Evidence that single nucleotide polymorphism in the uncoupling protein 3 (UCP3) gene influences fat distribution in women of European and Asian origin

AIMS/HYPOTHESIS

Uncoupling proteins are mitochondrial transmembrane carriers implicated in the regulation of energy balance. Dysfunction of UCP3 (the predominant uncoupling protein in skeletal muscle) might therefore be expected to reduce thermogenic capacity, alter energy homeostasis and influence predisposition to obesity and Type II (non-insulin-dependent) diabetes mellitus. A variant in the putative promoter region of UCP3 (-55 c-->t) has recently been identified, and an association with obesity reported in French subjects. Our aim was to study the pathophysiological role of this variant in diabetes-related and obesity-related traits using two distinct ethnic populations.

METHODS

The -55 c-->t variant was genotyped in 85 South Indian and 150 European parent-offspring trios ascertained through Type II diabetic probands and in 455 South Indian subjects initially recruited to an urban survey into the prevalence of diabetes.

RESULTS

In South Indian and European parent-offspring trios there was no preferential transmission of either allele at the -55 c-->t polymorphism to diabetic offspring (South Indians, p = 0.60; Europeans, p = 0.15). When family members were analysed for intermediate traits, the t-allele was associated with increased waist-to-hip ratio but only in females (South Indian mothers p = 0.036, daughters p = 0.032: European mothers p = 0.037, daughters p = 0.14). These findings were replicated in South Indian females from the population-based survey (p = 0.039).

CONCLUSION/INTERPRETATION

The consistent association between the t-allele at this locus and increased waist-to-hip ratio in women from three separate data sets indicates that variation at this polymorphism (or another locus with which it is in linkage disequilibrium) influences fat distribution but that this effect is restricted to females.

Cost burden to diabetic patients with foot complications--a study from southern India

AIM

To study the economic burden of management of diabetes in patients with foot complications, as a large number of them suffer from foot complications of varying severity. This study relates to direct cost to diabetic patients with foot complications.

MATERIAL AND METHODS

An illustrative sample of 270 Type 2 diabetic subjects, 164 without foot complications (Control group, Group 1) and 106 with foot complications (Group 2) were studied. They were available for the study during a six month period from January to June 1998. Group 2 had two sub-groups, i.e., those who needed out-patient (OP) treatment only (n = 23) and those who needed treatment in the hospital (HP) (n = 83). The study subjects were interviewed personally by the educator to collect demographic data and treatment expenditure.

RESULTS

Total median expenditure incurred by the diabetic subjects without foot complications (Group 1) was Rs. 4373/- and by those with foot complications (Group 2) was Rs. 15,450/-. Patients who required hospitalised treatment incurred higher expenses than the OP patients, towards doctor's fees and hospitalisation (P < 0.0001). The percent of total income spent by the HP patients was higher than by the OP patients (P < 0.02).

CONCLUSIONS

Diabetic subjects with foot problems incur very heavy expenditure in the treatment process. Most of the direct costs of diabetes treatment results from its complications. The hospitalisation costs for the complications of diabetes are particularly heavy. This underscores the need to reduce complications and also their economic burden.

Familial aggregation of central obesity in Southern Indians

BACKGROUND

High prevalence of diabetes in South Asians is associated with a pronounced tendency to abdominal obesity. This intermediate quantitative trait may be more amenable than type 2 diabetes to genetic linkage studies.

OBJECTIVES

To derive a measure of central obesity independent of total adiposity and adjusted for factors under environmental influence, and to estimate the genetic contribution to familial aggregation of this trait.

SUBJECTS AND METHODS

A total of 1,295 individuals from 300 families were studied in a community-based cross-sectional study in Chennai, India. Central fat was measured using sagittal abdominal diameter, and adjusted for age, BMI and body fat percentage measured by impedance. Intra-sibship correlations were calculated for adjusted sagittal abdominal diameter and a comparison variable, adjusted body fat percentage.

RESULTS

Among individuals free of diabetes, intra-sibship correlations were 0.48 for adjusted sagittal abdominal diameter and 0.14 for adjusted body fat percentage.

CONCLUSIONS

Even after adjustment for possible assortative mating, these results are consistent with a heritability exceeding 90% for a trait defined as abdominal fat accumulation adjusted for total adiposity, sex and age. Linkage studies of abdominal obesity that map one or more of the genes underlying this high heritability are therefore a possible route to identifying genes for type 2 diabetes in South Asians.

Phosphorylation of serine 51 in initiation factor 2 alpha (eIF2 alpha) promotes complex formation between eIF2 alpha(P) and eIF2B and causes inhibition in the guanine nucleotide exchange activity of eIF2B

Phosphorylation of serine 51 residue on the alpha-subunit of eukaryotic initiation factor 2 (eIF2alpha) inhibits the guanine nucleotide exchange (GNE) activity of eIF2B, presumably, by forming a tight complex with eIF2B. Inhibition of the GNE activity of eIF2B leads to impairment in eIF2 recycling and protein synthesis. We have partially purified the wild-type (wt) and mutants of eIF2alpha in which the serine 51 residue was replaced with alanine (51A mutant) or aspartic acid (51D mutant) in the baculovirus system. Analysis of these mutants has provided novel insight into the role of 51 serine in the interaction between eIF2 and eIF2B. Neither mutant was phosphorylated in vitro. Both mutants decreased eIF2alpha phosphorylation occurring in hemin and poly(IC)-treated reticulocyte lysates due to the activation of double-stranded RNA-dependent protein kinase (PKR). However, addition of 51D, but not 51A mutant eIF2alpha protein promoted inhibition of the GNE activity of eIF2B in hemin-supplemented rabbit reticulocyte lysates in which relatively little or no endogenous eIF2alpha phosphorylation occurred. The 51D mutant enhanced the inhibition in GNE activity of eIF2B that occurred in hemin and poly(IC)-treated reticulocyte lysates where PKR is active. Our results show that the increased interaction between eIF2 and eIF2B protein, occurring in reticulocyte lysates due to increased eIF2alpha phosphorylation, is decreased significantly by the addition of mutant 51A protein but not 51D. Consistent with the idea that mutant 51D protein behaves like a phosphorylated eIF2alpha, addition of this partially purified recombinant subunit, but not 51A or wt eIF2alpha, increases the interaction between eIF2 and 2B proteins in actively translating hemin-supplemented lysates. These findings support the idea that phosphorylation of the serine 51 residue in eIF2alpha promotes complex formation between eIF2alpha(P) and eIF2B and thereby inhibits the GNE activity of eIF2B.

Protease activation during surgical stress in the rat small intestine

BACKGROUND

Surgical stress affects intestinal permeability and our earlier study using a rat model indicated that oxidative stress plays an important role in this process. Proteases are important mediators of cellular damage and are known to be activated in oxidative stress. This study looked at protease activity in enterocytes after surgical stress.

METHODS

Surgical stress was induced by opening the abdominal wall and handling the intestine as done during laparotomy, in normal and xanthine oxidase-deficient rats. Enterocytes at various stages of differentiation were isolated and protease activity and protection offered by xanthine oxidase inhibitors were determined. Mitochondria and cytosol were prepared from total isolated enterocytes at different periods after surgical stress and protease activation was studied.

RESULTS

Surgical stress induced activation of proteases in both the villus and crypt cells. Protease activation is seen in both mitochondria and cytosol, and similar to the other alterations in mucosal cells, protease activation was maximum 60 min after stress, returning to normal by 24 h. Thiol compounds modulate protease activity in both mitochondria and cytosol and the activation is not seen in xanthine oxidase-deficient animals.

CONCLUSIONS

Surgical stress induces activation of proteases in villus and crypt cells of the small intestine. Both mitochondrial and cytosolic proteases are activated and free radicals generated by xanthine oxidase may mediate protease activation after surgical stress in the intestine.

Family association studies of markers on chromosome 2q and Type 1 diabetes in subjects from South India

BACKGROUND

Several Type 1 diabetes susceptibility loci have been located to chromosome 2q12-21. However, results have not always been consistent and this may reflect study design and the population analysed. We have used a family-based design to look for an association between Type 1 diabetes and markers located to 2q12-21.

METHODS

Ninety-one South Indian families consisting of subjects with Type 1 diabetes and their parents were genotyped for eight polymorphic markers localised to 2q12-21, which includes the interleukin-1 gene cluster. Radiation hybrid mapping was used to localise the map position of D2S308 and D2S363 on 2q12-21. The extended transmission disequilibrium test was used for statistical analysis.

RESULTS

No associations were found between Type 1 diabetes and markers located in and around the interleukin-1 gene cluster or the interleukin-1 Type 1 receptor. In contrast, a suggestive association was found between Type 1 diabetes and two closely-linked markers telomeric of the interleukin-1 gene cluster (D2S308 and D2S363, separated by 3.3 cR) (p=0.004 and p=0.002, respectively).

CONCLUSION

This preliminary study suggests that a locus close to D2S308 and D2S363 is involved in the aetiology of Type 1 diabetes in the South Indian population.

High prevalence and early onset of cardiac autonomic neuropathy among South Indian type 2 diabetic patients with nephropathy

OBJECTIVE

This study was conducted to assess the adverse effects of diabetic nephropathy on cardiovascular autonomic neuropathy (CAN) in South Indian Type 2 diabetic patients.

METHODS

Comparison was made between Type 2 diabetic patients with nephropathy (group 1, n=25), Type 2 diabetic patients without nephropathy (group 2, n=25) and non-diabetic, non-hypertensive control subjects (n=20). All had a detailed clinical and biochemical work-up and cardiac assessment by ECG. Cardiac dysautonomia was assessed by a battery of five non-invasive autonomic function tests (ANF) as recommended by Ewing and Clarke [D.J. Ewing, B.F. Clarke, Diagnosis and Management of autonomic neuropathy. Br. Med. J. 285 (1982) 916-918].

RESULTS

Group 1 patients showed a higher percentage of abnormal CAN function and a more severe form of CAN compared with patients in group 2. Group 1 patients showed early development of the abnormalities. They also had a higher prevalence of peripheral neuropathy compared with the patients without nephropathy.

CONCLUSIONS

The present study showed that the presence of nephropathy was associated with the risk of cardiac autonomic neuropathy in Type 2 diabetic patients and it probably had an earlier onset also in them.

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.

Expenditure on health care incurred by diabetic subjects in a developing country--a study from southern India

The objective of the study was to estimate the direct costs of diabetes care to patients attending secondary care facilities in Madras, India. A total of 596 subjects were studied, at the Private Hospital for Diabetes Mellitus (PHD) (n = 422), and at the Government General Hospital (GGH) (n = 174). A simple interview schedule enabled a face to face interaction with the patients by the research investigator which elicited a frank and true response. The validity of the data collected was established by independent scrutiny of financial records in a sub sample. Payment bills for expenses of 140 subjects chosen on a random basis from the total sample of 422 PHD patients were compared with the costs reported by the subjects. There were no statistically significant differences both in the inpatient and the outpatient cases between the reported cost and actual cost. Median bill value (total costs)=Rs.1010 (range 195-16700) reported value=880 (110-20355) Z = -0.97, P = 0.33 and, for outpatients, median bill value=Rs.800 (195-4560) reported value=Rs. 740 (110-6320) Z = -1.56, P = 0.12. For inpatients, median bill value = Rs. 4235 (1289-16700) reported value=Rs.5459 (1285-20355), Z = -1.27, P5 years duration of diabetes spent more than those who had <5 years of duration; Rs.5570 (360-75200) and Rs.3220, (460-25600), respectively. All differences between these sub-groups were statistically significant. Within the ambit of economic aspects of the population in a developing country, the direct cost on diabetes health care is very high for many people.

Clinical profile of diabetic foot infections in south India--a retrospective study

AIMS

The aim of the study was to determine the profile of diabetes foot infections in south Indian diabetic subjects. The causative factors for delayed wound healing and the recurrence of infection were also studied.

METHODS

During a period of 6 months, 374 patients who had undergone some surgical procedure for foot infection were available for follow-up (M:F 227:147, mean age 54.9 +/- 9.4 years, diabetes duration 10.9 +/- 7.7 years). All of them had records of clinical and treatment details, laboratory data including biothesiometry, Doppler tests and electrocardiogram (ECG) records. Foot ulcers were classified according to Wagner's classification.

RESULTS

Majority of the patients had grade II and III ulcers (50% and 26.5%, respectively), grade IV was seen in another 21.9%. The median healing time was 44 days. Recurrence of infection which occurred in 53% was more common in patients with neuropathy and peripheral vascular disease (PVD).

CONCLUSIONS

Recurrence of foot infection was common among south Indian Type 2 diabetic subjects and was related to the presence of PVD and neuropathy. There is also a need for improvement in footwear and foot care education.

Attenuation of intestinal ischemia/reperfusion injury with sodium nitroprusside: studies on mitochondrial function and lipid changes

Reactive oxygen species have been implicated in cellular injury during ischemia/reperfusion (I/R). Mitochondria are one of the main targets of oxygen free radicals and damage to this organelle leads to cell death. Reports suggest that nitric oxide (NO) may offer protection from damage during I/R. This study has looked at the functional changes and lipid alteration to mitochondria during intestinal I/R and the protection offered by NO. It was observed that I/R of the intestine is associated with functional alterations in the mitochondria as suggested by MTT reduction, respiratory control ratio and mitochondrial swelling. Mitochondrial lipid changes suggestive of activation of phospholipase A(2) and phospholipase D were also seen after (I/R) mediated injury. These changes were prevented by the simultaneous presence of a NO donor in the lumen of the intestine. These studies have suggested that structural and functional alterations of mitochondria are prominent features of I/R injury to the intestine which can be ameliorated by NO.

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.

Apoptosis in the intestinal epithelium: its relevance in normal and pathophysiological conditions

Apoptosis is now recognized as an important process responsible for maintenance of the cellular balance between proliferation and death. Apoptosis is distinct from necrosis in that it is a programmed form of cell death and occurs without any accompanying inflammation. This form of cell death can be induced by a wide range of cellular signals, which leads to activation of cell death machinery within the cell and is characterized by distinct morphological changes. Apoptosis is especially relevant in the gastrointestinal tract, as the mammalian intestinal mucosa undergoes a process of continual cell turnover that is essential for maintenance of normal function. Cell proliferation is confined to the crypts, while differentiation occurs during a rapid, orderly migration up to the villus. The differentiated enterocytes, which make up the majority of the cells, then undergo a process of programmed cell death (apoptosis). Although apoptosis is essential for the maintenance of normal gut epithelial function, dysregulated apoptosis is seen in a number of pathological conditions in the gastrointestinal tract. The cellular mechanisms regulating this tightly regimented process have not been clearly defined and this topic represents an area of active investigation as delineation of this process will lead to a better understanding of normal gut mucosal growth.

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.

Scintigraphic evaluation of colonic transit in two patients with idiopathic chronic constipation

Bowel transit in two women with protracted constipation was evaluated after oral administration of In-111 DTPA in water. Serial abdominal images were obtained for as long as 96 hours to assess transit through the stomach, small bowel, and colon. In both patients, large bowel transit was delayed. A pattern of colonic inertia was observed in one patient, whereas retention in the distal colon was seen in the other patient. Both patients underwent total colectomy with marked symptomatic relief. Colonic transit studies of these patients are presented, and the literature is reviewed.

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.

Patients' adherence to diabetes treatment

OBJECTIVES

a) To evaluate the patients' adherence to the treatment prescriptions and b) to analyse the reasons for non adherence.

METHODS

A random sample of 386--type 2 diabetic subjects (M:F 223:163) were studied. Each subject was personally interviewed using a computerised proforma. The mean age of the study group was 52 +/- 10 years and 53% were treated with oral hypolycenic agent (OHA) and the rest with a combination of insulin and OHA. The mean duration of diabetes was 11.0 +/- 6.9 yrs. The overall adherence to the treatment regimen, diet and drug prescriptions and also regularity of home glucose monitoring by blood or urine tests were assessed.

RESULTS

It was noted that only 25% of the study group were adhering to the treatment regularly. Dietary prescriptions were followed regularly only by thirty seven percent. Home glucose monitoring was being done only by twenty three percent. Non adherence was not related either to the age or duration of diabetes. Non adherence was more in the lower socio-economic group and was inversely related to the educational status. It was noted that approximately 20% of the subjects had an indifferent attitude to the advice given.

CONCLUSIONS

The results showed that the rate of non adherence of treatment prescriptions was high. It stresses the need for constant motivation and one to one level education at frequent intervals to ensure better compliance to the treatment.

Need for education on footcare in diabetic patients in India

OBJECTIVES

The patient himself plays the crucial role in the prevention of diabetic foot disease and therefore education on foot care is important. In this study, we have evaluated the knowledge of the diabetic subjects regarding the foot problems and the care of feet in order to identify areas that require stress in the education programme.

PATIENTS AND METHODS

Two hundred and fifty, consecutive cases of Type 2 diabetes (M:F, 176:74, age 57.2 +/- 9.7 yrs, duration 12.9 +/- 7.9 yrs) were selected for this study from the out-patient department of our hospital. A questionnaire was filled up for each patient by personal interview. The total score was 100 and a score of < 50 was considered as a low score for foot care knowledge.

RESULTS

A score of < 50 was obtained in 67.2%. Low score was more common in women (78.5%) than in men (62.5%) (chi 2 = 5.26, P = 0.022). Low scores (< 50) were more common among those with lower level of formal education (chi 2 = 70.0, P < 0.0001), there were more women with low educational status. Significant foot problems like gangrene, foot ulcers were present in 27.2% and low scores were more common among those with these complications (82% vs 62%) (chi 2 = 8.3, P = 0.004). In general the scores on awareness of general foot care principles and basic facts about the foot complications were poor. Most of them (72%) had good knowledge about the right usage of foot wear. There was a trend to have lower scores with poor formal education (chi 2 = 51.1, P < 0.0001) and also with increasing age. There was no correlation between the scores and the number of hospital visits. Multiple linear regression analyses showed that 31.2% of the variations in the scores were explained by the level of education.

CONCLUSIONS

This study underscores the importance of patient education on foot care principles, especially so, considering the magnitude of the problem of diabetes and the lower levels of literacy and poor socio economic status of many patients in this country.

Type 1 diabetes in the offspring does not increase the risk of parental type 2 diabetes in South Indians

OBJECTIVES

(a) To study whether there was an increased prevalence of glucose intolerance in the parents of probands with Type 1 diabetes and (b) to look for any possible link between the glucose intolerance in the parents with HLA-DQB1 alleles transmitted in excess to the Type 1 diabetes offspring. Study Design and Methods From 215 families of South Indian Type 1 diabetes probands, 336 parents (170 fathers, age 30-70 years; 166 mothers, age 23-72 years) were studied by oral glucose tolerance test (GTT). Glucose intolerance in the parents was compared with the population data available. HLA-DQB1 alleles in 170 of the families were studied by the Olerup method (based on sequence specific primers) and the transmission disequilibrium test (TDT) was used to determine the Type 1 diabetes-associated DQB1 alleles.

RESULTS

Among the parents 11.2% had Type 2 diabetes which was similar to the population data of 11.6%. However there was a male predominence among the diabetic parents (chi(2)=7.0, p=0.008), while in the population there was a female predominence. Prevalence of IGT was significantly more among the parents (13.6%) compared with the population data (9.1%) (chi(2)=6.43, p=0.011). Both HLA-DQB1*0201 (p<0.0001) and DQB1*0302 (p=0.0001) were positively associated with Type 1 diabetes in the probands although 21% of the probands possessed neither DQB1*0201 or DQB1*0302. The distribution of glucose tolerance categories in the parents of the probands differed according to the presence of DQB1*0302 (p= 0.035) whilst no such differences existed for DQB1*0201.

CONCLUSIONS

In summary, the presence of Type 1 diabetes in the South Indian offspring does not predict a higher occurrence of Type 2 diabetes in the parents. However, there is an increased occurrence of impaired glucose tolerance (IGT) among the parents. Family based studies demonstrate increased transmission of HLA-DQB1*0201 and HLA-DQB1*0302 with Type 1 diabetes similar to North American and European Caucasian subjects. Furthermore, HLA-DQB1*0302 may be a minor determinant of glucose tolerance in parents of offspring with Type 1 diabetes.

Influence of life style factors in development of diabetes in Indians--scope for primary prevention

OBJECTIVE

The objective of the study was to evaluate the influence of physical activity and stress factors on the development of diabetes mellitus (DM).

METHODS

One hundred and eighty-seven adult subjects (M:F 112:75), registered in the primary prevention of diabetes programme for 2 or more years were studied prospectively. The study was done only in those who had either normal glucose tolerance (NGT) or diabetes at the time of review (tR). At entry (tE), 121 (64.7%) had normal glucose tolerance (NGT) and 66 (34.3%) had impaired glucose tolerance (IGT) by the WHO criteria. Dietary modifications and regular exercise programme were advised. Dietary modifications and regular exercise programme were advised. Study subjects were reviewed during August 1997 to October 1998. At review (TR) none had known history of diabetes. At TR, the status of glucose tolerance was assessed by oral GTT and influence of intervention measures and evaluation of the role of physical and psychological stress on glucose tolerance were assessed by a questionnaire method.

RESULTS

At tR, 100 (53.5%) had NGT, and 87 (46.5%) had developed diabetes (DM). Adherence to exercise and other preventive measures was poor in the DM compared to nondiabetic group (NGT) (P < 0.0012). They showed lower dietary adherence (P = 0.042) and scores on mental stress was higher than in NGT group (P < 0.001). After controlling for age, gender and the initial 2 h plasma glucose, non-adherence to exercise and high scores of psychological stress showed strong association with diabetes.

CONCLUSION

In this study, significant and independent roles of physical inactivity and psychological stress factors are demonstrated in the development of diabetes.

Nitric oxide prevents anoxia-induced apoptosis in colonic HT29 cells

Apoptosis is a critical determinant of tissue mass homeostasis and may play a role in carcinogenesis. The aim of the present study was to investigate anoxia-induced cell death in colon-derived HT29 cells and the effect of nitric oxide on this phenomenon. It was found that HT29 cells subjected to anoxia undergo apoptosis in a time dependent manner, as determined by DNA fragmentation and Hoechst-33258 dye staining. Cytochrome c release from mitochondria to cytosol is a key step in this process and this release precedes DNA fragmentation. NO inhibits anoxia induced apoptosis in these cells by inhibiting the release of cytochrome c and thus may play a role in modulating the apoptotic cell death of colon-derived epithelial cells.

Impacts of urbanisation on the lifestyle and on the prevalence of diabetes in native Asian Indian population

Recent studies from the Asian subcontinent show an increasing prevalence of diabetes. This increase has been attributed to factors related to lifestyle changes related to modernisation. A periurban rural population resembling the rural in their occupation, but with access to certain urban facilities was chosen for this study. The aim of the study was to assess the impact of modernisation on the rising prevalence of diabetes in the native Indians. A total of 1637 adults aged 20 years and above (749 men and 888 women) were tested for diabetes and impaired glucose tolerance (IGT) by 2 h post-glucose challenge. Demographic, anthropometric, dietary and occupational details, were recorded. Dietary habits were similar in all categories of socio-economic strata. In the present study group, the age standardised prevalence of Type 2 diabetes was 5.9%, which was intermediate to that in the urban (11.6%) and rural (2.4%) populations. The prevalence data of the latter two population were available from previous surveys. Prevalence of impaired glucose tolerance (IGT) was high (6.9%) and similar in all three population samples. In the periurban population, a large percentage of subjects were doing only routine household work and had a sedentary life-style. After correcting for the age and BMI, sedentary work and occupation had a significant association with diabetes, suggesting that sedentary lifestyle may be an important determinant for the higher prevalence of diabetes in an urbanising population.

An uncoupling protein 2 gene variant is associated with a raised body mass index but not Type II diabetes

AIMS/HYPOTHESIS

Linkage between markers close to the uncoupling protein 2 and 3 genes (11q13) and resting metabolic rate and a pre-diabetic phenotype have been found. The syntenic region in mouse has been found to be linked to quantitative traits associated with obesity and diabetes. UCP2 and UCP3 could therefore have an important role in body weight regulation and susceptibility to diabetes. We investigated a recently identified variant of the UCP2 gene in exon 8 as a marker for glucose and weight homeostasis.

METHODS

Length variation of the UCP2 exon 8 variant was studied by the polymerase chain reaction and agarose gel electrophoresis. Sequence variants of the UCP3 gene were sought by semi-automated DNA sequencing.

RESULTS

In 453 South Indian subjects, we found an association in women between the UCP2 exon variant and body mass index (p = 0.018). These findings were replicated in a separate group of South Indian subjects (n = 143, p < 0.001) irrespective of sex. Although no association was found between the UCP2 exon 8 variant and overt obesity in British subjects, the UCP2 genotype of obese women (n = 83) correlated with fasting serum leptin concentration (p = 0.006) in the presence of extreme obesity. These observations could not be explained by tight linkage disequilibrium with a coding region variant in the region of the UCP3 gene of biological significance. Lastly, no association was found between UCP2 and Type II (non-insulin-dependent) diabetes using either a family based design (85 families) or case control study (normal glucose tolerance n = 335, impaired glucose tolerance n = 42, Type II diabetes n = 76).

CONCLUSION/INTERPRETATION

We have described a UCP2 gene exon 8 variant that may affect susceptibility to weight gain by influencing regulation of leptin.

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.

Familial aggregation of diabetic kidney disease in Type 2 diabetes in south India

The study was done to assess whether there was a familial aggregation of diabetic kidney disease (DKD) in Type 2 diabetic subjects. The profile of associated complications was also studied. Two groups of diabetic siblings of Type 2 diabetic patients, matched for age, body mass index (BMI) and duration of diabetes mellitus were studied. The siblings also had Type 2 diabetes. Group A comprised of siblings of probands with diabetic nephropathy and retinopathy (n = 30, M:F = 20:10) and Group B were siblings of probands without diabetic nephropathy or microalbuminuria (MAU) (n = 30, M:F = 14:16). Anthropometry, measurement of blood pressure and tests for proteinuria, MAU and retinopathy and ECG and biothesiometry were carried out for all study subjects. Persistent proteinuria was present in 15 (50%) siblings in group A and none in group B. MAU was detected in 26.7% (n = 7) in Group A and 3.3% (n = 1) in Group B (P = 0.057). Thus a total of 22 out of 30 cases in Group A had albuminuria. In Group A, seven (23.3%) had proteinuria and hypertension. Hypertension was present in nine (30.0%) in group A, and in five (16.7%) in group B (NS). Occurrence of retinopathy was found to be significantly higher in group A than in group B (33.3 vs 6.7%, chi2 = 5.1, P = 0.023). Abnormal ECG changes were present in 10% and 6.7% in Group A and Group B, respectively. In Group A, one patient had peripheral vascular disease (PVD) while in Group B none had PVD. A comparison of sib pairs, matched for age, duration of diabetes and the level of metabolic control showed that there was strong familial clustering of diabetic kidney disease in south Indians with Type 2 diabetes. This was independent of the familial clustering of diabetes. Prevalence of other vascular complications were also higher in Group A.

Dietary profile of urban south Indians and its relations with glycaemic status

This study was done to analyse the dietary profile of urban south Indian adults. It was also aimed to study, if the dietary profile influenced the glycaemic and anthropometric data. Dietary details were collected in a representative urban sample of 900 study subjects in the epidemiological survey for diabetes conducted in 1995 in the city of Madras. The details were collected by a 24-h recall method. All the dietary factors were similar in the non-diabetic (NGT) and newly diagnosed diabetic cases, but the values were lower in known diabetic cases due to dietary modifications (P < 0.001 for all compared to NGT and new diabetic cases). For further analysis, known diabetic cases were deleted and the rest were combined as one group. Men consumed higher calories (2066+/-437, range 1028-3662 kcal) than women (1745+/-343, range 870-3260 kcal) (P < 0.01). Older persons consumed lower calories and percentages of the proximate principles in diet were proportionately lower. Higher calorie consumption was due to consumption of higher quantities of food and not any specific dietary factor. BMI, WHR, plasma glucose, serum cholesterol and triglycerides were not significantly influenced by the total calorie consumption. Calorie consumption was higher in persons engaged in strenuous physical activity. Total calories and proportionately the proximate principles of diet were less in the high income group. The similarity in diet in the non-diabetic and the newly diagnosed diabetic persons showed that the development of diabetes was probably not related to changes in dietary habits. Lower consumption of calories and carbohydrates by the known cases of diabetes was due to the dietary modifications introduced in the management of the disease. Lower calorie consumption in women and older people could be related to lower physical activity. This study shows a uniform dietary pattern among the different strata of society with minor variations based on age, gender and physical activity. No difference has been noted in dietary habits of the newly diagnosed diabetic subjects and the non-diabetic adults.

Foetal outcome in gestational diabetes in south Indians

The study was performed to reassess the prevalence of gestational diabetes mellitus (GDM) in south Indians and to study the foetal outcome in women with GDM in comparison with normal pregnancies. In 1036 pregnant women, glucose tolerance was tested with 75-g oral glucose load, in the second or third trimester. Those with 2-h plasma glucose of > or = 200 mg/dl were considered as diabetic (WHO Criteria). Those with 2-h values of 140-199 underwent a 3-h glucose tolerance test (GTT) with 100-g glucose load (O'Sullivan and Mahan criteria). GDM was diagnosed in nine women (0.87%) by this criteria. Foetal outcome in 211 GDM referred to the diabetes centre was compared with the outcome in 853 normal pregnancies. There were no cases of aborted pregnancy among the GDM, while six cases were reported among the normal glucose tolerance (NGT). Still birth and the number of premature babies were higher in GDM. Babies with birth weight > or = 3.5 kg were more among the GDM (P < 0.001). There was no difference in the occurrence of congenital anomalies in the two groups. It was noted that congenital abnormalities in the foetus were more common among those born of mothers with higher plasma glucose (9 versus 1.1%). Multiple linear regression analyses in NGT and GDM showed that the birth weight of the baby was dependent on the plasma glucose and the body mass index of the mothers. The results of the present study show that the prevalence of GDM in urban south India was low, when the NDDG criteria was used. It also indicated that the WHO criteria may be more appropriate as the foetal outcome was determined by even a small rise in maternal plasma glucose. With good metabolic control in GDM, the foetal risks are very much reduced.

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.

Cardio vascular morbidity in proteinuric south Indian NIDDM patients

Proteinuria is a well known risk factor for cardiovascular morbidity. There has been no report on cardiovascular morbidity in Indian NIDDM patients with proteinuria. Hence this study has been undertaken to estimate the prevalence of cardiovascular diseases (CVD) in South Indian NIDDM with proteinuria. We studied two groups of NIDDM patients with diabetes for > or = 5 years: group PR with persistent proteinuria of > 500 mg/day (n = 297) and group NPR with normoalbuminuria (albuminuria < or = 30 micrograms/mg creatinine)(n = 296), who reported for review during the study period. They were matched for age, duration of diabetes and BMI. The prevalence of cardiovascular diseases, namely myocardial infarction, the presence of ischaemic heart disease and the history of coronary bypass surgery were compared in the two groups. The prevalence of hypertension was higher among the PR than the NPR patients (56.5 vs 24.7%, chi 2 = 61.3, P < 0.01). CVD were detected in 39.2% (n = 116) of the PR and 13.2% (n = 39) of the NPR groups. (chi 2 = 54.85, P < 0.001). The risk was thus three-fold higher in the PR group. Univariate analysis showed that in the proteinuric group, the prevalence of complications was higher in association with hypertension (45.8% vs 30.2%, chi 2 = 6.82, P = 0.009). Multiple logistic regression analysis showed that the factors associated with CVD were proteinuria (odds ratio 5.03), age (OR 1.08) and BMI (OR 1.07) while sex, age at onset of diabetes, duration of diabetes, hypertension, smoking, HbA1, serum creatinine, cholesterol and triglycerides did not show independent contribution. The study, highlights the high risk conferred by macroproteinuria in Indian NIDDM patients. This risk is found to be independent of the presence of associated hypertension.

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.

Does the presence of diabetic nephropathy in parents influence the metabolic response in the offspring?

Non-insulin dependent (Type 2) diabetes mellitus (NIDDM) and long-term complications such as nephropathy have a strong genetic predisposition. Insulin resistance is thought to be a pathogenetic factor, predisposing genetically prone individuals to develop the microvascular complications of diabetes. To test these hypotheses, two groups of young individuals were studied: 28 offspring of parents having NIDDM and diabetic nephropathy (group 1) aged 29.5 +/- 6.1 years, BMI 25.2 +/- 4.7 kg m(-2) and 31 offspring of diabetic parents with no history of nephropathy, aged 31.6 +/- 4.1 years and BMI 26.3 +/- 4.9 kg m(-2) (group 2). All underwent a standard oral glucose tolerance test with measurement of serum insulin levels and serum lipid profile. Urine albumin:creatinine ratio (A/C ratio) and blood pressure were also recorded. Diabetes was detected in 2/28 (7.1%) and 3/31 (9.7%) and IGT was detected in 5/28 (25%) and 8/31 (25%) of groups 1 and 2, respectively. These differences were not statistically significant, but were higher than in a group of non-diabetic controls with healthy parents. Comparison of the normoglycaemic subjects (19 and 20 in group 1 and 2, respectively) showed no significant differences between blood pressure readings, fasting and 2 h plasma glucose, and lipid profiles. Plasma insulin values, fasting and 2 h, and the area under the graph were also similar in both groups, indicating an absence of higher insulin response in group 1 in comparison with group 2. These values were also not different from those in the non-diabetic controls. A delay in insulin response to glucose was noted in many of the offspring as indicated by a low deltaI/deltaG at 30'. We conclude that offspring of diabetic parents with nephropathy do not show higher risk of glucose intolerance or insulin resistance compared to those with diabetic parents without nephropathy. The relatively high plasma glucose values in the presence of normal insulin secretion in both groups of offspring of diabetic parents suggest the presence of insulin resistance.

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.

Allelic variation in the vitamin D receptor influences susceptibility to IDDM in Indian Asians

Vitamin D has important immunomodulatory properties and prevents development of diabetes mellitus in an animal model of insulin-dependent diabetes (IDDM). We have studied the vitamin D receptor locus as a candidate for genetic susceptibility to IDDM in Southern Indian families. We found evidence for an association of one particular vitamin D receptor allele with IDDM susceptibility in this community. Ninety-three South Indian families consisting of available parents and an affected offspring were genotyped for three vitamin D receptor polymorphisms using the restriction enzymes TaqI, ApaI and BsmI as well as an adjacent microsatellite located to 12q14 (D12S85). Transmission disequilibrium testing analysis was used to assess preferential transmission of polymorphic markers and haplotypes with IDDM. There was significant excess transmission of vitamin D receptor alleles containing the BsmI restriction site to affected offspring in these families (p = 0.016). No association was found between D12S85 and IDDM. This study suggests that a polymorphism within or close to the vitamin D receptor gene may modify susceptibility to IDDM in this ethnic group.

Risk of noninsulin dependent diabetes mellitus conferred by obesity and central adiposity in different ethnic groups: a comparative analysis between Asian Indians, Mexican Americans and Whites

Epidemiological data from Asian Indians from Madras (AI) and Mexican Americans (MA) and non-Hispanic Whites (NHW) from San Antonio heart study were compared to determine the possible contributions by the anthropometric measurements to the varied prevalence of noninsulin dependent diabetes mellitus (NIDDM) in these ethnic groups. MA had the highest rate of obesity (mean body mass index (BMI) 28.9 +/- 5.9 kg/m2) and the highest prevalence of diabetes (men 19.6%; women 11.8%, P < 0.001 vs other groups). NHW although had high rates of obesity (mean BMI 26.2 +/- 5.2 kg/m2) had low prevalence of diabetes (men 4.4%; women 5.7%) than the AI (men 9.9%; women 5.7%) (Mean BMI 22.3 +/- 4.4 kg/m2, P < 0.001). Although AI had lower BMI than MA, the risk conferred by BMI was similarly high in AI and MA and both the ethnic groups had higher risks than NHW. Impaired glucose tolerance (IGT) was also more prevalent in MA than in AI (men, MA vs AI, 11.8 vs 7.5%, P < 0.003; women 16.1 vs 5.5%, P < 0.001). NHW had lower prevalence of IGT in men (5.7%) and women (6.3%) which were significantly lower (P < 0.001) compared to MA only. Age and BMI were predictive factors of NIDDM in all, while waist to hip ratio (WHR) was significant only in AI and MA, although NHW had high WHR. This may be an indicator of differences in genetic susceptibility. This study also highlights the similarity in risk factors between AI and MA living in urban environment and the significance of distribution of adiposity in the comparatively lean AI.

Involvement of host factors in transcription from baculovirus very late promoters -- a review

The baculovirus expression vector system has emerged as the system of choice for the expression of a number of heterologous genes of both prokaryotic and eukaryotic origin. This system utilizes the baculovirus very late, hyperactive polyhedrin and p10 promoters to drive the transcription of foreign genes. Regulation of transcription from these promoters is presently not well understood even though a number of viral gene products that may be important for transcription have been identified. Fresh insight into host-virus interactions during baculovirus pathogenesis is now offered by the identification of insect host factors that interact with transcriptionally essential motifs of these promoters as well as cis-acting enhancer-like elements upstream from the promoter.