https://imcjms.com Ibrahim Medical College Journal of Medical Science https://imcjms.com/registration/journal_full_text/94 Sat, 01 Oct 2016 01:16:34 +0000 Abstract Methods: Thirty-two coastal communities in six coastal districts were purposively selected. All coastal people of age 18 years or more were considered eligible. Investigations included clinical history, anthropometry (height, weight, waist- and hip-girth), blood pressure and fasting blood glucose (FBG). The participants with hyperglycemia (FBG ≥5.6mmol/l) were undertaken for eye examination. Visual acuity was measured bilaterally using the Snellen chart. An Early treatment diabetic retinopathy study (ETDRS) cut out chart with E Optotypes was used. Conclusion: The study concludes that visual impairment and cataract of any type is almost comparable with other coastal populations. The coastal people had higher prevalence of DR compared to rural population from other areas of Bangladesh and it was also higher than global estimate. The persons with higher age from higher social class with higher central obesity had excess risk for DR. The risk of DR increased with increasing hyperglycemia. Further study may be undertaken to confirm these findings. IMC J Med Sci 2016; 10(1): 10-17. DOI: https://doi.org/10.3329/imcjms.v10i1.31100 Address for Correspondence: Of the alarming trend of non-communicable diseases (NCD), type 2 diabetes mellitus (T2DM) is common throughout the world and more alarming in the south-east Asian region [1]. A global estimate of diabetes in the year 2000 was 171 million. This figure is likely to be more than double (366 million) by 2030; and most significant increase will occur in the developing countries [1]. T2DM affects elderly people in the developed countries, whereas, in the developing and least developing countries, younger people are more affected [2]. We have the same experience in Bangladesh [3]. Additionally, the prevalence of micro-vascular complications is common in these populations [4-6]. Of the micro-vascular sequels, diabetic retinopathy (DR) was found to be the most disabling complications as it results into loss of vision. A community based study in Sri Lanka reported that more than one-fourth (27.4%) of the diabetic patients had DR [7]. This report indicates that the most diabetic people are prone to develop DR and eventually blindness. For Bangladesh, several population based studies reported the increasing trend of T2DM [8-10]; but there was no community based study on DR. This study addressed the prevalence and risk of DR at the community level in a disaster prone coastal population of Bangladesh.   Material and methods The study protocol was approved by the Ethical Review Committee of the Diabetic Association of Bangladesh (BADAS). Fig.1: Map of Bangladesh showing the location of six coastal districts included in the study [11] Fig.2: Map showing the study sites in each coastal district. Each Dot (n) indicates location of study site [11]   Collection of blood sample: Taking an aseptic measure five ml of fasting blood sample was collected for estimation of fasting blood glucose (FBG mmol/l) and lipids (total cholesterol [T-chol], triglycerides [TG], low-density lipoprotein [LDL] and high-density lipoproteins [HDL]). Finally, biochemical tests were carried out in BIRDEM laboratory. Plasma glucose was measured by glucose oxidase-peroxidase method using Technicon M-II auto-analyzer. To reduce the cost, a randomized sample was drawn (n=225) for the estimation of T-chol, TG and HDL by auto-analyzer (Hitachi-704) using enzymatic method. The coefficient of variation (CV) was allowed ≤5%. While collecting blood sample a drop of blood was taken on a hemo-glucotest strip (One Touch select sample, Lifescan) for rapid assessment of FBG [12]. We used ADA and WHO diagnostic criteria for hyperglycemia and predicting diabetes [13,14]. The participants, who showed FBG ≥5.6 mmol/l, were referred to ophthalmologist for eye examination (Fig 3). The participants presented with eye complaints, irrespective of glycemic status, were also referred.    Figure 3: Algorithm of the study Visual acuity was measured bilaterally using the Snellen chart. An early treatment diabetic retinopathy study (ETDRS) cut out chart with E Optotypes was used [15]. Torch light and pinhole were also used [16]. The cause of visual impairment (cataract, refractive error and retinopathy) was identified [16, 17]. Then the pupil was dilated by using 1% Tropicamide and the fundus was examined with direct ophthalmoscope [18]. Diabetic retinopathy (DR) was diagnosed and classified according to classification of DR and diabetic macular edema [19]. The study findings on DR have been modified for easy presentation: (a) Pre-proliferative – microaneurysms with or without intraretinal hemorrhages; (b) proliferative – neovascularization with or without Vitreous/preretinal hemorrhage; (c) Diabetic macular edema (maculopathy) – any thickening or lipid exudates in the macula [20].   Statistical analyses The prevalence rates of cataract, impaired visual acuity and diabetic retinopathy according to sex, family history and social class were given in percentages with 95% confidence interval (CI). The biophysical characteristics were shown in mean with standard deviation. We used unpaired t-test for comparison of characteristics between participants with and without retinopathy. For assessment of risk odds ratio (OR) with 95% CI were used. SPSS version 20 was used for all analyzing qualitative and quantitative data. Less than 0.05 was considered significant.   Results The prevalence of DR according to sex, social class and family history were shown in table 2. The prevalence of DR was significantly higher among those who had known diabetic member in their first degree relatives than those who had no known diabetic member in their families. Regarding social class, the affluent participants had significantly higher DR than their non-affluent counterparts. Compared with the women the men had higher frequency though not significant.   Table-2: Prevalence [% (95% CI*)] of retinopathy according to sex, family history (n=1412) and social class (n=1377)   Table 3 showed the comparisons of biophysical characteristics between participants with and without DR. The participants with DR had significantly higher age (p<0.001), higher central obesity (WHR p<0.001; and WHtR p=0.01), higher fasting FBG (p<0.001). Interestingly, there was no significant difference in general obesity (BMI p=0.917). Even more interesting is that the participants with DR had significantly lower total cholesterol (p=0.03) and lower low-density lipoprotein (LDL p=0.047).   Table-3: Comparison of characteristics between participants with and without retinopathy     No retinopathy n=617 Retinopathy n=145   Characteristics Mean SD† Mean SD p‡ Age (y) 47.7 13.4 52.4 12.8 0.001 BMI 23.6 3.9 23.6 3.5 .917 WHR 0.896 0.081 0.925 0.072 0.001 WHTR 0.507 0.072 0.523 0.061 .010 SBP (mmHg) 127.4 21.9 129.8 24.2 .238 DBP (mmHg) 81.8 12.6 81.9 11.1 .921 FBG (mmol/l) 6.8 3.1 8.9 4.5 0.001 Chol (mg/dl)* 221 69 189 48 .030 TG (mg/dl)* 176 122 150 82 .323  HDL (mg/dl)* 46.2 10.4 44.5 11.4 .468 LDL (mg/dl)* 139.9 59.6 114.6 41.5 .047 † SD – standard deviation; ‡ p after unpaired t-test; * - a randomized sample size (n = 225)   This is the first study, which addressed the prevalence of DR and visual impairment in a coastal population. Some socio-demographic and biophysical risk factors were also assessed. Two important aspects of the study are worth mentioning. Firstly, the study population has least access to health care services and diagnostic facilities. Secondly, the study areas are mostly inaccessible due to inconvenient communication and precarious weather condition. We had some advantages. We could refer the persons with cataract to nearby centers for surgery organized and maintained by Fred Hollow Foundation. The local people especially teachers and students were very much cordial. They actively and sincerely volunteered the study in every step (carrying message to the villagers from house to house and making list of the participants and taking them to the investigation site. So far available a population based study of Bangladesh showed that overall prevalence of DR was 5.4% among the rural people of age 30 years or older [22]. Our study demonstrated that compared with the rural people of other areas of Bangladesh, the coastal people had increased prevalence of DR. An estimated global prevalence of ‘any DR’ was found 6.96% (95CI, 6.87-7.04) [23]. Thus, the global estimate also indicates that the coastal people are more susceptible for developing DR. A ‘Singapore Eye Study’ among the migrant Indians (age >40y) reported that the prevalence of DR was 10.5% (95% CI, 9.3-11.8) [24]. This finding also showed that our study population bears greater risk for DR. An interesting finding was that the level of total cholesterol and LDL-cholesterol was found significantly lower in those who had no DR than those who had. The findings indicate that these lipid fractions appear to be protective against DR. The explanation is not known. We conclude that the prevalence of visual impairment and cataract is comparable with other studies; whereas, the prevalence of DR among the coastal people was higher than that of the rural Bangladeshis and also higher than global estimates and Indian migrants. The persons with higher age from higher social class with higher central obesity had excess risk for both diabetes and DR. Further study may be undertaken to confirm the study findings and if found consistent then the coastal people need an urgent Eye Care facilities for the prevention of visual impairment and blindness. Acknowledgements – We are grateful to Fred Hollow Foundation (FHF) for their financial support. We are indebted to Prof AH Syedur Rahman, Department of Ophthalmology, BIRDEM for his initiative to communicate to FHF. We deeply acknowledge him posthumously with all our deepest respect. We appreciate the cooperation extended by the Ibrahim Medical College and the Department of Ophthalmology, BSMMU, Dhaka. We are grateful and obliged to the teachers, students and all participants of coastal area for their cordial and pleasant hospitality.   References 2. World Health Organization: Guidelines for the prevention, management and care of diabetes mellitus. EMRO Technical publications series 32, Geneva 2006. 4. Sayeed MA, Khanam PA, Choudhury RI, Mahtab H, Azad Khan AK. Retinopathy and nephropathy are the most prevalent complications among diabetic subjects in Bangladesh. Diabetologia 2005; 48(Suppl 1): Abs-944 (P: A343). 6. Sayeed MA, Khanam PA, Mahtab H and Azad Khan AK. Microvascular complications among diabetic subjects predominate in the long-term follow up: 15-year retrospective study. Diab Res Clin Pract 2000; 50: S116. 7. Katulanda P, Priyanga Ranasinghe P and  Jayawardena R. Prevalence of retinopathy among adults with self-reported diabetes mellitus: the Sri Lanka diabetes and Cardiovascular Study. BMC Ophthalmol 2014; 14: 100. doi: 10.1186/1471-2415-14-100 8. Sayeed MA, Mahtab H, Khanam PA, Latif ZA, Banu A and Azad Khan AK. Prevalence of diabetes and impaired fasting glucose in urban population of Bangladesh. Bangladesh Med Res Counc Bull 2007; 33(1): 1-12. 10. Rahim MA, Hussain A, Azad Khan AK, Sayeed MA, Keramat Ali SM, Vaaler S. Rising prevalence of type 2 diabetes in rural Bangladesh: a population based study.Diabetes Res Clin Pract 2007; 77(2): 300-305. 12. Florkowski C, Budgen C, Kendall D, Lunt H and Moore MP. Comparison of blood glucose meters in a New Zealand diabetes centre. Ann Clin Biochem 2009; 46: 302–305. 14. American Diabetes Association. Standards of Medical Care in Diabetes—2011. Diabetes Care 2011; 34(Suppl 1): S11–S61. 16. Neena J, Rachel J, Praveen V, Murthy GV. Rapid assessment of avoidable blindness in India.PLOS One 2008; 3: e2867. 18. Klein R, Klein BEK, Moss SE, Davis MD, Demets DL. The Wisconsin epidemiologic study of diabetic retinopathy-X. Four year incidence and progression of diabetic retinopathy, when age at diagnosis is 30 years or more. Arch Ophthalmol 1989; 107: 244–49. 2026 Ibrahim Medical College. All rights reserved.