine (GLC) and chitosan oligosaccharide (COS) on high-fat diet-induced obese rats. Methods: The rats were randomly divided into twelve groups: a normal diet group (NF), a high-fat diet group (HF), Orlistat group, GLC high-, middle-, and low-dose groups (GLC-H, GLC-M, GLC-L), COS1 (COS, number-average molecular weight ≤1000) high-, middle-, and low-dose groups (COS1-H, COS1-M, COS1-L), and COS2 (COS, number-average molecular weight ≤3000) high-, middle-, and low-dose groups (COS2-H, COS2-M, COS2-L). All groups received oral treatment by gavage once daily for a period of six weeks. Results: Rats fed with COS1 gained the least weight among all the groups (P < 0.01), and these rats lost more weight than those treated with Orlistat. In addition to the COS2-H and Orlistat groups, the serum total cholesterol (CHO) and low-density lipoprotein cholesterol (LDL-C) levels were significantly reduced in all treatment groups compared to the HF group (P < 0.01). The various doses of GLC, COS1 and COS2 reduced the expression levels of PPARγ and LXRα mRNA in the white adipose tissue. Conclusions: The results above demonstrated that GLC, COS1, and COS2 improved dyslipidemia and prevented body weight gains by inhibiting the adipocyte differentiation in obese rats induced by a high-fat diet. Thus, these agents may potentially be used to treat obesity.

Gender-specific association between tobacco smoking and central obesity among 0.5 million Chinese people: the China Kadoorie Biobank Study

Objectives

Lifestyle factors are well-known important modifiable risk factors for obesity; the association between tobacco smoking and central obesity, however, is largely unknown in the Chinese population. This study examined the relationship between smoking and central obesity in 0.5 million Chinese adults, a population with a low prevalence of general obesity, but a high prevalence of central obesity.

Subjects

A total of 487,527 adults (200,564 males and 286,963 females), aged 30-79 years, were enrolled in the baseline survey of the China Kadoorie Biobank (CKB) Study conducted during 2004-2008. Waist circumference (WC) and WC/height ratio (WHtR) were used as measures of central obesity.

Results

The prevalence of regular smokers was significantly higher among males (60.6%) than among females (2.2%). The prevalence of central obesity increased with age and BMI levels, with a significant gender difference (females>males). Of note, almost all obese adults (99.4%) were centrally obese regardless of gender. In multivariable regression analyses, adjusting for age, education, physical activity, alcohol use and survey site, regular smoking was inversely associated with BMI in males (standardized regression coefficients, β= -0.093, p<0.001) and females (β= -0.025, p<0.001). Of interest, in the BMI stratification analyses in 18 groups, all βs of regular smoking for WHtR were positive in both genders; the βs showed a significantly greater increasing trend with increasing BMI in males than in females. In the analyses with model adjustment for BMI, the positive associations between regular smoking and WHtR were stronger in males (β= 0.021, p<0.001) than in females (β= 0.008, p<0.001) (p<0.001 for gender difference). WC showed considerably consistent results.

Conclusions

The data indicate that tobacco smoking is an important risk factor for central obesity, but the association is gender-specific and depends on the adjustment for general obesity.

Assessing dietary quality of older Chinese people using the Chinese Diet Balance Index (DBI)

Background/Objectives

Few studies have applied the Chinese Diet Balance Index (DBI) in evaluating dietary quality for Chinese people. The present cross-sectional study assessed dietary quality based on DBI for older people, and the associated factors, in four socioeconomically distinct regions in China.

Methods

The China Health and Nutrition Survey (CHNS) involves 2745 older Chinese people, aged 60 or over, from four regions (Northeast, East Coast, Central and West) in 2009. Dietary data were obtained by interviews using 24 hour-recall over three consecutive days. Four indicators: Total Score (TS), Lower Bound Score (LBS), Higher Bound Score (HBS) and Diet Quality Distance (DQD) from DBI were calculated for assessing dietary quality in different aspects.

Results

68.9% of older people had different levels of excessive cereals intake. More than 50% of older people had moderate or severe surplus of oil (64.9%) and salt (58.6%). Intake of vegetables and fruit, milk and soybeans, water, and dietary variety were insufficient, especially for milk and soybeans. 80.8% of people had moderate or severe unbalanced diet consumption. The largest differences of DQD scores have been found for people with different education levels and urbanicity levels. People with higher education levels have lower DQD scores (p<0.001), and people living in medium and low urbanicity areas had 2.8 and 8.9 higher DQD scores than their high urbanicity counterparts (p<0.001). Also, significant differences of DQD scores have been found according to gender, marital status, work status and regions (p<0.001).

Conclusion

DBI can reveal problems of dietary quality for older Chinese people. Rectifying unbalanced diet intake may lead to prevention of non-communicable diseases (NCDs). Dieticians and health care professionals need to increase dissemination and uptake of nutrition education, with interventions targeted at regions of lower socioeconomic status.

Use of quantile regression to investigate changes in the body mass index distribution of Chinese adults aged 18-60 years: a longitudinal study

Background

Traditional linear regression analyses have detected increasing trends in the incidence of overweight/obesity among both genders in China. However, these previous regression analyses were limited in their ability to capture cross-distribution variations among effects. The objective of our study was to analyze the change in the body mass index (BMI) distribution of adults and investigated the relationships between the key covariates and the BMI distribution.

Methods

We used longitudinal data from the China Health and Nutrition Surveys (CHNS) in 1991, 1993, 1997, 2000, 2004, 2006, 2009, and 2011, with at least two waves of data collection. In total, 17,819 participants aged 18–60 years (N = 8587 men and 9232 women) were included in the final analysis with 48,900 observations. The lambda-mu-sigma (LMS) method was used to describe changes in the BMI distribution. Separate sex-stratified longitudinal quantile regression (QR) analyses were used to investigate changes in the BMI distribution over time.

Results

The main characteristics of the BMI changes in both genders were that the curves shifted to the right and the distributions became wider. All of the BMI percentile curves tended to increase from 1991 to 2011, where the levels increased more in the higher percentiles. The QR analyses showed that these patterns remain consistent after adjusting for individual and community level factors. Physical activity (PA) had a negative association with BMI for both genders in all percentiles. Income and energy intake were associated with positive changes in male BMI in the upper percentile. Sedentary time had a positive association with female BMI in the middle percentile. Compared with less educated women, women with senior school education at 75^th percentile had 0.951 kg/m² lower BMIs.

Conclusions

This longitudinal quantile regression suggests that effects of different covariates worked differently across the BMI distribution. Since social and economic characteristics in China have underlined the significant disparities in many aspects, national strategies to tackle overweight/obesity should be tailored as appropriate for various segments.

Changes in individual weight status based on body mass index and waist circumference in Hong Kong Chinese

Background

Weight change predicted diseases and mortality. We investigate 3-year changes in individual body mass index (BMI) and waist circumference in Hong Kong Chinese adults.

Methods

In the Population Health Survey, 7084 adults in 2003 (baseline) were followed up in 2006. Longitudinal anthropometric data were available in 2941 (41.5%) for BMI and 2956 for waist circumference. Weight status and central obesity were based on objectively measured BMI and waist circumference using Asian standards.

Results

Mean BMI (SD) increased from 22.8 (3.62) to 23.1 (3.95) (p<0.001) with 1.3 percentage point increase in prevalence of overweight and obesity (from 44.3% to 45.6%). One in 5 (22.0%) normal or underweight baseline respondents became overweight or obese and a similar proportion (24.8%) of overweight and obese respondents became normal or underweight. Prevalence of central obesity increased from 28.3% to 32.4% (p<0.001) with a non-significantly greater increase in women (30.0% to 38.1%) than men (23.0% to 26.1%) (p=0.63). A higher proportion of centrally obese respondents returned to normal (29.4%) than normal respondents developing central obesity (17.4%).

Conclusions

This is one of the few studies in Chinese, which found dynamic longitudinal changes (increase/stable/decrease) in individual weight status and waist circumference. Future studies with better follow-up and investigating the causes of such changes are warranted.

Are the recent secular increases in the waist circumference of adults independent of changes in BMI?

BACKGROUND

Several studies showed that the waist circumference of US adults has increased over the past 25 y. However, because of the high correlation between waist circumference and body mass index (BMI; in kg/m²) (r ∼ 0.9), it is uncertain if these trends in waist circumference exceed those expected on the basis of BMI changes over this time period.

OBJECTIVE

We assessed whether the recent trend in waist circumference was independent of changes in BMI, age, and race-ethnicity.

DESIGN

We analyzed data from the 1999-2000 through 2011-2012 cycles of the NHANES.

RESULTS

The mean waist circumference increased by ∼2 cm (in men) and ∼4 cm (in women) in adults in the United States over this 12-y period. In men, this increase was very close to what would be expected because of the 0.7 increase in mean BMI over this period. However, in women, most of the secular increase in waist circumference appeared to be independent of changes in BMI (mean: 0.6), age, and race-ethnicity over the 12-y period. We estimated that, independent of changes in these covariates, the mean waist circumference increased by 0.2 cm in men and 2.4 cm in women from 1999-2000 through 2011-2012; only the latter estimate was statistically significant.

CONCLUSIONS

Our results indicate that, in women but not men, the recent secular trend in waist circumference is greater than what would be expected on the basis of changes in BMI. Possible reasons for this secular increase, along with sex differences, are uncertain.

Type 2 diabetes mellitus incidence in Chinese: contributions of overweight and obesity

AIMS

To estimate the incidence of Type 2 diabetes mellitus (T2DM) and the number of those with T2DM attributable to overweight and obesity in China.

METHODS

We conducted a prospective cohort study among 15680 participants (46.4%, men) aged 35-74 years. The mean duration of follow-up was 8.0 years. We examined the relationship between overweight, obesity and risk of T2DM by Cox proportional hazards models. Population attributable risk (PAR) of overweight and obesity was also calculated. Moreover, we estimated the number of T2DM events attributed to overweight and obesity using PAR, incidence of T2DM and the population size of China in 2010.

RESULTS

During a mean follow-up of 8.0 years, the age-standardized incidence of T2DM was 9.5 per 1000 person-years in men and 9.2 in women. Overweight accounted for 28.3% (95% confidence interval [CI]: 20.1, 36.2) of incident T2DM among men and 31.3% (95% CI: 25.5, 36.9) among women. The corresponding PAR of obesity was 10.1% (95% CI: 6.0, 14.2) among men and 16.8% (95% CI: 12.0, 21.6) among women. Approximately 3.32 million (95% CI: 2.47, 4.24) incident T2DM were attributable to overweight and obesity in Chinese adults who were 35 to 74 years in 2010.

CONCLUSION

Our results indicate that incident T2DM is mainly attributable to overweight and obesity in China. It is extremely important to advocate healthy lifestyle and prevent excessive weight gain for reducing T2DM burden in China.

Do older Chinese people's diets meet the Chinese Food Pagoda guidelines? Results from the China Health and Nutrition Survey 2009

OBJECTIVE

To evaluate dietary intake based on the Chinese Food Pagoda (CFP) and to determine what factors may be associated with adherence to CFP guidelines for older Chinese.

DESIGN

This cross-sectional population-based study used 24 h recall over three consecutive days to assess dietary intake and adherence to CFP among older Chinese participating in the China Health and Nutrition Survey 2009.

SETTING

Nine provinces across four diverse regions (Northeast, East Coast, Central and West).

SUBJECTS

A total of 2745 older Chinese, aged 60-69 years (n 1563) and ≥70 years (n 1182), with dietary data.

RESULTS

None of the participants reached all ten food group recommendations. More than half of the participants exceeded the recommended amount for grains (63%), oil (62·8%) and salt (55·7%). Ten per cent of the participants consumed dairy, while merely 0·5% met the recommended amount. Average Chinese Food Pagoda Score (CFPS) was 3·3 in men and 3·5 in women, far below the maximum possible score of 10. Women had 0·26 higher CFPS than men (P<0·001; 95% CI 0·16, 0·36). People living in medium and high urbanicity areas had significantly higher scores than those living in low urbanicity areas (P<0·001). Also, there were significant differences in CFPS according to gender, BMI, work status, education level and region.

CONCLUSIONS

Few older Chinese are meeting the intake of the various food groups based on the recommendations in the CFP guidelines, thus increasing the risk of malnutrition and non-communicable diseases. Action is needed to increase dissemination and uptake of nutrition education, with interventions targeted at socio-economic regions. Moreover, specific dietary guidelines for older Chinese people should be developed.

The associations of month of birth with body mass index, waist circumference, and leg length: findings from the China Kadoorie Biobank of 0.5 million adults

Background

Season of birth (SoB) has been linked with various health outcomes. This study aimed to examine the associations between month of birth (MoB) and adult measures of leg length (LL), body mass index (BMI), and waist circumference (WC).

Methods

We analysed survey data from 10 geographically diverse areas of China obtained through the China Kadoorie Biobank. Analysis included 487 529 adults with BMI ≥ 18.5 kg/m². A general linear model was used to examine the associations between MoB and adult measures of LL, BMI, and WC, adjusted for survey site, sex, age, education level, smoking habit, alcohol consumption, physical activity level, sedentary leisure time, height (only for WC and LL), and hip circumference (only for LL).

Results

MoB was independently associated with both BMI and WC. Birth months in which participants had higher measures of adiposity were March–July for BMI and March–June for WC. The peak differences were 0.14 kg/m² for BMI and 0.47 cm for WC. The association between MoB and LL depended on survey site. Participants who were born in February–August in four sites (Harbin, Henan, Gansu, and Hunan) had the shortest LL (all P < 0.01). The peak difference in mean LL was 0.21 cm. No statistically significant association between MoB and LL was noted in the other sites (Qingdao, Suzhou, Sichuan, Zhejiang, Liuzhou, and Haikou).

Conclusions

These findings suggest that MoB is associated with variations in adult adiposity measures and LL among Chinese adults. Low exposure to ultraviolet B radiation and subsequent reduced levels of vitamin D during the late second and early third trimesters may be involved in these phenomena.

Soft drink consumption is positively associated with increased waist circumference and 10-year incidence of abdominal obesity in Spanish adults

BACKGROUND

The accumulation of abdominal fat increases risk of metabolic disorders and premature death. There is a dearth of prospective data on the association between caloric beverage consumption and surrogate markers of abdominal adiposity.

OBJECTIVE

The aim of this study was to assess the relation between consumption of nonalcoholic caloric beverages, including soft drinks, fruit juice, whole milk, and skim and low-fat milk, and changes in waist circumference (WC) and odds of 10-y incidence of abdominal obesity.

METHODS

We conducted a prospective, population-based study of 2181 Spanish men and women aged 25-74 y who were followed from 2000 to 2009. We measured weight, height, and WC, and recorded data on diet and leisure-time physical activity (LTPA) with the use of validated questionnaires. We fit multivariable linear and logistic regression models.

RESULTS

A 100 kcal increase in soft drink consumption was associated with a 1.1 cm increase in WC (P = 0.018) after 10 y of follow-up. Substitution of 100 kcal of soft drinks with 100 kcal of whole milk or 100 kcal of juice was associated with a 1.3 cm (95% CI: 0.3, 2.4) and 1.1 cm (95% CI: 0.03, 2.2) decrease in WC, respectively. Increasing consumption of soft drinks from baseline to follow-up led to WC gain compared with maintaining nonconsumption. Greater soft drink consumption was positively associated (P = 0.029) with increased odds of 10-y incidence of abdominal obesity.

CONCLUSION

Adults' consumption of soft drinks was associated with increased WC and odds of 10-y incidence of abdominal obesity. This association was moderate but consistent in all statistical models.

Obesity and its relationship with hypertension among adults 50 years and older in Jinan, China

Background

The relationship between obesity and hypertension varies with geographical area, race and definitions of obesity. Our study aimed to investigate the prevalence of obesity using standard Chinese criteria based on the body mass index (BMI) and the waist circumference (WC) and to examine the association between obesity and hypertension among middle-aged and elderly people in Jinan city.

Methods

This cross-sectional study examined 1,870 subjects from the blocks randomly selected from among the 6 communities of Jinan, China in 2011–2012. The Student's t-test was used to compare numerical data, and the χ² test was used to compare categorical data. Multivariate logistic regression analyses were performed to assess the effects of general and central obesity on hypertension after adjusting for age or for education level, smoking, alcohol consumption, and continuous age.

Results

The prevalence of general obesity among people age 50 years and older was 21.1% (17.0% for males and 23.1% for females), and the prevalence of central obesity was 77.8% for men and 78.7% for women. For men, compared with a normal BMI, the ORs and 95% CIs for overweight and general obesity were 1.853 (1.252, 2.744) and 3.422 (1.894, 6.182), respectively, after adjusting for age, smoking, alcohol consumption and educational level. Compared with a normal WC, the ORs and 95% CIs for central obesity were 2.334 (1.573, 3.465) and 2.318 (1.544, 3.479), respectively, for men. For women, compared with a normal BMI, the ORs and 95% CIs were 1.942 (1.473, 2.599) and 4.011 (2.817, 5.712), respectively, after adjusting for age, smoking, alcohol consumption and educational level. Compared with a normal WC, the ORs and 95% CIs for central obesity were 2.488 (1.865, 3.319) and 2.379 (1.773, 3.192), respectively, for women.

Conclusions

The relationship between hypertension and general obesity was stronger than the relationship between hypertension and either overweight or central obesity in both genders.

Oral vitamin D supplementation has a lower bioavailability and reduces hypersecretion of parathyroid hormone and insulin resistance in obese Chinese males

OBJECTIVE

To examine the vitamin D status, SNP of the vitamin D receptor gene (VDR) and the effects of vitamin D supplementation on parathyroid hormone and insulin secretion in adult males with obesity or normal weight in a subtropical Chinese city.

DESIGN

An intervention trial.

SETTING

Shenzhen City, Guangdong Province, China.

SUBJECTS

From a cross-sectional survey conducted from June to July, eighty-two normal-weight and ninety-nine obese males (18-69 years) were screened to analyse their vitamin D status and for five SNP of VDR. From these individuals, in the same season of a different year, obese and normal-weight male volunteers (twenty-one per group) were included for an intervention trial with oral vitamin D supplementation at 1250 µg/week for 8 weeks.

RESULTS

For the survey, there was no significant difference (P>0·05) in baseline circulating 25-hydroxyvitamin D concentrations or in the percentages of participants in different categories of vitamin D status between the two groups. The VDR SNP, rs3782905, was significantly associated with obesity (P=0·043), but none of the examined SNP were correlated with serum 25-hydroxyvitamin D when adjusted for age, BMI and study group. After vitamin D supplementation, serum 25-hydroxyvitamin D concentration, hypersecretions of parathyroid hormone and insulin, and insulin resistance in the obese were changed beneficially (P<0·05); however, the increase in serum 25-hydroxyvitamin D was less than that of the normal-weight men.

CONCLUSIONS

For obese and normal-weight men of subtropical China, the summer baseline vitamin D status was similar. However, oral vitamin D supplementation revealed a decreased bioavailability of vitamin D in obese men and ameliorated their hypersecretion of parathyroid hormone and insulin resistance.

The predictive value of waist-to-height ratio for ischemic stroke in a population-based prospective cohort study among Mongolian men in China

Objective

To explore the associations between waist-to-height ratio (WHtR), body mass index (BMI) and waist circumference (WC) and risk of ischemic stroke among Mongolian men in China.

Methods

A population-based prospective cohort study was conducted from June 2003 to July 2012 in Inner Mongolia, an autonomous region in north China. A total of 1034 men aged 20 years and older free of cardiovascular disease were included in the cohort and followed up for an average of 9.2 years. The subjects were divided into four groups by WHtR levels (WHtR<0.40, 0.40≤WHtR≤0.50, 0.50<WHtR≤0.60, WHtR>0.60). The cumulative survival rates of ischemic stroke among the four groups were estimated with the Kaplan-Meier curves and compared by log-rank test. Cox proportional hazards models and Receiver Operating Characteristic (ROC) curves were employed to evaluate the associations between obesity indices and ischemic stroke.

Results

A total of 47 ischemic stroke patients were observed during the follow-up period. The cumulative incidence and incidence density of ischemic stroke were 4.55% and 507.61/100 000 person-years, respectively. After the major risk factors were adjusted, individuals with WHtR>0.60 had a 3.56-fold increased risk of ischemic stroke compared with those with 0.40≤WHtR≤0.50. Hazard ratio (HR) and 95% confidence intervals (CI) of ischemic stroke for a 1-SD increase in WHtR was 1.34(95% CI: 1.00–1.81). After adding BMI or WC to models, higher WHtR remained significantly associated with increased risk of ischemic stroke. The Kaplan-Meier survival curves showed that the cumulative survival rate in the group with WHtR>0.60 was significantly lower than in the group with 0.40≤WHtR≤0.50 (log-rank test, P = 0.025). The areas under the curve for each index were as follows: 0.586 for WHtR, 0.543 for WC; 0.566 for BMI.

Conclusions

Higher WHtR is associated with risk of ischemic stroke in Mongolian males. WHtR may be useful in predicting ischemic stroke incidence in males.

An update on overweight and obesity in rural Northeast China: from lifestyle risk factors to cardiometabolic comorbidities

Background

Not enough is known about the prevalence of overweight and obesity in rural China in the current decade. We aim to update our knowledge of the prevalence of obesity and its associated risk factors and comorbidities in a large population sample in rural Northeast China.

Methods

A population-based survey of 11,579 participants aged 35 years and older was conducted in rural areas of Liaoning Province during 2012–2013. Anthropometric measurements, information on health-related variables and blood biochemical indexes were collected by well-trained personnel.

Results

The prevalence of general obesity and overweight was found to be 7.8% and 37.2%, respectively. The overall prevalence of abdominal obesity was 15.1%. Female gender, ethnic minority, middle-school education and a family income of 5,000–20,000 CNY per year were found to be risk factors for general obesity, while older age, female gender, ethnic minority and longer sleep duration (>8 h/d) increased the risk of abdominal obesity, after adjusting for confounders. Overweight and obese participants had significantly higher risks to develop prehypertension, hypertension, high LDL-C and low HDL-C compared with normal weight participants, while abdominal obesity was associated with increased risks of diabetes and high TG after adjusted for multiple factors. Compared with participants with a normal BMI and no abdominal obesity, the participants classified as abdominally obese and normal BMI; as abdominally obese and overweight; and abdominally obese and generally obese each had a progressive increase in the odds of hypertension (OR: 1.961, 95% CI: 1.154 to 3.331, OR: 2.744, 95% CI: 2.126 to 3.541, and OR: 8.990, 95% CI: 5.858 to 13.795, respectively) and high TG (OR: 3.165, 95% CI: 2.183 to 4.588, OR: 3.980, 95% CI: 3.332 to 4.755, and OR: 4.340, 95% CI: 3.574 to 5.271, respectively).

Conclusions

The prevalence of obesity in rural Northeast China exhibited a remarkably increasing upwards trend. General and abdominal obesity were associated with different subtypes of cardiometabolic comorbidities, the combined effects of which on the comorbidities dramatically increased.

Gender differences in home environments related to childhood obesity in Nanchang, China

BACKGROUND

Childhood obesity is rapidly increasing in China, with rates doubling between 2000 and 2010. Several large, epidemiological studies have shown boys to be consistently more likely to be obese than girls. The aim of this study was to investigate gender differences in the home environment and parenting practices related to childhood obesity.

METHODS

A cross-sectional survey using a convenience sampling of 522 (86.1% response rate) primary caregivers of children ages 2-10 years was conducted in four locations in Nanchang, China, in the spring of 2013 using face-to-face, anonymous questionnaires.

RESULTS

Boys were significantly (p<0.05) more likely than girls to watch more television (TV) per week, be allowed to have snacks/sweets or soft drinks without permission, and to have sugary drinks at snacks and meals. Girls were significantly more likely than boys to have parental encouragement and support for physical activity, participate in organized sports/group activities, and have fresh fruits accessible. Parents also believed that boys eat too much junk foods or their favorite foods if not controlled. Few differences were noted in the actual physical environment in the home, including access to sports equipment, junk food availability, and access to media.

CONCLUSIONS

RESULTS indicate that parents tend to be more permissive with boys than girls, allowing them access to unhealthy foods and more TV time. These differences may contribute to the higher prevalence of obesity in boys in China.

Secular trends in the prevalence of low risk factor burden for cardiovascular disease according to obesity status among Chinese adults, 1993-2009

Background

Cardiovascular disease (CVD) and obesity are now common among Chinese. We aimed to examine secular trends in the prevalence of low risk profile and to examine whether comparable changes in the prevalence of low risk profile across waist circumference (WC) groups and body mass index (BMI) categories have occurred.

Methods

We used data from the nationwide China Health and Nutrition Survey conducted in 1993, 1997, 2000, 2004, 2006, and 2009. There were 7274, 8368, 9369, 8948, 8786, and 9278 participants included in the analyses across the six study periods. We created an index of low risk factor burden from the following variables: not currently smoking, BMI < 25 kg/m², WC < 90/80 cm in men/women, untreated systolic/diastolic blood pressure < 120/80 mmHg, and not having been previously diagnosed with diabetes.

Results

During the period of 1993–2009, the age-adjusted prevalence of low risk profile decreased from 16.2 to 11.5% among men and from 46.3 to 34.6% among women (both P < 0.001); Similar significant trends were observed in all age groups, rural/urban settings, education groups, WC status and BMI categories. The change in the prevalence of low risk profile was more striking among obese persons (P for interaction terms cohort *BMI were < 0.001). In 2009, 2.0 and 25.6% among central obese men and women had a low risk profile; Of note, was that 0.1 and 0.3% general obese men and women had a low risk profile.

Conclusions

The prevalence of low risk profile declined considerably over the past 17 years in all demographic groups, WC status, and BMI categories. Public health prevention strategies are urgently needed.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-961) contains supplementary material, which is available to authorized users.

Ethnic differences in prevalence of general obesity and abdominal obesity among low-income rural Kazakh and Uyghur adults in far western China and implications in preventive public health

BACKGROUND

The global pandemic of obesity has become a disastrous public health issue that needs urgent attention. Previous studies have concentrated in high-income urban settings and few cover low-income rural settings especially nomadic residents in mountain areas. This study focused on low-income rural and nomadic minority people residing in China's far west and investigated their prevalence and ethnic differences of obesity.

METHODS

A questionnaire-based survey and physical examination of 8,036 individuals were conducted during 2009-2010, using stratified cluster random sampling method in nomadic Kazakhs and rural Uyghur residents (≥ 18 years old) in 18 villages, Xinjiang, China, about 4,407 km away from capital Beijing. Obesity was defined by BMI and WC.

RESULTS

The overall prevalence of general and abdominal obesity in Kazakh adults were 18.3% and 60.0%, respectively and in Uyghur, 7.6% and 54.5%, respectively. Female's prevalence of obesity was higher than male's for general obesity (45-54 age group in Uyghur, P = 0.041) and abdominal obesity (≥ 55 years in Kazakhs, P(55 ∼) = 0.010, P(65 ∼) = 0.001; and ≥ 18 years in Uyghurs, P<0.001). Kazakh's prevalence of obesity was higher than Uyghur's (general obesity: ≥ 35 years, P<0.001; abdominal obesity: ≥ 25 years in males and ≥ 65 years in females, P<0.01). The prevalence of obesity increased after 18 years old and subsequently decreased after 55 years old. Meat consumption, older age, and female gender had a higher risk of obesity in these two minorities.

CONCLUSIONS

Both general and abdominal obesity were common in rural ethnic Kazakhs and Uyghurs. The prevalence rates were different in these two minorities depending on ethnicity, gender, and age. Kazakhs, females and elderly people may be prioritized in prevention of obesity in western China. Because of cost-effectiveness in measuring BMI and WC, we recommend that BMI and WC be integrated into local preventive policies in public health toward screening obesity and related diseases in low-income rural minorities.