Association between prolonged breastfeeding and bone mineral density and osteoporosis in postmenopausal women: KNHANES 2010-2011

This study showed that a negative correlation between duration of breastfeeding and bone mineral density (BMD) in the lumbar spine and prolonged breastfeeding is an independent risk for osteoporosis in postmenopausal women. The present study suggests that postmenopausal women with a history of prolonged breastfeeding require more careful screening for osteoporosis.

INTRODUCTION

Several studies suggest that breastfeeding and childbirth lead to maternal calcium loss and a decline in BMD. While the association between breastfeeding and BMD immediately after weaning is well-established, the effects of breastfeeding on postmenopausal women have been controversial. The aim of this study was to examine the effects of breastfeeding on bone mineral density (BMD) and the prevalence of osteoporosis in postmenopausal women.

METHODS

The present study was a cross-sectional survey based on the Korea National Health and Nutrition Examination Survey (KNHANES) 2010 and 2011 data. The association between breastfeeding and BMD and osteoporosis was examined in 1222 postmenopausal women.

RESULTS

The duration of breastfeeding and BMD in the lumbar spine showed a negative correlation. The association between duration of breastfeeding and BMD remained significant after adjustment for reproductive factors and other confounding factors (P = 0.008). However, the number of deliveries and age at the time of delivery did not correlate with BMD at any site after adjustment. Moreover, the prevalence of osteoporosis in postmenopausal women with a history of prolonged breastfeeding was significantly higher than that in women with a short history of breastfeeding (≥37 months, OR = 3.292; 95 % CI 1.485-7.299). The prevalence of lumbar spine fracture showed a significant increasing trend with the increase in the duration of breastfeeding.

CONCLUSION

Prolonged breastfeeding was significantly associated with low BMD in the lumbar spine and higher prevalence of osteoporosis. However, the number of deliveries or age at the time of childbirth did not influence BMD.

Prognostic value of tumor-infiltrating lymphocytes in Epstein-Barr virus-associated gastric cancer

BACKGROUND

This study explored the prognostic impact of tumor-infiltrating lymphocytes (TILs) and investigated whether three histologic subtypes (lymphoepithelioma-like carcinoma, carcinoma with Crohn's disease-like lymphoid reaction, and conventional-type adenocarcinoma) could stratify a prognostic subset for patients with Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC).

MATERIALS AND METHODS

After reviewing 1318 consecutive cases of surgically resected or endoscopic submucosal dissected gastric cancers, 120 patients were identified as EBV-positive using EBV-encoded RNA in situ hybridization. The evaluation of the percentage of intratumoral (iTu-) and stromal (str-) TILs was carried out, and the cases were also subclassified into three histologic subtypes as noted above.

RESULTS

Among the 120 patients, 73 patients (60.8%) and 60 patients (50.0%) were determined as str-TIL-positive and iTu-TIL-positive, respectively. In a univariate analysis, str-TIL-positivity was significantly associated with longer recurrence-free survival (RFS; P = 0.002) and disease-free survival (DFS; P = 0.008), yet not overall survival (OS; P = 0.145). While iTu-TIL-positivity has a tendency of favorable outcome indicator for DFS and OS, but statistically significant differences were not shown, respectively (RFS, P = 0.058; DFS, P = 0.151; OS, P = 0.191). In a multivariate analysis using a Cox proportional hazard model adjusted for age, pTNM stage, lymphatic invasion, perineural invasion, and venous invasion; histologic subtype, WHO classification, and str-TIL-positivity were independently or tentatively associated with favorable RFS (hazard ratio [HR] = 12.193, 95% confidence interval [95% CI] 1.039-143.055, P = 0.047) or DFS (HR = 4.836, 95% CI 0.917-25.525, P = 0.063).

CONCLUSION

The histologic subclassification and TILs can be used to predict RFS and DFS for patients with EBVaGC.

Polymorphisms in period genes and bone response to hormone therapy in postmenopausal Korean women

OBJECTIVE

In this study, we aimed to explore the association between polymorphisms in the period (PER) gene and bone response to hormone therapy (HT) in postmenopausal Korean women.

METHODS

The PER1 c.2284C > G, c.2247C > T, PER2 c.3731G > A, PER3 c.2592G > A, c.3083T > C polymorphisms, and PER3 54bp variable number of tandem repeats (VNTR) were analyzed in 509 postmenopausal Korean women who received HT. Bone mineral density (BMD) at the lumbar spine and femoral neck before and after 1 year of HT and serum levels of osteoprotegerin (OPG), soluble receptor activator of the nuclear factor-κB ligand (sRANKL) and bone turnover markers were measured after 6 months of HT.

RESULTS

The PER1 c.2884 C > G polymorphism and PER3 54bp VNTR were associated with annual percent changes in BMD of the femoral neck after 1 year of HT (p < 0.05). Changes in BMD at the femoral neck in the non-CC genotype of the PER1 c.2884C > G polymorphism and in the 4-repeat homozygote of PER3 54bp VNTR were significantly lower than those in CC genotype and non-4-repeat homozygote, respectively. The PER1 c.2884C > G polymorphism was associated with the non-response (>3% BMD loss/year after HT) of HT. The non-CC genotype of the PER1 c.2884C > G polymorphism showed a 1.92-times higher risk of non-response at the lumbar spine and/or femoral neck (p = 0.01) compared with the CC genotype. No significant changes in bone markers after 6 months of HT were noted according to the PER1 c.2884C > G polymorphism.

CONCLUSIONS

The PER1 c.2884C > G polymorphism may be associated with risk of non-response to HT in postmenopausal Korean women.

Association of urinary sodium/creatinine ratio with bone mineral density in postmenopausal women: KNHANES 2008-2011

Accumulating evidence shows that high sodium chloride intake increases urinary calcium excretion and may be a risk factor for osteoporosis. However, the effect of oral sodium chloride intake on bone mineral density (BMD) and risk of osteoporosis has been inadequately researched. The aim of the present study was to determine whether urinary sodium excretion (reflecting oral sodium chloride intake) associates with BMD and prevalence of osteoporosis in postmenopausal women. This cross-sectional study involved a nationally representative sample consisting of 2,779 postmenopausal women who participated in the Korea National Health and Nutritional Examination Surveys in 2008-2011. The association of urinary sodium/creatinine ratio with BMD and other osteoporosis risk factors was assessed. In addition, the prevalence of osteoporosis was assessed in four groups with different urinary sodium/creatinine ratios. Participants with osteoporosis had significantly higher urinary sodium/creatinine ratios than the participants without osteoporosis. After adjusting for multiple confounding factors, urinary sodium/creatinine ratio correlated inversely with lumbar spine BMD (P = 0.001). Similarly, when participants were divided into quartile groups according to urinary sodium/creatinine ratio, the average BMD dropped as the urinary sodium/creatinine ratio increased. Multiple logistic regression analysis revealed that compared to quartile 1, quartile 4 had a significantly increased prevalence of lumbar spine osteoporosis (odds ratios 1.346, P for trend = 0.044). High urinary sodium excretion was significantly associated with low BMD and high prevalence of osteoporosis in lumbar spine. These results suggest that high sodium chloride intake decreases lumbar spine BMD and increases the risk of osteoporosis in postmenopausal women.

Comparison of streamlined liner of the pharynx airway (SLIPA ™) and laryngeal mask airway: a systematic review and meta-analysis

We performed a systematic review to compare the efficacy and safety of the streamlined liner of the pharynx airway and laryngeal mask airway used in adults during general anaesthesia. We included 14 studies with studies with 1273 patients in total. There was no evidence of a difference between the two devices in insertion success rate on the first attempt (13 studies, 1143 patients), insertion time (seven studies, 576 patients), ease of insertion (five studies, 466 patients), oropharyngeal leak pressure (eight studies, 771 patients) and the quality of the fibreoptic view of the larynx through the device (three studies, 281 patients). The relative risk (95% CI) of bloodstaining of the device (nine studies, 859 patients) was 2.09 (1.46-3.00) for the streamlined liner of the pharynx airway compared with the laryngeal mask airway. Other adverse events were comparable. Subgroup analysis suggested that the insertion by novice users might be faster and more successful with the streamlined liner of the pharynx airway than the laryngeal mask airway; however, this was from only two studies and 186 patients. The method of size selection of the streamlined liner of the pharynx airway device might also affect the speed of insertion: choosing according to the width of the patient's thyroid cartilage, rather than height, may produce better results.

The influence of surgical factors on dislocation of the meniscal bearing after Oxford medial unicompartmental knee replacement: a case-control study

The aim of this study was to evaluate the risk factors for dislocation of the bearing after a mobile-bearing Oxford medial unicompartmental knee replacement (UKR) and to test the hypothesis that surgical factors, as measured from post-operative radiographs, are associated with its dislocation From a total of 480 UKRs performed between 2001 and 2012, in 391 patients with a mean age of 66.5 years (45 to 82) (316 female, 75 male), we identified 17 UKRs where bearing dislocation occurred. The post-operative radiological measurements of the 17 UKRs and 51 matched controls were analysed using conditional logistic regression analysis. The post-operative radiological measurements included post-operative change in limb alignment, the position of the femoral and tibial components, the resection depth of the proximal tibia, and the femoral component-posterior condyle classification. We concluded that a post-operative decrease in the posterior tibial slope relative to the pre-operative value was the only significant determinant of dislocation of the bearing after medial Oxford UKR (odds ratio 1.881; 95% confidence interval 1.272 to 2.779). A post-operative posterior tibial slope < 8.45° and a difference between the pre-operative and post-operative posterior tibial slope of > 2.19° may increase the risk of dislocation.

Clusterin/apolipoprotein J attenuates angiotensin II-induced renal fibrosis

The blockade of angiotensin II (Ang II) is a major therapeutic strategy for diabetic nephropathy. The main roles of Ang II in renal disease are mediated via the Ang type 1 receptor (AT1R). Upregulation of clusterin/apolipoprotein J has been reported in nephropathy models, suggesting it has a protective role in nephropathogenesis. Here, we studied how clusterin acts against Ang II-induced renal fibrosis. Levels of AT1R and fibrotic markers in clusterin-/- mice and Ang II infused rats transfected with an adenovirus encoding clusterin were evaluated by immunoblot analysis, real time RT-PCR, and immunohistochemical staining. The effect of clusterin on renal fibrosis was evaluated in NRK-52E cells, a cultured renal tubular epithelial cell line, using immunoblot analysis and real time RT-PCR. Nuclear localization of NF-κB was evaluated using immunofluorecence and co-immunoprecipitation. Renal fibrosis and expression of AT1R was higher in the kidneys of clusterin^-/- mice than in those of wild-type mice. Furthermore, loss of clusterin accelerated Ang II-stimulated renal fibrosis and AT1R expression. Overexpression of clusterin in proximal tubular epithelial cells decreased the levels of Ang II-stimulated fibrotic markers and AT1R. Moreover, intrarenal delivery of clusterin attenuated Ang II-mediated expression of fibrotic markers and AT1R in rats. Fluorescence microscopy and co-immunoprecipitation in conjunction with western blot revealed that clusterin inhibited Ang II-stimulated nuclear localization of p-NF-κB via a direct physical interaction and subsequently decreased the AT1R level in proximal tubular epithelial cells. These data suggest that clusterin attenuates Ang II-induced renal fibrosis by inhibition of NF-κB activation and subsequent downregulation of AT1R. This study raises the possibility that clusterin could be used as a therapeutic target for Ang II-induced renal diseases.

Orphan nuclear receptor Nur77 mediates fasting-induced hepatic fibroblast growth factor 21 expression

The fasting-induced hepatic hormone, fibroblast growth factor 21 (FGF21), is a potential candidate for the treatment of metabolic syndromes. Although peroxisome proliferator-activated receptor (PPAR)α is known to play a major role in the induction of hepatic FGF21 expression, other fasting-induced transcription factors that induce FGF21 expression have not yet been fully studied. In the present study, we investigated whether the fasting-induced activation of the orphan nuclear receptor Nur77 increases hepatic FGF21 expression. We found that fasting induced hepatic Nur77 and FGF21 expression. Glucagon and forskolin increased Nur77 and FGF21 expression in vivo and in vitro, respectively, and adenovirus-mediated overexpression of Nur77 (Ad-Nur77) increased FGF21 expression in vitro and in vivo. Moreover, knockdown of endogenous Nur77 expression by siRNA-Nur77 abolished the effect of forskolin on FGF21 expression. The results of ChIP assays, EMSA, and mutagenesis analysis showed that Nur77 bound to the putative NBRE of the FGF21 promoter in cultured hepatocytes and fasting induced Nur77 binding to the FGF21 promoter in vivo. Knockdown of PPARα partially inhibited forskolin-induced FGF21 expression, suggesting PPARα involvement in glucagon-stimulated FGF21 expression. In addition, double knockdown of PPARα and Nur77 further diminished FGF21 expression in cultured hepatocytes. In conclusion, this study shows that Nur77 mediates fasting-induced hepatic FGF21 expression, and suggests an alternative mechanism via which hepatic FGF21 transcription is mediated under fasting conditions.

Sitagliptin attenuates methionine/choline-deficient diet-induced steatohepatitis

AIMS

Accumulating evidence suggests that inhibitors of dipeptidyl peptidase-4 (DPP-4), such as sitagliptin, may play an important role in the prevention of non-alcoholic steatohepatitis (NASH). This study was conducted to elucidate whether sitagliptin could prevent steatohepatitis by inhibiting pathways involved in hepatic steatosis, inflammation, and fibrosis.

METHODS

C57BL/6 mice were fed a methionine/choline-deficient (MCD) diet with or without supplement with sitagliptin for 5 weeks. Liver and adipose tissue from mice were examined histologically and immunohistochemically to estimate the effect of sitagliptin on the development of NASH.

RESULTS

Supplementation with sitagliptin resulted in significant improvement of MCD diet-induced fat accumulation in the liver. In addition, sitagliptin treatment lowered fatty acid uptake, expression of VLDL receptor and hepatic triglyceride content. Sitagliptin also effectively attenuated MCD diet-induced hepatic inflammation, endoplasmic reticulum (ER) stress, and liver injury, as evidenced by reduced proinflammatory cytokine levels, ER stress markers, and TUNEL staining. Expression of CYP2E1 and 4NHE were strongly increased by the MCD diet, but this effect was successfully prevented by sitagliptin treatment. Furthermore, sitagliptin significantly decreased levels of MCD diet-induced fibrosis-associated proteins such as fibronectin and α-SMA in the liver. Inflammatory and atrophic changes of adipose tissue by MCD diet were restored by sitagliptin treatment.

CONCLUSIONS

Sitagliptin attenuated MCD diet-induced hepatic steatosis, inflammation, and fibrosis in mice through amelioration of mechanisms responsible for the development of NASH, including CD36 expression, NF-κB activation, ER stress, CYP2E1 expression, and lipid peroxidation. Treatment with sitagliptin may represent an effective approach for the prevention and treatment of NASH.

Association between polymorphisms in period genes and bone density in postmenopausal Korean women

OBJECTIVE

In the present study, we aimed to investigate the association between genetic polymorphisms in period (PER) genes and bone mineral density (BMD) in postmenopausal Korean women.

METHODS

The PER1 c.2247C> T and c.2884C> G polymorphisms; the PER2 c.661G> A and c.3731G> A polymorphisms; the PER3 c.2592G> A, c.3029C> T, c.3035C> T, and c.3083T> C polymorphisms, and the 54 bp variable number tandem repeats polymorphism were analyzed in 551 postmenopausal Korean women. Serum leptin, soluble leptin receptor, osteoprotegerin, soluble receptor activator of the nuclear factor-κB ligand, and bone markers including bone alkaline phosphatase and carboxy-terminal telopeptide of type I collagen were measured, and the lumbar spine and femoral neck BMDs were also determined.

RESULTS

The PER2 c.661G> A, PER3 c.3029C> T and c.3035C> T polymorphisms were not observed. The PER2 and PER3 polymorphisms evaluated were not related to BMD, whereas associations of the c.2247C> T and c.2884C> G polymorphisms in PER1 with the lumbar spine BMD were observed both singly and in combination. The CC haplotype homozygotes showed significantly lower lumbar spine BMD than participants with other genotypes. Additionally, 2.01-fold higher odds for osteoporosis of the lumbar spine were found in the CC haplotype homozygotes compared to women not carrying the haplotype CC allele. No significant differences in bone markers were detected according to the PER1 haplotype genotype.

CONCLUSIONS

Our results suggest that both the PER1 c.2247C> T and c.2884C> G polymorphisms may be genetic factors affecting the lumbar spine BMD in postmenopausal Korean women.

Transcriptional regulation of fibroblast growth factor 21 expression

Fibroblast growth factor 21 (FGF21) is an attractive target for treating metabolic disease due to its wide-ranging beneficial effects on glucose and lipid metabolism. Circulating FGF21 levels are increased in insulin-resistant states; however, endogenous FGF21 fails to improve glucose and lipid metabolism in obesity, suggesting that metabolic syndrome is an FGF21-resistant state. Therefore, transcription factors for FGF21 are potential drug targets that could increase FGF21 expression in obesity and reduce FGF21 resistance. Despite many studies on the metabolic effects of FGF21, the transcriptional regulation of FGF21 gene expression remains controversial and is not fully understood. As the FGF21 transcription factor pathway is one of the most promising targets for the treatment of metabolic syndrome, further investigation of FGF21 transcriptional regulation is required.

Trend analysis of diabetic prevalence and incidence in a rural area of South Korea between 2003-2008

Aims/Introduction:  This study determined the change in prevalence of diabetes and prediabetes over a period of 5 years in South Korea. The incidence of diabetes and prediabetes and risk factors associated with the development of diabetes were also investigated.

Materials and Methods:  The Dalseong population‐based cohort survey recruited 1806 subjects who were over 20‐years‐old in 2003. Five years later, 1287 of the original subjects were re‐evaluated and 187 new subjects were added to the study. All participants completed a questionnaire, were given a physical examination, and provided blood samples for analysis including 2 h oral glucose tolerances.

Results:  Age‐adjusted prevalence of diabetes rose from 6.7% in 2003 to 9.1% in 2008. The prevalence of prediabetes also increased from 18.5% in 2003 to 28.4% in 2008. The incidence rates of diabetes and prediabetes were 18.3 per 1000 person‐years and 55.4 per 1000 person‐years, respectively. The development of diabetes was associated with impaired fasting glucose (IFG) (odds ratio [OR] 5.661), impaired glucose tolerance (IGT) (OR: 6.013), age (OR 1.013), and waist‐to‐hip ratio (OR 1.513). After excluding the IFG and IGT, systolic blood pressure (OR 1.023), high‐sensitivity C‐reactive protein (hsCRP; OR 1.097), triglyceride (OR 1.002) and waist‐to‐hip ratio (OR 1.696) were statistically significant risk factors in a multivariate logistic regression analysis.

Conclusions:  A significant rise in the prevalence of diabetes and prediabetes was observed between 2003 and 2008. In addition, this study newly demonstrated that waist‐to‐hip ratio and hsCRP were associated with the development of diabetes after adjusting for several confounding factors. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00045.x, 2010)

Spin-induced band modifications of graphene through intercalation of magnetic iron atoms

Intercalation of magnetic iron atoms through graphene formed on the SiC(0001) surface is found to induce significant changes in the electronic properties of graphene due mainly to the Fe-induced asymmetries in charge as well as spin distribution. From our synchrotron-based photoelectron spectroscopy data together with ab initio calculations, we observe that the Fe-induced charge asymmetry results in the formation of a quasi-free-standing bilayer graphene while the spin asymmetry drives multiple spin-split bands. We find that Fe adatoms are best intercalated upon annealing at 600 °C, exhibiting split linear π-bands, characteristic of a bilayer graphene, but much diffused. Subsequent changes in the C 1s, Si 2p, and Fe 3p core levels are consistently described in terms of Fe-intercalation. Our calculations together with a spin-dependent tight binding model ascribe the diffuse nature of the π-bands to the multiple spin-split bands originated from the spin-injected carbon atoms residing only in the lower graphene layer.

Serum irisin levels in new-onset type 2 diabetes

AIMS

Irisin has been identified as a novel myokine that drives brown-fat-like conversion of white adipose tissue. In this cross-sectional study, we investigated whether serum irisin levels are decreased in patients with type 2 diabetes (T2D) compared with control subjects with normal glucose tolerance (NGT), and assessed the association between serum irisin levels and various metabolic parameters.

METHODS

The study population was selected from a population-based study and included 104 subjects with NGT and 104 subjects with new-onset T2D. Serum irisin and adiponectin levels and metabolic parameters were measured. Multivariate logistic regression analysis was performed to assess the association between irisin levels and newly diagnosed T2D.

RESULTS

Serum irisin levels were significantly decreased in the new-onset T2D group compared with the NGT control group (p=0.003). In a multivariable model adjusted for various metabolic parameters, increased irisin levels were associated with reduced odds (OR 0.64, 95% CI 0.47-0.88, p=0.006) of prevalent newly diagnosed T2D. Furthermore, multiple regression analysis showed that 2 h plasma glucose was an independent variable influencing serum irisin levels (p=0.004).

CONCLUSION

In the present study, we found that serum irisin levels were decreased in T2D patients and inversely associated with newly diagnosed T2D, suggesting that irisin may play a crucial role in glucose intolerance and T2D.

Association of 11β-hydroxysteroid dehydrogenase type 1 gene polymorphisms with serum alanine aminotransferase activity

AIMS

11β-Hydroxysteroid dehydrogenase type 1 (HSD11B1), which converts inactive glucocorticoid to active glucocorticoid, plays a critical role in pathogenesis of non-alcoholic fatty liver disease (NAFLD). Serum alanine aminotransferase (ALT), an indicator of hepatocellular injury, has been suggested as a surrogate marker for NAFLD. To date, no study has specifically examined the relationship between HSD11B1 gene polymorphisms and ALT.

METHODS

A study was conducted to examine the association of common single nucleotide polymorphisms (SNPs) in HSD11B1 (rs12086634, rs1000283) with serum ALT level in 756 Korean subjects (348 males and 408 females). ALT values were divided into two groups: elevated (>33U/l in males, >25U/l in females) and normal.

RESULTS

SNPs showed a significant association with elevated ALT. According to results of logistic regression analysis adjusted for confounding variables, the GT+GG genotype for rs12086634 and the GA+AA genotype for rs1000283 showed significantly higher frequencies of elevated ALT, compared with the TT and GG genotypes, respectively (GT/GG vs. TT; OR 1.685, 95% CI 1.175-2.416, P=0.005, GA/AA vs. GG; OR 2.057, 95% CI 1.401-3.020, P<0.001, respectively).

CONCLUSIONS

HSD11B1 polymorphisms (rs12086634 and rs1000283) are associated with elevated levels of ALT. Findings from this study suggest a possible association between HSD11B1 polymorphisms and hepatocellular injury, such as that seen in patients with NAFLD.

An on-time power-aware scheduling scheme for medical sensor SoC-based WBAN systems

The focus of many leading technologies in the field of medical sensor systems is on low power consumption and robust data transmission. For example, the implantable cardioverter-defibrillator (ICD), which is used to maintain the heart in a healthy state, requires a reliable wireless communication scheme with an extremely low duty-cycle, high bit rate, and energy-efficient media access protocols. Because such devices must be sustained for over 5 years without access to battery replacement, they must be designed to have extremely low power consumption in sleep mode. Here, an on-time, energy-efficient scheduling scheme is proposed that performs power adjustments to minimize the sleep-mode current. The novelty of this scheduler is that it increases the determinacy of power adjustment and the predictability of scheduling by employing non-pre-emptible dual priority scheduling. This predictable scheduling also guarantees the punctuality of important periodic tasks based on their serialization, by using their worst case execution time) and the power consumption optimization. The scheduler was embedded into a system on chip (SoC) developed to support the wireless body area network—a wakeup-radio and wakeup-timer for implantable medical devices. This scheduling system is validated by the experimental results of its performance when used with life-time extensions of ICD devices.

Association of the DDAH2 gene polymorphism with type 2 diabetes and hypertension

AIMS

The aim of this study was to investigate whether the polymorphism of DDAH2 is associated with type 2 diabetes and hypertension in Korean population.

METHODS

Total 605 subjects were included in this study: 403 patients with type 2 diabetes and 202 non-diabetic control subjects. The SNP rs805304 and rs2272592 in DDAH2 were analyzed. We examined the association of SNP rs805304 and rs2272592 in DDAH2 with type 2 diabetes and hypertension.

RESULTS

SNP rs2272592 was significantly associated with type 2 diabetes (P<0.001) while SNP rs805304 was not (P=0.716). We observed that the prevalence of the AG+GG genotypes were significantly greater than AA homozygotes in type 2 diabetes (AA vs AG+GG; OR 20.74, 95% CI 6.48-66.35, P<0.001). Significance was maintained after adjusting for age, sex, BMI, DBP and BUN (OR 21.03, 95% CI 2.83-151.14, P=0.003). Both SNP rs805304 and rs2272592 in DDAH2 were not significantly associated with hypertension.

CONCLUSIONS

In the present study, we found that SNP rs2272592 in DDAH2 is associated with type 2 diabetes but SNP rs805304 in DDAH2 is not. DDAH2 SNP rs2272592 AG+GG genotypes are associated with genetic susceptibility to type 2 diabetes in Korean population.

Association of pyruvate dehydrogenase kinase 4 gene polymorphisms with type 2 diabetes and metabolic syndrome

AIMS

Pyruvate dehydrogenase kinase 4 (PDK4) plays a crucial role in glucose utilization and lipid metabolism by regulating the pyruvate dehydrogenase complex (PDC) and is an emerging therapeutic target for type 2 diabetes. To date, no study has specifically examined the relationship between PDK4 gene polymorphisms and type 2 diabetes or metabolic syndrome.

METHODS

The association of common single nucleotide polymorphisms (SNPs) was examined in PDK4 [-208A/G (rs10085637), IVS3+192C/T (rs3779478), IVS6+31A/G (rs2301630), IVS7+514A/G (rs12668651), IVS10+75C/T (rs10247649)] with type 2 diabetes and metabolic syndrome in 651 Korean subjects with type 2 diabetes and 350 nondiabetic Korean subjects. The association of these SNPs with clinical parameters related to metabolic syndromes including obesity, hyperglycemia, hypertension, and dyslipidemia was also examined.

RESULTS

No significant association was found between the studied SNPs and type 2 diabetes, metabolic syndrome, or clinical parameters. The PDK4 gene haplotype ACAGC showed a modest association with type 2 diabetes. However, the significance of this association was lost after considering for multiple comparisons.

CONCLUSIONS

PDK4 polymorphisms may not be associated with type 2 diabetes or metabolic syndrome. Further studies utilizing a larger study population are required to confirm these results.

Clusterin attenuates the development of renal fibrosis

Upregulation of clusterin occurs in several renal diseases and models of nephrotoxicity, but whether this promotes injury or is a protective reaction to injury is unknown. Here, in the mouse unilateral ureteral obstruction model, obstruction markedly increased the expression of clusterin, plasminogen activator inhibitor-1 (PAI-1), type I collagen, and fibronectin. Compared with wild-type mice, clusterin-deficient mice exhibited higher levels of PAI-1, type I collagen, and fibronectin and accelerated renal fibrosis in response to obstruction. In cultured rat tubular epithelium-like cells, adenovirus-mediated overexpression of clusterin inhibited the expression of TGF-β-stimulated PAI-1, type I collagen, and fibronectin. Clusterin inhibited TGF-β-stimulated Smad3 activity via inhibition of Smad3 phosphorylation and its nuclear translocation. Moreover, intrarenal delivery of adenovirus-expressing clusterin upregulated expression of clusterin in tubular epithelium-like cells and attenuated obstruction-induced renal fibrosis. In conclusion, clusterin attenuates renal fibrosis in obstructive nephropathy. These results suggest that upregulation of clusterin during renal injury is a protective response against the development of renal fibrosis.

Alpha-lipoic acid attenuates methionine choline deficient diet-induced steatohepatitis in C57BL/6 mice

AIMS

Non-alcoholic steatohepatitis (NASH) is a liver disease that causes fat accumulation, inflammation and fibrosis. Increased oxidative stress contributes to hepatic inflammation and fibrosis by upregulation of Cytochrome P450 2E1 (CYP2E1), endoplasmic reticulum (ER) stress and mitogen-activated protein kinase (MAPK) activity. This study examined whether alpha-lipoic acid (ALA), a naturally occurring thiol antioxidant, prevents steatohepatitis through the inhibition of several pathways involved in hepatic inflammation and fibrosis.

MAIN METHODS

C57BL/6 mice were fed an MCD diet with or without ALA for 4weeks. Liver sections from mice on control or MCD diets with or without ALA were stained with hematoxylin-eosin, oil red O, and anti-4-HNE antibody. The effects of ALA on methionine-choline deficient MCD-diet induced plasma AST and ALT as well as tissue TBARS were measured. The effects of ALA on CYP2E1 expression, ER stress, MAPK levels, and NF-κB activity in MCD diet-fed mice liver were measured by northern and western blot analysis.

KEY FINDINGS

Dietary supplementation with ALA reduced MCD diet-induced hepatic lipid accumulation, hepatic inflammation, TBARS, 4-HNE, and plasma ALT and AST levels. These effects were associated with a reduced expression of CYP2E1 and reduced ER stress and MAPK and NF-κB activity.

SIGNIFICANCE

Taken together, the results of the present study indicate that ALA attenuates steatohepatitis through inhibition of several pathways, and provide the possibility that ALA can be used to prevent the development and progression of non-alcoholic fatty liver disease in patients who have strong risk factors for NASH.

Serum thyrotropin as a risk factor for thyroid malignancy in euthyroid subjects with thyroid micronodule

BACKGROUND

An elevated thyroid stimulating hormone (TSH) level is a risk factor for differentiated thyroid cancer. The present study investigated whether TSH is a risk factor for thyroid microcarcinoma (TMC) in euthyroid subjects with a micronodule.

METHODS

In this cross-sectional study, 483 euthyroid subjects (77 males patients, 406 females patients) with a thyroid micronodule were enrolled and underwent ultrasound guided fine-needle aspiration biopsy. Serum TSH level was measured in every subject. The final diagnostic outcome (malignant or benign) was defined in conjunction with cytology and histology.

RESULTS

Compared with the patients below the population mean, patients above the population mean had a significantly higher malignancy rate (10.8% vs 4.8%, p = .025). Multiple logistic regression analysis revealed TSH as an independent risk factor for malignancy in euthyroid patients with a micronodule (odds ratio, 1.449; 95% confidence interval, 1.033-2.033; p = .031).

CONCLUSIONS

Measurement of TSH in subjects with a thyroid micronodule is helpful to estimate cancer risk.