Prevalence of Risk Factors of Diabetes Among Urban Poor South Indian Population

OBJECTIVE

The objective of the study was to assess the prevalence of risk factors of diabetes among urban poor population in Chennai, Tamil Nadu, South India.

STUDY AND METHODS

A cross-sectional study was conducted from Dec-2010 to Feb-2011 in Chennai city. Five hundred twenty-nine subjects aged above 18 years (409 women and 120 men) habitants of three slums were randomly selected. A structured questionnaire was used to collect the socio-demographic and clinical information. Anthropometric measures, blood pressure and random blood glucose (RCBG) estimation were done. Dietary intake was assessed using 24-hour diet recall and duration of physical activity/day in all components was recorded.

RESULTS

The mean age and BMI of the study population was 45.4±12.8 years and 25.8±4.9 kg/m2 respectively. About 20.4% were illiterate and 34.8% were either unemployed, retired or housewives. Median family income per month was 3000 INR. Prevalence of obesity (≥25 kg/m2) was 57.3% and central obesity (≥90 cms in male and ≥80 cms in female) was 75.7%. The median duration spent in walking, standing and sitting were 30, 120, and 240 minutes/day respectively. There was a gross inadequacy in vegetable intake. The prevalence of self-reported diabetes and hypertension was 20.8% and 24.2%, respectively. Among the subjects without a previous diagnosis of diabetes, 12.5% had RCBG ≥140 mgs. 10.6% were diagnosed with hypertension.

CONCLUSIONS

Sedentarism coupled with unhealthy diet pattern are the major contributing factors for the higher prevalence of diabetes and hypertension in urban poor population.

Direct costs associated with chronic kidney disease among type 2 diabetic patients in India

The aim of this study was to estimate the direct costs of medical care among hospitalized type 2 diabetic patients with chronic kidney disease (CKD). A total of 209 (M:F, 133:76) patients were divided into groups based on the severity of kidney disease. Group 1 subjects had undergone renal transplantation (n = 12), group 2 was CKD patients on hemodialysis (n = 45), group 3 was patients with CKD, prior to end-stage renal disease (ESRD) (n = 66), and group 4 (n = 86) consisted of subjects without any complications. Details about expenditure per hospitalization, length of stay during admission, direct medical and nonmedical cost, expenditure for the previous two years, and source of bearing the expenditure were recorded in a questionnaire. Diabetic patients with CKD prior to ESRD spend more per hospitalization than patients without any complications. [Median ₹ 12,664 vs. 3,214]. The total median cost of CKD patients on hemodialysis was significantly higher than other CKD patients (INR 61,170 vs. 12,664). The median cost involved in kidney transplantation was ₹ 392,920. The total expenditure for hospital admissions in two years was significantly higher for dialysis than transplantation. Patients on hemodialysis or kidney transplantation tend to stay longer as inpatient admissions. The source of funds for the expenditure was mainly personal savings (46%). The expenditure on hospital admissions for CKD was considerably higher, and so, there is a need to develop a protocol on a cost-effective strategy for the treatment of CKD.

Effect of diabetes on treatment outcome of smear-positive pulmonary tuberculosis--a report from South India

AIM

To assess the effect of diabetes on tuberculosis (TB) treatment outcome and sputum conversion among new smear-positive (NSP) cases registered under Directly Observed Treatment Short Course in South India.

METHODS

Details on sputum conversion and TB treatment outcome were collected from case records of NSP cases (N = 332; M/F 247:85) registered at TB units of three districts in Tamil Nadu. Subjects were screened for diabetes and categorized as diabetic (TBDM) (n = 96; 73:23) and non-diabetic (TBnonDM) (n = 149; 109:40).

RESULTS

Among 245 selected TB patients, 93.5% were cured, 1.6% completed TB treatment, 2% had TB treatment failure (TF), and 0.4% had treatment default (TD), 0.4% with MDR-TB and 2% death rate. At the end of intensive phase of TB treatment, 14.7% remained sputum positive in the TBDM group, whereas it was 3.5% in the TBnonDM group. Mean duration (days) for sputum conversion was higher in the TBDM group (64.2 ± 10.5) compared to the TBnonDM group (61.5 ± 7.5) (p<0.001). TF rate was higher (4.2% vs 0.7%) and MDR-TB (1%) was also seen in the TBDM group. No death and TD were seen among DM whereas it was 3.4 and 0.7% in TBnonDM.

CONCLUSIONS

Delayed sputum conversion and high TB treatment failure rates were common in NSP cases with diabetes.

Incidence of cardiovascular diseases and associated risk factors among subjects with type 2 diabetes - an 11-year follow up study

Aims

This study was planned to assess the development of cardiovascular disease (CVD) events over an 11-year period and to identify the associated risk factors that could predict the onset of CVD among subjects with type 2 diabetes.

Methods

Retrospective data of 249 patients (M:F 149:100) with type 2 diabetes, from a cohort of 7800 patients, attending a tertiary care center for diabetes from January 2000 to December 2011 were retrieved and analyzed for this study. Sociodemographic and habitual risk factors, baseline diabetes duration, HbA1c and time of onset of CVD and its risk factors were collected from case records. Person-years method was used to calculate incident rate of CVD. Binary logistic regression analyses were done to identify predictors associated with CVD and its risk factors.

Results

Incidence of CVD among subjects with diabetes was 5.6 cases/1000 person-years. Nearly 60% developed hypertension and dyslipidemia or both during the 11-year period. The most common complication was neuropathy (14.4%). Smoking [OR (95%CI)] [9.26 (1.6–54.9)] (p = 0.014) and heavy alcohol consumption [8.7 (1.1–69.8)] (p = 0.04) were significantly associated with CVD. Higher BMI was significantly associated with hypertension and dyslipidemia [2.4 (1.3–4.3)] (p = 0.003).

Conclusions

Smoking and heavy alcohol consumption were significantly associated with CVD, and increased BMI was significantly associated with hypertension and dyslipidemia among subjects with type 2 diabetes in this study population. These findings emphasize the need for early identification and modification of risk factors associated with CVD events in patients with diabetes.

Phylogeny of Indian rhizophoraceae based on the molecular data from chloroplast tRNA(LEU)UAA intergenic sequences

Molecular identification data of unexplored Indian Rhizophoraceae an eco-friendly mangroves are an imperative aspect in molecular phylogenetics. We describe the phylogenetic relationships among the Rhizophoraceae genus Rhizophora, Ceriops and Bruguiera using tRNA Leu (UAA) intron sequences as a molecular marker. The results of present study reveals congeneric relationship between R. apiculata, R. mucronata, B. gymnorhiza indicating a high degree of gene flow within them and the pairwise distribution of study plants among Rhizophoraceae family. The phylogram constructed using tRNA Leu sequence clearly clustered the species of the same genus in individual group. The stem-loop could be divided into two classes, both built up from two base pairing heptanucleotide repeats. Size variation was primarily caused by different numbers of repeats but some strains also contained additional sequences in this stem-loop. The statistical summaries of DNA sequence data can enable to identify the structural signature of the genome as well as to classify phylogenetic relationships among different species reflected in the difference of genetic diversity distributions within their DNA sequences.

Direct organogenesis of seaside heliotrope (Heliotropium crassavicum) using stem explants

Heliotropium crassavicum L. is a sand binder salt marsh herb with enormous traditional value and widely found in South Asia America and Europe. In the direct method of regeneration from stem explants, we observed the maximum number of shoot regeneration after four weeks culture of MS elongation medium with 2.0 mg L(-1) of 2, 4-D (17.27 +/- 0.51). It was clear that MS medium with 2.0 mg mL(-1) 2, 4-D alone suitable for shoot multiplication as well as shoot elongation then compared to other combination of auxin and cytokinin. In vitro shoots were excised from shoot clumps and transferred to rooting medium containing 2, 4-dichlorophenoxy acetic acid (0.5-3.0 mg L(-1)). The maximum number of root regeneration (6.4 +/- 0.416) and root length (6.08 +/- 0.07) were observed in MS rooting medium fortified with 2.5 mg L(-1) of 2, 4-D after 2 weeks of culture. 85% of in vitro raised plantlets with well-developed shoots and roots were transferred to ex vivo conditions into polythene bag containing sterile compost with ratio (v/v/v) of organic fertilizer: sand: peat (1:2:2; 3:1:0 or 2:2:1). Sixty five percent of acclimated plants were transferred to the pots under full sun where they grew well without any detectable phenotypic variations.

Antidiabetic effect of a black mangrove species Aegiceras corniculatum in alloxan-induced diabetic rats

Earlier ethnopharmacological records divulged the traditional usages of mangrove Aegiceras corniculatum (Linn.) Blanco distributed in coastal and estuarine areas of Southeast India. Excluding scientific knowledge of A. corniculatum against diabetes an upgrowing endocrinal disorder, our present study evaluated the effect on alloxan-induced diabetic rats. Diabetes was induced in adult rats of the Wistar strain by intraperitoneal injection of alloxan monohydrate. The experimental rats were administered with leaf suspension of A. corniculatum post orally using an intragastric tube. On completion of the 60-day treatment, a range of biochemical parameters were tested including liver hexokinase, glucose-6phosphatase and fructose 1, 6 bisphosphatase in the liver of control and allaxon-diabetic rats. As a result, A. corniculatum leaf suspension showed moderate reduction in blood glucose (from 382 ± 34 to 105 ± 35), glycosylated hemoglobin, a decrease in the activities of glucose-6 phosphatase and fructose 1, 6-bisphosphatase, and an increase activity of liver hexokinase achieved through the oral administration of extract on 100 mg/kg. The present findings support promising results in terms of antidiabetic activities establishing its candidacy for further purification of individual compound in order to understand their mechanism of action.

Prevalence of lower urinary tract infection in South Indian type 2 diabetic subjects

This study was done to determine the prevalence of lower urinary tract infection (UTI), the causative pathogens, their antimicrobial pattern, and the recurrence of infection in type 2 diabetic subjects. A total of 1157 (M: F 428: 729) type 2 diabetic subjects were selected for this study. Midstream urine specimens were collected and the culture tests were done by a quantitative method whereas antimicrobial sensitivity was determined by using the Kirby-Bauer method. A significant colony count was seen in 495 (42.8%) subjects and an insignificant count in 350 (30.3%) subjects; there were a few cases of recurrent UTI. Women (47.9%) had a significantly higher prevalence of UTI than men (34.1%) (χ² = 20.3, P < 0.0001). Except for BMI, UTI was significantly associated with age, duration of diabetes, and poor glycemic control in both sexes. About 533 pathogens of gram positive and gram negative bacilli were isolated from 495 subjects in this study. Escherichea coli (E. coli) was the most commonly found organism. Gram negative pathogens were found to be highly sensitive to sulbactum / cefoperazone and piperacillin / tazobactum. The prevalence of UTI was significantly higher in women than men with E. coli being the major isolated pathogen. Gram negative pathogens were highly sensitive to sulbactum / cefoperazone and piperacillin / tazobactum.

Risk of future diabetes is as high with abnormal intermediate post-glucose response as with impaired glucose tolerance

AIMS

This analysis was done to compare the risk of development of diabetes among subjects with impaired glucose tolerance (IGT) and early glucose intolerance (EGI; intermediary post glucose level > or = 160 mg/dl) when compared with normal (NGT). Profile of insulin secretion and insulin resistance was compared in a subgroup of subjects with EGI, IGT and diabetes.

PATIENTS AND METHODS

A program on 'primary prevention of diabetes' was initiated and high risk subjects were encouraged to join the program and were followed up. Out of 4084 (M:F 2344:1740) subjects enrolled in the program, a total of 1659 (M:F 1044:615) subjects with mean age 41.3 +/- 10.2 years who had at least two follow up visits were selected for this analysis. OGTTs were performed once in every 6 months. The median follow up duration was 5 years. The conversion rate to diabetes in subjects with persistent IGT or EGI was determined. In a subgroup of subjects, NGT (n = 118), IGT (n = 68), EGI (n = 106) and new DM (n = 126), plasma insulin at fasting, 30 min and 2 hr were measured and insulin resistance (HOMA-IR) was calculated by HOMA method. Insulinogenic index (DeltaI/G) was also calculated.

RESULTS

The rate of conversion of IGT 251 (40.5%) and EGI 210 (36.5%) subjects to diabetes was similar and significantly higher when compared with the NGT subjects 99 (21.3%). Similar results were noted both in men and women. By using ROC procedure, a cut - off value of one hour post glucose of > or = 160 mg/dl gave a sensitivity of 80% and specificity of 70% to detect abnormal glucose tolerance. In a subset of subjects studied, it was noted that subjects with EGI had significantly higher fasting insulin values than NGT. Insulin resistance (IR) was the highest in DM [Geometric mean (SD)] 6.6 (1.9)), followed by EGI (4.5 (2.3)) (p < 0.0001 vs NGT, 2.9 (2.4)) and IGT (3.9 (2.2)). Insulinogenic index was normal in EGI, NGT and IGT, and it was lower in DM in comparison with other groups. The multiple logistic regression analysis showed that EGI (odds ratio (OR) 2.11) and development of diabetes was strongly associated. The survival curve (time free from diabetes) showed that the median survival time for NGT, EGI and IGT were 18.7, 11.6 and 9.6 yrs respectively.

CONCLUSION

EGI which is a distinct entity with abnormal intermediate glucose response in glucose tolerance test (GTT) appears to be a risk factor similar to IGT in the development of diabetes. They had higher insulin resistance with normal insulin secretion. Therefore, it is important to determine the intermediate value also during the GTT in addition to fasting and 2 hr post glucose values.

Metabolic syndrome does not increase the risk of conversion of impaired glucose tolerance to diabetes in Asian Indians--Result of Indian diabetes prevention programme

AIMS

In this study, we assessed for the prevalence of metabolic syndrome (MetS) in the cohort of subjects with impaired glucose tolerance (IGT) in the Indian Diabetes Prevention Programme and studied whether the syndrome enhanced the conversion to diabetes.

METHODS

Effectiveness of lifestyle modification (LSM), metformin (Met) and LSM plus Met was tested in a randomised, controlled primary prevention study in subjects with IGT n=502 (M:W 397:105) at a median follow up of 30 months. Baseline prevalence of MetS was calculated using the WHO criteria. Insulin resistance (IR) was calculated using homeostasis model assessment (HOMA) method.

RESULTS

MetS was present in 233 subjects (46.4%; 95% CI 41.9-50.9) in the total group, in men (n=168; 42.3%; 95% CI 37.4-47.3) and in women (n=65; 61.9%; 95% CI 51.9-71.2) (men versus women chi(2)=12.8, p=0.0005). Insulin resistance (HOMA-IR>or=4.1) was present in 69.1% with no gender difference. IR increased proportionately with increasing number of abnormalities, in IGT (39.8%), IGT plus one abnormality (56.5%) and IGT plus any two or more abnormalities (69.1%) (Mantel Haenszel chi(2)=22.8, p<0.0001). Incidence of diabetes was similar in subjects with (40.3%) (n=94/233) or without (40.1%) (n=108/269) MetS (p=0.97). Cox's regression analysis confirmed that MetS did not enhance the conversion rate of IGT to diabetes both in the control (HR=0.88, 95% CI 0.53-1.47, p=0.63) and in the total group (HR=1.02, 95% CI 0.78-1.35, p=0.88), after correcting for effects of intervention.

CONCLUSION

Prevalence of MetS is high in Asian Indian IGT subjects, especially in women. However, it did not influence the rate of conversion of IGT to diabetes.

Insulin secretion and action show differences in impaired fasting glucose and in impaired glucose tolerance in Asian Indians

BACKGROUND

The aim of the study was to compare the abnormalities in insulin secretion and insulin sensitivity in impaired fasting glucose (IFG) and in impaired glucose tolerance (IGT).

METHODS

Glucose tolerance was determined by oral glucose tolerance test in 289 non-diabetic subjects selected for this study (M : F, 160 : 129, mean age 42.2 +/- 11.0 (SD) years, mean body mass index (BMI) 24.9 +/- 4.2 kg/m(2)). Diabetic subjects were excluded from the study. The association of insulin resistance and beta-cell function (calculated by HOMA model) with IFG and IGT was studied using linear and multiple logistic regression analyses. Subjects with normoglycaemia (NGT) were used as controls.

RESULTS

Insulin resistance was significantly more in IFG and in IGT than in NGT. beta-cell dysfunction was significantly higher in IFG than in IGT. IFG was associated with both insulin resistance (OR = 9.11, p < 0.001) and beta-cell dysfunction (inverse correlation, OR = 0.103, p < 0.001), while only insulin resistance was significantly associated with IGT (OR = 1.24, p = 0.005).

CONCLUSIONS

In urban South Asian Indians, IFG differed from IGT in having combined insulin resistance and beta-cell dysfunction, while IGT was associated only with insulin resistance.

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.

Impaired fasting glucose and impaired glucose tolerance in urban population in India

AIMS

To study prevalence of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) in urban Indians and their demographic and anthropometric characteristics.

METHODS

Data on capillary blood glucose (OGTT), anthropometric and demography details were available in 10 025 subjects (M : F 4711 : 5314) aged > or = 20 years. Glucose tolerance was categorized as normal, isolated IFG, isolated IGT, IFG + IGT and diabetes using the fasting and 2-h blood glucose (2hBG; 75-g glucose load) values. Subjects with known diabetes were excluded.

RESULTS

Age-standardized prevalences of IFG, IGT and newly detected diabetes were 8.7%, 8.1% and 13.9%, respectively. IFG was more prevalent in women (9.8%) than in men (7.4%) (chi2 = 13.62, P = 0.0002), while the gender differences in IGT (men 8.4%, women 7.9%) and diabetes (men 13.3%, women 14.3%) were not significant. Body mass index and waist circumference were higher in glucose-intolerant groups than in normal glucose tolerance (NGT). Prevalence of diabetes, IGT and IFG + IGT increased with age. Among the IFG, 4% had diabetes and 27.1% had IGT using 2hBG criteria. In IFG, the fasting and 2hBG values were not correlated.

CONCLUSIONS

Prevalences of IFG and IGT were similar in urban Indians and an overlap occurred in only less than half of these subjects. IFG was more common in women. Subjects with IFG were older and had more adverse anthropometric characteristics in comparison with NGT. IFG did not show an increasing trend with age.

Plasma homocysteine concentration and coronary artery disease in Asian Indians

OBJECTIVE

This study was done (a) to evaluate the relationship between the plasma total homocysteine (tHcy) levels and coronary artery disease (CAD) in Asian Indians and (b) to see the relationship between tHcy and glucose intolerance.

METHODS

Fasting concentrations of plasma tHcy was measured in 137 men, aged > or = 25 years who underwent coronary angiography while investigating for chest pain. Among them 71 had no CAD and 66 had CAD. Fasting plasma glucose (FPG) and glycosylated haemoglobin (HbA1c) were estimated. Total Hcy was measured using the Elisa method (Axis Biochemicals ASA-Oslo, Norway) in fasting EDTA plasma.

RESULTS

The subjects with CAD were significantly older but had similar body mass index (BMI), waist-hip ratio (WHR), FPG and HbA1c values compared with the non-CAD subjects (P < 0.001). The median tHcy and the percentages of abnormal values were similar in non-CAD and CAD groups. No significant differences were seen in the four subgroups with respect to the mean tHcy or the percentage of abnormal values. The highest tHcy values were seen in the non-diabetic, non-CAD group (group 1--control).

CONCLUSION

This preliminary data indicates that tHcy concentrations are not elevated in subjects with CAD and probably there is no association between total homocysteine and CAD in Indians. Homocysteine values were not influenced by the glucose tolerance status. Measurement of homocysteine concentrations may be more appropriate when the blood levels of vitamin B12 and folate are also measured.

Is increased apolipoprotein B-A major factor enhancing the risk of coronary artery disease in type 2 diabetes?

OBJECTIVES

An association of Apolipoprotein B (Apo B) with coronary artery disease (CAD) independent of LDL cholesterol (LDLc) concentrations has been reported in white population. This analysis was taken up to study whether the higher CAD risk in Asian Indians with diabetes could be explained by possible alterations in Apo B and Apolipoprotein A1 (Apo A1) concentrations.

METHODS

The study group consisted of four hundred and forty seven men aged > or = 25 years, 167 with CAD and 280 with no CAD, classified by coronary angiography. Plasma lipid profile including total cholesterol, LDLc, Apo A1 and Apo B were done. Glucose tolerance was evaluated in all.

RESULTS

Age, BMI, Apo B, and Apo A1 were significantly associated with CAD in a multiple regression analysis. Hyper Apo B was more common than hyper LDLc in CAD (73.6% vs 20.4%, chi2 = 157, P < 0.001). Apo B concentrations were increased in diabetic subjects even in the presence of normal levels of LDLc and in the absence of CAD.

CONCLUSIONS

The study has shown that the apolipoproteins B and A1 provide better information regarding the risk of CAD. Apo B abnormalities exist in large percentages of CAD subjects despite having normal levels of LDLc. Diabetes per se enhances the Apo B concentrations and this could probably be one of the mechanisms of accelerated CAD in diabetes. Hyper Apo B may be an index of CAD risk.

Lack of association of insulin resistance and carotid intimal medial thickness in non-diabetic Asian Indian subjects

OBJECTIVE

Atherosclerosis is associated with insulin resistance (IR) and dyslipidaemia. Impaired glucose tolerance (IGT) is characterised by IR and is associated with a higher risk of atherosclerosis. The objective of the present study was to test whether early atherosclerosis indicated by intimal medial thickness (IMT) of common carotid artery (CCA) and internal carotid artery (ICA) is higher in IGT than in normoglycaemic subjects (NGT) and to look for an association of IMT with IR and dyslipidaemia.

STUDY DESIGN AND METHODS

Ninety-nine randomly selected non-diabetic subjects aged >or=35 years (48 NGT and 51 IGT) were studied. Measurements of body mass index (BMI), waist/hip ratio (WHR), blood pressure, cholesterol-total, HDL, LDL, VLDL, triglycerides (TG), lipoprotein (a), apolipoprotein-A1 (Apo A1) and apolipoprotein-B (Apo B) and ratio of Apo A1/Apo B were estimated. Insulin resistance (HOMA-IR) was calculated using the fasting plasma insulin and glucose values. IMT of CCA and ICA were measured using high-resolution beta-mode ultrasonography.

RESULTS

Subjects with IGT and NGT were matched for BMI and WHR; HOMA-IR was higher in IGT vs NGT (7.92+/-4.2 vs 6.07+/-3.76, p = 0.028). Age-adjusted IMT values were similar in NGT and IGT (CCA 0.59+/-0.17 and 0.63+/-0.22 mm and ICA 0.44+/-0.10 and 0.45+/-0.10 mm, respectively). Further analyses were done in the total group. Multiple linear regression analyses showed that CCA-IMT was significantly associated with age and negatively associated with Apo A1/Apo B ratio. ICA-IMT was associated with age only. IMT was significantly correlated with cholesterol-total and LDL-cholesterol and apolipoproteins. It was not associated with IR.

CONCLUSION

In southern Indians, IGT did not influence the IMT. Although insulin resistance was higher in IGT, it was not associated with higher IMT. Conventional risk factors such as cholesterol, LDL-cholesterol and apolipoproteins showed association with IMT in the insulin-resistant population.

Association of proinsulin and insulin resistance with coronary artery disease in non-diabetic south Indian men

AIMS

To evaluate the association of plasma proinsulin and insulin resistance (IR) with coronary artery disease (CAD) in non-diabetic subjects.

METHODS

In this case control study, 41 normoglycaemic men with angiographic evidence of CAD were compared with 41 control men matched for age and glycaemia and with no history or evidence of cardiac diseases. Estimations of plasma glucose, lipids, fasting plasma specific insulin (SI) and proinsulin (PI) were performed. IR was calculated by the homeostasis model assessment (HOMA) method. Multiple logistic regression analysis was performed to test the association of the variables with the prevalence of CAD.

RESULTS

Subjects with CAD had a higher body mass index (BMI) (25.4 +/- 4.3 vs. 22.9 +/- 3.2 kg/m2, P = 0.003) and waist to hip ratio (WHR) (0.95 +/- 0.05 vs. 0.89 +/- 0.09, P = 0.001) and a lower high-density lipoprotein (HDL) cholesterol level (0.97 +/- 0.2 vs. 1.1 +/- 0.2 mmol/l, P = 0.002). They also had higher mean SI values (107.5 vs. 62.3 pmol/l, P = 0.002), PI values (19.3 vs. 5.7 pmol/l, P < 0.0001), PI/SI ratios (21.4 vs. 10.3, P < 0.0001) and HOMA IR (4.2 vs. 2.4, P = 0.004) compared with non-CAD subjects. These variables were associated with CAD in the unadjusted multiple regression analysis. In the multiple regression with the forward entry of the variables, WHR and PI only showed independent association with CAD.

CONCLUSIONS

Subjects with CAD had higher levels of obesity and WHR. CAD showed an association with low HDL cholesterol, circulating PI, PI/SI ratios and IR.

Risk variables for coronary artery disease in Asian Indians

No large study from India has addressed the association of risk variables with coronary artery disease (CAD) in angiographically proved cases. In this study, we analyzed the association of anthropometric variables, lipoproteins, and coagulation parameters with CAD in those cases proved by coronary angiography. A cross-sectional study of 447 men > or = 25 years old, classified as with CAD or without CAD, was performed. Men treated with aspirin or lipid-lowering agents, and those with renal, hepatic, or thyroid diseases were excluded. Associations of these variables with CAD were evaluated by univariate and multiple logistic regression analyses. The effect of diabetes on the CAD profile was also analyzed. Prevalences of diabetes and hypertension were significantly higher among those with CAD (p <0.001 for both). Lipid profile abnormalities, except lipoprotein (Lp(a)), were associated with CAD. Antibodies to oxidized low-density lipoprotein was higher in patients with CAD. Fibrinogen levels were higher in CAD, but plasminogen activator inhibitor-1 did not show an association with CAD. In the multiple logistic regression analysis, age, body mass index, very-low-density lipoprotein cholesterol, total to high-density lipoprotein cholesterol ratio, and fibrinogen showed significant independent association with CAD. Several lipid abnormalities were associated with CAD in Asian Indians, but no significant association was seen with Lp(a) levels.

Cosegregation of obesity with familial aggregation of type 2 diabetes mellitus

OBJECTIVE

We have shown that a positive family history of diabetes, and the variables of general and central obesity are independent risk factors for type 2 diabetes in our population. This study was done to evaluate whether a familial predisposition to diabetes resulted in a tendency for adverse anthropometric and haemodynamic profiles in south Indian non-diabetic subjects.

METHODS

The analysis was carried out on 2463 subjects (M: F, 1196: 1267) with normal glucose tolerance (NGT). The study subjects were selected from population surveys for diabetes. Details of age, sex, family history of diabetes, body mass index (b.m.i.), waist-to-hip ratio (WHR) and blood pressure were recorded. Serum cholesterol and triglycerides were estimated.

RESULTS

A positive family history of diabetes was present in 24.7% of our subjects. Mean b.m.i. and percentage of obesity were significantly higher in families with a positive family history (group 2) vs. families with no family history (group 1). Subjects in group 2 had a higher 2-h plasma glucose (p < 0.001) and higher prevalence of hypertension (chi2 = 6.91, p = 0.0086). Factor analysis with principle components analysis (PCA) showed that a family history of diabetes clustered with WHR in men, and with b.m.i. and WHR in women. The b.m.i. formed a different domain with blood pressure in both sexes. WHR and b.m.i. clustered with cholesterol and triglycerides in another domain.

CONCLUSIONS

In this population, general and central obesity are associated with a family history of diabetes. A family history of diabetes may increase the risk of hypertension and hyperlipidaemia indirectly through its connection with b.m.i.

Postprandial hypertriglyceridaemia in treated type 2 diabetic subjects --the role of dietary components

Postprandial hyperlipidaemia is a risk factor for cardiovascular diseases (CVD). This study was done (a) to evaluate whether postprandial hypertriglyceridaemia was common in Indian type 2 diabetic patients on treatment and (b) to see whether the high carbohydrate content of the diet was a cause of the lipid abnormality. Two hundred type 2 diabetic subjects (M:F, 137:63; mean age 51.6+/-10.2 years, mean BMI 25.5+/-3.1 kg/m(2)) with diabetes duration of 7.6+/-5.6 years were studied. Fasting and 2 h post prandial responses of plasma glucose and triglycerides (TG) were measured using a breakfast meal, usually consumed by the patient with the intake of usual hypoglycaemic drugs. Patients with a post prandial TG value greater than 15% of the corresponding fasting TG value were designated as group 2 and the remaining subjects as group 1. Dietary composition of the breakfast were calculated. Among the 200 subjects, 52 (26%) had post prandial TG higher than the fasting values. This was seen in patients who were consuming lower percentage of carbohydrates and higher percentage of fats than prescribed. Therefore the postprandial rise in TG was probably due to the high fat content of the diet and due to a lower insulin sensitivity. This study highlights the facts that postprandial hypertriglyceridaemia is seen only in a small proportion of the treated patients and the high carbohydrate diet does not produce hypertriglyceridaemia, either in the fasting or post prandial state. The minority who show an increased TG value at 2 h have been taking lower carbohydrate with higher fat content in the meal. This could have produced a lower insulin sensitivity in these patients.

Vascular complications in young Asian Indian patients with type 1 diabetes mellitus

To determine the prevalence of micro vascular and macro vascular complications in Asian Indian Type 1 diabetic subjects. There has been no major report on the prevalence of vascular complications in Type 1 diabetic patients in India. This study was done in Type 1 diabetic patients, aged < or =20 years at diagnosis of diabetes (n=617, M:F 322:295) with a minimum of 3 year follow-up. Standard diagnostic methodologies were used to test for micro vascular and macro vascular complications of diabetes. Retinopathy was detected in 13. 4% (background diabetic retinopathy 11.2%, proliferative diabetic retinopathy 1.9%, preproliferative 0.31%, maculopathy was seen in 13.3% of retinopathy cases), nephropathy in 7.1%, sensory neuropathy in 3.0%, ischaemic heart disease in 0.5% and peripheral vascular disease in 0.5% of the study subjects. Duration of diabetes showed positive association with retinopathy, nephropathy and neuropathy. Average glycosylated haemoglobin values, at follow up showed an association with retinopathy. Although the glycaemic control was suboptimal in the study group, prevalences of all complications, especially macro vascular complications were lower in Type 1 diabetic patients in this ethnic group, in comparison with the European or American counterparts.

Insulin resistance alone does not explain the clustering of cardiovascular risk factors in southern India

AIMS

To determine whether insulin resistance (IR calculated using the HOMA model) has a dominant role in the clustering of cardiovascular risk factors in the Asian Indian population.

METHODS

A total of 654 non-diabetic subjects aged > or =40 years (male 396: female 258) were selected from a population survey. They had estimates of fasting and 2 h plasma glucose, insulin levels, body mass index (BMI), waist-to-hip ratio (WHR) and blood pressure. Factor analysis was carried out using the principle components analysis (PCA) with varimax orthogonal rotation of continuously distributed variables, considered to represent the components of insulin resistance syndrome including the calculated IR.

RESULTS

There were three major clusters of cardiovascular disease (CVD) risk variables in men and four clusters in women. Insulin resistance, 2 h plasma glucose, insulin and obesity aggregated as the major domain. Insulin resistance was not linked with hypertension. BMI was a common link for all the three factors in men, and for three of the four in women.

CONCLUSIONS

Insulin resistance is not the only underlying factor for the clustering of CVD risk factors in south Indians. These findings are consistent with the presence of several distinct physiological domains, as shown in other ethnic groups.

Limitations of glycosylated haemoglobin as an index of glucose intolerance

This study was conducted (a) to establish a normal cut-off value for glycosylated haemoglobin measured as HbA1c in South Indian subjects, and (b) to evaluate its usefulness in demarcating different categories of glucose intolerance. HbA1c measurement was carried out in 1261 cases with no known history of diabetes, while being tested by oral glucose tolerance test (M:F 850:411, mean age 40+/-12 years). An immunoturbidimetric procedure for HbA1c assay (Tina-Quant, Boehringer Mannheim, Germany) was used. The specificity and sensitivity of HbA1c in demarcating normal glucose tolerance (NGT) from abnormal tolerance were calculated using the ROC procedure. By the ROC analysis, a cut-off value of HbA1c > or = 6.0% gave a sensitivity of 88.5% and specificity of 62.8% using the WHO criteria (2-h plasma glucose > or = 200 mg/dl). Using the ADA criterion (fasting plasma glucose > 125 mg/dl) the sensitivity and specificity for the same cut-off value were 85.2 and 61.2%. In NGT, only a small percentage of the variance in HbA1c was explained by the fasting plasma glucose (FPG) values. The overall correlation coefficient between the fasting plasma glucose and HbA1c was r = 0.8, r2 = 0.64 and, in the case of 2-h post glucose, r = 0.82, r2 = 0.67. This showed that more than 35% of the variations in HbA1c were not explained by the plasma glucose values. The study showed that HbA1c values of > or = 6.0% gave a reasonably high sensitivity and specificity for diagnosis using the WHO or ADA criteria. However, nearly 35% of the variations in HbA1c were not explained by the variations in plasma glucose. Wide inter-individual variations even in the normoglycaemic range make the test unsuitable for diagnostic purpose.

Difference in body fat percentage does not explain the gender dimorphism in leptin in Asian Indians

OBJECTIVE

Leptin is a hormone probably having regulatory function on energy intake and metabolic activities in humans. The study was done: (a) To determine the relation of leptin with the body fat% in Indians, (b) To see whether the differences in body fat accounted for the gender differences in the concentration of leptin and (c) to look for the effect of diabetes on the levels of leptin.

METHODS

Glucose tolerance was determined by oral glucose tolerance test (GTT) in 87 subjects with no known history of diabetes. Leptin was estimated by radio immuno assay. Age, height, weight, waist and hip circumferences were noted. Body mass index (BMI, weight kg/height m2) and waist:hip ratio (WHR) were calculated. The body fat % was estimated by bioelectrical impedance analysis.

RESULTS

Leptin correlated with log fat % and BMI, body weight and waist circumference in different categories of glucose tolerance (Pearson's correlation test). Leptin values were higher in women than in men even after correcting for the body fat % indicating that the gender dimorphism was not explained by the higher fat % in women. The geometric mean of leptin concentration in men was 3.6 ng/ml and in women 10.9 ng/ml (P < 0.0001). Leptin level were not influenced by the status of glucose tolerance. Gender showed a significant effect on leptin concentration (F = 11.0, df = 1.39, P = 0.002) after adjusting for the effect of covariates i.e. percentage of fat (log), BMI, age, WHR and 2 h plasma glucose by ANCOVA. None of the covariates except BMI (P < 0.0001) showed significant correlation with leptin. The total variance explained was 68.4%.

CONCLUSION

We conclude that (1) Plasma leptin is strongly correlated to the body fat content (2) the gender dimorphism of leptin is not explained by the differences in fat percentage and (3) hyperglycemia does not influence plasma leptin levels.

Prevalence of vascular complications and their risk factors in type 2 diabetes

OBJECTIVE

a) To determine the prevalence of microvascular and macrovascular complications in Type 2 diabetes in India and b) to identify the major factors for the complications.

METHODS

A study was done in 3010 subjects (M:F 1892:1118, Mean age 52 +/- 9.7 years) attending a diabetic clinic. The study sample resembled the population sample in anthropometry, age and socioeconomic factors. All patients had undergone the tests for retinopathy, nephropathy, neuropathy, peripheral vascular disease (PVD) and cardiovascular disease by ECG.

RESULTS

Retinopathy was diagnosed in 23.7% (background retinopathy in 20.0% and proliferative in 3.7%), proteinuria was present in 19.7% and persistant proteinuria of > or = 500 mg/dl was seen in 5.5% of them, CHD was present in 11.4% and PVD was present in 4.0%. Of the total 119 cases with PVD, 18 had gangrene and 21 had undergone amputations. Peripheral neuropathy was present in 27.5%. Cerebrovascular accidents were reported in 26 cases (0.9%). Hypertension was present in 38% of the cases. Multiple logistic regression analyses showed that age had a significant association with retinopathy, neuropathy, CHD and PVD. Duration of diabetes had significant association with the complications other than CHD. Higher HbA1 increased the risk of retinopathy, neuropathy and nephropathy. Hypertension was associated with the complications except PVD and neuropathy. The strongest association was between hypertension and nephropathy.

CONCLUSION

The study highlights the high prevalence of vascular complications in Type 2 diabetes in India. Retinopathy and neuropathy were the commonest complications of diabetes.

Insulin secretion and action in different stages of glucose tolerance in Asian Indians

AIMS

To evaluate the sequence of changes in insulin secretion and action in different stages of glucose tolerance and the effect of obesity on insulin profile in South Indian adults. Blood samples from 260 consecutive cases with no known history of diabetes were collected. Plasma insulin levels were measured during a 75-g oral glucose tolerance test. Insulin resistance (IR) was calculated, using the homeostasis model assessment (HOMA). An index of insulin secretion was derived as the ratio of incremental insulin at 30 min divided by 30 minute plasma glucose (delta I/G).

RESULTS

Normoglycaemia was present in 164, impaired glucose tolerance (IGT) in 60 and diabetes in 36 subjects. Fasting and 2 h insulin secretion showed bell shaped curves with increasing plasma glucose. The peak values corresponded to the cut-off values used for the diagnosis of clinical diabetes. IR was higher in obese than in nonobese, nondiabetic subjects but the effect of obesity on IR was not found in subjects with diabetes. IGT was associated with higher IR, but not with evidence of a beta-cell defect.

CONCLUSIONS

Evaluation of insulin resistance and beta-cell function in different stages of glucose tolerance indicate that insulin resistance is manifested in the early stage of glucose intolerance in South Indians, i.e. IGT. A beta-cell defect was mostly found in people with diabetes. The beta-cell defect is more common in diabetes among the nonobese.

Effects of genetic predisposition on proinsulin responses in Asian Indians

This study was done in adult offspring of two diabetic (NIDDM) parents (ODP) to look for changes in specific insulin (insulin) and proinsulin responses due to strong familial background and also in different states of glucose intolerance. Equal numbers (20 in each group) of ODP with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and diabetes (DM) were chosen. Twenty, age and BMI matched healthy controls, without family history of diabetes, were also studied for comparison. Plasma specific insulin and proinsulin were measured by radioimmunoassays in fasting and 120' plasma samples collected during the GTT. Proinsulin to insulin ratio were calculated. Insulin resistance (IR-HOMA) was calculated. In NGT, fasting proinsulin-insulin ratio was significantly higher than the control value (P = 0.023). Insulin values at 120' was higher than control values, though it did not reach statistical significance. Proinsulin at 120' was higher than controls (P = 0.016). In IGT, the fasting proinsulin to insulin ratio, the 120' proinsulin and insulin values were higher than controls (P = 0.048, 0.0013 and 0.0001, respectively). Fasting proinsulin-insulin ratio in IGT was similar to the value in NGT. In diabetic subjects proinsulin concentrations were significantly higher than controls at fasting (P = 0.0004), and 120' (P = 0.0007). The fasting values were higher compared to NGT also (P = 0.037). Proinsulin-insulin ratios were higher than the values in controls (P = 0.0008), IGT (P = 0.047) and NGT (P = 0.05). Diabetic subjects had higher fasting insulin values compared to the control values although between the groups no statistical significance was found (P = 0.22 by Kruscall Wallis test). At 120' both insulin and proinsulin values increased from NGT to IGT, but with development of diabetes a reduction was seen in the responses. Insulin resistance (IR-HOMA) increased steadily from NGT to diabetes. The difference between NGT and controls in IR was not statistically significant. This study of Asian Indian offspring of diabetic parents has shown that genetic predisposition to diabetes resulted in increased proinsulin to insulin ratio at the fasting state. Absolute hyperproinsulinaemia occurred only with development of diabetes.

Clustering of cardiovascular risk factors in urban Asian Indians

OBJECTIVE

To study the prevalence of cardiovascular risk factors in native urban Asian Indians and to look for the occurrence of clustering of these factors.

RESEARCH DESIGN AND METHODS

The study included 953 subjects (532 men and 421 women), aged > or = 40 years, selected from a population survey for diabetes, which was conducted in 1994 in Madras, Tamil Nadu, India. Measurements of anthropometry, blood pressure, plasma lipid profile, glucose tolerance, plasma insulin response, and electrocardiogram were made. Based on the normal ranges derived from the population study, abnormalities in anthropometric values, plasma lipids, and insulin values were determined. Age-adjusted prevalences of the abnormalities were calculated using data from a 1991 urban census in Madras. The expected prevalences of the abnormalities in isolation and in combinations were calculated and compared with the corresponding observed figures.

RESULTS

The prevalences of risk factors were in the order of central adiposity > dyslipidemia > hyperinsulinemia (2-h) > glucose intolerance > obesity > hypertension. The age-adjusted prevalence of coronary heart disease (CHD) was 3.9% (3.5% in men and 4.5% in women, NS), and T wave inversion was seen in an additional 10.3%. Isolated prevalences of all factors, except hypertension, were in lower frequency than expected. Combinations of each risk factor with one or two more risk factors occurred more frequently (1.3-4 times) than expected by chance. Impaired glucose tolerance and dyslipidemia showed association with hyperinsulinemia, whereas hypertension did not show such an association.

CONCLUSIONS

Clustering of the cardiovascular risk factors or the components of insulin resistance syndrome occurs in the native Asian Indian population. This finding under-scores the need for preventive aspects of metabolic disorders and CHD.

Plasma leptin is not associated with insulin resistance and proinsulin in non-diabetic South Asian Indians

In an earlier study, we observed only a weak association between plasma insulin (non-specific assay) and leptin in South Asian Indians. This was in contrast to the observations in many other ethnic groups. With the availability of measurements of specific insulin (SI) and proinsulin (PI) in the same study group, we have reanalysed the data to look for possible correlation of leptin with proinsulin and with insulin resistance calculated from the fasting values of specific insulin and glucose using the HOMA model. Subjects with normoglycaemia (n = 117) and impaired glucose tolerance (n = 27, WHO criteria) were included in the analysis. Leptin values were higher in women. Multiple linear regression analysis showed that the variations in leptin concentrations in men were associated with BMI, WHR, and 2 h SI values (R2 = 56.2%) while fasting SI and proinsulin concentrations had no significant association. In women BMI and age showed a significant association with serum leptin values (R2 = 40.1%). Univariate and multivariate analyses using insulin resistance as the dependent variable showed that it had no association with leptin in both genders. Leptin had no correlation with proinsulin also. This study confirmed that in Asian Indians the association between plasma leptin and insulin concentrations is weak and that leptin has no influence on insulin resistance. Proinsulin and leptin are also not correlated in this population. Insulin resistance shows correlation with the beta-cell function both in men and women.

Specific insulin and proinsulin concentrations in nondiabetic South Indians

The study was performed to determine plasma levels of proinsulin (PI) and specific insulin (SI) in normoglycemic (NGT) Asian Indians and to assess the effect of obesity and impaired glucose tolerance (IGT) on these concentrations. Blood samples from 151 adult nondiabetic South Indian subjects were collected during an epidemiological survey of diabetes. Plasma SI and PI levels were measured in fasting and 30-minute and 120-minute samples of a glucose tolerance test (World Health Organization criteria) using monospecific antibodies. The total insulin (TI) level was also measured by the nonspecific assay. The molar ratio of PI to SI (PI/SI) was calculated. Correlations of the peptides with anthropometry, serum lipids, and blood pressure (BP) were studied by univariate and multivariate analyses. Comparisons were also made in NGT versus IGT groups. As expected, TI values were higher than SI values, but the patterns of response were similar for both. SI and PI responses in NGT were similar to the values found in Mexican-Americans who had a higher body mass index (BMI). Asian Indians were thus found to have a high SI response despite a low BMI. Obesity and IGT produced an increased response of both PI and SI, with normal PI/SI ratios thus showing an absence of hyperproinsulinemia in either condition. Fasting PI showed a strong association with serum triglycerides, and proinsulin at 120 minutes was associated with cholesterol. None of the peptides showed a correlation with BP. Using specific assays for insulin and PI, it is shown that Asian Indians with NGT have a hyperinsulinemic response despite a low BMI. Obesity and mild hyperglycemia in IGT produce a simultaneous increase in PI and SI with no alteration in the PI/SI ratio.

Study of genetic prediabetic south Indian subjects. Importance of hyperinsulinemia and beta-cell dysfunction

OBJECTIVE

To study 1) whether abdominal adiposity was present in adult offspring of two NIDDM parents, 2) whether abdominal adiposity was associated with the development of glucose intolerance, and 3) the association of pancreatic beta-cell function with impaired glucose tolerance (IGT) and NIDDM in these groups.

RESEARCH DESIGN AND METHODS

One hundred offspring whose parents both had NIDDM were studied (60 men, 40 women, mean age 34 +/- 6.9 years, BMI 27.4 +/- 4.1 kg/m2). None had a history of glucose intolerance. Nondiabetic control subjects with no family history of diabetes were also studied for comparison (21 men, 19 women, age 36 +/- 10.3 years, BMI 26 +/- 3.7 kg/m2). A standard oral glucose tolerance test was done for all, and plasma glucose, C-peptide, and insulin responses were measured. Abdominal fat measurements at L4-L5 were made using a computed axial tomography scan. Subcutaneous fat (SF), visceral fat (VF), and total fat (TF) areas were measured and VF/SF ratio was calculated. An index of insulin secretion (delta I/G) was derived as the ratio of incremental insulin at 30 min divided by 30-min plasma glucose.

RESULTS

IGT was detected in 32 offspring and diabetes in 21 offspring. Diabetic men had a higher TF area than the other groups. SF, VF, and VF/SF ratios were similar in control men and in offspring with normal glucose tolerance (NGT), IGT, or diabetes. Among control subjects, women had significantly lower VF than men. Female offspring had higher VF than the control subjects, but intragroup variations were absent. Fasting insulin and all C-peptide responses were higher in NGT compared with control subjects (P < 0.02). The 2-h insulin and C-peptide responses were higher in IGT subjects (P < 0.005). In diabetic subjects, the insulin-to-glucose ratio, C-peptide-to-glucose ratio, and delta I/G were significantly low compared with all other groups (P < 0.005). Multiple logistic regression analysis showed that the area of insulin response had a positive association and delta I/G had a negative association with diabetes, while age, sex, BMI, waist-to-hip ratio, abdominal fat areas, fasting and 2-h insulin, area of insulin, and the C-peptide measurements did not show independent associations. Two-hour insulin showed a positive association with IGT, while increasing area of insulin showed a negative association.

CONCLUSIONS

Visceral adiposity seemed to precede glucose intolerance only in women, but it had no independent association with IGT or NIDDM. Insulin resistance, indicated by higher plasma insulin response, and insulin secretory defect, indicated by low delta I/G at 30 min, were associated with diabetes. beta-cell defect was not independently associated with IGT. Increased abdominal visceral adiposity does not appear to be a prerequisite for development of IGT or diabetes in Asian Indians with a strong genetic predisposition for diabetes.

Plasma leptin in non-diabetic Asian Indians: association with abdominal adiposity

Plasma leptin concentrations were measured in 144 non-diabetic men and women (age 21-73 years, BMI 14.8-37.7 kg m(-2)), in fasting samples collected during a population survey for diabetes mellitus. Leptin, fasting and 2-h post-glucose load plasma concentrations of glucose and immunoreactive insulin were measured. In a subset of 50 normoglycaemic individuals, subcutaneous fat (SF) and visceral fat (VF) areas at L4-L5 level were also measured by CT. As in other populations, women had significantly higher plasma leptin concentrations than men (p < 0.001) but the values were similar in normal (NGT) and impaired glucose tolerance (IGT). Geometric mean concentrations of leptin in men and women with NGT were 4.8 and 17.7 ng ml(-1), respectively, and the corresponding values in IGT were 6.2 and 19.0 ng ml(-1). Multiple regression analysis in the total group showed that the leptin concentration (log-transformed) was strongly dependent on sex (R2 = 53.4%), BMI (R2 = 17.4%), and to a lesser degree on the 2-h plasma insulin (R2 = 2.4%) and the WHR (R2 = 0.8%). In men, the total abdominal fat showed a strong association with leptin (R2 = 49.3%) and in women the subcutaneous fat area showed a similar effect (R2 = 39.5%). It is likely that subcutaneous and not visceral fat may be a determinant of plasma leptin in Asian Indians, and the correlation between leptin and insulin resistance may be less strong than in other ethnic groups.

Computed axial tomographic scan measurement of abdominal fat distribution and its correlation with anthropometry and insulin secretion in healthy Asian Indians

Asian Indians have high insulin resistance, hyperinsulinemia, a high prevalence of diabetes, and a high waist to hip ratio (WHR), although the rate of obesity is low. WHR and visceral fat (VF) are highly correlated, and both are associated with insulin resistance. This study was performed to determine the normal ranges of abdominal fat distribution (subcutaneous [SF] and VF) in nondiabetic South Indians and also to study its correlations with WHR, plasma insulin, and metabolic profiles. Fat areas were measured by computed axial tomographic scan at the L4 to L5 level. Mean areas of SF and VF in men and women in this study were similar to the values in white populations. Women had significantly less VF than men. Gender differences were observed in the contribution of fat areas to anthropometric, hormonal, and metabolic variables. In general, in men, total fat (TF) area showed significant independent correlation with body mass index (BMI), WHR, and total cholesterol, and VF correlated with insulin secretion. In women, TF and BMI were correlated and SF showed a correlation with total cholesterol. Insulin secretion in women did not show a correlation with fat areas.