Comparison of serum fructosamine vs glycohemoglobin as measures of glycemic control in a large diabetic population

Fructosamine as a predictor of incident diabetic microvascular disease in a population with high prevalence of red cell disorders: A cohort study

AIMS

Fructosamine can be used to estimate glycaemia in individuals in whom HbA1c may be unreliable. We aimed to establish clinically useful fructosamine treatment targets in a population with a high prevalence of conditions affecting erythrocyte survival, including variant haemoglobin and G6PD deficiency.

METHODS

Fructosamine was measured on a clinical basis in individuals in whom HbA1c was suspected to be unreliable by their primary physician. Study endpoints were incident retinopathy and albuminuria in individuals with Prediabetes (n = 60), Type 1 (n = 161) or Type 2 diabetes (n = 1350) during follow up of 4.4 ± 2.3 years.

RESULTS

Fructosamine ≥ 250 umol/L was significantly associated with incident retinopathy, and fructosamine ≥ 300 umol/L with incident microalbuminuria, in univariate analysis and adjusted for established risk factors. Fructosamine ≥ 250 umol/L was also significantly associated with incident retinopathy in individuals with HbA1c < 7.0% (53 mmol/mol) at inclusion.

CONCLUSIONS

In this patient population, a single measurement of fructosamine significantly and independently predicts incident retinopathy in individuals with HbA1c < 7.0% (53 mmol/mol). Routine measurement of fructosamine on at least one occasion is recommended as part of assessment of prediabetes or diabetes mellitus in populations with a high prevalence of conditions affecting erythrocyte lifespan.

Trimester-Specific Serum Fructosamine in Association with Abdominal Adiposity, Insulin Resistance, and Inflammation in Healthy Pregnant Individuals

This study aimed to (1) characterize the variations in serum fructosamine across trimesters and according to pre-pregnancy BMI (ppBMI), and (2) examine associations between fructosamine and adiposity/metabolic markers (ppBMI, first-trimester adiposity, leptin, glucose homeostasis, and inflammation measurements) during pregnancy. Serum fructosamine, albumin, fasting glucose and insulin, leptin, adiponectin, interleukin-6 (IL-6), and C-reactive protein (CRP) concentrations were measured at each trimester. In the first trimester, subcutaneous (SAT) and visceral (VAT) adipose tissue thicknesses were estimated by ultrasound. In the 101 healthy pregnant individuals included (age: 32.2 ± 3.5 y.o.; ppBMI: 25.5 ± 5.5 kg/m2), fructosamine concentrations decreased during pregnancy whereas albumin-corrected fructosamine concentrations increased (p < 0.0001 for both). Notably, fructosamine concentrations were inversely associated with ppBMI, first-trimester SAT, VAT, and leptin (r = −0.55, r = −0.61, r = −0.48, r = −0.47, respectively; p < 0.0001 for all), first-trimester fasting insulin and HOMA-IR (r = −0.46, r = −0.46; p < 0.0001 for both), and first-trimester IL-6 (r = −0.38, p < 0.01). However, once corrected for albumin, most of the correlations lost strength. Once adjusted for ppBMI, fructosamine concentrations were positively associated with third-trimester fasting glucose and CRP (r = 0.24, r = 0.27; p < 0.05 for both). In conclusion, serum fructosamine is inversely associated with adiposity before and during pregnancy, with markers of glucose homeostasis and inflammation, but the latter associations are partially influenced by albumin concentrations and ppBMI.

Association of Glycated Proteins with Inflammatory Proteins and Periodontal Disease Parameters

Periodontitis is a chronic inflammatory condition that may contribute to diabetogenesis. The aim was to investigate the levels of glycated proteins and their correlation with periodontal and systemic inflammation. Fifty-one patients with periodontitis and 20 healthy subjects underwent probing pocket depth (PPD) measurements. PPD total and PPD disease with and without tooth adjustment were used as continuous indices. Marginal bone loss (MBL) for mandibular premolars and molars was measured digitally. Body mass index (BMI) and waist circumference (WC) were also analyzed. Glycated hemoglobin (HbA1c) and fructosamine (FrAm) levels were measured in all subjects. A multiplex proximity extension assay (PEA) was used to analyze the serum samples for simultaneous measurement of 92 proteins. Both HbA1c and FrAm inversely correlated with IL-10, FGF-21, MCP-1, and TNF beta amongst 16 proteins. HbA1c correlated directly with OPG. Parameters of disease severity were consistently significant for HbA1c. Adjusted PPD total and number of missing teeth were increased in diabetes whereas levels of RANKL and RANKL to OPG ratio were the highest in nondiabetic periodontitis patients. Hyperglycemic conditions in periodontitis patients are associated with reduced levels of anti-inflammatory proteins as well as dysregulated bone resorption.

Efficacy, safety and acceptability of the new pen needle 34G × 3.5 mm: a crossover randomized non-inferiority trial; AGO 02 study

OBJECTIVE

Insulin injection aspects, such as fear of injection and pain, directly affect glycemic control, patient adherence and quality of life. Use of thinner and shorter needles could increase acceptance of injections. The aim of the study is to evaluate the non-inferiority of the new 34G × 3.5 mm needle compared to a 32G × 4 mm in patients with diabetes treated with insulin.

METHODS

This is an open, randomized, two-period crossover, non-inferiority trial. Every treatment period lasted 3 weeks. Patients with type 1 or type 2 diabetes, treated with multiple daily insulin injections, were randomly assigned to receive a 34G × 3.5 mm or a 32G × 4 mm pen needle. The primary endpoint was the non-inferiority of the 34G × 3.5 mm in comparison with the 32G × 4 mm pen needle in terms of percentage absolute change of blood fructosamine (% |ΔFru|), using a non-inferiority margin of 20%.

RESULTS

Overall 77 patients were randomized and 73 completed the study. Patients characteristics were: 52% male, 80.5% affected by type 1 diabetes, mean age 52 years (±14.6), mean BMI 24.5 kg/m² (±5.6), HbA1c 8% (±1.1) and baseline fructosamine level 350 µmol/l (±84). Mean fructosamine levels increased by 0.56 µmol/l with the 34G needle, while a reduction of 7.29 μmol/l was documented with the 32G needle. The difference between the two groups (7.84 μmol/l) was not statistically significant (p = .27). The % |ΔFru| between the two groups was 7.55% (95% CI 5.67-9.44), meeting the non-inferiority criterion. Glycemic variability, expressed as standard deviation of fasting blood glucose and post-prandial glucose, was not different between the two treatment groups (p = .63 and p = .77, respectively).

CONCLUSIONS

The 34G × 3.5 mm needle was non-inferior to the 32G × 4 mm needle regarding fructosamine levels and glycemic variability supporting the suitability of the 34G × 3.5 mm needle for insulin injection in patients with diabetes.

CLINICAL TRIAL REGISTRATION

NCT02690467.

Glycosylation Gap in Patients with Diabetes with Chronic Kidney Disease and Healthy Participants: A Comparative Study

AIM

The aim of this study it to determine the level of glycosylation gap in patients with type 2 diabetes and its relation with kidney dysfunction.

MATERIALS AND METHODS

In this study, 150 individuals were enrolled (aged 20-75 year) and divided into three groups. Group 1 included 50 nondiabetic individuals who served as control. Group 2 included 50 patients with type 2 diabetes without chronic kidney disease (CKD), and in Group 3, there were 50 patients with type 2 diabetes with CKD. Glycated hemoglobin (HbA1c) and fructosamine (FA) were measured in all groups to determine the glycosylation gap (GG), predicted HbA1c, and mean blood glucose (MBG). GG is defined as the difference between measured HbA1c and HbA1c predicted from FA based on the population regression of HbA1c on FA. The variables were compared by correlation analysis.

RESULTS

Serum creatinine level was significantly high in patients with CKD (1.93 ± 0.99) as compared to patients with diabetes and control (0.891 ± 0.16; 0.912 ± 0.1), respectively. The study demonstrated a significant elevation in serum FA, measured HbA1c and predicted HbA1c, MBG in patients with diabetes with CKD as compared with those of without CKD, and controls. GG was found in healthy control (0.51 ± 0.78), patients with type 2 diabetes without CKD (0.62 ± 0.45), and patients with diabetes with CKD (1.0 ± 0.91), respectively.

CONCLUSION

It is concluded that GG may be a useful clinical research tool for evaluating pathological source of variation in diabetes complications such as kidney disease.

Efficacy, safety and acceptability of the new pen needle 33G × 4 mm. AGO 01 study

OBJECTIVES

Adherence to insulin therapy can be threatened by pain and needle fear. This cross-over randomized non-inferiority trial evaluated a new Pic Insupen 33G × 4 mm needle vs. a 32G × 4 mm needle in terms of metabolic control, safety and acceptability in patients with diabetes treated with insulin.

RESEARCH DESIGN AND METHODS

We used a centralized, permuted block randomization, stratified by center and maximum insulin dose per single injection. Subjects used the two needles in two 3 week treatment periods. The primary endpoint was the absolute percentage variation of the blood fructosamine between the two treatments (% |ΔFru|). Additional endpoints were: glycemic variability, total insulin doses, body weight, severe hypoglycemic episodes, leakage at injection sites and pain measured by visual analogue scale. Equivalent glycemic control was defined a priori as % |ΔFru| (including 95% CI) within 20%.

RESULTS

Of 87 subjects randomized, 77 completed the study (median age 53.1 [IR 42.3-61.2], median BMI 24.3 Kg/m(2) [IR 21.3-28.5], median duration of insulin therapy [in months] 141.4 (IR 56.3-256.9), median baseline HbA1c 7.9% [IR 7.2-8.8]). The % |ΔFru| was 7.93% (95% CI 6.23-9.63), meeting the non-inferiority criterion. The fasting blood glucose standard deviation was 46.2 (mean 154.6) with the 33G needle and 42.8 (mean 157.3) with the 32G needle (p=0.42). Insulin daily dose and patients' weight did not show any statistically significant variation. We observed 95 episodes of symptomatic hypoglycemia with the 33G needle and 96 with the 32G needle. One episode of severe hypoglycemia was documented in the latter group. As for insulin leakage we observed 37.55 episodes per 100 patient-days with the 33G needle and 32.21 episodes per 100 patient-days with the 32G needle (p=0.31). Patients reported less pain with the 33G × 4 mm needle (p=0.05).

STUDY LIMITATIONS

Study sample was mainly composed of adults with type 1 diabetes and study was not blinded.

CONCLUSIONS

The 33G needle is not inferior to the 32G needle in terms of efficacy and safety, with reduced pain and no difference in insulin leakage.

CLINICAL TRIAL REGISTRATION

NCT01745549.

Defining a therapeutic window for laser irradiation (810 nm) applied to the inguinal region to ameliorate diabetes in diabetic mice

OBJECTIVE

The purpose of this study was to determine a therapeutic window of antidiabetic effect by laser irradiating the left inguinal region of diabetic mice (810 nm 20.4 and 40.8 J/cm(2)) for 7 days.

BACKGROUND DATA

Irradiation of 810 nm 10.2 J/cm(2) to the left inguinal region of diabetic mice for 7 days significantly decreased blood plasma fructosamine compared with nonirradiated controls.

METHODS

Forty-seven diabetic mice were used. Body weight and water intake of the mice were measured daily for 7 days prior to start of treatment (day 0). Mice were irradiated on the left inguinal region with 810 nm laser 20.4 J/cm(2) (n=15) or 40.8 J/cm(2) (n=15) for 7 days, or were not irradiated (control, n=17). Body weight and water intake were measured to day 7. On day 7, mice were fasted for 5 h, anesthetized with sodium pentobarbitone (i.p.), and blood plasma was collected. The blood plasma was assayed for glucose and fructosamine.

RESULTS

Water intake was significantly increased on day 7 compared with day 0 for diabetic mice receiving laser treatment. Blood plasma glucose levels on day 7 for diabetic mice irradiated 20.4 and 40.8 J/cm(2) were not significantly different than for nonirradiated controls. The blood plasma fructosamine level of diabetic mice irradiated with 20.4 J/cm(2) was significantly lower than for nonirradiated controls, whereas that for diabetic mice irradiated with 40.8 J/cm(2) was not significantly different than for nonirradiated controls.

CONCLUSIONS

Irradiation (810 nm laser 10.2-20.4 J/cm(2)) to the left inguinal region of diabetic mice for 7 days has the potential to ameliorate diabetes, as is shown by decreased blood plasma fructosamine.

Raman spectroscopy provides a powerful diagnostic tool for accurate determination of albumin glycation

We present the first demonstration of glycated albumin detection and quantification using Raman spectroscopy without the addition of reagents. Glycated albumin is an important marker for monitoring the long-term glycemic history of diabetics, especially as its concentrations, in contrast to glycated hemoglobin levels, are unaffected by changes in erythrocyte life times. Clinically, glycated albumin concentrations show a strong correlation with the development of serious diabetes complications including nephropathy and retinopathy. In this article, we propose and evaluate the efficacy of Raman spectroscopy for determination of this important analyte. By utilizing the pre-concentration obtained through drop-coating deposition, we show that glycation of albumin leads to subtle, but consistent, changes in vibrational features, which with the help of multivariate classification techniques can be used to discriminate glycated albumin from the unglycated variant with 100% accuracy. Moreover, we demonstrate that the calibration model developed on the glycated albumin spectral dataset shows high predictive power, even at substantially lower concentrations than those typically encountered in clinical practice. In fact, the limit of detection for glycated albumin measurements is calculated to be approximately four times lower than its minimum physiological concentration. Importantly, in relation to the existing detection methods for glycated albumin, the proposed method is also completely reagent-free, requires barely any sample preparation and has the potential for simultaneous determination of glycated hemoglobin levels as well. Given these key advantages, we believe that the proposed approach can provide a uniquely powerful tool for quantification of glycation status of proteins in biopharmaceutical development as well as for glycemic marker determination in routine clinical diagnostics in the future.

Laser photostimulation (660 nm) of wound healing in diabetic mice is not brought about by ameliorating diabetes

BACKGROUND AND OBJECTIVES

We have used a 660-nm laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). It is possible that the stimulation of healing could be due to possible diabetes-modifying properties of laser light. This has been examined by using the 660 nm laser to irradiate non-wounded diabetic mice with the same dose and at same location as for wounded diabetic mice.

MATERIALS AND METHODS

Twenty-two diabetic mice were used and divided into two equal groups. Body weight and water intake of mice were measured daily for 7 days prior to the start of treatment (Day 0). The left flank of mice in the experimental group was irradiated with 660 nm laser, 100 mW, 20 seconds/day, 7 days; for mice in the control group, the left flank was sham-treated with the laser power supply not switched on. Body weight and water intake of mice were measured to Day 14. On Day 14, the mice were fasted for 4 hours, anaesthetized with sodium pentobarbitone (i.p.) and blood collected by cardiac puncture into heparinized tubes. The plasma was assayed for glucose and glycated hemoglobin A1c.

RESULTS

There were no significant differences in body weight and water intake over 22 days between mice in the experimental group and control group. On day 14, the mean blood plasma glucose level was not significantly different between the two groups; glycated hemoglobin A1c was not detected in the samples.

CONCLUSION

Irradiation of the left flank in diabetic mice with 660 nm laser system does not have a significant hypoglycemic effect, and the laser-stimulated healing of wounds in diabetic mice is due to cellular and biochemical changes in the immediate wound environment.

Evaluation of the serum fructosamine test to monitor plasma glucose concentration in the late-pregnant sheep

Since the persistent decrease in blood glucose during late pregnancy in sheep is an index of high risk of metabolic disorder, the present study aimed to evaluate the capacity of the serum fructosamine (Fser) to retrospectively monitor blood glucose. Pregnant grazing sheep were assigned to three treatments: high energy (n = 8), supplemented with 400 g of corn grain from Day 100 until lambing; medium energy (n = 7), not supplemented, and low energy (n = 8), fasted from Days 136 to 141. In weekly blood samples (7 weeks before to 3 weeks after lambing), glucose, fructosamine, β-hydroxybutyrate and total proteins were determined. Serum protein were stable and without differences among groups. β-hydroxybutyrate was higher in the fasted group the week after fasting (P < 0.05). The regression analysis between plasma glucose and Fser in the same week and in the 3 weeks following, showed no significant correlations, actual or retrospective, neither considering all sheep nor within each energy level. The results did not support the usefulness of Fser for monitoring plasma glucose concentration in late pregnant ewes.

Effect of diabetes on enzymes involved in rat hepatic corticosterone production

BACKGROUND

Numerous studies have explored the etiologic or permissive role of 11β-hydroxysteroid dehydrogenase (11β-HSD1) in obesity and Type 2 diabetes, biochemical conditions often with concurrent hyperinsulinism. In contrast, there are limited data on the effect of insulin deficiency (i.e. Type 1 diabetes) on 11β-HSD1 or endoplasmic reticulum enzymes that generate the reduced pyridine cofactor NADPH. Thus, the aim of the present study was to examine the effect of insulin-deficient, streptozotozin diabetes on key microsomal enzymes involved in rat hepatic corticosterone production.

METHODS

After rats had been rendered diabetic with streptozotocin and some had been treated with insulin (2-6 units, s.c., long-acting insulin once daily) for 7 days, hepatic microsomes were isolated. Serum corticosterone and fructosamine were obtained premortem. Intact microsomes were incubated in vitro and 11β-HSD1, hexose-6-phosphate dehydrogenase (H6PDH), and isocitrate dehydrogenase (IDH) measured.

RESULTS

Although diabetes markedly altered body weight gain and serum protein glycosylation (assessed by fructosamine), there was no significant change in hepatic 11β-HSD1 reductase activity, with or without insulin treatment. However, serum corticosterone levels were significantly correlated with 11β-HSD1 reductase activity when all groups were analyzed together (P < 0.05). Untreated diabetes modified (P < 0.01) two hepatic microsomal NADPH-generating enzymes, namely H6PDH and IDH, resulting in a 37% decrease and 14% increase in enzyme levels, respectively.

CONCLUSIONS

Consistent with most in vivo studies, chronic insulin deficiency with attendant hyperglycemia does not significantly modify hepatic 11β-HSD1 reductase activity, but does alter the activity of two microsomal enzymes coupled with pyridine cofactors.

Comparative glycemic control, safety and patient ratings for a new 4 mm x 32G insulin pen needle in adults with diabetes

OBJECTIVE

Pen needles (PN) for subcutaneous insulin therapy have become smaller; 5 mm PNs are now the shortest in use. We evaluated the safety, efficacy and patient ratings of a new 4 mm x 32 gauge (G) PN.

RESEARCH DESIGN AND METHODS

Subjects with type 1 and type 2 diabetes and HbA1c 5.5% to 9.5% participated in a randomized non-inferiority cross-over trial, at four U.S. centers. Subjects used 4 mm x 32G PNs and either 5 mm x 31G PNs (4/5 mm) or 8 mm x 31G PNs (4/8 mm) in two, 3-week treatment periods; order of needle use was controlled. Subjects were either 'low dose' or 'regular dose' users (highest single insulin dose <or= 20 units and 21-40 units, respectively). Percent absolute change in serum fructosamine (% |Delta Fru|) was the primary endpoint; unexplained, severe hypo- or hyperglycemia was a secondary measure. Leakage at injection sites and pain measured by visual analog scale were tertiary measures. Equivalent glycemic control was defined á priori as % |Delta Fru| (including 95% CI) within 20%; 40 subjects per subgroup provides 90% power at alpha = 0.05.

CLINICAL TRIAL REGISTRATION

The study was registered on clinicaltrials.gov (identifier: NCT00928057).

RESULTS

Of 173 subjects randomized, 168 completed the study, and 163 were included in the fructosamine analyses--83 and 80 in the 4/5 mm and 4/8 mm groups, respectively. Subjects were 56% male, mean 52.6 yrs, 63% type 2. Baseline HbA1c = 7.5 +/- 1.0% and fructosamine 301 +/- 55.1 micromol/L. Mean % |Delta Fru| was 4.9% (95% CI 3.8, 6.0) and 5.5% (4.5, 6.4), respectively, for the 4/5 mm and 4/8 mm groups, meeting glycemic equivalence criteria; results were similar in both dose groups. The median |Delta Fru| was 11.0 micromol/L (8.0, 13.0) and 13.5 micromol/L (9.8, 18.0) for the 4/5 mm and 4/8 mm groups, respectively. Unexplained, severe hypo- and hyperglycemic episodes were infrequent and not different between PNs. The 4 mm PN was rated significantly less painful and preferred by approximately 2/3 of subjects (p < 0.01). All three PNs had similar reported injection site leakage.

LIMITATIONS

The study was of relatively short duration, in adults in the U.S. Further trials in other patients (e.g., GLP-1 users, pediatrics, obese) should be performed.

CONCLUSIONS

The 4 mm x 32G PN provided equivalent glycemic control compared to 31G, 5 mm and 8 mm PNs with reduced pain, no difference in insulin leakage and was preferred by patients.

A novel method for the determination of 1,5-anhydroglucitol, a glycemic marker, in human urine utilizing hydrophilic interaction liquid chromatography/MS(3)

Plasma levels of 1,5-anhydroglucitol (1-deoxyglucose), a short-term marker of glycemic control, have been measured and used clinically in Japan since the early 1990s. Plasma levels of 1,5-anhydroglucitol are typically measured using either a commercially available enzymatic kit or GC/MS. A more sensitive method is needed for the analysis of 1,5-anhydroglucitol in urine, where levels are significantly lower than in plasma. We have developed a sensitive and selective LC/MS(3) assay utilizing hydrophilic interaction liquid chromatography and ion trap mass spectrometry for the quantitative determination of 1,5-anhydroglucitol in human urine. Diluted human urine samples were analyzed by LC/MS(3) using an APCI source operated in the negative ionization mode. Use of an ion trap allowed monitoring of MS(3) transitions for both 1,5-anhydroglucitol and the internal standard which provided sufficient selectivity and sensitivity for analysis from 50 microL of human urine. Quantitation of 1,5-anhydroglucitol levels in urine was accomplished using a calibration curve generated in water (calibration range 50 ng/mL to 10 microg/mL). Method ruggedness and reproducibility were evaluated by determining the intra- and inter-day accuracies and precision of the assay, as well as the bench-top and freeze-thaw stability. For both inter- and intra-assay evaluations, the accuracy of the assay was found to be acceptable, with the concentrations of all QCs tested not deviating more than 8% from theoretical. Four-hour bench-top and freeze-thaw stabilities were also evaluated; 1,5-anhydroglucitol was found to be stable at room temperature (<18% deviation from theoretical) and during 3 freeze-thaw cycles (<1% deviation from theoretical, except at the lowest QC level). The LC/MS(3) assay was then used to successfully determine the concentration of 1,5-AG in more than 200 urine samples from diabetic patients enrolled in a clinical study.

1,5-anhydroglucitol (GlycoMark) as a marker of short-term glycemic control and glycemic excursions

1,5-anhydroglucitol (1,5-AG) is a validated marker of short-term glycemic control. It is a metabolically inert polyol that competes with glucose for reabsorption in the kidneys. Otherwise stable levels of 1,5-AG are rapidly depleted as blood glucose levels exceed the renal threshold for glucosuria. 1,5-AG more accurately predicts rapid changes in glycemia than hemoglobin A1C (A1C) or fructosamine. It is also more tightly associated with glucose fluctuations and postprandial glucose. Thus, 1,5-AG may offer complementary information to A1C. This review will summarize the limitations of current methods of assessing glycemic control, assess the data to support 1,5-AG as a glycemic marker and highlight the scenarios by which 1,5-AG may fill the gap in assessing glycemic control.

Paired values of serum fructosamine and blood glucose for the screening of gestational diabetes mellitus: A retrospective study of 165 Saudi pregnant women

This study reports the utilization of serum fructosamine and blood glucose for the screening of gestational diabetes mellitus (GDM). Blood samples from 165 pregnant women were analyzed for fasting blood glucose (FBG), random blood glucose (RBG) and serum fructosamine. The actual fructosamine levels were corrected for serum protein (c-Fruct) for more precise presentation. Two cut-off values of FBG (>5.3 mmol/L and >7.0 mmol/L) and RBG (>7.8 mmol/L and >11.0 mmol/L) were used to classify hyperglycemic subjects for subsequent evaluation. The average values±standard deviations for FBG, RBG and cFruct were 5.865±1.95, 7.767±3.21 and 2.387±0.47 mmol/L, respectively. FBG levels were significantly correlated with RBG (Pearson correlation=0.597, P<0.001). Significant correlations were also observed between cFruct and FBG (Pearson correlation=0.673, P<0.001) or RBG (Pearson correlation=0.641, P<0.001). Out of 165 subjects, 24 (14.5%) cases were classified as hyperglycemic on the basis of FBG>7.0 mmol/L or RBG>11.0 mmol/L; use of lower cut-off values resulted higher frequencies of hyperglycemia. Whereas, a combined criteria of FBG>5.3 mmol/L and cFruct >2.5 mmol/L predicted 35 patients as the most probable hyperglycemic as compared to 32 patients identified using the criteria of RBG >7.8 mmol/L and cFruct >2.5 mmol/L. These criteria were associated with 4.8% and 3.6% false-positivity at the expense of 3.6% and 3.0% false-negative outcomes, respectively. The levels of FBG, RBG and cFruct were significantly higher in hyperglycemic groups (irrespective of grouping criteria) as compared to the respective normal groups. In conclusion, these findings clearly indicate that the paired values of cFruct with FBG or RBG could help in filtering high-risk individuals for OGTT and therefore avoiding a unnecessary OGTT.

Importance of measuring products of non-enzymatic glycation of proteins

Non-enzymatic glycation products are a complex and heterogeneous group of compounds which accumulate in plasma and tissues in diabetes and renal failure. There is emerging evidence that these compounds may play a role in the pathogenesis of chronic complications associated with diabetes and renal failure. So measurement of the products of non-enzymatic glycation has a twofold meaning: on one hand, measurement of early glycation products can estimate the extent of exposure to glucose and the subject's previous metabolic control; on the other hand, measurement of intermediate and late products of the glycation reaction is a precious instrument in verifying the relationship between glycation products and tissue modifications. This review summarizes current knowledge about the diagnostic utility of measuring non-enzymatic glycation products.

Serum 1,5-anhydroglucitol (GlycoMark ): a short-term glycemic marker

1,5-Anhydroglucitol (1,5-AG), the 1-deoxy form of glucose, has been measured and used clinically in Japan for over a decade to monitor short-term glycemic control. Evaluation of glucose control otherwise requires measuring plasma glucose or glycated proteins whose levels reflect average glucose concentration over the half-life of the protein analyzed. Hemoglobin A1c measurements reflect blood glucose levels over that past 2-3 months, while fructosamine can be used to evaluate glycemic control over 10-14 days. In contrast, 1,5-AG levels in blood respond within 24 h as a result of glucose's competitive inhibition of 1,5-AG reabsorption in the kidney tubule. When glucose levels rise, even transiently, urinary loss of 1,5-AG occurs, and circulating levels fall. Because of changes in renal hemodynamics in normal pregnancies, 1,5-AG appears of limited usefulness in evaluation of gestational diabetes. However, the characteristics of 1,5-AG levels in patients with moderate to near-normal glycemic control suggest that it may be a valuable complement to frequent self-monitoring or continuous monitoring of plasma glucose to confirm stable glycemic control. Measurements performed daily or weekly in a given patient would suggest that overall glycemic control has been stable or improved if 1,5-AG levels are stable or increasing. If 1,5-AG levels fall, greater attention to glucose monitoring and both lifestyle and medical management could be prescribed to correct the glycemic excursions that would underlie such changes. The behavior of this analyte is different from all others used in the management of diabetes, creating potential opportunities for its use in clinical practice.

Discordance between HbA1c and fructosamine: evidence for a glycosylation gap and its relation to diabetic nephropathy

OBJECTIVE

Discordances between HbA1c and other measures of glycemic control are common in clinical practice and remain unexplained. We developed a measure of discordance between HbA1c and fructosamine (FA) (glycosylated serum proteins) to conduct a systematic evaluation. We termed this the glycosylation gap (GG) and sought to determine its relationship to diabetic nephropathy.

RESEARCH DESIGN AND METHODS

Measurements of HbA1c and FA on the same sample in 153 people were used to calculate GG, defined as the difference between measured HbA1c and HbA1c predicted from FA based on the population regression of HbA1c on FA.

RESULTS

GG had a broad distribution (range, -3.2% to 5.5%); 40% of samples had values indicating major differences in prediction of complications risk by the measured versus predicted HbA1c. GG was highly correlated (r = 0.81) between measurements repeated in 65 patients 23 +/- 2 weeks apart, indicating that the discordances are reliable and not explained by differences in turnover of underlying proteins. In 40 patients with type 1 diabetes of >or = 15 years' duration, an increase in GG by 1% was associated with a 2.9-fold greater frequency of increasing nephropathy stage (P = 0.0014). GG was -0.8 +/- 0.2% in subjects with no nephropathy, -0.3 +/- 0.2% with microalbuminuria/hypertension, and 0.7 +/- 0.3% in subjects with proteinuria or renal dysfunction (P < 0.05). GG correlated better with nephropathy than did either HbA1c or FA alone in this population.

CONCLUSIONS

The glycosylation gap may be a useful clinical research tool for evaluating physiologic sources of variation in diabetic complications beyond glycemic control.

Considerations on blood glucose management in Type 2 diabetes mellitus

In recent years the benefits of more intensive management in preventing or delaying the development and progression of diabetic complications have been well documented. What is not as well documented is how to motivate the person with diabetes to manage the condition, how to set, assess and quantify glucose goals, and the glucose variables that should be routinely measured. This review discusses the importance of setting targets and communicating them in a way that the patient understands. When aiming for a glycaemia target, balance is required (1) between achieving reduction of complications and causing an increased degree of hypoglycaemia, and (2) between what is achievable and what degree of benefit is gained. Target values given in guidelines should be adapted by the clinician to take into account the patient's susceptibility to hypoglycaemia, stage and type of complications, age and life expectancy, co-morbidity, social environment, understanding of the steps required and level of commitment to the treatment. Several suggestions are given regarding possible improvements and amendments to existing guidelines for diabetes management in treating to glucose goal. For example, attention should be drawn to the need to individualize goals and to consider education, long-term support, patient needs and treatment outcome when formulating diabetes management plans. The relative properties of the different glucose variables-fasting plasma glucose (FPG), postprandial plasma glucose (PPG), glycated haemoglobin A(1c) (HbA(1c)), and glycated protein-in terms of their convenience of measurement, usefulness and relevance to the physician and patient are also evaluated. When prioritising the variables to be measured it is suggested that where feasible, HbA(1c) should be the standard measurement by which to gauge risk and treatment efficacy. Serial measurements should be made and, where possible, the use of blood glucose meters encouraged, in order to obtain a blood glucose profile for the patient.

New OTC drugs and devices 1999: a selective review

OBJECTIVES

To educate pharmacists about newly introduced nonprescription products/devices/diagnostic products, and to create a heightened awareness of the dilemma of dietary supplements and the problems their use poses for consumers and pharmacists.

DATA SOURCES

Recent clinical and pharmaceutical industry literature.

DATA SYNTHESIS

It is critical for the pharmacist to be knowledgeable about dietary supplements to be able to appropriately counsel patients on benefits and risks associated with their use. In addition, numerous other nonprescription products, including home diagnostic products and accessories, will continue to become available on the U.S. market. It is important that the pharmacist become as knowledgeable as possible about these and be capable of educating the consuming public about their appropriate use.

CONCLUSION

Dietary supplements will continue to flood the self-care market. Pharmacists need a balanced understanding of these products to assist the consumer. The new nonprescription medications cited in this review represent valuable additions to the growing array of self-care products for consumer use.