Wen-Harn Pan

Association between Body-Mass Index and Risk of Death in More Than 1 Million Asians

BACKGROUND Most studies that have evaluated the association between the body-mass index (BMI) and the risks of death from any cause and from specific causes have been conducted in populations of European origin. METHODS We performed pooled analyses to evaluate the association between BMI and the risk of death among more than 1.1 million persons recruited in 19 cohorts in Asia. The analyses included approximately 120,700 deaths that occurred during a mean follow-up period of 9.2 years. Cox regression models were used to adjust for confounding factors. RESULTS In the cohorts of East Asians, including Chinese, Japanese, and Koreans, the lowest risk of death was seen among persons with a BMI (the weight in kilograms divided by the square of the height in meters) in the range of 22.6 to 27.5. The risk was elevated among persons with BMI levels either higher or lower than that range--by a factor of up to 1.5 among those with a BMI of more than 35.0 and by a factor of 2.8 among those with a BMI of 15.0 or less. A similar U-shaped association was seen between BMI and the risks of death from cancer, from cardiovascular diseases, and from other causes. In the cohorts comprising Indians and Bangladeshis, the risks of death from any cause and from causes other than cancer or cardiovascular disease were increased among persons with a BMI of 20.0 or less, as compared with those with a BMI of 22.6 to 25.0, whereas there was no excess risk of either death from any cause or cause-specific death associated with a high BMI. CONCLUSIONS Underweight was associated with a substantially increased risk of death in all Asian populations. The excess risk of death associated with a high BMI, however, was seen among East Asians but not among Indians and Bangladeshis.

Serum uric acid level as an independent risk factor for all‐cause, cardiovascular, and ischemic stroke mortality: A chinese cohort study

OBJECTIVE The association between hyperuricemia and cardiovascular events has been documented in high-risk groups, but is still undetermined in general populations, especially Chinese. This study assessed the temporal association between serum uric acid level, hyperuricemia, and cardiovascular mortality. METHODS A prospective cohort study of 41,879 men and 48,514 women ages > or = 35 years was conducted using data from the MJ Health Screening Centers in Taiwan. Mortality from all causes, total cardiovascular disease (CVD), ischemic stroke, congestive heart failure, hypertensive disease, and coronary heart disease were compared according to increasing serum uric acid levels. RESULTS A total of 1,151 (21.2%) events of 5,427 total deaths were ascribed to CVD (mean followup 8.2 years). Hazard ratios (HRs) for hyperuricemia (serum uric acid level >7 mg/dl) were estimated with Cox regression model after adjusting for age, sex, body mass index, cholesterol, triglycerides, diabetes, hypertension, heavy cigarette smoking, and frequent alcohol consumption. In all patients, HRs were 1.16 (P < 0.001) for all-cause mortality, 1.39 (P < 0.001) for total CVD, and 1.35 (P = 0.02) for ischemic stroke. In subgroup analysis, the HRs for cardiovascular risk remained significant in patients with hypertension (1.44, P < 0.001) and in patients with diabetes (1.64, P < 0.001). In addition, in a low metabolic risk subgroup, the HRs for all-cause mortality and total cardiovascular morbidity were 1.24 (P = 0.02) and 1.48 (P = 0.16), respectively. CONCLUSION Hyperuricemia was an independent risk factor of mortality from all causes, total CVD, and ischemic stroke in the Taiwanese general population, in high-risk groups, and potentially in low-risk groups.

Influence of Metabolic Syndrome and General Obesity on the Risk of Ischemic Stroke

Background and Purpose— In 2005, the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) guideline lowered the fasting glucose cut point used to define metabolic syndrome (MS). This study investigated the influence of MS on ischemic stroke (IS) risk using both the original and revised definitions. In addition, because abdominal obesity is the measure of obesity used in the guideline to define MS, we also investigated whether general obesity (GOB) should be considered in the definition of MS. Methods— Baseline data from 3453 adults (≥20 years of age) in the Cardiovascular Diseases Risk Factor Two-Township Study were linked to insurance claim and death certificate records. The 2001 and 2005 NCEP-ATP III definitions were used with Asian and Taiwanese specific cut-off values for waist circumference and body mass index. Hazard ratios of MS and GOB on IS were calculated using Cox models, and the Kaplan–Meier method was used to derive free-of-IS survival curves. Results— During 10.4 years of follow-up, 132 persons developed IS. Hazard ratios of subjects with 1 to 2 and ≥3 MS component disorders were 2.69 and 4.30, respectively, under the 2001 definition, and 3.16 and 5.15, respectively, under the 2005 definition (all P values <0.05). MS subjects with GOB had reduced survival at a borderline significance level. Adding GOB in the MS definition did not significantly alter the number of subjects with MS nor the ability to predict stroke risk. Replacing abdominal obesity with GOB in MS definition reduced the number slightly and increased the hazard ratio. Conclusion— MS predicted IS and the 2005 NCEP definition showed a stronger dose-response relationship with IS. Adding GOB to the existing MS definition had limited benefit.

Association between body mass index and cardiovascular disease mortality in east Asians and south Asians: pooled analysis of prospective data from the Asia Cohort Consortium

Objective To evaluate the association between body mass index and mortality from overall cardiovascular disease and specific subtypes of cardiovascular disease in east and south Asians. Design Pooled analyses of 20 prospective cohorts in Asia, including data from 835 082 east Asians and 289 815 south Asians. Cohorts were identified through a systematic search of the literature in early 2008, followed by a survey that was sent to each cohort to assess data availability. Setting General populations in east Asia (China, Taiwan, Singapore, Japan, and Korea) and south Asia (India and Bangladesh). Participants 1 124 897 men and women (mean age 53.4 years at baseline). Main outcome measures Risk of death from overall cardiovascular disease, coronary heart disease, stroke, and (in east Asians only) stroke subtypes. Results 49 184 cardiovascular deaths (40 791 in east Asians and 8393 in south Asians) were identified during a mean follow-up of 9.7 years. East Asians with a body mass index of 25 or above had a raised risk of death from overall cardiovascular disease, compared with the reference range of body mass index (values 22.5-24.9; hazard ratio 1.09 (95% confidence interval 1.03 to 1.15), 1.27 (1.20 to 1.35), 1.59 (1.43 to 1.76), 1.74 (1.47 to 2.06), and 1.97 (1.44 to 2.71) for body mass index ranges 25.0-27.4, 27.5-29.9, 30.0-32.4, 32.5-34.9, and 35.0-50.0, respectively). This association was similar for risk of death from coronary heart disease and ischaemic stroke; for haemorrhagic stroke, the risk of death was higher at body mass index values of 27.5 and above. Elevated risk of death from cardiovascular disease was also observed at lower categories of body mass index (hazard ratio 1.19 (95% confidence interval 1.02 to 1.39) and 2.16 (1.37 to 3.40) for body mass index ranges 15.0-17.4 and <15.0, respectively), compared with the reference range. In south Asians, the association between body mass index and mortality from cardiovascular disease was less pronounced than that in east Asians. South Asians had an increased risk of death observed for coronary heart disease only in individuals with a body mass index greater than 35 (hazard ratio 1.90, 95% confidence interval 1.15 to 3.12). Conclusions Body mass index shows a U shaped association with death from overall cardiovascular disease among east Asians: increased risk of death from cardiovascular disease is observed at lower and higher ranges of body mass index. A high body mass index is a risk factor for mortality from overall cardiovascular disease and for specific diseases, including coronary heart disease, ischaemic stroke, and haemorrhagic stroke in east Asians. Higher body mass index is a weak risk factor for mortality from cardiovascular disease in south Asians.

Body Mass Index and Diabetes in Asia: A Cross-Sectional Pooled Analysis of 900,000 Individuals in the Asia Cohort Consortium

Background The occurrence of diabetes has greatly increased in low- and middle-income countries, particularly in Asia, as has the prevalence of overweight and obesity; in European-derived populations, overweight and obesity are established causes of diabetes. The shape of the association of overweight and obesity with diabetes risk and its overall impact have not been adequately studied in Asia. Methods and Findings A pooled cross-sectional analysis was conducted to evaluate the association between baseline body mass index (BMI, measured as weight in kg divided by the square of height in m) and self-reported diabetes status in over 900,000 individuals recruited in 18 cohorts from Bangladesh, China, India, Japan, Korea, Singapore and Taiwan. Logistic regression models were fitted to calculate cohort-specific odds ratios (OR) of diabetes for categories of increasing BMI, after adjustment for potential confounding factors. OR were pooled across cohorts using a random-effects meta-analysis. The sex- and age-adjusted prevalence of diabetes was 4.3% in the overall population, ranging from 0.5% to 8.2% across participating cohorts. Using the category 22.5–24.9 Kg/m2 as reference, the OR for diabetes spanned from 0.58 (95% confidence interval [CI] 0.31, 0.76) for BMI lower than 15.0 kg/m2 to 2.23 (95% CI 1.86, 2.67) for BMI higher than 34.9 kg/m2. The positive association between BMI and diabetes prevalence was present in all cohorts and in all subgroups of the study population, although the association was stronger in individuals below age 50 at baseline (p-value of interaction<0.001), in cohorts from India and Bangladesh (p<0.001), in individuals with low education (p-value 0.02), and in smokers (p-value 0.03); no differences were observed by gender, urban residence, or alcohol drinking. Conclusions This study estimated the shape and the strength of the association between BMI and prevalence of diabetes in Asian populations and identified patterns of the association by age, country, and other risk factors for diabetes.

Dietary exposure to nitrite and nitrosamines and risk of nasopharyngeal carcinoma in Taiwan.

Previous studies of nasopharyngeal carcinoma (NPC) have found elevated risks with higher consumption of salted fish and preserved foods, particularly during childhood. These foods can contain high levels of nitrosamines; however, most studies have not estimated exposure to nitrosamines directly. We conducted a case‐control study in Taiwan to evaluate dietary intakes and NPC risk. A total of 375 cases (99% response rate) and 327 controls (88% response rate) were interviewed about their diet as an adult and at age 10 using a food‐frequency questionnaire. We interviewed mothers of participants about their childs diet at age 10, age 3 and during weaning and the mothers diet while she was breast‐feeding. Mothers of 96 cases and 120 controls were interviewed. Nitrosamine and nitrite levels were assigned to 66 foods based on published values. Intake of nitrosamines and nitrite as an adult was not associated with risk of NPC. High intakes of nitrosamines and nitrite during childhood and weaning were associated with increased risks of NPC for foods other than soy products. Adjusted odds ratios for the highest quartile were 2.2 [95% confidence interval (CI) 0.8–5.6] for age 10, 2.6 (95% CI 1.0–7.0) for age 3 and 3.9 (95% CI 1.4–10.4) for weaning diet. Intakes of nitrite and nitrosamines from soybean products during childhood and weaning were inversely associated with risk. Soybeans contain known inhibitors of nitrosation, and thus may explain the inverse association we observed. Our results suggest that nitrosamine and nitrite intake during childhood may play a role in the development of NPC. Int. J. Cancer 86:603–609, 2000. Published 2000 Wiley‐Liss, Inc.

Prevalence of overweight and obesity and its associated factors: findings from National Nutrition and Health Survey in Taiwan, 1993-1996

BACKGROUND To report the overall and regional prevalence of obesity/overweight in Taiwan and to study its associated risk factors. METHODS A total of 3046 adults > or = 20 years of age collected in National Nutrition and Health Survey in Taiwan, 1993-1996. RESULTS Prevalence rates of overweight and obesity were 21.1 and 4.0% under the current WHO definition. The prevalence rates of overweight and obesity, using the Taiwanese definition (BMI = 24-26.99 kg/m(2) and > or = 27 kg/m(2), respectively), were 22.9 and 10.5% for males and 20.3 and 13.2% for females, respectively. The highest prevalence rates of obesity were found in the mountainous areas. In addition to age and residing location, education level in women and metabolic equivalent (MET) score and alcohol consumption in men were correlates of obesity. Effects of nutrition/health-related behaviors might be in part explained by education level and residing location of the subjects. CONCLUSION The prevalence of obesity defined by WHO criteria among people in Taiwan was moderate, with considerable regional variation. The regional differences in obesity prevalence could not be completely accounted for by the sociodemographic and lifestyle factors studied.

Han Chinese Cell and Genome Bank in Taiwan: Purpose, Design and Ethical Considerations

a Institute of Biomedical Sciences, Academia Sinica, b Department of Political Sciences, National Taiwan University, c Research Center for Humanities and Social Sciencies, Academia Sinica, d Center for Survey Research, Research Center for Humanities and Social Sciencies, Academia Sinica, and e Department of Philosophy, National Chengchi University, Taipei , Taiwan, ROC goal is to develop Taiwan’s competitive edge in medical research particularly for prognosis, diagnosis, and treatment of Taiwanese important genetic diseases. The Han Chinese cell and Genome Bank project was jointly supported by NRPGM and Academia Sinica. Comprehensive cores have been established in NRPGM to complement relevant studies. The National Clinical Core and National High-throughput Genotyping Core, funded by NSC and directed by the Institute of Biomedical Sciences, Academia Sinica, Taiwan, played major roles in carrying out fi eld work and in the genotyping of the genetic material. A policy and mechanisms for the release of DNA information have been established for genetic research communities in Taiwan and abroad. In order to obtain a representative sample of genetic material for the bank; a stratifi ed, 3-staged, probability clustering sampling scheme (see appendix, table 1 , and fi g. 1 ) was adopted. Sampling was designed to have around 278 male and 278 female subjects respectively in each of the 6 age groups (20–, 30–, 40–, 50–, 60–, 70–) so that there would be suffi cient numbers of sex/age matched controls for a range of diseases. Of the people living in the registered households that were contacted, a total of 73.4% took part in the study. Plasma, DNA, and lymphocytes were collected and banked, and measurements including basic blood chemistry, blood pressure, peak fl ow, and anthropometric parameters were taken (see table 2 ). A questionnaire ( table 2 ) on ethnicity, disease history and medication, life styles, and cognitive function of the elderly was administered by trained nurses in a door-to-door survey, following a standardized protocol. Complete questionnaire and bio-specimen data were available for 3,380 people. This information can be used to defi ne phenotypes for association study and to select controls. The EBV-transformed lymphoblastoid cell lines had been established by the Bioresource Collection and Research Center, Hsinchu, Taiwan. From October 1, 2002 to January 14, 2004, the Institute of Biomedical Sciences, Academia Sinica, Taiwan, conducted fi eld work involving interviewing and recruiting 3,380 Han Chinese in order to establish a Han Chinese Cell and Genome Bank in Taiwan. The aims of this undertaking were several fold: (1) to collect representative genetic material for population genetic research, particularly for use as controls in disease association studies in Chinese people, (2) to document the genetic diversity of Han Chinese in Taiwan at the beginning of the 21st century, and (3) to create a bank of material that will prevent the repetitive collection of genetic material from the general public by the academic and medical community. The National Science Council (NSC) in Taiwan has launched the ‘National Research Program for Genomic Medicine (NRPGM)’ in 2002 as the fi rst phase of Taiwan’s Biotechnology Initiative in response to the deciphering of the human genome in 2000. The

Dietary factors associated with physician-diagnosed asthma and allergic rhinitis in teenagers: analyses of the first Nutrition and Health Survey in Taiwan.

The occurrence of asthma and allergy are related to lifestyle factors, and dietary pattern may be one of the contributing factors.

Dietary fats and asthma in teenagers: analyses of the first Nutrition and Health Survey in Taiwan (NAHSIT)

Background The occurrence of asthma may be associated with dietary factors.