Introduction
Diabetes mellitus (DM) is a chronic metabolic disease which results from diminished or absent secretion of insulin or even by reduced tissue sensitivity to insulin (Report of WHO Consultation, 1999;1 International Diabetes Federation, 2015; American Diabetes Association, 2016).2 Diabetes is a global endemic with rapidly increasing prevalence in developing countries such as Nigeria. Type 2 diabetes mellitus is one of the leading causes of preventable death in the world, with stroke, myocardial infarction and other cardiovascular diseases being the most common causes of death for adults with diabetes (Newman et al., 2017).3 A number of factors including less glycemic control, smoking, high blood pressure, elevated cholesterol levels, obesity, and lack of regular exercise are considered to be risk factors that accelerate the deleterious effects of diabetes (Elfaki et al., 2014).4 According to International Diabetes Federation (IDF), in 2017, approximately 425 million adults were living with diabetes and it is estimated to affect up to 629 million people by the year 2045 (IDF, 2017).5 Diabetes Mellitus has become a major public health problem in Nigeria accounting for a prevalence of 2.4% with total number of mortality amounting to 3028 deaths in 2017 (IDF, 2017).5 In the world, WHO estimates that, globally, 422 million adults aged over 18 years were living with diabetes in 2014 accounting for a prevalence of 8.5% among the adult population (WHO, 2016).6 Therefore, this continued increase in the prevalence of diabetes globally has become a matter of great concern, and hence, the management of diabetic complications is particularly important. (Yang et al., 2010; Danaei et al., 2011; Soriguer et al., 2012). 7,8,9
In individuals diagnosed of diabetes mellitus, glucose monitoring is essential for glycemic control (Yoon et al., 2015). Also, in diabetes mellitus, compared with non-diabetes, glycation of various proteins is known to be increased, and some of these glycated proteins are thought to be involved in the onset and progression of chronic diabetic complications (Cohen, 1998).10 Currently, the laboratory tests used to diagnose Diabetes Mellitus are glycated hemoglobin (A1C), fasting plasma glucose (FG) and two-hour plasma glucose (2hG) after a 75g oral glucose tolerance test (OGTT) (Sacks et al., 2011; ADA, 2016).11 Of the glycemic indices, the American Diabetes Association recommends glycated hemoglobin (HbA1 c) testing in all diabetic patients as an initial assessment and then as a part of continuing care (ADA, 2014). 12
This recommendation is derived from clinical data that shows that HbA1 c reflects average glycemicstatus over 2-3 months and predicts diabetic complications (Lee et al., 2013). 13
Albumin is one of the most abundant plasma proteins (Tiwari et al., 2015).14 The glycation of albumin to form glycated albumin (GA) is ten times more than the glycation of hemoglobin in type 2 DM (Tahara et al., 1995).15 GA is a marker reflects a short-term glycemic control (Yoon et al., 2015).16 One advantage of utilizing serum albumin as a measure of glycemic control is its shorter half-life of 21 days, which renders its serum concentration more sensitive to recent change in average blood glucose level than HbA1C (Guerin-Dubourg et al., 2012).17 Studies have shown decreased albumin levels associated with increased HbA1c and total protein (Shalbha et al., 2015; Malawadi and Adiga, 2016; Nazki et al., 2017).18,19 Therefore, the present study evaluated the glycated haemoglobin, total protein and albumin levels in patients with type 2 diabetes mellitus visiting NAUTH, Nnewi.
Materials and Methods
Study Site
This study was carried out at Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi.
Study design
The present study is a case control study aimed at evaluating the glycated haemoglobin, total protein and albumin levels in patients with type 2 diabetes mellitus visiting NAUTH, Nnewi. The protocol was explained to the subjects and those who gave their informed consent were recruited for the study. A total of 114 subjects comprising of 57 diabetic subjects and 57 controls aged between 40 and 73 years were recruited for the study. The patients and controls were aged and sex matched. Subsequently, structured questionnaire were used to obtain patients’ biodata and thereafter, 5mls of blood sample was collected from each patients and 1ml was dispensed into EDTA for the estimation of glycated haemoglobin, and 4ml was dispensed into plain containers for estimation of serum albumin and total protein levels.
Inclusion and exclusion criteria
Known diabetic subjects aged between 40 and 73 years were recruited for the study, whereas those younger than 40 or older than 73years and non-diabetic subjects were excluded from the study.
Ethical consideration
The ethical clearance for this study was obtained from the Ethics Committee of Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi.
Determination of glycated haemoglobin level
Glycated Haemoglobin level was determined using immunoturbidimetric method as described by Wolf et al., (1984).20
Estimation of serum albumin level
Serum albumin level was estimated Bromo Cresol green Method as described by Doumas et al., (1971).21
Estimation of total protein
Estimation of serum total protein level was done using Biuret Method according to Weichselbaum, (1946).22
Results
The mean level of HbA1c was significantly higher in the diabetic subjects when compared with control group (9.71±1.30Vs 5.58±0.65; p=0.000). There was no significant differences observed between the age, the serum levels of Albumin and Total protein in the test and control subjects (p>0.05).Table 1
Table 1
Table 2 shows that there is no significant correlation between age, HbA1c, total protein and albumin in diabetic subjects.
Discussion
In this study, the mean level of HbA1c was significantly higher in the diabetic subjects than in control. This is in consonance with the report of some previous similar studies (Shalbha et al., 2015; Malawadi and Adiga, 2016; Nazki et al., 2017). This increase can be attributed to hyperglycaemia and disturbances of carbohydrate, fat and protein metabolism that results from abnormalities in insulin secretion, insulin action or even both (IDF, 2015; ADA, 2016).23,5 This finding implies that there is a poor glycemic control in the diabetic subjects under study. Furthermore, our finding shows a higher mean value of HbA1c (9.71±1.30) than the recommended cut-point (<7%) in diabetic patients (ADA, 2010).24 It follows therefore, that these patients may be at greater risk of long-term complications due to diabetes if the glycemic level is not properly controlled and this call for concern in the management of diabetic patients.
However, there was no significant difference between the mean serum level of Albumin in the test subjects when compared with control subjects (p>0.05). This is in line with the report of previous studies (Malawadi and Adiga, 2016). This may be as a result of Insulin resistance which is a principal cause of type 2 diabetes (Kahn, 1994)25 and previously, serum albumin has been associated with insulin resistance (Hostmark et al., 2005; Ishizaka et al., 2007).26,27 In diabetic patients, plasma albumin concentration has been reported to be inversely related with HbA1c levels, revealing a large proportion of poorly controlled diabetes in patients with lower plasma albumin concentrations (Rodriguez-Segade et al., 2005; Hemangi et al., 2012).28,29 This inverse relationship may also be explained by the fact that poorly controlled type 2 diabetes has been associated with a further decrease in insulin production and secretion by the pancreatic β-cell (Marshak et al., 1999; Kahn, 2003).30,31
Furthermore, our finding shows no significant difference between the serum levels of total protein in the diabetic patients and control subjects (p>0.05). This is in contrast with the findings of (Malawadi and Adiga, 2016; Nazki et al., 2017).18,19
There is no significant correlation between age, HbA1c, total protein and albumin in diabetic subjects. This finding is not in agreement with the finding of Hemangi et al., (2012)28 in which plasma albumin levels were negatively correlated with HbA1c and low albumin levels was associated with increased plasma protein glycation and that albumin competes for glycation with other plasma proteins in diabetes.
Conclusion
In conclusion, the present study showed significantly higher mean levels of HbA1c in the diabetic patients compared with the control subjects. However, the mean serum of levels of Albumin and total protein did not differ significantly when compared between the diabetic patients and controls. This finding implies that there was a poor glycemic control in the diabetic subjects studied. Therefore, there is need for better management of diabetic patients through medication and use of diet and exercise.