Circulating biomarkers of glycemia in diabetes management and implications for personalized medicine

Circulatory Metabolite Ratios as Indicators of Lifestyle Risk Factors Based on a Greek NAFLD Case-Control Study

An ensemble of confounding factors, such as an unhealthy diet, obesity, physical inactivity, and smoking, have been linked to a lifestyle that increases one's susceptibility to chronic diseases and early mortality. The circulatory metabolome may provide a rational means of pinpointing the advent of metabolite variations that reflect an adherence to a lifestyle and are associated with the occurrence of chronic diseases. Data related to four major modifiable lifestyle factors, including adherence to the Mediterranean diet (estimated on MedDietScore), body mass index (BMI), smoking, and physical activity level (PAL), were used to create the lifestyle risk score (LS). The LS was further categorized into four groups, where a higher score group indicates a less healthy lifestyle. Drawing on this, we analyzed 223 NMR serum spectra, 89 MASLD patients and 134 controls; these were coupled to chemometrics to identify "key" features and understand the biological processes involved in specific lifestyles. The unsupervised analysis verified that lifestyle was the factor influencing the samples' differentiation, while the supervised analysis highlighted metabolic signatures. Τhe metabolic ratios of alanine/formic acid and leucine/formic acid, with AUROC > 0.8, may constitute discriminant indexes of lifestyle. On these grounds, this research contributed to understanding the impact of lifestyle on the circulatory metabolome and highlighted "prudent lifestyle" biomarkers.

The relationship between plasma lipids, oxidant-antioxidant status, and glycated proteins in individuals at risk for atherosclerosis

Objective: Ageing is one of the major risks for atherosclerosis. The age-related changes of interactions between plasma lipids, oxidative stress, antioxidant defense, and glycation processes are still not established while we age. Thus, the aim of the study was to analyze such relationships in individuals at risk for atherosclerosis due to their age.

Methods: Elderly and middle-aged persons with no acute disease or severe chronic disorder were assessed. Fasting plasma lipids (total cholesterol (T-C), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol, and triacylglycerols), thiobarbituric acid reacting substances (TBARS), plasma total antioxidant status (TAS), and glucose and glycated proteins (fructosamine (FA) and glycated hemoglobin (HbA_1c)) were determined. An oral glucose tolerance test allowed exclusion of persons with type 2 diabetes.

Results: Lipid profiles were significantly profitable, increased HDL-C especially (p<0.0001), in the elderly versus middle-aged group. Decreased TBARS and TAS were found in the elderly versus middle-aged group (p=0.0001 and p=0.00002, respectively). Increased fructosamine was found in the elderly (255±30 μmol/L) versus middle-aged (236±33 μmol/L) group (p=0.006). Multiple regression analysis showed that in the middle-aged group TBARS correlated with T-C and HDL-C, and in the elderly group with HbA_1c and FA independently of other factors.

Conclusion: The factors which have an impact on oxidant–antioxidant status are crucial to understanding the pathomechanisms of senescence as well as the development of chronic diseases. Healthy aging may be maintained throughout proper lipid control. Moreover, data support the premise that the balance between lipid metabolism and oxidative stress may play a role in the initial phases of glycation plasma proteins particularly among elderly persons.

Claimed effects, outcome variables and methods of measurement for health claims proposed under European Community Regulation 1924/2006 in the area of blood glucose and insulin concentrations

Most requests for authorization to bear health claims under Articles 13(5) and 14 related to blood glucose and insulin concentration/regulation presented to the European Food Safety Authority (EFSA) receive a negative opinion. Reasons for such decisions are mainly ascribable to poor substantiation of the claimed effects. In this scenario, a project was carried out aiming at critically analysing the outcome variables (OVs) and methods of measurement (MMs) to be used to substantiate health claims, with the final purpose to improve the quality of applications provided by stakeholders to EFSA. This manuscript provides a position statement of the experts involved in the project, reporting the results of an investigation aimed to collect, collate and critically analyse the information relevant to claimed effects (CEs), OVs and MMs related to blood glucose and insulin levels and homoeostasis compliant with Regulation 1924/2006. The critical analysis of OVs and MMs was performed with the aid of the pertinent scientific literature and was aimed at defining their appropriateness (alone or in combination with others) to support a specific CE. The results can be used to properly select OVs and MMs in a randomized controlled trial, for an effective substantiation of the claims, using the reference method(s) whenever available. Moreover, results can help EFSA in updating the guidance for the scientific requirements of health claims.

Effect of restricted feeding under rearing on reproduction, body condition and blood metabolites of rabbit does selected for growth rate

Young rabbit females selected for growth rate can have nutritional needs which may not be met by the common practice of feed restriction during rearing in commercial rabbit production. The aim of this study was to analyse the effect of two different feeding programmes: restricted and ad libitum feeding, applied in young rabbit females for one month at the end of rearing, on reproductive performance, body condition and circulating metabolic hormones and metabolites in a rabbit line selected by growth rate in 3 consecutive reproductive cycles. Thus, twenty-four 16-week-old does were randomly assigned to a group in which the daily recommended nutrient intakes were satisfied (fed restricted: 130 g/day, n=13) or a group fed to satiety (ad libitum: 235.5 g/day, n=11) during one month. Then, all does were inseminated in 3 consecutive cycles using a 42-day reproductive cycle. Measurements of does’ body weight, perirenal fat thickness and plasma leptin, non-esterified-fatty-acids (NEFA), beta-hydroxybutyrate (BOHB) and fructosamine were performed at artificial insemination (AI), parturition and weaning time in 3 consecutive cycles. Reproductive performance of does was evaluated based on fertility, litter size at parturition, prolificacy and productivity. Differences in body weight were found only in the 1^st cycle, ad libitum fed females being heavier than restricted ones. Nevertheless, body weight variances disappeared in later cycles. No differences were found in perirenal fat thickness. Finally, in ad libitum fed females slight differences were found in plasma levels of NEFAs (452 vs. 258 μekv/L and 527 vs. 306 μekv/L for 1^st and 2^nd cycles) and BOHB (0.26 vs. 0.03 mM for 2^nd cycle), but disappeared in the 3^rd reproductive cycle. Fertility, prolificacy and productivity was not significantly affected by the feeding programme. Nevertheless, total litter size showed to be higher in ad libitum fed females at second parturition (8.7 vs. 5.9 kits). Therefore, the evaluated feeding programmes until first AI in females selected by growth rate had no effect on their reproductive outcomes, as the global reproductive performance was not affected.

Metabolic serum biomarkers for the prediction of cancer: a follow-up of the studies conducted in the Swedish AMORIS study

The Swedish Apolipoprotein MOrtality RISk study (AMORIS) contains information on more than 500 biomarkers collected from 397,443 men and 414,630 women from the greater Stockholm area during the period 1985–1996. Using a ten-digit personal identification code, this database has been linked to Swedish national registries, which provide data on socioeconomic status, vital status, cancer diagnosis, comorbidity, and emigration. Within AMORIS, 18 studies assessing risk of overall and site-specific cancers have been published, utilising a range of serum markers representing glucose and lipid metabolism, immune system, iron metabolism, liver metabolism, and bone metabolism. This review briefly summarises these findings in relation to more recently published studies and provides an overview of where we are today and the challenges of observational studies when studying cancer risk prediction.

Overall, more recent observational studies supported previous findings obtained in AMORIS, although no new results have been reported for serum fructosamine and inorganic phosphate with respect to cancer risk. A drawback of using serum markers in predicting cancer risk is the potential fluctuations following other pathological conditions, resulting in non-specificity and imprecision of associations observed. Utilisation of multiple combination markers may provide more specificity, as well as give us repeated instead of single measurements. Associations with other diseases may also necessitate further analytical strategies addressing effects of serum markers on competing events in addition to cancer. Finally, delineating the role of serum metabolic markers may generate valuable information to complement emerging clinical studies on preventive effects of drugs and supplements targeting metabolic disorders against cancer.

The Shepherds' Tale: A Genome-Wide Study across 9 Dog Breeds Implicates Two Loci in the Regulation of Fructosamine Serum Concentration in Belgian Shepherds

Diabetes mellitus is a serious health problem in both dogs and humans. Certain dog breeds show high prevalence of the disease, whereas other breeds are at low risk. Fructosamine and glycated haemoglobin (HbA1c) are two major biomarkers of glycaemia, where serum concentrations reflect glucose turnover over the past few weeks to months. In this study, we searched for genetic factors influencing variation in serum fructosamine concentration in healthy dogs using data from nine dog breeds. Considering all breeds together, we did not find any genome-wide significant associations to fructosamine serum concentration. However, by performing breed-specific analyses we revealed an association on chromosome 3 (pcorrected ≈ 1:68 × 10-6) in Belgian shepherd dogs of the Malinois subtype. The associated region and its close neighbourhood harbours interesting candidate genes such as LETM1 and GAPDH that are important in glucose metabolism and have previously been implicated in the aetiology of diabetes mellitus. To further explore the genetics of this breed specificity, we screened the genome for reduced heterozygosity stretches private to the Belgian shepherd breed. This revealed a region with reduced heterozygosity that shows a statistically significant interaction (p = 0.025) with the association region on chromosome 3. This region also harbours some interesting candidate genes and regulatory regions but the exact mechanisms underlying the interaction are still unknown. Nevertheless, this finding provides a plausible explanation for breed-specific genetic effects for complex traits in dogs. Shepherd breeds are at low risk of developing diabetes mellitus. The findings in Belgian shepherds could be connected to a protective mechanism against the disease. Further insight into the regulation of glucose metabolism could improve diagnostic and therapeutic methods for diabetes mellitus.

Clinical usefulness of the measurement of serum fructosamine in childhood diabetes mellitus

PURPOSE

Glycosylated hemoglobin (HbA1c) is often used as an indicator of glucose control. It usually reflects the average glucose levels over two to three months, and is correlated with the development of long-term diabetic complications. However, it can vary in cases of hemoglobinopathy or an altered red blood cell lifespan. The serum fructosamine levels reflect the mean glucose levels over two to three weeks. This study was designed to determine the clinical usefulness of the combined measurement of serum fructosamine and HbA1c in the management of childhood diabetes mellitus and the correlation between them.

METHODS

Clinical data on 74 Korean children and adolescents with diabetes mellitus who were under management at the Department of Pediatrics of Dankook University Hospital were evaluated. Their fructosamine and HbA1c levels were reviewed based on clinical information, and analyzed using IBM SPSS Statistics ver. 21.

RESULTS

Their HbA1c levels showed a strong correlation with their fructosamine levels (r=0.868, P<0.001). The fructosamine level was useful for the prompt evaluation of the recent therapeutic efficacy after the change in therapeutic modality. It was also profitable in determining the initial therapeutics and for the estimation of the onset of the disease, such as fulminant diabetes.

CONCLUSION

The measurement of both fructosamine and HbA1c was useful in managing childhood diabetes mellitus, especially when there was discrepancy between the clinical information and the HbA1c level.

Amadori albumin in diabetic nephropathy

Nonenzymatic glycation of macromolecules in diabetes mellitus (DM) is accelerated due to persistent hyperglycemia. Reducing sugar such as glucose reacts non enzymatically with free €-amino groups of proteins through series of reactions forming Schiff bases. These bases are converted into Amadori product and further into AGEs. Non enzymatic glycation has the potential to alter the biological, structural and functional properties of macromolecules both in vitro and in vivo. Studies have suggested that amadori as well as AGEs are involved in the micro-macro vascular complications in DM, but most studies have focused on the role of AGEs in vascular complications of diabetes. Recently putative AGE-induced patho-physiology has shifted attention from the possible role of amadori-modified proteins, the predominant form of the glycated proteins in the development of the diabetic complications. Human serum albumin (HSA), the most abundant protein in circulation contains 59 lysine and 23 arginine residues that could, in theory be involved in glycation. Albumin has dual nature, first as a marker of intermediate glycation and second as a causative agent of the damage of tissues. Among the blood proteins, hemoglobin and albumin are the most common proteins that are glycated. HSA with a shorter half life than RBC, appears to be an alternative marker of glycemic control as it can indicate blood glucose status over a short period (2-3 weeks) and being unaffected by RBCs life span and variant haemoglobin, anemia etc which however, affect HbA1c. On the other hand, Amadori albumin may accumulate in the body tissues of the diabetic patients and participate in secondary complications. Amadori-albumin has potential role in diabetic glomerulosclerosis due to long term hyperglycaemia and plays an important role in the pathogenesis of diabetic nephropathy. This review is an approach to compile both the nature of glycated albumin as a damaging agent of tissues and as an intermediate diagnostic marker and its potential role in diabetic nephropathy.

Network-based approach for analyzing intra- and interfluid metabolite associations in human blood, urine, and saliva

Most studies investigating human metabolomics measurements are limited to a single biofluid, most often blood or urine. An organism's biochemical pool, however, comprises complex transboundary relationships, which can only be understood by investigating metabolic interactions and physiological processes spanning multiple parts of the human body. Therefore, we here propose a data-driven network-based approach to generate an integrated picture of metabolomics associations over multiple fluids. We performed an analysis of 2251 metabolites measured in plasma, urine, and saliva, from 374 participants of the Qatar Metabolomics Study on Diabetes (QMDiab). Gaussian graphical models (GGMs) were used to estimate metabolite-metabolite interactions on different subsets of the data set. First, we compared similarities and differences of the metabolome and the association networks between the three fluids. Second, we investigated the cross-talk between the fluids by analyzing correlations occurring between them. Third, we propose a framework for the analysis of medically relevant phenotypes by integrating type 2 diabetes, sex, age, and body mass index into our networks. In conclusion, we present a generic, data-driven network-based approach for structuring and visualizing metabolite correlations within and between multiple body fluids, enabling unbiased interpretation of metabolomics multifluid data.

Fructosamine is a useful indicator of hyperglycaemia and glucose control in clinical and epidemiological studies--cross-sectional and longitudinal experience from the AMORIS cohort

CONTEXT

Fructosamine is a glycemic biomarker which may be useful for indication and control of diabetes respectively.

OBJECTIVE

The objective of the study was to evaluate fructosamine as an indicator of hyperglycaemia and glucose control in subjects with diabetes.

DESIGN, SETTING & PATIENTS

From the AMORIS cohort, subjects with serum glucose, fructosamine and HbA1c from the same examination were studied cross-sectionally and longitudinally (n = 10,987; 5,590 overnight-fasting). The guidelines of the American Diabetes Association were followed for classification of prediabetes and diabetes. Separate analyses were performed in patients with a newly detected or a known diagnosis of type 1 or type 2 diabetes respectively.

RESULTS

All three biomarkers were strongly correlated. With regard to the association between fructosamine and HbA1c Pearson linear correlation coefficients in the range of 0.67-0.75 were observed in fasting and non-fasting subjects with type 1 or type 2 diabetes. Analyses of glucose control in fasting patients with type 2 diabetes having all three biomarkers measured at three separate occasions within on average 290 days of the index examination showed similar trends over time for glucose, fructosamine and HbA1c. Discrimination of subjects with and without diabetes across the range of fructosamine levels was good (area under curve (AUC) 0.91-0.95) and a fructosamine level of 2.5 mmol/L classified subjects to diabetes with a sensitivity of 61% and a specificity of 97%.

CONCLUSIONS

Fructosamine is closely associated with HbA1c and glucose respectively and may be a useful biomarker of hyperglycaemia and glucose control in clinical and epidemiological studies.

Beyond HbA1c and glucose: the role of nontraditional glycemic markers in diabetes diagnosis, prognosis, and management

Fasting glucose and hemoglobin A1c (HbA1c) are the standard measures for diagnosis and monitoring of diabetes. There has been recent interest in nontraditional markers of hyperglycemia, including fructosamine, glycated albumin, and 1,5-anhydroglucitol (1,5-AG), as alternatives or adjuncts to standard measures. There is a growing literature linking these nontraditional markers with microvascular and macrovascular complications. Fructosamine and glycated albumin have also been shown to improve identification of persons with diabetes. However, long-term prospective studies with clinical outcomes are lacking. Some modern laboratory assays for fructosamine, glycated albumin, and 1,5-AG have excellent performance. Expanded use of these tests has the potential to improve diabetes care as these measures may overcome limitations of HbA1c in certain patients, complement traditional measures by providing additional information on shorter-term glycemic control, and improve risk stratification for diabetes and its complications. Nonetheless, studies are needed to demonstrate if their routine use will benefit patients and improve outcomes.

Evaluation of glycemic variability in well-controlled type 2 diabetes mellitus

AIMS

It is necessary to evaluate glucose variability and postprandial hyperglycemia in patients with well-controlled type 2 diabetes mellitus because of the limitations associated with hemoglobin A1c (HbA1c) measurements. We evaluated parameters reflecting postprandial hyperglycemia and glycemic variability in patients with optimal HbA1c.

PATIENTS AND METHODS

Thirty-nine patients with HbA1c levels below 7% were recruited to the study. A continuous glucose monitoring system (CGMS) was applied for two 72-h periods. 1,5-Anhydroglucitol (1,5-AG) and fructosamine (FA) were measured as parameters for postprandial hyperglycemia and glucose variability. Using CGMS data, the following postprandial hyperglycemia parameters were calculated: mean postprandial maximum glucose (MPMG) and area under the curve for glucose above 180 mg/dL (AUC-180). To measure glycemic variability, we calculated mean amplitude of glucose excursion (MAGE) using a classical (MAGEc) and new method (MAGE group of sign [MAGEgos]).

RESULTS

The baseline HbA1c level was 6.3±0.3%. The mean MPMG was 10.34±1.84 mmol/L, and the mean AUC-180 was 0.17±0.23 mmol/L/day. The mean MAGEgos was 3.27±1.29 mmol/L, and MAGEc was 4.30±1.43 mmol/L, indicating glycemic variability in our patients. The mean levels of 1,5-AG and FA were 16.7±7.4 μg/mL and 273.0±22.5 μmol/L, respectively. In a correlation analysis, FA was significantly correlated with MPMG, AUC-180, MAGEgos, and MAGEc. In contrast, 1,5-AG was only correlated with AUC-180.

CONCLUSIONS

This study demonstrated postprandial hyperglycemia and glycemic variability in subjects with well-controlled diabetes. FA may reflect postprandial hyperglycemia and glycemic variability, but 1,5-AG may be of limited value for assessing glucose variability in patients with well-controlled type 2 diabetes mellitus.

Evaluation of biological variation of glycated albumin (GA) and fructosamine in healthy subjects

BACKGROUND

Glycated albumin (GA) and fructosamine are nonenzymatically glycated proteins still frequently utilized for monitoring glycemic control in diabetics. To investigate the analytical variation and the degree of individuality of these glycemic markers, we have performed an experimental study under a well designed and standardized protocol.

METHODS

We collected five specimens from each of 18 apparently healthy subjects (9 men and 9 women, ages 26-52 years), on the same day, every two weeks for two months. Samples were stored at -80°C until analysis and assayed in duplicate in a single analytical run. GA and fructosamine were measured using enzymatic (Lucica®GA-L, Asahi Kasei Pharma, AKP, Tokyo, Japan) and colorimetric assays, respectively, on a Modular P Roche system (Roche Diagnostics GmbH, Mannheim, Germany). Data were analyzed by ANOVA.

RESULTS

Analytical coefficient of variation (CVA) was 1.7%, 2.3% and 2.8% for GA, albumin and fructosamine, respectively. Within-subject (CVW) and between-subject (CVG) coefficients of variation were 2.1% and 10.6% for GA, 2.3% and 2.9% for albumin, and 2.3% and 6.3% for fructosamine. The estimated critical difference (CD) was 7.5% for GA, 9% for albumin and 10% for fructosamine.

CONCLUSIONS

The good quality achieved by the analytical method for GA assessment and the reduced within-subject biological variation would allow to recommend this test in clinical practice for evaluation of glycemic control along with measurement of glycated hemoglobin.

Proteome-base biomarkers in diabetes mellitus: progress on biofluids' protein profiling using mass spectrometry

The worldwide number of individuals suffering from diabetes mellitus (DM) has been projected to rise from 171 million in 2000 to 366 million in 2030. Identification of specific biomarkers for prediction and monitoring of DM is needed not only for the adequate screening diagnosis but also to assist the design of interventions to prevent or delay progression of this pathology and its attendant complications. Proteomic methods based on MS hold special promise for the identification of novel biomarkers that might form the foundation for new clinical tests, but to date, their contribution has been somehow unfruitful. Indeed, from more than 300 proteins found differently modulated in body fluids from diabetic patients, approximately 50 were validated with other approaches like ELISA or Western blotting and the clinical trials are being initiated to employ biofluids' proteomics (specifically urinary proteomics) in clinical decision. This review provides an overview of MS-based applications in the identification of potential biomarkers for DM, emphasizing the methodological challenges involved.

Sitagliptin as add-on therapy in insulin deficiency: biomarkers of therapeutic efficacy respond differently in type 1 and type 2 diabetes

Background

Sitagliptin has been proven to be effective and safe as add-on to insulin in adult patients with type 2 diabetes and absolute insulin deficiency. Recently, it has been suggested to extend the use of dipeptidyl-peptidase-4 inhibitors to type 1 diabetes. The aim of this study was to evaluate and compare the effects of a long-term, fixed-dose combination of sitagliptin and metformin as add-on to insulin on body mass index, fasting plasma glucose, fructosamine, HbA_1c, lipids, and daily dose of insulin in both type 1 diabetes and insulin-treated type 2 diabetes.

Methods

We recruited 25 patients with type 1 diabetes (mean age 51 ± 10 years, mean disease duration 26 ± 13 years) and 31 insulin-treated type 2 diabetic patients (mean age 66 ± 8 years, mean disease duration 19 ± 9 years), who received sitagliptin with metformin as a fixed-dose combination (50/1000 mg once or twice daily) or sitagliptin (100 mg once daily, if intolerant to metformin) in addition to ongoing insulin therapy for 46 ± 19 weeks and 56 ± 14 weeks, respectively.

Results

After 21 ± 9 weeks, patients with type 1 diabetes had a significantly lower body mass index, fasting plasma glucose, fructosamine, HbA_1c, and daily insulin requirement. After 49 ± 17 weeks, they maintained their weight loss and total daily insulin dose and showed a significant reduction in low-density lipoprotein cholesterol levels, whereas their HbA_1c had returned to baseline values. In patients with type 2 diabetes, long-term treatment remained weight-neutral but had persistent beneficial effects on short-term, intermediate-term, and long-term biomarkers of metabolic control, as well as on low-density lipoprotein cholesterol levels and insulin requirement.

Conclusion

Clinical outcomes differed according to type of diabetes in terms of quality and over time. In type 2 diabetes, the combination therapy significantly improved metabolic control and the lipid profile, and decreased insulin requirements, even in the absence of clinically significant weight loss. In type 1 diabetes, the combined therapy only temporarily improved metabolic control, but significantly decreased body weight, low-density lipoprotein cholesterol levels, and insulin requirements.

Serum glucose and fructosamine in relation to risk of cancer

BACKGROUND

Impaired glucose metabolism has been linked with increased cancer risk, but the association between serum glucose and cancer risk remains unclear. We used repeated measurements of glucose and fructosamine to get more insight into the association between the glucose metabolism and risk of cancer.

METHODS

We selected 11,998 persons (>20 years old) with four prospectively collected serum glucose and fructosamine measurements from the Apolipoprotein Mortality Risk (AMORIS) study. Multivariate Cox proportional hazards regression was used to assess standardized log of overall mean glucose and fructosamine in relation to cancer risk. Similar analyses were performed for tertiles of glucose and fructosamine and for different types of cancer.

RESULTS

A positive trend was observed between standardized log overall mean glucose and overall cancer risk (HR= 1.08; 95% CI: 1.02-1.14). Including standardized log fructosamine in the model resulted in a stronger association between glucose and cancer risk and aninverse association between fructosamine and cancer risk (HR = 1.17; 95% CI: 1.08-1.26 and HR: 0.89; 95% CI: 0.82-0.96, respectively). Cancer risks were highest among those in the highest tertile of glucose and lowest tertile of fructosamine. Similar findings were observed for prostate, lung, and colorectal cancer while none observed for breast cancer.

CONCLUSION

The contrasting effect between glucose, fructosamine, and cancer risk suggests the existence of distinct groups among those with impaired glucose metabolism, resulting in different cancer risks based on individual metabolic profiles. Further studies are needed to clarify whether glucose is a proxy of other lifestyle-related or metabolic factors.

The roles of glycated albumin as intermediate glycation index and pathogenic protein

The conventional glycemic indices used in management of diabetic patients includes A1c, fructosamine, 1,5-anhydroglucitol, and glycated albumin (GA). Among these indices, A1c is currently used as the gold standard. However, A1c cannot reflect the glycemic change over a relatively short period of time, and its accuracy is known to decrease when abnormalities in hemoglobin metabolism, such as anemia, coexist. When considering these weaknesses, there have been needs for finding a novel glycemic index for diagnosing and managing diabetes, as well as for predicting diabetic complications properly. Recently, several studies have suggested the potential of GA as an intermediate-term glycation index in covering the short-term effect of treatment. Furthermore, its role as a pathogenic protein affecting the worsening of diabetes and occurrence of diabetic complications is receiving attention as well. Therefore, in this article, we wanted to review the recent status of GA as a glycemic index and as a pathogenic protein.

Biomarkers for Diabetes Complications: The Results of Several Clinical Studies

Diabetes is a common metabolic disorder. Its microvascular and macrovascular complications contribute to death, disabilities, and reduction in life expectancy in diabetes. It is a costly disease, and affects not only the patient and family, but also the public health, communities and society. It takes an increasing proportion of the national health care expenditure. The prevention of the development of diabetes and its complications is a major concern. Biomarkers have been investigated for understanding the mechanisms of the development and progression of diabetic complications. In this paper, the biomarkers which are recommended in the clinical practice and laboratory medicine guidelines, and which have been investigated for prediction or diagnosis of diabetes complications, have been reviewed. The results of several clinical studies will be summarized.

Racial differences in glycemic markers: a cross-sectional analysis of community-based data

BACKGROUND

Although differences between black and white persons in hemoglobin A(1c) (HbA(1c)) values are well established, recent studies suggest that this might not reflect differences in glycemia.

OBJECTIVE

To investigate racial disparities in glycemic markers, including those that reflect biological processes independent of hemoglobin glycation and erythrocyte turnover.

DESIGN

Cross-sectional.

SETTING

Community-based.

PARTICIPANTS

1376 nondiabetic and 343 diabetic adults in a substudy of the Atherosclerosis Risk in Communities Study.

MEASUREMENTS

Hemoglobin A(1c), fasting glucose, glycated albumin, fructosamine, and 1,5-anhydroglucitol levels.

RESULTS

Among persons with and without diabetes, black persons had significantly higher HbA(1c), glycated albumin, and fructosamine levels than white persons before and after adjustment for covariates and fasting glucose concentration. Serum 1,5-anhydroglucitol levels, which are reduced in the setting of hyperglycemia-induced glycosuria, were lower in black persons than in white persons, although this difference was statistically significant only in nondiabetic adults.

LIMITATION

The design was cross-sectional, a limited number of participants with a history of diabetes was included, and the study did not include integrated measures of circulating nonfasting glycemia.

CONCLUSION

Differences between black and white persons in glycated albumin, fructosamine, and 1,5-anhydroglucitol levels parallel differences between these groups in HbA(1c) values. Racial differences in hemoglobin glycation and erythrocyte turnover cannot explain racial disparities in these serum markers. The possibility that black persons have systematically higher levels of nonfasting glycemia warrants further study.

PRIMARY FUNDING SOURCE

National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.

The personalized medicine for diabetes meeting summary report

Personalized medicine for diabetes is a potential method to specifically identify people who are at high risk of developing type 2 diabetes based on a combination of personal history, family history, physical examination, circulating biomarkers, and genome. High-risk individuals can then be referred to lifestyle programs for risk reduction and disease prevention. Using a personalized medicine approach, a patient with already-diagnosed type 2 diabetes can be treated individually based on information specific to that individual. The field of personalized medicine for diabetes is rapidly exploding. Diabetes Technology Society convened the Personalized Medicine for Diabetes (PMFD) Meeting March 19-20, 2009 in San Francisco. The meeting was funded through a contract from the US Air Force. Diabetes experts from the military, government, academic, and industry communities participated. The purpose was to reach a consensus about PMFD in type 2 diabetes to (a) establish screening programs, (b) diagnose cases at an early stage, and (c) monitor and treat the disease with specific measures. The group defined what a PMFD program should encompass, what the benefits and drawbacks of such a PMFD program would be, and how to overcome barriers. The group reached six conclusions related to the power of PMFD to improve care of type 2 diabetes by resulting in (1) better prediction, (2) better prophylactic interventions, (3) better treatments, and (4) decreased cardiovascular disease burden. Additional research is needed to demonstrate the benefits of this approach. The US Air Force is well positioned to conduct research and develop clinical programs in PMFD.