Evaluation of glycated albumin levels in tears and saliva as a marker in patients with diabetes mellitus.

AIMS: Glycated albumin (GA) is a biomarker, whose level reflects glycemic control status over the previous 2 weeks. To develop a non-invasive method for evaluating glycemic control in people with diabetes mellitus, we investigated the measurement of GA levels in tears and saliva, which could be collected noninvasively. METHODS: Tear and saliva samples were collected from 48 participants with diabetes mellitus. The GA levels in the tear and saliva specimens were measured by Liquid Chromatography-Mass Spectrometry (LC-MS/MS). RESULTS: GA levels in both tear and saliva samples were significantly correlated with the GA levels in the blood (P < 0.001). Multiple regression analysis revealed that these correlations were maintained even after adjustments for the BMI, age, and nephropathy stage (P < 0.001). CONCLUSION: GA levels in tear and saliva specimens, as diabetes-related biomarkers, can be measured non-invasively. Since this measurement can be performed noninvasively and not as frequently as compared with the more invasive finger prick method, it is expected to reduce the burden on people with diabetes in terms of both the invasiveness and cost-effectiveness. In the future, we would like to verify the effect of regular GA measurement on the glycemic control while considering the clinical cost-effectiveness.

Measurement of erythrocyte creatine might be useful for diagnosing latent hemolysis.

OBJECTIVES: Whereas HbA1c values are low relative to glycemia in patients with hemolytic anemia, including compensatory anemia, low HbA1c levels along with negative results for conventional hemolysis indicators have been reported in patients with latent hemolysis. Conversely, glycated albumin (GA) is a glycemic control indicator unaffected by hemolysis. Erythrocyte creatine (EC) is a hemolysis indicator that reflects the mean age of red blood cells (MRBC). We recently reported a formula for obtaining MRBC based on EC. The present study examined the usefulness of EC measurements and MRBC calculated with EC for diagnosing latent hemolysis. MATERIALS AND METHODS: Two patients with latent hemolysis and low HbA1c values relative to glycemia were investigated, while controls comprised 214 patients (including patients with hemolysis and/or type 2 diabetes mellitus). HbA1c was expressed in International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) units (iA1c). GA/iA1c ratios, reticulocyte counts, EC, and MRBC in patients with latent hemolysis were compared to non-hemolysis, compensatory hemolysis, and hemolytic anemia patients. RESULTS: Both reticulocyte counts and haptoglobin levels were within reference ranges in patients with latent hemolysis. GA/iA1c ratios and EC were higher than reference values in patients with latent hemolysis, and MRBC values were 41.6 and 48.4 days, respectively, shorter than the reference range (49.1-66.8 days). CONCLUSIONS: EC measurement and MRBC values calculated on the basis of EC might be useful for diagnosing latent hemolysis.

Characteristics of nephropathy in severely obese Japanese patients complicated with type 2 diabetes mellitus: a cross-sectional cohort study.

PURPOSE: We aimed to investigate the characteristics of kidney disease in severely obese Japanese patients with type 2 diabetes mellitus (T2DM). METHODS: This was a cross-sectional study of severely obese patients (body mass index ≥35 kg/m2) with T2DM treated at Jinnouchi Hospital, Kumamoto, Japan. RESULTS: A total of 3128 T2DM patients visited the hospital during the survey period, of whom 55 patients (1.7%) were severely obese and 50 patients were enrolled. In terms of diabetic nephropathy (DN), twenty-five patients were stage 1 (non-DN, 50.0%), sixteen were stage 2 (32.0%), five were stage 3 (10.0%), and four were stage 4 (8.0%). There were significant differences in the presence of urinary occult blood (P = 0.01) and history of cardiovascular disease (CVD) (P = 0.04) between patients with DN (stages 2-4) and those without DN (stage 1). The presence of urinary occult blood (odds ratio [OR], 4.96; 95% confidence interval, 1.32-18.6; P = 0.02) was significantly associated with the presence of DN according to multivariate logistic regression analysis with forced inclusion of age, sex, and CVD history. CONCLUSIONS: Urinary occult blood may be a significant independent factor associated with the presence of nephropathy in severely obese Japanese patients with T2DM. The presence of urinary occult blood could thus be an important pathogenic factor in obesity-related nephropathy in patients with T2DM.

Usefulness of Plasma Glucose Adjusted #C (labile HbA1c fraction) Levels for the Screening of Variant Hemoglobin with Diabetes Mellitus.

Labile HbA1c migrates in the #C fraction with modified hemoglobin (Hb) (such as carbamylated Hb, acetaldehyde Hb, and acetylated Hb) when HbA1c is measured by Arkray's high-performance liquid chromatography (HPLC). We previously reported the usefulness of #C levels for the screening of variant Hb without diabetes mellitus. Because the #C levels are affected by plasma glucose levels, we investigated the usefulness of plasma glucose adjusted #C (PGa#C) for the screening of variant Hb complicated with diabetes mellitus. In this study, nine types of variant Hb in nine diabetic patients were included. HbA1c and the #C fraction were measured by Arkray's HPLC. Furthermore, we established a calculation formula for PGa#C by using the regression equation of #C and plasma glucose of 2,299 diabetic patients without variant Hb. If the cutoff value of PGa#C for the screening of variant Hb with diabetes mellitus was set at 1.3% or lower and 2.3% or higher, sensitivity and specificity were 89% and 99.8%, respectively. The PGa#C levels in all four slow moving variant Hb with diabetes were less than 1.3%, while the PGa#C levels of fast moving variant Hb with diabetes were abnormal values in four out of five patients [high #C level in one and low #C levels in three patients]. The screening of variant Hb with diabetes with high sensitivity and high specificity was possible by using the same cutoff values for the reference range of PGa#C as the #C values reported in non-diabetic subjects.

Elevation of the renal threshold for glucose is associated with insulin resistance and higher glycated hemoglobin levels.

AIMS/INTRODUCTION: The renal threshold for glucose (RTg) corresponds to a blood glucose level of ~180 mg/dL; however, in hospitals, patients are often encountered who are hyperglycemic, but urine glucose test strip-negative, who remain negative for urine glucose even at blood glucose concentrations >180 mg/dL, implying a high RTg value. In this study, we aimed to identify factors determining high RTg in Japanese patients with type 2 diabetes mellitus. MATERIALS AND METHODS: We estimated RTg (eRTg) using urinalysis data from 67 type 2 diabetes mellitus patients for whom the glucose infusion rate (GIR) was determined by hyperinsulinemic-euglycemic clamp. After allocating patients to two groups according to their baseline eRTg (<180 mg/dL or ≥180 mg/dL), we identified the factors affecting eRTg using simple and multiple linear regression analyses. RESULTS: GIR, glycated hemoglobin (HbA1c), insulin use and dyslipidemia differed significantly between the groups. In simple regression analysis, GIR, HbA1c, body muscle-to-fat ratio and insulin use were significantly correlated with eRTg; and in multiple regression analysis, GIR and HbA1c remained independent negative and positive determinants, respectively, with the contribution of GIR being substantial. In receiver operating characteristic curve analysis, when GIR <5.7 was used as the insulin resistance threshold, the cut-off value of eRTg was 189 mg/dL (P = 0.0001). Furthermore, in receiver operating characteristic analysis using eRTg ≥189 mg/dL, the cut-off value for HbA1c was 8.0% (P = 0.0006). CONCLUSIONS: High eRTg is associated with low GIR and high HbA1c, with GIR making a substantial contribution.

HbA1c adjusted by erythrocyte creatine is a useful glycemic control indicator in patients with hemolysis.

OBJECTIVES: HbA1c shows low in patients with hemolysis, whereas glycated albumin (GA) is not affected by hemolysis. Therefore, the GA/HbA1c ratio reflects hemolysis in diabetic patients with hemolysis. Erythrocyte creatine (EC) is an indicator of hemolysis that reflects the mean erythrocyte age. The aim of this study was to examine whether HbA1c adjusted by EC accurately reflected glycemic control in patients with hemolysis. MATERIALS AND METHODS: A total of 238 individuals, consisting of 131 diabetic patients and 107 non-diabetic subjects, and consisting of 42 patients with hemolysis, and 196 subjects without hemolysis were selected for the study. HbA1c expressed in the IFCC units (iA1c) as well as in the NGSP units (A1C) were used. From the fact that EC and the GA/iA1c ratio showed a significant positive correlation, a formula for iA1c adjusted by EC (ECadj-iA1c) was created from a regression equation between EC and the GA/iA1c ratio. RESULTS: Significant correlations were observed between the GA/iA1c ratio and various hemolytic indicators but not between the GA/ECadj-iA1c ratio and those hemolytic indicators. The GA/iA1c ratio in individuals with hemolysis was significantly higher than in individuals without hemolysis, while no significant differences were observed in the GA/ECadj-iA1c ratio between the groups. Further, iA1c concentrations in non-diabetic patients with hemolysis were significantly lower than in the non-diabetic subjects without hemolysis, whereas ECadj-iA1c and GA concentrations showed no significant difference between the two groups. CONCLUSIONS: These results suggested that ECadj-iA1c accurately reflected glycemic control in patients with hemolysis.

Shortened mean erythrocyte age in female patients with type 2 diabetes mellitus.

BACKGROUND: The hyperglycemic state is known to shorten the erythrocyte life span. Erythrocyte creatine (EC) reflects the mean erythrocyte age and is useful as an indicator of hemolysis. Here, we studied the relationship between EC and glycemic control indicators [HbA1c or glycated albumin (GA)] in non-diabetic subjects and diabetic patients. METHODS: This study included 119 patients with type 2 diabetes mellitus (T2DM) and 76 non-diabetic subjects matched by sex and age. We studied the relationships between EC and HbA1c or GA in patients with T2DM and non-diabetic subjects. RESULTS: Erythrocyte creatine in T2DM patients was significantly higher than that in non-diabetic subjects, and the ratio of high EC levels (>1.8 µmol/g Hb) in T2DM patients was significantly higher as well. Furthermore, female EC was significantly higher than male EC, and the ratio of high EC levels in females was significantly higher than in the males as well. While male EC had no significant correlation with HbA1c or GA, female EC had significant positive correlations with both. Male EC had no significant difference between T2DM patients and non-diabetic subjects, while the EC in female patients with T2DM was significantly higher than in female non-diabetic subjects. CONCLUSIONS: The significant positive correlations of EC with HbA1c and GA in female patients with T2DM suggested that the mean erythrocyte age decreased in female diabetic patients with poor glycemic control.

Clinical usefulness of the body muscle-to-fat ratio for screening obstructive sleep apnea syndrome in patients with inadequately controlled type 2 diabetes mellitus.

AIMS: To investigate whether body composition measures can be used for screening obstructive sleep apnea syndrome (OSAS) in patients with type 2 diabetes mellitus (T2DM) suspected of having OSAS. METHODS: Subjects were 186 hospital inpatients with inadequately controlled T2DM. We measured the respiratory disturbance index (RDI) as an indicator of OSAS using a sheet-type breath detection monitor, defining OSAS as an RDI ≥ 19 events/hour. Elementary body composition was measured by bioelectrical impedance analysis using InBody770. RESULTS: Simple logistic regression analysis identified body weight, body mass index (BMI), waist circumference, total body fat mass, body fat percentage, and body muscle-to-fat ratio (BMFR) as significantly associated with OSAS. The Nagelkerke R2 test showed that the BMFR was the most suitable measure for screening OSAS. Multivariate logistic regression analysis demonstrated that BMFR was significantly and independently associated with OSAS. In receiver operating characteristic curve analysis, the area under the BMFR curve was 0.70 (P < 0.001), indicating that BMFR was significantly predictive of OSAS. Furthermore, BMFR was the most suitable measure for screening OSAS in a sub-group analysis of non-obese patients with relatively low BMI (<27.5 kg/m2). CONCLUSIONS: In patients with T2DM, the BMFR is useful for screening OSAS in daily clinical practice.