Diagnosis and Classification of Diabetes Mellitus

The metabolic syndrome has received increased attention in the past few years. This statement from the American Heart Association (AHA) and the National Heart, Lung, and Blood Institute (NHLBI) is intended to provide up-to-date guidance for professionals on the diagnosis and management of the metabolic syndrome in adults.

The metabolic syndrome is a constellation of interrelated risk factors of metabolic origin— metabolic risk factors —that appear to directly promote the development of atherosclerotic cardiovascular disease (ASCVD).1 Patients with the metabolic syndrome also are at increased risk for developing type 2 diabetes mellitus. Another set of conditions, the underlying risk factors , give rise to the metabolic risk factors. In the past few years, several expert groups have attempted to set forth simple diagnostic criteria to be used in clinical practice to identify patients who manifest the multiple components of the metabolic syndrome. These criteria have varied somewhat in specific elements, but in general they include a combination of both underlying and metabolic risk factors.

The most widely recognized of the metabolic risk factors are atherogenic dyslipidemia, elevated blood pressure, and elevated plasma glucose. Individuals with these characteristics commonly manifest a prothrombotic state and a pro-inflammatory state as well. Atherogenic dyslipidemia consists of an aggregation of lipoprotein abnormalities including elevated serum triglyceride and apolipoprotein B (apoB), increased small LDL particles, and a reduced level of HDL cholesterol (HDL-C). The metabolic syndrome is often referred to as if it were a discrete entity with a single cause. Available data suggest that it truly is a syndrome, ie, a grouping of ASCVD risk factors, but one that probably has more than one cause. Regardless of cause, the syndrome identifies individuals at an elevated risk for ASCVD. The magnitude of the increased risk can vary according to which components of the syndrome are …

https://www.lipidcenter.com/pdf/metabolic.pdf

Diagnosis and Management of the Metabolic Syndrome An American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement

The metabolic syndrome—a new worldwide definition

The National Cholesterol Education Program’s Adult Treatment Panel III report (ATP III)1 identified the metabolic syndrome as a multiplex risk factor for cardiovascular disease (CVD) that is deserving of more clinical attention. The cardiovascular community has responded with heightened awareness and interest. ATP III criteria for metabolic syndrome differ somewhat from those of other organizations. Consequently, the National Heart, Lung, and Blood Institute, in collaboration with the American Heart Association, convened a conference to examine scientific issues related to definition of the metabolic syndrome. The scientific evidence related to definition was reviewed and considered from several perspectives: (1) major clinical outcomes, (2) metabolic components, (3) pathogenesis, (4) clinical criteria for diagnosis, (5) risk for clinical outcomes, and (6) therapeutic interventions.

ATP III viewed CVD as the primary clinical outcome of metabolic syndrome. Most individuals who develop CVD have multiple risk factors. In 1988, Reaven2 noted that several risk factors (eg, dyslipidemia, hypertension, hyperglycemia) commonly cluster together. This clustering he called Syndrome X , and he recognized it as a multiplex risk factor for CVD. Reaven and subsequently others postulated that insulin resistance underlies Syndrome X (hence the commonly used term insulin resistance syndrome ). Other researchers use the term metabolic syndrome for this clustering of metabolic risk factors. ATP III used this alternative term. It avoids the implication that insulin resistance is the primary or only cause of associated risk factors. Although ATP III identified CVD as the primary clinical outcome of the metabolic syndrome, most people with this syndrome have insulin resistance, which confers increased risk for type 2 diabetes. When diabetes becomes clinically apparent, CVD risk rises sharply. Beyond CVD and type 2 diabetes, individuals with metabolic syndrome seemingly are susceptible to other conditions, notably polycystic ovary syndrome, fatty liver, cholesterol gallstones, asthma, sleep disturbances, and some …

https://cdr.lib.unc.edu/downloads/2801pj553

Definition of Metabolic Syndrome Report of the National Heart, Lung, and Blood Institute/American Heart Association Conference on Scientific Issues Related to Definition

Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute scientific statement.

In 1997, an International Expert Committee was convened to reexamine the classification and diagnostic criteria of diabetes, which were based on the 1979 publication of the National Diabetes Data Group (1) and subsequent WHO study group (2). As a result of its deliberations, the Committee recommended several changes to the diagnostic criteria for diabetes and for lesser degrees of impaired glucose regulation (IFG/IGT) (3). The following were the major changes or issues addressed. 1) The use of a fasting plasma glucose (FPG) test for the diagnosis of diabetes was recommended, and the cut point separating diabetes from nondiabetes was lowered from FPG 140 mg/dl (7.8 mmol/l) to 126 mg/dl (7.0 mmol/l). (All glycemic values represent venous plasma.) This change was based on data that showed an increase in prevalence and incidence of diabetic retinopathy beginning at approximately a FPG of 126 mg/dl, as well as on the desire to reduce the discrepancy that existed in the number of cases detected by the FPG cut point of 140 mg/dl and the 2-h value in the OGTT (2-h plasma glucose [2-h PG]) of 200 mg/dl (11.1 mmol/l). 2) Normal FPG was defined as 110 mg/dl (6.1 mmol/l). 3) The use of HbA1c (A1C) as a diagnostic test for diabetes was not recommended. The primary reason for this decision was a lack of standardized methodology resulting in varying nondiabetic reference ranges among laboratories. 4) Although the OGTT (which consists of an FPG and 2-h PG value) was recognized as a valid way to diagnose diabetes, the use of the test for diagnostic purposes in clinical practice was discouraged for several reasons (e.g., inconvenience, less reproducibility, greater cost). The diagnostic category of impaired glucose tolerance (IGT) was retained to describe people whose FPG was 126 mg/dl but whose 2-h PG after a 75-g oral glucose challenge was 140–199 mg/dl. 5) The range of FPG levels between “normal” and that diagnostic for diabetes was named “impaired fasting glucose” (IFG). IFG identified people whose FPG ranged from 110 mg/dl (6.1 mmol/l) to 125 mg/dl (6.9 mmol/l). This construct was established so that there would be a fasting category analogous to IGT. The WHO consultation (4) also adopted most of the above conclusions. The two significant differences were that, whenever feasible, individuals with IFG should receive an OGTT to exclude the presence of diabetes, and the adoption of different criteria for the diagnosis of gestational diabetes. Since the 1997 Expert Committee report, many new data related to the diagnosis of diabetes have been published. First, many analyses of both old and new epidemiological data have examined the equivalence of the FPG and the 2-h PG to predict diabetes, and questions have been raised about the preference of the FPG test over the 2-h PG to diagnose diabetes (5– 7). Second, the IGT category has now been associated with cardiovascular disease (CVD) risk factors (8–10) and CVD events (10,11), whereas IFG is much less strongly associated with CVD events and CVD mortality (10,11). Third, the National Glycosylated Hemoglobin Standardization Program (NGSP) has now ensured that most laboratories in the U.S. perform the assays using standardized controls and report glycated hemoglobin results in a manner traceable to the assay used in the Diabetes Control and Complications Trial (DCCT) (12). These development s have improved as say performance and now allow caregivers and patients to compare reported results obtained among laboratories. Additional studies have suggested that the A1C may assist in diagnosing diabetes (13–17). Finally, data from major clinical trials that tested whether the progression from IGT to diabetes could be delayed or prevented by a treatment intervention have produced concordant results: intensive lifestyle modification (nutritional and exercise interventions) (18,19), metformin (19,20), and acarbose (20,21) were effective to variable degrees. In addition, a thiazolidinedione drug (troglitazone) reduced the incidence of diabetes in high-risk women with prior gestational diabetes (22). An inherent difficulty in the diagnosis of diabetes is the present lack of an identified unique qualitative biological marker that separates all people with diabetes from all nondiabetic individuals. The closest such characteristic for practical purposes is diabetic retinopathy, but this suffers from the obvious defect that in most diabetic patients, retinopathy usually becomes evident years after the recognized onset of diabetes. The lack of a suitable, unique marker of diabetes has led to reliance on the metabolic abnormality historically associated with the disease, i.e., hyperglycemia (as measured by the FPG or 2-h PG) as the most useful diagnostic test. The selection of diagnostic cut points for these tests rests on two ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●

/pdf/follow-up-report-on-the-diagnosis-of-diabetes-mellitus-3gkidygqi2.pdf

Follow-up report on the diagnosis of diabetes mellitus.

OBJECTIVE —HbA 1c is a standard clinical assessment of glycemia and the basis of most data relating glycemic control to complications. It remains unclear, however, whether HbA 1c is affected by glycemic variation and mean glycemia. RESEARCH DESIGN AND METHODS —To test this question, we analyzed the statistical relationship between HbA 1c levels and glycemic variability as measured by self-monitoring of blood glucose (SMBG). The records of 256 subjects were studied. SMBG data for the preceding 3 months were downloaded, and HbA 1c was measured by ion-exchange high-performance liquid chromatography. Simple- and random-effects linear regression models were used to assess the independent contributions of mean blood glucose (BG) and SD of BG to HbA 1c , after adjusting for the mean BG. RESULTS —Mean ± SD for HbA 1c was 7.66 ± 1.11% and for BG was 8.5 ± 1.9 mmol/l (153.3 ± 34.9 mg/dl); SD of BG for individual subjects was 3.5 mmol/l (63.3 mg/dl), varying from 0.4 mmol/l (8.1 mg/dl; very stable glycemia) to 8.4 mmol/l (152.5 mg/dl; very unstable glycemia). A close correlation between mean BG and HbA 1c was demonstrated ( r = 0.62). Also, within-subject SD of BG correlated with HbA 1c ( r = 0.375), indicating that people with poorer glycemic control had higher BG variance. After adjusting for mean BG in a linear regression model, however, the effect of the within-subject SD of BG on the HbA 1c was insignificant. Several further analyses confirmed the strength of the observation. CONCLUSIONS —HbA 1c reflects mean glycemia and is not meaningfully affected by glycemic instability after adjusting for mean BG.

https://care.diabetesjournals.org/content/diacare/26/10/2728.full.pdf

Is HbA1c Affected by Glycemic Instability

Objective To examine the effect of diabetes education on self-regulation and life-style behaviors. Research Design and Methods Participants in an outpatient diabetes education program completed a protocol measuring several self-care behaviors and glycemic control at entry ( n = 165) and 6 ( n = 124) and 12 ( n = 89) mo after the program. Results Improvement was noted at 6 mo for most self-care behaviors and glycemic control. At 12 mo, lower glycosylated hemoglobin levels were maintained ( P P Conclusions The findings suggest that diabetes education is effective in promoting self-regulation behaviors, although it has less effect on traditional regimen behaviors such as diet and exercise.

Differential Effect of Diabetes Education on Self-Regulation and Life-Style Behaviors

OBJECTIVE—To use bone marrow transplantation (BMT) as a model for testing the association between hyperglycemia and infection. RESEARCH DESIGN AND METHODS—This cohort study included 382 adults (6.5% with diabetes) who had no evidence of infection before neutropenia during BMT. Mean glucose was calculated from central laboratory and bedside measurements taken before neutropenia; the primary outcome was neutropenic infections. RESULTS—Eighty-four patients (22%) developed at least one neutropenic infection, including 51 patients (13%) with bloodstream infections. In patients who did not receive glucocorticoids during neutropenia, each 10 mg/dl increase in mean preneutropenia glucose was associated with an odds ratio of 1.08 (95% CI 0.98–1.19) (P = 0.14) for any infection and 1.15 (1.03–1.28) (P = 0.01) for bloodstream infections, after adjusting for age, sex, race, year, cancer diagnosis, transplant type, and total glucocorticoid dose before neutropenia. In those who received glucocorticoids during neutropenia (n = 71), the adjusted odds ratio associated with a 10 mg/dl increase in mean glucose was 1.21 (1.09–1.34) (P CONCLUSIONS—In a BMT population highly susceptible to infection, there was a continuous positive association between mean antecedent glycemia and later infection risk, particularly in patients who received glucocorticoids while neutropenic. Tight glycemic control during BMT and glucocorticoid treatment may reduce infections.

https://care.diabetesjournals.org/content/diacare/31/10/1972.full.pdf

Antecedent hyperglycemia is associated with an increased risk of neutropenic infections during bone marrow transplantation.

Questions are sometimes raised by employers about the safety and effectiveness of individuals with diabetes in a given job. When such questions are legitimately raised, a person with diabetes should be individually assessed to determine whether or not that person can safely and effectively perform the particular duties of the job in question. This document provides a general set of guidelines for evaluating individuals with diabetes for employment, including how an assessment should be performed and what changes (accommodations) in the workplace may be needed for an individual with diabetes.

Christopher D Saudek

Papers

Follow-up report on the diagnosis of diabetes mellitus.

Is HbA1c Affected by Glycemic Instability

Differential Effect of Diabetes Education on Self-Regulation and Life-Style Behaviors

Antecedent hyperglycemia is associated with an increased risk of neutropenic infections during bone marrow transplantation.

Diabetes and employment.