Abstract P5-11-08: SRA/SRAP contributes to TGF-b1 induced cell motility in cancer cells

The steroid receptor RNA activator gene (SRA1) is a particularly intriguing genetic system in that both the corresponding RNA (SRA) and protein (SRAP) have been proven to be functional. Accumulated evidence overall suggests that both molecules act as distinct co-regulators of transcription, housed in ribonucleo-protein complexes able to positively or negatively regulate the activity of multiple transcription factors including -but not limited to- several nuclear receptors, MyoD and DAX-1.

A role for SRA/SRAP deregulation during breast tumorigenesis has been suggested. Indeed, not only do these molecules regulate the activity of both Estrogen Receptors, these major players in breast cancer etiology, but it has also been shown that SRA RNA is more highly expressed in breast tumors than in normal tissue, and that high levels of SRAP correlated to poorer survival in specific subsets of breast cancer patients.

In order to identify the genes and pathways regulated by SRA/SRAP, we performed deep sequencing of transcriptomes from MDA-MB-231 cells depleted of these molecules following RNA interference. The expression of 149 genes was consistently and significantly altered in four independent experiments comparing control RNAi vs SRA RNAi. Interestingly, cluster analysis using Ingenuity software defined a subset of genes (23 out of 149) directly associated with cell movement. Among them figured TGFBR1 (ALK5), a cell surface receptor-kinase mediating TGF-b signalling and a known promoter of cell motility in breast cancer cells.

We have now confirmed by quantitative PCR analysis a 40% decrease, upon SRA/SRAP depletion, of TGFBR1 mRNA expression in MDA-MB-231 cells as well as in other breast (MCF7, T5) and non-breast (Hela) cancer cell lines. Consistent with this decrease a drop to 60% of the basal TGFBR1 protein expression is seen by Western blot when MDA-MB-231 cells are depleted of SRA/SRAP. Western blot analyses also revealed that phosphorylation of several SMAD molecules, downstream effectors of TGFBR1 activation by TGF-β1, is impaired in the absence of SRA/SRAP in both MDA-MB-231 and Hela cells. This suggests that SRA/SRAP could potentially regulate TGF beta induced cell motility.

Using migration cell assays, we have now confirmed that upon TGF-β1 treatment for 6 hours, SRA/SRAP depleted cells had a significant decrease in migration as compared to control cells. Accordingly, live cell migration assays generated by a time-lapse videomicroscopy system, showed an increased track length and speed in both Hela and 231 cells over-expressed SRAP upon 10 h TGF-β1 treatment.

Taken together, these data suggest a cross-talk between SRA/SRAP and TGF-β signalling and induced cell motility.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-11-08.

Abstract P1-06-05: Expansion of tumor initiating cells is mediated by tumor microenvironment in breast cancer metastasis

Background: Breast cancer metastasis which ultimately results in breast cancer death, is an event believed to be initiated by the migration of tumor initiating cells (TIC) from the primary tumor to niches for micrometastatic disease. Recent data suggests the tumor microenvironment promotes TIC. The clinical relevance of secreted factors from the microenvironment on TIC surrogate, mammosphere (MS) formation and MS sensitivity to drug therapy was investigated using breast cancer patient fluids inherently conditioned by the tumor microenvironment: post-operative seromas and malignant pleural effusions.

Methods: Fluids from 48 patients with breast cancer (15 seromas and 33 pleural effusions) and mesenchymal stem cells (MSC) from healthy donors were collected on IRB approved protocols. Cellular components were eliminated from patient-derived fluids using density-gradient centrifugation. MSC conditioned media (MSC-CM) was collected from 3D cultures of primary MSC. Luminex multiplex array platform was used to characterize 79 cytokine and growth factor components of all fluids. In addition, MSC-CM and patient-derived fluids were added to cultures of breast cancer cell lines: MCF-7, an estrogen receptor (ER)-positive cell line; SUM149, a triple-negative inflammatory breast cancer cell line; and SUM159, a triple-negative metaplastic breast cancer cell line and MS forming efficiency was examined.

Results: Our results show that pleural effusions and seromas are enriched for factors also secreted by MSC such as MCP-1, GRO, IL-6, and VEGF-A. We found remarkable similarities regarding the cytokines and growth factors profile in pleural effusions and seromas. Both patient-derived fluids have comparable amount of Angiopoetin-2, Leptin, TNF-beta, VEGF, IL-2, IL-3, IL-4 and IL-10. EGF, TNF-alpha, IL-1, IL-6, IL-8 and IL-16 were significantly different between pleural effusions and seromas. Seroma fluid from bilateral drains in a patient with an invasive cancer and a contralateral benign mastectomy had very similar cytokine concentrations. Moreover, MSC-CM and pleural fluids from ER-positive and ER-negative patients increased the MS formation efficiency of both triple-negative cell lines while seroma fluids from ER-positive and ER-negative patients increased the MS formation efficiency of ER-positive cell line MCF-7. Finally, we evaluated the impact of a panel of drugs (simvastatin, pravastatin and erlotinib) on cell cultures grown with MSC-CM and patient-derived fluids. We found that the effect of chemotherapies on MS formation can be attenuated by patient-derived fluids.

Conclusions: Seroma and pleural effusion fluids from breast cancer patients have similar cytokine profiles, change MS formation efficiency of standard breast cancer cell models, and mediate sensitivity to therapy. Here we demonstrate that host and microenvironmental factors are critical for determining resistance to therapy and may be independent of obvious tumor related factors. Future studies will investigate the prognostic implications of factors that promote TIC survival in the fluid tumor microenvironment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-06-05.

Organochlorine pesticides in the atmosphere and surface water from the equatorial Indian Ocean: enantiomeric signatures, sources, and fate

Nineteen pairs of gaseous and surface seawater samples were collected along the cruise from Malaysia to the south of Bay of Bengal passing by Sri Lanka between April 12 and May 4, 2011 on the Chinese research vessel Shiyan I to investigate the latest OCP pollution status over the equatorial Indian Ocean. Significant decrease of α-HCH and γ-HCH was found in the air and dissolved water phase owing to global restriction for decades. Substantially high levels of p,p'-DDT, o,p'-DDT, trans-chlordane (TC), and cis-chlordane (CC) were observed in the water samples collected near Sri Lanka, indicating fresh continental riverine input of these compounds. Fugacity fractions suggest equilibrium of α-HCH at most sampling sites, while net volatilization for DDT isomers, TC and CC in most cases. Enantiomer fractions (EFs) of α-HCH and o,p'-DDT in the air and water samples were determined to trace the source of these compounds in the air. Racemic or close to racemic composition was found for atmospheric α-HCH and o,p'-DDT, while significant depletion of (+) enantiomer was found in the water phase, especially for o,p'-DDT (EFs = 0.310 ± 0.178). 24% of α-HCH in the lower air over the open sea of the equatorial Indian Ocean is estimated to be volatilized from local seawater, indicating that long-range transport is the main source.

Mercury profiles in surface sediments from ten bays along the coast of Southern China

Spatial and temporal variations of mercury (Hg) were investigated from ten representative bays along the coast of Southern China. The total Hg (THg) in surface sediments varied widely with concentrations from 25 to 264 ng/g. As a whole, Hg pollution in several bays occupied by busy sea traffic and industrial activities, such as Shantou (ST) Bay and Dapeng (DP) Bay were remarkably more serious than others, which reflected the direct effects of anthropogenic activities around the coastal areas. Hg variations in sediment cores clearly display upcore rising trend which obviously correlates with the trend of economic development and urbanization in the last five decades. No significant correlations were found between Hg and organic matter and particle size, suggesting that the distribution of Hg is not fully controlled by these variables.

MyoD and Myf6 gene expression patterns in skeletal muscle during embryonic and posthatch development in the domestic duck (Anas platyrhynchos domestica)

The MyoD and Myf6 genes, which are muscle regulatory factors (MRFs), play major roles in muscle growth and development and initiate muscle fibre formation via the regulation of muscle-specific gene translation. Therefore, MyoD and Myf6 are potential candidate genes for meat production traits in animals and poultry. The objective of this study was to evaluate MyoD and Myf6 gene expression patterns in the skeletal muscle during early developmental stage of ducks. Gene expression levels were detected using the quantitative RT-PCR method in the breast muscle (BM) and leg muscle (LM) at embryonic days 13, 17, 21, 25, 27, as well as at 1 week posthatching in Gaoyou and Jinding ducks (Anas platyrhynchos domestica). The MyoD and Myf6 gene profiles in the two duck breeds were consistent during early development, and MyoD gene expression showed a 'wave' trend in BM and an approximate 'anti-√' trend in LM. Myf6 gene expression in BM showed the highest level at embryonic day 21, which subsequently decreased, although remained relatively high, while levels at embryonic days 13, 17 and 21 were higher in LM. The results of correlation analysis showed that MyoD and Myf6 gene expression levels were more strongly correlated in LM than in BM in both duck breeds. These results indicated that different expression patterns of the MyoD and Myf6 genes in BM and LM may be related to muscle development and differentiation, suggesting that MyoD and Myf6 are integral to skeletal muscle development.

Antibiotics in riverine runoff of the Pearl River Delta and Pearl River Estuary, China: concentrations, mass loading and ecological risks

Ten antibiotics belonging to three groups (macrolides, fluoroquinolones and sulfonamides) were investigated in riverine runoff of the Pearl River Delta (PRD) and Pearl River Estuary (PRE), South China for assessing the importance of riverine runoff in the transportation of contaminants from terrestrial sources to the open ocean. All antibiotics were detected in the eight outlets with concentrations ranging from 0.7 to 127 ng L(-1). The annual mass loadings of antibiotics from the PRD to the PRE and coast were 193 tons with 102 tons from the fluoroquinolone group. It showed that antibiotics decreased from the riverine outlets to the PRE and open ocean. Risk assessment showed that most of these antibiotics showed various ecological risks to the relevant aquatic organisms, in which ofloxacin (OFL), erythromycin (ETM) and ciprofloxacin (CIP) posed high ecological risks to the studied aquatic environments.

Three-dimensional Anderson localization in variable scale disorder

We report on the impact of variable-scale disorder on 3D Anderson localization of a noninteracting ultracold atomic gas. A spin-polarized gas of fermionic atoms is localized by allowing it to expand in an optical speckle potential. Using a sudden quench of the localized density distribution, we verify that the density profile is representative of the underlying single-particle localized states. The geometric mean of the disordering potential correlation lengths is varied by a factor of 4 via adjusting the aperture of the speckle focusing lens. We observe that the root-mean-square size of the localized gas increases approximately linearly with the speckle correlation length, in qualitative agreement with the scaling predicted by weak scattering theory.

Improving the in vivo persistence, distribution and function of cytotoxic T lymphocytes by inhibiting the tumor immunosuppressive microenvironment

Adoptive cell transfer immunotherapy of malignant tumors has the problem of symbiosis between effector cells and tumor cells, a short in vivo residence time, and a poor killing efficiency of effector cells. Thus, releasing effector cells from the cancer immunosuppressive microenvironment and improving their effective time and functional status in vivo would seem to be ideal strategies for facilitating immunotherapy. Low-dose cyclophosphamide administration can effectively break immunotolerance by inhibiting regulatory T cells. In the present study, in order to verify whether the persistence, distribution and function of effector cells can be improved by inhibiting immunosuppressive microenvironment, low-dose cyclophosphamide was previously intraperitoneally injected into melanoma-bearing C57BL/6 mice, thereafter, CFSE-labeled cytotoxic T lymphocytes were transfused intravenously, and their effective time, distributive pattern, and killing efficiency in different groups were observed by measuring the fluorescence intensity and cell cycle of cytotoxic T lymphocytes distributed in various organs, in comparison with tumor growth. We found down-regulating Tregs in vivo can simultaneously reduce the levels of interleukin-10 and transforming growth factor-β. Migration and distribution of cytotoxic T lymphocytes in vivo was found to vary with time. Inhibition of immunotolerance can significantly improve the persistence, distribution, and function of cytotoxic T lymphocytes. Correspondingly, significantly higher secretion of perforin, granzyme B, IL-2, and IFN-γ in tumor tissues with decreased tumor growth was seen in the cyclophosphamide injection group than in the control group. Our study may provide useful information on the cyclophosphamide-mediated mechanism for facilitating tumor immunotherapy by inhibiting the immunosuppressive tumor microenvironment.

Transcriptome network-based method to identify genes associated with unruptured intracranial aneurysms

Intracranial aneurysm is a balloon or sac-like dilatation of blood vessels inside the brain. Despite their importance, the biological mechanisms of intracranial aneurysms are not totally understood. We used public genome-wide gene expression profile data to identify potential genes that are involved in intracranial aneurysm in order to construct a regulation network. Some of the transcription factors and target genes that we identified in this network had been identified as related to intracranial aneurysm in previous studies. We found additional transcription factors and target genes that are apparently related to intracranial aneurysm with this method. The confirmation of previously identified genes and transcription factors supports the usefulness of this transcriptome network analysis for the identification of candidate genes involved in intracranial aneurysm.

Matrine promotes G0/G1 arrest and down-regulates cyclin D1 expression in human rhabdomyosarcoma cells

Matrine has a broad-spectrum of anti-cancer effects and is efficient in the inhibition of proliferation of hepatoma cells, leukemia cells and neuroblastoma cell. However, its efficacy and tentative mechanisms in rhabdomyosarcoma have not been addressed before. This study aimed to investigate the effects of Matrine on cell cycle and expression of cyclin D1 in human rhabdomyosarcoma cells (RD cell line). RD cell line was treated with different concentrations (0, 0.5, 1.0, and 1.5 mg/mL) of Matrine, and cell proliferation and cell cycle were evaluated using, respectively, MTT assay and flow cytometry. The effect of Matrine on cyclin D1 mRNA levels was measured by RT-PCR. There was a dose-dependent inhibition of proliferation in the matrine-treated group (inhibition of proliferation rate in control cells 12.70 ± 0.35%; Matrine-treated cells [0.5, 1.0, and 1.5 mg/mL]: 31.16 ± 0.11%, 42.96 ± 0.9%, and 57.26 ± 0.8%). The G0 / G1 ratio in study groups were, respectively, 58.44 ± 3.57%, 64.79 ± 2.03%, 69.97 ± 2.89% and 75.03 ± 1.23%.Cyclin D1 mRNA levels progressively diminished (control group ratio of cyclin D1 / β-actin: 0.59 ± 0.06; Matrine: 0.35 ± 0.05, 0.27 ± 0.02 and 0.04 ± 0.03). All aforementioned changes were significant (P<0.05). In conclusion, Matrine markedly suppresses cell proliferation in RD cells by decreasing expression of cyclin D1 mRNA and blocking the cell cycle at the G0 / G1 stage.

The incidence of posttransplantation diabetes mellitus during follow-up in kidney transplant recipients and relationship to Fok1 vitamin D receptor polymorphism

BACKGROUND

Posttransplantation diabetes mellitus (PTDM) is a common, serious complication of kidney transplantation. The purpose of this study was to investigate the incidence of and risk factors for PTDM in relationship to Fok1 vitamin D receptor (VDR) polymorphisms.

METHODS

One hundred five kidney transplant recipients with normal glucose values before transplantation were recruited for this study. All patients underwent fasting plasma glucose (FPG) determinations followed by oral glucose tolerance tests (OGTTs) among normal FPG recipients. Every recipient underwent Fok1 VDR polymorphism analysis using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).

RESULTS

Among 105 recipients, 16 (15.24%) developed new-onset PTDM within 6 months after kidney transplantation. Compared with 89 non-PTDM recipients, the mean age was significantly higher among recipients with PTDM: 47.81 ± 15.54 vs 36.62 ± 11.43 years (P = .001). Patients treated with tacrolimus were more susceptible to PTDM (56.25% vs 28.09%; P = .027). The distribution frequencies of Fok1 genotypes in this cohort followed the Hardy-Weinberg equilibrium. The frequencies of 3 genotypes (FF/Ff/ff; P = .040) and 2 alleles (F/f; P = .009) differed between the 2 groups. Multivariate analysis by logistic regression showed age older than 40 years (odds ratio, 7.774; P = .005), VDR Fok1 f allele (odds ratio, 11.765; P = .012), and tacrolimus therapy (odds ratio, 7.499; P = .007) to be related to the development of PTDM.

CONCLUSIONS

The incidence of newly diagnosed PTDM in this study was 15.24%. Fok1 VDR polymorphism was a genetic marker predicting PTDM risk. Age older than 40 years and tacrolimus were independent risk factors for PTDM.

Measurement of J/ψ azimuthal anisotropy in Au+Au collisions at sqrt[s(NN)]=200 GeV

The measurement of J/ψ azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at sqrt[s(NN)]=200 GeV. The measured J/ψ elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/ψ particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

Predicting complicated Crohn's disease and surgery: phenotypes, genetics, serology and psychological characteristics of a population-based cohort

BACKGROUND

Predictors of complicated Crohn's disease (CD), defined as stricturing or penetrating behaviour, and surgery have largely been derived from referral centre populations.

AIM

To investigate whether serological markers, susceptibility genes or psychological characteristics are associated with complicated CD or surgery in a population-based cohort.

METHODS

One hundred and eighty-two members of the Manitoba IBD Cohort with CD phenotyped using the Montreal classification underwent genetic and serological analysis at enrolment and after 5 years. One hundred and twenty-seven had paired sera at baseline and 5 years later and their data were used to predict outcomes at a median of 9.3 years. Serological analysis consisted of a seven antibody panel, and DNA was tested for CD-associated NOD2 variants (rs2066845,rs2076756,rs2066847), ATG16L1 (rs3828309, rs2241880) and IL23R (rs11465804). Psychological characteristics were assessed using semi-structured interviews and validated survey measures.

RESULTS

Sixty-five per cent had complicated CD and 42% underwent surgery. Multivariate analysis indicated that only ASCA IgG-positive serology was predictive of stricturing/penetrating behaviour (OR = 3.01; 95% CI: 1.28-7.09; P = 0.01) and ileal CD (OR = 2.2; 95% CI: 1.07-4.54, P = 0.03). Complicated CD behaviour was strongly associated with surgery (OR = 5.6; 95% CI: 2.43-12.91; P < 0.0001), whereas in multivariate analysis, only ASCA IgG was associated (OR = 2.66; 95% CI, 1.40-5.06, P = 0.003). ASCA titre results were similar at baseline and follow-up. Psychological characteristics were not significantly associated with disease behaviour, serological profile or genotype.

CONCLUSIONS

ASCA IgG at baseline was significantly associated with stricturing/penetrating disease at 9-10 years from diagnosis. Stricturing/penetrating disease was significantly associated with surgery. In a model including serology, the genotypes assessed did not significantly associate with complicated disease or surgery.

Controllable transition of silk fibroin nanostructures: an insight into in vitro silk self-assembly process

Silk fiber is one of the strongest and toughest biological materials with hierarchical structures, where nanofibril with size <20nm is a critical factor in determining its excellent mechanical properties. Although silk nanofibrils have been found in natural and regenerated silk solutions, there is no way to actively control nanofibril formation in aqueous solution. This study shows a simple but effective method of preparing silk nanofibrils by regulating the silk self-assembly process. Through a repeated drying-dissolving process, a silk fibroin solution composed of metastable nanoparticles was first prepared and then used to reassemble nanofibrils with different sizes and secondary conformations under various temperatures and concentrations. These nanofibrils have a similar size to that of natural fibers, providing a suitable unit to further assemble the hierarchical structure in vitro. Several important issues, such as the relationships between silk nanofibrils, secondary conformations and viscosity, are also investigated, giving a new insight into the self-assembly process. In summary, besides rebuilding silk nanofibrils in aqueous solution, this study provides an important model for furthering the understanding of silk structures, properties and forming mechanisms, making it possible to regenerate silk materials with exceptional properties in the future.

Tumor-intrinsic and tumor-extrinsic factors impacting hsp90- targeted therapy

In 1994 the first heat shock protein 90 (Hsp90) inhibitor was identified and Hsp90 was reported to be a target for anticancer therapeutics. In the past 18 years there have been 17 distinct Hsp90 inhibitors entered into clinical trial, and the small molecule Hsp90 inhibitors have been highly valuable as probes of the role of Hsp90 and its client proteins in cancer. Although no Hsp90 inhibitor has achieved regulatory approval, recently there has been significant progress in Hsp90 inhibitor clinical development, and in the past year RECIST responses have been documented in HER2-positive breast cancer and EML4-ALK-positive non-small cell lung cancer. All of the clinical Hsp90 inhibitors studied to date are specific in their target, i.e. they bind exclusively to Hsp90 and two related heat shock proteins. However, Hsp90 inhibitors are markedly pleiotropic, causing degradation of over 200 client proteins and impacting critical multiprotein complexes. Furthermore, it has only recently been appreciated that Hsp90 inhibitors can, paradoxically, cause transient activation of the protein kinase clients they are chaperoning, resulting in initiation of signal transduction and significant physiological events in both tumor and tumor microenvironment. An additional area of recent progress in Hsp90 research is in studies of the posttranslational modifications of Hsp90 itself and Hsp90 co-chaperone proteins. Together, a picture is emerging in which the impact of Hsp90 inhibitors is shaped by the tumor intracellular and extracellular milieu, and in which Hsp90 inhibitors impact tumor and host on a microenvironmental and systems level. Here we review the tumor intrinsic and extrinsic factors that impact the efficacy of small molecules engaging the Hsp90 chaperone machine.

Inhibition of the acquisition of conditioned place aversion by dopaminergic lesions of the central nucleus of the amygdala in morphine-treated rats

The negative affective state of opiate abstinence plays an important role in craving and relapse to compulsive drug use. The dopamine system participates in the reward effects of opiate use and the aversive effect of opiate abstinence. The amygdala is an essential neural substrate for associative learning of emotion. To establish a model of conditioned place aversion (CPA) in morphine-treated rats, we used different visual and tactual cues as conditioned stimuli (CS) within a conditioning apparatus. An injection of naloxone served as the unconditioned stimulus (US). The 6-hydroxydopamine (6-OHDA) lesion technique was used to investigate the effects of the dopaminergic system of the central nucleus of the amygdala (CeA) on naloxone-induced CPA. Rats were rendered physically dependent via administration of increasing doses of morphine delivered via intraperitoneal injection. Doses increased by 20 % each day for 14 days, starting from an initial dose of 6 mg/kg. All rats also received a low dose of naloxone (0.1 mg/kg) by injection 4 hours after morphine treatment on days 11 and 13 to induce CPA in a biased two-compartment conditioned place apparatus. Morphine-dependent rats with sham lesions were found to develop significant CPA after naloxone treatment. Bilateral 6-OHDA lesions of the CeA impaired the acquisition of CPA but had no effect on locomotor activity. These results suggest that the dopaminergic system of the CeA plays an important role in the negative affective state of opiate abstinence.

Arthroscopic reconstruction of the anterior cruciate ligament with the LARS artificial ligament: thirty-six to fifty-two months follow-up study

OBJECTIVES

This study aims to analyze the operating methods and fundamental clinical effects of the reconstruction of the anterior cruciate ligament (ACL) with the Ligament Advancement Reinforcement System (LARS) artificial ligaments using an arthroscopy.

PATIENTS AND METHODS

Fifty-three patients with ACL rupture who were treated using LARS artificial ligaments were enrolled in this retrospective study. The mean age at the time of reconstruction was 31.2 y (range, 22-51y). Average time from injury to surgery was 18 d (range, 5-51 d). Average follow-up period was 45 mo (range 36-52 months). Follow-up examinations included the Lysholm Knee Score and the International Knee Documentation Committee (IKDC) score.

RESULTS

The average Lysholm Knee Score was 53.1±5.8 preoperatively (range, 47-76) versus 93.2±3.4 three years after operation (range, 80-100). Fifty-one of 53 patents (96.2%) showed good or excellent results at final assessment. The final IKDC score 3 years after operation were normal in 28 patients (52.8%), nearly normal in 23 patients (43.4%), and abnormal in 2 patients (3.8%). No postoperative complications, such as infection, ligament rupture, or ligament cinch occurred.

CONCLUSIONS

The results suggest that LARS artificial ligament appears to be an effective graft for ACL reconstruction leading to good knee function and stability. Long-term follow-up should be performed to confirm the durable stability of the knee and the tolerance of the knee to the LARS artificial ligament.

Waist-to-height ratio is the best indicator for undiagnosed type 2 diabetes

AIMS

Early detection of diabetes is important for the prevention of diabetic complications. The best adiposity index for indicating Type 2 diabetes mellitus remains unclear. We aimed to identify the optimal adiposity measure among BMI, waist circumference, waist-hip ratio and waist-to-height ratio to indicate undiagnosed Type 2 diabetes and impaired fasting glucose in Chinese adults.

METHODS

A total of 7567 participants aged 20-79 years were included in this study. Impaired fasting glucose was defined as a fasting plasma glucose level of 6.1-6.9 mmol/l in participants without diabetes. Undiagnosed Type 2 diabetes was identified as fasting plasma glucose ≥ 7.0 mmol/l when neither a history of diabetes nor use of hypoglycaemic drugs was present. Body weight, height, waist and hip circumferences were measured following standard procedures. Data were analysed using logistic regression and areas under the receiver operating characteristic curves.

RESULTS

Of the 7567 participants, 536 were defined as having impaired fasting glucose and 690 were patients with Type 2 diabetes, including 290 (3.8%) persons with undiagnosed diabetes. In multivariate logistic regression, the odds ratios of waist-to-height ratio (≥ 0.5) were stronger than BMI (≥ 24 kg/m²), waist circumference (≥ 85 cm in men and ≥ 80 cm in women) and waist-hip ratio (≥ 0.85) for undiagnosed Type 2 diabetes and impaired fasting glucose. Among the four indices, waist-to-height ratio ≥ 0.5 showed the largest area under the receiver operating characteristic curve for diagnosing undiagnosed Type 2 diabetes (0.725, 95% CI 0.693-0.756) and impaired fasting glucose (0.662, 95% CI 0.638-0.687).

CONCLUSIONS

By comparison with BMI, waist circumference and waist-hip ratio, waist-to-height ratio ≥ 0.5 may be the best indicator for undiagnosed Type 2 diabetes and impaired fasting glucose.