High prevalence of maturity-onset diabetes of the young (MODY) among Indians

Identification of appropriate biochemical parameters and cut points to detect Maturity Onset Diabetes of Young (MODY) in Asian Indians in a clinic setting

Maturity Onset Diabetes of the Young (MODY) is a monogenic form of diabetes which is detected by genetic testing. We looked at clinical and biochemcial variables that could help detect possible MODY among Asian Indians with youth-onset diabetes. From the diabetes electronic medical records of a diabetes care centre in Chennai in southern India, demographic, anthropometric, and biochemical details of 34 genetically confirmed MODY participants were extracted. They were compared with patients with type 1 diabetes (T1D) (n = 1011) and type 2 diabetes (T2D) (n = 1605), diagnosed below 30 years of age. Clinical and biochemical variables including body mass index (BMI), glycated hemoglobin, HDL cholesterol, and C-peptide (fasting and stimulated) were analyzed to determine whether cut points could be derived to identify individuals who could be sent for genetic testing to diagnose or rule out MODY in this ethnic group. The age at diagnosis was higher for T2D (26.5 ± 4.0 years) compared to T1D (18.2 ± 6.1 years) and MODY (17.8 ± 6.0 years). Individuals with MODY had BMI, glycated hemoglobin, total cholesterol, triglycerides, HDL cholesterol, and C-peptide levels which were intermediate between T1D and T2D. The identified probable parameters and their cut points to identify cases for MODY genetic screening were BMI 21.2-22.7 kg/m2, glycated hemoglobin 7.2-10%, HDL cholesterol 43-45 mg/dl, fasting C -peptide, 1.2-2.1 ng/ml and stimulated C-peptide, 2.1-4.5 ng/ml. Asian Indians with MODY have clinical features that are intermediate between T1D and T2D and selected biochemical parameters, especially stimulated C peptide cut points were the most useful to diagnose MODY.

Prevalence, clinical features and complications of common forms of Maturity Onset Diabetes of the Young (MODY) seen at a tertiary diabetes centre in south India

BACKGROUND

Maturity Onset Diabetes of the Young (MODY) is a form of monogenic diabetes caused by mutations in single genes, affecting adolescents or young adults. MODY is frequently misdiagnosed as type 1 diabetes (T1). Though several studies from India have reported on the genetic aspects of MODY, the clinical profile, complications and treatments given have not been reported so far, nor compared with T1D and type 2 diabetes (T2D).

AIM

To determine the prevalence, clinical features, and complications of common forms of genetically proven MODY seen at a tertiary diabetes centre in South India and compare them with matched individuals with T1D and T2D.

METHODS

Five hundred and thirty individuals identified as 'possible MODY' based on clinical criteria, underwent genetic testing for MODY. Diagnosis of MODY was confirmed based on pathogenic or likely pathogenic variants found using Genome Aggregation Database (gnomAD) and American College of Medical Genetics (ACMG) criteria. The clinical profile of MODY was compared with individuals with type 1 (T1D) and type 2 (T2D) diabetes, matched for duration of diabetes. Retinopathy was diagnosed by retinal photography; nephropathy by urinary albumin excretion > 30 µg/mg of creatinine and neuropathy by vibration perception threshold > 20 v on biothesiometry.

RESULTS

Fifty-eight patients were confirmed to have MODY (10.9%). HNF1A-MODY (n = 25) was the most common subtype followed by HNF4A-MODY (n = 11), ABCC8-MODY (n = 11), GCK-MODY (n = 6) and HNF1B-MODY (n = 5). For comparison of clinical profile, only the three 'actionable' subtypes - defined as those who may respond to sulphonylureas, namely, HNF1A, HNF4A and ABCC8-MODY, were included. Age at onset of diabetes was lower among HNF4A-MODY and HNF1A-MODY than ABCC8-MODY, T1D and T2D. Prevalence of retinopathy and nephropathy was higher among the three MODY subtypes taken together (n = 47) as compared to T1D (n = 86) and T2D (n = 86).

CONCLUSION

This is one of the first reports of MODY subtypes from India based on ACMG and gnomAD criteria. The high prevalence of retinopathy and nephropathy in MODY points to the need for earlier diagnosis and better control of diabetes in individuals with MODY.

Clinical experience from a regional monogenic diabetes referral centre in Singapore

AIMS

Monogenic diabetes (also known as maturity-onset diabetes of the young or MODY) affects a subset of individuals with young-onset diabetes. We report our diagnostic work-up experience for such individuals.

METHODS

Serving as a regional secondary-care diabetes centre in a multi-ethnic population, we receive referrals to evaluate MODY from endocrinologists in both public and private practice. Key criteria for consideration of genetic-testing are onset age ≤ 35, negative GAD antibody, no history of diabetic ketoacidosis, strong family history of diabetes and BMI < 32.5 kg/m². A monogenic diabetes registry was set up since 2017 to study their disease trajectories.

RESULTS

We identified 30 out of 175 (17.1%) individuals with likely pathogenic/pathogenic variants. Importantly, 29 out of 30 (96.7%) occurred in clinically actionable genes. A continuous scale combining BMI, hs-CRP and HDL provided 80% (P < 0.001) diagnostic accuracy for MODY in our cohort, achieving a negative predictive value of 0.93 and sensitivity at 0.76. Subtyping MODY prior to genetic testing (if desired) will require specialist domain knowledge and additional biomarkers due to its genetic heterogeneity.

CONCLUSIONS

Through systematic and structured evaluation, the prevalence of MODY is non-trivial (17.1%) in a referral centre. Diagnostic algorithm combining clinical criteria and readily available biomarkers can support clinical decision for MODY genetic testing.

My 40-year journey in diabetes research: The power of collaboration

This article describes a 40 year journey in diabetes research of an Indian diabetologist, starting as an undergraduate medical student. The article describes how collaborations with multiple stake-holders is necessary if one is to advance one's research from the simple studies that one starts with and take it to higher and higher levels. It is also essential that the seeds for doing research are planted early in a medico's life even during undergraduate days, as only then will more doctors take up medical research as a career. Finally, the article demonstrates how it is possible to do good quality research in India if one has the passion and sustained interest in the field even if one is not in a university or academic setup.

Prevalence of Diabetic Retinopathy among Subjects with Known Diabetes in China: The Beijing Eye Study

Purpose

To evaluate the prevalence of diabetic retinopathy and risk factors among patients with self-reported diabetes mellitus in China.

Methods

The Beijing Eye Study, a population-based study on inhabitants aged 40+ years, included 4439 subjects. Fundus photographs of the worse eye from participants with self-reported diabetes were graded.

Results

Fundus photographs ready for evaluation and a filled out questionnaire were available for 4127 (93.0%) subjects. The prevalence of self-reported diabetes was 235/4127 (5.7%). Among the subjects with a self-reported diagnosis of diabetes, diabetic retinopathy was detected on the fundus photographs of 86 (37.1%) subjects, with macular edema in 12 (5.2%) subjects, clinically significant macular edema in 6 (2.6%) subjects, and a vision-threatening stage of the retinopathy in 12 (5.2%) subjects. Diabetic retinopathy was associated with rural region (p=0.004), longer duration of diabetes (p=0.009), use of diabetic medications (p=0.02), and lower education background (p=0.003).

Conclusions

Prevalence of diabetic retinopathy among Chinese patients aged 40+ years with a self-reported diagnosis of diabetes is about 37%, with a vision-threatening stage of the retinopathy detected in 5% of the subjects. About 5.7% of the adult Chinese population report on a known diagnosis of diabetes mellitus, with about 15% of these subjects knowing about the presence of diabetic retinopathy. The frequency of known diabetes mellitus is lower in rural regions than in urban regions, while diabetic retinopathy overall and macular edema among the subjects with known diabetes mellitus were significantly more common in the rural group.

Genetic Testing of Maturity-Onset Diabetes of the Young Current Status and Future Perspectives

Diabetes is a global epidemic problem growing exponentially in Asian countries posing a serious threat. Among diabetes, maturity-onset diabetes of the young (MODY) is a heterogeneous group of monogenic disorders that occurs due to β cell dysfunction. Genetic defects in the pancreatic β-cells result in the decrease of insulin production required for glucose utilization thereby lead to early-onset diabetes (often <25 years). It is generally considered as non-insulin dependent form of diabetes and comprises of 1-5% of total diabetes. Till date, 14 genes have been identified and mutation in them may lead to MODY. Different genetic testing methodologies like linkage analysis, restriction fragment length polymorphism, and DNA sequencing are used for the accurate and correct investigation of gene mutations associated with MODY. The next-generation sequencing has emerged as one of the most promising and effective tools to identify novel mutated genes related to MODY. Diagnosis of MODY is mainly relying on the sequential screening of the three marker genes like hepatocyte nuclear factor 1 alpha (HNF1α), hepatocyte nuclear factor 4 alpha (HNF4α), and glucokinase (GCK). Interestingly, MODY patients can be managed by diet alone for many years and may also require minimal doses of sulfonylureas. The primary objective of this article is to provide a review on current status of MODY, its prevalence, genetic testing/diagnosis, possible treatment, and future perspective.

Probing the Protein-Protein Interaction Network of Proteins Causing Maturity Onset Diabetes of the Young

Protein-protein interactions (PPIs) play vital roles in various cellular pathways. Most of the proteins perform their responsibilities by interacting with an enormous number of proteins. Understanding these interactions of the proteins and their interacting partners has shed light toward the field of drug discovery. Also, PPIs enable us to understand the functions of a protein by understanding their interacting partners. Consequently, in the current study, PPI network of the proteins causing MODY (Maturity Onset Diabetes of the Young) was drawn, and their correlation in causing a disease condition was marked. MODY is a monogenic type of diabetes caused by autosomal dominant inheritance. Extensive research on transcription factor and their corresponding genetic pathways have been studied over the last three decades, yet, very little is understood about the molecular modalities of highly dynamic interactions between transcription factors, genomic DNA, and the protein partners. The current study also reveals the interacting patterns of the various transcription factors. Consequently, in the current work, we have devised a PPI analysis to understand the plausible pathway through which the protein leads to a deformity in glucose uptake.

Undiagnosed MODY: Time for Action

Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes that accounts for at least 1 % of all cases of diabetes mellitus. MODY classically presents as non-insulin-requiring diabetes in lean individuals typically younger than 25 with evidence of autosomal dominant inheritance, but these criteria do not capture all cases and can also overlap with other diabetes types. Genetic diagnosis of MODY is important for selecting the right treatment, yet ~95 % of MODY cases in the USA are misdiagnosed. MODY prevalence and characteristics have been well-studied in some populations, such as the UK and Norway, while other ethnicities, like African and Latino, need much more study. Emerging next-generation sequencing methods are making more widespread study and clinical diagnosis increasingly feasible; at the same time, they are detecting other mutations in the same genes of unknown clinical significance. This review will cover the current epidemiological studies of MODY and barriers and opportunities for moving toward a goal of access to an appropriate diagnosis for all affected individuals.

High prevalence of vitamin D deficiency among newly diagnosed youth-onset diabetes mellitus in north India

OBJECTIVES

Vitamin D deficiency is common at all ages, and low levels of vitamin D have been associated with high incidence of type 1 diabetes. Similar results are not consistent for type 2 diabetes. The aim of the present study was to estimate vitamin D status in newly detected youth-onset diabetes in north India.

SUBJECTS AND METHODS

This was a prospective case control study at a tertiary care hospital in north India. Seventy two newly detected youth-onset diabetes subjects (age < 25 years), and 41 age- and gender-matched healthy controls were studied. In addition to basic information and management regarding their diabetes, metabolic parameters and serum 25(OH)D were measured in both the groups.

RESULTS

Vitamin D deficiency was seen in 91.1% of the subjects with diabetes, and 58.5% of the healthy controls. Mean ±SD 25(OH)D was significantly low, 7.88 ± 1.20 ng/mL in subjects with diabetes against 16.64 ± 7.83 ng/mL in controls. Sixty percent of cases had severe Vitamin D deficiency compared with 8.3% in controls. Levels of vitamin D did not correlate with clinical parameters, such as gender, body mass index; or with biochemical parameters, such as serum calcium, phosphorus, alkaline phosphatase, fasting plasma glucose, and HbA1C.

CONCLUSION

Vitamin D deficiency is common in people with youth-onset diabetes.

Molecular diagnosis of maturity onset diabetes of the young in India

Diabetes is highly prevalent in India and the proportion of younger patients developing diabetes is on the increase. Apart from the more universally known type 1 diabetes and obesity related type 2 diabetes, monogenic forms of diabetes are also suspected to be prevalent in many young diabetic patients. The identification of the genetic basis of the disease not only guides in therapeutic decision making, but also aids in genetic counselling and prognostication. Genetic testing may establish the occurrence and frequency of early diabetes in our population. This review attempts to explore the utilities and horizons of molecular genetics in the field of maturity onset diabetes of the young (MODY), which include the commoner forms of monogenic diabetes.

A prospective multi-centric open clinical trial of homeopathy in diabetic distal symmetric polyneuropathy

OBJECTIVES

To evaluate homeopathic treatment in the management of diabetic distal symmetric polyneuropathy.

METHODS

A prospective multi-centric clinical observational study was carried out from October 2005 to September 2009 by Central Council for Research in Homeopathy (CCRH) (India) at its five institutes/units. Patients suffering from diabetes mellitus (DM) and presenting with symptoms of diabetic polyneuropathy (DPN) were screened, investigated and were enrolled in the study after fulfilling the inclusion and exclusion criteria. Patients were evaluated by the diabetic distal symmetric polyneuropathy symptom score (DDSPSS) developed by the Council. A total of 15 homeopathic medicines were identified after repertorizing the nosological symptoms and signs of the disease. The appropriate constitutional medicine was selected and prescribed in 30, 200 and 1 M potency on an individualized basis. Patients were followed up regularly for 12 months.

RESULTS

Out of 336 patients (167 males and 169 females) enrolled in the study, 247 patients (123 males and 124 females) were analyzed. All patients who attended at least three follow-up appointments and baseline curve conduction studies were included in the analysis.). A statistically significant improvement in DDSPSS total score (p = 0.0001) was found at 12 months from baseline. Most objective measures did not show significant improvement. Lycopodium clavatum (n = 132), Phosphorus (n = 27) and Sulphur (n = 26) were the medicines most frequently prescribed. Adverse event of hypoglycaemia was observed in one patient only.

CONCLUSION

This study suggests homeopathic medicines may be effective in managing the symptoms of DPN patients. Further studies should be controlled and include the quality of life (QOL) assessment.

Genetics of type 2 diabetes mellitus and other specific types of diabetes; its role in treatment modalities

Type 2 diabetes mellitus (T2DM) is among the most challenging health issues of the 21st century and is associated with an alarming rise in the incidence. The pathophysiological processes that lead to development of T2DM are still unclear, however impairment in insulin secretion and/or action is clearly indicated. Type 2 diabetes is a polygenic disorder with multiple genes located on different chromosomes contributing to its susceptibility. Analysis of the genetic factors is further complicated by the fact that numerous environmental factors interact with genes to produce the disorder. Only a minority of cases of type 2 diabetes are caused by single gene defects and one example is maturity onset diabetes of the young (MODY). Previous studies indicated that variants in genes encoding the pancreatic β-cell K+ATP channel subunits Kir6.2 (KCNJ11) and SUR1 (ABCC8) are associated with neonatal diabetes. Six different types of maturity onset diabetes of young (MODY) have been identified based on characteristic gene defect. The common Pro12Ala polymorphism in peroxisome proliferator-activated receptor-γ (PPAR-γ) gene was confirmed in several studies to be associated with type 2 diabetes as well. More recently, studies reported variants within a novel gene, TCF7L2, as a putative susceptibility gene for type 2 diabetes across many ethnic backgrounds around the world. MODY patients respond better to sulphonylureas and metformin, while neonatal diabetes patients with genetic mutations can be changed from insulin to oral drugs. We hereby provide a comprehensive review on the role of genetics in type 2 diabetes mellitus.

Prevalence of depression in relation to glucose intolerance in urban south Indians--the Chennai Urban Rural Epidemiology Study (CURES-76)

BACKGROUND

This study investigated the association between depression and glucose intolerance in urban residents of southern India.

METHODS

Subjects were recruited from the Chennai Urban Rural Epidemiology Study, carried out on a representative sample of 26,001 subjects recruited from Chennai city in southern India. Subjects with known diabetes were excluded (n = 1,498). Of the remaining 24,503 subjects, fasting capillary blood glucose (FBG) estimation were available for 23,787 subjects (response rate, 97.1%) in whom depression was assessed using a validated instrument, the Patient Health Questionnaire-12. Subjects with FBG values ≥126 mg/dL were termed as subjects with newly diagnosed diabetes (NDD), those with values between 100 and 125 mg/dL as having impaired fasting glucose (IFG), and those with <100 mg/dL as having normal fasting glucose (NFG).

RESULTS

The overall prevalence of depression was 14.3% (3391 of 23,787 subjects), and an increasing prevalence of depression was seen with increasing grades of glucose intolerance: NFG (13.1%), IFG (15.7%), and NDD (19.7%) (trend χ(2) = 57.1, P < 0.001). The prevalence of depression was higher in females at all grades of glucose intolerance. Risk for depression was higher among NDD subjects compared to NFG subjects (odds ratio = 1.12, 95% confidence interval 1.03-1.22, P = 0.01) and IFG subjects (odds ratio 1.21, 95% confidence interval 1.02-1.44, P = 0.03) and also for IFG compared to NFG subjects (odds ratio = 1.12, 95% confidence interval 1.02-1.21, P = 0.01) after adjusting for age, gender, body mass index, hypertension, and socioeconomic status.

CONCLUSION

The prevalence of depression increases with increasing grades of glucose intolerance and is highest among those with diabetes.

Diabetes in Asia

Prevalence of type 2 diabetes has rapidly increased in native and migrant Asian populations. Diabetes develops at a younger age in Asian populations than in white populations, hence the morbidity and mortality associated with the disease and its complications are also common in young Asian people. The young age of these populations and the high rates of cardiovascular risk factors seen in Asian people substantially increase lifetime risk of cardiovascular disease. Several distinctive features are apparent in pathogenetic factors for diabetes and their thresholds in Asian populations. The economic burden due to diabetes at personal, societal, and national levels is huge. National strategies to raise public awareness about the disease and to improve standard of care and implementation of programmes for primary prevention are urgently needed.

Prevalence and clinical profile of autosomal dominant type 2 diabetes from a diabetes centre in India

AIMS

To study the prevalence, and clinical profile of autosomal dominant (AD) inherited forms of type 2 diabetes mellitus (T2DM).

METHODS

Detailed pedigree charts were drawn on 510 consecutive T2DM subjects attending a tertiary care diabetes centre in South India. Clinical and biochemical features of T2DM subjects with and without AD inheritance were compared.

RESULTS

Overall, 36.1% of T2DM had one parent with diabetes, in 10.6%, both parents had diabetes and 10.2% had features of AD. Age at diagnosis of diabetes was the lowest among AD group compared to other groups (p for trend <0.001). Only 22.6% of T2DM with AD inheritance had age at diagnosis of diabetes below 25 years and in 26.4%, it was diagnosed above 45 years. There were no significant differences in the clinical features, including prevalence of diabetic complications, between T2DM with and without AD inheritance.

CONCLUSIONS

In this clinic-based study, 10.2% of T2DM subjects had evidence of AD inheritance. While the AD cases occurred at younger age, older age at diagnosis was not uncommon. Clinical features, including complications, did not differ between the T2DM patients with or without AD.

Identification of novel variants in the hepatocyte nuclear factor-1alpha gene in South Indian patients with maturity onset diabetes of young

CONTEXT

Mutations in the HNF 1A gene are the most common cause of maturity-onset diabetes of the young (MODY) in most populations. India currently has the largest number of people with diabetes in the world, and onset of type 2 diabetes occurs at a younger age with possible overlap with MODY. There are very few data on MODY mutations from India.

OBJECTIVE

The objective was to screen coding and promoter regions of HNF1A gene for mutations in unrelated South Indian subjects in whom a clinical diagnosis of MODY was made.

DESIGN

This was an observational cross-sectional study.

SETTING

The study was conducted at a diabetes specialties centre in Chennai in southern India.

PATIENTS

Ninety-six unrelated south Indian subjects in whom clinical diagnosis of MODY was made were included in the study. The control population comprised of 57 unrelated nondiabetic subjects selected from the Chennai Urban Rural Epidemiology Study, a study conducted on a representative population (aged > or =20 yr) of Chennai.

RESULTS

We identified nine novel variants comprising seven mutations (one novel mutation -538G>C at promoter region and six novel coding region mutations) and two polymorphisms in the HNF1A gene. Functional studies revealed reduced transcriptional activity of the HNF1A promoter for two promoter variants. We also observed cosegregation with diabetes of the Arg263His coding region mutation in eight members of one MODY family, whereas it was absent in nondiabetic subjects of this family.

CONCLUSION

This study suggests that mutations in the HNF1A gene comprise about 9% of clinically diagnosed MODY subjects in southern India and a novel Arg263His mutation cosegregates with MODY in one family.

Frequency of diabetic retinopathy in the adult population in China: the Beijing Eye Study 2001

To evaluate the prevalence of diabetic retinopathy and its impact on visual impairment in China. The Beijing Eye Study, a population-based study on inhabitants aged 40+ years in rural and urban regions of Greater Beijing included 4,439 subjects out of 5,324 subjects invited to participate. Fundus photographs of the worse eye per subject were graded using the early treatment of diabetic retinopathy study criteria. The minimum criterion for diagnosis of diabetic retinopathy was the presence of at least one microaneurysm. Gradable fundus photographs were available for 4,391 (98.9%) subjects. Diabetic retinopathy was detected in 285 subjects (6.5% of the total study population). Most of the diabetic retinopathy was of the mild type (91.9%). Eleven subjects (3.9%) had the moderate nonproliferative type, and 12 subjects (4.2%) had proliferative retinopathy. Diabetic retinopathy was associated with age [P < 0.001; odds ratio (OR) 1.02; 95% confidence interval (CI) 1.01, 1.04], and self-reported diagnosis of arterial hypertension (P = 0.036; OR 1.39; 95%CI 1.02, 1.88) and of hyperlipidemia (P = 0.029; OR 1.39; 95%CI 1.04, 1.88). One subject (0.02%) out of the total study population was blind due to diabetic retinopathy. Diabetic retinopathy caused 8% of all blindness in the total study population. Diabetic retinopathy was detected in about 7% of adult Chinese aged 40+ years. Visual impairment due to diabetic retinopathy was relatively uncommon in the adult Chinese population as compared with in Western populations. Factors associated with diabetic retinopathy were age, and self-reported diagnosis of arterial hypertension and of hyperlipidemia.

Etiology of early-onset type 2 diabetes in Indians: islet autoimmunity and mutations in hepatocyte nuclear factor 1alpha and mitochondrial gene

CONTEXT

Indians are at high risk of developing type 2 diabetes mellitus (T2DM) at an early age, despite their lower body mass index. Studies on the etiology of patients presenting as early-onset T2DM in this racial group are not available.

OBJECTIVE

The objective was to delineate the clinical features in young Indian patients with T2DM and to determine the role of mutations in the hepatocyte nuclear factor 1alpha (HNF1alpha) gene [MODY3 (maturity-onset diabetes of the young, type 3)], mitochondrial A3243G mutation, and islet autoimmunity in its etiology.

DESIGN

This was an observational cohort study.

SETTING

The setting was an outpatient diabetes clinic in a teaching hospital.

PATIENTS

Ninety-six consecutive young patients with T2DM (onset, <or=30 yr) were included in the study.

INTERVENTIONS

Glutamic acid decarboxylase and insulinoma antigen 2 antibodies, mitochondrial A3243G mutation, and the common HNF1alpha mutation P291fsinsC were measured in all patients. The entire HNF1alpha gene was studied for mutations in 32 subjects with onset less than 25 yr or with normal weight. The common HNF1alpha A98V polymorphism was studied in 91 patients.

RESULTS

The patients were clinically heterogeneous, with 42% having a normal body mass index. Glutamic acid decarboxylase antibodies were present in three (3%) subjects and mitochondrial A3243G mutation in one (1%) subject. The P291fsinsC mutation was not detected in any patient. A MODY3 mutation (R200W) was detected in one patient (3%). In this family, diabetes cosegregated with the R200W mutation in the proband and his youngest brother but not in three paternal uncles. The Val 98 allele was associated with T2DM (allele frequency, 0.14 vs. 0.03 in controls; odds ratio, 5.2; P < 0.001).

CONCLUSIONS

Despite a significant proportion of young Indian patients with T2DM having normal weight, islet autoimmunity, A3243G mitochondrial, and HNF1alpha gene mutations were infrequent.

Peroxisome proliferator-activated receptor-gamma co-activator-1alpha (PGC-1alpha) gene polymorphisms and their relationship to Type 2 diabetes in Asian Indians

AIMS

The objective of the present investigation was to examine the relationship of three polymorphisms, Thr394Thr, Gly482Ser and +A2962G, of the peroxisome proliferator activated receptor-gamma co-activator-1 alpha (PGC-1alpha) gene with Type 2 diabetes in Asian Indians.

METHODS

The study group comprised 515 Type 2 diabetic and 882 normal glucose tolerant subjects chosen from the Chennai Urban Rural Epidemiology Study, an ongoing population-based study in southern India. The three polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Haplotype frequencies were estimated using an expectation-maximization (EM) algorithm. Linkage disequilibrium was estimated from the estimates of haplotypic frequencies.

RESULTS

The three polymorphisms studied were not in linkage disequilibrium. With respect to the Thr394Thr polymorphism, 20% of the Type 2 diabetic patients (103/515) had the GA genotype compared with 12% of the normal glucose tolerance (NGT) subjects (108/882) (P = 0.0004). The frequency of the A allele was also higher in Type 2 diabetic subjects (0.11) compared with NGT subjects (0.07) (P = 0.002). Regression analysis revealed the odds ratio for Type 2 diabetes for the susceptible genotype (XA) to be 1.683 (95% confidence intervals: 1.264-2.241, P = 0.0004). Age adjusted glycated haemoglobin (P = 0.003), serum cholesterol (P = 0.001) and low-density lipoprotein (LDL) cholesterol (P = 0.001) levels and systolic blood pressure (P = 0.001) were higher in the NGT subjects with the XA genotype compared with GG genotype. There were no differences in genotype or allelic distribution between the Type 2 diabetic and NGT subjects with respect to the Gly482Ser and +A2962G polymorphisms.

CONCLUSIONS

The A allele of Thr394Thr (G --> A) polymorphism of the PGC-1 gene is associated with Type 2 diabetes in Asian Indian subjects and the XA genotype confers 1.6 times higher risk for Type 2 diabetes compared with the GG genotype in this population.

A prevalent amino acid polymorphism at codon 98 (Ala98Val) of the hepatocyte nuclear factor-1alpha is associated with maturity-onset diabetes of the young and younger age at onset of type 2 diabetes in Asian Indians

OBJECTIVE

Among Europeans, mutations in the hepatocyte nuclear factor-1alpha (HNF1alpha) gene are associated with the most common form of maturity-onset diabetes of the young (MODY)3. In Asian Indians, type 2 diabetes occurs earlier and often overlaps with MODY, but the genetics of the latter are unknown. The aim of this study was to estimate the prevalence of Ala98Val polymorphism of the HNF1alpha gene in different types of diabetes in Asian Indians.

RESEARCH DESIGN AND METHODS

Genotyping of Ala98Val was done by the PCR-restriction fragment-length polymorphism method in the following groups: 1) MODY, defined as non-insulin-dependent diabetes (age at onset <25 years) and vertical transmission of diabetes through at least three generations (n = 122); 2) very-early-onset type 2 diabetes (age at onset <25 years) without family history (n = 23); 3) early-onset type 2 diabetes (age at onset between 26 and 40 years, n = 171); 4) late-onset type 2 diabetes (age at onset >40 years, n = 133); 5) type 1 diabetes (n = 150); and 6) normal glucose tolerance (n = 130). The frequency of the Val genotypes was compared in the diabetic and control groups.

RESULTS

The frequency of the Val allele was significantly higher in MODY patients (P = 0.0013) compared with control groups. Furthermore, in the total group of patients with type 2-like diabetes (groups 1-4), the Val allele was associated with an earlier diagnosis of diabetes (P = 0.0002).

CONCLUSIONS

Among Asian Indians, the Ala98Val polymorphism of HNF1alpha gene is associated with MODY and with earlier age at onset of type 2 diabetes.

Type 2 diabetes in Asian-Indian urban children

OBJECTIVE

Due to a background of high prevalence of type 2 diabetes and the increasing rate of obesity occurring in relatively young urban children, we felt the need to look for type 2 diabetes in children.

RESEARCH DESIGN AND METHODS

A study of cases of type 2 diabetes with age at diagnosis of </=15 years seen at a diabetes speciality center in Chennai, India, is reported. A total of 18 children (5 boys and 13 girls) aged 9-15 years with insidious onset of diabetes responding to oral antidiabetic agents (ODAs) for periods from 2 months to 12 years were studied. Clinical details, anthropometry, and details of family history of diabetes were elicited. All of them were tested for the presence of anti-GAD(65) antibodies and for pancreatic beta-cell reserve by measuring serum C-peptide response (radioimmunoassay procedures).

RESULTS

All children showed a response to ODAs, had good beta-cell reserve (>/=0.6 pmol/ml on stimulation), and negligible GAD(65) antibodies indicating the presence of type 2 diabetes. The children were nonketotic; nine were obese, four had acanthosis nigricans, and one had polycystic ovary syndrome. Positive family history of diabetes was present in all cases.

CONCLUSIONS

The clinical, immunological, and biochemical profile showed that the children had type 2 diabetes. The profile of type 2 diabetes was similar to that described in children in many other countries. Although less common than type 1 diabetes, type 2 diabetes in children is a condition that needs to be recognized and looked for in Asian-Indians.

Frequency of proteinuria in type 2 diabetes mellitus seen at a diabetes centre in southern India

The frequency of proteinuria was assessed in a cohort of 1848 diabetic patients attending a diabetes centre in south India. A total of 127 (6.9%) patients had evidence of macroproteinuria and 49 (2.5%) patients had microproteinuria. Thus overall 9.4% of patients had diabetes related proteinuria. In addition, 70 patients (3.8%) had evidence of proteinuria with no evidence of retinopathy. The frequency of both microproteinuria and macroproteinuria increased linearly with duration of diabetes. Multiple logistic regression analysis showed that duration of diabetes, serum creatinine, and glycated haemoglobin were risk factors for macroproteinuria.

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.

Monogenic diabetes mellitus in youth. The MODY syndromes

Maturity onset diabetes of the young is characterized by early onset diabetes inherited in an autosomal dominant pattern. Classic MODY occurs predominantly in Caucasians and presents before age 25, is nonketotic, and is generally not insulin-requiring. Less than 5% of cases of childhood diabetes in Caucasians are caused by MODY. ADM is a subtype of MODY that occurs in approximately 10% of African-Americans with youth onset diabetes. In contrast to MODY in Caucasians, ADM presents clinically as acute onset diabetes often associated with weight loss, ketosis, and even diabetic ketoacidosis. Approximately 50% of patients with ADM are obese. Therefore, based strictly on clinical grounds, at onset, ADM cannot be distinguished from type 1 diabetes. Months to years following diagnosis, a non-insulin-dependent clinical course develops in patients with ADM that is clearly different from type 1 diabetes. Mutations in five genes can cause MODY. These genes encode hepatocyte nuclear factor-4 alpha (HNF-4 alpha, MODY1), glucokinase (MODY2), hepatocyte nuclear factor-1 alpha (HNF-1 alpha, MODY3), insulin promoter factor-1 (IPF-1, MODY4), and hepatocyte nuclear factor-1 beta (HNF-1 beta, MODY5). These monogenic forms of MODY have been used as model systems to investigate the inheritance and pathophysiology of type 2 diabetes. Clinicians, should be able to diagnose MODY. Type 1 diabetes, the most common form of diabetes in Caucasians, is always insulin-requiring for control and survival, whereas patients with MODY do not usually require long-term insulin for survival. Diagnostic confusion can lead to inappropriate management and patient expectations. Primary care physicians must be alert to avoid therapeutic confusion when patients with ADM enter into the non-insulin-dependent stage. An approach to the diagnosis of childhood diabetes is offered in Table 4. The majority of youth onset diabetes remains type 1; however, the frequency of type 2 diabetes is rising in obese children and adolescents and especially in obese minority youth. The diagnosis of MODY can be made through a careful review of the patient's clinical course, severity of hyperglycemia, and family history. The identification of islet autoantibodies is confirmatory evidence of autoimmune (type 1) diabetes. Because testing for MODY mutations is expensive and is performed at a select number of research laboratories only, routine molecular genetic studies to search for the various MODY mutations should be limited to research investigations. In the future, the availability of gene chip technology may allow rapid screening of mitochondrial and MODY mutations.

Familial clustering of type II diabetes mellitus (DM) diagnosed under the age of 40 years in Yemen: Is it early-onset type II DM or maturity-onset diabetes of the young?

BACKGROUND

Clinical presentation of type II diabetes mellitus (DM) has frequently been observed at an early age in developing countries, probably as a result of genetic, epidemiological and demographic factors. This study aimed to investigate the pattern of familial clustering of type II DM in patients who developed clinical diabetes before the age of 40 years.

PATIENTS AND METHOD

The study involved family pedigrees, clinical assessments and laboratory investigations of 191 patients with type II DM, and 260 age-matched randomly selected non-diabetic controls.

RESULTS

The prevalence of type II DM was found to be statistically higher among parents (P<0.0001), fullsiblings (P<0.0001), half-siblings (P<0.001), uncles (P<0.01) and aunts (P<0.001) of the index patients, as compared to the corresponding relatives of nondiabetic controls. The odds ratio of the family history index (FHI), in association with type II DM in probands who had no family history of diabetes (FHI=0.0), was significantly negative (OR=0.34; 95% CI 0.23, 0.52; P<0.0001). At an FHI level of 0.5-1.0, there was a slight nonsignificant increase in odds ratio for diabetes (OR=1.53; 95% CI 0.95, 2.45; P=0.08). A higher level of FHI (A(3)1.5) was associated with a significant increase in odds ratio for diabetes (OR=3.75; 95% CI 2.13, 6.64; P<0.0001). The age-corrected relative risk of type II DM for the offspring of diabetic parents was found to be progressively increasing from a nonconsanguineous diabetic father (22%) or mother (26.5%), to nonconsanguineous conjugal diabetic parents (27%) and to the offspring of consanguineous single or conjugal diabetic parents (37.5%). On the contrary, the age-corrected relative risk for the offspring of nonconsanguineous and consanguineous nondiabetic parents was characteristically lower (14% for each). Maturityonset diabetes of the young (MODY) was suspected in 10 probands (5%), and early-onset type II DM in the offspring of conjugal diabetic parents in 16 probands (9%). The remaining 165 probands (86%) were unclassified due to lack of specific classification criteria.

CONCLUSION

The considerable familial clustering of type II DM diagnosed under the age of 40 years in this study population reflects the presence of a strong genetic component in its etiology. In addition, the development of early-onset type II DM was more likely associated with a consanguineous and/or conjugal diabetic parents and probably MODY subtype among a substantial number of patients. Epidemiological and demographic factors might have been implicated, especially in those with negative parental diabetic history.

Clinical profile of lean NIDDM in South India

The majority (> 80%) of patients with non insulin dependent diabetes mellitus (NIDDM) present in Europe and America are obese. In developing countries like India, most NIDDM (> 60%) are non-obese and many are actually lean with a body mass index (BMI) of < 18.5 and are referred to as 'lean NIDDM'. This paper compares the clinical profile of a cohort of 347 lean NIDDM, with a group of 6274 NIDDM of ideal body weight (IBW) and 3252 obese NIDDM attending a diabetes centre at Madras in South India. The lean NIDDM who constituted 3.5% of all NIDDM patients seen at our centre, had more severe diabetes and an increased prevalence of retinopathy (both background and proliferative), nephropathy and neuropathy. Although a larger percentage of the lean NIDDM patients were treated with insulin, 47% of the males and 53% of the females were still on oral hypoglycaemic agents even after a mean duration of diabetes of 9.2 +/- 8.1 years. Studies of GAD antibodies, islet cell antibodies (ICA) and fasting and stimulated C-peptide estimations done in a small subgroup of the lean NIDDM showed that they were distinct from IDDM patients. More studies are needed on metabolic, hormonal and immunological profile of lean NIDDM seen in developing countries like India.

Non-insulin-dependent diabetes mellitus in childhood and adolescence

NIDDM in children and adolescents represents a heterogeneous group of disorders with different underlying pathophysiologic mechanisms. Most subtypes of NIDDM that occur in childhood are uncommon, but some, such as early onset of "classic" NIDDM, seem to be increasing in prevalence. This observed increase is thought to be caused by societal factors that lead to sedentary lifestyles and an increased prevalence of obesity. In adults, hyperglycemia frequently exists for years before a diagnosis of NIDDM is made and treatment is begun. Microvascular complications, such as retinopathy, are often already present at the time of diagnosis. Children are frequently asymptomatic at the time of diagnosis, so screening for this disorder in high-risk populations is important. Screening should be considered for children of high-risk ethnic populations with a strong family history of NIDDM with obesity or signs of hyperinsulinism, such as acanthosis nigricans. Even for children in these high-risk groups who do not yet manifest hyperglycemia, primary care providers can have an important role in encouraging lifestyle modifications that might delay or prevent onset of NIDDM.

Maturity-onset diabetes of the young (MODY): three case reports and new perspectives

Maturity-onset diabetes of the young (MODY) is a rare form of juvenile diabetes mellitus that presents with hyperglycaemia in the absence of ketosis. We present three cases of MODY, all of whom had pedigrees with diabetics in multiple generations. All our patients presented in adolescence with evidence of insulin resistance. Two patients were relatively overweight. All three patients were readily controlled on diet alone. None had any clinical evidence of diabetic complications in early adulthood. Recently there has been a marked increase in our understanding of MODY. Genetic linkage and mutational analyses have identified three subtypes (MODY1, 2 and 3) that are all transmitted in an autosomal dominant fashion. The pathophysiology of the MODY subtypes is variable with both increased and decreased insulin levels being seen. A failure to recognise MODY will result in a lack of appropriate therapy and the potential for diabetic complications.

Prevalence of retinopathy in non insulin dependent diabetes mellitus at a diabetes centre in southern India

A cohort of 6792 NIDDM patients attending a diabetes centre at Madras in South India was screened using a combination of retinal photography and clinical examination by retinal specialists. A total of 2319 patients (34.1%) had evidence of retinopathy. This included 2090 patients (30.8%) with non-proliferative diabetic retinopathy including 435 patients (6.4%) with maculopathy and 229 patients (3.4%) with proliferative diabetic retinopathy. Multiple logistic regression analyses showed that duration of diabetes, glycosylated haemoglobin, type of treatment (insulin treatment versus non-insulin treatment), systolic and diastolic blood pressures and serum creatinine, showed a positive association with retinopathy while body mass index (BMI) showed an inverse association. The prevalence rates of retinopathy in Southern Indians are comparable to those seen in Europeans. However in view of the high prevalence of diabetes in the Indian sub-continent, diabetic retinopathy could become a formidable challenge in the future.

Vascular complications in long-term south Indian NIDDM of over 25 years' duration

The prevalence of vascular complications was assessed in 726 South Indian non-insulin dependent diabetes mellitus (NIDDM) patients with over 25 years' duration of diabetes. Retinopathy was detected in 52.0% of patients which included 41.7% with non-proliferative and 10.3% with proliferative diabetic retinopathy. Nephropathy was present in 12.7% and neuropathy in 69.8% of patients. While 32.8% of patients had ischaemic heart disease, the prevalence of peripheral vascular disease was only 15.4%. Multivariate logistic regression analyses showed that serum creatinine was associated with retinopathy, creatinine and post-prandial plasma glucose with nephropathy and post-prandial plasma glucose and age with neuropathy. This is one of the first reports on vascular complications in long-term diabetes from the Indian sub-continent.

Prevalence of diabetes in pregnant women--a study from southern India

This study was carried out to assess the prevalence of diabetes in southern Indian women during pregnancy. Nine hundred and fifty women having > or = 24 weeks of gestation, attending two general gynaecology centres for antenatal check-ups were screened. Initially, the screening test with 1-h plasma glucose sampling following 50 g glucose load was done and those with glucose values > or = 140 mg/dl were subjected to a 3-h oral glucose tolerance test (OGTT) with 100 g glucose load. Among the 950 women, 6 were known diabetic subjects. Of the other 944, 89 were positive on screening test and 67 of them reported for OGTT. Four were detected to have gestational diabetes mellitus (GDM) (O'Sullivan and Mahan's criteria). Therefore the prevalences of total diabetes and GDM were 1.19% and 0.56%, respectively.

Glucose tolerance and insulin response in parents of patients with insulin-dependent and juvenile-onset non-insulin-dependent diabetes mellitus

Glucose tolerance and insulin response were examined using a 100 g oral glucose tolerance test (OGTT) in 108 parents of 23 patients with insulin-dependent (IDDM) and 31 patients with non-insulin-dependent diabetes mellitus (NIDDM), whose age of onset of diabetes was less than 35 years. Thirty-two age-matched healthy volunteers without a family history of diabetes were also examined as a control group. Diabetes and impaired glucose tolerance (IGT) were significantly more frequent in parents of NIDDM (diabetes 34%, IGT 27%) than in parents of IDDM (diabetes 7%, IGT 13%) (P less than 0.001). At least one parent had diabetes or IGT in 30% of IDDM and 84% of NIDDM patients (P less than 0.001), and both parents had diabetes or IGT in 9% of IDDM and 39% of NIDDM patients (P less than 0.02). Even in cases with 'normal' glucose tolerance, the mean plasma glucose was higher in parents of NIDDM than in control subjects, suggesting a high prevalence of abnormal glucose tolerance including the marginal degree of abnormality in the families of NIDDM. The early phase insulin response was decreased more among parents of NIDDM with the greater impairment of glucose tolerance. However, among those with 'normal' glucose tolerance, early phase insulin response did not differ between parents of IDDM and NIDDM, and control subjects. The results confirmed a stronger familial background in NIDDM patients of younger onset than in IDDM. The different patterns of glucose tolerance among two parents of young-onset NIDDM patients suggest heterogeneity of the mode of inheritance of NIDDM among families.

Epidemiology of diabetes in Asians of the Indian subcontinent

Asians from the Indian subcontinent have received greater attention in diabetes studies because of their migration in large numbers. The prevalence of non-insulin-dependent diabetes mellitus (NIDDM) in migrant Indians is higher than that in the population residing in the Indian subcontinent and is also usually higher than in the other racial groups in the host country. However, before drawing any conclusions with reference to the high prevalence of NIDDM in the migrant Indians, careful comparisons are required with more up-to-date information available from the Indian subcontinent itself. Recent data from India indeed indicate that the prevalence rates have either been underestimated in the past or are rising. The problem is compounded by the different diagnostic criteria used for defining diabetes. Some of the possible factors which cause variations in the rates of NIDDM in this population are discussed.

Clinical profile of Japanese dialysis patients with diabetic nephropathy, diagnosed as having diabetes before the age of thirty

Diabetic nephropathy is the leading cause of death in young diabetic patients. There are a large number of patients with non-insulin-dependent diabetes mellitus (NIDDM) who are diagnosed before the age of 30 in Japan. We investigated 36 patients with young-onset diabetes who started dialysis between 1978 and 1987 in our hospital. Of the 36 patients, 12 (33.3%) were classified as having insulin-dependent diabetes mellitus (IDDM), 22 (61.1%) had NIDDM, and 2 (5.6%) could not be classified clinically. The percentages of the different types of diabetes in our series of dialysis patients were almost identical with those in Nagai's series of 551 diabetic patients diagnosed before the age of 30 at the Diabetes Center of Tokyo Women's Medical College from 1976 to 1981. The present study showed the young-onset NIDDM in Japan was associated with almost the same incidence of end-stage diabetic nephropathy as was IDDM. However, the number of NIDDM patients diagnosed under 30 years of age was almost double that of IDDM patients. Thus, we have to pay greater attention to the development of diabetic nephropathy in young-onset NIDDM patients than has been thought necessary in the past.

A Chinese family with non-insulin-dependent diabetes of early onset and severe diabetic complications

Non-insulin-dependent diabetes mellitus of early onset has recently been described in Caucasians as a distinct syndrome with a characteristic pedigree suggestive of inheritance of genetic determinants from both parents. It is characterized by absence of islet cell antibodies and the severity of its clinical course. We report a Chinese family pedigree of three generations in which this form of diabetes has affected the third generation. Some members of this pedigree had severe complications at presentation in their twenties.

Fibrocalculous pancreatic diabetes and obesity

Fibrocalculous pancreatic diabetes (FCPD) is a form of diabetes secondary to chronic pancreatitis that is found in tropical countries. Most patients with FCPD are lean and many are frankly undernourished. Four patients with FCPD who were obese are reported in this paper and this is the first report of obesity in FCPD patients.

Maturity-onset diabetes of the young (MODY)

This review summarized aspects of the widening scope, phenotypic expression, natural history, recognition, pathogeneses, and heterogenous nature of maturity-onset diabetes of the young (MODY), an autosomal dominant inherited subtype of NIDDM, which can be recognized at a young age. There are differences in metabolic, hormonal, and vascular abnormalities in different ethnic groups and even among Caucasian pedigrees. In MODY patients with low insulin responses, there is a delayed and decreased insulin and C-peptide secretory response to glucose from childhood or adolescence, even before glucose intolerance appears; it may represent the basic genetic defect. The nondiabetic siblings have had normal insulin responses for decades. The fasting hyperglycemia of some MODY has been treated successfully with sulfonylureas for more than 30 years. In a few, after years or decades of diabetes, the insulin and C-peptide responses to glucose are so low that they may resemble those of early Type I diabetes. The rate of progression of the insulin secretory defect over time does distinguish between these two types of diabetes. In contrast are patients from families who have very high insulin responses to glucose despite glucose intolerance and fasting hyperglycemia similar to those seen in patients with low insulin responses. In many of these patients, there is in vivo and in vitro evidence of insulin resistance. Whatever its mechanism, the compensatory insulin responses to nutrients must be insufficient to maintain normal carbohydrate tolerance. This suggests that diabetes occurs only in those patients who have an additional islet cell defect, i.e., insufficient beta cell reserve and secretory capacity. In a few MODY pedigrees with high insulin responses to glucose and lack of evidence of insulin resistance, an insulin is secreted which is a structurally abnormal, mutant insulin molecule that is biologically ineffective. No associations have been found between specific HLA antigens and MODY in Caucasian, black, and Asian pedigrees. Linkage studies of the insulin gene, the insulin receptor gene, the erythrocyte/Hep G2 glucose transporter locus, and the apolipoprotein B locus have shown no association with MODY. Vascular disease may be as prevalent as in conventional NIDDM. Because of autosomal dominant transmission and penetrance at a young age, MODY is a good model for further investigations of etiologic and pathogenetic factors in NIDDM, including the use of genetic linkage strategies to identify diabetogenic genes.

Severe microvascular disease in type II diabetes of early onset. A family study

Both early onset and late onset type II diabetes were present in one family of nine siblings. The three early onset type II diabetic siblings showed severe microvascular complications: proliferative retinopathy, diabetic nephropathy, and peripheral neuropathy. Early onset type II diabetes was not associated with any particular HLA haplotype. Early onset type II diabetes could be considered a clinical and genetic disease entity different from MODY type diabetes.

Pregnancy outcome in maturity onset diabetes at young age (MODY)

Diabetes mellitus is not a single disease, but rather a syndrome comprised of a variety of diseases characterized by hyperglycaemia. Indeed it has a heterogeneous nature. Maturity Onset Diabetes of the Young or MODY is an unusual, mild type of hyperglycaemia, which develops in young women, (below the age of 25), who do not require insulin. This study describes 10 pregnancies in MODY women, who are compared to a group of patients with insulin-dependent diabetes mellitus (IDDM), a group with gestational diabetes, and a control group of normal, healthy pregnant women. Our group of pregnant MODY patients proved to have an intermediate form of diabetes, more severe than gestational diabetes and yet not as severe as insulin-dependent diabetes mellitus. Mean duration of diabetes was shorter and mean daily insulin requirement (during pregnancy) was lower among MODY patients in comparison to IDDM gestants. Moreover the frequency of maternal complications and Caesarean deliveries in MODY patients were lower than in the IDDM group, but higher when compared to the gestational diabetes group.

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.

Maturity-onset diabetes of youth in black Americans

Twelve of 129 black patients with youth-onset diabetes were identified as having an unusual clinical course, with apparent insulin dependence at the time of presentation followed by absence of dependence months to years later. This atypical form of diabetes was found in at least two generations in 9 of the 12 families of the propositi. Fourteen of the diabetic relatives, as well as the 12 propositi, were studied. Islet-cell autoantibodies were not found in any of the patients, and thyroid microsomal auto-antibodies were found in only one. The frequencies of the insulin-dependent-diabetes-associated antigens HLA-DR3 and DR4 were not increased among the propositi, and diabetes did not cosegregate with HLA haplotypes in the informative families. Insulin secretion, as measured by C-peptide responses to a liquid mixed meal (Sustacal), was intermediate between secretion in nondiabetic controls and that in patients with classic insulin-dependent diabetes. Peripheral-blood monocytes expressed increased numbers of insulin receptors as well as decreased empty-site affinities. The atypical form of diabetes in black Americans can be distinguished from classically defined insulin-dependent diabetes and may be best classified as a form of maturity-onset diabetes of youth.