Usefulness of Fructosamine for Monitoring Outpatients with Diabetes

Recent Developments in Biomarkers for Diagnosis and Screening of Type 2 Diabetes Mellitus

PURPOSE OF REVIEW

Diabetes mellitus is a complex, chronic illness characterized by elevated blood glucose levels that occurs when there is cellular resistance to insulin action, pancreatic β-cells do not produce sufficient insulin, or both. Diabetes prevalence has greatly increased in recent decades; consequently, it is considered one of the fastest-growing public health emergencies globally. Poor blood glucose control can result in long-term micro- and macrovascular complications such as nephropathy, retinopathy, neuropathy, and cardiovascular disease. Individuals with diabetes require continuous medical care, including pharmacological intervention as well as lifestyle and dietary changes.

RECENT FINDINGS

The most common form of diabetes mellitus, type 2 diabetes (T2DM), represents approximately 90% of all cases worldwide. T2DM occurs more often in middle-aged and elderly adults, and its cause is multifactorial. However, its incidence has increased in children and young adults due to obesity, sedentary lifestyle, and inadequate nutrition. This high incidence is also accompanied by an estimated underdiagnosis prevalence of more than 50% worldwide. Implementing successful and cost-effective strategies for systematic screening of diabetes mellitus is imperative to ensure early detection, lowering patients' risk of developing life-threatening disease complications. Therefore, identifying new biomarkers and assay methods for diabetes mellitus to develop robust, non-invasive, painless, highly-sensitive, and precise screening techniques is essential. This review focuses on the recent development of new clinically validated and novel biomarkers as well as the methods for their determination that represent cost-effective alternatives for screening and early diagnosis of T2DM.

Emerging Diabetic Novel Biomarkers of the 21st Century

Diabetes is a growing epidemic with estimated prevalence of infected to reach ~592 million by the year 2035. An effective way to approach is to detect the disease at a very early stage to reduce the complications and improve lifestyle management. Although several traditional biomarkers including glucated hemoglobin, glucated albumin, fructosamine, and 1,5-anhydroglucitol have helped in ease of diagnosis, there is lack of sensitivity and specificity and are inaccurate in certain clinical settings. Thus, search for new and effective biomarkers is a continuous process with an aim of accurate and timely diagnosis. Several novel biomarkers have surged in the present century that are helpful in timely detection of the disease condition. Although it is accepted that a single biomarker will have its inherent limitations, combining several markers will help to identify individuals at high risk of developing prediabetes and eventually its progression to frank diabetes. This review describes the novel biomarkers of the 21st century, both in type 1 and type 2 diabetes mellitus, and their present potential for assessing risk stratification due to insulin resistance that will pave the way for improved clinical outcome.

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

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.

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.

Interinstitutional variation in glycohemoglobin monitoring and glycemic control of diabetic patients

OBJECTIVES

To compare how frequently institutions monitor glycohemoglobin in diabetic patients, the level of glycemic control achieved and to identify institutional factors associated with higher rates of monitoring and lower glycohemoglobin levels.

METHODS

A total of 212 institutions retrospectively abstracted laboratory and outpatient records of up to 30 diabetic patients who had initial glycohemoglobin monitoring performed in their laboratories. Data from a cohort of 5586 diabetic patients and 17 365 assays were analyzed.

RESULTS

Overall, 31.3% of patients underwent glycohemoglobin monitoring at least quarterly, the frequency recommended by the American Diabetes Association (ADA) to stabilize patients at target hemoglobin A(1c) (HbA(1c)) levels. A total of 64.9% of patients were monitored at least semiannually, the ADA recommendation for patients with stable diabetes in glycemic control (final HbA(1c) level <7%). When we compared the top and bottom deciles of the 212 institutions, there was more than an eightfold difference in the proportion of patients monitored at least quarterly and more than a twofold difference in the proportion of patients monitored at least semiannually. Glycemic control was assessed by examining the value of the last glycohemoglobin determination on record after at least 8 months of management. For all 5586 diabetic patients, the median value of the last HbA(1c) assay was 7.4%. Comparing the top and bottom deciles, there was almost a fourfold difference among institutions in the proportion of diabetic patients in glycemic control. The use of reminders to order glycohemoglobin monitoring was associated with higher rates of semiannual monitoring (P <.05) and tighter glycemic control (P <.05). In addition, patients who were monitored more frequently experienced glycohemoglobin reductions of greater magnitude (P <.001). The presence of diabetes clinics and the use of rapid methods for testing glycohemoglobin were not associated with monitoring frequency or glycohemoglobin levels.

CONCLUSIONS

There is wide interinstitutional variation in the frequency with which diabetic patients are monitored and the level of glycemic control achieved. The use of prompting systems to remind providers to order glycohemoglobin monitoring was associated with more frequent monitoring and superior glycemic control.