Hypertension and insulin resistance in a native unindustrialised rural population of India

Prevalence, risk factors and complications associated with type 2 diabetes in migrant South Asians

It is estimated that type 2 diabetes (T2D) currently affects about 246 million people worldwide, with South Asians, especially Indians, having both the largest number of cases and the fastest growing prevalence. South Asian ethnicity has been identified as a major risk factor for the development of T2D with central adiposity, insulin resistance and an unfavourable lipid profile being identified as predominant signals of alarm. Leading databases, including Web of Science, Medline, PubMed and Science Direct, were consulted and manual searches were conducted for cited references in leading diabetes-related journals. In all, 152 articles were included for the final assessment reported in this review. Genetic predisposition, central adiposity and unfavourable lifestyle, including physical inactivity and an unhealthy diet, were associated with the prevalence of T2D in migrant South Asians. 'Westernization', acculturation, socio-economic factors and lack of knowledge about the disease have also been identified as contributors to the development of T2D in this population. Higher prevalence of T2D in migrant South Asians may not be entirely attributed to genetic predisposition; hence, ethnicity and associated modifiable risk factors need further investigation. Preventive measures and appropriate interventions are currently limited by the lack of ethnic-specific cut-off points for anthropometric and biological markers, as well as by the absence of reliable methods for dietary and physical activity assessment. This article describes the prevalence rate, risk factors and complications associated with T2D in migrant South Asians living in different countries.

Insulin sensitivity as a risk factor for common carotid intima media thickness (IMT): its relation to atherosclerosis

INTRODUCTION

The relationship between insulin resistance and atherosclerosis (ATH) in non-diabetic hypertensive patients from the Asian Indian population remains poorly understood. To resolve this issue, the present study was designed to analyze whether insulin sensitivity in a non-diabetic individual is related to the development of ATH.(by using IMT as an index) and whether this relationship is dependent on the presence of other cardiovascular disease (CVD) risk factors such as dyslipidemia and hypertension.

METHODOLOGY

This study included 68 healthy controls with no diabetes and hypertension and 41 hypertensive patients who underwent four-point oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT). A biochemical profile, beta mode ultrasonography for intima media thickness of carotid artery, and ECG determination was carried out.

RESULTS

Hypertensive patients in our study exhibited significantly increased abdominal obesity. Blood pressure, fasting and 2 hr plasma glucose (4.62 +/- 0.08 and 5.55 +/- 0.17 mmol/l), and triglyceride (1.47 +/- 0.067 mmol/l) levels were compared to those of control subjects (p < 0.05). The fasting insulin levels and HOMA-IR were also significantly increased and Composite Insulin Sensitivity Index (CISI) reduced compared to controls with p < 0.01. Intima media thickness of the left (0.08 +/- 0.01) and right (0.069 +/- 0.008) CA were both significantly increased in hypertensives (p < 0.01). Correlation analysis showed that IMT of the left carotid artery was significantly associated with triglyceride levels (r = 0.813, p < 0.05) but not with insulin measures such as HOMA-IR and CISI.

CONCLUSION

Hyperinsulinemia was observed in our non-diabetic hypertensive patients, but no association was found between IMT and insulin resistance. That IMT of hypertensives was associated with triglyceride levels suggests that high levels of insulin may be related to the development of ATH indirectly through its effects on lipid metabolism in our population.

Magnitude of dyslipedemia and its association with micro and macro vascular complications in type 2 diabetes: a hospital based study from Bikaner (Northwest India)

AIM

Type 2 diabetes is not only associated with hyperglycemia but also with disorders of lipid metabolism. The aim of this study was to investigate the association of dyslipedemia with micro and macro vascular complications of diabetes.

METHODS

Population based cross sectional study included 4067 diabetic patients who visited hospital during January 2000 to December 2002. Lipid profile was estimated by semi autoanalyser, Retinopathy was assessed by fundoscopy, Nephropathy by microalbuminurea, coronary artery disease (CAD) by electro cardiogram (ECG) changes, peripheral vascular disease (PVD) by doppler study and neuropathy by clinical examinations. The association of dyslipedemia with micro and macro vascular complications was assessed by regression analysis.

RESULTS

The prevalence of dyslipedemia is high in diabetic population with high serum cholesterol >240mg/dl was seen in 15%, serum triglycerides >160mg/dl was seen in 42.41%, raised LDL >130mg/dl in 45.26%, VLDL >40mg/dl in 24.09% and low levels of HDL-C <40mg/dl were seen in 52.27%. On regression analysis, CAD had strong correlation with high levels of VLDL (0.76), triglycerides (0.82), LDL (0.23) and low HDL (-0.81). Similar association was seen with PVD. Diabetic retinopathy and nephropathy were found to have significant correlation with low HDL (-0.43) and raised LDL (0.37), respectively. Neuropathy was not found to have any significant correlation with lipid profile abnormalities.

CONCLUSION

Lipid profile abnormalities are very common in type 2 diabetes and it has great influence on CAD and PVD. Hence, appropriate preventive and treatment strategies should be considered timely.

Acute Pulmonary Embolism on MDCT of the Chest: Prediction of Cor Pulmonale and Short-Term Patient Survival from Morphologic Embolus Burden

OBJECTIVE

To predict cor pulmonale and short-term outcome in patients with pulmonary embolism (PE), we retrospectively investigated three morphology-based MDCT systems for scoring pulmonary artery obstruction.

MATERIALS AND METHODS

Eighty-nine consecutive patients (51 men and 38 women; age range, 23-83 years; median, 63.3 years) with an MDCT diagnosis of acute PE were included in the study. Sixty-four patients had a coexisting malignancy. PE severity was assessed by two masked observers using three percentage arterial obstruction indexes: two severity scores adapted from conventional angiography (excluding and including arterial branch obstruction grading: scores A and B, respectively) and a CT-derived severity score (index C). Echocardiographic reports were reviewed for elevation of right ventricular pressure. Obstruction index results were analyzed for correlation with pulmonary artery pressures and for prediction of cor pulmonale and 30-day survival. Statistical analysis included kappa, analysis of variance, linear correlation, chi-square, and logistic regression tests.

RESULTS

Kappa values of 0.89, 0.82, and 0.78 were obtained for interobserver agreement on PE severity for indexes A, B, and C, respectively. PE severity was moderate but varied significantly between the scores (for index A: median, 25.0%; range, 6.3-100; for index B: median, 12.5%; range, 3.1-65.6; for index C: median, 7.1%; range, 0.65-65.8; p < 0.0001 [analysis of variance]). Index C correlated best with pulmonary artery pressures (r = 0.69; p < 0.0016) and the presence of cor pulmonale (p = 0.0051; odds ratio [OR], 1.20/percentage increase [95% confidence interval, 1.05-1.35]; for an index C cutoff of 21.3%: p = 0.0001; positive predictive value, 1; negative predictive value, 0.87). Eight patients died within 30 days after CT. The PE severity of indexes A and B was not associated with patient outcome (p > 0.05). With score C, PE severity was a significant predictor of early death (p = 0.018; OR, 1.03/percentage increase [95% confidence interval, 1.00-1.06]; for an index C cutoff of 21.3%: p = 0.018; overall OR, 6.77; positive predictive value, 0.24; negative predictive value, 0.96).

CONCLUSION

Mastora score was a significant predictor of cor pulmonale and short-term outcome and may therefore allow therapy and risk stratification in patients with acute PE.

Sib-recruitment for studying migration and its impact on obesity and diabetes

BACKGROUND

Urban-rural comparisons are of limited relevance in examining the effects of urban migration in developing countries where urbanisation is due to growth of existing urban populations, expansion of urban boundaries, and rural in-migration. Cultural, genetic and life-style backgrounds of migrants and host populations further limit the value of rural-urban comparisons. Therefore we evaluated a sib-comparison design intended to overcome the limitations of urban-rural comparisons.

METHODS

Using the framework of a current cardiovascular risk factor screening study conducted in Indian factories, we recruited the non-migrant rural sibs of migrant urban factory workers and the urban sibs of non-migrant factory workers. The response rate, completed interviews and examinations conducted were assessed. Adequacy of generic food frequency questionnaires and WHO quality of life questionnaire were assessed.

RESULTS

All the urban factory workers and spouses approached agreed to be interviewed. Of the 697 participants interviewed, 293 (42%) had at least one rural dwelling sibling. Twenty (22%) siblings lived further than 100 km from the study site. An additional 21 urban siblings of non-migrant factory workers were also investigated to test the logistics of this element of the study. Obesity (BMI >25 kg/m2) was more common in rural sibs than urban factory workers (age adjusted prevalence: 21.1% (17.1 to 25.0) vs. 16.1% (11.9, 20.3). Diabetes prevalence (fasting plasma glucose greater than 126 mg/dl) was higher than expected (age-adjusted prevalence: 12.5% (22 out of 93) in urban migrants and 4.5% (8 out of 90) in rural non-migrant sibs.

CONCLUSION

The sib-comparison design is robust and has been adopted in the main study. It is possible that simple urban-rural study designs under-estimate the true differences in diabetes risk between migrants and non-migrants.

Prevalence of metabolic syndrome in an Indian urban population

OBJECTIVES

To determine prevalence of the metabolic syndrome using United States Adult Treatment Panel-3 (ATP-3) guidelines in an urban Indian population.

METHODS

Randomly selected adults >20 years were studied using stratified sampling. Target study sample was 1800 with population proportionate distribution (men 960, women 840). Evaluation of anthropometric variables, blood pressure, fasting blood glucose and lipids was performed. Subjects (1123; response 62.4%) were examined, fasting blood samples were available in 1091 (532 men, 559 women) and analysed for prevalence of metabolic syndrome. Atherosclerosis risk factors were determined using the current guidelines. Metabolic syndrome was diagnosed when any three of the following were present: central obesity, raised triglycerides >/=150 mg/dl (>/=1.7 mmol/l), low high-density lipoprotein (HDL) cholesterol, blood pressure >/=130/>/=85 mm Hg, and diabetes or fasting glucose >110 mg/dl (>6.1 mmol/l). Intergroup comparisons were performed using t-test or chi-square test.

RESULTS

Metabolic syndrome was present in 345 (31.6%) subjects; prevalence was 122 (22.9%) in men and 223 (39.9%) in women (p<0.001); the age-adjusted prevalence was 24.9%, 18.4% in men and 30.9% in women. There was a significant age-related increase in its prevalence (Mantel-Haenzel chi(2) for trend p<0.05). Prevalence of components of metabolic syndrome in men and women was: central obesity (waist, men >102 cm, women >88 cm) in 116 (25.6%) and 246 (44.0%); low HDL cholesterol (men<40 mg/dl, <1.0 mmol/l), women<50 mg/dl, <1.3 mmol/l) in 292 (54.9%) and 504 (90.2%); high triglycerides >/=150 mg/dl (>/=1.7 mmol/l) in 172 (32.3%) and 160 (28.6%); and impaired fasting glucose or diabetes in 90 (16.9%) and 90 (16.1%). The prevalence of physical inactivity, hypertension, hypercholesterolemia (>/=200 mg/dl, >/=5.2 mmol/l) and high LDL cholesterol (>/=130 mg/dl, >/=3.4 mmol/l) was greater in the metabolic syndrome group in both men and women (p<0.05).

CONCLUSIONS

There is a high prevalence of metabolic syndrome in an urban Indian population. Focus of cardiovascular prevention should be at this high-risk group.

Insulin resistance syndrome (metabolic syndrome) and obesity in Asian Indians: evidence and implications

OBJECTIVES

This review describes prevalence, determinants, and possible pathophysiologic mechanisms and suggests management and research directions for insulin resistance syndrome (metabolic syndrome) in Asian Indians.

METHOD

We reviewed the topic using the terms Asian Indians, Asians, South Asians, and Indians coupled with the terms insulin resistance, hyperinsulinemia, metabolic syndrome, and obesity from the databases Pubmed (National Library of Medicine, Bethesda, MD, USA) and Current Contents (Institute for Scientific Information, Thomson Scientific, Philadelphia, PA, USA) and from non-indexed publications of the medical research and governmental institutions in India.

RESULTS

Asian Indians have a high prevalence of insulin resistance syndrome that may underlie their greater than normal tendency to develop diabetes mellitus and early atherosclerosis. Important reasons could be their excess body fat and adverse body fat patterning including abdominal adiposity even when the body mass index is within the currently defined normal limits. Some of these features have been reported at birth and childhood. Whether Asian Indians also have tendency to develop insulin resistance de novo, independent of total or regional adiposity, needs further investigation. Underlying genetic tendency or early-life adverse events may contribute to such a phenotype, but lifestyle factors alone or modulated by inherited factors appear to play an important role because obesity and dyslipidemia become worse with urbanization and migration. Systemic stress may contribute to insulin resistance syndrome in the intra-country and inter-country migrant Asian Indians.

CONCLUSIONS

High prevalences of excess body fat, adverse body fat patterning, hypertriglyceridemia, and insulin resistance beginning at a young age have been consistently recorded in Asian Indians irrespective of their geographic locations. These data suggest that primary prevention strategies should be initiated early in this ethnic group.

Prevalence of diabetes, impaired fasting glucose and insulin resistance syndrome in an urban Indian population

OBJECTIVE

Epidemiological study among urban subjects in western India to determine prevalence of diabetes, insulin resistance syndrome (IRS) and their risk factors.

METHODS

Randomly selected adults > or =20 years were studied using stratified sampling. Target sample was 1,800 (men 960, women 840). 1123 subjects (response 62.4%) were evaluated and blood samples were available in 532 men and 559 women (n=1091, 60.6%). Measurement of anthropometric variables, blood pressure, fasting blood glucose and lipids was performed. Atherosclerosis risk factors were determined using current guidelines. Diabetes was diagnosed when the subject was a known diabetic or fasting blood glucose was > or =126 mg/dl, impaired fasting glucose (IFG) diagnosed when fasting glucose was 110-125 mg/dl. IRS was diagnosed when any three of-IFG, high triglycerides >150 mg/dl, low HDL cholesterol (men<40 mg/dl, women<50 mg/dl), central obesity (men>102 cm, women>88 cm), or high normal blood pressure (>130/>85 mmHg) or hypertension-were present.

RESULTS

Diabetes was present in 70 men (13.2%) and 64 women (11.5%). Age-adjusted prevalence of diabetes was 9.3% in men (95% confidence intervals (CI) 6.7-11.8), 8.1% in women (CI 5.8-10.4) and 8.6% overall (CI 6.9-10.3). IFG was in 28 men (5.3%) and 29 women (5.2%). IRS was present in 52 men (9.8%) and 114 women (20.4%) with age-adjusted prevalence of 7.9% in men (CI 6.7-9.1) and 17.5% in women (CI 14.4-20.6) with an overall prevalence of 12.8% (CI 10.8-14.8). Other metabolic abnormalities of IRS in men and women were high triglycerides in 32.1 and 28.6%, low HDL cholesterol in 54.9 and 90.2%; central obesity in 21.8 and 44.0%, and high normal blood pressure or hypertension in 35.5 and 32.4%. IFG subjects had similar atherosclerosis risk factor profile as normal subjects while those with IRS and diabetes had significantly greater prevalence of obesity, central obesity, hypertension, high triglycerides and low HDL (P<0.01).

CONCLUSIONS

There is s significant prevalence of diabetes and IRS in this urban Indian population. Subjects with diabetes as well as IRS have greater prevalence of obesity, central obesity, hypertension, hypertriglyceridemia and low HDL as compared with normal subjects.

New CT index to quantify arterial obstruction in pulmonary embolism: comparison with angiographic index and echocardiography

OBJECTIVE

This study was designed to define and evaluate a specific index to quantify arterial obstruction with helical CT in acute pulmonary embolism.

MATERIALS AND METHODS

Fifty-four patients (mean age, 56 years) with proven pulmonary emboli among 158 consecutive patients, who had undergone both CT and pulmonary angiography for clinically suspected pulmonary embolism, were eligible for the study. The CT obstruction index was defined as (n. d) (n, value of the proximal clot site, equal to the number of segmental branches arising distally; d, degree of obstruction scored as partial obstruction [value of 1] or total obstruction [value of 2]). We compared the CT obstruction index with pulmonary arterial obstruction on angiography (assessed by the Miller index), using linear regression, and correlated it with findings on echocardiography. Interobserver variability was determined for both CT and pulmonary angiography indexes.

RESULTS

The CT obstruction index (29% +/- 17%) and the Miller index (43% +/- 25%) were well correlated (r = 0.867, p < 0.0001) with an excellent concordance between investigators for both the CT index (r = 0.944, p < 0.0001) and the Miller index (r = 0.904, p < 0.0001). A CT obstruction index greater than 40% identified more than 90% of patients with right ventricular dilatation.

CONCLUSION

The degree of arterial obstruction in pulmonary embolism may be quantified by a specific CT index that appears reproducible and highly correlated to the previously described index with pulmonary angiography. Further evaluations are needed to investigate the usefulness of the CT obstruction index for stratification of patient risk and determining therapeutic options.