Two case reports of macrovascular complications in fibrocalculous pancreatic diabetes

Fibrocalculous pancreatic diabetes (FCPD) is a form of diabetes secondary to chronic, non-alcoholic pancreatitis in tropical countries. Being a secondary form of diabetes, vascular complications are believed to be rare. In this paper we present two case reports of macrovascular complications (myocardial infarction and gangrene). This shows that large vessel disease does occur in FCPD.

Retinopathy in insulin dependent diabetes mellitus (IDDM) in south India

The prevalence of diabetic retinopathy was assessed by direct and indirect ophthalmoscopy in a group of patients with insulin dependent diabetes mellitus (IDDM). Fourteen percent of patients had retinopathy. Proliferative retinopathy and severe background retinopathy including maculopathy were both seen in four percent of patients. It is possible that the lower prevalence rates for these complications is due to the shorter duration of diabetes in our patients.

Fibrocalculous pancreatic diabetes in the elderly

Fibrocalculous pancreatic diabetes (FCPD) is a form of diabetes seen in tropical countries. It is secondary to chronic, calcific, non-alcoholic pancreatitis. FCPD is usually a disease of youth. This paper reports on two elderly onset cases of FCPD. Macrovascular complications are usually rare in FCPD patients. These two patients had evidence of macrovascular diseases probably due to the older age group of the patients.

Decreased insulin binding in Asian Indian women with gestational diabetes mellitus

Insulin binding to erythrocyte insulin receptors was studied in 10 women with gestational diabetes and compared with 10 matched, normal, pregnant women and 10 normal, non-pregnant controls, with no family history of diabetes. Pregnant women had higher mean fasting and post-glucose plasma immunoreactive insulin (IRI) compared to non-pregnant controls (p less than 0.001). Women with gestational diabetes had higher mean fasting and post-glucose plasma glucose levels and a lower mean specific binding of insulin when compared with the other two groups (p less than 0.001). The decreased insulin binding was significant only at lower insulin concentrations (0.2-2 ng/ml) when compared with those of normal pregnant women (p less than 0.01), suggesting decreased receptor affinity with no change in receptor number. In addition, an increased mean ED50 value for 50% inhibition of maximal binding and a lower mean average affinity constant Ke (empty site) obtained in gestational diabetes in comparison to the other two groups also suggested de decreased affinity of the receptor. The finding that pregnancy with normal glucose tolerance was not accompanied by changes in insulin binding against decreased insulin binding and affinity observed in gestational diabetes suggested a pathogenetic role for impaired insulin binding as one of the factors responsible for insulin resistance and hyperglycemia in gestational diabetes.

Exocrine pancreatic function in tropical fibrocalculous pancreatic diabetes

Exocrine pancreatic function was studied by fecal chymotrypsin test in three groups of diabetic patients seen in southern India. Exocrine pancreatic insufficiency, as shown by low fecal chymotrypsin levels, was seen in 87.5% of patients with fibrocalculous pancreatic diabetes (FCPD), in 23.5% of insulin-dependent diabetes mellitus patients, and in 4.5% of non-insulin-dependent diabetes mellitus patients. There was no correlation between fecal chymotrypsin levels and serum amylase, serum lipase, age, body mass index, duration of diabetes, fasting plasma glucose, or glycosylated hemoglobin levels. The fecal chymotrypsin test is a useful additional investigation for the diagnosis of FCPD found in tropical countries.

The genetic predisposition to fibrocalculous pancreatic diabetes

Fibrocalculous pancreatic diabetes (previously known as tropical pancreatic diabetes) is a rare cause of diabetes confined to countries within the tropical belt. The aetiology of fibrocalculous pancreatic diabetes is thought to be environmental although the agent(s) is unknown. We have investigated a possible genetic basis of this disease by looking for restriction fragment length polymorphisms of genes implicated in the aetiology of diabetes mellitus. Seventy-six Dravidian patients with fibrocalculous pancreatic diabetes were studied, and the restriction fragment length polymorphisms obtained compared to racially matched control subjects (n = 94), patients with Type 2 (non-insulin-dependent) diabetes (n = 87) and Type 1 (insulin-dependent) diabetes (n = 58). No association of fibrocalculous pancreatic diabetes was found with restriction fragment length polymorphisms of the insulin receptor gene. Although no association of fibrocalculous pancreatic diabetes was found with polymorphism of the HLA DR alpha/DQ alpha/DX alpha genes, an association was found with the Taq 1 restriction fragment length polymorphisms of the DQ beta gene (DQ beta T2/T6 present in 39% of patients with fibrocalculous pancreatic diabetes compared to 19% in control subjects; p = 0.01; corrected p value = 0.04) which is similar to that found in Type 1 but not Type 2 diabetes. An association of fibrocalculous pancreatic diabetes was also found with the hypervariable region in the 5-prime flanking region of the insulin gene; 40% of patients possessed the class 3 allele compared to 9.5% of control subjects p = 0.0001; corrected p value = 0.0008).(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin resistance in Fibrocalculous (tropical) pancreatic diabetes

Insulin resistance was assessed by Insulin Tolerance Test (ITT) in 12 patients with FCPD, 10 with NIDDM and 12 age and sex matched control subjects. The mean BMI of the FCPD was lower than the NIDDM and control groups (P less than 0.001). There was no significant difference between the mean fasting plasma glucose or HbA1 between the FCPD and NIDDM patients. The mean fasting C-peptide of the FCPD group was significantly lower than the NIDDM and control groups (P less than 0.001). The mean glucose disposal rate (KITT) was 5.57 +/- 2.28 in the control group, 2.15 +/- 2.00 in the FCPD and 1.77 +/- 0.91 in the NiDDM group (P less than 0.001, control vs FCPD and NIDDM). The difference in KITT between FCPD and NIDDM groups was not significant statistically. The data suggests that patients with FCPD have evidence of insulin resistance and this is similar to that seen in NIDDM patients.

Erythrocyte insulin binding abnormalities in fibro calculous pancreatic diabetes

Insulin binding to erythrocyte insulin receptors was studied in 17 patients (13 men and 4 women) with fibrocalculous pancreatic diabetes mellitus (FCPD) and compared with that of 14 newly diagnosed NIDDM patients matched for age, sex and severity of hyperglycemia, and 14 age and sex-matched non-diabetic control subjects. In the uncompensated diabetic state, mean (+/- S.D.) specific binding of insulin was lower in both FCPD and NIDDM patients, compared with non-diabetic controls (P less than 0.001). Control of diabetes with short term therapy (2-6 weeks) resulted in a significant improvement in the mean specific insulin binding in both FCPD and NIDDM patients (P less than 0.001) due to increased binding affinity in the former, and increased affinity and the number of binding sites in the latter. As compared to short term therapy, chronic therapy (5-8 months) in FCPD patients resulted in a marginal decrease in specific insulin binding. However, this was still significantly higher than the basal value (P less than 0.05). FCPD patients had an initial low mean basal plasma IRI and a much lower mean stimulated IRI response as compared to NIDDM and non-diabetic controls.

Abnormalities in erythrocyte insulin binding in offspring of conjugal non-insulin-dependent diabetic parents

Insulin binding to erythrocyte insulin receptors was studied in 23 offspring (13 men and 10 women) born of conjugal diabetic parents having type 2 diabetes. Nine of the offspring were obese and 14 were non-obese, but all had normal glucose tolerance. Twenty-three age-, sex- and weight-matched non-diabetic subjects without a family history of diabetes were studied as controls. In the non-obese offspring mean basal plasma immunoreactive insulin (IRI) was elevated (P less than 0.01), but the mean stimulated IRI showed no change in comparison to that of controls. In the obese offspring mean basal plasma IRI was similar, but the mean stimulated IRI was lower than that of obese controls (P less than 0.01). Mean specific insulin binding was decreased in both obese (P less than 0.01) and non-obese (P less than 0.01) offspring when compared with the respective controls. Scatchard analysis of the binding data and the higher insulin concentrations required to achieve 50% inhibition of tracer binding indicated decreased receptor affinity in both obese and non-obese offspring. Analysis by average affinity profiles also indicated decreased receptor affinity, as shown by a lower average affinity constant Kc for the empty sites, in the offspring in comparison to that of controls (P less than 0.001). Abnormalities in insulin binding to its receptor along with decreased affinity in the face of normal glucose tolerance may be an early biochemical marker of potential diabetes in this group at high risk of developing diabetes.

High prevalence of diabetes in an urban population in south India

An urban population in a township in south India was screened for diabetes with an oral glucose tolerance test, every fifth person aged 20 and over registered at the local iron ore company's hospital being screened. Of 678 people (346 men and 332 women) who were tested, 34 (5%; 20 men and 14 women) had diabetes and 14 (2%; 8 men and 7 women) had impaired glucose tolerance. Thirteen subjects were already known to be diabetic. Diabetes was present in 21% (37/179) of people aged over 40. The peak prevalence (41%; 7/17) was in the group aged 55-64. A family history of diabetes was present in 16 of the 34 subjects with diabetes and nine of the 15 with impaired glucose tolerance. Diabetes was significantly related to obesity in women but not in men (57% (8/14) v 5% (1/20)). The plasma glucose concentration two hours after glucose loading was correlated to body mass index, age, and income in both sexes. The prevalence of diabetes was significantly higher in subjects whose income was above the mean. When the overall prevalence of diabetes was adjusted to the age distribution of the Indians living in Southall, London, and in Fiji it increased to 10% and 9%, respectively. The prevalence of diabetes is high among urban Indians and is comparable with the high prevalence seen in migrant Indian populations.

Rapid improvement in insulin binding to erythrocyte insulin receptors in non-insulin-dependent diabetes mellitus during therapy

Insulin binding to erythrocyte receptors was studied in 36 newly diagnosed male subjects with NIDDM, treated with diet alone (Group I; n = 10) or diet + glibenclamide (Group II; n = 12) or diet + glibenclamide + metformin (Group III; n = 14). Fourteen matched non-diabetic subjects were also studied as controls. Initially, mean (+/- SD) specific insulin binding was lower in NIDDM patients than in controls (p less than 0.001), due to decreased receptor number and affinity. Control of diabetes with short-term therapy (10 +/- 2 days) resulted in significantly increased specific insulin binding in Groups II and III (p less than 0.001). A marginal increase was observed in Group I (p less than 0.01). The improved insulin binding observed in Group II and III patients after short-term therapy was maintained even after long-term therapy (9 +/- 1 months). Analysis of the insulin binding data by Scatchard plots and average affinity profiles indicated increased receptor number and affinity after short-term therapy. However, changes in affinity were reversed with long-term therapy in Groups II and III and the predominant effect appeared to be an increase in the number of binding sites.

Prevalence of non-insulin-dependent diabetes mellitus in Asian Indian families with a single diabetic parent

Offspring of one parent diabetic (OPDR-A) and offspring of one parent diabetic with a first-degree family history on the non-diabetic parental side (OPDR-B) were studied to assess the influence of familial aggregation on the prevalence of non-insulin-dependent diabetes mellitus (NIDDM). All parents and offspring were tested for diabetes by oral glucose tolerance test. All parents had NIDDM. The prevalence of diabetes was 36% and 54% in the OPDR-A and OPDR-B families, respectively. The prevalence rate in OPDR-B was higher compared to OPDR-A families (P less than 0.01). The prevalence of diabetes in OPDR families was not different whether the father or the mother had diabetes. There was a male predominance among the diabetic offspring. The age at diagnosis was lower in the offspring compared to that in their parents in both groups. The expected risk of diabetes was greater in OPDR-B families compared to OPDR-A families. Thus it is seen that there is high prevalence of NIDDM in our population even in families with only one diabetic parent.

Pancreatic B-cell function in relation to diabetic retinopathy in Asian Indian NIDDM patients

Pancreatic B-cell function in relation to diabetic retinopathy was studied in 195 NIDDM patients with long-standing diabetes. Background diabetic retinopathy (BDR) was present in 95 (48.7%) and proliferative retinopathy (PDR) in 17 (8.7%) of the subjects. There was no significant difference between the BDR, PDR, and non-retinopathy groups with respect to age, age at diagnosis of diabetes and HbA1 values. Mean duration of diabetes was higher in the PDR group (p less than 0.05). Serum C-peptide values showed no correlation with the presence of retinopathy or with the duration of diabetes. The C-peptide values were widely scattered in patients with BDR and PDR showing no association between pancreatic B-cell reserve and occurrence or severity of retinopathy in NIDDM patients. Thus, decreased pancreatic B-cell reserve does not appear to be a risk factor for diabetic retinopathy in NIDDM patients.

Clinical features of diabetes in the young as seen at a diabetes centre in south India

This study reports on the clinical pattern of 545 consecutive young diabetic patients with age at onset below 30 years attending a diabetes centre in Southern India. Three hundred and fourteen patients (57.7%) were classified as having non-insulin-dependent diabetes of the young (NIDDY), 119 (22%) as insulin-dependent diabetes (IDDM) and 28 (5%) as malnutrition-related diabetes (MRDM); 4% fibrocalculous pancreatic diabetes and 1% protein-deficient pancreatic diabetes. The remaining 84 patients could not be classified into any of the above categories. A positive family history of diabetes was more common in NIDDY compared to the other groups (P less than 0.001). While 40.3% of patients with IDDM had age at onset below 15 years, the other types of diabetes were rarely seen in patients younger than this. Body mass index (BMI) did not reliably indicate the MRDM forms of diabetes as 70% of patients with IDDM also had a BMI of less than 18, one of the criteria recommended for the diagnosis of MRDM. C-peptide levels in MRDM were intermediate between the IDDM and NIDDY groups. Microvascular complications were present in all the groups of young diabetics. The frequency was higher in NIDDY patients who also had a longer duration of diabetes. There was an increasing prevalence of complications with increasing duration of diabetes.

HLA-D region RFLPs indicate that susceptibility to insulin-dependent diabetes in South India is located in the HLA-DQ region

Recently close markers for insulin-dependent diabetes mellitus in Western 'Caucasoid' subjects have been defined from DQ region (both alpha and beta genes) restriction fragment length polymorphisms. In order to define the genetic contribution to insulin-dependent diabetes mellitus in an Indian population we have analysed 58 unrelated Dravidian (South Indian) insulin-dependent diabetic patients and 43 controls. In insulin-dependent diabetes an increased frequency of the Taq 1 DQ beta restriction fragment length polymorphisms designated T2 omega/T6 (relative risk = 10.6), and of homozygotes for Taq 1 DQ alpha 4.6 kb (relative risk = 11), was found in the patients. The highest relative risk for insulin-dependent diabetes mellitus was obtained by comparing patients and control subjects who either (a) co-inherited DQT2 omega/T6 with certain DQ alpha restriction fragment length polymorphisms or (b) were DQ alpha 4.6 kb homozygotes, the combination of (a) and (b) accounting for 55.5% of insulin-dependent diabetes mellitus subjects and none of the controls (relative risk = 101; 95% confidence limits 93-109).

Autonomic neuropathy in leprosy

21 patients of borderline lepromatous and lepromatous leprosy of both sexes were taken for study after exclusion of autonomic disorders. Autonomic functions pertaining to cardiovascular and genital system were carried out. Five healthy volunteers served as controls. Autonomic function tests indicate definite involvement of cardiovascular and genital system. The incidence of autonomic neuropathy in 21 patients studied was ranging from 14.3 to 57% for various tests. There is involvement of parasympathetic system (vagus nerve) which occurred early and more common than sympathetic. The sympathetic damage is always associated with parasympathetic damage. The severity of autonomic neuropathy is found to be high in leprosy of longer duration. Autonomic neuropathy widely occurs in leprosy as in diabetes mellitus.

Autonomic neuropathy in leprosy

21 patients of borderline lepromatous and lepromatous leprosy of both sexes were taken for study after exclusion of autonomic disorders. Autonomic functions pertaining to cardiovascular and genital system were carried out. Five healthy volunteers served as controls. Autonomic function tests indicate definite involvement of cardiovascular and genital system. The incidence of autonomic neuropathy in 21 patients studied was ranging from 14.3 to 57% for various tests. There is involvement of parasympathetic system (vagus nerve) which occurred early and more common than sympathetic. The sympathetic damage is always associated with parasympathetic damage. The severity of automatic neuropathy is found to be high in leprosy of longer duration. Autonomic neuropathy widely occurs in leprosy as in diabetes mellitus.

HLA-DR and -DQ DNA genotyping in insulin-dependent diabetes patients in South India

Restriction fragment length polymorphisms (RFLPs) of the HLA-DR beta, -DQ alpha, -DQ beta, and -DX alpha genes have been examined in South Indian diabetic patients and controls. The DR. DQ linkage arrangements in South Indians were shown to be different for DR2, DR4, and DRw6 from those commonly seen in Europeans, so that localization of the primary disease-promoting gene in IDDM could be attempted. This study clearly implicates at least one DQ beta allele in the pathogenesis of IDDM.

Pancreatic beta cell response in insulin treated NIDDM patients limitations of a random C-peptide measurement

Pancreatic beta cell function was evaluated in 30 insulin treated non-insulin dependent diabetic patients, by estimating serum C-peptide after meal stimulation. C-peptide response was low (less than 0.6 pmol/ml) in 15 patients and it was significant (greater than 0.6 pmol/ml) in the other 15 patients. All the patients were then started on a high carbohydrate, high fibre diet and a combination of glibenclamide and metformin. In 18 patients, optimal regulation of hyperglycemia was achieved in one week and the others required insulin treatment. Among the 15 with low C-peptide values, 8 patients responded to oral hypoglycaemic agents and their C-peptide responses improved (from 0.17 +/- 0.16 to 0.78 +/- 0.2 pmol/ml). Among the 15 with significant C-peptide values, 10 responded well to oral drugs and their C-peptide values improved further (from 0.79 +/- 0.21 to 1.17 +/- 0.44 pmol/ml); but the others required insulin despite the good beta cell reserve. This study shows that the beta cell response in insulin treated NIDDM varies widely as it is influenced by the exogenous insulin and hyperglycaemia a random estimation of C-peptide will be of limited value in predicting the response to therapy.

Multiple relapses in borderline leprosy--a case report

A case of borderline lepromatous leprosy with a history of 5 years duration of disease, was first seen in 1971 and treated with graded doses of dapsone in the OP Clinic of the Institute. He became inactive and bacteriologically negative in 3 years. While continuing on dapsone therapy he relapsed into active dapsone resistant leprosy 3 1/2 years later. He was admitted in the hospital and given Rifampicin 600 mg. daily for 15 days along with dapsone 100 mg. daily. He again became inactive and bacteriologically negative within 3 years. 3 years later under regular dapsone therapy he relapsed again for the second time into active BT leprosy, but remained bacteriologically negative. He was given 3 drug regimen subsequently and became clinically inactive within 15 months.

Beta cell function in insulin-treated non-insulin-dependent diabetic patients

Non--insulin-dependent diabetes mellitus (NIDDM) patients, 94 in number, who were treated with insulin for various reasons for periods ranging from 2 to 10 years, were investigated to study the effect of long-term insulin therapy and also the effect of anti-insulin antibodies on the beta cell function. Insulin antibody titer and the stimulated C-peptide (CP) did not correlate with the duration of insulin therapy, dose of insulin, or the severity of hyperglycemia. The antibody titers were low in 45%, moderate in 10%, and high in 45%; no correlation was found between the antibody titers and the CP values. Satisfactory control of hyperglycemia was obtained in 54 patients after change of treatment to oral hypoglycaemic agents (OHA). The other 40 patients required continued insulin therapy. The initial CP values were similar in both the groups before initiating the new therapeutic patterns. Those who responded to OHA showed improved CP values on follow-up. The beta cell response to exogenous insulin is heterogeneous in NIDDM patients. In many patients, adequate preservation of beta cell function is present even after long-term insulin therapy. Many of them respond to OHA. Insulin antibodies do not influence the secretory status of the beta cells in NIDDM patients.

Errors in clinical assessment of glycemic control in patients with non-insulin-dependent diabetes mellitus

Errors in the assessment of glycemic control by clinicians, using the conventional method, based on random blood glucose and clinical parameters other than HbA1, were assessed in 125 non-insulin-dependent diabetic (NIDDM) patients (Group B). The expected mean post-prandial plasma glucose concentrations (y) for these patients were obtained from their HbA1 values (x) using the regression equation y = 39.6 X x - 157.6. This equation was derived using the data from 35 NIDDM patients (Group A), in whom mean post-prandial plasma glucose concentrations (measured twice daily), correlated excellently (r = 0.82; n = 100; p less than 0.001) with mean HbA1 values (measured monthly) determined over a period of 3 months. A comparison of the observed and expected post-prandial plasma glucose concentrations in Group B indicated that only an overall 42% of the total (n = 455) observed values (as against 60% in Group A) fell within the 99% confidence limits of the expected mean value. Fifty-eight % of the observed plasma glucose values fell outside the expected range of which 36% were underestimates and 22% were overestimates. Thus, we concluded that even in patients with stable diabetes the physician's assessment of the overall degree of glycemic control should be based on both plasma glucose and HbA1 concentrations for optimizing therapeutic measures.

Significance of impaired glucose tolerance in an Asian Indian population: a follow-up study

A prospective study was undertaken in 107 Indians with impaired glucose tolerance (IGT) for a period ranging from 2 to 10 years. On follow-up, 32% still had an impaired glucose tolerance, 32% reverted to normal glucose tolerance and 36% developed diabetes. Careful dietary adherence and weight reduction were found to favour normalisation of glucose tolerance. Poor dietary adherence, persistent obesity and weight gain were found to precipitate diabetes. The study stresses the need for intensive diet therapy in individuals with IGT. Insulin responses were heterogeneous in IGT and non-predictive of the follow-up changes in glucose tolerance.

Altered tissue oxygen tension responsiveness in diabetes

Subcutaneous oxygen tension (tissue PO2) was measured by a polarographic method in the legs of insulin-dependent diabetics (IDDM) and controls. Current flow was measured continuously using a five-stage protocol: baseline; 4 min of complete arterial occlusion; during recovery from ischemia; baseline approximately re-established; induction of hyperemia by local application of heat. Eleven patients with IDDM of 4-32 years of duration, without peripheral arterial disease, were studied and compared with 10 controls. The mean baseline subcutaneous PO2 in diabetics was less than controls; however, the difference was not statistically significant. At the end of arterial occlusion the mean decrease in tissue PO2 was less (P less than 0.025) in diabetics (4.7 +/- 0.9 mm Hg, SEM) compared to controls (10.2 +/- 1.6 mm Hg). With induction of hyperemia the increase in tissue PO2 was lower (P less than 0.001) in diabetics (7.4 +/- 0.4 mm Hg) than in controls (18.6 +/- 1.7 mm Hg). The observed differences provide for the first time direct evidence of altered tissue PO2 responses in diabetes.

Beta cell function in long term NIDDM (type 2) patients and its relation to treatment

Pancreatic beta cell function was assessed by estimation of fasting and post prandial plasma C-peptide in 183 non-insulin dependent diabetic patients, who were treated with oral hypoglycaemic drugs, for more than 10 years. One-hundred-and-forty-one patients, continued to respond to oral hypoglycaemic agents (Group I) and in 42 the control was not satisfactory and had to be changed over to insulin (secondary failure, Group II). Significant beta cell reserve (PP CP greater than or equal to 0.6 pmol/ml) was present in 89 out of 183 patients (48%) and 83 (93%) of them responded to oral hypoglycaemic agents. Among the 94 patients with low beta cell reserve, 58 (62%) were on oral hypoglycaemic agents and the other 36 (38%) were on insulin. Of the 42 patients with secondary failure to the oral drugs, 36 (86%) had low C-peptide while 6 (14%) had significant C-peptide values. Secondary failure to oral hypoglycaemic agents can also occur in spite of good beta cell reserve. Beta cell reserve was not correlated either to the duration of diabetes or the age at diagnosis of the patients.

Peripheral neuropathy in tropical pancreatic diabetes

Electrophysiological evaluation of peripheral neuropathy was done in 16 patients with tropical pancreatic diabetes (TPD) and the data compared with those of a matched group of 16 NIDDM patients. Peripheral neuropathy was present in 6 TPD and 5 NIDDM patients. Abnormal motor conduction velocity in the lateral popliteal nerve was seen in 9 TPD patients and in 8 NIDDM patients and biothesiometry was abnormal in 7 patients in each group. One TPD patient had an abnormal F wave in the lower limb. An abnormal sensory potential was recorded in the sural nerve in 6 TPD and 8 NIDDM patients. The study showed that occurrence of peripheral neuropathy in TPD was similar to that in NIDDM. Subclinical neuropathy could be detected by electromyographic recording in both groups of patients.

Insulin response in obese and nonobese offspring of conjugal Indian diabetic parents with increasing glucose intolerance

Pancreatic beta cell function in response to glucose was assessed in three different groups of offspring of conjugal diabetic parents (OCDP): those with normal glucose tolerance, those with impaired glucose tolerance (IGT), and those with diabetes. Serum immunoreactive insulin (IRI), C-peptide (CP), insulin/glucose (I/G) ratio, and IRI/CP ratios were estimated at fasting and 90 min after glucose load. Insulin secretion, measured as CP, was found to be low even in normal nonobese OCDP, but the change was not reflected in IRI value as the IRI/CP ratio was found to be elevated. The values decreased with increasing glucose intolerance. In obese OCDP, all the parameters were abnormal even among those with normal glucose tolerance, and further deterioration occurred with increasing glucose intolerance. The study shows that insulin secretory defects are detectable even in normal OCDP, and these changes deteriorate with increasing glucose intolerance. Differences are noted in the peripheral concentrations of IRI and CP between obese and nonobese OCDP before development of diabetes. After development of diabetes mellitus, these differences disappear, and the CP and IRI values in both groups are similar and low.

Abnormalities in insulin secretion in healthy offspring of Indian patients with maturity-onset diabetes of the young

Serum C-peptide (CP) and immunoreactive insulin (IRI) responses were studied in 47 euglycemic offspring of patients with maturity-onset diabetes of the young (MODY). Mean IRI responses were not significantly different in nonobese offspring of MODY patients (O-MODY) but they were lower in obese O-MODY than in respective controls. Mean CP responses were low in both groups, the change being more pronounced in obese O-MODY. These findings indicate that alterations of secretion and metabolism of insulin can be detected even before glucose intolerance is seen in O-MODY.

High prevalence of type 2 (non-insulin-dependent) diabetes among the offspring of conjugal type 2 diabetic parents in India

The prevalence of Type 2 (non-insulin-dependent) diabetes among offspring of conjugal Type 2 diabetic parents in India was determined by performing oral glucose tolerance tests. Diabetes was present in 50% of offspring, and 12% had impaired glucose tolerance according to the National Diabetes Data Group criteria. Thus, 62% of all offspring had abnormal glucose tolerance tests. This is the highest prevalence rate for diabetes among offspring of conjugal diabetic parents and might represent an ethnic variation of the genetic factors operating in Indian patients with Type 2 (non-insulin-dependent) diabetes.

Insulin and C-peptide responses to glucose load in cystic fibrosis

Immunoreactive Insulin and C-peptide responses to glucose load were estimated in patients with cystic fibrosis and in controls. Both insulin and C-peptide responses were low in cystic fibrosis patients and the changes were more marked in those with glucose intolerance. There appears to be true pancreatic hyposecretion of insulin in patients with cystic fibrosis whereas the peripheral sensitivity of insulin seems to be normal or enhanced.

Retinopathy in tropical pancreatic diabetes

In a study of the retinopathy profile of 40 patients with tropical pancreatic diabetes, a form of secondary diabetes seen in tropical countries, diabetic retinopathy was detected in 13 patients. Ten patients had background retinopathy and three patients had proliferative retinopathy requiring laser photocoagulation. In two patients, fibrous retinitis proliferans was present. Three patients had evidence of diabetic maculopathy. To our knowledge, this is the first report of severe and sight-threatening retinopathy occurring with secondary diabetes. Retinopathy in these forms of diabetes has hitherto been considered to be rare or, if present, only of a mild background type.