Ranjit Unnikrishnan

PREVALENCE AND RISK FACTORS OF DIABETIC NEPHROPATHY IN AN URBAN SOUTH INDIAN POPULATION: THE CHENNAI URBAN RURAL EPIDEMIOLOGY STUDY (CURES - 45)

OBJECTIVE—The aim of this study was to determine the prevalence of diabetic nephropathy among urban Asian-Indian type 2 diabetic subjects. RESEARCH DESIGN AND METHODS—Type 2 diabetic subjects (n = 1,716), inclusive of known diabetic subjects (KD subjects) (1,363 of 1,529; response rate 89.1%) and randomly selected newly diagnosed diabetic subjects (NDD subjects) (n = 353) were selected from the Chennai Urban Rural Epidemiology Study (CURES). Microalbuminuria was estimated by immunoturbidometric assay and diagnosed if albumin excretion was between 30 and 299 μg/mg of creatinine, and overt nephropathy was diagnosed if albumin excretion was ≥300 μg/mg of creatinine in the presence of diabetic retinopathy, which was assessed by stereoscopic retinal color photography. RESULTS—The prevalence of overt nephropathy was 2.2% (95% CI 1.51–2.91). Microalbuminuria was present in 26.9% (24.8–28.9). Compared with the NDD subjects, KD subjects had greater prevalence rates of both microalbuminuria with retinopathy and overt nephropathy (8.4 vs. 1.4%, P < 0.001; and 2.6 vs. 0.8%, P = 0.043, respectively). Logistic regression analysis showed that A1C (odds ratio 1.325 [95% CI 1.256–1.399], P < 0.001), smoking (odds ratio 1.464, P = 0.011), duration of diabetes (1.023, P = 0.046), systolic blood pressure (1.020, P < 0.001), and diastolic blood pressure (1.016, P = 0.022) were associated with microalbuminuria. A1C (1.483, P < 0.0001), duration of diabetes (1.073, P = 0.003), and systolic blood pressure (1.031, P = 0.004) were associated with overt nephropathy. CONCLUSIONS—The results of the study suggest that in urban Asian Indians, the prevalence of overt nephropathy and microalbuminuria was 2.2 and 26.9%, respectively. Duration of diabetes, A1C, and systolic blood pressure were the common risk factors for overt nephropathy and microalbuminuria.

Prevalence of dyslipidemia in urban and rural India: the ICMR-INDIAB study.

Aim To study the pattern and prevalence of dyslipidemia in a large representative sample of four selected regions in India. Methods Phase I of the Indian Council of Medical Research–India Diabetes (ICMR-INDIAB) study was conducted in a representative population of three states of India [Tamil Nadu, Maharashtra and Jharkhand] and one Union Territory [Chandigarh], and covered a population of 213 million people using stratified multistage sampling design to recruit individuals ≥20 years of age. All the study subjects (n = 16,607) underwent anthropometric measurements and oral glucose tolerance tests were done using capillary blood (except in self-reported diabetes). In addition, in every 5th subject (n = 2042), a fasting venous sample was collected and assayed for lipids. Dyslipidemia was diagnosed using National Cholesterol Education Programme (NCEP) guidelines. Results Of the subjects studied, 13.9% had hypercholesterolemia, 29.5% had hypertriglyceridemia, 72.3% had low HDL-C, 11.8% had high LDL-C levels and 79% had abnormalities in one of the lipid parameters. Regional disparity exists with the highest rates of hypercholesterolemia observed in Tamilnadu (18.3%), highest rates of hypertriglyceridemia in Chandigarh (38.6%), highest rates of low HDL-C in Jharkhand (76.8%) and highest rates of high LDL-C in Tamilnadu (15.8%). Except for low HDL-C and in the state of Maharashtra, in all other states, urban residents had the highest prevalence of lipid abnormalities compared to rural residents. Low HDL-C was the most common lipid abnormality (72.3%) in all the four regions studied; in 44.9% of subjects, it was present as an isolated abnormality. Common significant risk factors for dyslipidemia included obesity, diabetes, and dysglycemia. Conclusion The prevalence of dyslipidemia is very high in India, which calls for urgent lifestyle intervention strategies to prevent and manage this important cardiovascular risk factor.

Incidence of Diabetes and Prediabetes and Predictors of Progression Among Asian Indians: 10-Year Follow-up of the Chennai Urban Rural Epidemiology Study (CURES)

OBJECTIVE There are few data on the incidence rates of diabetes and prediabetes (dysglycemia) in Asian Indians. This article presents the incidence of diabetes and prediabetes and the predictors of progression in a population-based Asian Indian cohort. RESEARCH DESIGN AND METHODS Data on progression to diabetes and prediabetes from 1,376 individuals, a subset of 2,207 of the Chennai Urban Rural Epidemiology Study (CURES) cohort (phase 3) with normal glucose tolerance (NGT) or prediabetes at baseline, who were followed for a median of 9.1 years (11,629 person-years), are presented. During follow-up, 534 died and 1,077 with NGT and 299 with prediabetes at baseline were reinvestigated in a 10-year follow-up study. Diabetes and prediabetes were diagnosed based on the American Diabetes Association criteria. Incidence rates were calculated and predictors of progression to prediabetes and/or diabetes were estimated using the Cox proportional hazards model. RESULTS The incidence rates of diabetes, prediabetes, and “any dysglycemia” were 22.2, 29.5, and 51.7 per 1,000 person-years, respectively. Among those with NGT, 19.4% converted to diabetes and 25.7% to prediabetes, giving an overall conversion rate to dysglycemia of 45.1%. Among those with prediabetes, 58.9% converted to diabetes. Predictors of progression to dysglycemia were advancing age, family history of diabetes, 2-h plasma glucose, glycated hemoglobin (HbA1c), low HDL cholesterol, and physical inactivity. CONCLUSIONS Asian Indians have one of the highest incidence rates of diabetes, with rapid conversion from normoglycemia to dysglycemia. Public health interventions should target modifiable risk factors to slow down the diabetes epidemic in this population.

Diabetes mellitus and its complications in India

India is one of the epicentres of the global diabetes mellitus pandemic. Rapid socioeconomic development and demographic changes, along with increased susceptibility for Indian individuals, have led to the explosive increase in the prevalence of diabetes mellitus in India over the past four decades. Type 2 diabetes mellitus in Asian Indian people is characterized by a young age of onset and occurrence at low levels of BMI. Available data also suggest that the susceptibility of Asian Indian people to the complications of diabetes mellitus differs from that of white populations. Management of this disease in India faces multiple challenges, such as low levels of awareness, paucity of trained medical and paramedical staff and unaffordability of medications and services. Novel interventions using readily available resources and technology promise to revolutionise the care of patients with diabetes mellitus in India. As many of these challenges are common to most developing countries of the world, the lessons learnt from Indias experience with diabetes mellitus are likely to be of immense global relevance. In this Review, we discuss the epidemiology of diabetes mellitus and its complications in India and outline the advances made in the country to ensure adequate care. We make specific references to novel, cost-effective interventions, which might be of relevance to other low-income and middle-income countries of the world.

Prevalence of generalized & abdominal obesity in urban & rural India- the ICMR - INDIAB Study (Phase-I) [ICMR - INDIAB-3]

Background & objectives: Overweight and obesity are rapidly increasing in countries like India. This study was aimed at determining the prevalence of generalized, abdominal and combined obesity in urban and rural India. Methods: Phase I of the ICMR-INDIAB study was conducted in a representative population of three States [Tamil Nadu (TN), Maharashtra (MH) and Jharkhand (JH)] and one Union Territory (UT)[Chandigarh (CH)] of India. A stratified multi-stage sampling design was adopted and individuals ≥20 yr of age were included. WHO Asia Pacific guidelines were used to define overweight [body mass index (BMI) ≥23 kg/m2 but <25 kg/m2), generalized obesity (GO, BMI≥25kg/m2), abdominal obesity (AO, waist circumference ≥90 cm for men and ≥80cm for women) and combined obesity (CO, GO plus AO). Of the 14,277 participants, 13,800 subjects (response rate, 96.7%) were included for the analysis (urban: n=4,063; rural: n=9737). Results: The prevalence of GO was 24.6, 16.6, 11.8 and 31.3 per cent among residents of TN, MH, JH and CH, while the prevalence of AO was 26.6, 18.7, 16.9 and 36.1 per cent, respectively. CO was present in 19.3, 13.0, 9.8 and 26.6 per cent of the TN, MH, JH and CH population. The prevalence of GO, AO and CO were significantly higher among urban residents compared to rural residents in all the four regions studied. The prevalence of overweight was 15.2, 11.3, 7.8 and 15.9 per cent among residents of TN, MH, JH and CH, respectively. Multiple logistic regression analysis showed that female gender, hypertension, diabetes, higher socio-economic status, physical inactivity and urban residence were significantly associated with GO, AO and CO in all the four regions studied. Age was significantly associated with AO and CO, but not with GO. Interpretation & conclusions: Prevalence of AO as well as of GO were high in India. Extrapolated to the whole country, 135, 153 and 107 million individuals will have GO, AO and CO, respectively. However, these figures have been estimated from three States and one UT of India and the results may be viewed in this light.

Risk Factors for Microvascular Complications of Diabetes Among South Indian Subjects with Type 2 Diabetes—The Chennai Urban Rural Epidemiology Study (CURES) Eye Study-5

BACKGROUND This study assessed the relationship between and risk factors for microvascular complications of diabetes in an urban South Indian type 2 diabetes population. METHODS Subjects with diabetes (n = 1,736) were selected from the population-based Chennai Urban Rural Epidemiology Study (CURES) Eye Study conducted on a representative population of Chennai city in south India. Four-field stereo retinal color photography was done, and diabetic retinopathy (DR) was classified according to the Early Treatment DR Study grading system. Neuropathy was diagnosed if the vibratory perception threshold of the big toe using biothesiometry was ≥ 20V. Overt nephropathy was diagnosed if the subjects had persistent macroalbuminuria (urinary albumin excretion ≥ 300 μg/mg of creatinine) and microalbuminuria if it was between 30 and 299 μg/mg of creatinine. Among the 1,715 subjects with gradable fundus photographs, 1,608 individuals who had information on all test parameters were included. RESULTS Overall, DR was present in 282 (17.5%), neuropathy in 414 (25.7%), overt nephropathy in 82 (5.1%), and microalbuminuria in 426 (26.5%) subjects. Eighteen subjects had all three microvascular complications of diabetes. The risk of nephropathy (odds ratio [OR] = 5.3, P<0.0001) and neuropathy (OR = 2.9, P<0.0001) was significantly higher among the subjects with sight-threatening DR compared to those without DR. Common risk factors identified for all the three microvascular complications of diabetes were age, glycated hemoglobin, duration of diabetes, and serum triglycerides. DR was associated with nephropathy after adjusting for age, gender, hemoglobin A1c, systolic blood pressure, serum triglycerides, and duration of diabetes (OR = 2.140, 95% confidence interval = 1.261-3.632, P = 0.005). CONCLUSIONS This is the first population-based study from India to report on all microvascular complications of diabetes and reveals that the association between DR and nephropathy is stronger than that with neuropathy.

Knowledge and awareness of diabetes in urban and rural India: The Indian Council of Medical Research India Diabetes Study (Phase I): Indian Council of Medical Research India Diabetes 4

Background: Representative data on knowledge and awareness about diabetes is scarce in India and is extremely important to plan public health policies aimed at preventing and controlling diabetes. Aim: The aim of the following study is to assess awareness and knowledge about diabetes in the general population, as well as in individuals with diabetes in four selected regions of India. Materials and Methods: The study subjects were drawn from a representative sample of four geographical regions of India, Chandigarh, Tamil Nadu, Jharkhand and Maharashtra representing North, South, East and West and covering a population of 213 million. A total of 16,607 individuals (5112 urban and 11,495 rural) aged ≥20 years were selected from 188 urban and 175 rural areas. Awareness of diabetes and knowledge of causative factors and complications of diabetes were assessed using an interviewer administered structured questionnaire in 14,274 individuals (response rate, 86.0%), which included 480 self-reported diabetic subjects. Results: Only 43.2% (6160/14,274) of the overall study population had heard about a condition called diabetes. Overall urban residents had higher awareness rates (58.4%) compared to rural residents (36.8%) (P < 0.001). About 46.7% of males and 39.6% of females reported that they knew about a condition called diabetes (P < 0.001). Of the general population, 41.5% (5726/13,794) knew about a condition called diabetes. Among them, 80.7% (4620/5726) knew that the prevalence of diabetes was increasing, whereas among diabetic subjects, it was 93.0% (448/480). Among the general and diabetic population, 56.3% and 63.4% respectively, were aware that diabetes could be prevented. Regarding complications, 51.5% of the general population and 72.7% diabetic population knew that diabetes could affect other organs. Based on a composite knowledge score to assess knowledge among the general population, Tamil Nadu had the highest (31.7) and Jharkhand the lowest score (16.3). However among self-reported diabetic subjects, Maharashtra had the highest (70.1) and Tamil Nadu, the lowest score (56.5). Conclusion: Knowledge and awareness about diabetes in India, particularly in rural areas, is poor. This underscores the need for conducting large scale diabetes awareness and education programs.

Associations of β-Cell Function and Insulin Resistance with Youth-Onset Type 2 Diabetes and Prediabetes Among Asian Indians

AIM This study examined β-cell function and insulin resistance (homeostasis model assessment-insulin resistance [HOMA-IR]) in Asian Indian youth with type 2 diabetes mellitus (T2DM-Y) and prediabetes. SUBJECTS AND METHODS Eighty-two subjects with non-insulin-requiring type 2 diabetes and age of onset below 25 years were recruited within 18 months of diagnosis and compared with age- and sex-matched subjects with prediabetes (n=31) and normal glucose tolerance (NGT) (n = 83). Body mass index (BMI) and waist circumference were measured, and blood samples were taken in the fasting state and after 30, 60, 90, and 120 min of an oral glucose load for assessment of plasma glucose and insulin levels. Insulin sensitivity/resistance measures was calculated by using the reciprocal of the fasting insulin, the HOMA-IR equation, and the composite whole body insulin sensitivity index (Matsuda Index), and β-cell function was calculated by the oral disposition index (DIo). RESULTS T2DM-Y and prediabetes subjects had higher BMI, waist circumference, and fasting insulin than NGT subjects (P<0.05 for each). The 30-min insulin levels were lower in T2DM-Y and higher in prediabetes subjects compared with NGT (57 and 140 vs. 129 μIU/mL, P<0.001). The T2DM-Y group had greater insulin resistance (HOMA-IR, 1.87 vs. 0.97; P<0.05) and lower β-cell function (DIo, 0.36 vs. 3.28; P<0.001) than NGT. In separate models, the Matsuda Index and DIo were independently associated with prediabetes and T2DM-Y (P<0.05). However, when both were included together, only DIo remained associated with T2DM-Y, whereas both DIo and Matsuda Index were associated with prediabetes (P<0.05). When controlled for adiposity (BMI and waist circumference), an association was observed but in opposite directions, with waist being positively associated with prediabetes (P = 0.016) and BMI negatively associated with T2DM-Y (P = 0.009). CONCLUSIONS Among Asian Indians, β-cell dysfunction appears to be more strongly associated with T2DM-Y than insulin resistance.

Prevalence and risk factors for diabetic retinopathy in Asian Indians with young onset Type 1 and Type 2 Diabetes

AIM To assess the prevalence and risk factors for diabetic retinopathy (DR) in people with young onset type 1 (T1DM-Y) and type 2 diabetes (T2DM-Y). METHODS T1DM-Y(n=150) and T2DM-Y(n=150) participants, age between 10 and 25 years at diagnosis, had a complete clinical evaluation, biochemical assessment, and four field digital retinal colour photography. The Early Treatment Diabetic Retinopathy Study grading system was used to grade DR. Proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME) were considered as sight threatening DR. RESULTS The prevalence of any DR was 53.3% [95% CI 45.3-61.3] in T1DM-Y (duration of diabetes: 12.4±7.4 years) and 52.7% [44.7-60.7] in T2DM-Y (11.8±8.3 years). The age and gender adjusted prevalence of DR, DME and PDR was 62.5%, 10% and 7.3% in T1DM-Y, whereas it was 65.8%,12.7% and 9.3% in T2DM-Y respectively. In multivariable logistic regression, diabetes duration [Odds ratio (OR) 1.99 per 5 years; CI 1.42-2.79], waist circumference [1.28 per 5 cm;1.05-1.56] and microalbuminuria [2.39 per 50 μg;1.07-5.31] were associated with DR in T1DM-Y, and diabetes duration [2.21 per 5 years; 1.61-3.02], diastolic blood pressure [1.54 per 5 mmHg;1.18-2.02], Glycated hemoglobin [1.37 per %;1.07-1.75] and lower stimulated C-peptide [1.54 per 0.5 pmol/ml;1.15-2.05;] were associated with DR in T2DM-Y. CONCLUSION Over half of the people with young-onset diabetes, regardless of type, have retinopathy within 10-12 years of diabetes duration, emphasizing the need for regular eye screening and aggressive control of glucose and blood pressure to prevent DR.

Prevalence of overweight and obesity among school children and adolescents in Chennai

ObjectivesTo determine the prevalence of overweight and obesity among children and adolescents in Chennai, India, using national and international age- and sex- specific body mass index (BMI) cut-off points.MethodsThe Obesity Reduction and Awareness and Screening of Non communicable diseases through Group Education in Children and Adolescents (ORANGE) project is a cross-sectional study carried out on 18,955 children (age 6–11 years) and adolescents (age 12–17 years) across 51 schools (31 private and 20 government) of Chennai. Overweight and obesity was classified by the International Obesity Task Force (IOTF 2000) and Khadilkar’s criteria (2012), and Hypertension by the IDF criteria (in children ≥10 years and adolescents).ResultsThe prevalence of overweight/obesity was significantly higher in private compared to government schools both by the IOTF criteria [private schools: 21.4%, government schools: 3.6%, (OR: 7.4, 95% CI:6.3–8.6; P<0.001) and by Khadilkar criteria (private school: 26.4%, government schools: 4.6% OR: 6.9, 95% CI:6.2–7.8; P<0.001). Overweight/obesity was higher among girls (IOTF: 18%, Khadilkar: 21.3%) compared to boys (IOTF: 16.2%, Khadilkar: 20.7%) and higher among adolescents (IOTF: 18.1%, Khadilkar: 21.2%) compared to children (IOTF: 15.5%, Khadilkar: 20.7%). Prevalence of hypertension was 20.4% among obese/overweight and 5.2% among non-obese (OR 4.7, 95%CI: 4.2–5.3, P<0.001).ConclusionThe prevalence of overweight and obesity is high among private schools in Chennai, and hypertension is also common.