Microalbuminuria and nerve conduction velocity in type-I diabetics during conventional therapy and during continuous I.V. insulin infusion

Summary The objective of this study was to follow the development of microalbuminuria and nerve conduction velocity under continuous i.v. insulin therapy over a limited period of 4 months. For this purpose, 8 labile type I diabetics were selected (age 33±8 years, duration of diabetes 16±9 years) and treated conventionally with two insulin injections daily over 4 months. Afterwards, the same patients were treated with continuous i.v. insulin infusion and finally again with two injections daily over 4 months each. This procedure allowed each diabetic to serve as his own control. HbA₁, microalbuminuria, nerve conduction velocity and relative refractory period of the ulnar nerve were checked at montly intervals. During the continuous i.v. infusion over 4 months, blood sugar values were significantly lower, glucosuria had disappeared almost completely and the glycosylated hemoglobin had fallen to near normal values. The mean rate of albumin excretion was 16±5 μg/min at rest and 76±26 μg/min during exercise (normal: 3.9±0.4 and 4.8±1.2 μg/min, respectively) and did not change significantly. Nerve conduction velocity in the ulnar nerve rose significantly under i.v. insulin therapy from 47.9±0.6 m/sec to 52±0.6 m/sec. Similarly, the relative refractory period of the same nerve fell significantly from 3.7±0.2 to 1.9±0.1 msec (i.e. to within normal range). It is concluded that functional disturbances of peripheral nerve can regress by improved blood sugar control with continuous i.v. insulin infusion over 4 months. On the other hand, incipient microangiopathy measured as microalbuminuria remains unchanged over the same period of time. If an improvement is at all possible, considerably longer periods of euglycemia are likely to be necessary. Supported by Grant No. 3.964-0.80 from the Swiss National Science Foundation.     

代谢综合征患者血管内皮损伤标志物、C反应蛋白与胰岛素抵抗的关系

目的:观察代谢综合征(MS)患者血管内皮损伤标志物血管性假性血友病因子抗原(vWF:Ag)、凝血酶调节蛋白(TM)及超敏C反应蛋白(Hs-CRP)的水平变化及其与胰岛素抵抗的关系。方法:测定67例MS患者(其中合并冠心病31例)及35例健康对照组TM、vWF:Ag、Hs-CRP、空腹胰岛素(Fins)水平,计算胰岛素抵抗指数(IR)。结果:单纯MS组(B组)TM、vWF:Ag、Hs-CRP水平明显高于对照组(A组),P<0.05;MS合并冠心病组(C组)TM、vWF:Ag、Hs-CRP水平均高于A组和B组,差异有显著性统计学意义(P<0.05)。单因素直线相关分析表明TM、vWF:Ag、Hs-CRP与IR显著正相关(r分别为0.32、0.36、0.38)。结论:MS患者血管内皮损伤标志物、CRP水平升高,且与IR抵抗有关。     

Insulin, branched-chain amino acids, and growth failure in uremia

Insulin and branched-chain amino acid (BCAA) metabolism was studied in 14 adolescents with uremia on hemodialysis. Glucose tolerance was measured by intravenous glucose tolerance tests. Insulin sensitivity was measured by the euglycemia clamp technique. Insulin secretion during constant hyperglycemia was measured by the hyperglycemic clamp technique. Fasting plasma BCAA concentrations were compared with data from 8 adolescent controls, whereas insulin indices were compared with 8 young adults controls and with published normal data in adolescents. The patients could be further sub-divided into two groups with respect to their growth velocity standard deviation score (GVSDS). Group 1 consisted of 7 patients with GVSDS less than −2. This group demonstrated insulin resistance, glucose intolerance, and low insulin secretion. This group also had low plasma valine, leucine, and isoleucine concentrations compared with control values. Group 2 consisted of 7 patients with GVSDS more than −2. This group demonstrated insulin resistance, but normal glucose tolerance and normal insulin secretion. Plasma valine, leucine, and isoleucine concentrations in group 2 were not different from control values. Total plasma BCAA correlated with glucose tolerance index and with insulin secretion, but not with insulin sensitivity. Growth failure in uremia is associated with glucose intolerance, hypoinsulinemia, and low plasma BCAA concentrations. Impaired utilization of conventional energy sources leading to preferential oxidation of BCAA may contribute to reduced anabolism and growth failure in uremia. Received October 8, 1997; received in revised form February 3, 1998; accepted February 6, 1998     

The Effect of Intensive Insulin Therapy on the Insulin-regulatable Glucose Transporter (GLUT4) Expression in Skeletal Muscle in Type 1 Diabetes

Studies in normal man and rodents have demonstrated that the expression of the dominant glucose transporter in skeletal muscle, GLUT4, is regulated by insulin at supraphysiological circulating levels. The present study was designed to determine whether intensified insulin replacement therapy for 24 h given to patients with Type 1 diabetes in poor metabolic control was associated with an adaptive regulation of GLUT4 mRNA and protein levels in vastus lateralis muscle. Nine Type 1 diabetic patients with a mean HbA_1c of 10.3% were included in the protocol. After intensified treatment with soluble insulin for 24 h the fasting plasma glucose concentration decreased from 20.8 ± 2.3 (SD) to 8.7 ± 2.3 mmol 1^?1 whereas the fasting serum insulin level increased from 0.06 ± 0.02 to 0.17 ± 0.09 nmol 1^?1 However, despite a 2.8-fold increase in serum insulin levels and more than a halving of the plasma glucose concentration for at least 15 h no significant alterations occurred in the amount of GLUT4 protein (0.138 ± 0.056, poor control vs 0.113 ± 0.026 arb. units, improved control, p = 0.16) or GLUT4 mRNA (96432 ± 44985, poor control vs 81395 ± 25461 arb. units, improved control, p = 0.54). These results suggest, that in spite of evidence that high insulin levels affect GLUT4 expression in muscle, changes in serum insulin within the physiological range do not play a major role in the short-term regulation of GLUT4 expression in Type 1 diabetic patients.     

脂质比值与代谢综合征的关联及预测价值评价：基于多阶段横断面研究

背景 随着代谢性疾病发病率的上升,代谢综合征(MS)的预防与控制引起广泛的关注。而脂质比值是重要的筛查指标之一,与MS之间的关系成为热点研究话题。目的 基于贵州省多阶段横断面研究人群分析三酰甘油/高密度脂蛋白胆固醇(TG/HDL-C)、总胆固醇/HDL-C(TC/HDL-C)、低密度脂蛋白胆固醇/HDL-C(LDL-C/HDL-C)及非高密度脂蛋白胆固醇(non-HDL-C)与MS发病风险的关联及预测价值评价。方法 回顾性选取贵州省参与2010年全国疾病监测地区慢性病及危险因素调查、2013年中国慢性病及其危险因素监测、2015年中国成人慢性病与营养监测和2018年中国成人慢性病与营养监测的21 727例自然人群为研究对象,收集研究对象的基线资料,根据是否患有MS将研究对象分为MS组(n=4 981)和非MS组(n=16 746)。绘制受试者工作特征曲线(ROC曲线)分别评价男性和女性TG/HDL-C、TC/HDL-C、LDL-C/HDL-C和non-HDL-C对MS的预测价值。通过Delong检验比较脂质比值预测MS发生的ROC曲线下面积(AUC)的差异。采用多因素Logistic回...     

Amiloride-blockable Ca2+-activated Na+-permeant channels in the fetal distal lung epithelium

The Na⁺ transport function of alveolar epithelium represents an important mechanism for clearance of fluid in air space at birth. I observed the activity of two types of amiloride-blockable Na⁺-permeant cation channels in the apical membrane of fetal distal lung epithelium cultured on permeable filters for 2 days after harvesting of the cells from Wistar rats of 20 days' gestation (term = 22 days). One type was a nonselective cation (NSC) channel and had a linear current/voltage (I/V) relationship with a single-channel conductance of 26.9 ± 0.8 pS (n = 5). The other type was highly Na⁺ selective (i.e. Na⁺ channel) and had an inwardly rectifyingI/V relationship with a single-channel conductance of 11.8 ± 0.2 pS (n = 5) around resting membrane potential. The NSC channel was more frequently observed (1.37 ± 0.15 per patch membrane;n = 73) than the Na⁺ channel (0.15 ± 0.40 per patch membrane;n = 73). However, the open probability of the NSC channel was smaller than that of the Na⁺ channel. Both types of the channels were activated by cytosolic Ca²⁺, however the sensitivity to cytosolic Ca²⁺ was much higher in the Na⁺ channel than in the NSC channel. Furthermore, both types of the channels were blocked by amiloride or benzamil. The half-maximal inhibitory concentration (IC₅₀) of amiloride or benzamil of the Na⁺ channel was 1–2 M, while that of NSC channel was less than 1 M. Both channels were activated by insulin.     

胰岛素、可地松和已烯雌酚处理妊娠早期小鼠对其胚胎发育的影响

本文用不同剂量的胰岛素、可地松、已烯雌酚,作用于妊娠开始至80小时的昆明小鼠,然后观察胚胎早期(植入前)和胚胎晚期(妊娠18天)的胚胎数量、发育时期及其与黄体数相比成活率的变化。实验表明,用较大剂量激素处理后,早期胚胎的上述各项指标,均表现出十分明显的抑制效果。当剂量逐渐降低后,仍表现出不同程度的抑制作用,只是逐渐趋于正常。所用各种激素对晚期胚胎的影响,表现在除部分死亡外,存活者的生长和发育一直落后。说明妊娠早期小鼠体内某些激素的水平,不仅直接影响早期,而且也影响晚期胚胎的发育。     

Effects of exercise cessation on lipids and lipoproteins in distance runners and power athletes

Summary The purpose of this study was to determine the effects of short-term exercise cessation on lipid and lipoprotein profile and insulin sensitivity in highly trained runners (n=12; mean age 19.9 years) and power athletes (n=12; mean age 24.4 years). Following 14 days of exercise cessation, running time to exhaustion and maximal oxygen uptake decreased by 9.2% and 4.8% (P < 0.05) in the runners, while in the power athletes one repetition maximum squat and bench press did not change (P>0.05). No changes occurred in body composition. Data from a 2-h oral glucose tolerance test revealed an impairment of the glycemic state in all athletes (P<0.05). In contrast, exercise cessation did not significantly (P>0.05) alter plasma levels of cholesterol, triglycerides, and low density (LDL) and high density lipoprotein (HDL). No changes were observed in HDL₂, HDL_2b, and HDL₃ subfractions, LDL diameter, and qualitative LDL pattern (P>0.05). These data thus suggest that despite a decrease in insulin sensitivity, short-term exercise cessation, independent of exercise mode, was insufficient to alter plasma lipid and lipoprotein profiles in well-trained athletes.     

胰岛素对白细胞介素1产生及作用的影响

本文研究胰岛素对白细胞介素1(IL—1)的产生及其作用的影响.实验证实:腴岛素能促进LPS刺激的巨噬细胞IL—1的产生,并可增强胸腺细胞对Con A的反应.但用尼龙毛处理胸腺细胞除去粘附细胞后,胸腺细胞在无外源性IL—1存在时,对Con A的反应很弱.胰岛素不能增强经尼龙毛处理后的胸腺细胞对Con A的反应.加入外源性IL—1后,胰岛素可显著增强胸腺细胞对IL—1的应答,促进细胞增殖.这些结果表明。胰岛素是通过促进IL—1的产生及增强其作用来调节激活T细胞的.