Temporal changes in prevalence of type 2 diabetes and impaired glucose tolerance in urban southern India

Evolving Landscape of Diabetes Epidemic in Southeast Asia: Insights from National Family Health Survey

Background

Limited evidence on diabetes prevalence trends from the Indian subcontinent prompted this study to estimate the trends in diabetes prevalence using the National Family Health Survey (NFHS) data.

Method

A cross-sectional survey carried out between 2015-2016 (NFHS-4) and 2019-2021 (NFHS-5) in a nationally representative sample of adults (aged 20 to 54 years) was used. Diabetes was defined as the presence of: diagnosed diabetes (self-reported), fasting plasma glucose (FPG) ≥ 126 mg/dl, or a random plasma glucose (RPG) ≥200 mg/dl. "Fasting" was defined as the last food intake >8 hours and "random" as irrespective of the last meal. Diagnosed diabetes was defined as the presence of "self-reported diabetes" and undiagnosed diabetes was defined as FPG > 126 mg/dl or RPG ≥200 mg/dl.

Findings

The crude prevalence of total diabetes increased from 3.5% (95% confidence interval (CI): 3.46-3.55) in 2015-2016 to 3.99% (95% CI: 3.94-4.04) in 2019-2021, a relative change of 14%. The increase was more in the poorest (1.77% vs 2.48%; P < 0.001) as compared to the rich (5.35%% vs· 5.43%; P = 0.847), rural areas (2.71% vs 3.38%; P < 0.001) as compared to urban (4.95% vs. 5.26%; P = 0.051), in normal weight individuals (1.87% vs. 2.16%; P < 0.001) as compared to obese (7.12% vs. 7.03%; P = 0.384).

Interpretation

While the absolute prevalence of diabetes is highest amongst individuals residing in urban areas belonging to the rich wealth centile, the relative increase in the prevalence is disproportionately higher in those residing in rural areas, belonging to the poorest wealth centiles and having normal weight.

District-level heterogeneity in overweight or obesity among women of reproductive age: A geo-spatial analysis in India

BACKGROUND

Globally by 2030, 38% of the world's population would be overweight, and another 20% would be obese. This has led to rising concerns regarding how swiftly and substantially the world is moving towards this epidemic of "globesity". India too is facing an increased burden of overweight and obese population. The changing dietary patterns are significantly associated with the increasing prevalence of overweight/obesity and related complications, especially among women. Hence, the present study aims to observe the spatial patterns of overweight or obesity among women in reproductive age group in India and factors associated with it.

METHODS

The study analyzed data from a cross-sectional nationwide household survey, i.e. National Family Health Survey (NFHS-4), 2015-16. The primary outcome variable of this study was overweight/obesity among reproductive-age women, which was measured through the body mass index (BMI) of the women. Bivariate and multivariate logistic regression analysis was used to analyze the data. Additionally, for spatial analysis in terms of overweight/obesity among women in India, univariate and bivariate Moran's I index measurements were used along with the usage of spatial regression models.

RESULTS

The value of spatial-autocorrelation for overweight or obese was 0.64, which depicts the moderately high prevalence of the overweight/obesity coverage over districts of India. The overall prevalence overweight/obesity among women in India is around 25% and higher proportion of women from urban areas (37.8%), and non-poor (33.4%) economic group reported to be overweight or obese. From spatial lag model, the lag coefficient was found to be 0.28, implying that a change in the prevalence of overweight/obesity among women in a certain district may statistically lag the prevalence of overweight/obesity by 28% in the neighbouring districts. There were significantly high clustering of overweight/obese women and non-poor wealth quintiles in 132 districts, mainly from states of Punjab, Haryana, Gujarat, Maharashtra, Kerala, Tamil Nadu, Karnataka and Andhra Pradesh. Additionally, there was high-high clustering of overweight/obese women and those who ever had caesarean in 82 districts, mostly from Kerala, Tamil Nadu, Andhra Pradesh and Karnataka.

CONCLUSION

The spatial patterns on the prevalence of overweight and obesity in India show that the women belonging to the southern states' districts are more overweight or obese in comparison to other states. The determinants like older age, higher education, urban residence, higher economic status are the key factors contributing to the prevalence of overweight or obesity among women in the reproductive age group. The study concludes and recommends an urgent need of interventions catering to urban women belonging to higher socio-economic status, to reduce the risks of health consequences due to overweight and obesity.

Inequalities in overweight and obesity among reproductive age group women in India: evidence from National Family Health Survey (2015-16)

Background

In developing nations like India, fertility and mortality have decreased, and diseases related to lifestyle have become more common. Females in India are more prone to being overweight and obese than their male counterparts, more specifically in affluent families than the poor ones. Understanding the overweight and obesity trend may help develop feasible public health interventions to reduce the burden of obesity and associated adverse health outcomes.

Methods

The study utilizes the fourth round of the National Family Health Survey (NFHS-4), 2015–16. Descriptive statistics, bivariate and multivariate analysis was used to check the significant relationship between overweight and obesity, and other background characteristics. Income-related inequality in overweight and obesity among women was quantified by the concentration index and the concentration curve. Further, Wagstaff decomposition analysis was done to decompose the concentration index, into the contributions of each factor to the income-related inequalities.

Results

Overweight & obesity among women had a significant positive association with their age and educational level. The odds of overweight and obesity were 57% more likely among women who ever had any caesarean births than those who did not [AOR: 1.57; CI: 1.53–1.62]. The likelihood of overweight and obesity was 4.31 times more likely among women who belonged to richest [AOR: 5.84; CI: 5.61–6.08] wealth quintile, than those who belonged to poor wealth quintile. Women who ever terminated the pregnancy had 20% higher risk of overweight and obesity than those who did not [AOR: 1.20; CI: 1.17–1.22]. The concentration of overweight and obesity among women was mostly in rich households of all the Indian states and union territories. Among the geographical regions of India, the highest inequality was witnessed in Eastern India (0.41), followed by Central India (0.36).

Conclusion

The study results also reveal a huge proportion of women belonging to the BMI categories of non-normal, which is a concern and can increase the risks of developing non-communicable diseases. Hence, the study concludes and recommends an urgent need of interventions catering to urban women belonging to higher socio-economic status which can reduce the risks of health consequences due to overweight and obesity. Development nutrition-specific as well as sensitive interventions can be done for mobilization of local resources that addresses the multiple issues under which a woman is overweight or obese.

Association of Acanthosis Nigricans and Acrochordon with Insulin Resistance: A Cross-Sectional Hospital-Based Study from North India

Background

Insulin resistance (IR) is a pre-diabetic condition and has been reported in patients with acanthosis nigricans (AN) and acrochordon. AN and acrochordon are claimed to be cutaneous markers of IR.

Aim

The purpose of this paper was to study the association of AN and acrochordon with IR.

Methods

It was a cross-sectional hospital-based study. Both groups were assessed for IR by using homeostatic model assessment of insulin resistance (HOMA-IR) formula.

Results

A total of 70 cases and an equal number of controls were studied. IR was observed more in cases (41.4%) compared to controls (17.1%) (P < 0.01). Mean HOMA-IR value was also significantly higher in cases (4.32 ± 4.44) compared to controls (2.27 ± 0.90) (P < 0.05).

Limitations

Low number of cases and controls were taken in the study. Association with hyperlipidemia and metabolic syndrome was not elicited.

Conclusions

AN and acrochordons were found to be associated with IR.

Urban environment as an independent predictor of insulin resistance in a South Asian population

Background

Developing countries, such as India, are experiencing rapid urbanization, which may have a major impact on the environment: including worsening air and water quality, noise and the problems of waste disposal. We used health data from an ongoing cohort study based in southern India to examine the relationship between the urban environment and homeostasis model assessment of insulin resistance (HOMA-IR).

Methods

We utilized three metrics of urbanization: distance from urban center; population density in the India Census; and satellite-based land cover. Restricted to participants without diabetes (N = 6350); we built logistic regression models adjusted for traditional risk factors to test the association between urban environment and HOMA-IR.

Results

In adjusted models, residing within 0–20 km of the urban center was associated with an odds ratio for HOMA-IR of 1.79 (95% CI 1.39, 2.29) for females and 2.30 (95% CI 1.64, 3.22) for males compared to residing in the furthest 61–80 km distance group. Similar statistically significant results were identified using the other metrics.

Conclusions

We identified associations between urban environment and HOMA-IR in a cohort of adults. These associations were robust using various metrics of urbanization and adjustment for individual predictors. Our results are of public health concern due to the global movement of large numbers of people from rural to urban areas and the already large burden of diabetes.

Electronic supplementary material

The online version of this article (10.1186/s12942-019-0169-9) contains supplementary material, which is available to authorized users.

Incidence of type 2 diabetes mellitus and prediabetes in Kerala, India: results from a 10-year prospective cohort

Background

Kerala, the southern state of India, has experienced sudden rise in the prevalence estimates of diabetes. A cohort study on the incidence of type 2 diabetes mellitus (T2DM) in Kerala state thus aptly bridges the lacuna of incidence estimate of T2DM from a population at risk.

Methods

A 10-year prospective cohort study was carried out in two urban wards of central Kerala. The individuals who participated in the baseline survey in 2007 were again invited for a follow-up study in 2017. The data was analyzed using IBM SPSS Statistics for windows (version 21.0). Logistic regression analysis was used to estimate odds ratios and 95% confidence intervals. Findings are based on the 10-year follow-up data from 869 participants from the cohort.

Results

The overall follow-up and response rate of the study was 68.9 and 86.9% respectively. During the follow-up period, 190 people (21.9%) developed T2DM. The incidence rate of T2DM and impaired fasting glucose (IFG) were 24.5 per 1000 person years and 45.01 per 1000 person years respectively. Nearly 60% of participants with baseline IFG were converted to T2DM group in the follow-up period. Age > 45 years, family history of T2DM, BMI ≥ 25 kg/m² and presence of central obesity emerged as important risk factors for incident T2DM.

Conclusion

High incidence of prediabetes over diabetes observed in this study shows an epidemic trend of T2DM in Kerala, India. It requires an immediate public health action.

Acanthosis nigricans: A screening test for insulin resistance - An important risk factor for diabetes mellitus type-2

Background:

Acanthosis nigricans (AN) is one of the signs suggestive of high insulin resistance (IR). IR is one of the mechanisms involved in pathogenesis of diabetes mellitus type-2 (DM Type-2). Thus, early detection of IR in children may allow us time to intervene well before the development of DM Type-2. In this study, 62% of children having AN had high IR. In children having both, AN and high body mass index (BMI), the incidence of IR was about 80%. This suggests that these easily detectable parameters alone can be useful in screening children at high risk of developing DM Type-2 in future. These simple criteria thus hold promise for use in high throughput screening programs for diabetes.

Context:

A pilot study conducted by the authors showed that children with AN have a high incidence of IR. The detection of IR in children may allow us time to intervene well before the development of DM Type-2. Detection of DM Type-2 by hyperglycemia may be too late to prevent the onset of microvascular changes.

Aims:

This study aims to determine whether easily observable presence of AN can be used to screen for increased IR in children, and thereby to detect this important risk factor for DM Type-2.

Settings and Design:

Cross-sectional, observational study. Two schools, one with children belonging to average economic background and the other, a residential school with children of affluent parents. Selection of children was done randomly.

Subjects and Methods:

The study was conducted among 507 children in the age group of 10–18 years. Physical examination for the detection of AN, height and weight measurements, waist circumference, fasting plasma glucose, fasting plasma insulin, and lipid profile was done. Homeostatic model assessment of insulin resistance was calculated.

Statistical Analysis Used:

Data analysis was performed using descriptive statistics and inferential statistical methods. The association between categorical variables was done by Chi-square test.

Results:

The presence of AN positively correlated with high IR, and when combined with increased BMI, the incidence rate of IR is 80%.

Conclusions:

AN can be used as a screening method to identify children at risk of DM Type-2-since those who have high IR have a high possibility of having DM Type-2 in future. Hence, early screening and simple, but effective interventional strategies can be instituted at this age, which may prevent or delay diabetes in the long run.

Low economic status is identified as an emerging risk factor for diabetes mellitus in korean men aged 30 to 59 years in korean national health and nutrition examination survey 2008 to 2010

BACKGROUND

We compared the association between economic status and the prevalence of diabetes mellitus (DM) using large nationwide datasets covering the previous 10 years in Korea.

METHODS

We analyzed the association between economic status and DM using Korean National Health and Nutrition Examination Survey (KNHANES) data from 2001 to 2010 weighted to represent the Korean population between 30 and 59 years of age. The economic status of participants was classified into quartiles according to monthly family income with an equivalence scale.

RESULTS

In men, the prevalence of diabetes in the lowest income quartile (Q1) was significantly higher than that in the other quartiles in 2008 (age and body mass index-adjusted odds ratio [OR], 1.846; 95% confidence interval [CI], 1.126 to 3.027; P=0.015), 2009 (OR, 1.706; 95% CI, 1.094 to 2.661; P=0.019), and 2010 (OR, 1.560; 95% CI, 1.024 to 2.377; P=0.039) but not in 2001 or 2005. The data indicated that classification in the lowest economic status was an independent risk factor for diabetes even after adjusting for abdominal obesity, dyslipidemia, hypertension and education level in men of KNHANES 2008 to 2010. Although economic status was significantly associated with abdominal obesity, hypertriglyceridemia, and hypertension in women (P<0.001), there was no significant association between economic status and DM in women.

CONCLUSION

Korean men between 30 and 59 years of age with the lowest economic status had a significantly higher prevalence of DM in 2008 to 2010 even after adjusting for other risk factors.

The incidence and prevalence of diabetes mellitus and related atherosclerotic complications in Korea: a National Health Insurance Database Study

AIMS/INTRODUCTION

The incidence and prevalence of type 2 diabetes mellitus (T2DM) and related macrovascular complications in Korea were estimated using the Health Insurance Review and Assessment (HIRA) database from 2007-2011, which covers the claim data of 97.0% of the Korean population.

MATERIALS AND METHODS

T2DM, coronary artery disease (CAD), cerebrovascular disease (CVD), and peripheral artery disease (PAD) were defined according to ICD-10 codes. We used the Healthcare Common Procedure Coding System codes provided by HIRA to identify associated procedures or surgeries. When calculating incidence, we excluded cases with preexisting T2DM within two years before the index year. A Poisson distribution was assumed when calculating 95% confidence intervals for prevalence and incidence rates.

RESULTS

The prevalence of T2DM in Korean adults aged 20-89 years was 6.1-6.9% and the annual incidence rates of T2DM ranged from 9.5-9.8/1,000 person-year (PY) during the study period. The incidence rates of T2DM in men and women aged 20-49 years showed decreasing patterns from 2009 to 2011 (P<0.001); by contrast, the incidence in subjects aged 70-79 years showed increased patterns from 2009 to 2011 (P<0.001). The incidence rates of CAD and CVD in patients newly diagnosed with T2DM were 18.84/1,000 PY and 11.32/1,000 PY, respectively, in the year of diagnosis. Among newly diagnosed individuals with T2DM who were undergoing treatment for PAD, 14.6% underwent angioplasty for CAD during the same period.

CONCLUSIONS

Our study measured the national incidences of T2DM, CAD, CVD, and PAD, which are of great concern for public health. We also confirmed the relatively higher risk of CAD and CVD newly detected T2DM patients compared to the general population in Korea.

Comparison of relative waist circumference between Asian Indian and US adults

BACKGROUND

Relative to Europeans, Asian Indians have higher rates of type 2 diabetes and cardiovascular disease. Whether differences in body composition may underlie these population differences remains unclear.

METHODS

We compared directly measured anthropometric data from the Chennai Urban Rural Epidemiology Study (CURES) survey of southern Indians (I) with those from three US ethnic groups (C: Caucasians, A: African Americans, and M: Mexican Americans) from NHANES III (Third National Health and Nutrition Examination Survey). A total of 15,733 subjects from CURES and 5,975 from NHANES III met inclusion criteria (age 20-39, no known diabetes).

RESULTS

Asian Indian men and women had substantially lower body mass index, waist circumference, hip circumference, waist-to-hip ratio, and body surface area relative to US groups (P values <0.0001). In contrast, the mean (±se) waist-weight ratio was significantly higher (P < 0.001) in I (men 1.35 ± 0.002 and women 1.45 ± 0.002) than in all the US groups (1.09, 1.21, and 1.14 in A, M, and C men; 1.23, 1.33, and 1.26 in A, M, and C women (se ranged from 0.005 to 0.006)).

CONCLUSIONS

Compared to the US, the waist-weight ratio is significantly higher in men and women from Chennai, India. These results support the hypothesis that Southeast Asian Indians are particularly predisposed toward central adiposity.

Type 2 diabetes in Asians: prevalence, risk factors, and effectiveness of behavioral intervention at individual and population levels

This review summarizes the current data on diabetes risk factors, prevalence, and prevention efforts in Asia and Asian migrant populations. Studies indicate that type 2 diabetes mellitus is a large and growing threat to public health in Asian populations. Furthermore, Asian subgroups (e.g., South Asians/Asian Indians, Chinese) have unique risk factor profiles for developing diabetes, which differ from other populations and between Asian ethnic groups. Lifestyle intervention programs are effective in preventing diabetes in Asians, as with other ethnicities. The strength of these findings is lessened by the lack of systematically collected data using objective measurements. Large epidemiologic studies of diabetes prevalence and risk factor profiles and translational trials identifying sustainable and culturally acceptable lifestyle programs for Asian subgroups are needed.

IFSO-APC consensus statements 2011

Associations of BMI with body composition and health outcomes may differ between Asian and European populations. Asian populations have also been shown to have an elevated risk of type 2 diabetes, hypertension, and hyperlipidemia at a relatively low level of BMI. New surgical indication for Asian patients should be discussed by the expert of this field. Forty-four bariatric experts in Asia-Pacific and other regions were chosen to have a voting privilege for IFSO-APC Consensus at the 2nd IFSO-APC Congress. A computerized audience-response voting system was used to analyze the agreement with the sentence of the consensus. Of all delegates, 95% agreed with the necessity of the establishment of IFSO-APC consensus statements, and 98% agreed with the necessity of a new indication for Asian patients. IFSO-APC Consensus statements 2011. Bariatric surgery should be considered for the treatment of obesity for acceptable Asian candidates with BMI ≥ 35 with or without co-morbidities. Bariatric/GI metabolic surgery should be considered for the treatment of T2DM or metabolic syndrome for patients who are inadequately controlled by lifestyle alternations and medical treatment for acceptable Asian candidates with BMI ≥ 30. The surgical approach may be considered as a non-primary alternative to treat inadequately controlled T2DM, or metabolic syndrome, for suitable Asian candidates with BMI ≥ 27.5. Other eight sentences are agreed with by majority of the voting delegates to form IFSO-APC consensus statements. This will help to make safe and wholesome the progress of bariatric and metabolic surgery in Asia.

Prevalence and trends of the diabetes epidemic in South Asia: a systematic review and meta-analysis

Background

Diabetes mellitus has reached epidemic proportions worldwide. South Asians are known to have an increased predisposition for diabetes which has become an important health concern in the region. We discuss the prevalence of pre-diabetes and diabetes in South Asia and explore the differential risk factors reported.

Methods

Prevalence data were obtained by searching the Medline® database with; ‘prediabetes’ and ‘diabetes mellitus’ (MeSH major topic) and ‘Epidemology/EP’ (MeSH subheading). Search limits were articles in English, between 01/01/1980–31/12/2011, on human adults (≥19 years). The conjunction of the above results was narrowed down with country names.

Results

The most recent reported prevalence of pre-diabetes:diabetes in regional countries were; Bangladesh–4.7%:8.5% (2004–2005;Rural), India–4.6%:12.5% (2007;Rural); Maldives–3.0%:3.7% (2004;National), Nepal–19.5%:9.5% (2007;Urban), Pakistan–3.0%:7.2% (2002;Rural), Sri Lanka–11.5%:10.3% (2005–2006;National). Urban populations demonstrated a higher prevalence of diabetes. An increasing trend in prevalence of diabetes was observed in urban/rural India and rural Sri Lanka. The diabetes epidemicity index decreased with the increasing prevalence of diabetes in respective countries. A high epidemicity index was seen in Sri Lanka (2005/2006–52.8%), while for other countries, the epidemicity index was comparatively low (rural India 2007–26.9%; urban India 2002/2005–31.3%, and urban Bangladesh–33.1%). Family history, urban residency, age, higher BMI, sedentary lifestyle, hypertension and waist-hip ratio were associated with an increased risks of diabetes.

Conclusion

A significant epidemic of diabetes is present in the South Asian region with a rapid increase in prevalence over the last two decades. Hence there is a need for urgent preventive and curative strategies .

Rising burden of obesity in Asia

Overweight and obesity have reached epidemic proportions in many Asian countries. These countries also face a grave burden of obesity-related disorders such as diabetes, hypertension, and cardiovascular diseases, which develop at a younger age than in Western populations. These disorders are also manifested in childhood. The major causative factors are related to the lifestyle changes occurring due to rapid socioeconomic transition. Asian populations show several differences in genetic factors when compared with the white population, and they also have lower cut points for environmental risk factors. National programmes targeting public awareness, education and improved structural facilities to facilitate healthy lifestyle are the keys to alleviate the economic and health care burden of the obesity-related disorders.

The effect of rural-to-urban migration on obesity and diabetes in India: a cross-sectional study

BACKGROUND

Migration from rural areas of India contributes to urbanisation and may increase the risk of obesity and diabetes. We tested the hypotheses that rural-to-urban migrants have a higher prevalence of obesity and diabetes than rural nonmigrants, that migrants would have an intermediate prevalence of obesity and diabetes compared with life-long urban and rural dwellers, and that longer time since migration would be associated with a higher prevalence of obesity and of diabetes.

METHODS AND FINDINGS

The place of origin of people working in factories in north, central, and south India was identified. Migrants of rural origin, their rural dwelling sibs, and those of urban origin together with their urban dwelling sibs were assessed by interview, examination, and fasting blood samples. Obesity, diabetes, and other cardiovascular risk factors were compared. A total of 6,510 participants (42% women) were recruited. Among urban, migrant, and rural men the age- and factory-adjusted percentages classified as obese (body mass index [BMI] >25 kg/m(2)) were 41.9% (95% confidence interval [CI] 39.1-44.7), 37.8% (95% CI 35.0-40.6), and 19.0% (95% CI 17.0-21.0), respectively, and as diabetic were 13.5% (95% CI 11.6-15.4), 14.3% (95% CI 12.2-16.4), and 6.2% (95% CI 5.0-7.4), respectively. Findings for women showed similar patterns. Rural men had lower blood pressure, lipids, and fasting blood glucose than urban and migrant men, whereas no differences were seen in women. Among migrant men, but not women, there was weak evidence for a lower prevalence of both diabetes and obesity among more recent (

CONCLUSIONS

Migration into urban areas is associated with increases in obesity, which drive other risk factor changes. Migrants have adopted modes of life that put them at similar risk to the urban population. Gender differences in some risk factors by place of origin are unexpected and require further exploration. Please see later in the article for the Editors' Summary.

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Key Words Collapse

MESH Headings

• Adolescent
• Adult
• Aged
• Cross-Sectional Studies
• Diabetes Mellitus/epidemiology
• Female
• Humans
• India/epidemiology
• Male
• Middle Aged
• Obesity/epidemiology
• Population Dynamics
• Risk Factors
• Socioeconomic Factors
• Young Adult

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Grants

• Wellcome Trust
• 084674 Wellcome Trust
• G0600705 Medical Research Council
• GR070797MF Wellcome Trust

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Affiliation(s)

Shah Ebrahim Department of Epidemiology & Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom.
Sanjay Kinra
Liza Bowen
Elizabeth Andersen
Yoav Ben-Shlomo
Tanica Lyngdoh
Lakshmy Ramakrishnan
R C Ahuja
Prashant Joshi
S Mohan Das
Murali Mohan
George Davey Smith
Dorairaj Prabhakaran
K Srinath Reddy

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High prevalence of diabetes and cardiovascular risk factors associated with urbanization in India

OBJECTIVE

To compare prevalence of diabetes, impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and cardiovascular risk factors between a city, a town, and periurban villages (PUVs) in southern India and to look for temporal changes in the city and PUVs.

RESEARCH DESIGN AND METHODS

Subjects aged >/=20 years were studied in Tamilnadu, India, in Chennai (city, n = 2,192; 1,053 men and 1,138 women), Kanchipuram (town, n = 2,290; 988 men and 1,302 women), and Panruti (PUVs, n = 2,584; 1,280 men and 1,304 women) in 2006. Demographic, socioeconomic, and anthropometric details; blood pressure; physical activity; diet habits; and lipids were studied. Risk associations with diabetes were analyzed using multiple logistic regression analyses. Present and previous data in the city and the PUVs were compared.

RESULTS

Mean BMI, waist circumference, and family history of diabetes were significantly lower in the PUVs. The PUVs had a lower prevalence of diabetes (9.2 [95% CI 8.0-10.5], P < 0.0001) than the city (18.6 [16.6-20.5]) and town (16.4 [14.1-18.6]). Approximately 40% of subjects were newly diagnosed. Prevalence of impaired glucose tolerance (IGT) was higher (P < 0.0001) in the city (7.4 [6.2-8.5]) than in the town (4.3 [3.3-5.3]) and the PUVs (5.5 [4.6-6.5]). Prevalence of IFG was generally low. Age, family history, and waist circumference were significantly associated with diabetes, while physical activity was not. Overweight, elevated waist circumference, hypertension, and dyslipidemia were more prevalent in the city.

CONCLUSIONS

In the city, diabetes increased from 13.9 to 18.6% in 6 years and IGT decreased significantly. The town and city had similar prevalences; the PUVs had lower diabetes prevalence, but prevalence had increased compared with that in a previous survey. Cardiometabolic abnormalities were more prevalent in urban populations.

Migration and its impact on adiposity and type 2 diabetes

In this review, we discuss the impact of migration on the incidence and prevalence of obesity and type 2 diabetes mellitus (T2DM) in different ethnic groups and populations. We also analyze the determinants of such phenomena in view of the global increase in the migration and escalating prevalence of obesity and T2DM. The risk escalation of the obesity and T2DM followed a gradient, as migrants (Blacks, Hispanics, Chinese, South Asians, etc.) became more affluent and urbanized, indicating an important role of environmental factors. A stepwise increase in the prevalence of obesity in Blacks along the path of migration (5% in Nigeria, 23% in Jamaica, and 39% in the United States) is a classic example. Furthermore, South Asian migrants, who are particularly predisposed to develop insulin resistance and T2DM, showed nearly four times prevalence rates of T2DM than rural sedentee populations. Similar observations were also reported in intracountry migrants and resettled indigenous populations. The determinants were found to include nutrition transition, physical inactivity, gene-environment interaction, stress, and other factors such as ethnic susceptibility. However, certain contradictory trends were also seen in some migrant communities and have been explained by various phenomena such as healthy migrant effect, "salmon bias", and adherence to traditional diets. A review of the evidence suggests a critical role of environmental factors in conferring an increased risk of obesity and T2DM. The important contributory factors to this phenomenon were urbanization, mechanization, and changes in nutrition and lifestyle behaviors, but the role of stress and as yet unknown factors remain to be determined.

Diabetes and tuberculosis: the impact of the diabetes epidemic on tuberculosis incidence

Background

Tuberculosis (TB) remains a major cause of mortality in developing countries, and in these countries diabetes prevalence is increasing rapidly. Diabetes increases the risk of TB. Our aim was to assess the potential impact of diabetes as a risk factor for incident pulmonary tuberculosis, using India as an example.

Methods

We constructed an epidemiological model using data on tuberculosis incidence, diabetes prevalence, population structure, and relative risk of tuberculosis associated with diabetes. We evaluated the contribution made by diabetes to both tuberculosis incidence, and to the difference between tuberculosis incidence in urban and rural areas.

Results

In India in 2000 there were an estimated 20.7 million adults with diabetes, and 900,000 incident adult cases of pulmonary tuberculosis. Our calculations suggest that diabetes accounts for 14.8% (uncertainty range 7.1% to 23.8%) of pulmonary tuberculosis and 20.2% (8.3% to 41.9%) of smear-positive (i.e. infectious) tuberculosis.

We estimate that the increased diabetes prevalence in urban areas is associated with a 15.2% greater smear-positive tuberculosis incidence in urban than rural areas – over a fifth of the estimated total difference.

Conclusion

Diabetes makes a substantial contribution to the burden of incident tuberculosis in India, and the association is particularly strong for the infectious form of tuberculosis. The current diabetes epidemic may lead to a resurgence of tuberculosis in endemic regions, especially in urban areas. This potentially carries a risk of global spread with serious implications for tuberculosis control and the achievement of the United Nations Millennium Development Goals.

Epidemic obesity and type 2 diabetes in Asia

The proportions of people with type 2 diabetes and obesity have increased throughout Asia, and the rate of increase shows no sign of slowing. People in Asia tend to develop diabetes with a lesser degree of obesity at younger ages, suffer longer with complications of diabetes, and die sooner than people in other regions. Childhood obesity has increased substantially and the prevalence of type 2 diabetes has now reached epidemic levels in Asia. The health consequences of this epidemic threaten to overwhelm health-care systems in the region. Urgent action is needed, and advocacy for lifestyle changes is the first step. Countries should review and implement interventions, and take a comprehensive and integrated public-health approach. At the level of primary prevention, such programmes can be linked to other non-communicable disease prevention programmes that target lifestyle-related issues. The cost of inaction is clear and unacceptable.

Low risk threshold for acquired diabetogenic factors in Asian Indians

India is facing an epidemic of type 2 diabetes, with high prevalence in urban areas. Urbanisation and associated life style changes adversely affect the risk factors for diabetes unmasking the high genetic tendency existing in the population. Various epidemiological studies in Indians have shown that the increasing prevalence of diabetes could be attributed to a high genetic risk and lower risk thresholds for acquired risk factors such as age, obesity, abdominal adiposity and a high percentage of body fat. Diabetes occurs at a younger age in Indians compared to Whites. The risk of diabetes increases with a body mass index (BMI) of >23 kg/m(2) and waist circumference of 85 cm for men and 80 cm for women in Asian Indians. For a given BMI, Asian Indians have higher central adiposity. There is also evidence of higher insulin resistance amongst Indians, and this is partly explained by higher body fat percentage. A large proportion of urban adults has the metabolic syndrome also which predisposes them to both diabetes and cardiovascular diseases. Recognition of these conditions and institution of early preventive measures are urgently needed.

Trends in waist circumference among U.S. adults

OBJECTIVE

Waist circumference has been proposed as a measure of obesity or as an adjunct to other anthropometric measures to determine obesity. Our objective was to examine temporal trends in waist circumference among adults in the U.S.

RESEARCH METHODS AND PROCEDURES

We used data from 15,454 participants >/=20 years old in National Health and Nutrition Examination Survey (NHANES) III (1988 to 1994) and 4024 participants >/=20 years old from National Health and Nutrition Examination Survey 1999 to 2000.

RESULTS

The unadjusted waist circumference increased from 95.3 (age-adjusted, 96.0 cm) to 98.6 (age-adjusted, 98.9 cm) cm among men and from 88.7 (age-adjusted 88.9 cm) to 92.2 (age-adjusted 92.1 cm) cm among women. The percentiles from the two surveys suggest that much of the waist circumference distribution has shifted. Statistically significant increases occurred among all age groups and racial or ethnic groups except men 30 to 59 years old, women 40 to 59 and >/=70 years old, and women who were Mexican American or of "other" race or ethnicity.

DISCUSSION

These results demonstrate the rapid increase in obesity, especially abdominal obesity, among U.S. adults. Unless measures are taken to slow the increase in or reverse the course of the obesity epidemic, the burden of obesity-associated morbidity and mortality in the U.S. can be expected to increase substantially in future years.

The burden of type 2 diabetes: are we doing enough?

Increasing levels of obesity, arising from energy-rich diets and sedentary lifestyles, are driving a global pandemic of type 2 diabetes. The prevalence of type 2 diabetes worldwide is set to increase from its present level of 150 million, to 225 million by the end of the decade and to as many as 300 million by 2025. Shocking as they are, these figures represent only clinically diagnosed diabetes, and many more cases of diabetes remain undiagnosed and untreated. In addition, up to one-quarter of western populations have impaired glucose tolerance or the dysmetabolic syndrome, which are considered to represent pre-diabetic states. Type 2 diabetes is appearing increasingly in children and adolescents, and the frequency of diagnosis of paediatric type 2 diabetes is outstripping that of type 1 diabetes in some areas. The long-term complications associated with type 2 diabetes carries a crushing burden of morbidity and mortality, and most type 2 diabetic patients die prematurely from a cardiovascular event. Diabetic patients are more than twice as costly to manage as non-diabetic patients, due mainly to the high costs associated with management of diabetic complications. Indeed, diabetes care already accounts for about 2-7% of the total national health care budgets of western European countries. Controlling the type 2 diabetes epidemic will require changes to the structure of healthcare delivery. Well-resourced interventions will be required, with effective co-ordination between all levels of government, health care agencies, multidisciplinary health care teams, professional organisations, and patient advocacy groups. Above all, intervention is needed today.

Metabolic syndrome in urban Asian Indian adults--a population study using modified ATP III criteria

AIMS/HYPOTHESIS

To determine the prevalence of the Metabolic syndrome (MetS) using modified ATP III criteria in urban Asian Indian adults.

METHODS

475 subjects (age 20-75 years) from a population data base were studied for the MetS using ATP III criteria but with a modified waist circumference (WC) appropriate for Indians. Presence of >or=3 of the following; raised WC (Men >or=90 cm, Women >or=85 cm), triglycerides (TG) >or=1.7 mmol/l), HDL-Cholesterol (HDL-C)-<1.0 mmol/l for men, <1.3 mmol/l for women, fasting plasma glucose (FPG)>or=6.1 mmol/l and blood pressure (BP)>or=130/>or=85 mm of Hg, or using BP medication, indicated the MetS. Insulin resistance (IR) was calculated using the Homeostasis Model Assessment (HOMA) equation. Factor analysis was used to identify clusters of correlated abnormalities.

RESULTS

MetS was present in 41.1%. WC was increased in 31.4%, TG in 45.6%, low HDL-C in 65.5%, hypertension in 55.4% and raised FPG 26.7%. MetS was present in 27.9% of subjects with FPG<6.1 mmol/l and its prevalence increased to >70% with higher FPG values. MetS was more common in women than in men (46.5 vs. 36.4%, chi(2)=4.6, P=0.03) and in older people. Four distinct clusters of abnormalities were identified with some gender variations. IR was more prevalent in MetS and was a component of two clusters but it was not a core component in factor analysis.

CONCLUSIONS

MetS is common in Asian Indians. Its prevalence is age-related, and is more common in women. HOMA-IR or fasting plasma insulin was not a core component of the MetS.