Xuzhen Qin

The high prevalence of hypovitaminosis D in China: a multicenter vitamin D status survey.

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25OHD analogues and vacuum blood collection tubes dramatically affect the accuracy of automated immunoassays

Variations in vitamin D quantification methods are large, and influences of vitamin D analogues and blood collection methods have not been systematically examined. We evaluated the effects of vitamin D analogues 25OHD2 and 3-epi 25OHD3 and blood collection methods on vitamin D measurement, using five immunoassay systems and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum samples (332) were selected from routine vitamin D assay requests, including samples with or without 25OHD2 or 3-epi 25OHD3, and analysed using various immunoassay systems. In samples with no 25OHD2 or 3-epi 25OHD3, all immunoassays correlated well with LC-MS/MS. However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator. When 25OHD2 or 3-epi 25OHD3 was present, correlations and clinical agreement decreased for all immunoassays. Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives. Bias decreased and clinical agreement improved significantly when using tubes with no additives. In conclusion, most automated immunoassays showed acceptable correlation and agreement with LC-MS/MS; however, 25OHD analogues and blood collection tubes dramatically affected accuracy.

Prevalence and Clustering of Major Cardiovascular Risk Factors in China: A Recent Cross-Sectional Survey.

AbstractCardiovascular disease is the leading cause of death in the Chinese population. Although general prevalence estimates of cardiovascular risk factors (CVRFs) are available for Chinese adults, prevalence estimates covering all adult age groups by race/ethnicity have not been reported. The aim of this study is to estimate the current prevalence and clustering of major CVRFs in Chinese adults, including a plurality of ethnic minorities.A cross-sectional survey was conducted in a nationally representative sample of 23,010 adults aged 18 years and older from 2007 to 2011. Questionnaires and physical examinations were performed, and fasting blood was collected for laboratory measurements. The prevalence of traditional CVRFs, including hypertension, diabetes, dyslipidemia, overweight, and current smoking, were determined.The prevalence of the major CVRFs, including hypertension, diabetes, dyslipidemia, overweight, and current smoking were 24.3%, 4.3%, 49.3%, 32.0%, and 21.7%, respectively. These risk factors were significantly associated with sex, age, region, ethnicity, and education levels. Overall, 70.3%, 40.3%, and 16.7% of Chinese adults had ≥1, ≥2, or ≥3 CVRFs, respectively. Men, northern and rural residents were more likely to have clustered CVRFs compared with women, southern and urban residents, respectively. Compared with Han residents, Hui and Mongolian residents were more likely, and Tujia and Miao residents were less likely, to have ≥1, ≥2, or ≥3 risk factors. The prevalence of Chinese women having ≥1, ≥2, or ≥3 CVRFs decreased with increasing levels of education.The prevalence and clustering of CVRFs is still high in Chinese adults ≥18 years old, especially in men and in individuals living in the northern and rural areas. Of note, there are differences in cardiovascular risk among different ethnic groups. Therefore, targeted and enhanced intervention measures are required to reduce the risk of cardiovascular disease and the corresponding economic burden of disease in China.

High prevalence of coexisting prehypertension and prediabetes among healthy adults in northern and northeastern China

BackgroundPrehypertension and prediabetes are major risk factors of cardiovascular disease, and their combined presence may result in more serious cardiovascular outcomes than expected with either prehypertension or prediabetes alone. The aim of the present study was to evaluate the prevalence of coexisting prehypertension and prediabetes, and the associated risk profiles in a Chinese population.MethodsA cross-sectional survey in a representative sample of 3,595 men and 4,593 women aged 18 years and older was performed between 2008 and 2010. Prehypertension and prediabetes were diagnosed using the guidelines from the Seventh Report of the Joint National Committee on prevention, detection, and treatment of high blood pressure and American Diabetes Association, respectively. Prehypertension was defined as a systolic blood pressure of 120-139 mmHg and/or diastolic blood pressure of 80-89 mmHg, and prediabetes was defined as a fasting blood glucose of 5.6-6.9 mmol/L.ResultsThe prevalence of coexisting prehypertension and prediabetes was 11.0%. Men had a higher prevalence of coexisting prehypertension and prediabetes than women (14.2% vs. 8.4%; P < 0.0001). This prevalence increased with age and body mass index, and was the lowest among Mongolian-Chinese (5.1%). A multivariate analysis showed that γ-glutamyltransferase and uric acid were significantly and positively correlated with body mass index, waist circumference, blood pressure, triglycerides, and total cholesterol, and negatively correlated with high density lipoprotein cholesterol in subjects with prehypertension and prediabetes.ConclusionsThere is a large proportion of Chinese adults with coexisting prehypertension and prediabetes. Thus, there is a need for more efforts that implement public health programs that target the earlier stages of hypertension and diabetes.

Nationwide Multicenter Reference Interval Study for 28 Common Biochemical Analytes in China

AbstractA nationwide multicenter study was conducted in the China to explore sources of variation of reference values and establish reference intervals for 28 common biochemical analytes, as a part of the International Federation of Clinical Chemistry and Laboratory Medicine, Committee on Reference Intervals and Decision Limits (IFCC/C-RIDL) global study on reference values.A total of 3148 apparently healthy volunteers were recruited in 6 cities covering a wide area in China. Blood samples were tested in 2 central laboratories using Beckman Coulter AU5800 chemistry analyzers. Certified reference materials and value-assigned serum panel were used for standardization of test results. Multiple regression analysis was performed to explore sources of variation. Need for partition of reference intervals was evaluated based on 3-level nested ANOVA. After secondary exclusion using the latent abnormal values exclusion method, reference intervals were derived by a parametric method using the modified Box–Cox formula.Test results of 20 analytes were made traceable to reference measurement procedures. By the ANOVA, significant sex-related and age-related differences were observed in 12 and 12 analytes, respectively. A small regional difference was observed in the results for albumin, glucose, and sodium. Multiple regression analysis revealed BMI-related changes in results of 9 analytes for man and 6 for woman. Reference intervals of 28 analytes were computed with 17 analytes partitioned by sex and/or age.In conclusion, reference intervals of 28 common chemistry analytes applicable to Chinese Han population were established by use of the latest methodology. Reference intervals of 20 analytes traceable to reference measurement procedures can be used as common reference intervals, whereas others can be used as the assay system-specific reference intervals in China.

Strong Negative Interference by Calcium Dobesilate in Sarcosine Oxidase Assays for Serum Creatinine Involving the Trinder Reaction

Abstract The vasoprotective drug calcium dobesilate is known to interfere with creatinine (Cr) quantifications in sarcosine oxidase enzymatic (SOE) assays. The aim of this study was to investigate this interference in 8 different commercially available assays and to determine its clinical significance. In in vitro experiments, interference was evaluated at 3 Cr levels. For this, Cr was quantified by SOE assays in pooled serum supplemented with calcium dobesilate at final concentrations of 0, 2, 4, 8, 16, 32, and 64 &mgr;g/mL. Percent bias was calculated relative to the drug-free specimen. For in vivo analyses, changes in serum concentrations of Cr, cystatin C (CysC; a renal function marker), and calcium dobesilate were monitored in healthy participants of group I before and after oral calcium dobesilate administration. In addition, variations in interference were also examined among different SOE assays using serum obtained from healthy participants of group II. Lastly, Cr levels from the 10 patients treated with calcium dobesilate were measured using 4 SOE assays and liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) for comparison. Our in vitro analyses indicated that the presence of 8 &mgr;g/mL calcium dobesilate resulted in a −4.4% to −36.3% reduction in Cr serum concentration compared to drug-free serum for 8 SOE assays examined. In vivo, Cr values decreased relative to the baseline level with increasing drug concentration, with the lowest Cr levels obtained at 2 or 3 hours after drug administration in participants of group I. The observed Cr concentrations for participants in group II were reduced by −28.5% to −3.1% and −60.5% to −11.6% at 0 and 2 hours after administration related to baseline levels. The Cr values of 10 patients measured by Roche, Beckman, Maker, and Merit Choice SOE assays showed an average deviation of −20.0%, −22.4%, −14.2%, and −29.6%, respectively, compared to values obtained by LC-IDMS/MS. These results revealed a clinically significant negative interference with calcium dobesilate in all sarcosine oxidase-based Cr assays, but the degree of interference varied greatly among the assays examined. Thus, extra care should be taken in evaluating Cr quantification obtained by SOE assays in patients undergoing calcium dobesilate therapy.

A Multicenter Reference Intervals Study for Specific Proteins in China

AbstractA multicenter study conducted in healthy population of 6 cities from the 4 corners and central China for 7 serum-specific proteins to identify the sources of variation and establish the reference intervals on 2 automation platforms.A total of 3148 subjects aged 19 to 64 years old were enrolled in this study to ensure at least 120 participants in each 10-year age group and each city. The majority of samples were transported to central laboratory and measured on both Beckman AU5800 and Immage 800 analytical systems. Three-level nested ANOVA, multiple regression analysis, and the scatter plot were used to explore the variations from sex, age, region, BMI, cigarette smoking, and so on. The latent abnormal value exclusion (LAVE) method was applied at the time of computing RIs as a method for secondary exclusion.Regionality was not observed in any of the immunoassay in China. Variations for sex were significant for IgM among the immune analytes. For CRP and hsCRP results with turbidimetry method (Beckman Coulter AU5800) were lower than the nephelometry method (Beckman Immage). The LAVE method did not affect the RIs computed for the majority of analytes except C4, CRP, and hsCRP. In the scatter plot at the age of 45 years old C3, C4, and IgM reached an inflection point, accordingly RIs were separated by the age group.With the lack of regional differences and the well-standardized status of test results, the RIs of C3, IgG, IgA, IgM derived from this nationwide study can be used for the entire Chinese population. C4, CRP, and hsCRP were affected by different platforms and gender was a significant source of variation for IgM, so they had separated RIs.

A multicenter study on PIVKA reference interval of healthy population and establishment of PIVKA cutoff value for hepatocellular carcinoma diagnosis in China

The aim of this study was to investigate the reference interval of protein‐induced vitamin K absence or antagonist‐II (PIVKA‐II) in China population and to evaluate its medical decision level for hepatocellular carcinoma (HCC) diagnosis.

Establishing reference intervals for sex hormones and SHBG in apparently healthy Chinese adult men based on a multicenter study

Abstract Background: Measuring sex hormones is essential in diagnosing health issues such as testicular dysfunction, male infertility and feminization syndrome. However, there are no reports on reference intervals (RIs) in Chinese men. We conducted a nationwide multicenter study to establish RIs for seven sex hormones (luteinizing hormone [LH], follicle-stimulating hormone [FSH], prolactin [PRL], total testosterone [TT], free testosterone [FT], bioavailable testosterone [BAT] and estrogen [E2]), as well as sex hormone-binding globulin (SHBG). Methods: In 2013, 1043 apparently healthy adult men from five representative cities in China (Beijing, Hangzhou, Guangzhou, Dalian and Urumqi) were recruited; hormones were measured using an automated immunoassay analyzer. Multiple regression analysis (MRA) was performed to identify sources of variation (SVs) that might influence the hormone serum levels. RIs were computed using the parametric method. Results: Dalian and Hangzhou had significantly higher E2 values than other cities; age was a major source of variation for FSH, LH, PRL, SHBG, FT and BAT. FSH, LH and SHBG increased significantly with age, while PRL, FT and BAT decreased with age. TT showed no significant age-related changes. Median (RIs) derived without partition by age were as follows: FSH, 5.6 (1.9–16.3) IU/L; LH, 4.2 (1.6–10.0) IU/L; PRL, 189 (88–450) mIU/L; E2, 85 (4.7–195) pmol/L; SHBG, 29.4 (11.5–66.3) nmol/L; TT, 15.6 (7.4–24.5) nmol/L; FT, 0.31 (0.16–0.52) nmol/L; and BAT, 8.0 (3.7–13.2) nmol/L. RIs were also derived in accordance with between-city and between-age differences. Conclusions: RIs were established for sex hormones and SHBG in apparently healthy Chinese men in consideration of age.

Association between γ-glutamyltransferase and prehypertension

Researchers have identified an association between baseline γ-glutamyltransferase (GGT) and prehypertension. However, data from China are limited. A cross-sectional study was performed among 2,205 subjects from Heilongjiang Province in China. Multiple logistic regression analyses revealed a significant association between baseline GGT and prehypertension [1.59, 95% confidence interval (CI), 1.18–2.16], comparing quartile 4 to quartile 1. Subgroup analyses showed a stronger association between GGT and prehypertension in Koreans; men, current alcohol drinkers and subjects with pre-diabetes. Receiver operating characteristics (ROC) analysis demonstrated that when GGT was higher than 20 U/l, the risk of developing prehypertension increased. Serum GGT is used as a biochemical liver test, but our findings suggest that baseline values may also predict prehypertension in Chinese.