Choon-Khim Chong

Lipid Profile and Peripheral Vascular Disease in Arseniasis-Hyperendemic Villages in Taiwan:

To examine whether lipid abnormalities contributed to the endemic peripheral vascular disease (PVD) in villages where arseniasis was hyperendemic in Taiwan, the authors studied 533 adults with Doppler ultrasound and lipid profiles including total cholesterol, triglyceride, high- and low-density lipoprotein cholesterol, apolipoprotein AI, and apolipoprotein B. Among them, 63 had PVD based on an ankle-brachial index < 0.90. Long-term arsenic exposure indices including cumulative arsenic exposure in mg/L-years, duration of drinking artesian well water in years, and duration of living in arseniasis- hyperendemic villages in years were calculated from detailed history obtained through standardized interviews based on a structured questionnaire and arsenic concentration in well water. Possible confounders including age, sex, body mass index, cigarette smoking, and disease status of diabetes mellitus and hypertension were considered in the analyses. None of the lipid profiles differed significantly between the presence and absence of PVD. The odds ratios for PVD did not differ among different quintiles of lipid profiles with the lowest quintile as the referent. However, a significant dose-response relation was found for the long-term arsenic exposure indices. The multivariate-adjusted odds ratios for cumulative arsenic exposure of 0.1∼19.9 and ≥ 20 mg/L-years were 2.77 and 4.68, respectively, compared with the unexposed. These results suggest that the PVD in arse niasis-hyperendemic villages is correlated with ingested inorganic arsenic and not with the lipid profiles.

Abnormal Peripheral Microcirculation in Seemingly Normal Subjects Living in Blackfoot-Disease-Hyperendemic Villages in Taiwan

Blackfoot disease (BFD) is an endemic peripheral arterial disease confined to the southwestern coast of Taiwan. The cause of the disease has been ascribed to the high-arsenic artesian well water. The purpose of this study was to examine the possible association between the long-term exposure to artesian well water and the change in microvascular circulation in the absence of peripheral arterial insufficiency. A total of 45 men living in the BFD-hyperendemic villages and another 51 age- sex- body-mass index-matched men who lived in nonendemic villages nearby were recruited into this study. All subjects were free from peripheral vascular disease (resting ankle-brachial index > 1.00), clinical claudication, cigarette smoking, diabetes mellitus, hypertension, ischemic heart disease, cerebral infarction and obesity. Laser Doppler flowmetry was used to measure the peripheral microcirculation on the big toes both at 36 degrees C (basal perfusion, Pb) and after a hyperthermic test at 42 degrees C (Ph). The time required to reach Ph (T), and the average rate (R) of increase from Pb to Ph measured by (Ph-Pb)/T were also calculated. Results showed that those living in the BFD-hyperendemic area had a lower Pb [32.8 +/- 6.0 perfusion units (PU) vs. 67.0 +/- 4.3 PU, p < 0.001], a lower Ph (193.2 +/- 13.6 vs. 231.1 +/- 6.3 PU, p < 0.005), a longer T (3.04 +/- 0.19 vs. 1.31 +/- 0.08 min, p < 0.001) and a slower rate of increase from Pb to Ph (48.0 +/- 4.8 vs. 76.2 +/- 5.4 PU/min, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Age-related risk of mortality from bladder cancer in diabetic patients: a 12-year follow-up of a national cohort in Taiwan.

Background. To compare bladder cancer mortality between diabetic patients and the general population. Materials and methods. Yearly sex-specific mortality rates for age 25–64, 65–74, and ≥75 years in Taiwanese general population for 1995–2006 were calculated; 113,347 diabetic men and 131,573 diabetic women aged ≥25 years recruited in 1995–1998 were followed prospectively. Results. In the general population, 4,943 men and 2,291 women died of bladder cancer, and aging was associated with increased risk. Although the trend of crude mortality was increasing in either sex, the trend of age-standardized rates had been steady. The average crude and age-standardized mortality rates were 5.35 and 5.98 (per 100,000 population), respectively, for men; and were 2.63 and 3.02 for women. A total of 224 diabetic men and 126 diabetic women died of bladder cancer with crude mortality of 26.0 and 11.9 per 100,000 person-years, respectively. The relative risk of bladder cancer mortality (95% confidence interval) for diabetic patients was 2.18 (1.75–2.72), 2.50 (2.06–3.04), and 5.95 (4.57–7.74), in men, and 1.34 (0.96–1.89), 2.48 (1.92–3.19), and 7.44 (5.46–10.15), in women, for ages ≥75, 65–74, and 25–64 years, respectively. Conclusions. Diabetic patients had a higher risk of bladder cancer mortality, which is more remarkable in the younger population.

The incidence of type 2 diabetes mellitus in Taiwan

Currently, diabetes mellitus is the fifth leading cause of death in Taiwan. The trends of diabetes mortality is increasing steadily. Epidemiologic studies also showed increasing prevalence of diabetes mellitus over the past few decades. The incidence of diabetes mellitus in Taiwan has only been studied in recent 10 years. The areas that have been included as study areas for diabetes incidence are Kin-Chen (Kinmen), Chu-Dung, Pu-Tzu, Pu-Li and Pu-Tai. The reported incidence rates ranged from 1.0 to 4.0% per year for people with varying degrees of baseline plasma glucose levels not reaching the diagnosis of diabetes mellitus according to the criteria of the World Health Organization. Age, baseline glucose level, and obesity are important predictors for the development of diabetes mellitus. In the Pu-Tai study, which was aimed at following a group of people who had been living in the hyperendemic villages of blackfoot disease and had been exposed to arsenic from drinking artesian well water, the incidence of diabetes mellitus was calculated to be 27.4 per 1000 person years. The incidence of diabetes mellitus in these arseniasis-hyperendemic villages correlated with age, body mass index and cumulative arsenic exposure.

Real-time PCR for rapid genotyping of angiotensin-converting enzyme insertion/deletion polymorphism

OBJECTIVE To develop a real-time PCR technique for detection of the insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) gene. DESIGN AND METHODS Three primers were designed for performing real-time PCR in the presence of SYBR Green I as flurochrome followed by melting curve analysis. Forty human genomic DNA that have been genotyped by two-rounds of conventional PCR were used for evaluation of this technique. RESULTS Melting curve analysis indicated the melting peak at 73.9 degrees C and 76.2 degrees C corresponding to the presence of I and D alleles, respectively. Comparable genotyping results were obtained by both conventional and real-time PCR. Besides, the mistyping of ID allele individuals by the first run of conventional PCR were accurately genotyped by single-tube real time PCR. CONCLUSIONS The real-time PCR method presented in this study provides a rapid and sensitive way for genotyping of ACE gene that may be suitable for large-scale clinical and epidemiologic study.

Prevalence and risk factors for stroke in Type 2 diabetic patients in Taiwan: A cross-sectional survey of a national sample by telephone interview

Aims  To determine the prevalence and risk factors for stroke in patients with Type 2 diabetes mellitus (T2DM) and the age‐specific prevalence odds ratios (POR) in comparison with the general population in Taiwan.

Blackfoot disease in Taiwan: its link with inorganic arsenic exposure from drinking water.

aged 20–39 y were 0.5%, 1.3%, and 1.4%, respectively; for residents aged 40–59 y, 1.1%, 3.2%, and 4.7%, respectively; and for residents aged over 60 y, 2.0% ,3 .2% ,a nd 6.1%, respectively (1). This study suggested that the prevalence of BFD increased in proportion to increasing arsenic concentrations of the well water.

Angiotensin-converting enzyme gene polymorphism and stroke in type 2 diabetic patients in Taiwan

Background  The effect of traditional risk factors on the association between angiotensin‐converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and stroke was rarely studied previously. We investigated such effect in Taiwanese type 2 diabetic patients.

Angiotensin-Converting Enzyme Genotype and Peripheral Arterial Disease in Diabetic Patients

We investigated the effect of traditional risk factors (hypertension, dyslipidemia and smoking) on the association between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and peripheral arterial disease (PAD) in 945 (454 men and 491 women) Taiwanese type 2 diabetic patients with a mean age of 63.5 (SD: 11.4) years. Among them, 81 (31 men and 50 women) had PAD (ankle-brachial index <0.9). The adjusted odds ratios (95% confidence intervals) were 2.48 (1.18–5.21), 1.69 (1.00–2.85) and 1.64 (1.12–2.39), respectively, for recessive (DD versus II + ID), dominant (DD + ID versus II) and additive (II = 0, ID = 1 and DD = 2) models. While analyzing the interaction between DD and the individual risk factor of hypertension, smoking and dyslipidemia, patients with the risk factor and with DD had the highest risk compared to referent patients without the risk factor and with II/ID. The respective adjusted odds ratios were 5.41 (2.05–14.31), 7.38 (1.87–29.06) and 4.64 (1.70–12.64). We did not find a significant interaction between DD and any of the risk factors under multiplicative or additive scale. In conclusion, traditional risk factors (hypertension, smoking and dyslipidemia) play an important role in the association between ACE genotypes and PAD. Patients with DD genotype and traditional risk factors are at the highest risk.

Joint effects of hypertension, smoking, dyslipidemia and obesity and angiotensin-converting enzyme DD genotype on albuminuria in Taiwanese patients with type 2 diabetes mellitus

OBJECTIVE We investigated the individual and joint effects of hypertension, smoking, dyslipidemia, and obesity and angiotensin-converting enzyme (ACE) DD genotype on albuminuria in Taiwanese type 2 diabetic patients. DESIGNS AND METHODS ACE genotypes were determined in 519 (287 men and 232 women) patients aged 58.5 (SD: 9.0) years. Among them, 240 had albuminuria (urinary albumin-to-creatinine ratio > or =30 microg/mg). Logistic regression was used to evaluate the individual and joint effects of risk factors and DD classified by two-by-four table. RESULTS The adjusted odds ratios were significant for hypertension, smoking and obesity but not for DD and dyslipidemia in models evaluating individual effects. However, while analyzing the joint effects of DD and hypertension, smoking, dyslipidemia and obesity, the respective adjusted odds ratios were 3.253 (1.261-8.391), 3.016 (1.086-8.376), 2.385 (1.010-5.630) and 2.508 (1.117-5.631). CONCLUSION Hypertension, smoking, dyslipidemia and obesity jointly play an important role with DD genotype in mediating albuminuria.