Impact of type 2 Diabetes Mellitus for developing severe health complications in Bangladeshi population

Type 2 diabetes mellitus is one of the deadliest disease in Bangladesh as its complications are enormous and life threatening. This study demonstrates the prevalence of the complications of type 2 diabetes among the population of Bangladesh. Data of 1000 subjects admitted into BIRDEM General Hospital from May 2015 to April 2016 were taken into consideration. Significantly, it was found that 89% patients had fasting blood glucose (FBG) level greater than 7 mmol/l and 70.8% patients had glycosylated hemoglobin (HbA1c) level greater than 8%. As a consequence, the total population were affected by diverse health complications including lung, liver, cardiovascular, kidney, brain, oral, eye, thyroid, hearing, skin, and so on. Males and females were suffered from these complications without biasedness.


Introduction
Global prevalence of diabetes is increasing day by day.It was estimated that the prevalence of diabetes in 2000 was 2.8% and will be 4.4% in 2030 indicating that 366 million people will be affected by this disease in 2030 (Wild et al., 2004).Type 2 diabetes mellitus (T2DM) is most common among the other types and the highest increase of its occurrence is, however, predicted to appear in Asia (Wild et al., 2004).T2DM which was formally denoted as "adult onset diabetes" or "non-insulin dependent diabetes mellitus" (NIDDM), is the consequence of body's inability of using insulin.Long-term complications from this disease include lung, liver, cardiovascular, kidney, brain, oral, eye, foot, skin diseases, and hearing impairments which possess deleterious effect on the body.Lung diseases in diabetic patients include asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, pneumonia, and tuberculosis (Ehrlich et al., 2010).The entire degree of liver complications is detected in diabetic patients.Liver condition deteriorates in aberrant homeostasis of blood glucose which eventually plays significant roles in developing cholelithiasis, hepatitis B and C, cirrhosis and non-alcoholic fatty liver disease (NAFLD)in diabetic patients (Tolman et al., 2007).Diabetes causes damage to the blood vessels and blocks the natural circulation of blood which affects heart normally known as cardiovascular disease (CVD).CVD including heart failure, cardiomyopathy, peripheral arterial disease (PAD), and coronary heart disease frequently observed in diabetic patients (Wilson, 1998).Nephropathy, microalbuminuria, proteinuria, kidney failure being the major types of kidney diseases are quite familiar in diabetic patients (Coresh et al., 2003).These diseases take several years to develop.Diabetic patients have the increased risks of developing brain diseases like stroke, and dementia (Beul, 1994;Ott et al., 1996).Another less frequent brain disease named Alzheimer's disease (AD) is closely related to diabetes (Li et al., 2015).Diabetic patients suffer from some common oral diseases like periodontitis, oral mucosal lesion (OML), and dental caries (Al-Maskari et al., 2011).Eye diseases including retinopathy, diabetic macular edema, cataract, and glaucoma are prevalent among diabetic patients and these diseases often lead to blindness (Moss et al., 1998).Though T2DM is found responsible for a number of long-term health complications among the adult population, it is little known about their occurrence in Bangladeshi population.In this study, the current status of T2DM patients is detected and the prevalence of lung, liver, heart, kidney, brain, oral, eye, thyroid, hearing, skin and foot complications related to T2DM are measured.The role of gender in the manifestation of these complications is also investigated.

Design
The study was conducted among 1000 patients (500 males and 500 females) aged between 31-90 years who were attending the BIRDEM General Hospital under Bangladesh Institute of Research & Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) from May 2015 to April 2016.BIRDEM is the leading diagnosis and treatment hospital of Bangladesh for diabetes.As a result the collected data are significant as enormous patients attend this medical organization for treatment of diabetes.All information including tests was used here considering the oral and written informed consent of the patients.In addition, the ethical issues of the hospital also maintained here.Disease profile and personal information of the patients related to the study were taken into consideration and written down in the questionnaire.

Measurement of parameters
Blood samples were collected from the patients for measuring fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c).FBG level was assessed using glucose oxidase and peroxidase method while HbA1c was evaluated by immunoturbidimetric inhibition method (Zander et al., 1984;Marks, 1996).

Statistical analysis
For statistical analysis, SPSS (SPSS Inc., Chicago, USA) and MS Excel 2016 Analysis ToolPak were used.Prevalence with confidence interval (CI) was measured where significance level was set at 95%.Exact binomial value was used as the value of CI.Sample proportion of male and female was compared using z-test.For each characteristic of complications, p-value and male to female ratio were calculated.The significance of the result was considered as p<0.05.

Discussion
T2DM simultaneously influences in developing a number of metabolic disorders which eventually result in various death threatening complications.It is often observed that many patients develop more than one complication at a time.Very limited studies have been carried out about the complications related to T2DM in Bangladesh.In fact, this is the first study elucidating the overall scenarios of these complications among the diabetic patients in this particular area.Approximately 11.4%, 24.6%, 14.5%, 11.7%, 8.6%, 8%, 6.4%, 3%, 10.4%, 7.5%, and 9.3% of the total population were affected by lung, liver, cardiovascular, kidney, brain, oral, eye, thyroid, hearing, skin, and foot diseases respectively.In this study, among the 11.4% of lung disease patients, asthma, COPD, pulmonary fibrosis, pneumonia, tuberculosis, and lung cancer prevalence are 2.9%, 3.5%, 1.7%, 1.1%, 1.9%, and 0.3% respectively.Female patients are affected more by asthma, COPD, and pneumonia.Liver diseases have the prevalence of 24.6% which consists of cholelithiasis (7.5%), hepatitis B (0.8%), hepatitis C(1.7%), cirrhosis (1.5%), and NAFLD (14.4%).Liver diseases are highly prevalent than the other type of diseases and male patients have the slightly higher risk of developing hepatitis B, liver cirrhosis, and NAFLD.Hepatitis C is significantly more prevalent among female patients (p<0.05).The prevalence of cardiovascular diseases is 14.5% which contains heart failure (7.9%), cardiomyopathy (0.9%), peripheral arterial disease (3.8%), and coronary heart disease (2.3%).Male and female patients are quite equally affected by these diseases but the risk of having heart failure is found higher in male patients.Kidney diseases which consist of nephropathy (5.1%), microalbuminuria (2.4%), proteinuria (1.3%), and chronic kidney disease (2.9%) have the prevalence of 11.7%.In this case, female patients have the higher risk of developing these complications.A previous study showed that chronic kidney disease was highly prevalent in T2DMpatients in the urban areas of Bangladesh (Anand et al., 2014).The prevalence of brain disease is 8.6% where stroke, dementia, and Alzheimer's disease have the prevalence of 6.9%, 1.5%, and 0.3% respectively.Male patients develop these diseases more than the female patients.Oral diseases have the prevalence of 8% where periodontitis, oral mucosal lesion, and dental caries have the prevalence of 3.1%, 2.9% and 2.2% respectively.Periodontitis has the higher prevalence in female patients while oral mucosal lesion is found high in male patients.A previous study showed that the dental diseases were significantly prevalent among the T2DM patients of this area (Choudhury et al., 2016).Eye diseases have the prevalence of 6.4 % where retinopathy, diabetic macular edema, cataract, and glaucoma have the prevalence of 2.5%, 1.1%, 1.7%, and 1.1% respectively.Retinopathy and diabetic macular edema have the higher prevalence in female patients.
Cataract is significantly higher in male patients (p<0.05).The prevalence of diabetic retinopathy was found high (4.1%) in a previous study (Ahmed et al., 2012).The prevalence of thyroid disorder is 3% which is composed of hypothyroidism (2.1%) and hyperthyroidism (0.9%).The occurrence of these diseases are also almost equal among male and female patients.In a previous study, the prevalence of thyroid dysfunction among T2DM patients was found 10% in an urban diabetic hospital of Bangladesh (Moslem et al., 2015).The prevalence of hearing impairment, skin diseases, and diabetic foot diseases are 10.4%, 7.5% and 9.3% respectively.The prevalence of hearing impairment is significantly higher in female patients while skin diseases and diabetic foot diseases are significantly higher in male patients (p<0.05).The complications of T2DM develop gradually and to control these complications, blood sugar and HbA1c should be monitored frequently.T2DM can be managed by following healthy lifestyle such as eating foods which are higher in fiber and lower in calories, taking regular physical activity and carefully monitoring the blood glucose level.Some frequently reported risk factors of T2DM include geography, ethnicity, gender, family history of having this disease, prediabetes, gestational diabetes, overweight, physical inactivity, age, poor eating habits etc.These should be checked.Though the study was performed with great care, there were some limitations which could not easily be avoided.Some patients were under medications and the effects of such medications in altering the level of FBG and HbA1c were not clearly known.

Conclusions
The current study signifies some sound and profound findings.Firstly, the current status of T2DM and its complications among the population of Bangladesh are depicted.Utmost seriousness is given to get the whole scenarios of these complications.Secondly, the role of gender in developing these complications is detected and in some cases, it is observed that gender plays a significant role.This study may facilitate in acquiring the overview of T2DM disease, its complications and provide support in developing improved strategies to manage, control and prevent these complications.

Table 1 . Status of FBG and HbA1c and prevalence of the major complications among type 2 diabetic patients.
a=95 % confidence interval; b=male: female; *=significant at 95 % confidence interval