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Determination of Risk Factors for Mortality in Elderly Patients w
Emergency Medicine: Open Access

Emergency Medicine: Open Access
Open Access

ISSN: 2165-7548

+44 1223 790975

Research Article - (2018) Volume 8, Issue 4

Determination of Risk Factors for Mortality in Elderly Patients with Hypoglycemia

Sema Avcı1*, Ali Bilgin1 and Fatih Büyükcam2
1Department of Emergency Medicine, Sabuncuoğlu Şerefeddin Research and Training Hospital, Amasya University, Amasya, Turkey
2Department of Emergency Medicine, Istanbul Memorial Ataşehir Hospital, Istanbul, Turkey
*Corresponding Author: Sema Avcı, Department of Emergency Medicine, Sabuncuoğlu Şerefeddin Research and Training Hospital, Amasya University, Amasya, Turkey, Tel: 0 530 843 1363 Email:

Keywords: Hypoglycemia; Elderly; Emergency; Risk factor; Mortality

Introduction

Hypoglycemia is commonly defined as random blood glucose level less than 70 mg/dL or 3.9 mmol/L however investigators use hypoglycemia thresholds ranging from 3 to 3.9 mmol/L (1,2). Widely known, Whipple triad is used to describe hypoglycemia which including a) low blood glucose level: b) symptoms and signs accompanying low blood glucose level: c) improvement of symptoms with elevated blood glucose level [1]. The incidence of hypoglycemia in the literature differs due to definitions, the age of the population and treatment modalities and also it is difficult to estimate hypoglycemic elderly patients’ incidence (older >75 years) [2]. While many hypoglycemia periods are asymptomatic, serious acute complications such as seizure, coma and cardiac arrhythmias may occur [2]. In older people, severe hypoglycemia may lead to serious acute vascular events such as myocardial infarction, acute cardiac decompensation, stroke, ventricular arrhytmias, increased morbidity and mortality [2]. Elderly patients with diabetes mellitus particularly are prone to hypoglycemic periods [3]. Studies have been showed that severe hypoglycemia is a risk factor for lower quality life and cause of mortality [3].

The following study was performed to determine the risk factors for mortality in elderly patients with hypoglycemia in ER. The results from this study will inform to physicians about earlier predicting of geriatric mortality.

Material and Methods

Study design

We conducted a retrospective cross-sectional study based on the patients’ records admitted to emergency service in Amasya University Sabuncuoğlu Şerefeddin Research and Training Hospital, Amasya, Turkey. The study protocol was approved by Amasya Provincial Health Directorate and no ethical approval was needed because of retrospective design and as only registry data was used.

We included all patients in the Amasya University Sabuncuoğlu Şerefeddin Research and Training Hospital Emergency Service and with measured hypoglycemia during the dates January 2012 to December 2016. These are the definitions of hypoglycemia according to American Diabetes Association (ADA): Level 1: Blood glucose level is 3.9 mmol/l (70 mg/dl) or less. Level 2: Blood glucose level of <3.0 mmol/l (<54 mg/ dl) is adequately low, clinically important hypoglycemia. Level 3: Severe hypoglycemia, indicates serious cognitive impairment demanding support for recovery. Also International Study Group suggests that level of blood glucose <3.0 mmol/l (<54 mg/dl) be defined as clinicaly important hypoglycemia. We studied serious hypoglycemia group of plasma glucose <3.0 mmol/l (<54 mg/dl) according to American Diabetes Association and International Study Group [4].

Age, sex, laboratory parameters, coexisting DM, using OAD and insulin, co-morbidities, admission time to hospital, admission results, 15-day and 3-month mortality data were obtained from the patients’ records.

Statistical analysis

Parameters were analysed with SPPS for Windows 23.0 version. The mean of the continuous variables in descriptive statistics was expressed with standard deviation; categorical variables were expressed with numbers and percentages. The significance of the difference between the groups was evaluated with Chi-Square Test. Mann-Whitney U Test was used in comparison of binary groups. Kruskal Wallis Test was used in comparison of groups more than two. p<0.005 value was accepted to be statistically significant.

Results

A total of 111 hypoglycemia episodes in elderly patients (>65 years) from 912.500 emergency department cases were recorded during about five-year study period, which was 0.012% of all patients admitted to emergency department. The average age of the patients was 76,2 ± 6,6 and 63.1% (n=70) of patients were female (Tables 1 and 2).

  Mean ± SD / n(%)
Glucose (mg‎/dL) 37.5 ± 10
BUN 63.5 ± 47.8
Creatinin 1.72 ± 1.33
Na (sodium) 141.5 ± 26.9
K (potassium) 4.56 ± 1.03
Ca (calcium) 8.55 ± 1.17
Hemoglobin (mg/dL)(HGB) 11.9 ± 2.3
Hematocrit (HTC) 36.9 ± 7.6
PLT (10^3) 223.5 ± 100
MPV(mean platelet volume) 8.5 ± 1.7
RDW 16.37 ± 2.88
Neutrophile 7.4 ± 4.6
Lymphocyte 2.2 ± 2

Note: 63.1% (n=70) of patients had DM, 51.4% (n=57) of patients were using OAD and 21.6% (n=24) of patients were using insulin.

Table 1: Complete blood count and biochemical parameters of patients.

  Mean ± SD / n(%)
Admission time
24:00-04:00 15 (13.5%)
04:00-08:00 10 (9%)
08:00-12:00 17 (15.3%)
12:00-16:00 14 (12.6%)
16:00-20:00 27 (24.3%)
20:00-24:00 28 (25.2%)
Co-morbidities
Asthma 2 (1.8%)
COPD 12 (10.8%)
CAD 41(36.9%)
Renal failure 14 (12.6%)
HT 69 (62.2%)
CAD 18 (16.2%)
Malignancy 7 (6.3%)
Others 10 (9%)
Admission results
Discharge 66 (59.5%)
Hospitalization in services 20 (18%)
Hospitalization in intensive care unit 22 (19.8%)
Exitus 3 (2.7%)
Mortality
15-day 21 (18.9%)
3-month 3 (3.3%)

Table 2: Admission time, co-morbidities, admission results and mortality rates of patients.

The most common admission hours were 20.00-24.00 (25.2%). HT was the most common concomitant disease among with hypoglycemic geriatric patients. 66% of patients were discharged from ER after the treatment. 15-day mortality was higher than 3-month mortality (Table 3).

  3-month mortality 15-day mortality
Present Absent p Present Absent p
Glucose (mg‎/dL) 43.3 ± 7.2 38.5 ± 9.5 0.380 32.5 ± 10.9 38.7 ± 9.4 0.014
BUN 62.7 ± 21.5 55.2 ± 37.1 0.369 97.9 ± 71.1 55.5 ± 36.6 0.002
Creatinin 1.98 ± 1.14 1.41 ± 0.69 0.166 2.99 ± 2.34 1.43 ± 0.7 <0.001
Na 137.3 ± 4.2 138.8 ± 5.6 0.513 153.4 ± 60.4 138.8 ± 5.5 0.812
K 4.77 ± 0.78 4.44 ± 0.92 0.411 5.02 ± 1.36 4.45 ± 0.91 0.094
Ca 8 ± 0.79 8.8 ± 0.79 0.054 7.61 ± 1.88 8.77 ± 0.8 0.006
HGB (mg/dL) 11.1 ± 0.9 12.1 ± 2 0.317 11.2 ± 3.4 12 ± 2 0.265
HTC 36.8 ± 1.4 37.2 ± 7 0.661 35.4 ± 10.2 37.2 ± 6.9 0.431
PLT 267 ± 27.8 237.3 ± 99.8 0.363 160 ± 81.7 238.3 ± 98.4 0.001
MPV 8.5 ± 1.4 8.4 ± 1.7 0.893 9 ± 1.5 8.4 ± 1.7 0.105
RDW 17.9 ± 2.52 15.66 ± 2.07 0.101 19.07 ± 4.05 15.74 ± 2.11 <0.001
Neutrophile 14.3 ± 3.6 6.6 ± 4.1 0.012 10.1 ± 4.8 6.8 ± 4.3 0.002
Lymphocyte 0.8 ± 0 2.2 ± 1.9 0.007 2.2 ± 2.6 2.2 ± 1.9 0.052

Table 3: Relationship between mortality and laboratory parameters.

The blood glucose levels of the patients who died within the first 15 days after admission were significantly lower than the patients who did not die (p=0.014). BUN and creatinine values were significantly higher in patients who died within the first 15 days after admission (p=0.002, p=<0.001). Blood calcium level and PLTs were significantly lower in patients who died within the first 15 days (p=0.006; p=0.001). RDW was significantly higher in patients who died in the first 15 days (p=<0.001). Neutrophile count was significantly higher in both group patients who died within 15 days and 3 months (p=0.002; p=0.012). Lymphocyte count was significantly lower in patients who died within 3 months (p=0.007) (Table 4).

  Mortality in 3 months Mortality in 15 days
Present Absent p Present Absent p
Age (years) 72.7 ± 2.1 76.3 ± 6.6 0.290 76.1 ± 6.9 76.2 ± 6.6 0.752
Gender
Female 2 (66.7%) 57 (65.5%) 0.728 11(52.4%) 59(65.6%) 0.26
Male 1 (33.3%) 30 (34.5%) 10(47.6%) 31(34.4%)
Admission time
24:00-04:00 - 13 (14.9%) 0.702 2 (9.5%) 13(14.4%) 0.558
04:00-08:00 - 8 (9.2%) 2 (9.5%) 8 (8.9%)
08:00-12:00 2 (66.7%) 10 (11.5%) 5 (23.8%) 12(13.3%)
12:00-16:00 - 11 (12.6%) 3 (14.3%) 11(12.2%)
16:00-20:00 1 (33.3%) 19 (21.8%) 7 (33.3%) 20(22.2%)
20:00-24:00 - 26 (29.9%) 2 (9.5%) 26(28.9%)
Co-morbidities and others
DM 2 (66.7%) 62 (71.3%) 0.645 6 (28.6%) 64(71.1%) <0.001
OAD 1 (33.3%) 51 (58.6%) 0.383 5 (23.8%) 52(57.8%) 0.005
Insulin 1 (33.3%) 21 (24.1%) 0.573 2 (9.5%) 22 (24.4%) 0.237
Co-morbidity 3 (100%) 76 (87.4%) 0.673 18 (85.7%) 79 (87.8%) 0.726
Asthma - 2 (2.3%) 0.934 - 2 (2.2%) 0.656
COPD - 10 (11.5%) 0.699 2 (9.5%) 10 (11.1%) 0.596
CAD 2 (66.7%) 36 (41.4%) 0.383 3 (14.3%) 38 (42.2%) 0.017
Renal failure 1 (33.3%) 8 (9.2%) 0.274 5 (23.8%) 9 (10%) 0.136
HT 2 (66.7%) 61 (70.1%) 0.662 6 (28.6%) 63 (70%) 0.001
CAD 1 (33.3%) 16 (18.4%) 0.471 1 (4.8%) 17 (18.9%) 0.187
Malignancy - 3 (3.4%) 0.902 4 (19%) 3 (3.3%) 0.023
Others - 7 (8%) 0.782 3 (14.3%) 7 (7.8%) 0.396
Admission result
Discharge 1 (33.3%) 64 (73.6%) 0.475 1 (4.8%) 65 (72.2%) <0.001
Service 2 (66.7%) 17 (19.5%) 1 (4.8%) 19 (21.1%)
Critical care - 3 (3.4%) 19 (90.5%) 3 (3.3%)
Exitus - 3 (3.4%) - 3 (3.3%)

Table 4: Relationship between mortality and demograhy, admission time, co-morbidities, admission result.

Concomitant DM disease and to use OAD were statistically significant in patients who died within 15 days (p=<0.001; p=0.005). The presence of coexisting CAD, HT and malignancy was significant in those who die within the first 15 days (p=0.017; p=0.001; p=0.023). The relationship between the outcome of the patients and the 15-day mortality was statistically significant (p<0.001).

Discussion

In our study, low glucose, high creatinin and BUN levels were found risk factors for 15-day mortality.

As it is well known, renal disability is an independent risk factor for severe hypoglycemia because metabolization of circulating insulin, reabsorbtion of filtered glucose, a portion of gluconeogenesis, excretion of drugs and metabolization of OAD are some functions of kidneys [5]. Renal impairment causes reduction of the excretion of hypoglycemic agents, the degradation of insulin in peripheral tissues and reduction of the gluconeogenesis [5]. In healthy individuals, the kidney and liver make an equal contribution to gluconeogenesis and glucose releasing into the circulation during the hypoglycemia [5]. In Moen’s comprehensive study, chronic renal disease in hypoglycemic patients was a risk factor for 1-day mortality [6]. Age could predict 1-year mortality in hypoglycemic patients but severity of hypoglycemia could not predict the mortality [7]. Since we received geriatric patients in our study, we investigated risk factors for short-term mortality rather than long-term. In median survival time after discharge was significantly shorter in patients with severe hypoglycemia compared to patients with moderate hypoglycemia [8]. According to our results, short term mortality is higher because severe hypoglycemia and impaired renal function cause more severe acute vascular events in elderly patients.

We found that low calcium level is associated with 15-day mortality of geriatric patients. As known, calcium is an important electrolyte for biological circulations such as membrane potential, hormone secretion, cardiac otomaticity, enzyme activity, extraction-contraction for muscles, synaptic transmission, neuronal conduction and mitosis [9,10]. The impaired parathyroid hormone secretion or action, impaired vitamin D synthesis or action, calcium chelation or precepitation may result in hypocalcemia [11]. Hypocalcemia may causes cardiovascular and neuromuscular insuffiency [11]. Deficiency of calcium concentrations are common in patients have critical illness and reduced plasma calcium level increases the mortality especially in these patients [9,12]. An older patient with comorbidity who presented to ER with hypoglycemia may be considered as a critical patient. Cardio-neurovascular insufficiency caused by hypocalcemia in a critical patient may be a reason of earlier mortality.

It has been demonstrated that high RDW values are associated with increased mortality in general population and particularly patients with cardiovascular disease, acute kidney injury, COPD, hepatitis, congestive heart failure, acute stroke, pulmonary embolism and septic shock [13,14]. RDW is a part of the complete blood count that shows heterogeneity of the red blood cell size [13]. The reason for increased RDW, which has an important role in the differential diagnosis of anemia, is not clear [13,14]. It is known that advanced age and inflammatory process may increase RDW [13,14]. Increased RDW, advanced age, concomitant illness, diabetes and dementia may also predict earlier mortality [14,15]. The high level of RDW in elderly patients is associated with earlier mortality in accordance with the literature.

Reduced PLTs were another risk factor for earlier mortality in elderly patients according to our study. It is shown that PLTs and functions have changes age-related, hematopoietic tissue-related and bloodvascular health [16]. PLTs are stable until middle ages, but they decrease in later ages and effect of aging on PLT functions is not clear [16]. PLTs play an important role in hemostasis and pathological processes of atherosclerosis and arterial thrombosis [17]. The relationship between thrombocytopenia or thrombocytosis and mortality differs in studies. Thrombocytopenia and thrombocytosis were associated with mortality in elderly patients [17] elderly patients, PLTs were not associated with vascular outcomes but low and high PLTs were associated with noncardiovascular mortality including cancer mortality [18]. Low or high level of PLTs may cause vascular events.

In our study, high neutrophile count was a risk factor for both 15- day and 3-month mortality and low lymphocyte count was a risk factor for 3-month mortality. Briefly, increased neutrophiles and decreasing lymphocytes were important for predicting 3-month mortality. Neutrophiles demonstrate the immediate host response to fungal and bacterial infections, which are commonly responsible for the increased rates of mortality and morbidity, particularly in the older patients [19]. In addition, the number of impaired neutrophiles in diabetic patients may increase the severity of infection [20]. The lower lymphocyte count was a prognostic factor in adults affected by cardiovascular diseases, malignancy and renal insufficieny [21]. Mortality data according to the peripheral blood count parameters differ in the literature.

Nowadays, diabetes is a global health problem and it is the most common reason of mortality due to cardiovascular disease (CVD) [22]. Pharmacotherapy is the main method to administer for diabetic patients by controlling hemoglobin A1c, which is substantial to reduce the risk of cardiovascular events and early mortality [22]. OAD may reduce blood glucose levels while exerting some beneficial effect on CVD risk factors [23]. The potential role of OAD may have on CVD risk is an controversial subject [23]. The blood glucose-lowering effects of OAD and their effects on vasculature and the heart is not clear [23]. OAD associated hypoglycemia was not related to patients with increased mortality risk [24]. In their study, hypoglycemia-associated mortality was not OAD-associated but related to patients with comorbidities [24]. We think that having an additional disease in elderly patients are factors that worsen the current situation.

Conclusion

In conclusion, low glucose level, impaired renal function, low calcium level, high RDW, low platelet count, high neutrophile counts, to use OAD, presence of DM and to have comorbidities such as CAD, HT, malignancy are risk factors for earlier mortality in elderly patients. Nonetheless, these findings must be supported by further studies.

Limitation

The major limitations of the present study are the small sample size of the included patients, lack of the control group, single center experience.

Conflict of Interests

The authors declare no conflict of interests.

References

  1. Sircar M, Bhatia A, Munshi M (2016) Review of Hypoglycemia in the Older Adult: Clinical Implications and Management. Can J Diabetes 40: 66–72.
  2. Abdelhafiz AH, Rodríguez-Mañas L, Morley JE, Sinclair AJ (2015) Hypoglycemia in Older People - A Less Well Recognized Risk Factor for Frailty. Aging Dis 6: 156-167.
  3. Vihonen H, Kuisma M, Nurmi J (2018) Hypoglycemia without diabetes encountered by emergency medical services: a retrospective cohort study. Scand J Trauma Resusc Emerg Med 26: 12.
  4. http://www.diabetes.org/newsroom/press-releases/2016/ada-issues-hypoglycemia-position-statement.html 25.08.2018.
  5. Yun JS, Ko SH (2016) Risk Factors and Adverse Outcomes of Severe Hypoglycemia in Type 2 Diabetes Mellitus. Diabetes Metab J 40: 423-432.
  6. Moen MF, Zhan M, Hsu VD, Walker LD, Einhorn LM, et al. (2009) Frequency of Hypoglycemia and Its Significance in Chronic Kidney Disease. Clin J Am Soc Nephrol 4: 1121-1127.
  7. Elwen FR, Huskinson A, Clapham L, Bottomley MJ, Heller SR, et al. (2015) An observational study of patient characteristics and mortality following hypoglycemia in the community. BMJ Open Diabetes Research and Care 3: e000094.
  8. Akirov A, Grossman A, Shochat T, Ilan Shimon I (2017) Mortality Among Hospitalized Patients With Hypoglycemia: Insulin Related and Noninsulin Related. J Clin Endocrinol Metab 102: 416–424.
  9. Zaloga GP (1986) Chernow Bart. Hypocalcemia in Criticall Illness. JAMA 256: 1924-1929.
  10. Kelly A, Levine MA (2013) Hypocalcemia in the critically ill patient. J Intensive Care Med 28: 166-177.
  11. Zaloga GP (1992) Hypocalcemia in critically ill patients. Crit Care Med 20: 251-262.
  12. Steele T, Kolamunnage-Dona R, Downey C, et al. Assessment and clinical course of hypocalcemia in critical illness. Critical Care 17: 106.
  13. Periša V, Zibar L, Sinčić-Petričević J, Knezović A, Periša I, et al. (2015) Red blood cell distribution width as a simple negative prognostic factor in patients with diffuse large B-cell lymphoma: a retrospective study. Croat Med J 56: 334-343.
  14. Karataş M, Özyurt S (2017) Is elevated red blood cell distribution associated with mortality in superelderly patients with community-acquired pneumonia?. Biomedical Research 28: 4342-4347.
  15. Temiz A, Das M (2018) Association Between Admission Red Cell Distribution Width and Mortality in Elderly Hip Fracture Patients: A Retrospective Case Control Study. EJMI 2: 29–34.
  16. Jones CI (2016) Platelet function and ageing. Mamm Genome 27: 358–366.
  17. Msaouel P, Lam AP, Gundabolu K, Chrysofakis G, Yu Y, et al. (2014) Abnormal platelet count is an independent predictor of mortality in the elderly and is influenced by ethnicity. Haematologica 99: 930-936.
  18. Bom JG, Heckbert SR, Lumley T,  Holmes CE, Cushman M, et al. (2009) Platelet count and the risk for thrombosis and death in the elderly. J Thromb Haemost 7: 399-405.
  19. Butcher S, Chahel H, Lord M (2000) Ageing and the neutrophile: no appetite for killing?. Immunology 100: 411-416.
  20. Hillson R (2015) Diabetes and the blood – white cells and platelets. Practical Diabetes.
  21. Marengoni A, Petroboni B, Casella S, Martinelli D, Cossi S (2008) Total lymphocyte count and in-hospital mortality in older persons with multimorbidity. Aging Clin Exp Res 20: 290-296.
  22. Goyat R, Thornton JD, Tan X, Kelley GA (2017) Cardiovascular mortality and oral antidiabetic drugs: protocol for a systematic review and network meta-analysis. BMJ Open 7: e017644.
  23. Bianchi C, Miccoli R, Daniele G, Penno G, Del Prato S (2009) Is There Evidence That Oral Hypoglycemic Agents Reduce Cardiovascular Morbidity/Mortality? Yes. Diabetes Care 32: 342-S348.
  24. Boucai L, Southern WN, Zonszein J (2011) Hypoglycemia-associated Mortality Is Not Drug-associated but Linked to Comorbidities. Am J Med 124: 1028-1035.
Citation: Avcı S, Bilgin A, Büyükcam F (2018) Determination of Risk Factors for Mortality in Elderly Patients with Hypoglycemia. Emergency Med 8: 380.

Copyright: © 2018 Avcı S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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