Evaluation of turbidimetric inhibition immunoassay (TINIA) and HPLC methods for glycated haemoglobin determination

Advanced cardiovascular physiology in an individual with type 1 diabetes after 10-year ketogenic diet

Adults with type 1 diabetes (T1D) have an elevated risk for cardiovascular disease (CVD) compared with the general population. HbA1c is the primary modifiable risk factor for CVD in T1D. Fewer than 1% of patients achieve euglycemia (<5.7% HbA1c). Ketogenic diets (KD; ≤50 g carbohydrate/day) may improve glycemia and downstream vascular dysfunction in T1D by reducing HbA1c and insulin load. However, there are concerns regarding the long-term CVD risk from a KD. Therefore, we compared data collected in a 60-day window in an adult with T1D on exogenous insulin who consumed a KD for 10 years versus normative values in those with T1D (T1D norms). The participant achieved euglycemia with an HbA1c of 5.5%, mean glucose of 98 [5] mg/dL (median [interquartile range]), 90 [11]% time-in-range 70-180 mg/dL (T1D norms: 1st percentile for all), and low insulin requirements of 0.38 ± 0.03 IU/kg/day (T1D norms: 8th percentile). Seated systolic blood pressure (SBP) was 113 mmHg (T1D norms: 18th percentile), while ambulatory awake SBP was 132 ± 15 mmHg (T1D target: <130 mmHg), blood triglycerides were 69 mg/dL (T1D norms: 34th percentile), low-density lipoprotein was 129 mg/dL (T1D norms: 60th percentile), heart rate was 56 beats/min (T1D norms: >1SD below the mean), carotid-femoral pulse wave velocity was 7.17 m/s (T1D norms: lowest quartile of risk), flow-mediated dilation was 12.8% (T1D norms: >1SD above mean), and cardiac vagal baroreflex gain was 23.5 ms/mmHg (T1D norms: >1SD above mean). Finally, there was no indication of left ventricular diastolic dysfunction from echocardiography. Overall, these data demonstrate below-average CVD risk relative to T1D norms despite concerns regarding the long-term impact of a KD on CVD risk.NEW & NOTEWORTHY Adults with type 1 diabetes (T1D) have a 10-fold higher risk for cardiovascular disease (CVD) compared with the general population. We assessed cardiovascular health metrics in an adult with T1D who presented with a euglycemic HbA1c after following a ketogenic diet for the past 10 years. Despite concerns about the ketogenic diet increasing CVD risk, the participant exhibited below-average CVD risk relative to others with T1D when considering all outcomes together.

Comparison of high performance liquid chromatography and turbidimetric inhibition immunoassay methods for measurement of hemoglobin A1c

Aim: Hemoglobin A1c is a valuable parameter for the diagnosis and follow-up of its diabetes mellitus since its biological variation is low, does not require preparation before the test, is not affected by acute stress, and has high preanalytical stability. HbA1c measurement by HPLC has been determined as the reference method by National Glycohemoglobin Standardization Program (NGSP) in USA; after that The International Federation of Clinical Chemistry (IFCC) defined another reference method which could be related with NGSP. In our study, we aim to compare the two NGSP-certified methods of HbA1c, which are high-performance liquid chromatography (HPLC) and turbidimetric inhibition immunoassay (TINIA). Material and Method: HbA1c levels of the patients were measured using two HPLC and one TINIA method in three different hospitals (Lab A, Lab B (Both are HPLC), and Lab C (TINIA), in which Lab A was served as a reference). Because of the lower precision values of LabB, we firstly conducted a method comparison study of 40 volunteers (Group 1). After that, corrective and preventive activities carried out and the precision values in LabB reached the desired range. Following this, another method comparison study consisting of 60 new volunteers (Group 2) was conducted. The statistical flow of this study complied with Clinical Laboratory Standards Institute (CLSI) EP09-A3; Precision studies, Blant-Altman and Passing Bablok regression analysis were performed. Results: The percentage of the mean difference between the two HPLC methods (LabA and LabB) was 3.1%. After corrective and preventive actions had been taken, the mean difference between the two HPLC methods decreased to 2.0%. A decrease in systematic bias was found in our study. Two HPLC methods can be used interchangeably in both Group 1 and Group 2. In Group 1; 95% CI of intercept and slope were found as (-1.41 to -0.30) and (1.03 to 1.22), respectively. In Group 2; 95% CI of intercept and slope were found as (-1.33 to -0.31) and (1.01 to 1.17), respectively. HPLC and TINIA methods could not be used interchangeable without affecting patient results and outcome in both Group 1 and Group 2. Conclusion: Our study concluded that TINIA and HPLC methods could not be used interchangeably without affecting patient results and outcome. Because of the methodology that clinical laboratories are used to, clinicians and clinical biochemists should collaborate on managing diabetes mellitus regarding diagnosis, treatment, and follow-up.

The Association between Vitamin D Hypovitaminosis and Cardiovascular Disease Risk in Saudi Diabetic Patients Type II

We evaluated the prevalence and association of Vitamin D deficiency with glycemic control and CVD risk in T2DM patients. Serum 25 (OH)D3, lipid profile, glucose panel, HbA1c, serum insulin, and HOMA-IR were assessed in 93 T2DM patients and 69 controls. 10 years and lifetime ASCVD risk scores were calculated. The levels of 25(OH)D3 were significantly low in T2DM patients compared to the control. T2DM patients with hypovitaminosis D displayed significantly increased FBG, insulin, and HOMA-IR compared to normovitaminosis. Their lifetime and 10-year ASCVD risk scores were significantly higher regardless of vitamin D deficiency levels (P=0.006; P=0.023) in comparison to patients with sufficient levels of vitamin D. Among patients, the lifetime and 10 years of ASCVD risk showed a significant negative correlation with serum 25(OH)D3 and HDLc (P=0.037; 0.018) (P=0.0001), respectively, and significant positive correlation with T2DM duration, serum insulin, and HOMA-IR (P=0.018; 0.0001) (P=0.002; 0.001) (P=0.005; 0.001), respectively. The 10-year ASCVD risk exhibited a significant positive correlation with FBG (P=0.003) and HbA1c (P=0.009). T2DM duration was a predictor of vitamin D deficiency among T2DM patients (β = 0.22; CI = 0.002-0.04). There is a considerable association between lifetime and 10 years of ASCVD risk with hypovitaminosis D in T2DM, regardless of the deficiency levels which could be predicted by the diabetes duration.

The Accuracy of Hemoglobin A1c and Fructosamine Evaluated by Long-Term Continuous Glucose Monitoring in Patients with Type 2 Diabetes Undergoing Hemodialysis

INTRODUCTION

The accuracy of hemoglobin A1c (HbA1c) as a glycemic marker in patients with type 2 diabetes (T2D) receiving hemodialysis (HD) remains unknown. To assess accuracy, we compared HbA1c and fructosamine levels with interstitial glucose measured by continuous glucose monitoring (CGM) in patients with T2D receiving HD.

METHODS

Thirty patients in the HD group and 36 patients in the control group (T2D and an estimated glomerular filtration rate >60 mL/min/1.73 m2) completed the study period of 17 weeks. CGM (Ipro2®, Medtronic) was performed 5 times for periods of up to 7 days (with 4-week intervals) during a 16-week period. HbA1c (mmol/mol), the estimated mean plasma glucose from HbA1c (eMPGA1c [mmol/L]) and fructosamine (μmol/L) was measured at week 17 and compared with mean sensor glucose levels from CGM.

FINDINGS

In the HD group, mean sensor glucose was 1.4 mmol/L (95% confidence interval [CI]: 1.0-1.8) higher than the eMPGA1c, whereas the difference for controls was 0.1 mmol/L (95% CI: -0.1-[0.4]; p < 0.001). Adjusted for mean sensor glucose, HbA1c was lower in the HD group (-7.3 mmol/mol, 95% CI: -10.0-[-4.7]) than in the control group (p < 0.001), with no difference detected for fructosamine (p = 0.64).

DISCUSSION

HbA1c evaluated by CGM underestimates plasma glucose levels in patients receiving HD. The underestimation represents a clinical challenge in optimizing glycemic control in the HD population. Fructosamine is unaffected by the factors affecting HbA1c and appears to be more accurate for glycemic monitoring. CGM or fructosamine could thus complement HbA1c in obtaining more accurate glycemic control in this patient group.

Comparison of Turbidimetric Inhibition Immunoassay, High-Performance Liquid Chromatography, and Capillary Electrophoresis Methods for Glycated Hemoglobin Determination

OBJECTIVE

The purpose of this study was to compare the performances of and evaluate the agreement among glycated hemoglobin values analyzed by using National Glycohemoglobin Standardization Program-certified and International Federation of Clinical Chemistry-standardized analyzers.

THIS CROSS-SECTIONAL STUDY WAS CONDUCTED AT THE

Armed Forces Institute of Pathology, Department of Chemical Pathology from March 2019 to May 2019.

METHODS

Glycated hemoglobin (HbA1c) was measured in the blood specimens from 100 patients on an ADVIA 1800 by a turbidimetric inhibitory immunoassay (TINIA), Sebia instrument by electrophoresis, and Bio-Rad Variant II Turbo system by high-performance liquid chromatography (HPLC). Quantitative variables were calculated as the mean ± standard deviation (SD). Precision and method comparisons were carried out according to Clinical and Laboratory Standards Institute recommendations. The results obtained from each analyzer were compared by correlation analysis. Method comparison was done by linear regression and Bland-Altman plots using the SPSS software version 24.

RESULTS

The mean ± SD HbA1c values from TINIA, electrophoresis, and HPLC were 7.188% ± 1.89%, 7.164% ± 1.866%, and 7.160% ± 1.85%, respectively. The between-run coefficients of variation for TINIA, electrophoresis, and HPLC were 0.64%, 0.61%, and 0.60%, respectively. All 3 showed good correlation (TINIA, R2 = .994, P = .00; electrophoresis, R2 = .992, P = 0.00; and HPLC, R2 = .994, P = 0.00).

CONCLUSION

The good clinical agreements of HbA1c and strong correlations between analyzers indicate that these analyzers can be used interchangeably.

Diabetes Attenuates the Contribution of Endogenous Nitric Oxide but Not Nitroxyl to Endothelium Dependent Relaxation of Rat Carotid Arteries

Endothelial dysfunction is a major risk factor for several of the vascular complications of diabetes, including ischemic stroke. Nitroxyl (HNO), the one electron reduced and protonated form of nitric oxide (NO•), is resistant to scavenging by superoxide, but the role of HNO in diabetes mellitus associated endothelial dysfunction in the carotid artery remains unknown. Aim: To assess how diabetes affects the role of endogenous NO• and HNO in endothelium-dependent relaxation in rat isolated carotid arteries. Methods: Male Sprague Dawley rats were fed a high-fat-diet (HFD) for 2 weeks prior to administration of low dose streptozotocin (STZ; 35 mg/kg i. p./day) for 2 days. The HFD was continued for a further 12 weeks. Sham rats were fed standard chow and administered with citrate vehicle. After 14 weeks total, rats were anesthetized and carotid arteries collected to assess responses to the endothelium-dependent vasodilator, acetylcholine (ACh) by myography. The combination of calcium-activated potassium channel blockers, TRAM-34 (1 μmol/L) and apamin (1 μmol/L) was used to assess the contribution of endothelium-dependent hyperpolarization to relaxation. The corresponding contribution of NOS-derived nitrogen oxide species to relaxation was assessed using the combination of the NO• synthase inhibitor, L-NAME (200 μmol/L) and the soluble guanylate cyclase inhibitor ODQ (10 μmol/L). Lastly, L-cysteine (3 mmol/L), a selective HNO scavenger, and hydroxocobalamin (HXC; 100 μmol/L), a NO• scavenger, were used to distinguish between NO• and HNO-mediated relaxation. Results: At study end, diabetic rats exhibited significantly retarded body weight gain and elevated blood glucose levels compared to sham rats. The sensitivity and the maximal relaxation response to ACh was significantly impaired in carotid arteries from diabetic rats, indicating endothelial dysfunction. The vasorelaxation evoked by ACh was abolished by L-NAME plus ODQ, but not affected by the apamin plus TRAM-34 combination, indicating that NOS-derived nitrogen oxide species are the predominant endothelium-derived vasodilators in sham and diabetic rat carotid arteries. The maximum relaxation to ACh was significantly decreased by L-cysteine in both sham and diabetic rats, whereas HXC attenuated ACh-induced relaxation only in sham rats, suggesting that diabetes impaired the contribution of NO•, whereas HNO-mediated vasorelaxation remained intact. Conclusion: Both NO• and HNO contribute to endothelium-dependent relaxation in carotid arteries. In diabetes, NO•-mediated relaxation is impaired, whereas HNO-mediated relaxation was preserved. The potential for preserved HNO activity under pathological conditions that are associated with oxidative stress indicates that HNO donors may represent a viable therapeutic approach to the treatment of vascular dysfunction.

Dapagliflozin improves cardiovascular risk factors in Emirati patients with T2DM

BACKGROUND

Dapagliflozin is a sodium-glucose co transporter-2 inhibitor that proved efficacy in reduction of blood glucose level through extrusion of glucose in urine. It is used in treatment of type 2 diabetes mellitus (T2DM). It also has reported cardiovascular and renal benefits in patients with T2DM. Data are very limited about its effects in Emirati patients with diabetes. Our aim was to evaluate dapagliflozin treatment in Emirati patients with T2DM.

PATIENTS AND METHODS

This is a retrospective study involving 89 diabetes patients who were using dapagliflozin 10 mg once daily as add-on therapy for 12 months. All patients had T2DM, aged over 18 years and had an estimated glomerular filtration rate (eGFR) over 60 ml/min/1.73 m². Body weight, height, body mass index, sitting blood pressure and heart rate were collected. Fasting plasma glucose, glycosylated hemoglobin (HbA1c), lipid profile and other available biochemical parameters, for example, creatinine, blood urea nitrogen, and urine albumin/creatinine ratio were traced from medical records and eGFR was calculated.

RESULTS

Patients were aged 62.3 ± 9.4 years with a median duration of diabetes of 15 (10-20) years. Data were analyzed before, at 6 months and 12 months of treatment. Fasting plasma glucose, HbA1c, body mass index, systolic and diastolic blood pressure significantly decreased (p = 0.002, p < 0.0005, p < 0.002, p < 0.0005, p < 0.0005, respectively). The median reduction of HbA1c was 0.7% (0.2-1.2) and 0.9% (0.5-1.8) at 6 and 12 months, respectively. Systolic blood pressure decreased by a median of 7 mmHg (4-20 mmHg) and 9 mmHg (1-10 mmHg) on the 6th and 12th month of treatment, respectively, while the diastolic decreased by a median of 3 mmHg (4 to 10 mmHg) and 6 mmHg (1-10 mmHg); without increase in heart rate (p = 0.188). A significant reduction of body mass index, C-reactive protein and rate pressure product was noticed (p = 0.002, p = 0.001, p < 0.0005, respectively). No decline in eGFR or microalbuminuria was noticed. Stage I chronic kidney disease with eGFR < 90 ml/min/1.73 m² showed continuous progressive reduction of HbA1c without a significant change in other variables.

CONCLUSION

Our data indicate improved cardiovascular risk profile in dapagliflozin-treated Emirati patients with T2DM.

Worksite intervention study to prevent diabetes in Nepal: a randomised trial protocol

INTRODUCTION

In Nepal, approximately 31% of adult industrial employees have diabetes. While the prevention of type 2 diabetes through behavioural intervention has been disseminated, worksite could be an effective platform for the translation of this knowledge into action as employed adults spend most of their workday waking hours at workplaces.

METHODS AND ANALYSIS

We will conduct a randomised controlled trial to assess the effectiveness of a behavioural and a canteen intervention on diabetes risk reduction among those who are prediabetic at two worksites in eastern Nepal. We will recruit 162 adult full-time factory workers with haemoglobin A1c (HbA1c) of 5.7%-6.4% at baseline or fasting blood sugar of 100-125 mg/dL. The 8-14 months' control period will be followed by the behavioural intervention where half of the participants will be randomised to receive the behavioural intervention and half will act as a control and will not receive any intervention. Then, all participants will receive the canteen intervention. The analysis will be intent-to-treat, comparing the difference in the change in HbA1c% between the behavioural intervention group and the control group using a two-sample t-test. The within-participant changes in HbA1c after 6 or more months on the canteen intervention among those not randomised to the behavioural intervention in the previous period will be assessed using the paired t-test.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Institutional Review Board at Yale School of Public Health, New Havens, USA and the Nepal Health Research Council.

TRIAL REGISTRATION NUMBER

NCT04161937.

Correlation of Body Mass Index and Waist/Hip Ratio with Glycated Hemoglobin in Prediabetes

INTRODUCTION

Prediabetes (preDM) is a state of disordered glucose metabolism rather than a distinctive clinical entity representing an interim condition and a risk factor for the development of diabetes. Diagnosis of asymptomatic people to assess the risk for development of DM should be done in overweight or obese adults (BMI ≥ 25 kg/m²) of any age along with person having one or more additional risk factors like physical inactivity, first degree relative with DM, high risk race/ethnicity, hypertension etc.

OBJECTIVES

To correlate glycated hemoglobin (HbA_1c) levels with body mass index (BMI) and waist hip ratio (WHR) in prediabetic patients.

MATERIALS & METHODS

The present case control study was performed at Pt. B. D. Sharma PGIMS, Rohtak includes thirty prediabetic patients of age group 20-40 years diagnosed on the basis of HbA_1c (5.7-6.4%). Thirty healthy and age matched control were taken. After taking written consent, they were subjected to physical examination and anthropometric measurements as per protocol and findings were noted. Venous blood sample was withdrawn for estimation of HbA_1c levels.

RESULTS

The correlation coefficient between BMI (27.01 ± 2.91 kg/m²) and HbA_1c (5.94 ± 0.21%) is r = 0.583 with p value = 0.001 and between WHR (0.87 ± 0.38) & HbA_1c is r = 0.495 with p value = 0.005. Both BMI & WHR are positively correlated with HbA_1c.

CONCLUSION

Obesity is a risk factor for glycation of hemoglobin & hence, it is an effective measure for prevention of prediabetes and diabetes.

Neuropathic pain is not associated with serum vitamin D but is associated with female gender in patients with type 2 diabetes mellitus

OBJECTIVE

Neuropathic pain is a common complication of diabetes mellitus (DM). Patients may complain of several neuropathic symptoms including impaired peripheral sensation, numbness, tingling, burning, and pain. Because these symptoms may cross with symptoms of vitamin D deficiency, we hypothesized that neuropathic pain and vitamin D deficiency may be associated in patients with type 2 DM.

RESEARCH DESIGN AND METHODS

This is a cross-sectional study that involved 239 participants with type 2 DM. Neuropathic pain was assessed using PainDETECT questionnaire. Serum 25-hydroxyvitamin D was measured by the electrochemiluminescence immunoassay, fasting blood glucose was measured by the hexokinase method and hemoglobin A1c was measured by the turbidimetric inhibition immunoassay.

RESULTS

The prevalence of neuropathic pain among type 2 DM participants was 26.8%. Vitamin D deficiency was reported in 67.8% of type 2 DM participants. The neuropathy score for females was significantly higher than that for males (p<0.01). There was no significant difference in serum vitamin D between type 2 DM participants according to their gender and according to their neuropathy status (p>0.05). Ordinal logistic regression analysis has shown that female gender was the only significant predictor of neuropathic pain among type 2 DM participants (p<0.01 with an OR (95% CI) of 2.45 (1.29 to 4.67)).

CONCLUSIONS

Neuropathic pain was not associated with serum vitamin D but was associated with female gender in type 2 DM. Because our results were not consistent with other studies that used different neuropathy assessment tools, we suggest that further research should be conducted to check the validity of these tools in identifying subjects with neuropathy.

Association between serum 25-hydroxyvitamin D, hemoglobin A1c and fasting blood glucose levels in adults with diabetes mellitus

In the present study, the aim was to investigate the association between serum 25-hydroxyvitamin D concentration and measures of glycemic control including hemoglobin A1c (HbA1c) and fasting blood glucose (FBG) in adult patients with diabetes mellitus (DM) from the north of Jordan. Another aim was to compare serum levels of 25-hydroxyvitamin D between patients with good glycemic control and patients with uncontrolled DM. This was a cross-sectional study that included 261 participants with DM. The concentration of 25-hydroxyvitamin D was measured using electrochemiluminescence immunoassay, HbA1c was measured using turbidimetric inhibition immunoassay and FBG was measured using the hexokinase method. Data regarding other clinical variables were obtained from medical records or by self-reporting. Participants with good glycemic control exhibited significantly higher levels of 25-hydroxyvitamin D compared with participants with uncontrolled DM (P=0.03). Participants with sufficient vitamin D status (>30 ng/ml in serum) exhibited significantly lower HbA1c level compared with participants with deficient vitamin D (<20 ng/ml) status (P=0.02). Correlation analysis determined significant inverse correlations between 25-hydroxyvitamin D levels and HbA1c and FBG levels (r=-0.23 and -0.17, respectively, both P<0.01). There were also significant correlations between duration of DM and HbA1c and FBG levels (both r=0.21, P<0.01). HbA1c level was also inversely correlated with participants' age (r=-0.19, P<0.01). Further multiple linear regression analysis revealed an inverse significant association between HbA1c and 25-hydroxyvitamin D levels (F=12.95, R²=0.48, P<0.01) but did not identify a similar association between FBG and 25-hydroxyvitamin D levels. These findings may encourage further research to identify if vitamin D supplementation may improve measures of glycemic control, and how vitamin D may affect glucose homeostasis in patients with DM.

Prevalence of musculoskeletal pain in association with serum 25-hydroxyvitamin D concentrations in patients with type 2 diabetes mellitus

The aim of the present study was to investigate the prevalence of musculoskeletal pain in patients with type 2 diabetes mellitus (T2DM) in association with 25-hydroxyvitamin D levels, anxiety, depression and neuropathy. A cross-sectional study was conducted involving a total of 124 T2DM patients. Musculoskeletal pain was determined by self-reporting of painful body sites. Pain intensity was assessed using a scale of 0-10. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale. Neuropathy was assessed using the PainDETECT questionnaire. The concentration of 25-hydroxyvitamin D was measured using liquid chromatography-tandem mass spectrometry. Fasting blood sugar (FBS) was determined using the hexokinase method and glycated hemoglobin (HbA1c) level was determined using turbidimetric inhibition immunoassay. The neck, lower back and head were reported as the most common painful sites (affected in 60.5, 60.5 and 56.5% of patients, respectively). Pain in the lower extremities, including the knees, lower legs and feet, was more common compared with pain in the upper extremities. The pain measurements of number of painful sites and pain intensity did not differ significantly among patients with sufficient (>30 ng/ml), insufficient (20-30 ng/ml) and deficient (<20 ng/ml) vitamin D levels (P>0.05). The pain measurements were identified to have no correlation with age, body mass index, FBS, HbA1c level, 25-hydroxyvitamin D concentration, anxiety or depression (P>0.05). However, the pain measurements were correlated with duration of T2DM and neuropathy score (P<0.05). Further regression analysis demonstrated that the pain measurements were significantly associated with the neuropathy score (P<0.05). In conclusion, musculoskeletal pain in patients with T2DM was not associated with 25-hydroxyvitamin D concentration, but was associated with neuropathy score. This may encourage further investigations to assess the etiology of musculoskeletal pain in T2DM, and whether vitamin D supplementation and management of neuropathy would be of value as pain relief treatment.

Fasting plasma glucose and variation in cardiometabolic risk factors in people with high-risk HbA1c-defined prediabetes: A cross-sectional multiethnic study

AIMS

Variation in cardiometabolic risk in prediabetes and any impacts of ethnicity on such variation have been little studied. In an ethnically diverse dataset, selected according to a high-risk HbA1c-based definition of prediabetes, we have investigated relationships between glycaemia and cardiometabolic risk factors and the influence of ethnicity on these relationships.

METHODS

We undertook a cross-sectional analysis of baseline data from a diabetes prevention study in the UK and a chronic care clinic in Thailand, selected for people without diabetes (fasting plasma glucose <7.0 mmol/l) with HbA1c 6.0-6.4% (42-47 mmol/mol). Thai (n=158) and UK White (n=600), South Asian (n=112), Black (n=70) and other/mixed (n=103) groups were distinguished and measurements included fasting plasma glucose (FPG), blood pressure (BP), lipids and insulin resistance-related risk factors (IRFs).

RESULTS

Independently of individual characteristics including ethnicity, only systolic BP was weakly associated with FPG (beta coefficient 1.76 (95%CI 0.10-3.42), p 0.03) and only LDL-c with IFG (FPG 5.6 to <7) (adjusted -0.14 (-0.27, -0.003) p 0.04). There were no significant independent associations with cardiometabolic risk factors when categories of impaired fasting glucose (FPG ≥ 6.1 to <7.0 mmol/L) were considered. Relative to White, South Asian ethnicity was independently associated with lower systolic and diastolic BP, Black with lower triglycerides, cholesterol/HDL-c ratio and having 2 or more IRFs, and Thai with lower cholesterol/HDL-c ratio and all three non-white ethnicities with lower total and LDL cholesterol.

CONCLUSION

In high-risk HbA1c-defined prediabetes additional measurement of FPG will add little to evaluation of cardiometabolic risk. Additionally, UK Whites tend to have the most adverse cardiometabolic profile of any ethnic group.

Cholecalciferol improves glycemic control in type 2 diabetic patients: a 6-month prospective interventional study

Background and purpose

To investigate the effects of vitamin D supplementation on glucose homeostasis and lipid profile in type 2 diabetic patients who have vitamin D deficiency.

Patients and methods

One hundred twenty-five type 2 diabetic patients taking oral hypoglycemic agents as mono- or combination therapy were recruited from the diabetes and endocrinology clinic. Subject demographics, duration of diabetes, antidiabetic medication, body mass index (BMI), pulse, and blood pressure (BP) were assessed. Laboratory measurements of serum vitamin D3 level, hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and lipid profile were measured. Homeostatic model assessment-insulin resistance (HOMA-IR) was calculated whenever fasting insulin (FI) was available. Forty-one patients (27 males and 14 females) were started on cholecalciferol replacement–45,000 units once weekly for 8 weeks and then 22,500 units once weekly for 16 weeks. Calcium carbonate tablets 500 mg once daily were also prescribed for the initial 2 months of treatment. Measured variables were reassessed after 6 months of replacement therapy. During the trial, subjects were instructed not to change their diabetes drugs or lifestyle.

Results

No significant association was found between vitamin D3 level and any of the measured variables apart from a significant positive correlation with blood urea nitrogen. Vitamin D3 replacement was associated with a significant increase in its level (14.0±4.0 vs 31.0 vs 7.9 ng/mL, P<0.001). This was associated with a significant reduction of HbA1c (7.9±1.7 vs 7.4%±1.2%, P=0.001) and FPG (9.1±4.3 vs 7.9±2.4 mmol/L, P=0.034). Mean reduction of HbA1c was 0.54% and that of FPG was 1.22 mmol/L. FI, c-peptide and insulin resistance (IR) were reduced but this was statistically insignificant (P=0.069, 0.376, 0.058, respectively). FI decreased by 22%, HOMA-IR by 27.6%, and c-peptide by 1.83%. Total cholesterol, low-density lipoprotein cholesterol, parathyroid hormone, alkaline phosphatase, serum creatinine, and pulse rate significantly decreased (4.3±0.9 vs 4.0±0.9 mmol/L, P=0.036; 2.5±0.8 vs 2.2±0.8 mmol/L, P=0.018; 4.6±2.1 vs 3.5±1.8 pmol/L, P=0.001; 82.1±26.2 vs 66.2±19.5 U/L, P<0.001; 74.6±15.6 vs 70.7±14.7 μmol/L, P=0.047; and 81.6±11.9 vs 77.5±12.0 bpm, P=0.045, respectively). Triglycerides and high-density lipoprotein cholesterol, both systolic and diastolic BP, and BMI did not show significant change.

Conclusion

Cholecalciferol helps improve blood glucose control and cholesterol profile in vitamin D3-deficient type 2 diabetic patients.

A comparative evaluation of the analytical performances of Capillarys 2 Flex Piercing, Tosoh HLC-723 G8, Premier Hb9210, and Roche Cobas c501 Tina-quant Gen 2 analyzers for HbA1c determination

INTRODUCTION

Haemoglobin A_1c (HbA_1c) is widely used in the management of diabetes. Therefore, the reliability and comparability among different analytical methods for its detection have become very important.

MATERIALS AND METHODS

A comparative evaluation of the analytical performances (precision, linearity, accuracy, method comparison, and interferences including bilirubin, triglyceride, cholesterol, labile HbA_1c (LA_1c), vitamin C, aspirin, fetal haemoglobin (HbF), and haemoglobin E (Hb E)) were performed on Capillarys 2 Flex Piercing (Capillarys 2FP) (Sebia, France), Tosoh HLC-723 G8 (Tosoh G8) (Tosoh, Japan), Premier Hb9210 (Trinity Biotech, Ireland) and Roche Cobas c501 (Roche c501) (Roche Diagnostics, Germany).

RESULTS

A good precision was shown at both low and high HbA_1c levels on all four systems, with all individual CVs below 2% (IFCC units) or 1.5% (NGSP units). Linearity analysis for each analyzer had achieved a good correlation coefficient (R² > 0.99) over the entire range tested. The analytical bias of the four systems against the IFCC targets was less than ± 6% (NGSP units), indicating a good accuracy. Method comparison showed a great correlation and agreement between methods. Very high levels of triglycerides and cholesterol (≥ 15.28 and ≥ 8.72 mmol/L, respectively) led to falsely low HbA_1c concentrations on Roche c501. Elevated HbF induced false HbA_1c detection on Capillarys 2FP (> 10%), Tosoh G8 (> 30%), Premier Hb9210 (> 15%), and Roche c501 (> 5%). On Tosoh G8, HbE induced an extra peak on chromatogram, and significantly lower results were reported.

CONCLUSIONS

The four HbA_1c methods commonly used with commercial analyzers showed a good reliability and comparability, although some interference may falsely alter the result.

Clinicopathologic characteristics, prevalence, and risk factors of spontaneous diabetes in sooty mangabeys (Cercocebus atys)

In 2008, clinical observations in our colony of sooty mangabeys (Cercocebus atys) suggested a high frequency of type 2 diabetes. Postmortem studies of diabetic animals revealed dense amyloid deposits in pancreatic islets. To investigate these findings, we screened our colony (97 male mangabeys; 99 female mangabeys) for the disease from 2008 to 2012. The overall prevalence of diabetes was 11% and of prediabetes was 7%, which is nearly double that reported for other primate species (less than 6%). Fructosamine and triglyceride levels were the best indicators of diabetes; total cholesterol and glycated hemoglobin were not associated with disease. Increasing age was a significant risk factor: prevalence increased from 0% in infants, juveniles, and young adults to 11% in adults and 19% in geriatric mangabeys. Sex, medroxyprogesterone acetate exposure, and SIV status were unrelated to disease. Weight was marginally higher in prediabetics, but body condition did not indicate obesity. Of the 49 mangabeys that were necropsied after clinical euthanasia or death from natural causes, 22 were diabetic; all 22 animals demonstrated pancreatic amyloid, and most had more than 75% of islets replaced with amyloid. We conclude that type 2 diabetes is more common in mangabeys than in other primate species. Diabetes in mangabeys has some unusual pathologic characteristics, including the absence of altered cholesterol levels and glycated hemoglobin but a robust association of pancreatic insular amyloidosis with clinical diabetes. Future research will examine the genetic basis of mangabey diabetes and evaluate additional diagnostic tools using imaging and serum markers.

Hb H Interference on Measurement Of HbA1c With Ion-Exchange HPLC

In this article, an interference caused by hemoglobin H (Hb H), during the measurement of hemoglobin A1c (HbA1c) with ion exchange high pressure liquid chromatography (HPLC) method, was presented in blood sample of a 20-year-old male patient. HbA1c measurement was performed with Agilent 1200 HPLC system using a commercial Recipe HbA1c ion-exchange column. Hemoglobin electrophoresis was performed with Interlab G26 agarose electrophoresis automated compact system. HbA1c level was 18.2% and HbA0 level was 81.5% with ion-exchange HPLC method. Patient’s fasting serum glucose was assessed before HbA1c measurement and the result was 165 mg/dL (9.16 mmol/L). On the other hand, the result of HbA0 was 87.9%, Hb H was 10.8% and Hb A2 was 1.3% with electrophoresis. Whole blood test values were within reference ranges except MCV. MCV value was 79.6 fL. It is important to keep in mind that HbA1c level might be considered falsely high with ion-exchange HPLC method because of Hb H containing sample.