Ruey-Shiung Lin

Optimal cut-off values for obesity: Using simple anthropometric indices to predict cardiovascular risk factors in Taiwan

BACKGROUND: The increased health risks associated with obesity have been found to occur in Asians at lower body mass indices (BMIs). To determine the optimal cut-off values for overweight or obesity in Taiwan, we examined the relationships between four anthropometric indices and cardiovascular risk factors.METHODS: The data were collected from four health-screening centers from 1998 to 2000 in Taiwan. Included were 55u2005563 subjects (26u2005359 men and 29u2005204 women, mean age=37.3±10.9 and 37.0±11.1u2005y, respectively). None had known major systemic diseases or were taking medication. Individual body weight, height, waist circumference (WC), and a series of tests related to cardiovascular risk (blood pressure, fasting plasma glucose, triglycerides, total cholesterol, low- and high-density lipoprotein cholesterol) were assessed and their relationships were examined. Receiver operating characteristic (ROC) analysis was used to find out the optimal cut-off values of various anthropometric indices to predict hypertension, diabetes mellitus and dyslipidemia.RESULTS: Of the four anthropometric indices we studied, waist-to-height ratio (WHtR) in women was found to have the largest areas under the ROC curve (women=0.755, 95% CI 0.748–0.763) relative to at least one risk factor (ie hypertension or diabetes or dyslipidemia). The optimal cut-off values for overweight or obesity from our study in men and women showed that BMIs of 23.6 and 22.1u2005kg/m2, WCs of 80.5 and 71.5u2005cm, waist-to-hip ratios (WHpR) of 0.85 and 0.76, and WHtR of 0.48 and 0.45, respectively, may be more appropriate in Taiwan.CONCLUSIONS: WHtR may be a better indicator for screening overweight- or obesity-related CVD risk factors than the other three indexes (BMI, WC and WHpR) in Taiwan. Our study also supported the hypothesis that the cut-off values using BMI and WC to define obesity should be much lower in Taiwan than in Western countries.

Four anthropometric indices and cardiovascular risk factors in Taiwan.

OBJECTIVE: To examine the relationships between four anthropometric measurements and cardiovascular risk factors in Taiwan.DESIGN: The data was collected from four nationwide health screen centers in Taiwan from 1998 to 1999.SUBJECTS: A total of 38 556 subjects: 18 280 men and 20 276 women, mean age=37.0±11.1u2005y. None had any known major systemic diseases or were currently on medication.MEASUREMENTS: Individual body weight, height, waist circumference (WC), and cardiovascular risk factors (blood pressure, fasting plasma glucose, triglycerides, total cholesterol level, low-density and high-density-lipoprotein cholesterol level) were assessed and their relationships were examined.RESULTS: In both sexes, with increasing body mass index (BMI), WC, WHpR (waist-to-hip ratio) and WHtR (waist-to-height ratio), there were significantly higher risks of hypertension, impaired fasting glucose, diabetes and dyslipidemia (P<0.001) in almost all age groups. In the age groups older than 65, however, the relationships were statistically inconsistent.CONCLUSIONS: In Taiwan, the four anthropometric indexes (BMI, WC, WHpR, WHtR) are closely related to cardiovascular risk factors.

Body Mass Index May Modify Asthma Prevalence Among Low-Birth-Weight Children

Childhood asthma, a growing health concern, has been associated with low birth weight and elevated body mass index. This study tested the hypothesis that overweight and obese adolescents with a history of low birth weight are at even greater risk of developing asthma. A cohort of 75,871 junior high school students was screened for asthma during 1995-1996 in Taiwan. Birth weight and estimated gestational age were obtained from the birth registry. Logistic regression and simple regression analyses were adjusted for confounding variables. Asthma was more prevalent in those with birth weights below 3,000 g and higher adolescent body mass indexes. Furthermore, those with both characteristics were consistently most likely to have asthma. Whether the asthma diagnosis among low-birth-weight subjects was assigned by physicians or medical questionnaire, the risks were elevated for both overweight (physician diagnosis: odds ratio = 1.41; medical questionnaire: odds ratio = 1.25) and obese (physician diagnosis: odds ratio = 1.38; medical questionnaire: odds ratio = 1.47) boys as well as overweight (physician diagnosis: odds ratio = 1.63; medical questionnaire: odds ratio = 1.30) and obese (physician diagnosis: odds ratio = 1.44; medical questionnaire: odds ratio = 1.32) girls (P < 0.05). Low birth weight predisposes one to develop asthma, and excess body mass amplifies the risk. A sex difference was observed. This study suggests that prenatal care and nutritional counseling could reduce asthma prevalence.

Childhood diabetes identified in mass urine screening program in Taiwan, 1993–1999

OBJECTIVEnTo describe the gender differences in cases and characteristics of diabetes mellitus (DM) that can be identified from a mass urine screen program for school children in Taiwan.nnnMETHODnScreening for the childhood asymptomatic proteinuria and glucosuria began in 1992 for school children. Students were instructed to collect mid-stream samples of the first morning urine for glucosuria and proteinuria tests using urine strip devices. Students with positive results for glucose and/or protein and/or occult blood in the first examination received a second urine test. The third screening test was performed for urine and fasting blood sample for 11-item examinations if the second test was positive. The 1997 criteria of American Diabetes Association were used for defining DM.nnnRESULTSnApproximately 2,615,000-2,932,000 students received the preliminary screening each semester. The overall average rates of newly identified diabetes from 1993 to 1999 were 8.3 per 100,000 among boys, and 12.0 per 100,000 among girls. The average rate of new cases increased significantly from sixth grade for boys and fourth grade for girls, with peak rates of 14.7 per 100,000 in eighth grade for boys and 19.0 per 100,000 in sixth grade for girls. Similar prevalence trends by sex and grade were observed, higher in girls than in boys.nnnCONCLUSIONSnThis mass screening data suggest that childhood diabetes of all types in Taiwan is elevated in the age of puberty and higher in girls than in boys.

Esterase D and retinoblastoma gene loci are tightly linked to Wilson's disease in Chinese pedigrees from Taiwan

SummaryWilsons disease (WD) is a rare autosomal recessive disorder and has been mapped to the long arm of chromosome 13 (q14.1). We have analyzed the segregation of esterase D (ESD) and retinoblastoma (RB) gene loci in ten families of Chinese WD subjects living in Taiwan. The polymorphic information content (PIC) for ESD and RB was 0.18 and 0.31, respectively. We confirmed a tight linkage between these loci and WD with a lod score of 3.33 by multipoint linkage analysis. The data from this limited number of pedigrees also suggested the following order: centromere-WD-RB-ESD or centromere-ESD-RB-WD. ESD in conjunction with RB polymorphism would be useful in prenatal and presymptomatic diagnosis, as well as in carrier detection in informative pedigrees.

Fetal Growth, Obesity, and Atopic Disorders in Adolescence: a Retrospective Birth Cohort Study

BACKGROUNDnDevelopmental status at birth and subsequent obesity have been implicated in the development of childhood atopic dermatitis (AD) and allergic rhinitis (AR).nnnMETHODSnThe current study analysed the cohort data of 74u2009688 junior high school students from a national retrospective birth cohort study in Taiwan. A random 10% sample was selected from singleton livebirths with complete data on the analytical variables of interest. Atopic disorders, including AD and AR, were assessed by questionnaires (International Study of Asthma and Allergies in Childhood). Logistic regression analyses were applied with adjustments for related risk factors.nnnRESULTSnAmong subjects mainly 13-15 years of age, the estimated prevalence was 7.6% for AD and 22.4% for AR. While the role of fetal growth in allergic disorders was less evident, the risk of developing AD and AR were both influenced by a combination of fetal growth status and adolescent body mass index (BMI). Compared with those with normal fetal growth and school-aged BMI, the risk of developing AD increased 64% among adolescents with both restricted fetal growth and high BMI (odds ratio 1.64, 95% confidence intervalu20091.37, 1.97). The risk for this combination was higher than that for either restricted fetal growth or high BMI alone. Nevertheless, the overall interaction between BMI and fetal growth status on atopic disorders did not reach statistical significance.nnnCONCLUSIONSnExcessive weight gain could be an important risk factor related to developing atopic dermatitis and allergic rhinitis during adolescence, especially among infants born small for gestational age.

Low birth weight and environmental tobacco smoke increases the risk of wheezing in adolescents: a retrospective cohort study

BackgroundLow birth weight (LBW) and environmental tobacco smoke (ETS) exposure are each associated with wheezing in children. This study was designed to examine the combined association of LBW and ETS with wheezing.MethodsA retrospective birth cohort analysis linked with a national survey of allergic disorders among 1,018,031 junior high school students in Taiwan (1995–1996) was analyzed. The reported incidence of wheezing (yes or no) and ETS exposure (4 categories: 0, 1–20, 21–40 and greater than or equal to 41 household cigarettes per day) were obtained from validated questionnaires. Multiple logistic regression models were used to assess the associations of interest.ResultsThere were 844,003 (83%) subjects analyzed after the exclusion criteria. LBW was associated with an increased risk of reporting ever wheezing (odds ratio [OR]u2009=u20091.08, 95% confidence interval [CI]u2009=u20091.01–1.16), current wheezing (ORu2009=u20091.09, 95% CIu2009=u20091.00–1.20) and wheezing with exercise (ORu2009=u20091.11, 95% CIu2009=u20091.02–1.21) within the smoke-free cohort. Higher ETS exposure correlated to a higher risk of wheezing (ever, current and with exercise). With ETS exposure, adolescents from the lowest birth weight cohorts were more likely to report wheezing (ever, current and with exercise).ConclusionsETS and LBW each has been related to increasing public health risk for respiratory symptoms among adolescents. Furthermore, LBW may aggravate the risk among those exposed to ETS. LBW, ETS and associated respiratory impairments may deserve special attention as part of a comprehensive environmental health risk assessment directed toward prevention and intervention.