Although there are no statistically significant differences between the two study groups, clinical trends were identified. These trends suggest a longer time to clinical stability and higher mortality in patients having long term abnormal glucose control. This trend and possible relationship correlate with the findings of Kornum, et al 7 as their cohort study found that diabetics with poor long term glycemic control had a significant increase in the risk of hospitalization from CAP. In contrast, Chen et al 8 found no association between tight glucose control in diabetics and the incidence of LTCF (long term care facility) pneumonia.

Patients with diabetes mellitus have abnormalities in the immune system that predisposes them to infections. In vitro studies have associated hyperglycemia with abnormal neutrophil function such as impaired chemotaxis, phagocytosis and bacteria killing.9 Thus diabetics, especially if uncontrolled, are at increased risk for morbidity and mortality associated with community-acquired pneumonia (CAP). It is unclear if the immune abnormalities are due to the diagnosis of DM by itself or due to the poor glycemic control associated with DM.  Further research may help differentiate if it is the diagnosis of diabetes itself, or control of diabetes, that leads to worse outcomes compared to non-diabetics.

 

Impact of Glycemic Control on the Outcomes of Hospitalized Patients with CAP: Results from the CAPO International Cohort Study

Jaimini Jodhani, Rehab Abdelfattah, Fabiola Gianella, Amy Holloway, Robert Kelley, Paula PeyraniDepartment of Infectious Diseases

University of Louisville School of Medicine

ABSTRACT

INTRODUCTION:Patients with diabetes mellitus (DM) have abnormalities in the immune system that predisposes them to infections. The literature indicates that patients with DM are at increased risk for morbidity and mortality associated with community-acquired pneumonia (CAP). It is unclear if the immune abnormalities are due to DM by itself or due to the abnormal glycemic control. The objective of this study was to compare the severity and clinical outcomes of CAP in patients with DM with and without glycemic control.

MATERIALS AND METHODS:This was a secondary data analysis of the Community Acquired Pneumonia Organization (CAPO) international cohort study database. Based on normal or abnormal HgA1c, patients with a clinical history of DM were classified as having normal or abnormal glucose control. Severity of disease was defined according to the pneumonia severity index (PSI). Clinical outcomes studied included: time to clinical stability and in-hospital mortality.

RESULTS:A total of 70 patients were included in the study. Normal glucose control was defined in 33 patients, and abnormal was defined in 37 patients. Both groups of patients showed no statistically significant differences in severity of clinical outcomes. Results can be found in Table 1

 

Table 1

CONCLUSIONS:Although there are no statistically significant differences between study groups, clinical trends were identified. These trends suggest a longer time to clinical stability and higher mortality in patients having abnormal glucose control. The immune suppression associated with DM may correlate with the glucose level, indicating that optimal glucose control may alter the outcome of these patients.

INTRODUCTION (cont) CONCLUSIONS

REFERENCES

MATERIALS AND METHODS

Study design: secondary data analysis of the Community Acquired Pneumonia Organization (CAPO) international cohort study database.

Study population: patients who were hospitalized at the Robley Rex VA Medical Center from Sept. 2001 to November 2005 and had a HbA1c documented in the chart from 3 months prior to admission to 1 week from date of admission.

Study definitions: CAP was defined as

Abnormal HbA1c: >7

Severity of CAP: according to the pneumonia severity index (PSI) – classes IV/V

Clinical outcomes studied: time to clinical stability and in-hospital mortality. 2001 ATS criteria for clinical stability:1. Cough or shortness of breath (improving or at baseline)2. Afebrile for > 8 hrs (>38°C or >100°F)3. Improvement in leukocyte count by >10%4. Oral intake and absorption adequate Statistical analysis: For dichotomous variables, chi-square and fisher’s exact test were used when appropriate

1. Centers for Disease Control and Prevention Web site. Pneumonia. Available at: http://www.cdc.gov/nchs/FASTATS/pneumonia.htm. Accessed August 2012.

2.Muller LM, Gorter KJ, Hak E, Goudzwaard WL, Schellevis FG, Hoepelman AI, Rutten GE: Increased risk of common infections in patients with type 1 and type 2 diabetes mellitus. Clin Infect Dis 41:2810288, 2005

3.Shah BR, Hux JE: Quantifying the risk of infectious diseases for people with diabetes. Diabetes Care 26: 510-513, 2003

4.Fry AM, Shay DK, Holman RC, Curns AT, Anderson LJ: Trends in hospitalizations for pneumonia among persons aged 65 years or older in the United States, 1988-2002. JAMA 294: 2712-2719, 2005

5.Thomsen RW, Riis A, Norgaard M, Jacobsen J, Christensen S, McDonald CJ, Sorensen HT: Rising incidence and persistantly high mortality of hospitalized pnuemonia: a 10-year population-based study in Denmark. J Intern Med 259: 410-417, 2006

6.Green A, Christian HN, Pramming SK: The changing world demography of type 2 diabates. Diabetes Metab Res Rev 19: 3-7, 2003

7.Kornum JB, Thomsen RW, Riis A, et al: Diabetes, glycemic control, and risk of hospitalization with pneumonia: A population based case-control study. Diabetes Care 31: 1541-1545, 2008

8.Chen LK, Peng LN, Lin MH, Lai HY, Lin HC, Hwang SJ: Diabetes mellitus, glycemic control, and pneumonia in long-term care facilities: a 2-year prospective cohort study. J Am Med Dir Assoc 12: 33-37, 2011

9.Pozzilli P, Leslie RD: Infections and diabetes: mechanisms and prospects for prevention. Diabet Med 11:935–941, 1994

INTRODUCTION

Variable Normal HbA1c (n+33)

Abnormal HbA1c (n=37)

P-value

Severe CAP (PSI IV/V)

20 (61%) 17 (46%) 0.220

Time to clinical stability (≥8 days)

3 (9%) 8 (22%) 0.150

In hospital mortality

1 (3%) 4 (11%) 0.207

Both pneumonia and Diabetes mellitus (DM) pose as important causes of morbidity and mortality. In 2009, 1.1 million people in the U.S. were hospitalized with pneumonia in the U.S. More than 50,000 people died from the infection, making it the 8th leading cause of death. Diabetes mellitus affects 25.8 million individuals in the US, diagnosed and undiagnosed, and was the 7th leading cause of death in 2009.1 In diabetics, the 3rd most common diagnoses for hospitalization is respiratory diseases.1 Diabetics are known to have more complications compared to their non-diabetic counterparts including

risk of hospitalization from CAP. 2,3

Admission hyperglycemia is known to be an independent risk factor of adverse events, even in non-diabetics. However, the admission hyperglycemia represents a static measurement of blood glycemia and is confounded by the stress response initiated by the infection. Thus it is unknown if long term glycemic control plays a role in the development of adverse events in diabetics admitted with CAP. HbA1c (glycosylated hemoglobin) is routinely used as a measurement of glucose control for the past 3 months as the degree of glycosylation of hemoglobin depends upon long term blood sugars levels. Given the rising incidence of pneumonia related hospitalizations 4,5 and the increasing prevalence of diabetes 6, it is important to clarify whether diabetes and poor long-term glycemic control is a risk factor for poor outcomes.

The objective of this study was to compare the severity and clinical outcomes of CAP in patients with DM with and without long term glycemic control, represented by HbA1c.

The presence of a new pulmonary infiltrate on chest radiograph at the time of admission + one of the following:

1. New or increased cough

2. Abnormal temperature (<35.6°C or >37°C)

3. An abnormal leukocyte count (10,500 cells/µL or <4,500 cells/µL or bands >5%

CONCLUSIONRESULTS

A total of 70 patients were included in the study. Normal glucose control (HbA1c level <7) was found in 33 patients, and abnormal in 37 patients. Both groups of patients showed no statistically significant differences in severity of clinical outcomes. Results can be found in Graphs 1-3

Graph 1

Graph 2

Graph 3