|Year : 2015 | Volume
| Issue : 4 | Page : 228-231
Effect of glycemic control on the severity and outcome of stroke in Saudi Arabia
Magdy A Mostafa MD 1, Nevine A Mohamed2
1 Department of Neurology, Ain Shams University, Cairo, Egypt; Department of Neurology, King Abdulaziz Hospital, Mecca, Kingdom of Saudi Arabia
2 Department of Clinical Pathology, Ain Shams University, Cairo, Egypt
|Date of Submission||30-Apr-2015|
|Date of Acceptance||26-Jun-2015|
|Date of Web Publication||27-Nov-2015|
Magdy A Mostafa
Department of Neurology, King Abdulaziz Hospital, Mecca, Kingdom of Saudi Arabia
Source of Support: None, Conflict of Interest: None
Diabetes mellitus (DM) is a well-known risk factor of ischemic stroke. However, the effect of glycemic control regardless of the presence of DM on the clinical picture of stroke and its impact on the severity and outcome of stroke is not fully investigated.
The aim of this study was to assess the impact of prestroke glycemic control regardless of the presence of past history of DM on the size of infarction, stroke severity, and functional outcome in patients with acute ischemic stroke.
Patients and methods
We measured glycosylated hemoglobin (HbA1c) level as an indicator for glycemic control in the last 3 months before stroke in 56 patients with the diagnosis of the first attack of acute ischemic stroke. There were 26 female and 30 male patients between 45 and 94 years of age. After history taking and full clinical examination, the size of infarction was measured using computed tomography scan of the brain. Stroke severity within 72 h from onset of symptoms was assessed using the National Institute of Health Stroke Scale and outcome of stroke after 2 months was assessed using the modified Barthel Index, both of which were assessed for each stroke patient.
There was a significant positive correlation between the value of HbA1c and both the size of infarction and National Institute of Health Stroke Scale score assessed within 72 h from symptom onset (P < 0.01). In contrast, increased HbA1c value was significantly associated with a decrease in the modified Barthel Index score assessed after 2 months (P < 0.001).
Glycemic control has a significant effect on ischemic stroke severity and outcome.
Keywords: glycemic control, outcome of stroke, glycosylated hemoglobin
|How to cite this article:|
Mostafa MA, Mohamed NA. Effect of glycemic control on the severity and outcome of stroke in Saudi Arabia. Egypt J Neurol Psychiatry Neurosurg 2015;52:228-31
|How to cite this URL:|
Mostafa MA, Mohamed NA. Effect of glycemic control on the severity and outcome of stroke in Saudi Arabia. Egypt J Neurol Psychiatry Neurosurg [serial online] 2015 [cited 2018 Dec 16];52:228-31. Available from: http://www.ejnpn.eg.net/text.asp?2015/52/4/228/170652
| Introduction|| |
Diabetes mellitus (DM) is a well-established independent risk factor for stroke, and this increased risk has been linked to the pathophysiological changes seen in the cerebral vessels of patients with diabetes. Several studies showed that patients with diabetes who develop stroke have a less-favorable outcome compared with those without  .
Glycosylated hemoglobin A1c (HbA1c) reflects mean ambient fasting and postprandial glycemia over a 2-3-month period. Although HbA1c testing is mainly used for monitoring blood sugar control in patients with diabetes, the WHO now recommends that HbA1c can be used as a diagnostic test for diabetes. A value of HbA1c of 6.5% is recommended as the cutoff point for diagnosing diabetes. For patients with DM, the goal of therapy is less than 7.0%. One advantage of using HbA1c for diagnosis is that the test does not require a fasting blood sample  . Some studies suggested that the individuals, both with and without DM, with an elevated HbA1c have a higher rate of microvascular complications  .
However, it is still unclear whether stroke features, severity, and prognosis differ according to glycemic control. Although several studies compared the patients on the basis of the clinical prestroke diagnosis of DM, no evaluation of HbA1c in the whole study cohort was available. As a result, there could have been interference from patients with subclinical DM who were included in the group without a diagnosis of DM  .
| Aim of work|| |
The aim of this study was to study the effect of prestrike glycemic control (HbA1c) regardless of past history of DM on the size of infarction, severity of clinical picture, and outcome in ischemic stroke patients.
| Patients and methods|| |
This study was conducted on 56 patients with the diagnosis of ischemic stroke. The patients were recruited from King Abdulaziz Hospital in Mecca. The only inclusion criterion was the confirmed diagnosis of first ischemic stroke with onset of symptoms in the last 72 h before admission. The following exclusion criteria were applied:
- Age below 40 years;
- Negative computed tomographic (CT) scan of the brain both on admission and on follow-up;
- Presence of hepatic or renal failure; and
- Presence of medical conditions that may affect the level of HbA1c, such as anemia, hemoglobinopathies, pregnancy, and alcoholism.
All patients were subjected to full clinical assessment including history taking and full general and neurological examination. CT scan of the brain was performed for each patient to exclude intracranial hemorrhage and to diagnose cerebral infarction. If CT scan was negative, it was repeated after 72 h. The size of the lesion was calculated according to the formula 0.5 × A × B × C [where A and B are the largest perpendicular diameters measured on CT and C is the slice thickness (10 mm)]. All scans were performed on Siemens Somaton Balance scanner (Siemens Company, Germany). Full laboratory investigation was carried out, including complete blood count, renal function tests, liver function tests, coagulation profile, and lipid profile including serum cholesterol, HDL, LDL and triglycerides. HbA1c was evaluated for each patient using high performance liquid chromatography with a cation exchanger. In addition, ECG, transthoracic echocardiography, and carotid duplex were performed as part of stroke workup. Stroke severity within 72 h from onset of symptoms was assessed for each patient using the National Institute of Health Stroke Scale (NIHSS). In addition, stroke outcome after 2 months from admission was assessed for each patient using the modified Barthel Index.
IBM SPSS statistics (version 22.0, 2013; USA) was used for data analysis. Data were expressed as median and percentiles for quantitative nonparametric measures. The ranked Spearman correlation test was used to study the possible association between two variables for nonparametric data. The probability of error at 0.05 was considered significant, whereas at 0.01 and 0.001 it was considered highly significant.
| Results|| |
Fifty-six patients diagnosed with acute ischemic stroke were studied [26 female (46%) and 30 male (54%) patients]. Their ages ranged from 45 to 94 years with a median value of 63.5 years. The presence of past history of DM in each patient was assessed. Positive past history of DM was found in 32 stroke patients (57%), whereas 24 patients (43%) were free of diabetic history. CT scan of the brain was used to measure the size of infarction. HbA1c was measured as indicator for the state of glycemic control in the last 3 months before onset of stroke. NIHSS score was calculated for each patient within the first 72 h from onset of symptoms, and functional outcome after 2 months was assessed using the modified Barthel Index. The range, median value, and the 25th and the 75th percentiles for each parameter are presented in [Table 1].
On studying the possible association between the value of HbA1c and the infarction size, there was a significant positive correlation between HbA1c value and size of infarction among all cases (r = 0.489, P < 0.001); the same relation was present between HbA1c value and NIHSS score (r = 0.385, P < 0.003). In contrast, there was a significant negative association between HbA1c value and modified Barthel Index score (r = −0.350, P < 0.001) ([Figure 1], [Figure 2], [Figure 3]).
|Figure 1 Correlation between HbA1c and size of infarction (P < 0.05). HbA1c, glycosylated hemoglobin|
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|Figure 2 Correlation between HbA1c and National Institute of Health score (NIHSS) (P < 0.05). HbA1c, glycosylated hemoglobin|
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|Figure 3 Correlation between HbA1c and Barthel Index score (P < 0.05). HbA1c, glycosylated hemoglobin|
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As regards age, serum cholesterol, HDL, LDL, and serum triglycerides, there was no significant correlation between any of them and the infarction size. In addition, no significant correlation was found with either NIHSS or modified Barthel Index scores.
| Discussion|| |
Hyperglycemia in relation to acute ischemic stroke is common both in patients with and in patients without a diagnosis of DM. It has been suggested to worsen survival. However, recent results from several clinical studies indicate that, in particular, patients with stroke and stress hyperglycemia, but not diabetes, have increased mortality ,, . In contrast, earlier studies found that patients with acute ischemic stroke and similar glucose concentrations had similar outcome regardless of whether or not they had diabetes  .
In this study, the role of HbA1c was systematically evaluated with respect to severity and outcome after ischemic stroke regardless of whether or not patients had DM. Thus, the effect of stress hyperglycemia is eliminated. In this work, we found a strong relationship between prestroke glycemic control and neurological outcome. HbA1c was a good independent predictor of stroke severity in the whole study group, not only in patients with DM. Our results demonstrate that poor prestroke glycemic control is an independent determinant of stroke severity; moreover, it is a robust marker of neurological functional outcome. These results are supported by the effect of HbA1c value on the infarction size.
Results from three newly published studies ,, also show that high HbA1c is independently associated with poor outcome 1 year after stroke, supporting our findings. Nevertheless, one of the studies, based on data from the Fukuoka Stroke Registry  , only included patients with known DM; moreover, only one of these studies investigated the effect of HbA1c on acute stroke severity  .
In the previous study, stress hyperglycemia was related to increased mortality, but it lost its predictive value when the analysis was adjusted for prestroke glycemic control. Moreover, stress hyperglycemia was not correlated with stroke severity in an independent manner. In addition, it did not influence the functional outcome 1 year after stroke  . These findings support the importance of the use of HbA1c indicating the state of prestroke glycemic control over glucose tolerance curve as prognostic marker of stroke severity and outcome.
The exact mechanism by which poor prestroke glycemic control affects survival of stroke patients is less clear. General complications related to poorly controlled DM could be one explanation. An increased HbA1c level reflects poor long-term glycemic control and has specific implications for the structure and function of the vascular bed, including small and large cerebral vessels. Increased HbA1c level might also be a marker of poor compliance, indicating an unhealthy lifestyle.
In contrast, Murros and colleagues found that prestroke blood glucose level, unlike poststroke blood glucose level, did not have any predictive value concerning stroke outcome. In this study, the case fatality rate, severity of hemiparesis, functional outcome, and infarct size did not differ according to the state of prestroke glycemic control, but fasting blood glucose level of the nondiabetic patients was correlated strongly with the severity of hemiparesis and predicted stroke outcome. Therefore, it was concluded that high fasting blood glucose values after stroke reflect a stress response to a more severe ischemic brain lesion  .
This is in agreement with some relatively recent randomized controlled trials ,, , which have found that intensive glycemic control could not reduce cerebrovascular risk in diabetic patients, but it is important to highlight that all these studies used a cutoff HbA1c higher than 6.4%. Therefore, additional studies are needed to elucidate whether intensified prestroke glycemic control may improve clinical course and outcome in patients with acute ischemic stroke.
One of the limitations of this study is that it did not distinguish between different types of ischemic stroke and so the results of this study cannot be specified. It is well-known that certain types of ischemic stroke are more related to the diabetic history. Another limitation is related to the lack of data on the duration of diabetes and serial measurements of the HbA1c during the follow-up period.
| Conclusion|| |
Measurement of HbA1c in every ischemic stroke patient is very important even if the patient is not known to be diabetic because the prestroke glycemic control is a predictor of stroke severity and outcome.
The author gratefully acknowledges several colleagues and technicians in the laboratory of King Abdulaziz Hospital, Mecca, Saudi Arabia, for their help and technical support.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]