Do centrally obese Chinese with normal BMI have increased risk of metabolic disorders?

BACKGROUND: Body mass index (BMI) and waist circumference are highly correlated. One or the other predicts the metabolic syndromes better, depending on characteristic of the population studied, such as age, gender, and ethnicity. We examined the impact of isolated central obesity, isolated BMI elevation, and the combined type of obesity on metabolic disorders, in order to shed lights on the strategy of obesity screening. METHODS: The study subjects were Chinese aged 20 or above residing in Taiwan. Their data were derived from two large-scale studies: the Nutrition and Health Survey in Taiwan (NAHSIT 1993-1996) and the Cardiovascular Disease Risk Factor Two-township Study (CVDFACTS, 1994-1997). In evaluating the relations between obesity and health risks, the cut-points of BMI (> or =24 kg/m(2) for overweight) and waist circumference (> or =80 cm for women and > or =90 cm for men) recommended by Department of Health in Taiwan for Taiwanese people were used to define various types of obesity. RESULTS: We found that there was a small but nontrivial proportion (1.7% for men and 4.0% for women) of Taiwanese people for whom BMI was in the normal range but their waist circumferences were above normal. These people were at a higher risk of developing metabolic syndromes than those with isolated BMI elevation. Their risks were close to that of the combined type. CONCLUSIONS: In order to screen out high-risk obese individuals, isolated centrally obese subjects should not be overlooked. Therefore, we recommend to assess waist circumference in parallel to, not just sequential to the measurement of BMI in Chinese.

Prevalence and awareness of diabetes and mean fasting glucose by age, sex, and region: results from the Nutrition and Health Survey in Taiwan, 1993-1996.

AIMS: The objective of this study was to evaluate the prevalence and awareness of diabetes mellitus (DM) in Taiwan. METHODS: The Nutrition and Health Survey in Taiwan for people aged > or = 4 years was conducted between 1993 and 1996, using a multistaged, stratified, and clustered sampling scheme. RESULTS: The prevalence of DM, defined by fasting whole blood glucose > or = 6.1 mmol/l or diagnosed DM subjects taking hypoglycaemic drugs, was 3.7% in men > or = 19 years and 6.3% in women. Corresponding to age groups 19-44, 45-64 and > or = 65 years, the prevalence was 1.5%, 7.9% and 7.8% in men and 0.5%, 12.3% and 19.6% in women, respectively. People in mountainous areas and in Peng-Hu islands had the highest prevalence, but the lowest awareness rates among seven survey strata (regions). Women from metropolitan cities had the lowest DM prevalence and body mass index (BMI) values, but the highest rate of DM awareness among all strata. This phenomenon was not apparent in men. The age, sex, and regional patterns of DM prevalence were consistent with those of BMI. CONCLUSIONS: The prevalence of DM in Taiwan in 1993-1996 was relatively high, given a mean BMI of 23 kg/m2 in adults. Gender and regional differences were apparent in DM prevalence and awareness and in mean BMI.

Prevalence, awareness, treatment and control of hypertension in Taiwan: results of Nutrition and Health Survey in Taiwan (NAHSIT) 1993-1996.

The objective of this paper is to describe hypertension status in Taiwan using data from the Nutrition and Health Survey in Taiwan (NAHSIT) 1993-1996, which adopted a clustered stratified multistage sampling scheme. A total of 4838 males and 4876 females aged 4 years and above were interviewed and examined corresponding to a response rate of 74%. Almost all of them (97.5%) had blood pressures measured. The results show that the mean blood pressure of adult males was higher than that of adult females below 45 years of age. After that, the pattern was reversed. When defined by JNC IV criteria (SBP/DBP > or = 160/95 mm Hg or taking antihypertensive drugs), the prevalence was 13% in adult males (> or = 19 years) and 12% in adult females. When defined by JNC VI criteria (SBP/DBP > or = 140/90 mm Hg or taking antihypertensive drugs), the prevalence was 26% in adult males and 19% in adult females. The prevalence in the mountainous area, was the highest among the seven survey strata. Under the JNC IV definition, 43% males and 53% females with hypertension knew their disease status, 31% of males and 45% of females took medicine for it, and 15% of males and 22% of females had their blood pressure under control. Percentages of awareness, treatment, and control were much lower with the JNC V definition, which was introduced toward the end of survey period. People in metropolitan areas had the highest rates of awareness, treatment, control, and compliance to medication.

Hyperuricemia and gout in Taiwan: results from the Nutritional and Health Survey in Taiwan (1993-96).

OBJECTIVE: To evaluate the prevalence of hyperuricemia in Taiwan. METHODS: A multi-stage stratified sampling scheme was used in Nutrition and Health Survey, which was conducted in Taiwan between 1993 and 96. Complete biochemical and questionnaire data for 2754 males and 2953 females aged 4 years and older were included in the analysis. The colorimetric enzymatic method was used to measure plasma uric acid in fasting blood samples. Information on self-reported, physician-diagnosed gout was also obtained. RESULTS: The uric acid values of males were found to reach a peak between the ages of 13 and 18 and decrease slightly after 18. The uric acid values of females were stable before the age of 18, decreasing slightly between 19 and 44 years, and increasing in the mid to older age groups (> or = 45 years). Twenty-six percent of adult males (> or = 19 years) and 22% of older males (> or = 45 years) either had hyperuricemia (serum uric acid > 458.0 microM or 7.7 mg/dl) or were taking medication for it. Seventeen percent of adult females and 23% of older females either had hyperuricemia (serum uric acid > 392.57 microM or 6.6 mg/dl) or were taking medication for it. Both adult males and females in mountainous areas, who were primarily aboriginal, had the highest prevalence of hyperuricemia (> 50%) among the 7 survey areas. Mean body mass index (BMI), alcohol consumption, and prevalence of gout were among the highest in mountainous people compared to all included in the study. Multivariate analysis showed that mountainous area, age and BMI are important factors associated with hyperuricemia in males, whereas mountainous area, Class II townships, and BMI are the factors associated with hyperuricemia in females. CONCLUSIONS: We found a high prevalence of hyperuricemia in Han Chinese in Taiwan despite a lack both of obesity and high alcohol consumption. Mountainous people (mainly aborigines) in Taiwan have an even higher prevalence of hyperuricemia, which cannot be completely explained by obesity and alcohol consumption. Genetic components and other environmental factors may have contributed to this pattern of hyperuricemia.

Undiagnosed diabetes mellitus in Taiwanese subjects with impaired fasting glycemia: impact of female sex, central obesity, and short stature.

AIMS: To study the extent and determinants of undiagnosed diabetes mellitus (DM) in Taiwanese subjects with impaired fasting glycemia (IFG) defined by the newly proposed WHO criteria. METHODS: Oral glucose tolerance tests were carried out for 306 IFG subjects identified from 6632 adult participants of two large scale community-based studies: Nutrition and Health Survey in Taiwan (1993-1996) and the Cardiovascular Disease Two-township Study (1994-1997). Similar protocols were used in these two studies to collect data on glycemic status, anthropometric measurements, and other data used in the present study. RESULTS: Subjects with IFG had a non-trivial undiagnosed diabetes mellitus rate (30% in men and 42% in women) and a high rate of glucose intolerance and undiagnosed DM combined (75% in men and 86% in women). Women with IFG had a 1.6 fold higher risk (p = 0.04) for undiagnosed DM and a 2.1 fold higher risk (p = 0.01) for glucose intolerance and DM when compared to men. There were more women than men with an elevated body mass index in undiagnosed DM patients. Among IFG subjects, undiagnosed DM patients were significantly (p < 0.05) older, more centrally obese and shorter than their normal IFG counterparts, irrespective of gender. In men, height was independent of age and waist circumference in predicting undiagnosed DM (p = 0.037). CONCLUSIONS: A high proportion of impaired glucose tolerance and undiagnosed DM was found in subjects with IFG. Its public health impact should not be overlooked. Central obesity, female sex, and short stature were associated with undiagnosed DM status in IFG subjects.

A model of the real-time correlation of viral titers with immune reactions in antibody-dependent enhancement of dengue-2 infections.

We simultaneously assessed dengue-2 virus (DEN-2) titers by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and immune reactions including interleukin-4 (IL-4), interferon-gamma (IFN-gamma) and prostaglandin E(2) (PGE(2)) production by human mononuclear cells (MNLs) in a model of antibody-dependent enhancement (ADE). We found that DEN-1 immune sera at 1:100 and 1:250, but not those at 1:10 or control sera, enhanced DEN-2 infections in human MNLs as assessed by the fluorogenic RT-PCR technique. The enhanced profiles of DEN-2 infections determined by the RT-PCR in 6 h were reproducible by the standard plaque-forming unit (PFU) measurement established after 7 days. The ADE-enhanced DEN-2 titers determined by the RT-PCR were 5.5-33-fold higher than those detected by PFU assay, suggesting that total virions during infections were much higher than the viable ones detected by PFU assay. MNLs in response to DEN-2 infections had higher IFN-gamma and PGE(2) production. However, the enhancement of DEN-2 infections by DEN-1 immune sera in MNLs was not associated with further enhancement of IFN-gamma production. In contrast, the presence of subneutralizing DEN-1 immune sera that enhanced DEN-2 infections also enhanced PGE(2) but not IL-4 production. The results of this study suggest that ADE of DEN-2 infections associated with induction of immunosuppressive mediators such as PGE(2) and IL-4 can be simultaneously assessed in a real-time fashion.

Antibody-dependent enhancement of heterotypic dengue infections involved in suppression of IFNgamma production.

Antibody-dependent enhancement has been implicated in some outbreaks of epidemic dengue hemorrhagic fever, however, the mechanism of antibody-dependent enhancement is not well known. This study was conducted to investigate the cross-protection and cross-enhancement of dengue-2 virus infections by dengue-1 immune sera. It was found that dengue-1 immune sera at 1:5 dilution (n = 12) could neutralize dengue-2 infections in BHK-21 cells, as assessed by a standard plaque-reduction neutralization assay. Two-thirds of the dengue-1 immune sera at 1:25 dilution demonstrated neutralizing effects for dengue-2 infections, whereas, non-immune sera revealed no neutralization for dengue-2 infections in BHK-21 cells. Human mononuclear leukocytes in response to dengue-2 infections elicited a T cell helper 1 (Th1) response revealing induction of IFNgamma but not IL-4 production. Dengue-1 immune sera did not neutralize dengue-2 infections in mononuclear leukocytes. Subneutralizing titers of dengue-1 immune sera at 1:250, but not at 1:10 dilution, enhanced dengue-2 infections in mononuclear leukocytes (1.2 +/- 0.7 x 10(4) vs. 2.8 +/- 0.3 x 10(2) PFU/ml). The enhancement of dengue-2 infections in mononuclear leukocytes by dengue-1 immune sera at 1:250 was associated with an increase in the lymphocyte proliferation index, and a decrease in IFNgamma production (56 +/- 24 vs. 12 +/- 3 pg/ml). The addition of IFNgamma (0.1 microg/ml) suppressed significantly the antibody-dependent enhancement induced by dengue-1 immune sera, whereas the presence of anti-IFNgamma F(ab)2 antibody augmented the antibody-dependent enhancement effect. Results from this study suggest that suppression of Th1 response may be involved in the antibody-dependent enhancement of heterotypic dengue infections. Better regulation of Th1/Th2 reactions may be useful for prevention of heterotypic immune enhancement of dengue infections.

Common variable immunodeficiency with mosaic trisomy 8: report of one case.

This case study reported a 17-year-old female of common variable immunodeficiency (CVID) associated with bronchiectasis, pernicious anemia and mosaic trisomy 8. Clinically this patient presented with recurrent sinopulmonary infections, intractable diarrhea, macrocytic anemia, and primary amenorrhea. Immunological tests showed pan-hypogammaglobulinemia and a decrease of peripheral blood B cells (4%) and CD4+ cells (25%). Lymphoproliferative responses to mitogen (PHA) and specific antigen (BCG) were profoundly impaired in the patient in comparison to those in control. Production of interleukin 4 (IL-4) and gamma interferon (IFN-gamma) in the in vitro lymphoproliferation was also profoundly depressed. Pernicious anemia demonstrated by larger MCV (112.9 fl) and hyper-segmental granulocytes on peripheral blood smear responded to parental administration of vitamin B12. Interestingly, she had a mosaic trisomy 8 in peripheral blood mononuclear cells but normal 46XX karyotype in the bone marrow cells. To our knowledge, this is the first case of CVID associated with mosaic trisomy 8 reported in the literature. As the case exemplifies, CVID should be considered when the physicians evaluate the patient presenting with recurrent sinopulmonary infections, diarrhea, malnutrition, and pernicious anemia. It requires further study to explore whether the genes in the chromosome 8 are linked to CVID.

Testing a zone plate with a grating interferometer.

The physical theory, of testing optics by the Ronchi sine grating interferometer is developed. In the experiment a sine grating splits the third-order wavefront of the zone plate under test into three displaced wavefronts, which then interfere with one another to form interference fringes. The intensity distribution of the interference pattern can be recorded for various positions of the sine grating. By subtracting the contribution of the inherent diffractive aberration of the sine grating, the value of the spherical aberration associated with the third-order wavefront of the zone plate under test can be determined. Theory and experiment are compared.