Weight Change and Risk of Developing Type 2 Diabetes

Objective: To examine the association between weight change and risk of type 2 diabetes and whether initial weight modifies the association. Research Methods and Procedures: This is a prospective cohort study of 20, 187 alumni from Harvard University and the University of Pennsylvania. At baseline in 1962 or 1966, men (mean age, 45.9 years) reported their weight, height, and other risk factors. They also had had their weight and height measured at university entry (mean age, 18.5 years). Participants were followed from baseline to 1998 for type 2 diabetes. Results: During follow‐up, 1223 men developed type 2 diabetes. Weight gain significantly increased the risk of this disease. The multivariate relative risks associated with BMI change from university entry to baseline of <?0.5, ±0.5, >0.5 to 1.0, >1.0 to 1.5, >1.5 to 2.0, >2.0 to 3.0, and >3.0 kg/m² per decade were 0.88, 1.00 (referent), 1.29, 2.09, 2.69, 4.67, and 7.02, respectively (p for trend < 0.0001). Even among men with a low initial BMI < 21 kg/m², weight gain significantly increased risk; the corresponding relative risks were (no cases), 1.00 (referent), 1.00, 1.93, 2.47, 4.82, and 7.68, respectively (p for trend < 0.0001). Discussion: A low initial BMI does not ameliorate the increase in risk of type 2 diabetes with weight gain. Avoidance of weight gain, even among lean individuals, is important to reduce the risk of this disease.     

Variance‐Component Analysis of Obesity in Type 2 Diabetes Confirms Loci on Chromosomes 1q and 11q

To study genetic loci influencing obesity in nuclear families with type 2 diabetes, we performed a genome‐wide screen with 325 microsatellite markers that had an average spacing of 11 cM and a mean heterozygosity of ～75% covering all 22 autosomes. Genotype data were obtained from 562 individuals from 178 families from the Breda Study Cohort. These families were determined to have at least two members with type 2 diabetes. As a measure of obesity, the BMI of each diabetes patient was determined. The genotypes were analyzed using variance components (VCs) analysis implemented in GENEHUNTER 2 to determine quantitative trait loci influencing BMI. The VC analysis revealed two genomic regions showing VC logarithm of odds (LOD) scores ≥1.0 on chromosome 1 and chromosome 11. The regions of interest on both chromosomes were further investigated by fine‐mapping with additional markers, resulting in a VC LOD score of 1.5 on chromosome 1q and a VC LOD of 2.4 on chromosome 11q. The locus on chromosome 1 has been implicated previously in diabetes. The locus on chromosome 11 has been implicated previously in diabetes and obesity. Our study to determine linkage for BMI confirms the presence of quantitative trait loci influencing obesity in subjects with type 2 diabetes on chromosomes 1q31‐q42 and 11q14‐q24.     

Urinary F2‐Isoprostanes Are Not Associated with Increased Risk of Type 2 Diabetes

Objective: Free radicals have been implicated in the etiology of type 2 diabetes. Cross‐sectional studies have demonstrated associations between oxidative damage and type 2 diabetes. However, no prospective data on this association are available. Research Methods and Procedures: A case control study was conducted within the prospective cohort of the Insulin Resistance Atherosclerosis Study: 26 cases who developed type 2 diabetes in the follow‐up period and 26 controls who remained free of type 2 diabetes were randomly selected. Oxidative status was assessed by measuring 2, 3‐dinor‐5, 6‐dihydro‐15‐F_2t‐isoprostane (F₂‐IsoPM) in baseline urine samples using gas chromatography/mass spectroscopy. Type 2 diabetes was defined by serial oral glucose tolerance tests and World Health Organization criteria. Results: Urinary F₂‐IsoPM varied between 0.18 and 2.60 ng/mg creatinine; 25th/50th/75th percentiles were 0.42, 0.60, and 0.89, respectively. A trend toward higher levels were observed in women and in persons with impaired glucose tolerance at baseline (p = 0.1). F₂‐IsoPM increased with BMI (r = 0.36, p = 0.01). After adjustment for age, gender, baseline impaired glucose tolerance status, and BMI, F₂‐IsoPM levels were inversely associated with development of type 2 diabetes: odds ratio = 0.32 (95% confidence interval, 0.12 to 0.81) for the difference between the 75th and 25th percentiles. Discussion: These results suggest that oxidative damage is not a cause of type 2 diabetes. Positive cross‐sectional associations of F₂‐IsoPM with the risk factors for diabetes, BMI, and impaired glucose tolerance and inverse associations with development of type 2 diabetes indicate that F₂‐IsoPM might reflect a compensatory mechanism.     

Weight Cycling and the Risk of Developing Type 2 Diabetes among Adult Women in the United States

Objective: To assess the role of weight cycling independent of BMI and weight change in predicting the risk of developing type 2 diabetes. Research Methods and Procedures: A six‐year follow‐up of 46, 634 young and middle‐aged women in the Nurses’ Health Study II was conducted. Women who had intentionally lost ≥20 lbs at least three times between 1989 and 1993 were classified as severe weight cyclers. Women who had intentionally lost ≥10 lbs at least three times were classified as mild weight cyclers. The outcome was physician‐diagnosed type 2 diabetes. Results: Between 1989 and 1993, ～20% of the women were mild weight cyclers, and 1.6% were severe weight cyclers. BMI in 1993 was positively associated with weight‐cycling status (p < 0.001). During 6 years of follow‐up (1993 to 1999), 418 incident cases of type 2 diabetes were documented. BMI in 1993 had a strong association with the risk of developing diabetes. Compared with women with a BMI between 17 and 22 kg/m², those with a BMI between 25 and 29.9 kg/m² were approximately seven times more likely to develop diabetes, and those with a BMI ≥35 kg/m² were 63 times more likely to be diagnosed with type 2 diabetes. After adjustment for BMI, neither mild (relative risk = 1.11, 95% confidence interval, 0.89 to 1.37) nor severe (relative risk = 1.39, 95% confidence interval, 0.90 to 2.13) weight cycling predicted risk of diabetes. Discussion: Weight cycling was strongly associated with BMI, but it was not independently predictive of developing type 2 diabetes.     

2型糖尿病合并下肢动脉粥样硬化的危险因素

下肢动脉粥样硬化是2型糖尿病(T2DM)患者最常见的大血管并发症之一。作为T2DM患者严重的慢并发症之一,下肢动脉粥样硬化可引起糖尿病足的发生,严重情况下可导致足坏疽。因此,阐明T2DM合并下肢动脉粥样硬化的危险因素,早期预防和治疗糖尿病合并下肢动脉粥样硬化症,不仅提高了患者的生活质量,而且减轻了家庭和社会的经济负担,具有较大的现实意义。影响T2DM患者下肢动脉粥样硬化的因素错综复杂,分为不可调控的和可调控的因素,不可调控的危险因素包括年龄、种族、遗传等,可调控的危险因素包括吸烟、高血糖、高血脂、高血压,以及近年提出的肥胖、胰岛素抵抗、高纤维蛋白血症、炎症等。本文就T2DM合并下肢动脉粥样硬化的危险因素做一综述。     

2型糖尿病患者下肢血管病变的危险因素分析

目的:探讨2型糖尿病患者发生下肢血管病变的危险因素.方法:回顾性分析我院2009年12月～2011年12月收治的98例2型糖尿病患者的临床资料,通过彩色多普勒超声检查其下肢血管,按下肢血管有无病变将其分为单纯2型糖尿病租和2型糖尿病合并下肢血管病变组,通过非条件Logistic回归分析导致2型糖尿病患者发生下肢血管病变的危险因素.结果:彩色多普勒超声检查结果显示,98例2型糖尿病患者中,61例发生不同程度下肢血管病变,占62.24％.与单纯2型糖尿病组比较,下肢血管病变组患者年龄、病程、收缩压及低密度脂蛋白胆固醇的差异均有统计学意义(P＜0.05),经非条件Logistic回归分析,患者的年龄、病程、SBP及LDL-L是下肢血管病变的独立危险因素(P＜0.05).结论:2型糖尿病患者下肢血管病变的发生与患者的年龄、病程、血压及血脂情况密切相关.     

2型糖尿病易感基因的连锁和关联研究

2型糖尿病（T2DM）是由于胰岛素抵抗和β细胞分泌缺陷导致高血糖的一种复杂多基因疾病。遗传因素在T2DM的发生发展中起着重要的作用,其遗传率估计为70％～80％。鉴定2型糖尿病基因将有助于阐明其发病机制,发展更好的诊断、预防和治疗策略。2型糖尿病易感基因的鉴定方法主要有候选基因关联研究和全基因组连锁分析。有3种类型的候选基因：功能候选基因、图位候选基因和表达候选基因。虽然许多候选基因与T2DM的关联分析已经进行,但多数都没有得到一致的重复,过氧化物酶体增殖物激活受-γ,体和β-细胞ATP敏感性钾通道基因是目前最好重复的基因。迄今为止,T2DM的全基因组扫描已在20多个不同的群体中进行,包括欧洲人、美国白人、墨西哥裔美国人、美国本地印度人、非洲裔美国人和亚洲人,这些研究鉴定了一些与T2DM相关的QTLs区域。与T2DM显著和证实连锁的区域包括1q25、2q37．3q28、3p24、6q22、8p23、10q26、12q24、18p11、20q13等,与T2DM提示连锁的区域有1q42、2p21、2q24、4q34、5q13、5q31、7q32、9p24、9q21、10p14、11p13、11q13、12q15、14q23、20p12、Xq23等。鉴定这些区域的T2DMQTLs基因及其作用机制是未来的主要挑战。把DNA微阵列和蛋白质组学技术结合起来应用于传统的连锁分析和关联研究,研究基因-基因间、基因-环境间的互作和多个基因对T2DM的加性效应和综合作用,进一步加强国际协作,T2DM的遗传机制可望在不远的将来得到阐明。本文总结了2型糖尿病基因鉴定的现状,重点在一些得到重复的区域和未来的展望。     

Linkage and Association Studies of the Susceptibility Genes for Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) is a complex disease characterized by hyperglycemia, insulin resistance, and impaired insulin secretion. T2DM is under strong genetic control. Identification and characterization of genes involved in determining T2DM will contribute to a greater understanding of the pathogenesis of T2DM, and ultimately might lead to the development of better diagnosis, prevention and treatment strategies. Efforts to identify T2DM susceptibility genes have focused on candidate gene approach (association studies) and genome-wide scans (linkage analyses). In this article, we review the current status for mapping and identification of genes for T2DM, with a focus on some promising regions (or genes) and future prospects.     

PAI-1 Gene 4G/5G polymorphism and risk of type 2 diabetes in a population-based sample

Elevated plasma levels of plasminogen activator inhibitor-1 (PAI-1) increase risk for type 2 diabetes. The PAI-1 4G/5G polymorphism is a major genetic determinant of plasma PAI-1 levels, with 4G/4G homozygotes having elevated PAI-1 levels relative to 5G allele carriers. These observations suggest the hypothesis that the PAI-1 4G/5G polymorphism could be a genetic risk factor for diabetes. We tested this hypothesis among 2169 participants of the Framingham Offspring Study followed for seven examinations over 26 years for 216 cases of type 2 diabetes. PAI-1 4G/4G homozygotes (genotype frequency, 27.4%) were not at significantly (p > 0.05) increased risk of incident diabetes compared with 5G allele carriers and did not have elevated levels of diabetes-related quantitative traits including BMI, fasting plasma glucose, or fasting insulin. In proportional hazards regression models accounting for correlation among siblings, with the 5G/5G genotype as the referent, the hazard ratio for incident diabetes for 4G/5G carriers was 0.93 (95% confidence interval, 0.68 to 1.28) and for 4G/4G carriers was 1.20 (95% confidence interval, 0.83 to 1.92). Results were not altered by further adjustment for sex or levels of BMI, triglycerides, or PAI-1. We conclude that the PAI-1 4G/5G polymorphism is not an important genetic risk factor for type 2 diabetes in this community-based sample. Elevated PAI-1 levels may be associated with an increased risk for diabetes as a marker for underlying endothelial dysfunction rather than by a direct effect of genetically mediated elevated levels.     

Structural scaffold for eIF4E binding selectivity of 4E‐BP isoforms: crystal structure of eIF4E binding region of 4E‐BP2 and its comparison with that of 4E‐BP1

To clarify the higher eukaryotic initiation factor 4E (eIF4E) binding selectivity of 4E‐binding protein 2 (4E‐BP2) than of 4E‐BP1, as determined by Trp fluorescence analysis, the crystal structure of the eIF4E binding region of 4E‐BP2 in complex with m⁷GTP‐bound human eIF4E has been determined by X‐ray diffraction analysis and compared with that of 4E‐BP1. The crystal structure revealed that the Pro47‐Ser65 moiety of 4E‐BP2 adopts a L ‐shaped conformation involving extended and α‐helical structures and extends over the N‐terminal loop and two different helix regions of eIF4E through hydrogen bonds, and electrostatic and hydrophobic interactions; these features were similarly observed for 4E‐BP1. Although the pattern of the overall interaction of 4E‐BP2 with eIF4E was similar to that of 4E‐BP1, a notable difference was observed for the 60–63 sequence in relation to the conformation and binding selectivity of the 4E‐BP isoform, i.e. Met‐Glu‐Cys‐Arg for 4E‐BP1 and Leu‐Asp‐Arg‐Arg for 4E‐BP2. In this paper, we report that the structural scaffold of the eIF4E binding preference for 4E‐BP2 over 4E‐BP1 is based on the stacking of the Arg63 planar side chain on the Trp73 indole ring of eIF4E and the construction of a compact hydrophobic space around the Trp73 indole ring by the Leu59‐Leu60 sequence of 4E‐BP2. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

老年2型糖尿病患者发生严重低血糖相关危险因素分析

目的:研究老年2型糖尿病患者发生严重低血糖的相关危险因素。方法:选取2013年7月到2014年7月我院收治的老年2型糖尿病患者200例,根据是否发生严重低血糖将患者分为非低血糖组(138例)和低血糖组(62例),比较两组临床资料。结果:低血糖组和非低血糖组体重指数、住院时间以及糖尿病病程比较差异具有统计学意义(P0.05);低血糖组心脑血管疾病药物联用率显著高于非低血糖组,二甲双胍应用率显著低于非低血糖组,胰岛素应用率以及口服降糖药(OAD)和胰岛素的联合应用率显著高于非低血糖组,两组比较差异具有统计学意义(P0.05);低血糖组低钾血症发生率显著高于非低血糖组,肾功能有关的指标显著高于非低血糖组,低血糖组白细胞和中性粒细胞显著高于非低血糖组,两组比较差异具有统计学意义(P0.05);Logistic多因素回归分析可知,病程超过10年、胰岛素应用以及和OAD联用、果糖胺低于2.5 mmol/L、白细胞升高、肾功能受损均和严重低血糖发生具有相关关系。结论:病程超过10年、胰岛素应用以及和OAD联用、白细胞升高、果糖胺低于2.5 mmol/L、肾功能受损均和严重低血糖发生有关,在行降糖治疗时应该谨慎评估上述危险因素。     

Plasma Adiponectin Levels in High Risk African‐Americans with Normal Glucose Tolerance,Impaired Glucose Tolerance,and Type 2 Diabetes**

Objective: We studied plasma adiponectin, insulin sensitivity, and insulin secretion before and after oral glucose challenge in normal glucose tolerant, impaired glucose tolerant, and type 2 diabetic first degree relatives of African‐American patients with type 2 diabetes. Research Methods and Procedures: We studied 19 subjects with normal glucose tolerance (NGT), 8 with impaired glucose tolerance (IGT), and 14 with type 2 diabetes. Serum glucose, insulin, C‐peptide, and plasma adiponectin levels were measured before and 2 hours after oral glucose tolerance test. Homeostasis model assessment‐insulin resistance index (HOMA‐IR) and HOMA‐β cell function were calculated in each subject using HOMA. We empirically defined insulin sensitivity as HOMA‐IR < 2.68 and insulin resistance as HOMA‐IR > 2.68. Results: Subjects with IGT and type 2 diabetes were more insulin resistant (as assessed by HOMA‐IR) when compared with NGT subjects. Mean plasma fasting adiponectin levels were significantly lower in the type 2 diabetes group when compared with NGT and IGT groups. Plasma adiponectin levels were 2‐fold greater (11.09 ± 4.98 vs. 6.42 ± 3.3811 μg/mL) in insulin‐sensitive (HOMA‐IR, 1.74 ± 0.65) than in insulin‐resistant (HOMA‐IR, 5.12 ± 2.14) NGT subjects. Mean plasma adiponectin levels were significantly lower in the glucose tolerant, insulin‐resistant subjects than in the insulin sensitive NGT subjects and were comparable with those of the patients with newly diagnosed type 2 diabetes. We found significant inverse relationships of adiponectin with HOMA‐IR (r = ?0.502, p = 0.046) and with HOMA‐β cell function (r = ?0.498, p = 0.042) but not with the percentage body fat (r = ?0.368, p = 0.063), serum glucose, BMI, age, and glycosylated hemoglobin A1C (%A1C). Discussion: In summary, we found that plasma adiponectin levels were significantly lower in insulin‐resistant, non‐diabetic first degree relatives of African‐American patients with type 2 diabetes and in those with newly diagnosed type 2 diabetes. We conclude that a decreased plasma adiponectin and insulin resistance coexist in a genetically prone subset of first degree African‐American relatives before development of IGT and type 2 diabetes.     

北京市2型糖尿病患者抑郁状况的横断面调查及其危险因素分析

目的:探讨北京市2型糖尿病(T2DM)患者抑郁症发病情况及其危险因素,为T2DM合并抑郁症的防治提供依据。方法:采取横断面调查的方法对2016年1月-2016年12月中国人民解放军总医院健康管理研究院体检中患T2DM的3000例患者随机抽取1200例进行调查,所有患者进行Zung抑郁自评量表(SDS)测评,根据SDS结果分为T2DM合并抑郁症组和T2DM非抑郁症组。应用单因素和多因素Logistic回归法分析T2DM合并抑郁症的危险因素。结果:北京市T2DM患者抑郁症患病率为21.93%,不同性别T2DM患者抑郁症患病率比较无统计学差异(P0.05)。单因素分析显示,北京市T2DM患者抑郁症发病与糖尿病病程、运动情况、胰岛素治疗、并发症情况、糖化血红蛋白有关(P0.05),与饮食控制、血糖监测情况、收缩压、舒张压、胆固醇、甘油三酯无关(P0.05)。多因素Logistic回归分析显示糖尿病病程≥10年、胰岛素治疗、并发症≥3个、糖化血红蛋白≥8.0%是北京市T2DM患者抑郁症发病的危险因素(P0.05),经常运动是北京市T2DM患者抑郁症发病的保护性因素(P0.05)。结论:北京市T2DM患者抑郁症患病率为21.93%,糖尿病病程≥10年、胰岛素治疗、并发症≥3个、糖化血红蛋白≥8.0%是北京市T2DM患者抑郁症发病的危险因素,经常运动是北京市T2DM患者抑郁症发病的保护性因素。     

Comparison of Regional Fat Distribution and Health Risk Factors in Middle‐Aged White and African American Women: The Healthy Transitions Study

Objective: Both ethnicity and menopause appear to influence intra‐abdominal fat distribution. This study evaluated intra‐abdominal fat distribution and obesity‐related health risks in perimenopausal white and African American women. Research Methods and Procedures: Baseline data from a longitudinal study of changes in body composition and energy balance during menopause are reported. Healthy women (55 African Americans and 103 whites) who were on no medication and had at least five menstrual cycles in the previous 6 months were recruited. Body composition was assessed by DXA, and visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed by computed tomography scan. SAT was divided into deep and superficial layers demarcated by the fascia superficialis. Results: African American women were slightly younger (46.7 ± 0.2 vs. 47.7 ± 0.2 years, p = 0.002) and fatter (42.4% ± 1.0% vs. 39.4% ± 0.8% body fat, p = 0.02) than white women. In unadjusted data, African Americans had significantly more total abdominal fat and total, deep, and superficial SAT than whites. After adjustment for percent body fat and age, only total and superficial SAT remained significantly higher in African Americans. VAT although slightly less in African American women, did not differ significantly by race. In multiple regression analysis, VAT was the strongest predictor of serum lipids, glucose, and insulin in women of both races, although superficial SAT was significantly associated with fasting glucose in whites. Conclusions: Middle‐aged African American women have larger SAT depots, adjusted for total body fatness, but do not differ from white women with regard to VAT. The complexity of the relationship between abdominal fat and metabolic risk is increased by ethnic differences in such associations.     

2 型糖尿病治疗药物研究进展

2 型糖尿病（T2DM）是一种代谢障碍性疾病。传统抗糖尿病药物具有不同程度的副作用,如低血糖、胃肠道反应、体重增加、 心血管风险等,因此开发作用于新靶点和新作用机制的T2DM 治疗新药成为当前研究的热点。目前基于新靶点设计的糖尿病治疗新药有 些已上市,且获得良好的降糖效果,但大部分药物仍处于临床或临床前研究阶段,其疗效和安全性有待进一步临床验证。综述传统抗糖 尿病药物、T2DM 药物新靶点及基于新靶点设计的抗糖尿病新药的研究进展。     

与2型糖尿病相关糖复合物中糖链结构变化

2型糖尿病是一种全球性严重危害人类健康的慢性代谢性疾病.在2型糖尿病患者和动物的血液、尿液及受损组织中,糖链的结构均发生了不同程度的变化.本文对近年来有关2型糖尿病发生、发展过程中糖蛋白、蛋白聚糖和糖脂中糖链的结构变化进行综述,为2型糖尿病的诊断及其相关药物的研发提供有用的参考.     

Pharmacoresistant Cav2·3 (E‐type/R‐type) voltage‐gated calcium channels influence heart rate dynamics and may contribute to cardiac impulse conduction

Voltage‐gated Ca²⁺ channels regulate cardiac automaticity, rhythmicity and excitation–contraction coupling. Whereas L‐type (Ca_v1·2, Ca_v1·3) and T‐type (Ca_v3·1, Ca_v3·2) channels are widely accepted for their functional relevance in the heart, the role of Ca_v2·3 Ca²⁺ channels expressing R‐type currents remains to be elucidated. We have investigated heart rate dynamics in control and Ca_v2·3‐deficient mice using implantable electrocardiogram radiotelemetry and pharmacological injection experiments. Autonomic block revealed that the intrinsic heart rate does not differ between both genotypes. Systemic administration of isoproterenol resulted in a significant reduction in interbeat interval in both genotypes. It remained unaffected after administering propranolol in Ca_v2·3(?|?) mice. Heart rate from isolated hearts as well as atrioventricular conduction for both genotypes differed significantly. Additionally, we identified and analysed the developmental expression of two splice variants, i.e. Ca_v2·3c and Ca_v2·3e. Using patch clamp technology, R‐type currents could be detected in isolated prenatal cardiomyocytes and be related to R‐type Ca²⁺ channels. Our results indicate that on the systemic level, the pharmacologically inducible heart rate range and heart rate reserve are impaired in Ca_v2·3 (?|?) mice. In addition, experiments on Langendorff perfused hearts elucidate differences in basic properties between both genotypes. Thus, Ca_v2·3 does not only contribute to the cardiac autonomous nervous system but also to intrinsic rhythm propagation. Copyright © 2012 John Wiley & Sons, Ltd.