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Biomedical subjects

T Y Tai

Publications and source records attributed to T Y Tai.

At least 55 records · Page 3Linked to original sources
PubMed1996

Dose-response relationship between ischemic heart disease mortality and long-term arsenic exposure.

The cardiovascular effects of inorganic arsenic have been documented, but the dose-response relationship between ischemic heart disease (ISHD) and long-term arsenic exposure remains to be elucidated. Mortality rates from ISHD among residents in 60 villages of the area in Taiwan with endemic arseniasis from 1973 through 1986 were analyzed to examine their association with arsenic concentration in drinking water. Based on 1 355 915 person-years and 217 ISHD deaths, the cumulative ISHD mortalities from birth to age 79 years were 3.4%, 3.5%, 4.7%, and 6.6%, respectively, for residents who lived in villages in which the median arsenic concentrations in drinking water were <0.1, 0.1 to 0.34, 0.35 to 0.59, and > or = 0.6 mg/L. A cohort of 263 patients affected with blackfoot disease (BFD), a unique arsenic-related peripheral vascular disease, and 2293 non-BFD residents in the endemic area of arseniasis were recruited and followed up for an average period of 5.0 years. There was a monotonous biological gradient relationship between cumulative arsenic exposure through drinking artesian well water and ISHD mortality. The relative risks were 2.5, 4.0 and 6.5, respectively, for those who had a cumulative arsenic exposure of 0.1 to 9.9, 10.0 to 19.9, and > or = 20.0 mg/L-years compared with those without the arsenic exposure after adjustment for age, sex, cigarette smoking, body mass index, serum cholesterol and triglyceride levels, and disease status for hypertension and diabetes through proportional-hazards regression analysis. BFD patients were found to have a significantly higher ISHD mortality that non-BFD residents, showing a multivariate-adjusted relative risk of 2.5 (95% CI, 1.1 to 5.4).

Adolescent↗
PubMed1996

No association between the Gly971Arg variant of the insulin receptor substrate 1 gene and NIDDM in the Taiwanese population.

OBJECTIVE: To study the role of the Gly971Arg variant of the insulin receptor substrate 1 (IRS-1) gene in the development of NIDDM in the Chinese population living in Taiwan. RESEARCH DESIGN AND METHODS: A total of 82 unrelated normal control subjects, 89 subjects with NIDDM, and 23 multiplex families were recruited in Taiwan. All of them were Han Chinese. Pedigree members without a history of diabetes were studies by the standard 75-g oral glucose tolerance test. Detection of the Gly971Arg variant of the IRS-1 gene was performed by polymerase chain reaction and restriction fragment-length polymorphism analysis. RESULTS: The frequency of Gly971Arg variant of the IRS-1 gene in the normal population was 1.2% which was lower than frequencies reported in white populations. The prevalence of the Gly971Arg variant was not significantly increased in both the nonselected NIDDM population (1.1%) and the probands of the multiplex families (4.3%). More importantly, the Gly971Arg variant of the IRS-1 gene did not cosegregate with BMI and NIDDM in these families, CONCLUSIONS: The Gly971Arg variant of the IRS-1 gene is an infrequent normal allele among Taiwanese. This variant is neither associated nor cosegregated with NIDDM in the Taiwanese population and families. Gly971Arg of IRS-1 gene does not play an important role in the development of NIDDM in this population.

Adult↗
PubMed1995

CA-repeated microsatellite polymorphism of the glucokinase gene and its association with non-insulin-dependent diabetes mellitus in Taiwanese.

Mutation of the glucokinase gene has recently been identified as a cause of maturity-onset diabetes of the young (MODY), a subset of non-insulin-dependent diabetes mellitus (NIDDM). However, its role in the wide variety of NIDDM remains controversial due to conflicting reports of association studies, negative results of linkage studies and low prevalence of glucokinase mutations in the common variety of NIDDM. In this study, two (CA)n-microsatellite polymorphisms flanking both ends of the glucokinase gene, termed GCK1 and GCK2, were used to evaluate the role of glucokinase on NIDDM susceptibility of Taiwanese. For GCK1, three alleles (Z,Z+2 and Z+4 with a polymorphic information content index (PIC) of 0.53) and six genotypes were evident in 119 Taiwanese. When compared with control subjects, the NIDDM group had a much less frequency of the Z+2 allele (14.0% vs. 23.9%). In addition, the Z+2 allele was noted to have a marginal protective effect for NIDDM in Taiwanese with the odds ratio of 0.52 (95% confidence interval (C.I.) 0.26-1.03, P = 0.058). For GCK2, four alleles (0, 2, 4 and 6 with a PIC of 0.48) and seven genotypes were identified. There was no significant difference in allele frequency between NIDDM and control groups in the locus of GCK2. Our data were in agreement with reports from American Blacks, Mauritian Creoles, Asian Indians, Japanese and Finnish--that there is a positive association of GCK1 and a negative association of GCK2 with NIDDM. Furthermore, the Z+2 allele was a protective factor for NIDDM in Taiwanese.

Alleles↗
PubMed1995

Incidence and progression of diabetic retinopathy among non-insulin-dependent diabetic subjects: a 4-year follow-up.

BACKGROUND: To assess the incidence and progression of diabetic retinopathy and explore risk factors associated with them among non-insulin-dependent diabetes mellitus (NIDDM) patients. METHODS: A total of 471 NIDDM subjects aged > or 40 were recruited from four primary health care centres of northern Taiwan in 1986 and followed up for 4 years. Their ocular fundi were clearly visible by ophthalmoscopy and the status of diabetic retinopathy could be graded. A structured questionnaire interview was conducted to collect basic data. Overnight fasting venous blood was collected every year to measure the levels of glucose, glycosylated haemoglobin (HbA1c), cholesterol and high density lipoprotein cholesterol. RESULTS: Among the 344 subjects who had no retinopathy initially, 66 subjects developed retinopathy 4 years later giving a 4-year cumulative incidence of 19.2%. Of the 120 subjects initially with background or preproliferative retinopathy, evidence of deterioration developed in 36 subjects. The cumulative incidence of progression was 30%. Seven subjects developed proliferative retinopathy giving a cumulative incidence of progression to proliferative retinopathy of 5.8%. The univariate analysis disclosed that the development of retinopathy was correlated with mean fasting blood glucose (MFBG) and HbA1c, diabetic duration, diabetic treatment and residential area. The progression of retinopathy correlated with MFBG and proteinuria, and the progression to proliferative retinopathy correlated with MFBG. Stepwise logistic regression analysis revealed that MFBG and HbA1c were the significant risk factors related to the development of retinopathy. CONCLUSIONS: Diabetic control assessed by MFBG or HbA1c was the significant risk factor correlated with the incidence and progression of retinopathy.

Adult↗
PubMed1995

Mitochondrial gene mutations in familial non-insulin-dependent diabetes mellitus in Taiwan.

Mitochondrial gene mutations are found to cause certain forms of diabetes mellitus and related syndromes. To study the prevalence of mitochondrial gene mutations in subjects with non-insulin-dependent diabetes mellitus (NIDDM) in Taiwan, 23 pedigrees with multiple siblings affected with NIDDM were consecutively collected from patients living in northern Taiwan. The A-to-G mutation at position 3243 np in the tRNA Leu gene and the mutation at position 8344 were screened by PCR-RFLP methods and confirmed by direct DNA sequence analysis. Among 23 NIDDM pedigrees, one pedigree was found to carry the 3243 np mutation. There was no 8344 np mutation in this series. Clinical features of this pedigree were consistent with mitochondrial disease in terms of maternal transmission, relatively early onset, non-obesity, insulin-requirement and association with hearing impairment. There was no correlation between the degree of heteroplasmy of mitochondrial gene mutation in leukocyte DNA and clinical severity. We conclude that a mitochondrial gene defect is an important genetic factor in familial cases with NIDDM in Taiwan.

Adult↗
PubMed1995

Transcomplementation of HLA DQA1-DQB1 in DR3/DR4 and DR3/DR9 heterozygotes and IDDM in Taiwanese families.

OBJECTIVE: To study the human leukocyte antigen (HLA)-DQ heterodimers in the susceptible DR haplotypes for patients with insulin-dependent diabetes mellitus (IDDM) in Taiwan. RESEARCH DESIGN AND METHODS: Extended class II HLA haplotypes were studied in 57 unrelated IDDM patients, 31 simplex IDDM families, and 105 unrelated control subjects recruited from the same area in Taiwan. Class II HLA genotyping was based on PCR-SSO DNA typing techniques. Extended class II HLA haplotypes were deduced unequivocally by the Taiwanese pedigree studies. RESULTS: DR3/DR3, DR3/DR4, and DR3/DR9 genotypes were strongly associated with IDDM susceptibility in this population. In addition to the reported DR3/DR4 in Caucasians, the heterozygotic effect of DR3/DR9 for IDDM was remarkable in the Taiwanese population. Extended HLA haplotypes studies revealed that DRB1*0301/DQA1*0501/DQB1*0201, DRB1*0405/DQA1*0301/DQB1*0302, and DRB1*0405/DQA1*0301/DQB1*0401 were the susceptible haplotypes in this population. There were several hypothetical ways to produce susceptible HLA-DQ heterodimers to explain the susceptibility carried by DR3/DR4 and DR3/DR9 genotypes. Among all DR4 subtypes, only DRB1*0405 was associated with the increased risk of IDDM. CONCLUSIONS: These data strongly suggest that the HLA-DR-associated IDDM susceptibility is most likely explained by the formation of the susceptible DQ heterodimers encoded by the DQA1/DQB1 either in cis or in trans.

Confidence Intervals↗
PubMed1995

Serum lipids and lipoprotein(a) concentrations in Chinese NIDDM patients. Relation to metabolic control.

OBJECTIVE: To compare serum blood lipids and lipoprotein(a) [Lp(a)] levels in Chinese non-insulin-dependent diabetes mellitus (NIDDM) patients and nondiabetic control subjects and also to determine the influence of diabetes control on serum Lp(a) concentration in Chinese individuals. RESEARCH DESIGN AND METHODS: We compared the serum blood lipids and Lp(a) levels in NIDDM patients (n = 100) and age- and sex-matched nondiabetic subjects (n = 100) who participated in a case-control study. Comparisons of Lp(a) concentrations were made between a normal control group, a group of diabetic patients with HbA1c < 8.0%, and a group of diabetic patients with HbA1c of 8% or higher. RESULTS: The diabetic patients had higher total triglyceride, apolipoprotein B (apo B), and apo B-to-apo AI ratios, but lower high-density lipoprotein (HDL) cholesterol and apo AI concentrations than nondiabetic controls (P < 0.001, P < 0.01, P < 0.001, P < 0.05, and P < 0.001, respectively). A similar pattern of distribution of Lp(a) levels according to the degree of metabolic control was seen in patients with NIDDM and nondiabetic controls. No correlation was observed between Lp(a) levels and total cholesterol, low-density lipoprotein cholesterol, HDL cholesterol, apo AI, apo B, and triglyceride levels in all diabetic patients. No difference in the Lp(a) levels was noted between diabetic patients and nondiabetic subjects, even in poorly controlled diabetic patients. CONCLUSIONS: In conclusion, Lp(a) levels are not elevated in diabetic patients, even in poorly controlled metabolic conditions.

Albuminuria↗
PubMed1995

Body composition and its relationship with physical activity and anthropometric factors in Chinese adults.

To evaluate the relationship of body composition with physical activity and other anthropometric factors, a group of 437 healthy Chinese men and women were recruited. Body composition was measured using the bioelectric impedance technique. Levels of physical activity (LPA) were classified as light, moderate and heavy. Anthropometric factors evaluated included body mass index (BMI), ponderal index (PI), waist-to-hip ratio (WHR), triceps skinfold thickness (TSF), mid-arm circumference, mid-forearm circumference, arm muscle circumference (AMC) and arm muscle area (AMA). Sex was found to be highly associated with body composition, with females having a higher percentage of body fat and males having a higher percentage of body lean mass. This gender difference was independent of age, physical activity or other anthropometric factors. An increased level of physical activity was associated with higher body lean mass and lower body fat. Sex, LPA, TSF, PI and WHR were all entered into the regression equations to estimate body composition. Sex and physical activity have an independent effect on body composition and the commonly used estimators for adiposity and fat distribution such as BMI, PI, TSF and WHR are closely correlated with body composition.

Adult↗
PubMed1995

HLA DQA1 genotypes and its interaction with HLA DQB1 in Chinese IDDM living in Taiwan.

To study the role of the HLA DQA1 gene and its interaction with DQB1 in the susceptibility of IDDM, subjects with insulin-dependent (type 1) diabetes mellitus and non-diabetic unrelated controls were recruited from a Chinese population living in northern Taiwan. HLA DQA1 exon 2 was enzymatically amplified by polymerase chain reaction. HLA DQA1 alleles were diagnosed by dot blotting and hybridization with 11 sequence-specific oligonucleotide probes. Among all the DQA1 alleles, DQA1*0301 and DQA1*0501 were more frequent while DQA1*0102, DQA1*0103 and DQA1*0601 were less frequent in Chinese with IDDM than in controls. Among the DQA1 genotypes, only DQA1*0301/0301 and DQA1*0301/0501 were associated with increased risk to IDDM while DQA1*0301/0601 and DQA1*0102/0103 were protective against IDDM in our population. As the cell surface HLA DQ molecules were formed from each DQA1 and DQB1 alleles either in cis- or trans-position, the numbers of susceptible HLA DQ alpha beta heterodimers were then derived from the genotypes of HLA DQA1/DQB1 in each person. The numbers of the possible diabetogenic DQ alpha beta dimers correlated with the degree of risk to IDDM (r = 0.92) but were not statistically significant (p > 0.05). Subjects with absence of diabetogenic HLA DQ molecules were resistant to developing IDDM while subjects with two or more forms of diabetogenic DQ molecules were associated with increased risk to IDDM. In conclusion, both DQA1 and DQB1 genes, which determine the formation of susceptible DQ alpha beta heterodimers, were significantly associated with IDDM in Chinese subjects living in Taiwan.

Alleles↗
PubMed1995

Increased prevalence of hypertension and long-term arsenic exposure.

To examine the association between long-term exposure to inorganic arsenic and the prevalence of hypertension, we studied a total of 382 men and 516 women residing in villages where arseniasis was hyperendemic. Hypertension was defined as a systolic blood pressure of 160 mm Hg or greater, a diastolic blood pressure of 95 mm Hg or greater, or a history of hypertension treated regularly with antihypertensive drugs. The long-term arsenic exposure was calculated from the history of artesian well water consumption obtained through standardized interviews based on a structured questionnaire and the measured arsenic concentration in well water. Residents in villages where long-term arseniasis was hyperendemic had a 1.5-fold increase in age- and sex-adjusted prevalence of hypertension compared with residents in nonendemic areas. Duration of artesian well water consumption, average arsenic concentration in drinking water, and cumulative arsenic exposure were all significantly associated with hypertension prevalence. The higher the cumulative arsenic exposure, the higher the prevalence of hypertension. This dose-response relation remained significant after adjustment for age, sex, diabetes mellitus, proteinuria, body mass index, and serum triglyceride level. The results suggest that long-term arsenic exposure may induce hypertension in humans.

Adult↗
PubMed1994

Ingested inorganic arsenic and prevalence of diabetes mellitus.

To examine the association between ingested inorganic arsenic and prevalence of diabetes mellitus, in 1988, the authors studied 891 adults residing in villages in southern Taiwan where arseniasis is hyperendemic. The status of diabetes mellitus was determined by an oral glucose tolerance test and a history of diabetes regularly treated with sulfonylurea or insulin. The cumulative arsenic exposure in parts per million-years was calculated from the detailed history of residential addresses and duration of drinking artesian well water obtained through standardized interviews based on a structured questionnaire and the arsenic concentration in well water. The body mass index was derived from body height and weight measured according to a standard protocol, while the physical activity at work was also obtained by questionnaire interviews. Residents in villages where the chronic arseniasis was hyperendemic had a twofold increase in age- and sex-adjusted prevalence of diabetes mellitus compared with residents in Taipei City and the Taiwan area. There was a dose-response relation between cumulative arsenic exposure and prevalence of diabetes mellitus. The relation remained significant after adjustment for age, sex, body mass index, and activity level at work by a multiple logistic regression analysis giving a multivariate-adjusted odds ratio of 6.61 and 10.05, respectively, for those who had a cumulative arsenic exposure of 0.1-15.0 and greater than 15.0 ppm-year compared with those who were unexposed. These results suggest the chronic arsenic exposure may induce diabetes mellitus in humans.

Adult↗
PubMed1994

HLA-DQB1 codon 57 and IDDM in Chinese living in Taiwan.

OBJECTIVE: To study the human leukocyte antigen (HLA)-DQB1 genetic background in the Chinese population in Taiwan and its association with the low incidence of insulin-dependent diabetes mellitus (IDDM) in this population. RESEARCH DESIGN AND METHODS: Forty-eight IDDM patients and 59 nondiabetic unrelated control subjects were recruited from the population in Taiwan. HLA-DQB1 exon 2 was enzymatically amplified by polymerase chain reaction. HLA-DQB1 alleles were diagnosed by dot blotting and hybridization with 16 sequence-specific oligonucleotide probes. RESULTS: DQB1*0201 and DQB1*0302 alleles were more frequent and DQB1*0301 and DQB1*0601 were less frequent in Chinese with IDDM than in control subjects. Genotypes for homozygous non-aspartic acid residue (NA/NA) at position 57 were positively associated with IDDM at a relative risk of 4.34 (P < 0.001), and those for homozygous aspartic acid (A/A) were negatively associated with IDDM at a relative risk of 0.14 (P < 0.001). Among the NA/A heterozygotes, only DQB1*0201/DQB1*0303 was significantly increased in IDDM subjects. CONCLUSIONS: The amino acid residue at position 57 of HLA-DQ beta-chain is significantly associated with the development or prevention of IDDM in Chinese subjects living in Taiwan. Other genetic and environmental factors may also play important roles in pathogenesis of IDDM.

Adolescent↗
PubMed1994

Mortality in diabetic patients after lower extremity amputations.

This study evaluates the prognostic factors and causes associated with mortality in Chinese diabetic patients after lower extremity amputations. Medical records of all diabetic patients admitted to the National Taiwan University Hospital for leg amputations from 1982 to 1991 were reviewed. Demographic data, medical history, amputation levels and admission routines, including fasting plasma glucose, cholesterol, triglycerides, blood urea nitrogen, creatinine, urine protein and electrocardiograms, and bacterial culture done during the admission period were recorded. The vital status of the patients was followed by personal contact and mortality was ascertained from government computer records. The causes of death were recorded according to the death certificates. Univariate analysis and multivariate Cox's proportional hazards model were used to identify the prognostic factors associated with mortality. A total of 87 diabetic amputees, of whom 34 died, were found within this 10-year period. Cerebral infarction, infection and diabetes mellitus were the most commonly reported causes of death. Their calculated mortality was 5.95 times higher than the mortality rate of the age-comparable population in Taiwan. A history of hypertension and coronary heart disease were found to be the best indicators for predicting a fatal outcome with rate ratios of over two-fold. This study shows that post-amputational mortality is high in diabetic patients and that the major cause of death is cerebral infarction. The major cause of death in this study differs from that reported for Caucasians, for whom cardiovascular disease is the most important cause of death.

Adult↗