Reduced Fine-Tuning in Supersymmetry with R-parity violation

Both electroweak precision measurements and simple supersymmetric extensions of the standard model prefer a mass of the Higgs boson less than the experimental lower limit of 114 GeV. We show that supersymmetric models with R parity violation and baryon number violation have a significant range of parameter space in which the Higgs dominantly decays to six jets. These decays are much more weakly constrained by current LEP analyses and would allow for a Higgs mass near that of the $Z$. In general, lighter scalar quark and other superpartner masses are allowed and the fine-tuning typically required to generate the measured scale of electroweak symmetry breaking is ameliorated. The Higgs would potentially be discovered at hadron colliders via the appearance of new displaced vertices. The lightest neutralino could be discovered by a scan of vertex-less events LEP I data.Comment: 5 pages, 2 figures. Significant detail added to the arguments regarding LEP limits - made more quantitative. Better figures used, plotting more physical quantities. Typos corrected and references updated. Conclusions unchange

Elevated fasting insulin predicts the future incidence of metabolic syndrome: a 5-year follow-up study

<p>Abstract</p> <p>Background</p> <p>There is controversy about the specific pathophysiology of metabolic syndrome (MS) but several authors have argued that hyperinsulinemia is a key feature of the cluster. We aimed to assess whether the baseline insulin levels could predict the development of MS in a well characterised cohort of otherwise healthy adults who were followed over a five year period.</p> <p>Methods</p> <p>We identified 2, 350 Koreans subjects who did not have MS in 2003 and who were followed up in 2008. The subjects were divided into 4 groups according to the baseline quartiles of fasting insulin, and the predictors of the incidence of MS were analyzed using multivariate regression analysis.</p> <p>Results</p> <p>Over the follow up period, 8.5% of the cohort developed MS. However, 16.4% of the subjects in the highest quartile of the insulin levels developed MS. In a model that included gender, age, the smoking status, the exercise level, alcohol consumption and the systolic blood pressure, the subjects in the highest quartile of the insulin levels had more than a 5 times greater risk of developing MS compared that of the subjects in the lowest quartile. This predictive importance remained significant even after correcting for all the individual features of MS.</p> <p>Conclusions</p> <p>These data suggest that high baseline fasting insulin levels are independent determinants for the future development of MS.</p

Deficiency of Retinaldehyde Dehydrogenase 1 Induces BMP2 and Increases Bone Mass In Vivo

The effects of retinoids, the structural derivatives of vitamin A (retinol), on post-natal peak bone density acquisition and skeletal remodeling are complex and compartment specific. Emerging data indicates that retinoids, such as all trans retinoic acid (ATRA) and its precursor all trans retinaldehyde (Rald), exhibit distinct and divergent transcriptional effects in metabolism. Despite these observations, the role of enzymes that control retinoid metabolism in bone remains undefined. In this study, we examined the skeletal phenotype of mice deficient in retinaldehyde dehydrogenase 1 (Aldh1a1), the enzyme responsible for converting Rald to ATRA in adult animals. Bone densitometry and micro-computed tomography (µCT) demonstrated that Aldh1a1-deficient (Aldh1a1−/−) female mice had higher trabecular and cortical bone mass compared to age and sex-matched control C57Bl/6 wild type (WT) mice at multiple time points. Histomorphometry confirmed increased cortical bone thickness and demonstrated significantly higher bone marrow adiposity in Aldh1a1−/− mice. In serum assays, Aldh1a1−/− mice also had higher serum IGF-1 levels. In vitro, primary Aldh1a1−/− mesenchymal stem cells (MSCs) expressed significantly higher levels of bone morphogenetic protein 2 (BMP2) and demonstrated enhanced osteoblastogenesis and adipogenesis versus WT MSCs. BMP2 was also expressed at higher levels in the femurs and tibias of Aldh1a1−/− mice with accompanying induction of BMP2-regulated responses, including expression of Runx2 and alkaline phosphatase, and Smad phosphorylation. In vitro, Rald, which accumulates in Aldh1a1−/− mice, potently induced BMP2 in WT MSCs in a retinoic acid receptor (RAR)-dependent manner, suggesting that Rald is involved in the BMP2 increases seen in Aldh1a1 deficiency in vivo. Collectively, these data implicate Aldh1a1 as a novel determinant of cortical bone density and marrow adiposity in the skeleton in vivo through modulation of BMP signaling

Triglyceride glucose index predicts coronary artery calcification better than other indices of insulin resistance in Korean adults: the Kangbuk Samsung Health Study

Purpose Insulin resistance is one of the most important mechanisms in the development of diabetes, and it is closely related to the presence and severity of coronary heart disease. Triglyceride glucose (TyG) index is a useful marker of insulin resistance; however, few studies have investigated the relationship between TyG and subclinical atherosclerosis. Therefore, we evaluated the association of TyG and subclinical coronary atherosclerosis as measured by coronary artery calcium score (CACS). Methods Our study included 30,776 participants (mean age of 41 years, 80.4% male) enrolled in a health screening program, in whom CACS were measured. Homeostasis model assessment of insulin resistance (HOMA-IR), TyG index, TyG-body mass index (BMI), and TyG-waist circumference (WC) were subsequently analyzed. Indices were calculated using the following formulae: HOMA-IR=fasting insulin (μU/mL)×fasting plasma glucose (FPG; mmol/L)/22.5; TyG index=Ln [TG (mg/dL)×FPG (mg/dL)/2]; TyG-BMI=TyG index×BMI; and TyG-WC=TyG index×WC. CACS was measured using multidetector computed tomography, and the presence of coronary artery calcification (CAC) was defined by CACS>0. Results The prevalence of CAC was 14.4% in the study population. Multivariate logistic regression analysis showed that participants with TyG-BMI in the highest tertile were 1.638 times more likely to have CAC after adjustment for other metabolic parameters compared with participants with TyG-BMI in the lowest tertile (odds ratio, 1.612; 95% confidence interval, 1.465 to 1.774). The receiver operating characteristics curve for prediction of CAC showed that TyG-WC index had a higher area under the curve (AUC=0.626) than other indices (AUCTyG=0.617, AUCTyG-BMI=0.616, AUCHOMA-IR=0.562). Conclusion TyG index predicted CAC better than other markers of insulin resistance, and could be a useful marker for predicting subclinical atherosclerosis