STUDY OF HbA1c AS A BIOMARKER IN DYSLIPIDEMIA AND ATHEROGENICITY IN TYPE 2 DIABETES MELLITUS

HbA1c is being used to assess the glycemic control for many years. This study was done to evaluate the importance of HbA1c in predicting dyslipidemia and atherogenecity in type 2 Diabetes. Methods: 200 type 2 diabetic patients were taken as subjects. Fasting and post meal blood sugar, Glycated haemoglobin (HbA1c), lipid profile, lipid ratios and atherogenic index of plasma(AIP) was analysed in these patients. The patients were divided into 2 groups depending on their HbA1c; Good Glycemic Control was defined as having HbA1c ≤ 7.0% and Poor Glycemic Control as HbA1c >7.0%. Results & Discussion: We found a significant increase in the levels of blood glucose, total serum cholesterol (TC), triglyceride, LDL cholesterol (LDL-C) and VLDL cholesterol (VLDL-C), TC/HDL-C, LDL-C/HDL-C, atherogenic index of plasma (AIP) and a significant decrease in the levels of HDL cholesterol (HDL-C) in patients with HbA1c >7% as compared to patients with HbA1c ≤ 7%. HbA1c had a direct and significant correlation with TC, TG, VLDL-C, LDL-C, TC /HDL-C, LDL-C/HDL-C, and an inverse correlation with HDL-C. AIP correlates with cardiovascular risk very well, and the association between HbA1c with various lipid parameters and atherogenic ratios suggests the importance of glycemic control in order to control dyslipidemia and future risk of cardiovascular disease in type 2 diabetics. KEYWORDS: Lipid profile; Type 2 diabetes mellitus; Glycosylated haemoglobin; Glycemic control, Atherogenic index of plasma

Boundary Conditions and Unitarity: the Maxwell-Chern-Simons System in AdS_3/CFT_2

We consider the holography of the Abelian Maxwell-Chern-Simons (MCS) system in Lorentzian three-dimensional asymptotically-AdS spacetimes, and discuss a broad class of boundary conditions consistent with conservation of the symplectic structure. As is well-known, the MCS theory contains a massive sector dual to a vector operator in the boundary theory, and a topological sector consisting of flat connections dual to U(1) chiral currents; the boundary conditions we examine include double-trace deformations in these two sectors, as well as a class of boundary conditions that mix the vector operators with the chiral currents. We carefully study the symplectic product of bulk modes and show that almost all such boundary conditions induce instabilities and/or ghost excitations, consistent with violations of unitarity bounds in the dual theory.Comment: 50+1 pages, 6 figures, PDFLaTeX; v2: added references, corrected typo

STUDY OF HbA1c AS A BIOMARKER IN DYSLIPIDEMIA AND ATHEROGENICITY IN TYPE 2 DIABETES MELLITUS

HbA1c is being used to assess the glycemic control for many years. This study was done to evaluate the importance of HbA1c in predicting dyslipidemia and atherogenecity in type 2 Diabetes. Methods: 200 type 2 diabetic patients were taken as subjects. Fasting and post meal blood sugar, Glycated haemoglobin (HbA1c), lipid profile, lipid ratios and atherogenic index of plasma(AIP) was analysed in these patients. The patients were divided into 2 groups depending on their HbA1c; Good Glycemic Control was defined as having HbA1c ≤ 7.0% and Poor Glycemic Control as HbA1c >7.0%. Results & Discussion: We found a significant increase in the levels of blood glucose, total serum cholesterol (TC), triglyceride, LDL cholesterol (LDL-C) and VLDL cholesterol (VLDL-C), TC/HDL-C, LDL-C/HDL-C, atherogenic index of plasma (AIP) and a significant decrease in the levels of HDL cholesterol (HDL-C) in patients with HbA1c >7% as compared to patients with HbA1c ≤ 7%. HbA1c had a direct and significant correlation with TC, TG, VLDL-C, LDL-C, TC /HDL-C, LDL-C/HDL-C, and an inverse correlation with HDL-C. AIP correlates with cardiovascular risk very well, and the association between HbA1c with various lipid parameters and atherogenic ratios suggests the importance of glycemic control in order to control dyslipidemia and future risk of cardiovascular disease in type 2 diabetics. KEYWORDS: Lipid profile; Type 2 diabetes mellitus; Glycosylated haemoglobin; Glycemic control, Atherogenic index of plasma

Spatially homogeneous Lifshitz black holes in five dimensional higher derivative gravity

We consider spatially homogeneous Lifshitz black hole solutions in five dimensional higher derivative gravity theories, which can be possible near horizon geometries of some systems that are interesting in the framework of gauge/gravity duality. We show the solutions belonging to the nine Bianchi classes in the pure R^2 gravity. We find that these black holes have zero entropy at non-zero temperatures and this property is the same as the case of BTZ black holes in new massive gravity at the critical point. In the most general quadratic curvature gravity theories, we find new solutions in Bianchi Type I and Type IX cases.Comment: 15 pages, no figure; v2, refs added, version to appear in JHE

Gravitational Chern-Simons Lagrangians and black hole entropy

We analyze the problem of defining the black hole entropy when Chern-Simons terms are present in the action. Extending previous works, we define a general procedure, valid in any odd dimensions both for purely gravitational CS terms and for mixed gauge-gravitational ones. The final formula is very similar to Wald's original formula valid for covariant actions, with a significant modification. Notwithstanding an apparent violation of covariance we argue that the entropy formula is indeed covariant.Comment: 39 page

The Weak Gravity Conjecture and the Viscosity Bound with Six-Derivative Corrections

The weak gravity conjecture and the shear viscosity to entropy density bound place constraints on low energy effective field theories that may help to distinguish which theories can be UV completed. Recently, there have been suggestions of a possible correlation between the two constraints. In some interesting cases, the behavior was precisely such that the conjectures were mutually exclusive. Motivated by these works, we study the mass to charge and shear viscosity to entropy density ratios for charged AdS5 black branes, which are holographically dual to four-dimensional CFTs at finite temperature. We study a family of four-derivative and six-derivative perturbative corrections to these backgrounds. We identify the region in parameter space where the two constraints are satisfied and in particular find that the inclusion of the next-to-leading perturbative correction introduces wider possibilities for the satisfaction of both constraints.Comment: 24 pages, 6 figures, v2: published version, refs added, minor clarificatio

Pathologies in Asymptotically Lifshitz Spacetimes

There has been significant interest in the last several years in studying possible gravitational duals, known as Lifshitz spacetimes, to anisotropically scaling field theories by adding matter to distort the asymptotics of an AdS spacetime. We point out that putative ground state for the most heavily studied example of such a spacetime, that with a flat spatial section, suffers from a naked singularity and further point out this singularity is not resolvable by any known stringy effect. We review the reasons one might worry that asymptotically Lifshitz spacetimes are unstable and employ the initial data problem to study the stability of such systems. Rather surprisingly this question, and even the initial value problem itself, for these spacetimes turns out to generically not be well-posed. A generic normalizable state will evolve in such a way to violate Lifshitz asymptotics in finite time. Conversely, enforcing the desired asymptotics at all times puts strong restrictions not just on the metric and fields in the asymptotic region but in the deep interior as well. Generically, even perturbations of the matter field of compact support are not compatible with the desired asymptotics.Comment: 36 pages, 1 figure, v2: Enhanced discussion of singularity, including relationship to Gubser's conjecture and singularity in RG flow solution, plus minor clarification

String Theory on Warped AdS_3 and Virasoro Resonances

We investigate aspects of holographic duals to time-like warped AdS_3 space-times--which include G\"odel's universe--in string theory. Using worldsheet techniques similar to those that have been applied to AdS_3 backgrounds, we are able to identify space-time symmetry algebras that act on the dual boundary theory. In particular, we always find at least one Virasoro algebra with computable central charge. Interestingly, there exists a dense set of points in the moduli space of these models in which there is actually a second commuting Virasoro algebra, typically with different central charge than the first. We analyze the supersymmetry of the backgrounds, finding related enhancements, and comment on possible interpretations of these results. We also perform an asymptotic symmetry analysis at the level of supergravity, providing additional support for the worldsheet analysis.Comment: 24 pages + appendice

The holographic principle

There is strong evidence that the area of any surface limits the information content of adjacent spacetime regions, at 10^(69) bits per square meter. We review the developments that have led to the recognition of this entropy bound, placing special emphasis on the quantum properties of black holes. The construction of light-sheets, which associate relevant spacetime regions to any given surface, is discussed in detail. We explain how the bound is tested and demonstrate its validity in a wide range of examples. A universal relation between geometry and information is thus uncovered. It has yet to be explained. The holographic principle asserts that its origin must lie in the number of fundamental degrees of freedom involved in a unified description of spacetime and matter. It must be manifest in an underlying quantum theory of gravity. We survey some successes and challenges in implementing the holographic principle.Comment: 52 pages, 10 figures, invited review for Rev. Mod. Phys; v2: reference adde

Corner contributions to holographic entanglement entropy

The entanglement entropy of three-dimensional conformal field theories contains a universal contribution coming from corners in the entangling surface. We study these contributions in a holographic framework and, in particular, we consider the effects of higher curvature interactions in the bulk gravity theory. We find that for all of our holographic models, the corner contribution is only modified by an overall factor but the functional dependence on the opening angle is not modified by the new gravitational interactions. We also compare the dependence of the corner term on the new gravitational couplings to that for a number of other physical quantities, and we show that the ratio of the corner contribution over the central charge appearing in the two-point function of the stress tensor is a universal function for all of the holographic theories studied here. Comparing this holographic result to the analogous functions for free CFT's, we find fairly good agreement across the full range of the opening angle. However, there is a precise match in the limit where the entangling surface becomes smooth, i.e., the angle approaches $\pi$, and we conjecture the corresponding ratio is a universal constant for all three-dimensional conformal field theories. In this paper, we expand on the holographic calculations in our previous letter arXiv:1505.04804, where this conjecture was first introduced.Comment: 62 pages, 6 figures, 1 table; v2: minor modifications to match published version, typos fixe