Elsevier

Burns

Volume 39, Issue 5, August 2013, Pages 881-884
Burns

Utility of screening for diabetes in a burn center: Hemoglobin A1c, Diabetes Risk Test, or simple history?

https://doi.org/10.1016/j.burns.2012.10.009Get rights and content

Abstract

Objective

Rates of diabetes mellitus (DM) are increasing. Early identification and treatment of hyperglycemia in the critical care setting can decrease morbidity and mortality. Many burn centers measure hemoglobin A1c (A1c). This study evaluates the prevalence of pre-existing DM and the utility of using A1c for identifying DM compared with a non-invasive risk assessment.

Methods

Adult patients admitted to our regional ABA-verified burn center from July 2008 to July 2009 had A1c levels evaluated and were asked to complete the American Diabetes Association Diabetes Risk Test (DRT).

Results

Forty-one patients consented to participate: 24 patients with burn (19 male) and 17 patients with non-burns (10 male). Non-burn patients had greater BMIs (BMI 32 vs. 28, p = 0.093) and had a higher rate of DM prior to admission (35% vs. 17%, p = 0.159) than the burn patients. These differences were not statistically significant. Most patients (23/41) were at high risk for developing DM based on the DRT. Patients with pre-existing DM were significantly more likely to have elevated A1c levels (>6.5%) compared with those without pre-existing DM (60% vs. 0%, p < 0.001). Compared with history of DM, DRT had a poor positive predictive value of 36% and 50% (burn and non-burn respectively) but a 100% negative predictive value for DM for both groups.

Conclusion

DM and obesity were more common in non-burn patients than in burn patients. A history of DM provides a simple, accurate method for identifying patients with DM. Use of A1c in the ICU provides little additional data for diagnosis of DM and does not impact patient management.

Introduction

The documented prevalence of diabetes mellitus (DM) is greater than 8% in the United States and is expected to rise as the American population ages and becomes more obese [1], [2]. Using National Health and Nutrition Examination Survey data, Cowie reported a rise of over 2% over a 15-year period. Hyperglycemia, whether stress-induced or pre-existing, is a risk factor for mortality in intensive care units [2], [3], [4], [5]. Recent studies in ICU and burn populations have demonstrated that strict glucose control via intensive insulin therapy may improve patient outcomes although recommendations vary on target glucose range [5], [6], [7], [8]. Many studies over the past decade have led to widespread implementation of insulin protocols and more aggressive glucose control [6]. Improved outcomes have been documented with lower glucose levels in patients with and without pre-existing DM [6], [9], [10], [11].

Many patients admitted to intensive care units utilise insulin therapy and, while metabolic stress affects glucose levels, these patients may also have undiagnosed DM or insulin resistance related to metabolic syndrome. Unfortunately, the incidence of these disorders and their impact on the care of acutely hospitalized patients is unknown. Prior to 2010 the ADA recommended using a fasting glucose threshold (FG  7.0 mmol/l) or an impaired oral glucose tolerance test (OGTT) [2]. Neither of these methods is accurate during an acute hospitalization as the stress response can affect glucose levels. An alternate test, hemoglobin A1c (A1c), estimates glucose levels over the 120 days prior to testing. The ADA recently endorsed A1c as diagnostic test for DM [12]. There have been several studies suggesting that elevated A1c may predict DM [13], [14]. Unlike the OGTT, A1c is relatively easy to obtain in an ICU setting.

In 2008, due to concerns about the challenges of glucose control in burn patients and the increased societal prevalence of DM we initiated a practice of routinely obtaining A1c levels in patients over age 25 admitted to our regional burn center. This study was designed as a preliminary evaluation of the utility of A1c compared to medical history or simple evalutation of diabetic risk factors to identify patients with DM. We chose the validated ADA Diagnostic Risk Test (DRT) to identify patients at high risk for developing DM. This test was developed to identify people in the general population with a high risk for developing DM. The self-administered, seven-item, weighted response test includes questions about weight, age, activity, family and medical history (Fig. 1). While many burn centers report routine screening using A1c we hypothesized that A1c is no more useful than non-invasive methods for identifying patients with DM in the burn ICU setting.

Section snippets

Methods

This study was a prospective, descriptive evaluation of three methods of screening for diabetes risk in patients admitted to an ABA verified burn center: A1c, American Diabetes Association Diabetes Risk Test (DRT), and patient history.

Each question of the DRT (Fig. 1) is individually scored. Weight risk is not based on Body Mass Index (BMI) but by the chart shown in Fig. 2. DRT scores greater or equal to 10 were defined (per American Diabetes Association standards) as high risk for developing

Results

During the one-year time period of this study, 183 patients >25 years old were admitted to our burn center. Forty-two patients were discharged before they could be approached for participation. Of the remaining 141 patients, 96 (52%) had an A1c level obtained (Table 1); there were four deaths and eight patients were unable to give consent due to a language or other communication barrier. Of the 84 patients remaining, 41 (49%) consented to participate.

There were 24 patients admitted for acute

Discussion

Rates of DM in hospitalized patients range from <5% to near 30% [10], [11], [15], [16]. Our incidence of DM was higher than nationally reported rates of DM for the general population (25% vs. <10%) but was consistent with those reported in studies in hospitalized and ICU patients [9], [10]. This may reflect the average age of the patients and that most of our non-burn patients had soft tissue infections, a disease process commonly associated with DM.

Hyperglycemia in acutely ill patients is

Conclusions

The DRT is fast, simple and easily obtained. There was no advantage in using A1c to identify patients with DM and, though A1c is a relatively inexpensive laboratory test, it is more expensive and invasive than a questionnaire. In this study we did not identify any patients with DM who were not identified with a careful, complete medical history. While an elevated A1c can assist in identifying and referring those in need and who might benefit from further diabetes management, it may not provide

Conflict of interest

Authors have no financial interests to disclose.

References (19)

There are more references available in the full text version of this article.

Cited by (5)

  • Clinical outcomes following burn injury across the continuum of chronic glycemic control

    2021, Burns
    Citation Excerpt :

    Diabetes is known to complicate care in burn patients and increase length of stay [7,11]. As the diabetic population is expected to continue to increase, efforts have been made to better delineate various hyperglycemic states such as stress induced hyperglycemia (SIH), prediabetes, and uncontrolled diabetes in relation to clinical outcomes and care [8,12,19]. Although there have been many studies comparing diabetic and non-diabetic burn patients, we are unaware of any studies that compare the clinical significance of diabetic, prediabetic, and non-diabetic groups across the continuum of pre-injury chronic glucose control [5,10,20].

  • The year in burns 2013

    2014, Burns
    Citation Excerpt :

    A history of DM provides a simple, accurate method for identifying patients with DM. Use of A1c in the ICU provides little additional data for diagnosis of DM and does not impact patient management [47]. The next 4 papers involve investigation of metabolic parameters after burn.

View full text