Human metabolism: pathways and clinical aspects

Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.     

Economic Evaluation of Factorial Trials: Cost-Utility Analysis of the Atorvastatin in Factorial With Omega EE90 Risk Reduction in Diabetes 2 × 2 × 2 Factorial Trial of Atorvastatin,Omega-3 Fish Oil,and Action Planning

ObjectivesWe applied principles for conducting economic evaluations of factorial trials to a trial-based economic evaluation of a cluster-randomized 2 × 2 × 2 factorial trial. We assessed the cost-effectiveness of atorvastatin, omega-3 fish oil, and an action-planning leaflet, alone and in combination, from a UK National Health Service perspective.MethodsThe Atorvastatin in Factorial With Omega EE90 Risk Reduction in Diabetes (AFORRD) Trial randomized 800 patients with type 2 diabetes to atorvastatin, omega-3, or their respective placebos and randomized general practices to receive a leaflet-based action-planning intervention designed to improve compliance or standard care. The trial was conducted at 59 UK general practices. Sixteen-week outcomes for each trial participant were extrapolated for 70 years using the United Kingdom Prospective Diabetes Study Outcomes Model v2.01. We analyzed the trial as a 2 × 2 factorial trial (ignoring interactions between action-planning leaflet and medication), as a 2 × 2 × 2 factorial trial (considering all interactions), and ignoring all interactions.ResultsWe observed several qualitative interactions for costs and quality-adjusted life-years (QALYs) that changed treatment rankings. However, different approaches to analyzing the factorial design did not change the conclusions. There was a ≥99% chance that atorvastatin is cost-effective and omega-3 is not, at a £20 000/QALY threshold.ConclusionsAtorvastatin monotherapy was the most cost-effective combination of the 3 trial interventions at a £20 000/QALY threshold. Omega-3 fish oil was not cost-effective, while there was insufficient evidence to draw firm conclusions about action planning. Recently-developed methods for analyzing factorial trials and combining parameter and sampling uncertainty were extended to estimate cost-effectiveness acceptability curves within a 2x2x2 factorial design with model-based extrapolation.     

hs-CRP、TAS联合血脂检测在早老性痴呆症诊断中的应用研究

[目的]研究超敏C反应蛋白（hs-CRP）、总抗氧化状态（TAS）联合血脂检测在早老性痴呆症诊断中的应用价值：[方法]选择浦东新区精神卫生中心早老性痴呆专科门诊患者54例，作超敏C反应蛋白、总抗氧化状态与血脂检测。[结果]与对照组比较，实验组hs-CRP、TAS差异非常显著，t1=4．55，t2=2．79，P1〈0．001，P2〈0．01；血脂中甘油三酯、低密度脂蛋白胆固醇、载脂蛋白B、Lp（a）差异显著；t1=3.01，P1〈0．01，t2=2．21，P2〈0．05，t3=2．64，P3〈0．01，t4=1．91，P4〈0．05。[结论]超敏C反应蛋白、总抗氧化状态联合血脂（甘油三酯、低密度脂蛋白胆固醇、载脂蛋白B、Lp（a））检测对实验室诊断早老性痴呆症具有较好敏感性和特异性，临床应用前景乐观。     

棕榈油对成人血脂和血小板功能的影响

报道了棕榈油（ＰＡ），花生油（ＰＥ）对血清总胆固醇水平（ＴＣ）在５．５～７．０ｍｍｏｌ／Ｌ的受试者血脂和血小板功能的影响。５１名受试者（男３１人，女２０人，年龄３０～６６岁之间）分为两组，一组男１５人，女１１人，称ＰＥ组；另一组男１６人女９人，称ＰＡ组，预备期３周，膳食以当地日常食用的花生油烹调，实验期６周。ＰＡ组受试者食用以棕榈油烹调的实验膳；ＰＥ组受试者仍食花生油烹调的膳食。脂肪约占膳食能量的３０％，其中６０％～６５％来自实验油。实验结果表明：与起始值相比，６周末ＰＡ组受试者血清ＴＣ，低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）和总胆固醇与高密度脂蛋白胆固醇比值（ＴＣ／ＨＤＬ－Ｃ）显著下降，血浆血栓素Ｂ２（ＴＸＢ２）／６－酮前列环素Ｆ１α、（６－ｋｅｔｏ－ＰＧＦ１α）比值显著下降，全血血小板聚集率未见显著变化。ＰＥ组受试者的血脂、血浆ＴＸＢ２、６－ｋｅｔｏ－ＰＧＦ１α及全血血小板聚集率等指标均未出现显著变化。提示，棕榈油作为我国居民家庭烹调用油并不会增加发生心血管疾病的危险。     

高脂血症时血清二乙基对硝基苯磷酸酯酶活性的变化

目的 :研究tritonWR 13 3 9致小鼠高脂血症时血清二乙基对硝基苯磷酸酯酶 (ParaoxonaseI ,PON 1)活性的变化及PON 1活性与血浆脂质含量之间的关系。方法 :在小鼠尾静脉注射tritonWR13 3 9后的 3h ,6h ,12h ,2 4h ,48h ,72h ,眼球摘除术取血 ,用酶标法测定小鼠血浆总胆固醇 (TC) ,甘油三酯 (TG ) ,高密度脂蛋白 -胆固醇 (HDL -C) ,载脂蛋白AI (ApoAI) ,载脂蛋白B (ApoB含量 ) ,并计算出ApoAI/ApoB ,HDL -C/TC比值 ,用分光光度计法测定PONI活性。结果 :TritonWR 13 3 9尾静脉注射后 3h ,小鼠血浆TC和TG含量即急剧增高 ,与对照组相比 ,P <0 .0 1,分别在注射后 2 4h和 3h达到峰值 ,随后逐渐下降 ,其中血浆TG含量在注射后 48h即恢复正常水平。tritonWR13 3 9尾静脉注射后 3h ,小鼠血浆HDL -C和ApoB含量急剧增高 ,与对照组相比 ,P <0 .0 5,分别在注射后 2 4h和 6h达到峰值 ,随后逐渐下降 ,分别在注射后 48h和 72h恢复正常水平。tritonWR13 3 9尾静脉注射后 3h ,小鼠血浆ApoAI含量即急剧降低 ,与对照组相比 ,P <0 .0 5,随后逐渐增高 ,在注射后 6h即恢复正常水平。tritonWR 13 3 9尾静脉注射后 3h ,小鼠血浆ApoAI/ApoB和HDL-C/TC比值减少 ,与对照组相比 ,P <0 .0 1,随后逐渐增高 ,其中ApoAI/ApoB比值在 72h恢复     

Leptin, lipid and lipid metabolism-related hormones in chronic renal failure in Arabia

SUMMARY: In patients with chronic renal failure (CRF), hyperleptinaemia has been widely reported, but the exact mechanisms leading to elevated leptin levels are unclear. Impaired renal clearance of leptin and the influence of other hormones may be important. In this study, we measured serum leptin levels in 150 patients on haemodialysis, peritoneal dialysis or in the predialysis phase of CRF. Furthermore, we measured plasma levels of insulin, growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as plasma levels of triacylglycerols and total low density lipoprotein (LDL)- and high density lipoprotein (HDL)-cholesterol. We observed significantly elevated levels of leptin, particularly in female patients, and leptin was shown to correlate significantly with insulin, total and LDL-cholesterol and log triacylglycerols. Leptin was inversely correlated with GH concentrations, but was not correlated with IGF-1 levels. Despite the multiple correlations established between leptin levels and other variables, only hyperinsulinaemia in CRF seems to be important as a determinator of leptin levels.     

Regional variations in intramyocellular lipid concentration correlate with muscle fiber type distribution in rat tibialis anterior muscle.

1H MR spectroscopy (MRS) has proved to be a valuable noninvasive tool to measure intramyocellular lipids (IMCL) in research focused on insulin resistance and type II diabetes in both humans and rodents. An important determinant of IMCL is the muscle fiber type, since oxidative type I fibers can contain up to three times more IMCL than glycolytic type II muscle fibers. Because these different muscle fiber types are inhomogeneously distributed in rodent muscle, in the present study we investigated the distribution of IMCL within the rat tibialis anterior muscle (TA) in vivo using single-voxel 1H MRS along with the muscle fiber distribution in the TA ex vivo determined from immunohistological assays. IMCL levels in the TA differed by up to a factor of 3 depending on the position of the voxel. The distribution of IMCL over the TA cross section was not random, but emerged in a pattern similar to the distribution of the predominantly oxidative muscle fiber types. Dietary interventions, such as high-fat feeding and 15 hr of fasting, did not significantly change this typical fiber type-dependent pattern of IMCL content. These results stress the importance of voxel positioning when single-voxel 1H MRS is used to study IMCL in rodent muscle.     

2型糖尿病患者血清抵抗素浓度与血脂代谢水平的临床意义

目的了解2型糖尿病患者血清抵抗素浓度与空腹血糖、血脂的关系。方法选择52例2型糖尿病患者和40例健康中老年人,分别分为糖尿病组和非糖尿病组,用竞争性酶联免疫吸附法测定各组空腹血浆抵抗素水平,同时检测空腹血糖、血脂各项指标。结果糖尿病空腹血浆抵抗素水平显著高于对照组(p<0.05)。抵抗素与甘油三脂、空腹血糖呈正相关关系(r=0.687,p<0.05,r=0.849,p<0.05),而抵抗素与其余各项血脂指标、性别之间无明显相关性。结论血清抵抗素水平与2型糖尿病关系密切,抵抗素水平可能影响体内能量代谢和平衡,与糖、脂代谢的关系更为密切。     

眼底动脉硬化与血压、血糖、血脂的多元分析与评估

目的探讨眼底动脉硬化与血压、血脂、血糖的相关性，评估中风危险度。方法对2004年5月至2008年10月就诊的患者335例，作为观察组，并与无症状的健康体检者180例作对照，动态检测眼底动脉硬化、血压、血糖、血脂的异常变化，并做综合量化评估。结果脑血管疾病与眼底动脉硬化、血压、血糖、血脂等因素密切相关。结论眼底动脉硬化、血糖、血脂、血压异常的量化评分，能够预估中风，以便采取预防性治疗。     

Human khat (Catha edulis) chewers have elevated plasma leptin and nonesterified fatty acids

In this study, the effect of regular khat (Catha edulis Forsk) chewing (200 and 400 g) in humans on plasma leptin, nonesterified fatty acid, triacyglycerol, and total cholesterol levels was investigated. The results presented show that khat chewing increases plasma leptin concentration particularly in individuals who chew 400 g of khat leaves. The significance of increased plasma leptin is in explaining the underlying mechanism of the observed effects associated with khat chewing such as loss of appetite, decreased body weight, and hyperthermia. The decreased body weight was evident from the significantly lower body mass index of the khat leaves chewers group as compared to the non–khat leaves chewers group (control). Moreover, like leptin, the plasma levels of nonesterified fatty acids were significantly higher in those chewing 400 g of khat leaves. On the other hand, the plasma levels of triacylglycerol were significantly lower in the 2 khat-chewers groups (200 and 400 g of khat leaves), whereas plasma cholesterol levels were not affected by the 2 levels of khat leaves used in this study. The significance of these results may suggest that khat leaves may contain a component(s) that has the ability to reduce body weight via decreasing appetite.