Jianhua Piao

Comparison of adiponectin, leptin and leptin to adiponectin ratio as diagnostic marker for metabolic syndrome in older adults of Chinese major cities

The aim of this study was to compare the strength of association between metabolic syndrome (MetS) and adiponectin, leptin and leptin to adiponectin ratio (L/A) in older Chinese. This study included 950 males (220 with MetS) and 1096 females (452 with MetS), aged 60-96 years from 18 major cities of the 2002 China National Nutrition and Health Survey. The associations of adiponectin, leptin and L/A with components of MetS and MetS were examined using logistic regression and the receiver operating characteristic (ROC) curves. The correlation coefficients of MetS components except fasting glucose with leptin were similar to those with L/A and higher than those with adiponectin. After adjusting for age and BMI, the odds ratio for MetS corresponding to 1 SD change in L/A was higher than those for leptin and adiponectin. L/A had highest area under the curve (AUC) for MetS. However, there was no statistically significant difference in AUC between leptin and L/A, and both indices produced a significantly higher AUC than adiponectin. In conclusion, L/A and leptin may be better diagnostic markers for MetS than adiponectin. After adjusting for BMI, L/A has better ability for correctly classifying subjects with and without MetS than adiponectin or leptin alone.

Prevalence of the metabolic syndrome in Chinese adolescents.

Since national figures on the occurrence of metabolic syndrome among Chinese adolescents are lacking, this study aims to estimate its prevalence and distribution among Chinese youngsters. The 2002 China National Nutrition and Health Survey is a nationally representative cross-sectional study. Applying the criteria for US adolescents, we estimated the prevalence of metabolic syndrome among 2761 adolescents aged 15 to 19 years. The prevalence of metabolic syndrome among Chinese adolescents overall was 3.7 % (10 % in US adolescents). It was 35.2 %, 23.4 % and 2.3 % among adolescents who were overweight (BMI > or = 95th percentile), at risk of overweight (BMI between 85th and 95th percentile) and normal weight (BMI below the 85th percentile), respectively. Urban boys had the highest rate (5.8 %) compared with girls and rural youngsters. Among adolescents who had a BMI > or = 85th percentile and one or two parent(s) with metabolic syndrome, the prevalence was 46.4 %. A total of 96 % of overweight adolescents had at least one and 74.1 % overweight adolescents had at least two abnormalities of metabolic syndrome. Based on these figures, it is estimated that more than three million Chinese adolescents have metabolic syndrome. Both overweight and metabolic syndrome prevalence among adolescents are still relatively low in China, but the prevalence of metabolic syndrome among Chinese overweight adolescents is similar to those living in the USA.

Childhood obesity and its health consequence in China

Analyses of data from the representative 2002 National Nutrition and Health Survey were used to assess the likelihood of metabolic complications of overweight and obesity in Chinese children aged 7–17 years. Chinese criteria for body mass index classification were used for overweight and obesity with the 75th percentile US adolescent values for waist circumferences and all the metabolic criteria for blood pressure, lipids, fasting glucose established for US adolescents. Diabetes in 7–12‐year‐olds was 0.2% and 0.4% in children aged 12–18 years. Prevalences of dyslipidaemia (61.9%), hypertriglyceridaemia (18.2%) and low high‐density lipoprotein cholesterol (56.1%) were high and 16.0% of 15–18 years had hypertension. The overall prevalence of the metabolic syndrome was 3.3% with more than half the children having at least one metabolic abnormality and 19.8% having at least two. All the metabolic parameters were significantly elevated in the overweight and obese children except high‐density lipoprotein cholesterol. These data emphasize the marked sensitivity of Chinese children to the metabolic complications of overweight and obesity and amplify the need for early preventive measures.

Postprandial glycaemic and insulinaemic responses to GM-resistant starch-enriched rice and the production of fermentation-related H2 in healthy Chinese adults.

Consumption of resistant starch (RS)-enriched foods is associated with decrease in the postprandial glycaemic and insulinaemic responses, accompanied by the production of fermentation-related gases in the large bowel. The present study aimed to determine the postprandial glycaemic and insulinaemic responses to the GM RS-enriched rice and the fermentation-related production of H2 in young and healthy Chinese adults. A total of sixteen young adults (nine men and seven women) were recruited and divided into three groups. Their postprandial glycaemic and insulinaemic responses to 40 g glucose, carbohydrates of RS or wild-type (WT) rice were tested by a crossover model with a washout period of 7 d. The concentrations of blood glucose and insulin as well as breath H2 were measured before and after food intake. Although the mean concentrations of fasting blood glucose, insulin and breath H2 were similar, consumption of the RS rice significantly decreased the values of glycaemic index (GI) and insulin index (II), as compared with the intake of WT rice (48.4 (sem 21.8) v. 77.4 (sem 34.9) for GI, 34.2 (sem 18.9) v. 54.4 (sem 22.4) for II, P < 0.05), respectively. Conversely, intake of the RS rice meal significantly elevated the concentrations of breath H2, as compared with WT rice (38.9 (sem 17.6) v. 10.5 (sem 3.7) parts per million for peak levels of breath H2, P < 0.05) through a period of 16-h tests. Consumption of the GM RS-enriched rice meal decreased the postprandial glycaemic and insulinaemic responses and promoted RS fermentation-related production of H2 in the large bowel of young and healthy Chinese adults.

Long-term toxicity study on transgenic rice with Cry1Ac and sck genes

In the present work, we evaluated the chronic effects of the transgenic insect-resistant rice carrying Cry1Ac and sck genes on Sprague-Dawley (SD) rats through a 78-week feeding study. Based on the gender and weight, 180 SD rats were randomly and evenly assigned into three groups. GM rice and non-GM rice were separately formulated into diets at high levels. AIN-93 diet was used as a nutritional control. Body weight, food consumption, hematology and serum chemistry were monitored regularly. Rats were sacrificed for organ weight measurement and pathological examination at 52 weeks and 78 weeks. Body weight, food consumption, mortality rates, tumor incidences and pathological findings showed no significant difference among the three groups. Although certain differences in some hematology, serum chemistry parameters and relative organ weights were observed between GM rice group and control groups, they were not considered as treatment-related. Taken together, long-term intake of transgenic rice carrying Cry1Ac and sck genes at a high level exerts no unintended adverse effects on rats.

Geographic variation in the prevalence of overweight and economic status in Chinese adults

China is experiencing a rapid increase in overweight and related conditions. This study describes the geographic variation in BMI levels and the prevalence of overweight and underweight in Chinese adults, and assesses their relations with regional Gross Domestic Product (GDP) per capita levels. BMI values and the prevalence of overweight and underweight in 143 522 adults from the Chinese National Nutrition and Health Survey (2002) were calculated according to geographic regions in China. Their correlations with GDP were assessed. Linear and logistic regressions were used to adjust for age, sex and city-country composition. BMI and the prevalence of overweight were highest in the Bohai coastal regions while lowest in southern provinces such as Guangdong, Guangxi, Yunnan, Hunan and Fujian. Mean BMI values ranged from 20.72 to 25.48 kg/m2, and the prevalence of overweight ranged from 6.6 to 53.9 %. BMI and the prevalence of overweight were positively correlated with economic development, particularly in the northern regions. However, for regions with similar GDP per capita levels, those in the south had substantially lower BMI and lower prevalence of overweight than those in the north. Interestingly, some southern regions with high GDP per capita had low BMI and low prevalence of overweight. The prevalence of underweight was highest in the south. Substantial geographic variations in the prevalence of overweight and underweight exist in China. Such variations cannot be fully explained by the differences in economic status. China is currently facing challenges of both overweight and underweight but priorities vary in different regions.

Association between adiponectin and metabolic syndrome in older adults from major cities of China

OBJECTIVE To investigate the association between adiponectin and metabolic syndrome (MetS) and related diseases in older adults from major cities of China. METHODS A total of 2 049 adults at the age of 60-96 years from 18 major cities of China were enrolled in the study. Plasma adiponectin and insulin concentrations were measured. Insulin resistance was assessed by homeostasis model assessment of insulin resistance (HOMA-IR). The definitions proposed by International Diabetes Federation (IDF) and American Heart Association/National Heart, Lung, and Blood Institute (AHA/NLHBI) were used to identify MetS. RESULTS The adiponectin concentration increased with the advance of age and was higher in women than in men. The sex specific adiponectin concentration was inversely correlated with body mass index (BMI), waist circumference, diastolic blood pressure, triglycerides, glucose and fasting blood insulin, and positively correlated with HDL-C (P < 0.001). The adiponectin concentration decreased with increasing MetS components. Compared with the 4th sex-specific adiponectin quartile, the odds ratio (OR) for prevalent MetS-IDF and MetS-AHA/NLHBI in subjects of the 1st quartile group was 3.25 (95% CI: 2.24, 4.71) and 3.21 (95% CI: 2.26, 4.55), respectively. The association was independent of age, sex, life-style factors, medication, family history of chronic diseases, BMI, and HOMA-IR. The OR for MetS was much higher than those of MetS components and its related diseases. CONCLUSION Adiponectin is strongly associated with MetS independent of insulin resistance and obesity in older adults from major cities in China. The adiponectin concentration is a useful predictor for the risk of MetS.

Correlation of Serum Leptin Level with Bone Mineral Density and Bone Turnover Markers in Chinese Adolescent Dancers

OBJECTIVE To investigate plasma leptin concentrations in adolescent female dancers and to determine whether leptin has some effects on their bone mineral density (BMD) and bone turnover markers. METHODS Sixty dancers aged 15-17 years and 77 healthy controls were enrolled in the study. Bone mineral density (BMD) and body composition were detected by dual energy X-ray absorptiometry. Serum leptin concentrations were measured by radioimmunoassay (RIA). Two bone turnover markers, bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase(TRACP), were determined by ELISA. RESULTS The dancers had a lower fat mass and a lower leptin level than the controls, while they had a relatively higher BMD of the total body and legs after adjustment for BMI and age. The levels of bone resorption and formation of markers were higher in the dancers than in the controls. Leptin was positively correlated with BMI, body weight, fat mass, and percentage of body fat. In dancers, Leptin was positively correlated with the BMD of the total body and the left leg. However, after adjustment for BMI, no correlation of serum leptin concentrations with BMD values was found in either dancers or controls. Nor correlation was found between leptin and bone turnover markers after adjustment for BMI. CONCLUSION The leptin profile is different between the controls and the dancers with a lower BMI and a lower fat mass. Circulating plasma leptin level depends on BMI and is not a direct determinant of BMD in Chinese adolescent dancers.

Comparison of two 25-hydroxyvitamin D immunoassays to liquid chromatography-tandem mass spectrometry in assessing samples from the Chinese population.

BACKGROUND We compared the utility of two 25-OH-D immunoassays to a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for assessing human serum samples from the Chinese population. METHODS In total, 451 Chinese serum samples were tested using the IDS 25-Hydroxy Vitamin D EIA kits and the LC-MS/MS 25-OH-D method. Of these, 239 samples were also analysed using DiaSorin 25-Hydroxyvitamin D RIA kits. RESULTS The regression coefficients (r) between LC-MS/MS and immunoassays were 0.8430 (95% CI: 0.8140-0.8678) for IDS-EIA and 0.8187 (95% CI: 0.7720-0.8566) for DiaSorin-RIA. Using the Passing-Bablok analysis, IDS-EIA and DiaSorin-RIA yielded results equivalent to those from LC-MS/MS. However, IDS-EIA showed negative bias and DiaSorin-RIA showed positive bias when compared to LC-MS/MS, as indicated by the Bland-Altman plots. By the kappa test, both IDS-EIA and DiaSorin-RIA were in acceptable agreement with LC-MS/MS in the assessment of vitamin D deficiency and insufficiency. CONCLUSION Although some systematic bias was found, the DiaSorin-RIA and IDS-EIA kits met the minimum performance goal for 25-OH-D measurement and can be recommended for routine use in the Chinese population. However, further studies are needed to assess 25-OH-D measurement immunoassays with lower bias and that are more suitable for the Chinese population.

Relatively high bone mineral density in Chinese adolescent dancers despite lower energy intake and menstrual disorder.

OBJECTIVE The effect of dietary restriction, intense exercise and menstrual dysfunction on bone mineral density remains controversial. The aim of this study was to assess the skeletal health status and relationship between bone mineral density and nutrient intake, menstrual status, estrogen level and other factos in Chinese adolescent dancers. METHODS Sixty dancers and 77 healthy controls underwent measurements of bone density, body composition, and estrogen level. Nutrient intake, menstrual status and physical activity were assessed with questionnaires. The correlation between these factors were analyzed. RESULTS The dancers under study had a significantly lean body mass index (18.3 +/- 1.4 kg/m2 vs. 21.7 +/- 3.1 kg/m2), lower percentage of body fat (0.25 +/- 0.05 vs. 0.34 +/- 0.04) and later age at menarche (14.0 +/- 0.9 y vs. 13.0 +/- 1.3 y), and the estrogen level, daily calorie and fat intake in them were also lower than in the controls. All the dancers undertook intensive physical activity every day and up to 69% of them suffered from irregular menarche. Yet they had relatively high BMD and BMC of the total body and legs than the controls after adjusting for BMI and age. Site-specific BMD was positively correlated to BMI, body composition and training hours per week and negatively correlated to the age at menarche and menstrual frequency. CONCLUSIONS The relatively high BMD and BMC of the dancers at the total body and legs were probably caused by high levels of weight-bearing physical activity. To ameliorate disordered eating, especially low energy intake might be helpful to prevent the Triad and to improve the bone health in adolescent dancers.