Utility of HbA1c in the detection of subclinical post renal transplant diabetes

BACKGROUND: We hypothesized that the use of HbA1c testing would help identify postrenal transplant diabetes (PTDM). METHODS: In all, 199 adult kidney transplant recipients at least 3 months posttransplant without previous history of diabetes or elevated fasting blood sugar were studied. Medical history, a fasting blood glucose, calcineurin inhibitor blood level, and HbA1c were obtained. Primary outcome was the incidence of subjects with HbA1c > or =6.1%. The covariates were use of cyclosporine or tacrolimus, time posttransplant, body mass index (BMI) at transplant and change since transplant, current steroid dose, history of graft rejection, current fasting glucose, age, and race. Proportions were compared between HbA1c <6 and > or =6.1% using Fisher's exact test. Means were compared using Student's t test. Logistic regression was used to identify risk factors associated with elevated HbA1c. RESULTS: Twenty subjects (10.1%) had an elevated HbA1c. High normal fasting glucose (P=0.003) and African American race (P=0.08, marginally significant) were found to be associated with an elevated HbA1c. Subjects with normal and abnormal HbA1c levels were otherwise similar. There was no difference in HbA1c in tacrolimus versus cyclosporine treated subjects or in the percent of subjects with elevated HbA1c between these groups. CONCLUSIONS: HbA1c levels were found to be more a more sensitive test than fasting blood glucose levels in PTDM, with 10.1% of all patients and 19.4% of blacks found to have an elevated HbA1c. HbA1c testing should be considered as a screening test for PTDM, especially in African Americans.     

Preoperative hemoglobin A1c and postoperative glucose control in outcomes after gastric bypass for obesity

BACKGROUND: Hemoglobin A1c (HbA1c) is a reliable marker for long-term glycemic control in obese diabetic patients. Roux-en-Y gastric bypass improves HbA1c levels over time. However, it is not clear whether the preoperative HbA1c level is a predictor of the outcome in these patients. Our objectives were to understand the predictive capacity of the preoperative HbA1c level in gastric bypass patients at a single university-based Bariatric Center of Excellence. METHODS: We performed a retrospective review of 468 charts from 2006 to 2009 of patients who had undergone Roux-en-Y gastric bypass. Using their preoperative HbA1c status, the patients were categorized and the postoperative outcomes compared. RESULTS: Of the 468 patients reviewed, 310 (66.2%) had a HbA1c of <6.5% (group 1), 92 (19.4%) had a HbA1c of 6.5-7.9% (group 2), and 66 (14.1%) had a HbA1c level of >8.0% (group 3). No difference was found among the 3 groups in baseline body mass index, race, procedure type, length of stay, hospital cost, and smoking status. Groups 2 and 3 were associated with older age, male gender, and higher baseline creatinine. Groups 2 and 3 also had a proportionally greater inpatient postoperative blood glucose level. An elevated postoperative glucose level was independently associated with wound infection (P = .008) and acute renal failure (P = .04). Also, group 3 experienced worse outcomes, including less weight loss at 18 months and fewer diabetic remissions. Over time, however, the vast majority in all groups achieved excellent chronic glycemic control, with HbA1c <6.5% after Roux-en-Y gastric bypass. CONCLUSION: Poor preoperative glycemic control is associated with worse glucose level control postoperatively, fewer diabetic remissions, and less weight loss. An elevated mean postoperative glucose level is independently associated with increased morbidity.     

妊娠期糖尿病(A2级)的高危因素分析及早期诊断

目的探讨妊娠期糖尿病(GDM)妊娠早期血糖监测的时机和方法,以期提高GDM患者孕期保健指导的针对性,减少GDM的母婴危害。方法随机选择孕期需胰岛素控制血糖的GDM患者(GDMA2)100例为观察组,同期体检的仅需饮食控制血糖的GDM患者(GDMA1)100例为对照组。分析两组患者常见风险因素的差异,比较两组患者孕早期空腹血糖水平、孕24周口服葡萄糖耐量实验(OGTT)及糖化血红蛋白(HbA1c)结果的差异。结果纳入的GDM病例中孕前体重指数(BMI)25kg/m2者过半(GDMA1,58%;GDMA2,53%);GDMA2组患者有糖尿病家族史及不良孕产史的比例较高(P0.05),孕24周HbA1c水平及OGTT结果亦显著高于GDMA1组(P0.05);GDMA2孕妇24周HbA1c6.0%者的比例为81%,显著高于GDMA1孕妇的比例(28%)(P0.05)。结论对于有糖尿病家族史及既往不良孕产史的肥胖孕妇应加强早期血糖监测。在孕24周之前检测HbA1c可能有助于早期发现GDM。     

Hemoglobin A1c in early postpartum screening of women with gestational diabetes

AIM: To assess the utility of hemoglobin A1c (HbA1c) in the early postpartum screening of women with gestational diabetes mellitus (GDM).METHODS: Over a 3 years period, HbA1c estimations were undertaken in addition to and simultaneously with the traditional oral glucose tolerance test (OGTT), in 203 women with GDM as a part of early postpartum screening for dysglycaemia, at 6 wk post-partum. World Health Organization criteria was used for diagnosing diabetes: fasting blood glucose (FBG) ≥ 7.0 mmol/L and/or 2-h postprandial blood glucose (PPBG) ≥ 11.1 mmol/L and/or HbA1c ≥ 48 mmol/mol; and impaired glycaemiastate: impaired fasting glucose 6.1-6.9 mmol/L and/or impaired glucose tolerance 7.8-11.0 mmol/L and/or HbA1c: 42-47 mmol/mol.RESULTS: Mean FBG, 2-h PPBG and HbA1c were 4.9 ± 0.7 mmol/L, 5.6 ± 2.0 mmol/L and 38 ± 5 mmol/mol respectively. FBG, 2-h PPBG and HbA1c detected 6 (3%), 7 (3.5%) and 11 (5.4%) cases of diabetes respectively, and 11 (5.4%), 25 (12.3%) and 23 (11.3%) cases of pre-diabetes state respectively. HbA1c values ≥ 48 mmol/mol (≥ 6.5%) showed a diagnostic sensitivity of 71.4% and specificity of 98.5% for diabetes in comparison to OGTT in receiver operating characteristics curve analysis. At HbA1c cut-off 44 mmol/mol, sensitivity and specificity were 100% and 92.3% respectively [area under the curve: 0.98 (95%CI: 0.96-1.00)]. Sensitivity and specificity for detecting high risk “impaired glycaemia” state [HbA1c 42 mmol/mol (6.0%)] were 28% and 80%, respectively.CONCLUSION: HbA1c level ≥ 48 mmol/mol (≥ 6.5%) has reasonable sensitivity and high specificity in comparison to OGTT for early postpartum screening of diabetes in GDM. At 6^th week postpartum screening, if FBG is normal and HbA1c < 44 mmol/mol OGTT is not recommended.     

Relationship between glycosylated haemoglobin and mean plasma glucose concentration in cystic fibrosis.

BACKGROUND: HbA(1c) is recommended for monitoring glycaemic control in people with cystic fibrosis-related diabetes (CFRD). However the relationship between HbA(1c) and mean plasma glucose concentration (MPG) has not been established in CFRD, as in other forms of diabetes mellitus. METHODS: 20 people (13 male, 29.7+/-8.8 years, 10 CFRD) with cystic fibrosis (CF) underwent HbA(1c) measurement and 48 h continuous glucose monitoring for estimation of MPG. The relationship between HbA(1c) and MPG was established and compared to the reported relationship for type 1 diabetes. RESULTS: HbA(1c) was strongly correlated with MPG (R(2)=0.888, p<0.0001) in CF. The relationship of MPG to HbA(1c) was described by the equation MPG=(1.47xHbA(1c))-1.15, giving a 1.47 mmol L(-1) change in MPG per 1% change in HbA(1c). This equation predicts that MPG in people with CF and HbA(1c) <7.0% will be similar to MPG in people with type 1 diabetes who achieve the same HbA(1c) target. CONCLUSIONS: These results imply that HbA(1c)<7.0% will predict good blood glucose control in CF as in type 1 diabetes. However, although HbA(1c) predicts complications in type 1 diabetes, further studies are required to establish the relationship between HbA(1c) and diabetic complications in people with CFRD.     

HbA(1c) levels are genetically determined even in type 1 diabetes: evidence from healthy and diabetic twins.

HbA(1c), a measure of blood glucose regulation, reflects glucose levels in the preceding months. In diabetes, HbA(1c) levels predict the risk of microvascular complications. The aim of this study was to determine whether genetic factors could influence HbA(1c) levels in normal subjects and type 1 diabetic patients. We performed a classical twin study of HbA(1c) in healthy nondiabetic female twins and 42 monozygotic (MZ) and 47 dizygotic (DZ) pairs. Interclass correlations (r) were higher in MZ (r = 0.77) compared with DZ (r = 0.53) twin pairs, suggesting a substantial genetic effect; this was confirmed by quantitative genetic model fitting. Additive genetic effects (heritability) explained 62% (95% CI 47-75) of population variance in HbA(1c); the remainder was attributable to the influence of unique environment (23% [15-36]) and age (14% [5-28]). Multivariate modeling showed that genetic factors also have a substantial influence on fasting glucose levels (51%). However, HbA(1c) heritability could not be explained by genes in common with fasting glucose. In the patients with type 1 diabetes, HbA(1c) levels were correlated in 33 MZ twins concordant for diabetes (r = 0.68; P < 0.001) but also in 45 MZ twins discordant for the disease (r = 0.52; P < 0.001). These significant correlations for HbA(1c) in both concordant and discordant pairs indicate a diabetes-independent familial effect. Thus, HbA(1c) levels are largely genetically determined and independent of the genes influencing fasting glucose. Even in type 1 diabetes, familial (i.e., diabetes-independent) factors influence protein glycation, implying that familial factors may explain, in part, the risk for microvascular complications, as indicated by high HbA(1c) levels.     

Successful management of a type 2 diabetic donor in living-donor liver transplantation: a case report

A 50-year-old woman with a 4-year history of type 2 diabetes history was treated with nateglinide (270 mg/day) and metformin hydrochloride (500 mg/day). The recipient was her 55-year-old husband whose diagnoses were liver cirrhosis with type C chronic hepatitis (Child-Pugh C, score, 10; Model for End-Stage Liver Disease: 15), hepatocellular carcinoma (solitary, 2 cm), and hepatic encephalopathy. Her body weight was 50 kg and body mass index 21.6 kg/m2. Laboratory examinations showed fasting blood glucose of 110 mg/dL and hemoglobin A1c (HbA1c) of 6.6% upon admission. Right liver lobectomy was performed of a 563-g graft. Operative time was 253 minutes and blood loss 50 mL. She was discharged at postoperative day 9 without any complications. We changed nateglinide and metformin hydrochloride to insulin aspart or human insulin after admission. Blood glucose level was strictly controlled using a sliding scale of insulin. She received regular glucose check-ups at our outpatient clinic after discharge. She stopped using insulin and returned to nateglinide and metformin hydrochloride on postoperative day 25. Her blood glucose level was 80 to 150 mg/dL and HbA1c was 5.8% at 5 months after surgery. This type 2 diabetic living liver donor showed good control of the postoperative glucose level without exacerbation or diabetic complications.     

Time-in-range: a promising glycemic control metric for bariatric surgery

As a complication of obesity, type 2 diabetes (T2D) is a chronic disease that is difficult to manage. However, bariatric surgery makes it possible to alleviate T2D. While the existing generic index glycosylated hemoglobin (HbA1c) is a powerful tool for examining overall blood glucose levels, it still has some limitations as a daily measure of blood glucose levels and as a judge of the effectiveness of bariatric surgery. Using the time-in-range (TIR) measurement and its derivatives is a better way to evaluate short-term blood glucose fluctuations and can be used as a supplement to HbA1c. In this article, we discuss the utility and limitations of HbA1c and other indicators used during surgery. In addition, we mentioned TIR as a novel metric that can act as an accurate predictor of the risk of T2D complications and an index of preoperative risk assessment in bariatric surgery. In contrast to previous indicators, TIR has the advantage that it cannot be affected by caloric restriction to better reflect the patient's glucose level and the level of pancreatic islet function. On this basis, TIR is a promising indicator for both the diagnosis of diabetes and the preoperative and postoperative prediction and evaluation.     

The use of glycosylated haemoglobin measurements in the control of the diabetic patient.

Glycosylated haemoglobin (HbA1c) has recently been used as an indicator of long-term diabetic control. This study compares the efficacy of HbA1c measurements and postprandial blood glucose estimations in assessing diabetic control in 51 diabetic patients. It was found that the HbA1c levels reflected overall diabetic control significantly better than did a single postprandial blood glucose estimation. HbA1c measurements give considerable aid in the assessment of the longitudinal blood sugar control in the diabetic, and may be a useful indicator of the efficacy of diabetic treatment.     

Association of HbA1c with prevalent cardiovascular disease in the original cohort of the Framingham Heart Study.

We studied the cross-sectional relationship between HbA1c and cardiovascular disease (CVD) in the survivors of the original cohort of the Framingham Heart Study (n = 1045). HbA1c was significantly related to prevalent CVD among women but not men. HbA1c was also related to hypertension and to the ratio of total to high-density lipoprotein cholesterol levels. In regression analyses that controlled for these and other potential risk factors, HbA1c remained significantly related to CVD among women. The relative odds of CVD increased 1.39-fold (95% confidence interval 1.06-1.83) for increases in HbA1c of 1% (e.g., for HbA1c from 5 to 6%). The relationship was not weakened when known diabetic subjects or subjects taking beta-blocker or thiazide medications were excluded from analysis. In contrast, there was no significant relationship between "casual" blood glucose and prevalent CVD. Our results reveal a strong, significant, independent association between hyperglycemia, measured by HbA1c, and CVD among older women.