Association of APOE Genotype with Bone Mineral Density in Men and Women: The Dong-gu and Namwon Studies / 전남의대학술지

Many studies have investigated relationships between APOE genotype and bone mineral density (BMD). However, the results of these studies have been inconsistent. Few studies have been carried out in Asian populations. We studied the relationship of the APOE gene polymorphism and BMD in two large population-based studies. The datasets included the Dong-gu Study (3575 men and 5335 women) and the Namwon Study (2310 men, 3512 women). Lumbar spine and femoral neck BMD were measured by dual-energy X-ray absorptiometry. APOE genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. The APOE genotypes were classified into APOE E2 (E2/E2 and E2/E3), APOE E3 (E3/E3), and APOE E4 (E3/E4 and E4/E4). The genotype distribution of the study population was in Hardy-Weinberg equilibrium. There were no significant differences among APOE genotype groups in lumbar and femoral neck BMD in either cohort. Our data do not support the hypothesis that the APOE genotype is associated with BMD.

Association of APOE Genotype with Bone Mineral Density in Men and Women: The Dong-gu and Namwon Studies / 전남의대학술지

Many studies have investigated relationships between APOE genotype and bone mineral density (BMD). However, the results of these studies have been inconsistent. Few studies have been carried out in Asian populations. We studied the relationship of the APOE gene polymorphism and BMD in two large population-based studies. The datasets included the Dong-gu Study (3575 men and 5335 women) and the Namwon Study (2310 men, 3512 women). Lumbar spine and femoral neck BMD were measured by dual-energy X-ray absorptiometry. APOE genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. The APOE genotypes were classified into APOE E2 (E2/E2 and E2/E3), APOE E3 (E3/E3), and APOE E4 (E3/E4 and E4/E4). The genotype distribution of the study population was in Hardy-Weinberg equilibrium. There were no significant differences among APOE genotype groups in lumbar and femoral neck BMD in either cohort. Our data do not support the hypothesis that the APOE genotype is associated with BMD.

Association between Apolipoprotein E Polymorphism and Chronic Kidney Disease in the Korean General Population: Dong-gu Study / 가정의학회지

BACKGROUND: Few studies have investigated the association between Apolipoprotein E (APOE) polymorphisms and chronic kidney disease (CKD) in the general population, and their results are inconsistent. METHODS: The current study population was composed of 9,033 subjects aged > or = 50 years who participated in the baseline survey of the Dong-gu Study, which was conducted in Korea between 2007 and 2010. APOE polymorphisms were identified by polymerase chain reaction, and the estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease equation. RESULTS: Individuals with the APOE E2 allele had significantly lower total and low density lipoprotein cholesterol levels, those with the APOE E4 allele had lower high density lipoprotein (HDL) cholesterol levels, and those with the APOE E3 allele had lower log-triglyceride levels. Adjusting for covariates (sex, age, body mass index, smoking, systolic blood pressure, hypertension, diabetes, total cholesterol, HDL cholesterol, log-transformed triglycerides, and log-transformed albumin to creatinine ratio), mean eGFR was not significantly different among APOE alleles (E2, 69.4 mL/min/1.73 m2; E3, 69.5 mL/min/1.73 m2; E4, 69.4 ml/min/1.73 m2; P = 0.873). Additionally, the odds ratios (ORs) indicated that APOE polymorphisms were not independent risk factors for CKD (OR, 1.07; 95% confidence interval [CI], 0.91 to 1.26 for the E2 vs. E3 allele; OR, 1.01; 95% CI, 0.88 to 1.16 for the E4 vs. E3 allele). CONCLUSION: APOE polymorphisms were not associated with either eGFR or CKD in the general Korean population.

High Prevalence of Vitamin D Deficiency in Adults Aged 50 Years and Older in Gwangju, Korea: the Dong-gu Study

Vitamin D plays an important role in bone metabolism and maintaining bone health. Recently, new evidence has revealed that vitamin D affects chronic diseases such as autoimmune diseases, cardiovascular diseases and certain cancers. The aim of this study was to evaluate the vitamin D status and the prevalence of vitamin D deficiency in an urban Korean population. This study included 8,976 participants (3,587 men and 5,389 women) aged 50 yr and older. Serum 25(OH)D level was measured by chemiluminescent microparticle immunoassay. The prevalence of vitamin D deficiency [25(OH)D < 20 ng/mL] was 59.7% and 86.5% in men and women, respectively. The prevalence of vitamin D deficiency increased significantly with age in men, but not in women and it decreased from April to July, more prominently in men than in women. These results suggest that sun exposure, intake of vitamin D supplement, and regular physical activities is recommended in an urban Koreans, especially in women.

Association between Methylenetetrahydrofolate Reductase C677T Polymorphism and Bone Mineral Density: The Dong-gu Study and the Namwon Study

The purpose of this study was to examine the association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and bone mineral density (BMD). Two large cohort studies were performed: the Dong-gu Study (3,621 men and 5,409 women) and the Namwon Study (3,703 men and 5,672 women). We assessed lumbar spine and femoral neck BMD by dual-energy X-ray absorptiometry. Genotypes were determined by real-time polymerase chain reaction. Multiple linear regression analysis was performed to evaluate the association between MTHFR C677T and BMD, adjusting for age, weight and height. The MTHFR C677T genotype frequencies for CC, CT, and TT genotypes were 34.5, 48.7, and 16.8%, respectively, in the Dong-gu Study and 33.6, 49.2, and 17.2%, respectively, in the Namwon Study. There are no significant differences between the MTHFR C677T genotype and the BMD at the lumbar spine and femoral neck in men or women in both cohorts.

Association between Total Bilirubin and Hemoglobin A1c in Korean Type 2 Diabetic Patients

Recent studies have shown that bilirubin is negatively associated with hemoglobin A1c (HbA1c) in the general population. The association between bilirubin and HbA1c in serum of diabetes patients has not yet been studied. The aim of the present study was to evaluate the association between total bilirubin and HbA1c in Korean patients with type 2 diabetes. A total of 690 of the 1,275 type 2 diabetes patients registered with the public health centers in Seo-gu, Gwangju and Gokseong-gun, Jeollanam-do participated in this study. Following an overnight fast, venous blood and urine samples were collected and analyzed. The mean HbA1c values differed significantly according to total bilirubin ( or = 0.8 mg/dL, 7.1%; P for trend = 0.016) after we adjusted for other confounding factors. When the odds ratio (OR) was adjusted for other confounding factors, there was a significant association between total bilirubin and HbA1c (OR, 0.4 [95% confidence interval, 0.2-0.8] for total bilirubin > or = 0.8 mg/dL versus < or = 0.4 mg/dL. In conclusion, total bilirubin concentrations in serum are negatively associated with HbA1c levels after adjustment for sex, age, and other confounding factors in type 2 diabetes patients.

Complete Sequencing of the ABO Alleles of the Common ABO Group and Rare ABO Subgroups in Koreans / 대한수혈학회지

BACKGROUND: Complete sequencing, except for intron 1, of the ABO allele in some populations has been reported. However, so far, one report on complete sequencing of the ABO gene in three Korean families with normal ABO phenotypes has been published. This study aimed to establish a reference database of common ABO alleles in Koreans. METHODS: Screening of common ABO alleles, including homozygote form, was performed by direct sequencing of exons 6 and 7 and by real-time PCR using displacing probes in 95 healthy donors. Genomic DNA from the common ABO group (n=8) and some ABO subgroups (n=7) was used in complete sequencing (except for intron 1) of the ABO allele. RESULTS: The sequences of B101/B101 (n=1), O01/O01 (n=1) were identical with the corresponding sequences registered in Genebank. A102 and A105 had a common point mutation, 1142 C>T in intron 4. A102 (n=3/11) and O02 (n=3/3), selected by sequencing of exons 6 and 7, were reclassified into A105 and O65 by whole genomic sequencing, respectively. Analytic results for ABO subgroups were as follows: B3, B101/O01 (n=3) and B101/O02 (n=1); A1B3, A102/B101 (n=1) and A105/B101 (n=1); Ax, A102/O01 (n=1). CONCLUSION: We established a reference database of common ABO alleles in Koreans and found that the molecular basis of introns of ABO alleles in the Korean population differs from that reported in previous studies of other populations.

Application of Real-Time PCR for ABO Genotyping for Large-scale Population Screening / 대한수혈학회지

BACKGROUND: For large-scale population screening, the method of ABO genotyping needs to be simple, accurate and cost-effective. The real-time PCR method has been introduced and it is suitable for dealing with large numbers of specimens. In this study, we examined the ABO genotyping of 1,700 residents of Jeollanam-do for an epidemiologic study by applying the real-time PCR method. METHODS: Genomic DNA was extracted from the peripheral blood samples of 1,700 residents of Jeollanam-do between July 2004 and January 2006 and these samples were stored at -70degrees C. The ABO genotype in all the samples was determined by four-color real-time PCR using displacing probes and three cases that had an atypical real time PCR pattern were confirmed by direct sequencing and PCR-based cloning of exons 6&7 of the ABO gene. RESULTS: The genotyping results of 1,700 samples included O/O (25.6%), A/A (9.1%), A/O (29.1%), B/B (4.5%), B/O (19.8%) and A/B (11.9%), and the allele frequencies of O, A and B were 50.1%, 29.5% and 20.4%, respectively. The frequency of the O allele was lower in the residents of Jeollanam-do than that previously reported for the residents of Kangwon-do (P=0.014), while the frequency of the A allele was higher in the residents of Jeollanam-do than that previously reported for the residents of Kangwon-do (P=0.003). The three cases with atypical results were revealed to be B101/O24, Bvar(296C>T)/O01 and B101/Ovar(801G>T). It takes 6 days to perform ABO genotyping on 1,700 samples by a calculation per test. CONCLUSION: ABO genotyping by real-time PCR using displacing probes can be useful for mass screening for ABO genotyping. In Korea, the frequency of the ABO allele was significantly different among different regions.