Seasonal Variation in Hemoglobin A1c in Korean Patients with Type 2 Diabetes Mellitus

A seasonal variation of glucose homeostasis in humans has been reported in various geographic regions. In this study, we examined seasonal variations in hemoglobin A1c (HbA1c) in patients with type 2 diabetes living in Korea. We analyzed 57,970 HbA1c values from 4,191 patients and the association of these values with ambient temperature for 3.5 yr. Overall, HbA1c exhibited its highest values from February to March and its lowest values from September to October (coefficient for cos t = -0.0743, P = 0.058) and the difference between the peak and nadir in a year was 0.16%-0.25%. A statistically significant seasonal variation was observed in the patients who were taking oral anti-diabetic drugs (OADs) without insulin treatment (coefficient for cos t = -0.0949, P < 0.05). The Spearman correlation coefficient between daily HbA1c values and the corresponding 3-month moving average ambient temperature was -0.2154 (95% confidence interval [CI]: -0.2711, -0.1580; P < 0.05). In conclusion, HbA1c values exhibited a seasonal variation in Korean patients with type 2 diabetes, with the highest values during the cold season, particularly in those who were treated with OADs, which should be taken into account in clinical practice for stable glucose control during the cold season.

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Hemoglobin A1c self-recording in the management of diabetes mellitus. A pilot study

HbA1c evaluates glycemic control 3-6 weeks retrospectively. To achieve improvements in glycemic control we have tested a patient-administered HbA1c control program in 12 (11 type I) diabetic patients. In the program, HbA1c was estimated once a month for 12 months and the results were mailed to the patient who recorded them in a specially designed HbA1c chart. The results in the probands were compared with 24 matched (22 type I) diabetic patients. The results showed that HbA1c fell significantly (p less than 0.01) during the year in the probands, from 8.84 +/- 1.12% to 7.48 +/- 0.95%, and was unchanged in the controls (8.41 +/- 1.78% and 8.17 +/- 1.74%, respectively). Accordingly, HbA1c self-recording improves glycemic control in diabetic patients.     

Intensity of long-term treatment with warfarin is influenced by seasonal variations

In a prospective study, which lasted 1 year and was performed on a large cohort of 800 patients treated at an outpatient anticoagulant clinic, we investigated possible seasonal variations in the intensity of the effect of warfarin treatment. For every season--winter, spring, summer and autumn--the mean prothrombin time reported as an international normalised ratio (INR) and the percentages of INR below 2.0 and above 4.0 were calculated. Significant seasonal variations in mean INR measurements were found, with the lowest values in summer and the highest values in autumn (F = 14.2, p < 0.0001). In addition, a trend toward a higher percentage of INR below 2.0 in summer and above 4.0 in autumn was observed. No significant differences were found between older (>65 years) and younger (<65 years) patients, although there was a trend toward more pronounced variations in younger patients. Consideration of seasonal variations might result in more accurate and safe guidance of warfarin treatment.     

The association between estimated average glucose levels and fasting plasma glucose levels

OBJECTIVE:

The level of hemoglobin A1c (HbA1c), also known as glycated hemoglobin, determines how well a patient''s blood glucose level has been controlled over the previous 8–12 weeks. HbA1c levels help patients and doctors understand whether a particular diabetes treatment is working and whether adjustments need to be made to the treatment. Because the HbA1c level is a marker of blood glucose for the previous 60–90 days, average blood glucose levels can be estimated using HbA1c levels. Our aim in the present study was to investigate the relationship between estimated average glucose levels, as calculated by HbA1c levels, and fasting plasma glucose levels.

METHODS:

The fasting plasma glucose levels of 3891 diabetic patient samples (1497 male, 2394 female) were obtained from the laboratory information system at the Izmir Bozyaka Training and Research Hospital in Turkey. These samples were selected from patient samples that had hemoglobin levels between 12 and 16 g/dL. The estimated glucose levels were calculated using the following formula: 28.7 x HbA1c – 46.7. Glucose and HbA1c levels were determined using hexokinase and high performance liquid chromatography (HPLC) methods, respectively.

RESULTS:

A strong positive correlation between fasting plasma glucose levels and estimated average blood glucose levels (r = 0.757, p<0.05) was observed. The difference was statistically significant.

CONCLUSION:

Reporting the estimated average glucose level together with the HbA1c level is believed to assist patients and doctors determine the effectiveness of blood glucose control measures.     

VCAM-1、AOPP、HbA1c和FBG在二甲双胍治疗糖尿病肾病患者中的意义

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Sensitivity of serum fructosamine in short term glycemic control

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The usefulness of glycated hemoglobin A1c (HbA1c) for identifying dysglycemic states in individuals without previously diagnosed diabetes

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社区糖尿病病人血糖控制及慢性并发症调查

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Sleep Duration and Glycemic Control in Patients with Diabetes Mellitus: Korea National Health and Nutrition Examination Survey 2007-2010

Short sleep duration has been reported to increase the risk of diabetes. However, the influence of sleep duration on glycemic control in diabetic patients has not been clarified. In this study we evaluated the association between sleep duration and glycemic control in diabetic patients. We analyzed the data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2010. Sleep duration was classified into five groups: <6, 6, 7, 8, and ≥9 h/day. Fasting blood glucose and HbA1c showed a U-shaped trend according to sleep duration. Sleep duration of 7 h/day had the lowest HbA1c (7.26%) among the subjects (P=0.026). In the older age group (≥65 yr), a sleep duration of 6 h/day was associated with the lowest HbA1c (7.26%). The adjusted odds ratio (OR) with a 95% confidence interval (CI) of worse glycemic control (HbA1c ≥7.0%) in group of sleep duration of ≥9 h/day was 1.48 (1.04-2.13) compared with the group of 7 h/day. This relationship disappeared after adjusting duration of diabetes (OR, 1.38; 95% CI, 0.93-2.03). Our results suggest that sleep duration and glycemic control in diabetic patients has U-shaped relationship which was mainly affected by duration of diabetes.     

2型糖尿病血管并发症患者血清可溶性细胞粘附分子-1和C-反应蛋白的检测分析

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Transient effect of the combination of insulin and sulfonylurea (glibenclamide) on glycemic control in non-insulin dependent diabetics poorly controlled with insulin alone

In a double-blind cross-over study we compared the effects of insulin plus glibenclamide, 5 mg twice daily, with insulin plus placebo during 8-week periods on metabolic parameters in 13 non-insulin dependent diabetic (NIDDM) patients poorly controlled with insulin alone. The combination therapy improved diabetic control as assessed by fasting blood glucose (p less than 0.001), 24-hour urinary glucose (p less than 0.01) and glycohemoglobin (HbA1) concentrations (p less than 0.05 at week 12). The effect tended to cease with time. Significantly higher C-peptide values were found during combination treatment than during insulin-placebo (p less than 0.01) and the changes in fasting C-peptide concentrations correlated positively with the changes in HbA1 concentrations (r = 0.56, p less than 0.05). There was no difference in glucagon concentrations, insulin binding to erythrocytes or insulin sensitivity between the two study periods. Neither did the combination therapy influence blood lipids significantly. The present study shows that the combination of insulin and glibenclamide may be of limited value in the treatment of NIDDM patients poorly controlled with insulin alone. However, thus far the long-term results are uncertain. In the absence of significant effects on insulin binding and insulin sensitivity, the improved diabetic control seems to be explained, at least partly, by glibenclamide-induced stimulation of insulin secretion.     

Haemoglobin A1c analysis in the management of patients with diabetes: from chaos to harmony

Effective management of patients with diabetes mellitus requires accurate assessments of blood glucose control. The best characterised marker of long term glycaemic control is whole blood haemoglobin A(1c) (HbA(1c)). Published clinical trials have identified quantitative and direct relationships between the HbA(1c) concentration and risks of diabetic microvascular complications. However, in order to practice evidence-based medicine, assays used to measure patient samples should ideally produce values comparable to the assays used in these trials. Numerous assays using chromatographic and immunological detection methods are used around the world. This paper briefly reviews the scientific evolution of HbA(1c) and its analysis, discusses the reasons why HbA(1c) assay standardisation is a challenge, describes the approaches that have been adopted to harmonise HbA(1c) assays, and addresses the current initiatives to standardise HbA(1c) globally. These efforts have established HbA(1c) as an essential component in the management of patients with diabetes mellitus and are likely to lead to the use of HbA(1c) in the screening/diagnosis of diabetes.     

Anti-atherosclerotic effects of etanercept in rheumatoid arthritis patients

Epidemic studies have shown that rheumatoid arthritis (RA) patients have shorter life expectancy than healthy persons, primarily due to cardiovascular events. The aim of our study was to explore inhibitory effects on atherosclerosis of RA patients by TNF-inhibitor etanercept (ETN). We studied six RA patients with moderate or high disease activity as defined by the European League Against Rheumatism (EULAR) disease activity score (DAS28-ESR) in spite of treatment with methotrexate (MTX) 8 mg/week. We measured their pulse wave velocity (PWV) before and after treatment with ETN 25 mg/week for one year. There were no additional medications other than ETN that might influence on atherosclerosis. Their PWV decreased in five of six patients and the average decreased from 1474.8 cm/sec to 1432.5 cm/sec. The average of DAS28-ESR score was significantly decreased from 5.56 to 2.87 and they achieved good response by the EULAR criteria. There were no significant changes in the blood pressure, serum lipid (total cholesterol and triglyceride) and HbA1c ; all values were within normal limits before and after ETN treatment. It is suggested that the improvement of PWV is due to anti-inflammatory effects, leading inhibition of atherosclerosis, of ETN in RA patients.     

吡格列酮对2型糖尿病患者血浆内皮素和一氧化氮水平的影响

目的:探讨吡格列酮对2型糖尿病(T2DM)患者血浆内皮素(ET)、一氧化氮(NO)的影响。方法:70名T2DM患者,随机双盲分为安慰剂组(A组,35例)和吡格列酮组(B组,35例),治疗3个月后,检测两组患者服药前后空腹血糖(FBG)、空腹胰岛素(FINS)、糖基化血红蛋白(HbA1C)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、ET和NO,并计算胰岛素敏感指数(ISI)。结果:治疗后吡格列酮组FBG、FINS、HbA1C、TG、ET明显下降(P<0.01),HDL-C、ISI、NO显著升高(P<0.01),ET与FINS呈正相关(r=0.478,P<0.01),与ISI呈负相关(r=-0.306,P<0.01),NO与FINS呈负相关(r=-0.371,P<0.01),与ISI呈正相关(r=0.447,P<0.01);安慰剂组各参数于治疗前后无显著性差异。结论:吡格列酮能够显著降低T2DM患者的ET水平,升高NO水平。     

平均红细胞血红蛋白含量对糖化血红蛋白结果的影响研究

目的 探讨平均红细胞血红蛋白含量（MCH）和红细胞平均体积（MCV）对糖化血红蛋白（HbA1c）影响情况。方法 本研究共纳入表观正常人群3369例,按照不同的HbA1c值分为三个组:A组:HbA1c≥6.5%（88例）、B组:6.5%＞HbA1c＞5.7%（615例）和C组:HbA1c≤5.7%（2666例）。按不同MCH分为:MCH≤26 pg的低值组120例、26 pg＜MCH＜34 pg的中值组3479例和MCH≥34 pg的高值组27例。采用偏相关分析红细胞参数对HbA1c检测结果的影响。进一步以HbA1c作为因变量,采用多元线性回归分析HbA1c的预测变量。结果 三组患者年龄、HbA1c、FPG、RBC、MCV、MCH和HCT值比较,差异均有统计学意义（P＜0.05）;A组MCV水平最高,其次是B组,C组MCV水平最低,三组间比较差异有统计学意义（P＜0.05）; MCH、MCV与HbA1c呈负相关（r=-0.217、-0.187, P＜0.001）;RBC与HbA1c呈正相关（r=0.161,P＜0.05）。通过逐步回归分析得出,FPG、RBC、性别、MCH和年龄可预测HbA1c值（r2=0.40,P＜0.05）。HbA1c随随MCH和MCV的增加而降低,随FPG、年龄和RBC的增加而升高。结论 当出现血糖水平与HbA1c值不一致时,可能是因为HbA1c受多种因素影响而不能反映真实血糖水平。     

保存温度和时间对糖化血红蛋白A1c样本稳定性的影响

目的探讨4种保存温度下糖化血红蛋白A1c(HbA1c)样本稳定时间。方法收集20例HbA1c水平不同的受试者样本,每例样本充分混匀后分装成45管,随机抽取一管样品立即测定,其余样本分组保存在室温(22～25℃)、冷藏(2～8℃)、低温冷冻(≤-20℃)、超低温冷冻(≤-70℃)条件下,并于保存第1、2、3、7、15和20天,第1、2、3和6个月及1年测定。HbA1c检测采用高效液相色谱(HPLC)法。观察4种保存条件下HbA1c平均水平随时间变化率,并采用不同统计方法和判别标准评价样本稳定性。结果按偏差小于6%判定,-70℃保存HbA1c可稳定1年;-20℃保存时,低浓度水平可稳定7 d,高浓度水平可稳定20 d,1年平均下降率为11.2%。室温及冷藏保存均可稳定3 d,至第7天HbA1c分别平均下降-9.1%和-7.1%。结论本研究为临床检验制定完善的HbA1c标本保存条件提供了依据,同时超低温冷冻保存更适用于开展HbA1c的大规模流行病学研究。     

糖尿病视网膜病变患者检测糖化血红蛋白的临床意义

目的探讨糖尿病视网膜病变 (DR)患者检测糖化血红蛋白 (HbA1c)的临床意义。方法对154例2型糖尿病患者DR情况和HbA1c水平进行检测。并对71例、病程5～10年的糖尿病患者正常眼底 (NDR)或单纯型糖尿病视网膜病变 (BDR)患者进行1年的随访 ,检测DR进展情况和HbA1c水平。结果DR组HbA1c高于NDR组。增殖型糖尿病视网膜病变 (PDR)组HbA1c高于BDR组。随访1年 ,视网膜病变进展组(A组)平均HbA1c高于视网膜病变稳定组(B组),差异具有统计学意义 (P<0.01)。结论DR的程度和进展与HbA1c增高有关     

Constant glomerular filtration rate in diabetic nephropathy. Correlation to blood pressure and blood glucose control

Twenty-one patients with diabetes of type I and diabetic nephropathy with reduced glomerular filtration rate (GFR) were followed prospectively with regard to GFR, proteinuria, blood pressure and glucosylated haemoglobin (HbA1). All patients were on antihypertensive treatment. The mean rate of decline in GFR was only 0.38 ml/month = 4.6 ml/year. In one third of the patients, GFR remained constant at a reduced level for at least 24 months. Mean plasma clearance of 51Cr-EDTA in this group was 48.3 +/- 14.6 ml/min/1.73 m2 body surface at entry and 48.0 +/- 13.6 at the time of evaluation. The patients with constant GFR had significantly less proteinuria and lower systolic as well as mean arterial pressure during the study than patients with falling GFR. They also had significantly lower mean HbA1 and fewer very high HbA1 values than patients who deteriorated. The data thus indicate that a combination of good metabolic control and effective blood pressure control may strongly delay the progression of renal insufficiency in diabetic nephropathy. They also show that low degree of proteinuria is a marker of good prognosis.     

Hemoglobin A1c testing alone does not sufficiently identify patients with prediabetes

Whether hemoglobin A(1c) (HbA(1c)) values are suitable for diagnosing diabetes has been debated. We sought to assess the prevalence of elevated HbA(1c) levels in a prediabetes patient population. Oral glucose tolerance tests and HbA(1c) levels were analyzed for patients entering a diabetes prevention program between January 1, 2007, and September 13, 2009. We calculated the percentage of patients with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) who had HbA(1c) values in the 6.0% to 6.4% range or in the 5.7% to 6.4% range. The mean age of the 242 patients was 62 years; 64.0% were women, and 88.0% were white. Isolated IFG was detected in about 56.2% of patients and combined IFG and IGT in about 37.2%. Only 28.5% of patients had HbA(1c) values in the 6.0% to 6.4% range, whereas 65.3% had values in the 5.7% to 6.4% range. Our data suggest that reliance on HbA(1c) testing alone to identify candidates for a diabetes prevention program would miss a substantial number of eligible patients.     

Improvement of Glycemic Control after Re-Emphasis of Lifestyle Modification in Type 2 Diabetic Patients Reluctant to Additional Medication

Purpose

The aim of this study is to observe glycemic changes after emphasizing the importance of lifestyle modification in patients with mild or moderately uncontrolled type 2 diabetes.

Materials and Methods

We examined 51 type 2 diabetic patients with 7.0-9.0% hemoglobin A1c (HbA1c) who preferred to change their lifestyle rather than followed the recommendation of medication change. At the enrollment, the study subjects completed questionnaires about diet and exercise. After 3 months, HbA1c levels were determined and questionnaires on the change of lifestyle were accomplished. We divided the study subjects into 3 groups: improved (more than 0.3% decrease of HbA1c), aggravated (more than 0.3% increase of HbA1c) and not changed (-0.3% ResultsAmong the total 51 subjects, 18 patients (35.3%) showed the decreased levels of HbA1c after 3 months with mean change of -0.74±0.27%, and HbA1c values of 11 patients (21.5%) were less than 7%. In addition, the HbA1c level was significantly reduced in patients who reportedly followed the lifestyle modification such as diet and exercise for 3 months, compared with the one obtained from patients who refused this lifestyle change (p=0.002).

Conclusion

In this study, 35.3% of the patients with mild or moderately uncontrolled type 2 diabetes showed the significant improvement of HbA1c levels after 3 months by simply regulating their daily diet and exercise without change of medication. This suggests that the lifestyle modification is significantly associated with the improvement of glucose control.