Comorbidity increases the risk of pulmonary tuberculosis: a nested case-control study using multi-source big data.

BACKGROUND: Some medical conditions may increase the risk of developing pulmonary tuberculosis (PTB); however, no systematic study on PTB-associated comorbidities and comorbidity clusters has been undertaken. METHODS: A nested case-control study was conducted from 2013 to 2017 using multi-source big data. We defined cases as patients with incident PTB, and we matched each case with four event-free controls using propensity score matching (PSM). Comorbidities diagnosed prior to PTB were defined with the International Classification of Diseases-10 (ICD-10). The longitudinal relationships between multimorbidity burden and PTB were analyzed using a generalized estimating equation. The associations between PTB and 30 comorbidities were examined using conditional logistic regression, and the comorbidity clusters were identified using network analysis. RESULTS: A total of 4265 cases and 17,060 controls were enrolled during the study period. A total of 849 (19.91%) cases and 1141 (6.69%) controls were multimorbid before the index date. Having 1, 2, and ≥ 3 comorbidities was associated with an increased risk of PTB (aOR 2.85-5.16). Fourteen out of thirty comorbidities were significantly associated with PTB (aOR 1.28-7.27), and the associations differed by sex and age. Network analysis identified three major clusters, mainly in the respiratory, circulatory, and endocrine/metabolic systems, in PTB cases. CONCLUSIONS: Certain comorbidities involving multiple systems may significantly increase the risk of PTB. Enhanced awareness and surveillance of comorbidity are warranted to ensure early prevention and timely control of PTB.

Profile and dynamics of infectious diseases: a population-based observational study using multi-source big data.

BACKGROUND: The current surveillance system only focuses on notifiable infectious diseases in China. The arrival of the big-data era provides us a chance to elaborate on the full spectrum of infectious diseases. METHODS: In this population-based observational study, we used multiple health-related data extracted from the Shandong Multi-Center Healthcare Big Data Platform from January 2013 to June 2017 to estimate the incidence density and describe the epidemiological characteristics and dynamics of various infectious diseases in a population of 3,987,573 individuals in Shandong province, China. RESULTS: In total, 106,289 cases of 130 infectious diseases were diagnosed among the population, with an incidence density (ID) of 694.86 per 100,000 person-years. Besides 73,801 cases of 35 notifiable infectious diseases, 32,488 cases of 95 non-notifiable infectious diseases were identified. The overall ID continuously increased from 364.81 per 100,000 person-years in 2013 to 1071.80 per 100,000 person-years in 2017 (χ2 test for trend, P < 0.0001). Urban areas had a significantly higher ID than rural areas, with a relative risk of 1.25 (95% CI 1.23-1.27). Adolescents aged 10-19 years had the highest ID of varicella, women aged 20-39 years had significantly higher IDs of syphilis and trichomoniasis, and people aged ≥ 60 years had significantly higher IDs of zoster and viral conjunctivitis (all P < 0.05). CONCLUSIONS: Infectious diseases remain a substantial public health problem, and non-notifiable diseases should not be neglected. Multi-source-based big data are beneficial to better understand the profile and dynamics of infectious diseases.

Metabolomics and Lipidomics Profiling in Asymptomatic Severe Intracranial Arterial Stenosis: Results from a Population-Based Study.

No data are available on the serum metabolomics and lipidomics profiles of people with asymptomatic intracranial arterial stenosis. We explored the characteristic metabolites of individuals with asymptomatic severe intracranial arterial stenosis (asICAS) using untargeted serum metabolomics and lipidomics analyses based on ultra-high-performance liquid chromatography high-resolution mass spectrometry (UPLC-HRMS). This case-control study included 25 participants with asICAS and 25 age- and sex-matched controls free of asICAS, who were all diagnosed by using magnetic resonance angiography and derived from the same population-based study. Serum metabolomics and lipidomics profiles were determined using UPLC-HRMS, and possible biomarker metabolites were identified. Compared with the control group, the asICAS group showed higher levels of free choline, glycerophosphocholine, uracil, taurine, and four peptide molecules and lower levels of free fatty acids, hydroxydodecanedioic acid, hydroxy valeryl carnitine, hydroxytetradecanedioic acid, and two sphingomyelin molecules. The serum metabolomics and lipidomics profiles for people with asICAS are characterized by abnormal metabolism of sphingomyelin, taurine/hypotaurine, pyrimidine, and protein (peptide). The biological changes in asICAS may mainly involve taurine/hypotaurine, glycerophospholipid, and sphingolipid metabolism pathways. Biofunctional analysis indicated that these differential metabolites were correlated with metabolic diseases such as early myocardial injury, heart failure, and diabetes.

Lifespan Risk Exposure Measurement Instrument: a Feasible and Effective Tool for Life Course Epidemiology Research.

Life course epidemiology should practically illustrate how risk exposures and their dynamic changes influence the occurrence, development and prognosis of chronic diseases from early life to the elderly. This paper develops the lifespan risk exposure measurement instrument (LREMI) in the framework of retrospective study to collect lifestyle, diet, physical activity information across subjects'life courses from 18-years-old to current age. Through a pilot study, the result of the test-retest analysis demonstrated the reliability of LREMI. In Shandong Multicenter Cohort, the LREMI showed its feasibility, for it could measure the exposure spectrum on both individuals and population with different life experiences. Moreover, it had good differentiation ability for identifying cases versus controls in population-based case-control study. However, further studies should be conducted in an already available prospective cohort to ascertain that our results could match prospective data.

[Analysis of infrared spectra of 60 kinds of plant extract of traditional Chinese medicine and study on the identification and evaluation of characteristics of the regional markers associated with cold and heat nature].

By using the Fourier transform infrared spectroscopy and linear discriminant analysis (LDA), logistic discriminant analysis (Logistic-DA), principal component analysis-linear discriminant analysis (PCA-LDA), partial least-squares discriminant analysis (PLS-DA), random forest (RF), support vector machine (SVM), infrared spectra of 60 kinds of plant extract of Chinese traditional medicine were analyzed and the identification and evaluation of characteristics of the regional markers associated with cold and heat nature were studied. Results indicated that LDA and SVM are suitable for the recognition model of water extract infrared spectral data, LDA is suitable for the identification model of anhydrous ethanol extract infrared spectral data, SVM is suitable for the identification model of chloroform extract infrared spectral data, while petroleum ether extract group recognition effect is not ideal. According to the suitable characteristic parameters identification model, data were analyzed by infrared spectroscopy, and parameters and resistance characteristics of the traditional Chinese drug composition can be obtained. Regional characteristics of these two parameters can be used to identify drug ingredients, and can also be used to indicate different degrees of resistance characteristics of traditional Chinese medicine. Component parameter is model identification coefficient corresponding to the position of spectrum and infrared, with a value greater than zero it is cold nature marker, while with a value less than zero it is heat nature marker; model identification score is a parameter reflecting the degree of cold and heat nature, the greater the score (positive), the more it is cold, while the smaller the score, the more it is hot. a parameter reflecting the degree of cold and heat,the greater the score (positive) is cold more strong, the score is small (negative) heat stronger.

Spatio-temporal evolution on geographic boundaries of HFRS endemic areas in Shandong Province, China.

OBJECTIVE: To take effective strategies and measures for the prevention and control of hemorrhagic fever with renal syndrome (HFRS) endemic areas by investigating its dynamic geographical boundaries in Shandong Province, China. METHODS: The incidence of HFRS from 1982 to 2008 in Shandong Prvince, China, was detected with inverse distance weighting (IDW) interpolation based on geographical information system (GIS). Dynamic geographical boundaries of HFRS endemic areas in Shandong Province, China, were analyzed by geographical boundary analysis. RESULTS: The HTN-type endemic areas of HFRS were located in Linyi City in phase 1 (1982-1986), the SEO-type endemic areas of HFRS were located in Jining City in phase 2 (1987-2003), and the endemic areas of HFRS in Jining City gradually disappeared and the endemic areas of HFRS with mixed-types of reservoir rodents were located in Linyi City in phase 3 (2004-2008). Meanwhile, new endemic areas emerged in the northwestern Shandong province, China. CONCLUSION: The SEO-type endemic areas of HFRS are located in western Shandong Province, China, and the HTN-type endemic areas of HFRS are located eastern Shandong Province, Chin, indicating that the endemic areas of HFRS should be vaccinated and rodents should be controlled.

[Path analysis of lifestyle habits to the metabolic syndrome].

OBJECTIVE: To evaluate the relationship between lifestyle habits and the components of metabolic syndrome (MS). METHODS: Based on the routine health check-up system in a certain Center for Health Management of Shandong Province, a longitudinal surveillance health check-up cohort from 2005 to 2010 was set up. There were 13 225 urban workers in Jinan included in the analysis. The content of the survey included demographic information, medical history, lifestyle habits, body mass index (BMI) and the level of blood pressure, fasting blood-glucose, and blood lipid, etc. The distribution of BMI, blood pressure, fasting blood-glucose, blood lipid and lifestyle habits between MS patients and non-MS population was compared, latent variables were extracted by exploratory factor analysis to determine the structure model, and then a partial least squares path model was constructed between lifestyle habits and the components of MS. RESULTS: Participants'age was (46.62 ± 12.16) years old. The overall prevalence of the MS was 22.43% (2967/13 225), 26.49% (2535/9570) in males and 11.82% (432/3655) in females. The prevalence of the MS was statistically different between males and females (χ(2) = 327.08, P < 0.01). Between MS patients and non-MS population, the difference of dietary habits was statistically significant (χ(2) = 166.31, P < 0.01) in MS patients, the rate of vegetarian, mixed and animal food was 23.39% (694/2967), 42.50% (1261/2967) and 34.11% (1012/2967) respectively, while in non-MS population was 30.80% (3159/10 258), 46.37% (4757/10 258), 22.83% (2342/10 258) respectively. Their alcohol consumption has statistical difference (χ(2) = 374.22, P < 0.01) in MS patients, the rate of never or past, occasional and regular drinking was 27.37% (812/2967), 24.71% (733/2967), 47.93% (1422/2967) respectively, and in non-MS population was 39.60% (4062/10 258), 31.36% (3217/10 258), 29.04% (2979/10 258) respectively. The difference of their smoking status was statistically significant (χ(2) = 115.86, P < 0.01) in MS patients, the rate of never or past, occasional and regular smoking was 59.72% (1772/2967), 6.24% (185/2967), 34.04% (1010/2967) respectively, while in non-MS population was 70.03% (7184/10 258), 5.35% (549/10 258), 24.61% (2525/10 258) respectively. Both lifestyle habits and the components of MS were attributable to only one latent variable. After adjustment for age and gender, the path coefficient between the latent component of lifestyle habits and the latent component of MS was 0.22 with statistical significance (t = 6.46, P < 0.01) through bootstrap test. Reliability and validity of the model:the lifestyle latent variable: average variance extracted was 0.53, composite reliability was 0.77 and Cronbach's a was 0.57. The MS latent variable: average variance extracted was 0.45, composite reliability was 0.76 and Cronbach's a was 0.59. CONCLUSION: Unhealthy lifestyle habits are closely related to MS. Meat diet, excessive drinking and smoking are risk factors for MS.

[Pattern recognition for traditional Chinese medicine nature of 60 kinds of herbal medicine based on high performance capillary electrophoresis fingerprint].

OBJECTIVE: To establish signature pattern recognition model of cold-hot nature of herbal medicine. METHODS: High performance capillary electrophoresis fingerprints of 60 kinds of herbal medicine (30 kinds of cold, 30 of hot) were established, features of wavelength were screened, 6 analysis methods such as linear discriminant analysis (LDA), logistic discriminant analysis (Logistic-DA), principal component and linear discriminant analysis (PCA-LDA), partial least-squares discriminant analysis (PLS-DA), random forest (RF) and support vector machine (SVM) were used to establish and evaluate recognition model of cold-hot nature after data processing. RESULTS: SVM was proved to be a suitable means of recognition model of herbal medicine cold-hot nature based on data of HPCE fingerprints. Characteristic parameters of nature could be screened according to theoretical spectra signature of nature model, the characteristic regions of components of herbs with cold-heat nature could be identified in the HPCE fingerprint. The characteristic parameters of cold-hot nature were the identifying coefficient for specific retention time of the theoretical spectra of recognition model, identification coefficients greater than zero were for the cold marker, while that less than zero for the hot marker. CONCLUSION: The results imply that HPCE is a feasible and effective means for identification of cold-hot nature of Traditional Chinese medicine.

[Genetic polymorphisms of 15 X-STR loci in Shandong Han population].

OBJECTIVE: To investigate the genetic polymorphisms of 15 X-STR loci in Shandong Han population in order to establish the forensic application database. METHODS: The multi-PCR primers of these loci were designed by Primer Premier 5.0 software and labeled by 4 fluoresceins (FAM, VIC, NED and TET). The developed multi-PCR was used to investigate 15 X-STR loci (DXS10011, DXS101, GATA 165B12, DXS6795, DXS6800, DXS6801, DXS6803, DXS7132, DXS7133, DXS7423, DXS7424, DXS8377, DXS8378, DXS9898 and HPRTB) selected from the X chromosome of 481 unrelated individuals (295 females and 186 males) in Shandong Han population. RESULTS: Among the 15 X-STR loci, GATA 165B12, DXS6800, DXS6803, DXS7133 and DXS7423 showed moderate polymorphisms, while the rest 10 X-STR loci showed high polymorphisms (PIC > 0.5 and H > 0.5). No shared haplotype was detected among the males in Shandong Han population. CONCLUSION: The developed multi-PCR system with fluorescence detection provides an effective way to establish X-STR loci database of population genetics in Shandong Han population and shows its forensic application.

Associations of air pollutants with pneumonia hospital admissions in Qingdao, China: a prospective cohort study.

Studies about the pneumonia morbidity effects of various air pollution exposure are still limited in China. We aimed to explore the short-term effect of air pollutants exposure on pneumonia admission and identify the vulnerable groups in Qingdao, China. From January 2015 to October 2017, a prospective cohort involving 433,032 participants across 3 counties in Qingdao were enrolled in the study. Distributed lag nonlinear model (DLNM) was applied to assess the associations between air pollutants and pneumonia hospitalizations. There were 636 cases of pneumonia, with an annual incidence density of 54.33 per 100,000 person-years (95% CI: 50.11, 58.56). A 10 µg/m3 increment of sulfur dioxide (SO2) distributed at a 4-week lag in Qingdao was associated with increased pneumonia hospitalizations, with a risk ratio of 2.10 (95% CI: 1.06, 4.13). Subgroup analyses indicate that PM ≤ 2.5 µm in aerodynamic diameter and SO2 showed stronger effects on pneumonia in females than males, whereas people in urban regions were more vulnerable to nitrogen dioxide and ozone (O3) than the others. We also observed distinct acute effects and harvesting effects of SO2 and O3 on pneumonia in urban areas. Strategies should be taken to further reduce levels of ambient PM2.5, SO2, and O3.

Incidence trend and disease burden of seven vaccine-preventable diseases in Shandong province, China, 2013-2017: Findings from a population-based observational study.

INTRODUCTION: Although vaccines provide a cost-effective solution to vaccine-preventable diseases (VPDs), the disease burden of VPDs is still very high in most parts of the world. METHODS: A population-based observational study was conducted in Shandong province, China, from 2013 to 2017, giving an insight into the epidemiological characteristics and disease burden of seven VPDs. The incidence trend was estimated using the Poisson regression model. The disease burden was calculated using the disability-adjusted life years (DALYs). RESULTS: Most VPDs included in the China's National Immunization Program had higher incidence density (ID) in inland cities. The ID of mumps decreased significantly, while herpes zoster increased (both P < 0.05). The top three causes of the disease burden as assessed with DALYs included tuberculosis, herpes zoster, and hepatitis B, with the rates of 72.21, 59.99, and 52.10 DALYs/100 000, respectively. The disease burden of influenza and herpes zoster were relatively high in people aged > 50 years, while highest DALYs of hepatitis B were found in young adults. CONCLUSION: Inequalities in the vaccine coverage by geography, socio-economic status, and targeted population contribute to the increasing incidence and high burden of VPDs and call for renewed and sustained immunization strategies in China.

[Association study between TNFSF4 and coronary heart disease].

Previous studies suggest that TNFSF4 is a susceptibility gene of atherosclerosis. But case-control association analysis in Swedish population and German population provided inconsistent, even opposite results. In order to explore the relationship between this gene and coronary heart disease (CHD) in Chinese Han population, we collected 498 cases and 509 controls from Qilu hospital of Shandong University and analyzed the association between five single-nucleotide polymorphisms (SNPs) (rs1234314, rs45454293, rs3850641, rs1234313, and rs3861950) of TNFSF4 and CHD. On the basis of using traditional statistical analysis methods based on single SNP and haplotypes, we introduced principal component score-based logistic regression analysis to deal with the data. The results suggested that in Armitage trend test, only rs3861950 was significant, when used the Bonferroni correction, and all of the five SNPs were not statistically significant. In the logistic regression analysis which adjusts the confounding factors, all of the five SNPs were not statistically significant. In haplotype analysis, the frequencies of six haplotypes were significantly different in cases and controls (CTAGT (P=0.0006), CTAAC (P=0.0123), CCAGT (P=0.0004), GTGGT (P=0.0329), GCGAC (P<0.0001), and GCAAC (P=0.0173)). In principal component score-based logistic regression analysis, the first principal component has statistical significance (P=0.0236). These results indicate that TNFSF4 is a susceptibility gene of CHD in Chinese Han population.

Infectious diseases among elderly persons: Results from a population-based observational study in Shandong province, China, 2013-2017.

BACKGROUND: The health of the elderly is one of the major challenges in today's ageing society. However, research on infectious diseases among the elderly is limited. This study aimed to describe the epidemiological characteristics and dynamics of infectious diseases among the elderly population aged ≥60 years in Shandong province, China. METHODS: Incidence data for infectious diseases were collected from the Shandong Multi-Center Healthcare Big Data Platform from January 2013 to June 2017, which involved 550 432 elderly persons. We compared the incidence of each infectious disease and disease category, stratified by age, gender, and region. Annual percentage change (APC) was estimated using logarithmic linear regression to examine the incidence trends. Poisson regression was conducted to identify the effect of demographic factors on incidence, with incidence rate ratio (IRR) and their 95% confidence intervals (CIs) estimated. RESULTS: A total of 27 595 cases of 102 infectious diseases were reported during the study period, with an overall incidence of 1425.51/100 000 person-years. The most common infectious diseases were respiratory and mucocutaneous diseases among the elderly persons, with annual increases of 17.45% and 20.44%, respectively (both P<0.05). In rural areas, the incidence of respiratory, gastrointestinal, blood- and sex-transmitted, and mucocutaneous infections increased significantly, with APCs of 178.52%, 204.66%, 28.24%, 63.01%, respectively (all P<0.05). Elderly males had a higher risk of infections than that of females, with the highest IRRa of 2.94 (95% confidence interval (CI) = 2.89, 3.00) in respiratory diseases. The elderly aged 85-89 years had a much higher risk of respiratory diseases than those aged 60-64 years (IRRa = 9.85, 95%CI: 9.39, 10.33); however, the risk of blood- and sex-transmitted diseases was highest among the elderly aged 65-69 years (IRRa = 1.24, 95% CI = 1.06, 1.45). CONCLUSIONS: Ageing population are facing a substantial challenge on infectious diseases. More attention should be paid to infections with significant growth. Targeted strategies and measures on elderly persons in different regions and subgroups are urgently needed.

Apolipoprotein E Facilitates Amyloid-ß Oligomer-Induced Tau Phosphorylation.

Hyperphosphorylated tau is one of the key characteristics of Alzheimer's disease (AD), and tau pathology correlates with cognitive impairment in AD better than amyloid-ß (Aß) pathology. Thus, a complete understanding of the relevant factors involved in tau phosphorylation is important for AD treatment. APOEɛ4, the strongest genetic risk factor for AD, was found to be involved in tau pathology in frontotemporal dementia. This result indicated that apolipoprotein E (ApoE) may also participate in tau phosphorylation in AD. In the present study, we injected Aß oligomer (AßO) into the lateral ventricles of wild-type (WT) mice and apoE-/- mice to test the process of tau phosphorylation in the acute phase. We found that the phosphorylated tau and phosphokinase levels were higher in WT mice than in apoE-/- mice. These phenomena were also confirmed in vitro. ApoE ɛ4-treated apoE-/- neurons exhibited more phosphorylated tau than ApoE ɛ2- and ApoE ɛ3-treated neurons. We also found that AßO induced more serious inflammation in WT mice and in ApoE-positive cultured neurons. Anti-inflammatory treatment reduced the phosphorylated tau level induced by AßOs in ApoE-positive neurons. These results suggest that ApoE may facilitate the phosphorylation of tau induced by AßO via inflammation.

Epidemic and control of COVID-19 in Niger: quantitative analyses in a least developed country.

BACKGROUND: The COVID-19 pandemic is challenging the public health response system worldwide, especially in poverty-stricken, war-torn, and least developed countries (LDCs). METHODS: We characterized the epidemiological features and spread dynamics of COVID-19 in Niger, quantified the effective reproduction number (Rt ), evaluated the impact of public health control measures, and estimated the disease burden. RESULTS: As of 4 July 2020, COVID-19 has affected 29 communes of Niger with 1093 confirmed cases, among whom 741 (67.8%) were males. Of them 89 cases died, resulting in a case fatality rate (CFR) of 8.1%. Both attack rates and CFRs were increased with age (P < 0.0001). Health care workers accounted for 12.8% cases. Among the reported cases, 39.3% were isolated and treated at home, and 42.3% were asymptomatic. 74.6% cases were clustered in Niamey, the capital of Niger. The Rt fluctuated in correlation to control measures at different outbreak stages. After the authorities initiated the national response and implemented the strictest control measures, Rt quickly dropped to below the epidemic threshold (<1), and maintained low level afterward. The national disability-adjusted life years attributable to COVID-19 was 1267.38 years in total, of which years of life lost accounted for over 99.1%. CONCLUSIONS: Classic public health control measures such as prohibition of public gatherings, travelling ban, contact tracing, and isolation and quarantine at home, are proved to be effective to contain the outbreak in Niger, and provide guidance for controlling the ongoing COVID-19 pandemic in LDCs.

Impacts of transportation and meteorological factors on the transmission of COVID-19.

The ongoing pandemic of 2019 novel coronavirus disease (COVID-19) is challenging global public health response system. We aim to identify the risk factors for the transmission of COVID-19 using data on mainland China. We estimated attack rate (AR) at county level. Logistic regression was used to explore the role of transportation in the nationwide spread. Generalized additive model and stratified linear mixed-effects model were developed to identify the effects of multiple meteorological factors on local transmission. The ARs in affected counties ranged from 0.6 to 9750.4 per million persons, with a median of 8.8. The counties being intersected by railways, freeways, national highways or having airports had significantly higher risk for COVID-19 with adjusted odds ratios (ORs) of 1.40 (p = 0.001), 2.07 (p < 0.001), 1.31 (p = 0.04), and 1.70 (p < 0.001), respectively. The higher AR of COVID-19 was significantly associated with lower average temperature, moderate cumulative precipitation and higher wind speed. Significant pairwise interactions were found among above three meteorological factors with higher risk of COVID-19 under low temperature and moderate precipitation. Warm areas can also be in higher risk of the disease with the increasing wind speed. In conclusion, transportation and meteorological factors may play important roles in the transmission of COVID-19 in mainland China, and could be integrated in consideration by public health alarm systems to better prevent the disease.

Association between serum γ-glutamyltransferase and chronic kidney disease in urban Han Chinese: a prospective cohort study.

PURPOSE: Limited numbers of literatures have focused on the association between γ-glutamyltransferase (GGT) and chronic kidney disease (CKD), and their results were controversial. Therefore, in this study, we set up a large-scale cohort of Chinese population to discover and verify the association between serum GGT and CKD. METHODS: Our cohort study was based on 21,818 patients who visited Health Management Center of Shandong Provincial Hospital, China, to receive routine health check-up during the period of 2005-2010, and we used multivariate Cox regression model to clarify whether elevated serum GGT increased the risk of CKD or not. RESULTS: During the follow-up of 57,891 person-years, 1456 patients developed CKD, giving rise to an incidence density of 25.15 per 1000 person-years (1456/57,891 person-years). After adjusting gender, age, baseline serum creatinine (SCr), body mass index (BMI), serum albumin (ALB), alanine aminotransferase (ALT), hemoglobin, white blood cell count (WBC), triglyceride (TG), total cholesterol (TC), hypertension, cardiovascular disease (CVD), diabetes, smoking and drinking status, the risk for CKD increased with the elevated serum GGT quartiles. The hazard ratio (HR) for CKD was 1.326 (95 % confidence interval (CI), 1.073-1.639) when the top quartile of serum GGT was compared with the bottom one, and the HR of log-transformed serum GGT for CKD was 1.658 (95 % CI, 1.294-2.125). The results were consistent in males but different in females when gender was stratified. CONCLUSION: The result reveals that there is a positive relationship between increasing serum GGT levels and the incidence of CKD which suggests that elevated GGT level could be a potential indicator for risk of CKD.

Spatial genetic structure of two HIV-I-resistant polymorphisms (CCR2-64 I and SDF1-3'A) alleles in population of Shandong Province, China.

OBJECTIVE: To explore the spatial genetic structure of two HIV-I-resistant polymorphisms (CCR2-64 I and SDF1-3'A) alleles in the population of Shandong Province, China. METHODS: Using the techniques of spatial stratified sampling and spatial statistics, the spatial genetic structure of the locus (CCR2-64 I and SDF1-3'A), which was shown to be important co-receptor for HIV infection, was quantified from the populations of 36 sampled counties of Shandong Province, and a total of 3147 and 3172 samples were taken for testing CCR2-64I and SDF1-3'A respectively from individuals without known history of HIV-I infection and AIDS symptoms. RESULTS: There were significantly spatial genetic structures of the two alleles at different spatial distance classes on the scale of populations, but on the scale of individuals, no spatial structure was found in either the whole area of Shandong Province or the area of each sampled county. Although the change of frequencies of the two alleles with geographic locations in Shandong Province both showed gradual increase trends, their changing directions were inverse. The frequency of CCR2-64I allele gradually increased from the southwest to the northeast, while the frequency of SDF1-3'A allele gradually increased from the northeast to the southwest. However the RH to AIDS of combined types of their different genotypes did not represent obvious geographic diversity on the whole area of the Province. CONCLUSION: The frequency of allele usually has some spatial genetic structures or spatial autocorrelation with different spatial distance classes, but the genotypes of individuals have random distribution in the same geographic area. Evaluating spatial distribution of the genetic susceptibility of HIV (AIDS) to CCR2-64I and SDF1-3'A alleles, should focus on the frequencies of combined genotypes of CCR2 and SDF1 based on the two-locus genotypes of each individual rather than the frequencies of CCR2-64I and SDF1-3'A alleles.

The "Kriging" model of spatial genetic structure in human population genetics.

This paper presents the application of Kriging technique in the field of human population genetics for quantifying the spatial genetic heterogeneity of HLA-A locus in the area of China,and for mapping its spatial genetic structure using the measurement of synthetic genetic structure (SPC) and the principal components (PC). Both principles of the method and the basic equations are given. The Kriging model has several advantages over other interpolation and smoothing methods. Firstly, it relies on the structure of the spatial genetic semivariogram model, which can be used to quantify the spatial genetic heterogeneity of the locus (loci) before mapping its spatial genetic structure. Secondly, it is virtually unbiased in the interpolation situation,where the location to be estimated is surrounded by data on all sides and is influenced within the range of these data. Thirdly, it allows of estimative error of interpolation, which can be used to appraise the predicting effect for the spatial estimation,and the error maps can be used to decide where to introduce new sampling population genetic data. However, the "Kriging" model also has some disadvantages. Firstly,when the theoretical spatial genetic semivariogram can not be fitted by any models, the "Kriging" model can not be set up. Secondly, if the Kriging model was built by a poor spatial genetic semivariogram,the Kriging estimation standard deviation is remarkably high in the whole area, hence the Kriging model can not be suitable to estimating the distribution of spatial genetic structure. In these situations,the interpolation algorithm, whose assumption is spatial random rather than spatial autocorrelation,such as the Cavalli-Sforza method in Genography, inverse distance-weighted methods, splines, should be used to estimate or map the distribution of spatial genetic structure.