Biomedical subjects

Wei Chen

Publications and source records attributed to Wei Chen.

At least 253 records · Page 14Linked to original sources

PubMed2005

G-6A polymorphism of the angiotensinogen gene and its association with left ventricular mass in asymptomatic young adults from a biethnic community: the Bogalusa Heart Study.

BACKGROUND: Angiotensinogen (AGT), the precursor of angiotensin II and a rate limiting factor in the renin-angiotensin system, is implicated in left ventricular hypertrophy, as angiotensin II is a potent stimulator of cardiac growth. A genetic variant (G-6A) in the proximal promoter region of the AGT gene may be particularly important for changes in left ventricular mass (LVM). However, previous findings associating this variant with LVM among relatively older adults with cardiovascular morbidity are inconsistent and contradictory. METHODS: This study examined the effect of G-6A polymorphism on LVM in a biethnic (African American and white), community-based sample of 362 asymptomatic younger adults (mean age 32.5 years, 71% white, 39% male). Two-dimensional M-mode echocardiography was used to assess LVM, and the indexation of LVM for height(2.7) (LVMI) was used to adjust for body size. RESULTS: The frequency of the variant A(-6) allele was higher in subjects of African American than in white ethnicity (0.819 v 0.439, P < .0001), with carriers (GA+AA) representing 97.0% of African American as compared to 66.6% of white subjects. After adjusting for age, ethnicity (for total sample), gender, body mass index, systolic BP, and homeostasis model assessment index of insulin resistance, mean levels for both LVM and LVMI showed a significant decreasing trend with increasing gene dosage of the A(-6) allele in white subjects, African American subjects, and the total sample. CONCLUSIONS: These results indicate that the A(-6) allele frequency differs markedly between African Americans and white individuals, and that the variant allele modulates LVM and LVMI in a beneficial manner in asymptomatic young adults of white and African American ethnicities.

Adult↗

PubMed2005

FLT3 ligand administration after hematopoietic cell transplantation increases circulating dendritic cell precursors that can be activated by CpG oligodeoxynucleotides to enhance T-cell and natural killer cell function.

Dendritic cells (DCs) are key effectors in innate immunity and play critical roles in triggering adaptive immune responses. FLT3 ligand (FLT3-L) is essential for DC development from hematopoietic progenitors. In a phase I clinical trial, we demonstrated that immunotherapy with subcutaneous injection of FLT3-L is safe and well tolerated in cancer patients recovering from autologous hematopoietic cell transplantation (HCT). FLT3-L administration significantly increased the frequency and absolute number of blood DC precursors without affecting other mature cell lineages during the 6-week course of FLT3-L therapy. After 14 days of FLT3-L administration, the number of blood CD11c + DCs, plasmacytoid DCs (PDCs), and CD14 + monocytes increased by 5.3-, 2.9-, 3.8-fold, respectively, and was maintained at increased levels throughout FLT3-L therapy. FLT3-L-increased blood DCs in HCT patients were immature and had modest enhancing effects on in vitro T-cell proliferation to antigens and natural killer (NK) cell function. The addition of type B CpG oligodeoxynucleotides (ODNs) to peripheral blood mononuclear cells obtained from HCT patients receiving FLT3-L therapy induced rapid maturation of both CD11c + DCs and PDCs and enhanced T-cell proliferative responses. In addition, CpG ODN induced potent activation of NK cells from FLT3-L-treated patients with increased surface CD69 expression and augmented cytotoxicity. CpG ODN-induced activation of NK cells was primarily via an indirect mechanism through PDCs. These findings suggest that FLT3-L mobilization of DC precursors followed by a specific DC stimulus such as CpG ODN may provide a novel strategy to manipulate antitumor immunity in patients after HCT.

Adult↗

PubMed2005

Formation of MacroH2A-containing senescence-associated heterochromatin foci and senescence driven by ASF1a and HIRA.

In senescent cells, specialized domains of transcriptionally silent senescence-associated heterochromatic foci (SAHF), containing heterochromatin proteins such as HP1, are thought to repress expression of proliferation-promoting genes. We have investigated the composition and mode of assembly of SAHF and its contribution to cell cycle exit. SAHF is enriched in a transcription-silencing histone H2A variant, macroH2A. As cells approach senescence, a known chromatin regulator, HIRA, enters PML nuclear bodies, where it transiently colocalizes with HP1 proteins, prior to incorporation of HP1 proteins into SAHF. A physical complex containing HIRA and another chromatin regulator, ASF1a, is rate limiting for formation of SAHF and onset of senescence, and ASF1a is required for formation of SAHF and efficient senescence-associated cell cycle exit. These data indicate that HIRA and ASF1a drive formation of macroH2A-containing SAHF and senescence-associated cell cycle exit, via a pathway that appears to depend on flux of heterochromatic proteins through PML bodies.

Amino Acid Sequence↗

PubMed2005

A negative feedback mechanism involving nitric oxide and nuclear factor kappa-B modulates endothelial nitric oxide synthase transcription.

Nuclear factor kappa B (NFkappaB), commonly a proinflammatory transcription factor, is responsible for increasing transcription of the endothelial cell nitric oxide synthase (eNOS) in response to laminar shear stress. Nitric oxide (NO) production can be stimulated by shear, and NO is known to inhibit NFkappaB activation. We hypothesized that this inhibitory action of NO on NFkappaB activation serves as a negative feedback to inhibit NFkappaB activity and eNOS transcription. Exposure of bovine aortic endothelial cells to laminar shear stimulated steady state eNOS mRNA expression and eNOS promoter activity as measured using an eNOS promoter/CAT construct. These effects of shear were enhanced by the NOS inhibitor l-NAME and decreased by the NO-donor DPTA-NO by 30-50%. The NFkappaB inhibitor panepoxydone prevented the increase in eNOS mRNA caused by shear confirming a role of NFkappaB in this response. Shear stress stimulated a transient (30 min) nuclear translocation of the NFkappaB subunit p50. Treatment with l-NAME increased binding of the NFkappaB subunit p50 to consensus oligonucleotide-coated microtiter plates, while having only minimal effect on binding of p65, strongly suggesting that nitric oxide mainly inhibits p50 activation. Using the biotin switch method, we found that shear stress stimulates p50 nitrosylation and this was prevented by l-NAME. Moreover, transfection of endothelial cells with a vector encoding the C62S p50, a variant with a point mutation of the nitrosylation site C62, markedly increased nuclear translocation of p50 and doubled eNOS mRNA expression under shear stress compared to that observed in cells transfected with wild-type p50. We conclude that this interaction between shear, NFkappaB activation, NO production and NFkappaB inhibition represents a classical negative feedback loop, which prevents sustained activation of NFkappaB. In the absence of NO, shear stimulation of NFkappaB and eNOS transcription are enhanced. Our findings emphasize the critical role of NO in modulation of the endothelial cell inflammatory state. Several common diseases, including hypercholesteremia, hypertension and diabetes, are associated with eNOS dysfunction. Under these conditions, decreased NO availability may result in sustained activation of NFkappaB in response to shear and unrestrained endothelial inflammation.

Animals↗

PubMed2005

Effects of a 0.9% sodium chloride ophthalmic solution on the ocular surface of symptomatic contact lens wearers.

BACKGROUND: Ocular surface-related discomfort is the main reason for stopping contact lens wear. We carried out a study to evaluate the efficacy of preservative-free artificial tears containing 0.9% sodium chloride on ocular surface signs and symptoms in contact lens wearers experiencing discomfort and its possible influence on the duration of contact lens wear. METHODS: We studied 49 contact lens wearers experiencing discomfort who had normal results of slit-lamp biomicroscopy, a fluorescein tear film break-up time (BUT) of 10 seconds or more, and wetting greater than 5 mm in 5 minutes on the Schirmer 1 test with and without anesthesia. Twenty-nine subjects (16 men and 13 women with a mean age of 32.5 years [standard deviation (SD) 8.7 years]) received one instillation of the 0.9% sodium chloride solution four times daily in the lower conjunctival fornix for 21 days. Twenty subjects (12 men and 8 women with a mean age of 35.1 [SD 6.2] years) received no drops and served as a control group. The overall comfort and duration of contact lens wear, results of tear film analysis and adverse events were recorded on days 7 and 21. Patients rated their symptoms (while not receiving any medications or hydrating solutions) on a 100-mm visual analogue scale with "Excellent (lenses not felt)" at the left and "Very uncomfortable (lenses cause irritation or discomfort)" at the right. Measurement of corrected visual acuity, slit-lamp examination, determination of the tear film BUT, the Schirmer 1 test with and without anesthesia, and assessment of the colour and surface of the lens were performed at baseline and at day 21. We analysed the data for the more uncomfortable eye or, if the eyes were equally uncomfortable, the right eye. RESULTS: Significant lessening of ocular discomfort was observed in the treatment group during the study: the mean rating on the visual analogue scale at baseline was 60.2 mm (SD 12.7 mm), compared with 35.8 mm (SD 18.0 mm) at day 21 (p < 0.001, Student's t test). The duration of contact lens wear was significantly longer at day 21 than at baseline (7.0 [SD 2.6] hours vs. 6.4 [SD 2.6] hours, p < 0.05, Student's t test), and the proportion of subjects with conjunctival hyperemia was significantly lower at day 21 (48.3% vs. 82.8%, p < 0.05, chi2 test). No statistically significant changes were observed in tear film BUT, results of the Schirmer 1 test, corneal punctate staining by fluorescein or results of tear film analysis. The treatment was well tolerated by all patients. No significant differences in any of the variables studied were observed in the control group. INTERPRETATION: Treatment with a preservative-free 0.9% sodium chloride ophthalmic solution reduced ocular surface discomfort and extended the duration of contact lens wear without interfering with the tear film or contact lens materials. Long-term studies are needed to confirm the role of this solution in reducing discomfort experienced by contact lens wearers.

Adult↗

PubMed2005

Role for hedgehog signaling in hepatic stellate cell activation and viability.

Hepatic stellate cells (HSC) have a complex phenotype that includes both neural and myofibroblastic features. The Hedgehog (Hh) pathway has been shown to direct the fate of neural and myofibroblastic cells during embryogenesis and during tissue remodeling in adults. Therefore, we hypothesized that Hh signaling may regulate the fate of HSC in adults. In this study, we find that freshly isolated stellate cells from adult Patched-lacZ transgenic mice exhibit beta-galactosidase activity, indicating Hh pathway activity. Transcripts of Hh ligands, the Hh pathway receptor, and Hh-regulated transcription factors are expressed by stellate cells from mice, rats, and humans. Transfection experiments in a cell line using a Hh-inducible luciferase reporter demonstrate constitutive Hh pathway activity. Moreover, neutralizing antibodies to Hh increase apoptosis, while viability is restored by treatment with Hh ligand. In vitro treatment of primary stellate cells with cyclopamine (Cyc), a pharmacologic inhibitor of the Hh pathway, inhibits activation and slightly decreases cell survival, while a single injection of Cyc into healthy adult mice reduces activation of HSC by more than 50% without producing obvious liver damage. Our findings reveal a novel mechanism, namely the Hh pathway, that regulates the activation and viability of HSC.

Animals↗

PubMed2005

Utility of childhood BMI in the prediction of adulthood disease: comparison of national and international references.

OBJECTIVE: To determine whether the U.S. Centers for Disease Control and Prevention (CDC; CDC Reference) or International Obesity Task Force (IOTF; IOTF Reference) BMI cut-off points for classifying adiposity status in children are more effective at predicting future health risk. RESEARCH METHODS AND PROCEDURES: The sample (N=1709) included 4- to 15-year-old (at baseline) boys and girls from the Bogalusa Heart Study. Overweight and obesity status were determined using both the CDC Reference and IOTF Reference BMI cut-off points at baseline. The ability of childhood overweight and obesity, determined from the two BMI classification systems, to predict obesity and metabolic disorders in young adulthood (after a 13- to 24-year follow-up) was then compared. RESULTS: Independently of the classification system employed to determine adiposity based on childhood BMI, the odds of being obese and having all of the metabolic disorders in young adulthood were significantly (p<0.05) higher in the overweight and obese groups by comparison with the nonoverweight groups. Childhood overweight and obesity, determined by both the CDC Reference and IOTF Reference, had a low sensitivity and a high specificity for predicting obesity and metabolic disorders in young adulthood. Overweight and obesity as determined by the CDC Reference were slightly more sensitive and slightly less specific than the corresponding values based on the IOTF Reference. DISCUSSION: Overweight and obesity during childhood, as determined by both the CDC and IOTF BMI cut-off points, are strong predictors of obesity and coronary heart disease risk factors in young adulthood. The differences in the predictive capacity of the CDC Reference and IOTF Reference are, however, minimal.

Adult↗

PubMed2005

Interactive effects between polymorphisms in the beta-adrenergic receptors and longitudinal changes in obesity.

We assessed interactions between polymorphisms in the beta-adrenergic receptor genes and longitudinal changes in obesity from childhood to adulthood using longitudinal data collected over a 24-year period from 1973 to 1996. Sex- and age-stratified analyses using random coefficients models were used to examine gene-gene interaction effects on obesity measures in 1179 African-American and white men and women (71% white, 57% women). Suggestive evidence for an interaction (p = 0.022) between the beta1- and beta2-adrenergic receptors was observed in men for longitudinal change in BMI. Men with Gly/Gly genotypes for both the beta1 and beta2 receptors showed significant increases (approximately 0.6%/yr) in BMI from childhood to adulthood. Women showed suggestive evidence for an interaction (p = 0.035) between the beta1- and beta3-adrenergic receptors for change over time in BMI. Women with Gly/Gly genotypes at the beta1-receptor and carrying at least one beta3-Arg allele showed notable increases in BMI. The regulation of lipolysis and development of obesity differ markedly between men and women and may be influenced by genetic polymorphisms, which contribute to the efficiency of the beta-adrenergic receptors, and hormonal effects on adrenergic receptor activity.

Black People↗

PubMed2005

Changes in prognosis after the first postoperative complication.

BACKGROUND: Postoperative complications are common in the Medicare population, yet no study has formally quantified the change in prognosis that occurs after a broad range of first complications. OBJECTIVE: We sought to estimate the relative severity of 24 first postoperative complications. RESEARCH DESIGN: We undertook a multivariate matched, population-based, case-control study of death after surgery in a sample of 1362 Pennsylvania Medicare patients. SUBJECTS: Cases (681 deaths) were selected randomly using claims from 1995-1996. Models were developed to scan all Pennsylvania claims, looking for similar controls that did not die. MEASURES: Charts were abstracted, complications identified, and models were constructed to estimate the odds of dying after any 1 of 24 first postoperative complications. RESULTS: The odds of dying within 60 days increased 3.4-fold (95% confidence interval [CI] 2.5-4.7) in patients with complications as compared with those without complications. A first complication of respiratory compromise was associated with a 7.2-fold increase in the odds of dying (95% CI 4.5-11.6). The first complications of pneumonia or congestive heart failure were associated with, respectively, 5-fold (95% CI 2.1-12.1) and 5.1-fold (2.3-11.1) increases in odds of dying as compared with no complication. CONCLUSIONS: First complications after surgery, even seemingly mild ones, may radically alter the patient's risk of death. First complications often begin the cascade of complications that end in death. Caregivers should consider the first complication as a timely signal of a changed clinical situation demanding a reevaluation of the patient's care. Researchers may use these estimates to determine the relative severity of a broad range of first or early complications.

Aged↗

PubMed2005

Endovascular stent placement for the treatment of nutcracker phenomenon in three pediatric patients.

Invasive treatment for nutcracker syndrome is controversial, especially in patients with a pediatric onset. Most patients are treated conservatively for a relatively long time, but severe hematuria with an intermittent exacerbation remained unchanged. Three pediatric patients presented with hematuria associated with or without mild proteinuria and were diagnosed as having nutcracker syndrome. The authors performed self-expandable endovascular stent placement across the left renal vein in these pediatric patients. Severe gross hematuria completely subsided after treatment and no serious complications are noted during 2- or 3-year follow-up; moreover, all patients have good physical development.

Adolescent↗

PubMed2005

Preoperative antibiotics and mortality in the elderly.

OBJECTIVE AND BACKGROUND: It is generally thought that the use of preoperative antibiotics reduces the risk of postoperative infection, yet few studies have described the association between preoperative antibiotics and the risk of dying. The objective of this study was to determine whether preoperative antibiotics are associated with a reduced risk of death. METHODS: We performed a multivariate matched, population-based, case-control study of death following surgery on 1362 Pennsylvania Medicare patients between 65 and 85 years of age undergoing general and orthopedic surgery. Cases (681 deaths within 60 days from hospital admission) were randomly selected throughout Pennsylvania using claims from 1995 and 1996. Models were developed to scan Medicare claims, looking for controls who did not die and who were the closest matches to the previously selected cases based on preoperative characteristics. Cases and their controls were identified, and charts were abstracted to define antibiotic use and obtain baseline severity adjustment data. RESULTS: For general surgery, the odds of dying within 60 days were less than half in those treated with preoperative antibiotics within 2 hours of incision as compared with those without such treatment: (odds ratio = 0.44; 95% confidence interval, 0.32-0.60), P < 0.0001). For orthopedic surgery, no significant mortality reduction was observed (OR = 0.85; 95% confidence interval, 0.54-1.32; P < 0.464). INTERPRETATION: Preoperative antibiotics are associated with a substantially lower 60-day mortality rate in elderly patients undergoing general surgery. In patients who appear to be comparable, the risk of death was half as large among those who received preoperative antibiotics.

Age Factors↗

PubMed2005

Identification and preliminary characterization of cell-wall-anchored proteins of Staphylococcus epidermidis.

Staphylococcus epidermidis is a ubiquitous human skin commensal that has emerged as a major cause of foreign-body infections. Eleven genes encoding putative cell-wall-anchored proteins were identified by computer analysis of the publicly available S. epidermidis unfinished genomic sequence. Four genes encode previously described proteins (Aap, Bhp, SdrF and SdrG), while the remaining seven have not been characterized. Analysis of primary sequences of the Staphylococcus epidermidis surface (Ses) proteins indicates that they have a structural organization similar to the previously described cell-wall-anchored proteins from S. aureus and other Gram-positive cocci. However, not all of the Ses proteins are direct homologues of the S. aureus proteins. Secondary and tertiary structure predictions suggest that most of the Ses proteins are composed of several contiguous subdomains, and that the majority of these predicted subdomains are folded into beta-rich structures. PCR analysis indicates that certain genes may be found more frequently in disease isolates compared to strains isolated from healthy skin. Patients recovering from S. epidermidis infections had higher antibody titres against some Ses proteins, implying that these proteins are expressed during human infection. Western blot analyses of early-logarithmic and late-stationary in vitro cultures suggest that different regulatory mechanisms control the expression of the Ses proteins.

Bacterial Proteins↗

PubMed2005

An inverted-microstrip resonator for human head proton MR imaging at 7 tesla.

As an extension of the previously developed microstrip transmission line (MTL) RF coil design, a high-frequency RF volume coil using multiple inverted MTL (iMTL) resonators for human head imaging at high magnetic field strength of 7 tesla (T) is reported. Compared to conventional MTL resonators, iMTL resonators can operate at higher frequency with lower losses and, thus, are suitable for designs of high-frequency RF volume coils with large coil size for human MR imaging and spectroscopy at high fields. An approach using capacitive terminations was analyzed and applied to the design of the iMTL volume coil for improving RF field homogeneity and broadening frequency-tuning range. A performance-comparison study was conducted between the prototype iMTL volume coil and a custom-built TEM volume coil at 7 T. The iMTL volume coil presents a comparable SNR and intrinsic B1 homogeneity to the TEM volume coil. Phantom and the human head images acquired using the iMTL volume coil are also presented. The proposed iMTL volume coil provides an efficient and alternative solution to design high-frequency and large-size volume coils for human MR applications at very high fields.

Brain↗

PubMed2005

B-cell responses in patients who have recovered from severe acute respiratory syndrome target a dominant site in the S2 domain of the surface spike glycoprotein.

Severe acute respiratory syndrome (SARS) is a recently emerged infectious disease caused by a novel strain of coronavirus. Examination of the immune responses of patients who have recovered from SARS should provide important information for design of a safe and effective vaccine. We determined the continuous viral epitopes targeted by antibodies in plasma samples from convalescent SARS patients through biopanning with a vast M13 phage display dodecapeptide library. These epitopes converged to very short peptide fragments, one on each of the structural proteins spike and nucleocapsid and the nonstructural proteins 3a, 9b, and nsp 3. Immunoassays found that most of the patients who had recovered from SARS developed complementary antibodies to the epitope-rich region on the spike S2 protein, indicating that this is an immunodominant site on the viral envelope comprising the spike, matrix, and small envelope glycoproteins. These S2-targeting antibodies were shown to effectively neutralize the coronavirus, indicating that they provided protective immunity to help the patients recover from the viral infection. These results suggest that the SARS coronavirus might have an antigenic profile distinct from those of other human or animal coronaviruses. Due to the tested safety and protective effects of the convalescent-phase serological antibodies, identification of their complementary antigens may enable the design of an epitope-based vaccine to prevent potential antibody-mediated immunopathology.

Adult↗

PubMed2005

Fabrication and luminescence of ZnS:Mn2+ nanoflowers.

Visually striking nanoflowers composed of ZnS:Mn2+ nanoparticles are prepared and characterized. The configurations of these fractal structures are very sensitive to both the pH values of the particle solutions from which they are precipitated and the substrates on which they are deposited. At pH 2.2, the fractal structures resemble trees without leaves; at pH 7.7, they are tree-like with four arms and at pH 11.0 they resemble trees with six arms. High resolution transmission microscopy reveals that the nanoflowers are composed of ZnS:Mn2+ nanoparticles of 2-5 nm in size. X-ray photoelectron spectral data indicate that the sample compositions of nitrogen, chlorine, and sulfur vary gradually with pH values of the solutions. These changes may have an impact on both the fractal configuration and the luminescence properties. The emission spectra of the particle solutions at pH values of 2.2 and 11.0 are similar with the emission maximum at 475 nm. As the pH value approaches 7.7, the emission spectral maximum shifts to longer wavelengths. At a pH value of 7.7, the emission peak wavelength is the reddest, 520 nm. The emission peak of the nanoflowers at a pH value of 9.3 is 510 nm, while the emission spectrum of the nanoflowers at 5.2 has two peaks at 500 nm and 440 nm, respectively. These blue-green emissions are attributed to defects and are the dominant luminescence from the nanoflowers. The emission from Mn2+ dopant is only observed in the delayed spectra of the fractal solid samples.

Crystallization↗

PubMed2005

Synthesis and luminescence of ZnMgS:Mn2+ nanoparticles.

Efficient green emission from ZnMgS:Mn2+ nanoparticles prepared by co-doping Mg2+ and Mn2+ ions into ZnS lattices has been observed. The synthesis is carried out in aqueous solution, followed by a post-annealing process, thus showing the features of less complexity, low cost, and easy incorporation of dopants. In comparison with the emission of ZnS:Mn2+ nanoparticles, which is located generally around 590 nm, the photoluminescence of ZnMgS:Mn2+ nanoparticles is blue-shifted by 14 nm in wavelength, leading to the enhanced green emission. The X-ray diffraction, electron spin resonance, and pressure dependent photoluminescence measurements suggest that the change of the crystal field caused by Mg2+ ionic doping and the lower symmetry in the nanoparticles may account for the blue-shift of the photoluminescence. The ZnMgS:Mn2+ nanoparticles with 1% Mn2+ doping exhibit the strongest luminescence, which could potentially meet the requirements for the construction of green light emitting diodes.

Crystallization↗

PubMed2005

Electroconformational denaturation of membrane proteins.

Because of high electrical impedance of cell membrane, when living cells are exposed to an external electric field, the field-induced voltage drops will mainly occur on the cell membrane. In addition to Joule heating damage and electroporation of the cell membrane, the electric field-induced supraphysiological transmembrane potential may inevitably damage the membrane proteins, especially the voltage-dependent membrane proteins. That is because the charged particles in the amino acid of the membrane proteins and, in particular, the voltage-sensors in the voltage-dependent membrane proteins are vulnerable to the membrane potential. An intensive, brief electric shock may induce electroconformational damage or denaturation in the membrane proteins. As a result, the cell functions are significantly reduced. This electric field-induced denaturation in the membrane proteins strongly suggests a new underlying mechanism involved in electrical injury.

Animals↗

PubMed2005

Combined influence of body mass index and waist circumference on coronary artery disease risk factors among children and adolescents.

OBJECTIVES: In adult populations, it is recognized widely that waist circumference (WC) predicts health risk beyond that predicted by BMI alone; current recommendations for adults are that a combination of BMI and WC be used to classify obesity-related health risk. For children and adolescents, however, little is known about the combined influence of BMI and WC on health outcomes. The objectives of this study were to determine whether BMI and WC predict coronary artery disease (CAD) risk factors independently for children and adolescents and to assess the clinical utility of using WC in combination with BMI to identify CAD risk. METHODS: Subjects included 2597 black and white, 5- to 18-year-old, male and female youths. Outcome measures included 7 CAD risk factors. In the first analysis step, BMI and WC were used as continuous variables to predict CAD risk factors. In the second analysis step, participants were placed into normal-weight, overweight, and obese BMI categories and, within each BMI category, CAD risk factors were compared for groups with low and high WC values. RESULTS: When BMI and WC were included in the same regression model to predict CAD risk factors, the added variance above that predicted by BMI or WC alone was minimal, which indicated that BMI and WC did not have independent effects on the risk factors. For example, for systolic blood pressure, BMI alone explained 7.3% of the variance, WC alone explained 7.7% of the variance, and the combination of BMI and WC explained 8.1% of the variance. When BMI and WC values were categorized with a threshold approach, WC provided information on CAD risk beyond that provided by BMI alone, particularly when the categories were used to predict elevated CAD risk factor levels. For instance, in the overweight BMI category, the high-WC group was approximately 2 times more likely to have high triglyceride levels, high insulin levels, and the metabolic syndrome, compared with the low-WC group. CONCLUSION: These findings provide some evidence that a combination of BMI and WC should be used in clinical settings to evaluate the presence of elevated health risk among children and adolescents.

Adolescent↗