The need for obtaining accurate nationwide estimates of diabetes prevalence in India - Rationale for a national study on diabetes.

According to the World Diabetes Atlas, India is projected to have around 51 million people with diabetes. However, these data are based on small sporadic studies done in some parts of the country. Even a few multi-centre studies that have been done, have several limitations. Also, marked heterogeneity between States limits the generalizability of results. Other studies done at various time periods also lack uniform methodology, do not take into consideration ethnic differences and have inadequate coverage. Thus, till date there has been no national study on the prevalence of diabetes which are truly representative of India as a whole. Moreover, the data on diabetes complications is even more scarce. Therefore, there is an urgent need for a large well-planned national study, which could provide reliable nationwide data, not only on prevalence of diabetes, but also on pre-diabetes, and the complications of diabetes in India. A study of this nature will have enormous public health impact and help policy makers to take action against diabetes in India.

Increased awareness about diabetes and its complications in a whole city: effectiveness of the "prevention, awareness, counselling and evaluation" [PACE] Diabetes Project [PACE-6].

AIMS AND OBJECTIVES: To determine the effectiveness of a large scale multipronged diabetes awareness program provided through community involvement in Chennai. MATERIAL AND METHODS: Mass awareness and free screening camps were conducted between 2004-2007 at various locations of Chennai as part of the Prevention, Awareness, Counselling and Evaluation [PACE] Diabetes Project. During a 3-year period, 774 diabetes awareness camps were conducted to reach the public directly. After the PACE project was completed, 3000 individuals, representative of Chennai, were surveyed in 2007 using a systematic stratified random sampling technique. The results were compared to a similar survey carried out, as part of the Chennai Urban Rural Epidemiology Study [CURES] in 2001-2002, which served as a measure of baseline diabetes awareness. RESULTS: Awareness of a condition called "diabetes" increased significantly from 75.5% in 2001-2002 (CURES) to 81% (p < 0.001) in 2007 (PACE). 74.1% of the citizens of Chennai are now aware that the prevalence of diabetes is increasing as compared to 60.2% earlier [p < 0.001]. Significantly more people felt that diabetes could be prevented (p < 0.001), and that a combination of diet and exercise were needed to do so (p < 0.001). Respondents reporting obesity, family history of diabetes, hypertension and mental stress as risk factors increased significantly after PACE (p < 0.001). More people were able to correctly identify the eyes (PACE 38.1% compared to CURES--16.1%, p < 0.001), kidney (PACE 42.3% compared to CURES 16.10%, p < 0.001), heart (PACE 4.6% compared to CURES 5.8%, p < 0.001) and feet (PACE 35.0% vs. CURES 21.9%, p < 0.001) as the main organs affected by diabetes. CONCLUSION: Through direct public education and mass media campaigns, awareness about diabetes and its complications can be improved even in a whole city. If similar efforts are implemented state-wise and nationally, prevention and control of non-communicable diseases, specifically diabetes and cardiovascular disease, is an achievable goal in India.

Prevention awareness counselling and evaluation (PACE) diabetes project: a mega multi-pronged program for diabetes awareness and prevention in South India (PACE- 5).

OBJECTIVE: The Prevention Awareness Counselling Evaluation (PACE) Diabetes Project is a large scale community based project carried out to increase awareness of diabetes and its complications in Chennai city (population: 4.7 million) through 1) public education 2) media campaigns 3) general practitioner training 4) blood sugar screening and 5) community based "real life" prevention program METHODS: Education took place in multiple forms and venues over the three-year period of the PACE project between 2004-2007. With the help of the community, awareness programs were conducted at residential sites, worksites, places of worship, public places and educational institutions through lectures, skits and street plays. Messages were also conveyed through popular local television and radio channels and print media. The General Practitioners (GPs) program included training in diabetes prevention, treatment and the advantages of early detection of complications. Free random capillary blood glucose testing was done for individuals who attended the awareness programs using glucose meter. RESULTS: Over a three-year period, we conducted 774 education sessions, 675 of which were coupled with opportunistic blood glucose screening. A total of 76,645 individuals underwent blood glucose screening. We also set up 176 "PACE Diabetes Education Counters" across Chennai, which were regularly replenished with educational materials. In addition, we trained 232 general practitioners in diabetology prevention, treatment and screening for complications. Multiple television and radio shows were given and messages about diabetes sent as Short Message Service (SMS) through mobile phones. Overall, we estimate that we reached diabetes prevention messages to nearly two million people in Chennai through the PACE Diabetes Project, making it one of the largest diabetes awareness and prevention programs ever conducted in India. CONCLUSION: Mass awareness and screening programs are feasible and, through community empowerment, can help in prevention and control of non-commuincable diseases such as diabetes and its complications on a large scale.

Diabetic retinopathy: an Indian perspective.

Diabetic retinopathy (DR) can be defined as damage to microvascular system in the retina due to prolonged hyperglycaemia. The prevalence of DR in the Chennai Urban Rural Epidemiology (CURES) Eye Study in south India was 17.6 per cent, significantly lower than age-matched western counterparts. However, due to the large number of diabetic subjects, DR is likely to pose a public health burden in India. CURES Eye study showed that the major systemic risk factors for onset and progression of DR are duration of diabetes, degree of glycaemic control and hyperlipidaemia. Hypertension did not play a major role in this cross-sectional analysis. The role of oxidative stress, atherosclerotic end points and genetic factors in susceptibility to DR has been studied. It was found that DR was associated with increased intima-media thickness and arterial stiffness in type 2 Indian diabetic subjects suggesting that common pathogenic mechanisms might predispose to diabetic microangiopathy. Curcumin, an active ingredient of turmeric, has been shown to inhibit proliferation of retinal endothelial cells in vivo. Visual disability from DR is largely preventable if managed with timely intervention by laser. It has been clearly demonstrated that in type 2 south Indian diabetic patients with proliferative DR who underwent Pan retinal photocoagulation, 73 per cent eyes with good visual acuity (6/9) at baseline maintained the same vision at 1 yr follow up. There is evidence that DR begins to develop years before the clinical diagnosis of type 2 diabetes. Our earlier study demonstrated that DR is present in 7 per cent of newly diagnosed subjects, hence routine retinal screening for DR even at the time of diagnosis of type 2 diabetes may help in optimized laser therapy. Annual retinal examination and early detection of DR can considerably reduce the risk of visual loss in diabetic individuals.

Does hypertension play a role in diabetic retinopathy?

Diabetic retinopathy is a common complication of diabetes. It represents one of the frequent causes of visual disability among diabetic subjects during the period of active life. The risk factors for diabetic retinopathy are poor glycemic control, hypertension, duration of diabetes, hyperlipidemia and proteinuria. It has been observed that prevalence of hypertension is higher in diabetic subjects than in the general population and as it also plays a major role in the progression of diabetic retinopathy, so tight control of hypertension is mandatory. The possible mechanisms by which hypertension affects diabetic retinopathy are haemodynamic (impaired autoregulation and hyperperfusion) and secondly through VEGF (Vascular Endothelial Growth Factor), as it has been observed that hypertension independent of hyperglycaemia upregulates the VEGF expression in retinal endothelial cells and ocular fluids. The level of control of blood pressure are debatable but nearer the blood pressure to the normal levels, better the chances of preventing the onset and progression of diabetic retinopathy. The lowering of blood pressure to a normal range is more important than the type of antihypertensive medication used. Diabetic retinopathy is one of the important causes of visual disability in diabetic subjects during the period of active life. It is characterized by gradually progressive alterations in the retinal microvasculature, leading to increased vasopermeability, areas of retinal occlusion and retinal neovascularization. The complications associated with increased vasopermeability and uncontrolled neovascularization can result in severe and permanent visual loss.

The Chennai Urban Rural Epidemiology Study (CURES)--study design and methodology (urban component) (CURES-I).

The report of World Health Organization (WHO) shows that India tops the world with the largest number of diabetic subjects. This increase is attributed to the rapid epidemiological transition accompanied by urbanization, which is occurring in India. There is very little data regarding the influence of affluence on the prevalence of diabetes and its complications particularly retinopathy in the Indian population. Furthermore, there are very few studies comparing the urban/rural prevalence of diabetes and its complications. The Chennai Urban Rural Epidemiology Study (CURES) is designed to answer the above questions. CURES is initially planned as a cross-sectional study to evolve later into a longitudinal study. Subjects for the urban component of the CURES have been recruited from within the corporation limits of Chennai City. Chennai (formerly Madras), the largest city in Southern India and the fourth largest in India has been divided into 10 zones and 155 wards. 46 wards were selected by a systematic random sampling method to represent the whole of Chennai. Twenty thousand and one individuals were recruited for the study, this number being derived based on a sample size calculation. The study has three phases. Phase one is a door to door survey which includes a questionnaire, anthropometric, fasting capillary blood glucose and blood pressure measurements. Phase two focussed on the prevalence of diabetic complications particularly retinopathy using standardized techniques like retinal photography etc. Diabetic subjects identified in phase one and age and sex matched non-diabetic subjects will participate in these studies. Phase three will include more detailed studies like clinical, biochemical and vascular studies on a sub-sample of the study subjects selected on a stratified basis from phase one. CURES is perhaps one of the largest systematic population based studies to be done in India in the field of diabetes and its complications like retinopathy, nephropathy and neuropathy.

Prevalence of non-diabetic renal disease in type 2 diabetic patients in a diabetes centre in Southern India.

OBJECTIVE: The Aim of Study is to determine the prevalence of non-diabetic renal disease among South Indian type 2 diabetic subjects based on renal biopsy. METHODS: Three thousand five hundred and ninety subjects with complete records were included for the study. One hundred and forty subjects who had proteinuria but no evidence of retinopathy undertook a 24 hour proteinuric estimation. Of these 140 subjects, 28 subjects had proteinuria > 1,000 mg/day and were subjected to renal imaging. Seven subjects were excluded due to renal calculi, cysts or contracted kidneys. Of the remaining 21 diabetic subjects, one subject was excluded as he had a mild diabetic retinopathy on fundus fluorescein angiography. Of the 20 subjects included 18 participated in the renal biopsy study (response rate--90%). Renal pathology of these subjects were studied. RESULTS: Of the 18 renal biopsies, two were excluded due to different reasons. Out of 16 patients, eight (50%) had pathological changes suggestive of diabetic etiology, five (33.3%) had classical membranous nephropathy, one (6.2%) had tubulo-interstitial disease and two (12.5%) were categorized as others with minimal changes. The subjects with non-diabetic renal disease had significantly higher creatinine clearance (p = 0.024), serum cholesterol (p = 0.036), triglyceride levels (p = 0.045) and LDL cholesterol (p = 0.048) compared to subjects with diabetic nephropathy. CONCLUSION: This study suggests that even in subjects clinically suspected to have non-diabetic renal disease many may turn out to have diabetic nephropathy on renal biopsy.

Lipoprotein(a) in South Indian type 2 diabetic subjects in relation to diabetic vascular complications.

OBJECTIVES: Lipoprotein(a) [LP(a)] has been reported to be an independent risk factor for coronary artery disease (CAD). However, its relationship with other vascular complications is not clear. The aim of the study was to determine the relation of lipoprotein(a) with micro- and macrovascular complications seen in type 2 diabetic patients. METHODS: We studied 725 type 2 diabetic patients with and without diabetic complications at the MV Diabetes Specialities Centre, Chennai. The mean age of the study group was 54 +/- 10 years and 70% were males. Diabetic complications viz retinopathy, proteinuria, peripheral vascular disease and coronary artery disease were diagnosed using standardized definitions. Lipoprotein(a) levels were measured using enzyme linked immunosorbant assay (ELISA). Since the frequency distribution of Lp(a) was skewed Lp(a) values were log transformed and geometric mean was used for statistical analysis. RESULTS: The mean Lp(a) level of patients with any vascular complication was significantly higher compared to the subjects without any complications. Multiple logistic regression analysis revealed that lipoprotein(a) had as independent association with CAD (Odds Ratio -1.16, p=0.04) and proteinuria (Odds Ratio -1.69, p < 0.001). The association of Lp(a) with retinopathy and PVD turned out to be non-significant when CAD and proteinuria was introduced as cofactors in the regression model. CONCLUSION: Lp(a) concentrations are found to be higher in those with CAD and proteinuria. There appears to be no association between Lp(a) and retinopathy or PVD in South Indian type 2 diabetic patients.

Acute phase serum proteins in diabetic retinopathy.

The serum concentration of various acute phase reactants were studied in patients with non-insulin dependent mellitus with and without retinopathy and in control subjects. The serum levels of haptoglobin was elevated in diabetics with retinopathy and the levels were highest in those with proliferative diabetic retinopathy. The levels of serum albumin, alpha-1 acid glycoprotein, alpha-1 antitrypsin and caeruloplasmin were not significantly different between the patients with retinopathy and controls. Haptoglobin increases serum viscosity and this could be the mechanism by which it plays a role in pathogenesis of diabetic retinopathy. These preliminary observations need to be confirmed by studies based on larger number of patients. Longitudinal studies on acute phase reactants in various stages of development of diabetic retinopathy would also provide valuable information.

Does oxidant stress play a role in diabetic retinopathy?

The role of oxidant stress in the causation of chronic tissue damage is being increasingly recognized. Oxidant stress is usually countered by abundant supply of antioxidants. If concomitant antioxidant deficiency occurs, oxidant stress may produce tissue damage. We took up a study on antioxidant status in non-insulin dependent diabetes mellitus (NIDDM) patients with and without retinopathy and compared them with a control non-diabetic group. The levels of superoxide dismutase (SOD) were significantly reduced in all diabetic patients, i.e., those with and without retinopathy. However, the lowest levels were found in the diabetic patients with retinopathy. Vitamin E and vitamin C levels were also markedly lower in the diabetic patients. There was a paradoxical rise in the catalase and glutathione peroxidase (GPx) in the diabetic patients with retinopathy. This may be a compensatory mechanism by the body to prevent tissue damage by increasing the levels of the two alternative antioxidant enzymes.