线粒体DNA ND1基因nt3394 T→C突变与老年人2型糖尿病

目的：了解线粒体烟酰胺腺嘌呤脱氧核苷酸（NADH）脱氢酶第一亚单位（ND1）基因中339位点T→C突变与我国老年人2型糖尿病的关系。方法：收集无血缘关系的208例老年2型糖尿病患者，同时以180例无糖尿病家族史的老年糖耐量正常者作为对照，用聚合酶链反应扩增。限糖尿病患者，同时以180例无糖尿病家族史的老年糖耐量正常者作为对照，用聚合酶链反应扩增、限制性内切酶HaeⅢ消化进行点突变筛选。结果：发现9例患者存在线粒体DNA ND1基因3394位点T→C突变（4．3％），非糖尿病者中仅有1例突变（0．6％），两组比较差异有显著性（P＜0．05）。结论：线粒体DNA ND1基因中3394位点T→C突变可能与我国老年人2型糖尿病的发病有关。     

糖尿病与线粒体ND1点突变的关系

目的探讨湖北省线粒体基因的热点突变区域ND1点突变(3243,3316,3394,3593)与老年2型糖尿病的关系。方法采用聚合酶链反应-限制性片段长度多态性法对无血缘关系的134例老年糖尿病患者及152例正常对照个体的血细胞线粒体DNA进行突变分析。结果病例组中3316G→A点突变率为3·7%,3394T→C点突变发生率为3·0%,而对照组3316和3394的突变率分别为0·66%和0,3394组间差异比较均有显著性(P<0·05)。病例组中3593点突变发生率为0·75%,对照组未见该突变,两组间差异无显著性。未发现3243的突变。结论线粒体DNA3394T→C突变与老年线粒体糖尿病的发生与发展有关,并起着重要作用。     

母系遗传糖尿病线粒体基因突变的观察

采用PCR-RFLP、DNA直接测序技术对14个有明确母系遗传史的糖尿病家系进行线粒体基因筛查。结果14例先证者及对照组均未检出A3243G等3个线粒体基因突变位点。家系成员发现携带G3316A突变，T3394C突变，三例均为健康携带者。结论G3316A突变、T3394C突变不是糖尿病的独立致病因素。     

家族性糖尿病人群中线粒体ND-1基因点突变的分析研究

目的了解线粒体ND-1基因mt3316G→A、mt3394T→C变异在中国家族性糖尿病人群中的发生率及其临床特点。方法应用PCR-RFLP结合直接测序方法对随机抽取的无亲缘关系的770个糖尿病家系的先证者及309例非糖尿病对照者进行线粒体基因mt3316G→A、mt3394T→C变异的筛查。结果在糖尿病先证者组中发现17例（2.21%）mt3316G→A变异,18例（2.34%）mt3394T→C变异;在正常对照组中分别发现5例（1.62%）和6例（1.94%）变异携带者,变异的发生率在两组间差异无统计学意义。在糖尿病先证者组见到2例同时携带上述两种变异者。伴mt3316G→A或mt3394T→C突变的糖尿病组与无该变异的糖尿病组之间的临床特点（年龄、体质指数、胰岛素抵抗指数）比较差异无统计学意义。结论线粒体ND-1基因mt3316G→A,mt3394T→C变异可能不是中国人线粒体糖尿病发病的致病原因,而是中国人线粒体的基因多态。     

线粒体DNA变异与老年2型糖尿病患者易感性的相关性

目的 研究湖北地区老年2型糖尿病(T2DM)患者中线粒体基因突变的发生率及其相关性.方法 采用PCR-RFLP、基因测序技术,对175例老年T2DM患者和200例糖耐量正常的健康老年对照组进行检测.结果 MIND1 3316(G→A)、MTTL1 3243(A→G)、MIND13394( T→C)、MIND14216(T→C) MIND14164(A→G)和MIND2 5178( T→C)变异率分别为3.26％、2.72％、1.71％、4％、34.9％;对照组检出3316(G→A)突变2例(0.99％)、4164 5例(0.99％)、5718(T→C)变异64例(32.3％),未检出3394、4216的点突变;两组间3394(T→C)变异率差别有统计学意义(P＜0.05);且T2DM组5178A基因型血清TC水平低于5178C基因型(P＜0.05),但TG、LDL-C、HDL-C、apoA、apoB、Lp(a)水平两组无统计学意义.结论 3394( T→C)与老年T2DM患者的易感性有一定关联,5178(T→C)变异与湖北地区老年汉族人T2DM的脂代谢相关.     

线粒体基因碱基变异与老年2型糖尿病的易感性研究

目的 探讨线粒体基因3243和3426位点碱基变异与老年2型糖尿病的易感性。方法采用聚合酶链反应-限制性片段长度多态性（PCR—RFLP）方法，对186例老年2型糖尿病患者和170例健康对照者的线粒体基因3243和3426位点进行筛选分析，并以DNA测序方法确认。结果 两组均未检出3243A→G变异和3426A→G变异，测序中发现糖尿病组3290T→C变异1例。结论 线粒体基因3243A→G变异和3426A→G变异可能与湖北地区老年2型糖尿病的易感性无关联性。     

175例2型糖尿病患者线粒体基因变异分析

本文采用PCR-RFLP及DNA测序方法对湖北省汉族人群无血缘关系的175例2型糖尿病患者及200例正常对照个体的线粒体DNA进行突变分析。两组间仅3394T→C突变发生率的差异有统计学意义。推测该位点变异与汉族人群中的线粒体糖尿病的发生发展有关。     

老年2型糖尿病患者线粒体ND1基因常见突变位点的快速筛查

2型糖尿病是慢性代谢疾病，呈高龄人群高发病率的特点，尤其是持续高血糖所引发的心血管疾病、终末期肾病等并发症严重困扰着老年2型糖尿病患者。线粒体基因缺陷是其遗传易感因素之一，在诸多报道的突变位点中，以位于tRNA leu（UUR）基因3243（A—G）突变及ND1基因的3316（G→A）、3394（T→C）和3593（T→C）突变最为常见。我们以老年2型糖尿病为研究对象，     

2型糖尿病相关线粒体ND1基因的荟萃分析

目的利用荟萃分析评价线粒体NDI基因点突变与2型糖尿病发病的相关性。方法通过文献检索收集1999年1月至2008年9月在中英文公共数据库检索或已经发表的线粒体NDl基因点突变与2型糖尿病相关的病例对照研究。按照本研究纳入和排除标准,筛选线粒体NDl基因G3316A、T3394C 2个点突变作为研究对象。应用STATA 9.0 SE软件对各研究进行综合分析。结果在病例对照研究中,线粒体G3316A、T3394C相对危险度合并OR值和95%CI分别为:2.70(1.39～5.24)、3.44(1.41～8.40)。结论线粒体G3316A、T3394C点突变可能与中国人2型糖尿病遗传易感性相关。     

线粒体DNA ND-1基因点突变与2型糖尿病的关系

2型糖尿病患者中线粒体DNA（mtDNA)3316G→A，3316G→A，3394T→C突变频率分别为3.9%(6/152)和5.3%(8/152)，显著高于正常对照者及冠心病患者，提示mtDNA3316G→A，3394T→G突变与2型糖尿病相关。     

Novel mutations found in mitochondrial diabetes in Chinese Han population

Mitochondria provide cells with most of the energy in the form of ATP. Mutations in mitochondrial DNA (mtDNA) are associated with type 2 diabetes mellitus (T2DM) because ATP plays a critical role in the production and the release of insulin. To systematically determine mutant loci and to investigate their association with T2DM in Chinese Han population, 17 commonly reported mutant loci were screened in 236 cases of T2DM and 240 normal controls by PCR-RFLP, allele-specific PCR (AS-PCR) and DNA sequencing methods. Biological softwares were used to analyze the secondary structure of DNA, RNA and the corresponding proteins for missense mutations. Sixteen mutant loci were detected in total, of which five were novel, GenBank accession nos. were DQ092356, DQ473644 and DQ473645; they were mainly in16S rRNA, ND1 and ND4 gene. There was significant difference between the two groups for ND1 and ND4 genes mutation frequencies (ND1: P=0.001, OR=3.944, 95% CI 1.671-9.306; ND4: P=0.010, OR=5.818, 95% CI 1.275-26.537). No significant association was observed between the two groups for 5178A/C polymorphisms (P=0.418). Our study suggested that T3394C and A12026G might be associated with T2DM in Chinese Han population, and T2DM with mtDNA variant should be considered mitochondrial diabetes.     

Variation of mitochondrial gene and the association with type 2 diabetes mellitus in a Chinese population

Mitochondrial DNA (mtDNA) variants have been implicated in many diseases including diabetes mellitus. To explore whether these genetic variants contribute to the susceptibility for type 2 diabetes mellitus (T2DM) in a Chinese population, a total of 184 T2DM cases and 279 matched healthy controls were recruited. PCR restriction fragment length polymorphism (PCR-RFLP) analysis and DNA sequencing were used to determine the variants of mtDNA (including T16189C, G3316A, T3394C, A14693G, A3243G and C1310T). Some of them were further analyzed by mfold or tRNA-scan-SE software. A homoplastic A14693G, for the first time, was found in 4 of 184 Chinese cases, the frequency of A14693G and T3394C was 2.17% and 2.72%, respectively, in patients but not in the controls. Secondary structure prediction revealed that there were obvious conformational changes in T3394C mutant ND1 versus wild type and A14693G mutant tRNA(Glu) protein versus wild type, providing additional clues to the disease pathogenesis although A3243G and C1310T mutations were not detected in any patients in the two groups. The 16189 variant among type 2 diabetes was more prevalent than in controls (36.9% versus 28.7%, P=0.039), and stepwise multiple regression analysis showed that the 16189 variant was an independent factor contributing to HOMA-IR (R(2)=0.043, P=0.037). Our results suggest that the mutations of T3394C and A14693G may contribute to genetic predisposition to T2DM, with the T16189C variant being associated with insulin resistance.     

中国人群线粒体基因C3394T及A12026G突变与2型糖尿病相关性的Meta分析

目的 研究中国人群线粒体基因C3394T及A12026G突变与T2DM相关性。方法检索中国知网、万方、维普、Pubmed数据库,对2001-2013年中国人群线粒体基因C3394T、A12026G突变与T2DM相关性的随机对照试验（RCTs）文献进行检索。经质量评价和资料提取后,对符合质量标准的RCTs进行Meta分析。结果 共纳入11个RCTs。7个RCTs结果显示,C3394T突变合并OR（95% CI）为7.48（3.17-17.76）,4个RCTs结果显示,A12026G突变合并OR（95% CI）为1.88（1.14-3.11）。 结论 中国人群线粒体基因C3394T及A12026G突变与T2DM有相关性,且是其发病的危险因素之一。     

老年2型糖尿病患者动态血糖监测分析

目的 探讨老年2型糖尿病患者的动态血糖波动特点.方法 对老年2型糖尿病患者(老年组)92例和中青年2型糖尿病患者(中青年组)58例进行动态血糖监测,对比分析两组患者血糖谱特征及老年不同糖化血红蛋白(HbA1c)水平糖尿病患者的血糖谱特征.结果 (1)老年组与中青年组比较,血糖波动系数(BGFC)增大[(2.68±1.00)mmol/L对(2.12±0.74) mmol/L,t=-3.691,P＜0.001];餐后血糖漂移幅度(PPGE)增大,早餐后分别为 ( 5.96±2.47) mmol/L对(5.11±2.44) mmol/L(t=-2.058,P＜0.05),晚餐后分别为(5.17±2.15) mmol/L对 (4.16±2.28) mmol/L(t=-2.730,P＜0.01);餐后血糖达峰时间延长,早餐后(112.5±29.7) min对(97.0±27.2) min(t=-3.225,P＜0.01),中餐后(140.0±39.7)min对 (118.1±42.6) min(t=-3.195,P＜0.01);低血糖发生频率增加(26.3%对5.5%,P＜0.05);最大血糖漂移幅度(LAGE)增大,分别为(9.66±2.48) mmol/L对(8.40±3.13) mmol/L(t=-2.720,P＜0.01);(2)老年组患者随HbA1c下降,低血糖发生率增加(P＜0.05);随 HbA1c升高,血糖波动幅度增大;(3)HbA1c与空腹血糖(FBG)、日平均血糖(MBG)、高血糖时间比(PT7.8、PT11.1)、最低血糖(LBG)、最高血糖(HBG)、BGFC、PPGE、LAGE均正相关(r=0.899～0.289,均P＜0.001);逐步回归分析显示,MBG、FBG、PT7.8与HbA1c独立相关(校正的R2=0.807,P＜0.05).结论 老年2型糖尿病患者血糖波动幅度大,易发生餐后高血糖和夜间低血糖,动态血糖监测能较详细地显示患者的血糖水平及波动特征.

Abstract：

Objective To investigate the characteristics of the blood glucose fluctuation in elderly patients with type 2 diabetes mellitus (T2DM). Methods The 92 elderly patients with T2DM (the elderly group) and 58 young and middle-aged patients with T2DM (the non-elderly group) were monitored using the continuous glucose monitoring system(CGMS). The characteristics of glucose profiles of the two different age groups, and of the different glycosylated hemoglobin (HbA1c) level groups in the elderly were comparatively analyzed. Results (1)There was no significant difference in HbA1c level between the elderly group and the non-elderly group. Compared with the non-elderly group, the elderly group showed the increases in blood glucose fluctuant coefficient [BGFC, (2.68±1.00) mmol/L vs. (2.12±0.74) mmol/L, t=-3.691, P＜0.001], in postprandial glucose excursion (PPGE) of breakfast and supper [(5.96±2.47) mmol/L vs. (5.11±2.44) mmol/L, t=-2.058, P＜0.05; (5.17±2.15) mmol/L vs. (4.16±2.28) mmol/L, t=-2.730, P＜0.01], in the time to postprandial glucose peak of breakfast and lunch [(112.5±29.7) min vs. (97.0±27.2) min, t=-3.225, P＜0.01; (140.0±39.7) min vs. (118.1±42.6) min, t=-3.195, P＜0.01], in the frequency of hypoglycemia (26.3% vs. 5.5%, P＜0.05), and showed the largest amplitude of glycemic excursions [LAGE, (9.66±2.48) mmol/L vs.(8.40±3.13) mmol/L, t=-2.720, P＜0.01]. (2)In the elderly, along with decreased HbA1c, the incidence of hypoglycaemia increased (P＜0.05); And along with increased HbA1c, the amplitude of blood glucose fluctuation increased. There were significant differences in BGFC, PPGE of breakfast and lunch, and LAGE among different HbA1c level groups (P＜0.01, P＜0.05, P＜0.05, P＜0.001). (3)HbA1c was positively correlated with FBG, mean blood glucose (MBG), percentage of time at glycemia (PT7.8, PT11.1), the lowest blood glucose (LBG), the highest blood glucose (HBG), BGFC, PPGE and LAGE (r=0.899-0.289, all P＜0.001). Multiple stepwise regression analysis indicated that MBG, FBG and PT7.8 was the independent influential factor of HbA1c (adjusted R2=0.807, P＜0.05). Conclusions The elderly patients with T2DM are at a particularly high risk for postprandial hyperglycemia and nocturnal hypoglycemic episodes, CGMS could show glucose fluctuation characters of T2DM patients diurnally, and provide a clinical basis for reasonable therapy.     

高分辨率超声评价早期2型糖尿病患者足背动脉病变和血管内皮功能

目的 应用高分辨率超声对早期2型糖尿病(T2DM)患者足背动脉形态学、血流动力学及血管内皮功能的改变进行观察. 方法 检测25例老年初发T2DM患者、35例非老年初发T2DM患者及35例老年健康者和30例非老年健康者足背动脉的变化,并进行统计学分析. 结果 (1)反应性充血时,老年T2DM组足背动脉内径变化百分率(10.52±2.79)%较老年对照组(15.43±4.69)%明显减低(P<0.01),非老年T2DM组(12.89±4.68)%较非老年对照组(17.97±4.61)%明显减低(P<0.01),老年T2DM组与非老年T2DM组比较亦有减低(P<0.05);含服硝酸甘油后,老年T2DM组(12.40±3.23)%较老年对照组(16.11±5.74)%明显减低(P<0.01).(2)T2DM组较同龄对照组足背动脉内-中膜厚度(IMT)明显增厚(P<0.01),舒张早期反向血流峰值流速(PRV)和舒张末期血流速度(EDV)明显减低(P<0.01),搏动指数(PI)减低(P<0.05);各组间收缩期峰值流速(PSV)的差异均无统计学意义(P>0.05).(3)T2DM组足背动脉PI与反应性充血时和舌下含服硝酸甘油后内径变化百分率呈显著正相关(相关系数分别为0.79和0.71,P<0.01).结论 高分辨率超声检查可及早发现T2DM患者足背动脉形态学、血流动力学改变及血管内皮功能受损情况,可将其作为T2DM大血管并发症的首选检查方法 .     

老年阻塞性睡眠呼吸暂停低通气综合征患者临床特点分析

目的 探讨老年阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者的临床特点、易患因素及睡眠结构特点. 方法选择2006年至2009年在我院睡眠监测中心经多导睡眠监测(PSG)确诊的老年OSAHS患者163例,依呼吸暂停低通气指数(AHI)分为轻、中、重度组,按照体质指数(BMI)分为正常体质量组和肥胖组,对老年OSAHS患者的临床特点、睡眠监测指标及睡眠结构进行分析,以同期就诊的190例非老年OSAHS患者为对照组. 结果 (1)OSAHS患者中肥胖人群比例为79.1%,其中非老年组肥胖患者比例为83.6%,老年组为70.3%,两组间比较差异有统计学意义(P＜0.05).(2)老年组的中重度患者比例低于非老年组,两组间AHI、最低血氧饱和度(LSaO2)、血氧饱和度(SaO2)＜90%的累积时间占总睡眠时间的百分比(%TRTSaO2＜90%)比较,差异有统计学意义(P＜0.05).(3)老年患者睡眠结构紊乱程度较非老年组严重,非快动眼睡眠(NREM)Ⅲ+Ⅳ期比例明显减少,呼吸性醒觉反应增加.(4)老年患者临床症状不典型,个体差异明显,并存症多.结论 老年OSAHS患者的病情明显轻于非老年患者,但睡眠结构紊乱明显重于非老年患者.

Abstract：

Objective To investigate the clinical and pdysomnographic characteristics and related factors of obstructive sleep apnea hypopnea syndrome (OSAHS) in elderly patients. Methods The 163 elderly patients with OSAHS confirmed by polysomnography were classified into obesity group and non-obesity group according to body mass index (BMI). All cases were grouped into mild,moderate and severe groups according to the apnea hypopnea index (AHI) and night SaO2. The 190non-elderly OSAHS patients were as control group at the same time. The clinical and polysomnographic characteristics were recorded and analyzed. Results (1)The proportion of obesity in OSAHS patients was 79. 1%, there was significant difference between the elderly-obesity group and non-elderly-obesity group (70.3% vs. 83.6%, P＜0.05). (2)The proportions of moderate and severe OSAHS patients were lower in elderly group than in non-elderly group. There were significant differences in AHI, the lowest arterial O2 saturation (LSaO2) and % TRT SaO2 ＜90% between the two groups (all P＜0.05). (3)The sleep architecture disturbance was significantly severer in elderly group than in non-elderly group. The percentages of non-rapid eye movementsleep (NREM sleep)stage Ⅲ-Ⅳ sleep were significantly decreased, and the arousal was significantly increased. (4) The syndrome of OSAHS in elderly group was untypical and the clinical complication was increased.Conclusions The elderly OSAHS patients are less severe than non-elderly group, but the elderly patients have worse sleep architecture disturbance and more complications such as hypertension and other cardiovascular diseases.     

Mutation of Mitochondrial DNA in Livers From Patients With Alcoholic Hepatitis and Nonalcoholic Steatohepatitis

Background: In alcoholic hepatitis (Al-Hep) and nonalcoholic steatohepatitis (NASH), triglycerides accumulate in hepatocytes. We examined the hypothesis that mutations in mitochondrial DNA may take place by mitochondrial overwork, resulting in dysfunction of mitochondria.
Subjects and Methods: Subjects of this research were 8 cases each of Al-Hep, NASH, and fatty liver (FL). Total DNA was extracted from the biopsied liver samples. DNA fragments were amplified by PCR and DNA sequences determined in the control and coding regions of mitochondrion.
Results: When the numbers of mutations per 1,000 bases of mitochondrial DNA were compared between each group, no significant differences were found among D-loop, HV1, and HV2 mitochondrial DNA regions. However, there were significantly more mutations in ND1 and COII of Al-Hep and NASH than in FL, and mutations were comparatively at random. Neither a region in which mutations were focused nor differences among the groups were recognized. When details of the base mutation in a control region were investigated by group, the transition type of mutation between T:A≪–≫C:G occurred in at least 70%. Also, a transition-type mutation was found mostly in a coding region, which was similar to the mutation pattern in the control region, except for the ND1 and COII regions where there were hardly any mutations.
Conclusions: As gene mutations of mitochondrial DNA appeared frequently in Al-Hep, and also in NASH, mitochondrial dysfunction caused by mutation in mitochondrial DNA may be involved in the pathogenesis of both diseases.     

Mitochondrial gene mutations in gestational diabetes mellitus

Mitochondrial DNA mutations have been implicated in many diseases including diabetes mellitus. Although gestational diabetes mellitus (GDM) has been suggested to have genetic determinant and to be etiologically indistinct with non-insulin-dependent diabetes mellitus (NIDDM), its association with mitochondrial gene mutations is still unknown. In this study, 137 patients with GDM and 292 non-diabetic pregnant controls were examined for mitochondrial DNA mutations from the nucleotide 3130-4260 encompassing tRNA-Leu gene and adjacent NADH dehydrogenase 1 gene by polymerase chain reaction, single-stranded conformation polymorphism, restriction fragment length polymorphism and DNA sequencing. One heteroplasmic mutation at the position of 3398 (T-C), which changed a highly conserved methionine to threonine in NADH dehydrogenase subunit 1, was identified in 2.9% GDM patients but not in the controls, indicating its association with GDM (P = 0.01). Two novel mutations, a heteroplasmic C3254A and a homoplasmic A3399T, were also found in GDM subjects, the functional meaning of which merits further investigation. G3316A and T3394C mutations implicated in NIDDM, were seen at higher frequencies in patients with GDM than the controls. Our results suggest that mitochondrial DNA mutations may contribute to the development of GDM in some patients.