Myostatin serum levels in children with type 1 diabetes mellitus

PURPOSE

Type 1 diabetes mellitus (T1DM) can cause several complications, among them myopathy, which can appear even in adolescents. This is of importance, since skeletal muscle is the largest of the insulin-sensitive tissues and thus plays a significant role in glucose homeostasis. A prime regulator of skeletal muscle mass is myostatin, a protein which has a negative role in skeletal muscle development but also in glucose homeostasis, causing insulin resistance. Since myopathy is a complication of T1DM and myostatin is a fundamental regulator of skeletal muscle and is also involved in glucose homeostasis, we investigated the serum levels of myostatin in children with T1DM.

METHODS

We determined myostatin serum levels using ELISA in 87 children with T1DM aged 10.62 ± 3.94 years, and in 75 healthy children aged 10.46 ± 3.32 years old.

RESULTS

Myοstatin was significantly elevated in T1DM compared to the healthy control children (23.60 ± 7.70 vs 16.74 ± 6.95 ng/ml, p < 0.0001). Myostatin was not correlated with body mass index (BMI) SD or hemoglobin A1c (HbA1c).

CONCLUSION

Children with T1DM have significantly higher serum levels of myostatin compared to healthy children of the same age and BMI SD. The elevated myostatin in T1DM could reflect impaired muscle function and/or glucose metabolism, or could represent a homeostatic mechanism.

Diagnosing type 2 diabetes using Hemoglobin A1c: a systematic review and meta-analysis of the diagnostic cutpoint based on microvascular complications

AIMS

Diabetic microvascular complications of retinopathy, nephropathy and neuropathy may occur at hemoglobin A1c levels (HbA1c) below the 6.5% (48 mmol/mol) diagnostic threshold. Our objective was to assess the validity of the HbA1c diagnostic cutpoint of 6.5% based upon published evidence of the prevalence of retinopathy, nephropathy and neuropathy as markers of diabetes.

METHODS

Data Sources PubMed, Embase, Cochrane, Scopus and CINAHL from 1990-March 2019, grey literature sources. Study Selection All studies reported after 1990 (to ensure standardized HbA1c values) where HbA1c levels were presented in relation to prevalence of retinopathy, nephropathy or neuropathy in subjects not known to have diabetes. Data Extraction Studies were screened independently, data abstracted, and risk of bias appraised. Data Synthesis Data were synthesized using HbA1c categories of < 6.0% (< 42 mmol/mol), 6.0-6.4% (42-47 mmol/mol) and ≥ 6.5% (≥ 48 mmol/mol). Random-effects meta-analyses were conducted for retinopathy, nephropathy and neuropathy prevalence stratified by HbA1c categories. Random-effects multivariable meta-regression was conducted to identify predictors of retinopathy prevalence and sources of between-study heterogeneity.

RESULTS

Pooled mean prevalence was: 4.0%(95% CI: 3.2-5.0%) for retinopathy, 10.5% (95% CI: 4.0-19.5%) for nephropathy, 2.5% (95% CI: 1.1-4.3%) for neuropathy. Mean prevalence when stratified for HbA1c < 6.0%, 6.0-6.4% and ≥ 6.5% was: retinopathy: 3.4% (95% CI: 1.8-5.4%), 2.3% (95% CI: 1.6-3.2%) and 7.8%(95% CI: 5.7-10.3%); nephropathy: 7.1% (95% CI: 1.7-15.9%), 9.6% (95% CI: 0.8-26.4%) and 17.1% (95% CI: 1.0-46.9%); neuropathy: 2.1% (95% CI: 0.0-6.8%), 3.4% (95% CI: 0.0-11.6%) and 2.8% (95% CI: 0.0-12.8%). Multivariable meta-regression showed HbA1c ≥ 6.5% (OR: 4.05; 95% CI: 1.92-8.57%), age > 55 (OR: 3.23; 95% CI 1.81-5.77), and African-American race (OR: 10.73; 95% CI: 4.34-26.55), to be associated with higher retinopathy prevalence. Marked heterogeneity in prevalence estimates was found across all meta-analyses (Cochran's Q-statistic p < 0.0001).

CONCLUSIONS

The prevalence of nephropathy and moderate retinopathy was increased in subjects with HbA1c values ≥ 6.5% confirming the high specificity of this value for diagnosing T2DM; however, at HbA1c < 6.5% retinopathy increased at age > 55 years and, most strikingly, in African-Americans, suggesting there may be excess microvascular complication prevalence (particularly nephropathy) in individuals below the diabetes diagnostic threshold.

Glycosylated Hemoglobin as an Age-Specific Predictor and Risk Marker of Colorectal Adenomas in Non-Diabetic Adults

BACKGROUND

Diabetes is a risk factor for colorectal neoplasms. The association between the level of glycosylated hemoglobin (HbA1c) and the risk of colorectal adenomas (CRAs) in non-diabetic adults needs to be investigated.

METHODS

A cross-sectional study was performed on non-diabetic adults with normal HbA1c level who underwent colonoscopy between January 2010 and December 2016 during health check-ups in our hospital in China. The association between HbA1c level and CRAs was assessed by multiple logistic regression models stratified by age group (<40, ≥40 and <50, and ≥50 years old). The age group-specified thresholds for HbA1c on elevated risk of CRAs were estimated using the piecewise logistic regression.

RESULTS

Among the 2,764 subjects, 445 (16.1%) had CRA. The prevalence of CRA varied across the three age groups. A higher HbA1c level was found to be significantly associated with increased CRA risk in the 40-50 years group (odds ratio [OR]=1.70, 95% confidence interval [CI] 1.04-2.78, p=0.035) after adjusting for other related factors, while this association was borderline significant among the 50 years and older group (OR=1.57, 95% CI 0.97-2.54, p=0.067). Based on the piecewise logistic regression analysis results, the thresholds for HbA1c on elevated risk of CRA were 5.44% for the 40-50 years group and 4.81% for the 50 years and older group, respectively.

CONCLUSIONS

Higher levels of HbA1c, even within the normal range, were associated with elevated CRA risk among non-diabetic adults. The threshold effects of HbA1c on the risk of CRA varied across different age groups, and early screening colonoscopy might be needed for individuals in their 40s and with HbA1c levels ≥5.44%.

Increased Oxidative Stress Underlies Abnormal Pain Threshold in a Normoglycemic Japanese Population

Normal-high HbA1c levels are a risk factor for attenuated pain sensation in normoglycemic subjects. It is unclear, however, what mechanisms underlie the pathogenesis of attenuated pain sensation in such a population. We, therefore, explored the relationship between oxidative stress (OS) and pain sensation in a rural Japanese population. A population-based study of 894 individuals (average age 53.8 ± 0.5 years) and 55 subjects with impaired fasting glucose (IFG) were enrolled in this study. Individuals with diabetes were excluded. Relationships between pain threshold induced by intraepidermal electrical stimulation (PINT) and clinico-hematological parameters associated with OS were evaluated. Univariate linear regression analyses revealed age, BMI, HbA1c, the OS biomarker urine 8-hydroxy-2'-deoxyguanosine (8-OHdG), systolic blood pressure, and decreased Achilles tendon reflex on the PINT scores. Adjustments for age, gender, and multiple clinical measures confirmed a positive correlation between PINT scores and urine 8-OHdG (β = 0.09, p < 0.01). Urine 8-OHdG correlated positively with higher HbA1c levels and age in the normoglycemic population. Unlike in the normoglycemic population, both inflammation and OS were correlated with elevated PINT scores in IFG subjects. OS may be a major contributing factor to elevated PINT scores in a healthy Japanese population.

Correlates of autonomic nervous system function in a general population with special reference to HbA1c: The Nagahama study

AIMS

As the glucose tolerance of patients with diabetes worsens, autonomic nervous system (ANS) function decreases. Only a few studies, using plasma glucose, have reported on this relationship in large general populations that include people with wide range of glycemia. This study aimed to examine correlates of ANS function with special reference to HbA_1c which is more stable than plasma glucose among community residents.

METHODS

Spectral analysis was performed to assess heart rate variability (HRV) using 1-minute electrocardiogram RR interval data recordings from 7690 residents aged 35-79 years in Nagahama City, Japan. HRV parameters were log-transformed. Multiple regression analysis was performed using potential correlates.

RESULTS

lnLF decreased with age (regression coefficient, -0.025; P < 0.001), BMI (-0.010; P = 0.035), and HbA_1c (-0.068; P = 0.036). lnHF decreased with age (-0.029; P < 0.001), BMI (-0.032; P < 0.001), and HbA_1c (-0.173; P < 0.001). lnLF/HF increased with age (0.003; P = 0.002), BMI (0.023; P < 0.001), and HbA_1c (0.105; P < 0.001). Women showed lower lnLF and lnLF/HF than men. Sleep quality assessed by the Pittsburgh Sleep Quality Index, smoking and drinking had almost no relation.

CONCLUSIONS

Although the associations were weak, age, BMI and HbA_1c were inversely correlated with parasympathetic activity, while positively correlated with sympathetic activity among general residents.

HbA1c: The Glucose Management Indicator, Time in Range, and Standardization of Continuous Glucose Monitoring Reports in Clinical Practice

Continuous glucose monitoring (CGM) use is growing rapidly among people with diabetes and beginning to be standard of care for managing glucose levels in insulin therapy. With this increased use, there is a need to standardize CGM data. CGM standardization has been set forth by expert panels. The Glucose Management Indicator is a concept using the CGM-derived mean glucose to provide a value that can be understood similarly to hemoglobin A_1c. The times an individual spends in various glucose ranges is emerging as an important set of metrics. Metrics derived from patient CGM data are changing the way diabetes is managed.

Severity Indices for Obstructive Sleep Apnea Syndrome Reflecting Glycemic Control or Insulin Resistance

Objective We aimed to identify obstructive sleep apnea syndrome (OSAS) severity indices reflecting the anthropometric and metabolic characteristics of patients with OSAS. Methods A total of 76 patients with OSAS underwent nasal continuous positive airway pressure (nCPAP). We also investigated the effects of nCPAP on OSAS-associated muscle sympathetic nerve activity (MSNA), risk for cardiovascular diseases, and insulin secretion and sensitivity. Results Among the OSAS severity indices, HbA1c was significantly correlated with the apnea-hypopnea index, whereas HOMA-beta, HOMA-IR, and hepatic insulin resistance were significantly correlated with % SpO₂<90%, independent of age, gender, and body mass index (BMI). Burst incidence of MSNA was independently associated with only a 3% oxygen desaturation index. nCPAP therapy significantly lowered the OSAS severity indices and reduced the burst rate, burst incidence, and heart rate. Conclusion The OSAS severity indices reflecting apnea/hypopnea are associated with glycemic control, whereas those reflecting hypoxia, particularly % SpO₂<90%, are associated with hepatic insulin resistance independent of obesity. Both types of OSAS severity indices, especially the 3% oxygen desaturation index (reflecting intermittent hypoxia), are independently associated with MSNA, which is dramatically lowered with the use of nCPAP therapy. These findings may aid in interpreting each OSAS severity index and understanding the pathophysiology of OSAS in clinical settings.

HbA1c and retinal sensitivity in diabetics using microperimetry

PURPOSE

The purpose of this study was to determine the relationship between HbA1c values and retinal sensitivity at central 10° using the MP-1 microperimeter.

METHODS

A prospective study was carried out on 32 healthy subjects (control group) and 60 diabetic patients. The diabetic patients were divided into 2 groups. Group 1 comprised of 30 patients without diabetic retinopathy (DR) and group 2 had 30 patients with mild non-proliferative DR. A full-threshold microperimetry of the central 10° of retina (the macula) was performed on all subjects, utilizing 32 points with the MP-1. The relationship between light sensitivity and HbA1c value was calculated using linear regression analysis.

RESULTS

Total mean sensitivity at 10° for group 1 without DR, group 2 with mild NPDR and control group were 18.67±0.83, 17.98±1.42 and 19.45±0.34 (dB), respectively. There was a significant difference in total mean retinal sensitivity at 10° between the 3 groups (F(2,89)=18.14, p=0.001). A simple linear regression was calculated to predict HbA1c based on retinal sensitivity. A significant regression equation was found (F(1,90)=107.61, p=0.0001, with an R² of 0.545). The linear regression analysis revealed that there was a 0.64dB decline in mean retinal sensitivity within the central 10° diameter with an increase of 1mmHg of HbA1c.

CONCLUSION

Retinal sensitivity at the central 10° of the macula is affected by changes in HbA1c values.

Glycemic control is an important modifiable risk factor for uveitis in patients with diabetes: A retrospective cohort study establishing clinical risk and ophthalmic disease burden

AIM

To characterize the risk uveitis, scleritis or episcleritis in relation to diabetes, glycaemic control, and co-existence of retinopathy.

METHODS

Using the Royal College of General Practitioners Research and Surveillance Centre database, we established the prevalence of acute uveitis and scleritis or episcleritis over a six-year period among populations without(n = 889,856) and with diabetes(n = 48,584). We evaluated the impact of glycaemic control on disease risk. Regression modeling was used to identify associations, adjusting for clinical and demographic confounders.

RESULTS

Incidence of acute uveitis was higher among patients with diabetes; Type 1 OR:2.01 (95% CI 1.18-3.41; p = 0.009), and Type 2 OR:1.23 (1.05-1.44; p = 0.01). Glycaemic control was established as an important effect modifier for uveitis risk, whereby those with poorer control suffered higher disease burden. Results confirmed a dose-response relationship such that very poor glycaemic control OR:4.72 (2.58-8.65; p < 0.001), poor control OR:1.57 (1.05-2.33; p = 0.03) and moderate control OR:1.20 (0.86-1.68; p = 0.29) were predictive of uveitis. Similar results were observed when evaluating retinopathy staging: proliferative retinopathy OR:2.42 (1.25-4.69; p = 0.01). These results were not maintained for scleritis or episcleritis.

CONCLUSION

Acute uveitis is more common in patients with diabetes; at highest risk are those with type 1 disease with poor glycaemic control. Glycaemic improvements may prevent recurrence.

Hemoglobin A1c as a Predictor of Postoperative Infection Following Elective Forefoot Surgery

BACKGROUND

There remains little evidence to support a perioperative hemoglobin A_1c (HbA_1c) level that could serve as a threshold for a significantly increased risk of postoperative surgical site infection (SSI) following forefoot surgery.

METHODS

A national database was queried for patients who underwent elective forefoot surgery with diabetes. Patients with a perioperative HbA_1c level within 3 months of surgery were identified and stratified based on HbA_1c level in 0.5 mg/dL increments. The incidence of SSI was determined by either a diagnosis or procedure for SSI within 1 year and a receiver operating characteristic (ROC) curve and area under the curve (AUC) analysis was performed to determine an optimal threshold value of HbA_1c.

RESULTS

A total of 4630 patients who underwent forefoot surgery with diabetes with a perioperative HbA_1c were included. The rate of SSI ranged from 2.3% to 11.8%. The inflection point of the ROC curve corresponded to an HbA_1c level above 7.5 mg/dL ( P < .0001; 95% confidence interval [CI] = 0.58-0.67; AUC = 0.631; specificity = 75%; sensitivity = 46%). After multivariate analysis, patients with an HbA_1c level of 7.5 mg/dL or greater had a significantly higher risk for postoperative wound infection compared to patients below this threshold (OR = 1.92; 95% CI = 1.5-2.4; P < .0001).

CONCLUSIONS

The risk of postoperative SSI following forefoot surgery increased as the perioperative HbA_1c increased. ROC analysis determined that a perioperative HbA_1c above 7.5 mg/dL could serve as a threshold for a significantly increased risk of postoperative SSI following forefoot surgery.

LEVEL OF EVIDENCE

Level III, comparative series.

[Effect of laparoscopic sleeve gatrectomy on type 2 diabetes mellitus in obese patients with body mass index less than 40 kg/m2]

OBJECTIVE

To evaluate the effect of laparoscopic sleeve gastrectomy(LSG) on type 2 diabetes mellitus (T2DM) in patient with a body mass index(BMI) less than 40 kg/m².

METHODS

Twenty four obese patients with T2DM and BMI less than 40 kg/m² received LSG between 1 January 2011 and 1 September 2013 at the Department of General Surgery in Chinese PLA General Hospital. The clinical data and 3-year follow-up outcomes regarding weight loss and remission of diabetes were retrospectively analyzed.

RESULTS

There were 10 males and 14 females with a median age of 40.8(35 to 48) years. The preoperative body weight and BMI was(99.9±15.0) kg and (34.4±2.8) kg/m², respectively. The median duration of type 2 diabetes was 4.3(2 to 15) years. The preoperative fasting blood glucose and glycosylated hemoglobin(HbAlc) was (11.4±1.3) mmol/L and (8.7±0.8)%, respectively. All these patients were preoperatively diagnosed as T2DM by the multidisciplinary experts of the surgical treatment team for obesity and diabetes in our center. All these patients were eligible for surgical treatment through the screening and evaluation by the multidisciplinary joint outpatient service. All the procedures were successfully completed without conversion to laparotomy. There were no severe postoperative complications. The mean fasting blood glucose was (6.4±1.8) mmol/L, (6.1±1.7) mmol/L, (6.0±1.5) mmol/L, (5.9±1.4) mmol/L and (6.0±1.4) mmol/L, respectively, at 6, 9, 12, 24 and 36 months after operation. The mean HbA1c in the same observation intervals was (6.6±1.1)%, (6.2±1.2)%, (6.1±1.2)%, (6.0±1.3)% and (6.1±1.3)%, respectively. The body weight was (89.4±11.4) kg, (86.3±10.6) kg, (83.1±10.2) kg,(80.6±9.8) kg and (81.3±10.1) kg, respectively. The corresponding BMI was (30.8±1.6) kg/m², (29.8±1.5) kg/m², (28.7±1.5) kg/m², (27.8±1.8) kg/m² and (28.1±1.8) kg/m², respectively. The %EWL was (36.7±8.7)%, (47.6±12.5)%, (58.8±16.4)%, (67.2±20.3)% and (64.8±21.5)%, respectively. The overall remission rate of diabetes at 6, 9, 12, 24 and 36 months was 50.0%(12/24), 79.2%(19/24), 70.8%(17/24), 66.7%(16/24) and 62.5%(15/24), respectively. The complete remission rate was 33.3%(8/24), 50.0%(12/24), 54.2%(13/24), 45.8%(11/24) and 50.0%(12/24), respectively. For patients with a duration of T2DM shorter than 5 years, the overall remission rate at 9, 12 and 24 months after operation was 10/10, 9/10 and 9/10, respectively, significantly higher than that of patients with a duration of 11-15 years (2/6, 2/6 and 2/6, Fisher's exact tests, P=0.008, 0.036 and 0.036, respectively).

CONCLUSION

The present study confirms the efficacy of LSG in the treatment of T2DM patients with a BMI less than 40 kg/m².

[Nutrition management in obese patients with type 2 diabetes mellitus after laparoscopic sleeve gastrectomy]

OBJECTIVE

To explore the value of nutrition management in obese patients with type 2 diabetes mellitus(T2DM) after laparoscopic sleeve gastrectomy(LSG).

METHODS

Clinical data of 22 obese T2DM patients undergoing LSG from March 2013 to July 2015 in Fudan University Pudong Medical Center were collected. All the patients strictly followed the specialized instruction by nutritionists: diabetic and low calorie diet 3347.2 to 5020.8 kJ (800 to 1200 kcal) per day before the operation; low calorie liquid diet 2510.4 kJ(600 kcal) per day before operation for promoting gastric emptying; fasting diet before postoperative ventilation; clear liquid diet 1673.6 to 2510.4 kJ (400 to 600 kcal) per day after postoperative ventilation (liquid intake >2000 ml); low fat liquid diet 2928.8 to 3765.6 kJ (700 to 900 kcal) per day (protein 60 g per day at least, 2000 ml liquid) 2 weeks after the operation; semi-liquid diet 1 month after operation and gradually normal diet. All the 22 patients were followed up at 1 week, 1, 3, 6 months after operation on time. Changes of body weight, waist circumference, hip circumference, body mass index(BMI), blood glucose indexes induding fasting blood glucose(FBG), 2-hour postparandial blood glucose(PBG), fasting C-peptide, 2-hour postprandial C-peptide, fasting serum inculin(FINS), 2-hour postprandial inculin(INS), HbAlc, blood pressure and blood lipid indexes were observed and analyzed before and 1 week, 1, 3, 6 months after operation.

RESULTS

The average age of 22 patients (10 men and 12 women) was 38.6 years (18 to 66 years). The duration of diabetes varied from 1 month to 15 years. Comorbidity included 12 patients of high blood pressure, 14 of fatty liver, 1 of coronary heart disease, 1 of gout, 1 of chronic thyroiditis and 1 of menstrual disorder. LSG was performed successfully in all the patients and no severe complications and transference to laparotomy occurred. As compared to pre-operation, at 6 months after operation, the average body weight decreased from (103.9±20.2) kg to (80.9±12.6) kg (t=6.294, P=0.000), waist circumference from (118.6±13.8) cm to (96.4±8.0) cm (t=6.331, P=0.000), hip circumference from (116.9±12.6) cm to (104.0±7.7) cm (t=3.854, P=0.000), BMI from (36.2±5.9) kg/m² to (27.9±3.5) kg/m² (t=5.630, P=0.000), showing a decreasing trend over time. There was no underweight patient after 6 months follow-up. As compared to pre-operation, at 6 months after operation, the average FBG reduced from (7.4±1.4) mmol/L to (6.0±0.9) mmol/L (t=3.172, P=0.003), 2 h PBG from (14.1±4.9) mmol/L to (7.5±2.2) mmol/L (t=7.026, P=0.000), FINS from (160.0±71.9) mIU/L to (43.8±20.8) mIU/L (t=7.259, P=0.000), 2-hour postprandial INS from (437.6±261.4) mIU/L to (140.5±104.6) mIU/L (t=5.858, P=0.000), fasting C-peptide from (1.1±0.6) μg/L to (0.7±0.3) μg/L (t=3.560, P=0.000), 2-hour postprandial C-peptide from (2.5±0.9) μg/L to (1.5±0.7) μg/L (t=3.865, P=0.000), HbAlc from (8.0±1.6)% to (5.9±0.6)% (t=5.953, P=0.000), showing a decreasing trend over time except FBG, 2h postprandial C-peptide and HbAlc(all P<0.05). FBG and 2-hour PBG of 16 patients returned to normal 3 months after the operation. Blood pressure and trigly ceride decreased obviously 6 months after operation compared to pre-operation with significant difference(P<0.05). At 6 months after operation, blood pressure of 8 comorbidity patients with high blood pressure became normal (8/12, 66.7%) and of 4 patients improved(4/12, 33.3%); B ultrasound examination revealed normal in 11 comorbidity patients with fatty liver(11/14,78.6%) and improvement in 3 patients (3/14,15.4%). Blood uric acid of the gout patient and the menstruation of the menstrual disorder patient returned to normal 3 months and 1 month after the operation respectively.

CONCLUSION

As for obese patients with T2DM undergoing LSG, reasonable nutrition management is helpful to decrease body weight, and to obtain an ideal improvement of blood glucose and blood lipid levels.

[Effect of laparoscopic sleeve gastrectomy on sex hormone in male severe obesity]

OBJECTIVE

To investigate the effect of laparoscopic sleeve gastrectomy(LSG) on sex hormone in male patients with severe obesity.

METHODS

Retrospective analysis was performed in 31 male patient with severe obese [body mass index(BMI) ≥28 kg/m², obesity group] who underwent LSG in Shanghai Tenth People's Hospital of Tongji University from December 2012 to May 2016. The anthropometric parameters(weight, BMI, waist circumference, hip circumference, waist-hip ratio, body fat percentage), glucose metabolic indices [fasting plasma glucose(FPG), fasting insulin (FINS), glycosylated hemoglobin (HbA1c), homeostasis model assessment-insulin resistance index(HOMA-IR)], and sex hormone parameters [estradiol(E2), total testosterone (TT), follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] were collected preoperatively and 1, 3, 6 months postoperatively. In addition, 31 healthy male volunteers with normal BMI were consecutively recruited in this study as control group. The above-mentioned parameters were also determined in control group. Changes of these variables before and after surgery were analyzed. Pearson method was used to analyze the correlation of TT with anthropometric parameters and glucose metabolic indices before and after surgery.

RESULTS

The average age of patients in obesity and control group was (32.9±9.7) (18 to 56) years and (30.7±8.9) (18 to 49) years. Compared to the control group, obesity group had significantly higher anthropometric parameters and glucose metabolic indices before surgery (all P<0.05). In obesity group, the anthropometric and glucose metabolic indices significantly decreased at 1 to 6 months after surgery compared to those before surgery (all P<0.05). At 1 month after surgery, the anthropometric parameters and glucose metabolic indices in obesity group were significantly higher than those in control group (all P<0.05). At 3, and 6 months after surgery, there were no significant differences in glucose metabolic indices between obesity and control group (all P>0.05), while the anthropometric parameters in obesity group were still significantly higher than those in control group(all P<0.05). The sex hormone parameters in control and obesity group before surgery were as follows: E2: (100.2±23.5) pmol/L and (129.2±81.9) pmol/L; TT: (18.0±4.9) nmol/L and (8.4±4.5) nmol/L; FSH: (4.5±3.1) IU/L and (4.3±2.5) IU/L; LH: (4.4±1.7) IU/L and (5.3±2.6) IU/L. Compared to control group, the TT level of obese patients before surgery significantly decreased(P=0.000), while no significant differences were observed in the levels of E2, FSH, and LH(all P>0.05). The TT levels were significantly increased at 1, 3, 6 months after surgery[(13.1±7.0), (13.6±5.7), (21.0±19.3) nmol/L, respectively, all P<0.05] and the E2 level was significantly decreased at 6 months after surgery [(91.4±44.9) pmol/L, P<0.05], while no significant differences were observed at 1 and 3 months after surgery (all P>0.05). Furthermore, the FSH and LH levels did not exhibit significant change at 1, 3, and 6 months after surgery compared to those before surgery (all P>0.05). At 1 month after surgery, no significant correlations were examined in the change value of TT levels (▹TT) with the changes of BMI(▹BMI), FPG(▹FPG), FINS(▹FINS), HOMA-IR(▹HOMA-IR), and E2(▹E2) (all P>0.05). At 3 months after surgery, ▹TT was negatively correlated with ▹BMI (r=-0.441, P=0.015), ▹FINS (r=-0.375, P=0.041), and ▹HOMA-IR(r=-0.397, P=0.030), but not correlated with ▹FPG and ▹E2 (all P>0.05). At 6 months after surgery, ▹TT was negatively correlated with ▹BMI(r=-0.510, P=0.018) and ▹HOMA-IR (r=-0.435, P=0.049), but not correlated with ▹FPG, ▹FINS and ▹E2 (all P>0.05).

CONCLUSIONS

Male severe obese patients are accompanied with abnormal sex hormone levels. LSG has a significant effect on weight loss and blood glucose improvement, and may ameliorate the sex hormone unbalance by improving the insulin resistance in men with severe obesity.

Physical activity patterns and gestational diabetes outcomes - The wings project

OBJECTIVE

To compare physical activity (PA) patterns in pregnant woman with and without gestational diabetes (GDM) and to assess the effects of an exercise intervention on change in PA patterns, blood glucose levels and pregnancy outcomes in GDM women.

METHODS

For the first objective, PA patterns were studied in 795 pregnant women with and without GDM. For the second objective, the Women in India with Gestational Diabetes Strategy-Model of Care (WINGS-MOC) intervention were evaluated in 151 women out of 189 with GDM. PA was assessed using a validated questionnaire and a pedometer. Changes in PA patterns, glycemic parameters and neonatal outcomes were evaluated.

RESULTS

Overall, only 10% of pregnant women performed recommended levels of PA. Women with GDM were significantly more sedentary compared to those without GDM (86.2 vs. 61.2%, p<0.001). After the MOC was implemented in women with GDM, there was a significant improvement in PA and a decrease in sedentary behaviour amongst women (before MOC, moderate activity: 15.2%, sedentary: 84.8% vs. after MOC-moderate: 26.5%, sedentary: 73.5%; p<0.001), and an increase in their daily step count from 2206/day to 2476/day (p<0.001). Fasting 1 and 2-h postprandial glucose values significantly decreased (p<0.001 for all). Sedentary behaviour was associated with a fourfold higher risk (p=0.02), and recreational walking with 70% decreased risk, of adverse neonatal outcomes (p=0.04) after adjusting for potential confounders.

CONCLUSIONS

PA levels are inadequate amongst this group of pregnant women studied i.e. those with and without GDM. However, a low-cost, culturally appropriate MOC can bring about significant improvements in PA in women with GDM. These changes are associated with improved glycemic control and reduction in adverse neonatal outcomes.

Increased Intraocular Pressure and Hyperglycemic Level in Diabetic Patients

Purpose

To determine whether hyperglycemic levels as determined from high hemoglobin A1c (HbA1c) levels influence intraocular pressure (IOP) in patients with non-proliferative diabetic retinopathy (NPDR).

Methods

A retrospective chart review was performed on subjects with a diagnosis of NPDR and a corresponding HbA1c level measured within 90 days before or after an IOP measurement over a two-year period. Exclusion criteria included a diagnosis of glaucoma or treatment with IOP lowering medications or oral or topical steroids.

Results

Using 14.5mmHg as a baseline mean value for IOP, 42 subjects had an IOP < 14.5mmHg and mean HbA1c of 8.1±1.1, while 72 subjects had an IOP ≥ 14.5mmHg and a mean HbA1c of 9.0±2.1. Although there was an overlap in the confidence intervals, a significant difference (P = 0.01) in the mean HbA1c level was observed in regression analysis between the two groups. Importantly, diabetic subjects with elevated HbA1c levels rarely (<1%) exhibited reduced IOP levels.

Conclusions

Diabetic subjects with elevated HbA1c levels exhibited significantly higher IOPs compared to those with lower HbA1c levels. Findings from this study indicate an association between hyperglycemia and elevated IOP and that poor glycemic control may contribute to increased IOP levels in long-term diabetic patients.

The relationship between glycated hemoglobin and complexity of coronary artery lesions among older patients with diabetes mellitus

Objectives

Glycated hemoglobin (HbA1c) is associated with an increased risk of cardiovascular disease. The aim of this study was to examine the relationship between HbA1c levels and the complexity of coronary artery lesions among the older patients with diabetes mellitus (DM).

Methods

This retrospective study enrolled a total of 3805 consecutive type 2 DM patients aged 60 years and older who underwent their first elective coronary angiography and had their HbA1c levels measured at the Chinese PLA General Hospital between December 2005 and December 2012.The complexity of the coronary artery lesions was evaluated using the Syntax score, and the subjects were divided into three groups according to their HbA1c levels. Logistic regression and Pearson correlation were used to analyze the association between the measured HbA1c levels and Syntax score.

Results

The mean age was 72.3±10.6 years. The higher HbA1c levels were significantly associated with higher Syntax score (p<0.001). The unadjusted correlation coefficient of HbA1c levels and the Syntax score was 0. 371 (p<0.001). In addition, the higher HbA1c categories were able to independently predict patients with intermediate or high Syntax score (Syntax score ≥23) after adjustment for age, sex, hypertension, smoking, dyslipidemia and creatinine levels in the logistic regression analysis.

Conclusion

HbA1c is significantly associated with the complexity of coronary lesions among older patients with DM. A higher HbA1c value is an independent predictor of the prevalence of complex coronary lesions. Further prospective multi-centre studies are needed to confirm this finding.

Using hemoglobin A1c to derive mean blood glucose in peritoneal dialysis patients

BACKGROUND

Although hemoglobin A1c (HbA1c) has been widely used as a clinical assessment tool for outcome analyses related to glycemic control, the relationship between HbA1c and average blood glucose (BG) specific to peritoneal dialysis (PD) patients with diabetes has not been characterized. We sought to develop HbA1c-BG equation models for PD patients.

METHODS

We examined associations between HbA1c and random serum BG values over time in a contemporary 5-year (2001-2006) cohort of DaVita PD patients with diabetes. We identified 850 patients (mean age: 58 ± 13 years, 56% male) with 4,566 paired measurements of HbA1c and BG. The bootstrapping method was used to estimate average BG and corresponding HbA1c.

RESULTS

Linear regression analyses yielded the following HbA1c-BG equations: (1) BG (mg/dl) = 24.1 + 28.6 × HbA1c - 12.2 × albumin [adjusted R(2) (R(2)adj = 0.454)], (2) BG = 55.3 + 28.8 × HbA1c - 10.2 × albumin - 3.3 × Hb (R(2)adj = 0.457), and (3) BG = 69.5 + 28.7 × HbA1c - 10.1 × albumin - 3.7 × Hb - 0.1 × age + race/ethnicity (-10.1 African Americans, -5.4 other race/ethnicities; R(2)adj = 0.457). All models showed greater explanatory power of BG variation than previously established HbA1c-BG equation models defined within non-PD cohorts [R(2)adj = 0.446 for both the Diabetes Control and Complications Trial (DCCT) and the A1c-Derived Average Glucose (ADAG) equations].

CONCLUSIONS

The association between HbA1c and BG in PD patients is different than that of patients with normal kidney function. Our analysis suggests that equations incorporating serum albumin and/or Hb values better estimate the HbA1c-BG relationship in PD patients compared to equations using HbA1c alone.

Slow post meal walking reduces the blood glucose response: an exploratory study in female Pakistani immigrants

Postprandial physical activity may blunt the blood glucose response. In diabetes prone female immigrants only slow walking is regularly performed raising the question of whether also this type of physical activity can attenuate their post meal blood glucose elevation. Using a cross over design, 11 female Pakistani immigrants living in Oslo were recruited to participate in three experiments where their blood glucose concentration was measured every 15 min for 2 h after intake of a high glycemic food, either while resting after the meal or doing very light post meal walking of two durations. Postprandial blood glucose peak value and incremental area under the 2 h blood glucose curve decreased with increasing duration of slow post meal walking. Also the blood pressure was lowered. Post meal walking can strongly attenuate the glycemic response to carbohydrates and reduce blood pressure in a high risk group of immigrants.

[Mechanism of the biological impact of weak electromagnetic fields and in vitro effects of degassing of blood]

The physical validity of the mechanism proposed by the author is discussed. According to the theory a prolonged exposure to weak electromagnetic fields leads to an enlargement of the micro-bubbles and degassing of bioliquid. Degassing alters the physical and chemical properties of bioliquid that affect some medical and biological indicators. The following changes in some blood parameters during degassing in vitro were analyzed: a decrease in the glucose concentration, an abnormal activation of blood clotting, an increase in the rate of blood cell aggregation, a decrease in the effectiveness of aspirin as an inhibitor of platelet aggregation and the slowing of indirect anticoagulants. All of this evidences a possible correlation between the increasing electromagnetic pollution and the risk of cardiovascular disease.

An analysis of early insulin glargine added to metformin with or without sulfonylurea: impact on glycaemic control and hypoglycaemia

AIM

To evaluate the benefits of initiating insulin at an earlier versus later treatment stage, and regimens with/without sulfonylurea (SU).

METHODS

Pooled analysis of 11 prospective randomized clinical trials, including 2171 adults with uncontrolled type 2 diabetes initiating insulin glargine following a specific titration algorithm. Clinical outcomes were glycated haemoglobin A1c (HbA1c) reduction, per cent achieving HbA1c ≤ 7.0%, weight gain and hypoglycaemic events. Statistical analysis compared outcomes 24 weeks after basal insulin initiation in patients previously uncontrolled on 0/1 oral antidiabetic drug (OAD) versus 2 OADs, and in patients taking metformin (MET) or SU alone or in combination at baseline. A meta-analysis was also conducted.

RESULTS

For the pooled analysis, patients on 0/1 OAD and those on MET monotherapy at baseline had the largest 24-week reductions in HbA1c following the addition of insulin glargine (∼0.44 U/kg). Of patients failing MET/SU monotherapy and MET + SU in combination, 68.1, 50.4 and 56.4% achieved HbA1c ≤ 7.0%, respectively (p = 0.0006). Weight gain was lowest when basal insulin was added to MET. Patients on 0/1 OAD at baseline had significantly less symptomatic hypoglycaemia when basal insulin was added than those on 2 OADs (p = 0.0007). Despite higher insulin doses, those taking MET alone had less hypoglycaemia than those taking SU or MET + SU. Results were confirmed in the meta-analysis.

CONCLUSION

Adding insulin glargine to MET monotherapy early in treatment may provide efficacy/safety benefits over regimens including SU. This may reflect treatment earlier in the disease and supports the inclusion of insulin as a second step in the American Diabetes Association/European Association for the Study of Diabetes treatment algorithm.

Race-ethnicity as an effect modifier of the association between HbAlc and mortality in U.S. adults without diagnosed diabetes

OBJECTIVE

HbAlc is increasingly appreciated as a risk factor for all-cause and cardiovascular disease (CVD) mortality in the non-diabetic population. In this study, we investigated the association between HbAlc and mortality with a particular focus on the impact of race-ethnicity. Design Cohort study.

METHODS

We analyzed the association between HbAlc and all-cause and CVD mortality in 12 698 non-diabetic adults 20 years or older from the Third National Health and Nutrition Examination Survey using separate models for people of different race-ethnicity.

RESULTS

In our stratified analyses, higher non-diabetic HbAlc levels were associated with all-cause and CVD mortality in non-Hispanic whites only. In this group, compared with HbAlc values of 5.0-<5.35%, the multivariable-adjusted estimated hazard ratios (est. HR) with 95% confidence interval (CI) for all-cause mortality were 1.21 (0.92, 1.58), 1.22 (1.03, 1.45), 1.29 (1.14, 1.47), and 1.4 (1.02, 1.87) for HbAlc levels of <5.0, 5.35-<5.7, 5.7-<6.5, and 6.5% or greater respectively. The association did not reach significance in Mexican-Americans (est. HR (95% CI): 1.77 (1.08, 2.91), 0.81 (0.56, 1.19), 1.16 (0.86, 1.57), and 1.4 (0.83, 2.36)). No association was observed in non-Hispanic blacks: 1.13 (0.91, 1.39), 0.81 (0.61, 1.08), 0.84 (0.69, 1.03), and 0.94 (0.67, 1.33). Results were similar for CVD mortality.

CONCLUSIONS

Our data suggest limitations of HbAlc as a risk factor for all-cause and cardiovascular mortality across race-ethnic populations.

The associations of apolipoprotein E and angiotensin-converting enzyme polymorphisms and cognitive function in Type 1 diabetes based on an 18-year follow-up of the DCCT cohort

AIMS

Specific polymorphisms of the apolipoprotein E (APOE) and angiotensin-converting enzyme (ACE) genes appear to increase risk for Alzheimer's disease and cognitive dysfunction in the general population, yet little research has examined whether genetic factors influence risk of cognitive dysfunction in patients with Type 1 diabetes. The long-term follow-up of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) population provides an opportunity to examine if specific genetic variations in APOE and ACE alter risk for cognitive decline.

METHODS

Neurocognitive function in Type 1 diabetic subjects from the DCCT/EDIC study was assessed at DCCT entry and re-assessed approximately 18 years later, using a comprehensive cognitive test battery. Glycated haemoglobin (HbA(1c)) and the frequency of severe hypoglycaemic events leading to coma or seizures were measured over the 18-year follow-up. We determined whether the APO epsilon4 and ACE intron 16 indel genotypes were associated with baseline cognitive function and with change over time, and whether they conferred added risk in those subjects experiencing severe hypoglycaemic events or greater glycaemic exposure.

RESULTS

None of the APOE or ACE polymorphisms were associated with either baseline cognitive performance or change in cognition over the 18-year follow-up. Moreover, none of the genotype variations altered the risk of cognitive dysfunction in those subjects with severe hypoglycaemic episodes or high HbA(1c).

CONCLUSIONS

In this sample of young and middle-aged adults with Type 1 diabetes, APO epsilon4 and ACE D alleles do not appear to increase risk of cognitive dysfunction.

HbA1c: how do we measure it and what does it mean?

PURPOSE OF REVIEW

Description of recent developments in the standardization of HbA1c measurement and interpretation of HbA1c results.

RECENT FINDINGS

HbA1c is extensively used in the management of patients with diabetes. The two major schemes to standardize HbA1c produce values that differ substantially. A prospective, multinational study revealed a linear correlation between HbA1c and average blood glucose. Some, but not all, assay methods are able to accurately measure HbA1c in individuals with common hemoglobin variants.

SUMMARY

Progress in standardization of methods for HbA1c measurement has significantly reduced variation among different methods. The improved accuracy could allow HbA1c to be used for screening and diagnosis of diabetes. A consensus document recommends that HbA1c be reported in both NGSP (%) and IFCC (mmol/mol) units. HbA1c results can be translated into estimated average glucose (eAG), which could be reported in addition to HbA1c.

Significant correlation of glycated albumin, but not glycated haemoglobin, with arterial stiffening in haemodialysis patients with type 2 diabetes

OBJECTIVE

We recently reported that glycated albumin (GA) is a better indicator of glycaemic control compared with glycated haemoglobin (HbA1c) in haemodialysis (HD) patients with type 2 diabetes. As poor glycaemic control is considered an independent risk factor for atherosclerosis in diabetes, the relationship between GA, HbA1c and arterial stiffening was examined in HD patients with type 2 diabetes.

PATIENTS AND METHODS

The present study comprised 134 HD patients with type 2 diabetes, and 158 patients without diabetes. Brachial-ankle pulse wave velocity (baPWV) was measured in all patients using a waveform analyser.

RESULTS

The mean plasma glucose (PG), GA and HbA1c levels were 7.49 +/- 2.28 mmol/l, 20.8 +/- 5.57% and 5.62 +/- 1.26%, respectively, in HD patients with diabetes (n = 134), which were significantly greater than the respective values of 5.77 +/- 1.89 mmol/l, 15.6 +/- 2.34% and 4.98 +/- 0.80% in those without diabetes (n = 158) (P < 0.0001). BaPWV was 21.69 +/- 6.90 m/s in HD patients with diabetes, which was significantly greater than the value of 18.74 +/- 4.89 m/s in those without diabetes (P < 0.0001). When the analysis was performed in a combined population of those patients with and without diabetes, the mean PG (r = 0.155, P < 0.05) and GA (r = 0.117, P < 0.05), but not HbA1c (r = 0.092, P = 0.125), exhibited significant correlations with baPWV. Multivariate regression analysis, which included age, gender, mean blood pressure, and serum levels of albumin, creatinine and LDL cholesterol, to evaluate the independent association of each marker for glycaemic control with baPWV values in HD patients demonstrated that GA, but not HbA1c or PG, was an independent factor that was significantly associated in a positive manner with baPWV in HD patients.

CONCLUSION

It was suggested that poor glycaemic control, as reflected by increased GA values, might be associated with increased arterial stiffening in HD patients.

[Glycated haemoglobin--is it its exclusive position in diabetology under threat?]

Hyperglycaemia is the common characteristic for diabetes patients. Prolonged hyperglycaemia due to absolute or relative lack of insulin is the cause of microangiopathy. Glucose reacts with both blood vessel wall proteins and plasmatic proteins and erythrocyte haemoglobin. This characteristic of glucose is used to monitor the level of diabetes compensation. The level of glycated haemoglobin reflects glycaemia for the last 2 to 3 months. It began to be used in diabetology in the 1980's. This outline paper deals with some of the pitfalls with which glycated haemoglobin has been recently associated. The first part is dedicated to factors influencing haemoglobin glycation. The second, methodological part focuses on factors influencing its assessment and interpretation. The third part concentrates on the options for the substitution ofglycated haemoglobin by other diabetes compensation markers.

Effects of aerobic exercise on lipids and lipoproteins in adults with type 2 diabetes: a meta-analysis of randomized-controlled trials

OBJECTIVE

To conduct a meta-analysis of randomized-controlled trials in order to examine the effects of 8 weeks or more of aerobic exercise on lipids and lipoproteins in adults with Type 2 diabetes.

METHODS

Studies were included if total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), ratio of TC to HDL-C (TC/HDL-C), triglycerides (TG), or all of the above, were assessed. A secondary outcome was glycosylated haemoglobin (HbA1).

RESULTS

Seven studies representing 220 men and women (112 exercise, 108 control) were available for pooling. Using a random-effects model, a statistically significant reduction of about 5% was found for LDL-C, whereas no statistically significant improvements were found for TC, HDL-C, TC/HDL-C or TG. A trend for a statistically significant reduction in HbA1 was also found.

CONCLUSIONS

Although our overall results suggest that aerobic exercise lowers LDL-C in adults with Type 2 diabetes, additional randomized-controlled trials are needed on this topic.

Viscosity, hemostasis and inflammation in atherosclerotic heart diseases

BACKGROUND

In atherosclerotic diseases vascular reserve is impaired and pressure gradient is decreased, therefore the reduced blood fluidity can lead to tissue ischemia more rapidly. In previous investigations we demonstrated the deterioration of plasma and whole blood viscosities in patients with acute ischemic coronary syndromes, chronic coronary artery disease, and percutaneous transluminal coronary angioplasty.

METHODS

Hemorheological variables (plasma and whole blood viscosities, hematocrit, red blood cell aggregation), hemostaseological parameters (plasma fibrinogen and von Willebrand factor (vWf)), and platelet aggregation were detected in more recent studies in cardio- and cerebrovascular diseases, and diabetes mellitus. Common risk factors (lipid profile, smoking, glucose level, previous diseases) and medication were also recorded.

RESULTS

High portion of vascular patients were demonstrated to have poor ex vivo platelet inhibition. Effective antiplatelet treatment detected by aggregometry was related to lower plasma fibrinogen concentration and red blood cell aggregation and was also associated with less recurrent vascular events during the follow-up (p < 0.001). Beside the impaired hemorheological characteristics, the diabetic patients showed elevated vWf activity, which turned to correlate with hemoglobin A1c concentration (p < 0.01) rather than the fasting glucose.

SUMMARY

Our studies indicate the active role and interaction of hemorheological and hemostaseological factors in atherosclerotic heart diseases.

Combined effects of hemoglobin A1c and C-reactive protein on the progression of subclinical carotid atherosclerosis: the INVADE study

BACKGROUND AND PURPOSE

Glycohemoglobin (hemoglobin A1c [HbA1c]) and high-sensitivity C-reactive protein (hsCRP) are risk indicators for atherosclerosis. Limited information exists regarding the combined effects of inflammation and hyperglycemia. We investigated the joint effects of both parameters on early carotid atherosclerosis progression and major vascular events in diabetic and nondiabetic subjects.

METHODS

We analyzed the data of INVADE (Intervention Project on Cerebrovascular Diseases and Dementia in the Community of Ebersberg, Bavaria), a prospective, population-based study conducted in 3534 subjects (mean age, 69 years). In addition to common risk factors, measurements of carotid intima-media thickness (IMT), hsCRP, and HbA1c were performed at baseline and after 2 years of follow-up.

RESULTS

For the entire population, IMT progression was significantly related to HbA1c (P=0.003) but not to hsCRP (P=0.06) after risk factor adjustment. The interaction hsCRPxHbA1c was highly significant (P=0.001), and the most pronounced IMT progression was seen in subjects with both parameters in the fourth quartiles compared with subjects with both parameters in the first quartiles (0.028 [0.025, 0.031] versus 0.012 mm/year [0.007, 0.019]; P=0.0013). We observed a significant joint effect of HbA1c and hsCRP on IMT progression in the diabetic (n=882) as well as the nondiabetic subgroup (n=2652). Subjects with HbA1c and hsCRP in the upper 2 quartiles had an increased risk for new vascular events (adjusted hazard ratio in diabetics: 4.3 [1.8, 7.3]; P=0.001; nondiabetics: 2.9 [1.6, 4.7]; P=0.001).

CONCLUSIONS

The combination of hyperglycemia and inflammation is associated with an advanced early carotid atherosclerosis progression and an increased risk of new vascular events in diabetic as well as nondiabetic subjects.

Impact of changes in HbA1c, lipids and blood pressure on long-term outcomes in type 2 diabetes patients: an analysis using the CORE Diabetes Model

OBJECTIVES

Various factors influence the risk of complications in type 2 diabetes patients. The isolated impact of single risk factors on long-term outcomes is unclear. The aim of this study was to calculate the projected effects on life expectancy (LE), quality-adjusted LE (QALE) and total costs of complications (TC) of 10% improvements in baseline levels of either total cholesterol (T-CHOL), high-density lipoprotein cholesterol (HDL), systolic blood pressure (SBP), glycosylated haemoglobin (HbA1c), and all four parameters combined.

METHODS

A cohort of newly diagnosed patients (baseline age 52 years, HbA1c 9.1%, SBP 137 mmHg, T-CHOL 212 mg/dL, and HDL 39 mg/dL) was defined. The CORE Diabetes Model was used to simulate LE, QALE and TC (US third-party payer perspective discounted at 3% annually) over patients' lifetimes, assuming no change in risk factors, an isolated 10% improvement in each parameter, or a 10% improvement in all parameters simultaneously.

RESULTS

Improved HbA1c led to increases in LE and QALE of 1.00 and 0.81 years respectively, and decreased TC of (US) 10,800 dollars/patient. Improved SBP led to improvements in LE and QALE of 0.67 and 0.55 years respectively and decreased TC of 7,049 dollars. Decreased T-CHOL led to improvements in LE and QALE of 0.29 and 0.20 years, respectively, and increased TC of 1,923 dollars. Increased HDL led to improvements in LE and QALE of 0.28 and 0.18 years respectively, and increased TC of 2,162 dollars. Simultaneous improvements in all parameters led to projected improvements in LE and QALE of 2.17 and 1.72 years respectively, and decreased TC of 14,533 dollars.

CONCLUSIONS

Combined improvements in HbA1c, lipid levels and SBP produced the greatest benefits in terms of LE, QALE and TC. A 10% improvement in HbA1c had the greatest impact on these three outcomes.

Metformin attenuates progression of carotid arterial wall thickness in patients with type 2 diabetes

To investigate the anti-atherogenic effect of metformin, we prospectively evaluated the effect of metformin treatment on common carotid intima-media thickness (CCA-IMT) in patients with type 2 diabetes. A 2-year open prospective study was performed. Thirty-six patients were treated with metformin (500-750 mg per day). CCA-IMT was measured after 1- and 2-year treatment. Changes in CCA-IMT were compared with control patients. After 2-year metformin therapy, the progression of CCA-IMT was significantly less than 56 control patients (0.02+/-0.08 mm versus 0.07+/-0.08 mm, P<0.01). Metformin therapy did not alter body weight, blood pressure, HbA1c, and serum lipids relative to the control. Thus, metformin attenuates the progression of CCA-IMT. This anti-atherogenic effect is not mediated through changes in classical cardiovascular risk factors.

Mean platelet volume in Type 2 diabetic patients

BACKGROUND

Altered platelet morphology and function have been reported in patients with diabetes mellitus. They are likely to be associated with the pathological processes and increased risk of vascular disease seen in these patients. We aimed to determine the mean platelet volume (MPV) in diabetics compared to nondiabetics, to see if there is a difference in MPV between diabetics with and without macro- and microvascular complications, and to determine the correlation between MPV and fasting blood glucose, glycosylated hemoglobin (HbA(1)c), patient age, and duration of diabetes, respectively.

METHODS

We measured MPV in 145 consecutive Type 2 diabetic patients and 100 nondiabetic control subjects without known coronary artery disease who had complete blood count on venous blood sample taken into tripotassium EDTA, using a Roche Minos cell counter and automatic blood counter (CELL-DYN 3500). The blood glucose level was measured by glucose oxidase method and HbA1c by calorimetrical method in the autoanalyser. Statistical evaluation was performed by SPSS for Windows statistics programme using multivariate logistical regression analysis, Student's t, and Pearson correlation tests.

RESULTS

MPV was significantly higher and the mean platelet counts were significantly lower in diabetics compared to age- and sex-matched nondiabetic healthy controls [10.62+/-1.71 fl vs. 9.15+/-0.86 fl (P=.00), 260.38+/-68.65 x 10(9)/l vs. 292.33+/-79.19 x 10(9)/l (P=.001)], respectively.

CONCLUSIONS

Our results show significantly higher MPV in diabetic patients than in the nondiabetic controls. This suggests that platelets may play a role in the micro- and macrovascular complications of diabetic patients.

Oral therapies for diabetic hyperglycemia

Many classes of oral antihyperglycemic agents are available for the treatment of type 2 diabetic patients. These classes improve glucose metabolism by different mechanisms, and their effects are additive. Therapy with lifestyle modification and a single oral antihyperglycemic agent infrequently achieves target glycemic goals, and, if it does, the effect is usually not sustained. A more rational approach would seem to be therapy with combinations of drugs with different mechanisms of action. Initial therapy might be with submaximal concentrations of two drugs. As the diabetic abnormalities progress, maximal concentrations of the drugs and addition of other classes of oral agents or insulin may be needed to maintain the target glycemic goal. In choosing combinations of oral antihyperglycemic agents, their effects on the components treatment of type 2 diabetic patients. These classes improve glucose considered, as must the specific effects of the agents on glucose metabolism.

Highly glycated oxyhaemoglobin impairs nitric oxide relaxations in human mesenteric microvessels

AIMS/HYPOTHESIS

It has been recently shown that glycated human haemoglobin induces endothelial dysfunction in rat vessels by generating superoxide anions that interfere with nitric oxide mediated responses. Our study analysed the effect of glycated human haemoglobin on the endothelium-dependent relaxations of human vessels.

METHODS

Omental microvessels were obtained from patients (without diabetes, hypertension or vascular disease) during surgery and mounted in a small vessel myograph to study their vasoactive responses (vessels from 3-7 patients for each set of experiments).

RESULTS

Cumulative vasodilatory responses to bradykinin (10 nmol/l to 3 mumol/l) were induced in vessels precontracted with 35-50 mmol/l potassium chloride. Addition of 100 mumol/l NG-nitro-L-arginine methyl ester reduced the relaxation evoked by bradykinin, but preincubation with both NG-nitro-L-arginine methyl ester and 10 mumol/l indomethacin was needed to abolish it. Bradykinin-induced responses were inhibited by 1 mumol/l non-glycated oxyhaemoglobin whereas no effect was obtained with 10 nmol/l oxyhaemoglobin. At these low concentrations (10 nmol/l), glycated human oxyhaemoglobin caused an impairment of bradykinin-induced relaxation when the percentage of glycation was 10% or higher. This effect was prevented by preincubating the vessels with ascorbic acid (10 mumol/l), superoxide dismutase (100 U/ml) and gliclazide (1 and 10 mumol/l), but not with indomethacin (10 mumol/l), catalase (400-600 U/ml), dimethylthiourea (1 mmol/l) or glibenclamide (10 mumol/l). In vessels preincubated with NG-nitro-L-arginine methyl ester (100 mumol/l), glycohaemoglobin did not add any additional effect.

CONCLUSION/INTERPRETATION

Highly glycated human oxyhaemoglobin, at physiological plasmatic concentrations, impairs nitric oxide-mediated responses by a mechanism involving superoxide anions but not cyclooxygenase derivatives.

Structural and functional studies of hemoglobin Moabit (alpha 86(F7) Leu-->Arg

An abnormal hemoglobin fraction was detected on high performance liquid chromatography profile performed for the measurement of glycated hemoglobin in a 55-year-old caucasian patient. The structural and functional studies were performed by standard techniques. Separation of hemoglobins by alkaline electrophoresis and by IEF revealed a slightly more rapid fraction than does Hb S. By acid electrophoresis, no abnormal Hb fraction could be observed. Separation of globin chains by electrophoresis demonstrated an alpha-chain variant and by chromatography, a fraction which eluted between beta and gamma globin chains. Tryptic digests and amino acid analysis have demonstrated a previously described substitution of Leu-->Arg alpha 86(F7).

In vivo evidence for the existence of a threshold for hyperglycemia-induced major fetal malformations: relevance to the etiology of diabetic teratogenesis

The present study was carried out to evaluate whether hyperglycemia-induced major fetal anomalies are thresholded phenomena. Streptozotocin (STZ)-treated female ICR mice were examined on day 19 of pregnancy by methods routinely used in Segment II teratological studies. Simultaneously, the glucose and hemoglobin A1c (HbA1c) levels in maternal-blood were measured and mice with glucose levels > 9.5 mmol/l (mean + 3 SD) were considered to be diabetic. The occurrence of litters with fetuses having gross structural anomalies was clearly associated with glucose levels > 27.8 mmol/l. A wide range of HbA1c levels (between 6 and 18 SD above the mean) were observed, within which only single malformed fetuses were found in the litters of diabetic females. A decreased pregnancy rate in diabetic ICR mice was associated with glucose levels > 16.7 mmol/l and with HBA1c levels > 6 SD above the mean. The results of this study suggest that there is a threshold glucose level associated with a clear increase of the number of litters with severely malformed fetuses in diabetic ICR mice. Results of this study also suggest the existence of HbA1c-associated factors determining, along with glucose, the teratogenic response of ICR mice to diabetes. The interpretation of results obtained in terms of the multifactorial/threshold model leads to the hypothesis that the teratogenic potential of diabetes may consist of two components; one associated with 'direct' teratogens perturbing developmental processes in embryos at a 'critical moment' in organogenesis, and a second component, associated with a direct or indirect influence of the diabetic environment on developmental processes in the preimplantation embryos.

Impairment of endothelium-dependent relaxation by increasing percentages of glycosylated human hemoglobin. Possible mechanisms involved

High levels of glycosylated human hemoglobin impair nitric oxide-mediated responses. However, the percentage of glycosylation for which this effect is observed and the mechanisms involved are unknown. We tested endothelium-dependent relaxations caused by acetylcholine in rat aortic segments either in control conditions or after preincubation with increasing percentages of glycosylated human hemoglobin. Human hemoglobin (1 and 10 nmol/L) inhibited endothelium-dependent relaxations only when glycosylated at 9% or higher. We evaluated the effect of 14% glycosylated human hemoglobin on acetylcholine-evoked responses in vessels preincubated with scavengers of superoxide anions, hydroxyl radical, or hydrogen peroxide (superoxide dismutase, deferoxamine, and catalase, respectively); with inhibitors of xanthine oxidase, cyclooxygenase, or thromboxane synthase (allopurinol, indomethacin, and dazoxiben, respectively); with blockers of thromboxane A2/prostaglandin H2 or endothelin receptors (SQ 30741 and BQ-123); and with the precursor of nitric oxide synthesis L-arginine. Superoxide dismutase abolished the effect of glycosylated hemoglobin, and the other substances did not have any effect. Glycosylated hemoglobin at 14% did not modify either the vasoconstrictions induced by the blocker of nitric oxide synthase NG-nitro-L-arginine methyl ester or the relaxations evoked in deendothelialized vessels by sodium nitroprusside and 8-bromo-cGMP. However, it inhibited the vasodilations evoked by exogenous nitric oxide. Superoxide dismutase abolished this latter effect. We conclude that the threshold for glycosylated human hemoglobin (Hb A1) to inhibit endothelium-dependent relaxation is 9%. This effect is due to interference with endothelial nitric oxide by means of superoxide anion production.

Influence of glycemic control on viscosity and density of plasma and whole blood in type-1 diabetic patients

The hemorheological properties of blood play an important role in determining blood flow. Blood inertia, as characterized by blood density, controls blood flow in the large arteries, whereas blood viscosity becomes increasingly important with decreasing vessel diameter. In order to evaluate the impact of glycemic control on the rheological properties of blood, we examined viscosity (shear range: 600-0.2 s-1) and density of plasma and whole blood in 26 Type-1 diabetic patients and in 24 healthy controls, matched for age and sex. The diabetic subjects were subdivided into two groups according to their degree of glycemic control: 14 patients with good (HbA1c = 7.1 +/- 0.6%), and 12 patients with poor control (HbA1c = 8.7 +/- 0.7%). Diabetic patients as a whole did not differ from healthy controls in any of the rheological parameters. Subdivision of the patients due to their degree of glycemic control led to a marked rheological separation of Type-1 diabetic subjects with significantly lower plasma (P < 0.008) and whole blood viscosity (P < 0.03 at 10 and 25 s-1), and plasma density (P < 0.05) in well controlled patients. Compared with healthy controls, well controlled diabetic patients had significantly lower values of viscosity (P < 0.005) and density (P < 0.05) of plasma. Poorly controlled patients, on the other hand, did not differ from healthy controls in the examined rheological parameters. There seems to be a positive influence of good glycemic control on hemorheology in Type-1 diabetic patients.

Interference of glycosylated human hemoglobin with endothelium-dependent responses

BACKGROUND

Hypertension and other vascular diseases are more prevalent in diabetic patients than in the general population. In humans and in several animal models of diabetes, a disturbance of endothelium-dependent responses has been shown. Oxyhemoglobin is one of the most known modulators of these endothelium-dependent responses. We postulate that high levels of plasmatic glycosylated hemoglobin, a frequent profile in diabetic patients, may be the cause of the disturbance in endothelium-dependent relaxation and/or contraction.

METHODS AND RESULTS

Endothelium-dependent responses to acetylcholine and several alpha-adrenergic agonists (norepinephrine, methoxamine, and clonidine) were tested in segments of rat aorta. Experiments were carried out in control segments and in those preincubated with several concentrations of nonglycosylated, low-glycosylated (7.3%), and high-glycosylated (14%) human hemoglobin. Low concentrations of high-glycosylated human hemoglobin (1 to 100 nmol/L) but not of low- or nonglycosylated hemoglobin, inhibited endothelium-dependent relaxation caused by acetylcholine in intact vessels. The same effect was observed on relaxations caused by nitric oxide in denuded ones. High-glycosylated human hemoglobin (10 nmol/L) induced an increase in norepinephrine-evoked contraction in intact vessels; this latter effect was also shown in vessels contracted with methoxamine but not with clonidine. De-endothelialization of the vascular segments blunted these effects of high-glycosylated human hemoglobin.

CONCLUSIONS

High glycosylation of human hemoglobin impairs endothelium-mediated vasoactive responses and may play a pathophysiological role in producing hypertension and vascular diseases in diabetic patients.

[Performance and utility of a quick immunological method for the measurement of HbAlc in a pediatric diabetes unit]

This study compares the results of a new immunoassay method (DCA2000, Ames) used to measure HbAlc concentration in 9 min using 1-microliter capillary blood sample with those obtained with an ion exchange traditional method (HPLC, DIAMAT, Biorad) in both a non-diabetic and a diabetic pediatric population. All HbAlc values were measured in the two methods on the same whole-blood venous aliquot after we had excluded differences in HbAlc values measured by DCA2000 on venous and capillary blood samples (8.5 +/- 1.4 vs 8.6 +/- 1.4%). Data analysis shows an excellent correspondence between the two assays (r = 0.97; p < 0.0001). HbAlc values obtained by DCA2000 method in diabetic patients are related to the mean value of the blood glucose levels collected at home in the last two months (r = 0.74; p < 0.003). The percentile distribution of the HbAlc values is similar both in DCA2000 (3-- = 4.4; 50-- = 5.3; 97-- = 6.0%) and in HPLC method (3-- = 4; 50-- = 5; 97-- = 5.9%). Within-run precision for DCA2000 ranges from 3.7 to 1.9% and between-run precision from 4.5 to 0.9%. The new immunoassay method gives accurate and reliable HbA1c values and compared with HPLC methodology has at least three advantages: it does not require venipuncture, provides HbA1c value within 9 miy and allows both physician and patient to verify in virtually' real time the degree of blood glucose control.

[Pathophysiology and prevention of retinopathy of prematurity]

In premature infants there is a temporal and causal relation between the change in the erythropoiesis after birth and the manifestation of retinopathy. The physiological substitution of the fetal erythrocytes can be controlled by an analysis of the fetal hemoglobin. In premature infants in which the erythropoiesis has not yet been converted there is an interval of time where there is a chronic hypoxemia of the retina and in which neovascularisation occurs. The oxygen deficit arises because fetal blood - in comparison with adult blood - exhibits a higher affinity to oxygen. If high values of HbF are ascertained in premature infants the chronic hypoxemia of the retina can be avoided by replacing the erythrocytes. In this way, a secondary prevention of the illness is possible.

Role of height and glycosylated hemoglobin in abnormal nerve conduction in pediatric patients with type I diabetes mellitus after 4-9 yr of disease

OBJECTIVE

To determine the role of height and glycosylated hemoglobin in abnormal nerve conduction in pediatric patients with insulin-dependent (type I) diabetes mellitus.

RESEARCH DESIGN AND METHODS

Sixty-six pediatric patients (aged 6.3-18.2 yr) with a duration of diabetes from 4 to 8.5 yr but free of clinical neuropathy were evaluated for abnormal nerve conduction.

RESULTS

Mean HbA1 values for 1 and 2 yr before study were available. Electroneurographic findings were significantly different from control subjects in upper and lower extremities and included all five measured velocities, three sensory latencies, and one amplitude. Stepwise regression analysis identified an adverse effect of height on latency (5 of 6) and of mean HbA1 concentration on decreasing velocity (4 of 5). The data analysis from 52 patients who were restudied and who had a duration of diabetes from 5.3 to 9.6 yr confirmed that all velocity values slowed; one of five values did so significantly. The coefficients associated with mean HbA1 concentration usually increased in both upper- and lower-extremity velocity analyses at the follow-up examination. The change in peroneal motor velocity between the first and last examinations was significantly related to the increasing time interval between examinations.

CONCLUSIONS

Prospective evaluation of nerve conduction parameters in pediatric patients with diabetes should include both height (the most significant independent variable in latency analysis) and mean glycemic control (the most consistent variable in velocity analyses) as variables in the assessment of the natural history of evolving peripheral neuropathy.

Role of advanced glycosylation products in complications of diabetes

Glucose and other reducing sugars can react with proteins and nucleic acids, without the aid of enzymes, to form stable covalent adduct. These reactions, although studied by food chemists, have recently been found to occur in vivo. This has led to studies on the accumulation of these advanced glycosylation end products (AGE) and the role it plays in the aging of long-lived proteins and nucleic acids. In contrast to the Amadori product, which is in equilibrium with glucose, AGE is irreversibly attached to the proteins. The AGE moieties are brown, fluorescent chromophores that can cross-link proteins. We have identified and characterized two specific AGE glucose-derived cross-links in proteins 2-furoyl-4(5)-(2-furanyl)-1H-imidazole (FFI) and 1-alkyl-2-formyl-3,4-diglycosylpyrrole (AFGP). By use of a radioimmunoassay for FFI identification, it has been possible to demonstrate the presence of FFI in situ in proteins that had been exposed to glucose in vitro and in vivo. Recently, we found that reducing sugars react with amino groups on DNA nucleotides in a manner analogous to the nonenzymatic glycosylation of amino groups on proteins. The AGE-DNA formed in this manner has spectral and fluorescent properties similar to those of AGE-proteins. We have observed that formation of AGE on DNA decreases the ability of the single-stranded virus f1 to transfect Escherichia coli. When the plasmid pBR322 containing ampicillin- and tetracycline-resistant genes is incubated with reducing sugars, specific mutations are observed. These mutations have been found to be caused by insertions and deletions of the DNA. Further studies are needed for measuring the amounts of AGE-DNA and proteins linked to DNA by AGE. Potential mechanisms for repair of AGE-DNA also needs to be explored further.(ABSTRACT TRUNCATED AT 250 WORDS)

Seasonality in glycosylated hemoglobin in normal subjects. Does seasonal incidence in insulin-dependent diabetes suggest specific etiology?

Seasonality in the diagnosis of insulin-dependent diabetes mellitus (IDDM), i.e., increased incidence in winter, was the impetus for this study of seasonality in glycosylated hemoglobin levels in nondiabetics. Glycosylated hemoglobin levels of 35 nondiabetic children and adults were highest at the ends of autumn and winter and lowest at the ends of spring and summer (P less than 10(-4)). This result is consistent with reports of seasonal variation in blood glucose, with the highest levels occurring in winter, as well as reports that suggest an internal milieu of increased counterinsulin action in winter due to seasonality in counterinsulin hormones, dietary factors, body weight, amount of exercise, growth rates in children, and ambient temperature. IDDM is caused by the gradual destruction of the pancreatic insulin-producing cells via lymphocytic infiltration--a process that may occur over years. We conclude that a decreased carbohydrate tolerance associated with winter can explain the seasonal variation in the incidence of IDDM and that this seasonality is caused by the precipitation of overt carbohydrate intolerance in individuals with already seriously compromised insulin secretory capacity. This implies that seasonality is not very formative about the cause of the destruction of pancreatic insulin-producing cells.