Heterogeneity in young adult onset diabetes: aetiology alters clinical characteristics.

AIMS: To describe the characteristics of hepatocyte nuclear factor (HNF) 1 alpha mutation carriers diagnosed with diabetes after 25 years and compare them with young-onset Type 2 diabetic patients (YT2D) diagnosed at the same age. SUBJECTS AND METHODS: We studied 44 (21 male, 23 female) patients with HNF-1 alpha mutations diagnosed with diabetes at ages 25-45 years and 44 YT2D subjects matched for sex and age of diagnosis. RESULTS: Median age of onset of diabetes was 35 years in both groups. The HNF-1 alpha group demonstrated: lower body mass index (25.1 vs. 30.7 kg/m2; P < 0.001) and lower fasting triglycerides (1.37 vs. 2.96 mmol/l; P = 0.001) with similar fasting cholesterol level. They had lower glycated haemoglobin A1c (7.3 vs. 8.5%; P = 0.015) despite greater duration of diabetes (24 vs. 16 years; P = 0.02) and less frequent treatment with insulin (21% vs. 55%; P = 0.002). They were less likely to be treated for hypertension (13.3% vs. 56.3%; P = 0.009). Importantly, no difference was observed in reported parental history of diabetes between the two groups (65.9% vs. 63.6%; P = 0.92). Logistic regression showed that triglyceride levels and presence of anti-hypertensive treatment were the most important independent variables. CONCLUSIONS: Patients with HNF-1 alpha mutations may present with diabetes as young adults between the ages of 25-45 years. In this age range a wide differential diagnosis of diabetes is observed. Conventional criteria of age of onset and family history will not differentiate HNF-1 alpha mutation carriers from YT2D subjects in this age range, but features of the metabolic syndrome, in particular fasting triglycerides and hypertension, are helpful. In patients diagnosed before 45 years without features of insulin resistance the diagnosis of HNF-1 alpha should be considered.     

An approach to evaluating the drug and alcohol problem in prisoners

In this paper a perspective on the drug and alcohol problems experienced in a specific group, namely, prisoners, is offered. The roles of the medical profession as assessors of drug and alcohol problems, and as educators, is briefly discussed.     

Beta-cell dysfunction, insulin sensitivity, and glycosuria precede diabetes in hepatocyte nuclear factor-1alpha mutation carriers

OBJECTIVE: Patients with diabetes due to hepatocyte nuclear factor (HNF)-1alpha mutations have beta-cell deficiency, insulin sensitivity, altered proinsulin levels, and a low renal threshold for glucose. It is uncertain how many of these features precede the development of diabetes. The aim of our study was to test for these characteristics in young nondiabetic HNF-1alpha mutation carriers. RESEARCH DESIGN AND METHODS: A total of 47 offspring from 19 extended families underwent genetic testing, a standard oral glucose tolerance test, and urine testing. RESULTS: HNF-1alpha mutations were found in 20 offspring, 7 with diabetes and 13 without diabetes. The 13 nondiabetic mutation carriers were compared with 27 family control subjects, who were matched for age, sex, and BMI. There was marked beta-cell deficiency with reduced insulinogenic index (53.5 [31.5-90.9] vs. 226.0 [126.0-407.1], SD [range], P < 0.001) and area under the curve for insulin (P < 0.001). Insulin sensitivity was increased in mutation carriers (homeostatic model assessment of insulin sensitivity 144.6 [82.7-252.7] vs. 100 [66.9-149.4], P = 0.025). A total of 38% of mutation carriers had glycosuria at 2 h compared with 0% of control subjects (P = 0.0034). Those with glycosuria had peak glucose values that were higher than the mutations carriers without glycosuria (range 8.1-11.8 vs. 6.2-8.4 mmol/l, P = 0.002). The seven subjects with diabetes all showed glycosuria. CONCLUSIONS: We conclude that marked beta-cell deficiency, increased insulin sensitivity, and a low renal threshold are present in young nondiabetic HNF-1alpha mutation carriers. The presence of glycosuria post-glucose load could be used to screen children of mutation carriers as it occurs in all mutation carriers with a peak glucose in the oral glucose tolerance test >8.4 mmol/l.     

Long-term transgene expression by administration of a lentivirus-based vector to the fetal circulation of immuno-competent mice

Inefficient gene transfer, inaccessibility of stem cell compartments, transient gene expression, and adverse immune and inflammatory reactions to vector and transgenic protein are major barriers to successful in vivo application of gene therapy for most genetic diseases. Prenatal gene therapy with integrating vectors may overcome these problems and prevent early irreparable organ damage. To this end, high-dose attenuated VSV-G pseudotyped equine infectious anaemia virus (EIAV) encoding beta-galactosidase under the CMV promoter was injected into the fetal circulation of immuno-competent MF1 mice. We saw prolonged, extensive gene expression in the liver, heart, brain and muscle, and to a lesser extent in the kidney and lung of postnatal mice. Progressive clustered hepatocyte staining suggests clonal expansion of cells stably transduced. We thus provide proof of principle for efficient gene delivery and persistent transgene expression after prenatal application of the EIAV vector and its potential for permanent correction of genetic diseases.     

Mutations in ATP-sensitive K+ channel genes cause transient neonatal diabetes and permanent diabetes in childhood or adulthood

Transient neonatal diabetes mellitus (TNDM) is diagnosed in the first 6 months of life, with remission in infancy or early childhood. For approximately 50% of patients, their diabetes will relapse in later life. The majority of cases result from anomalies of the imprinted region on chromosome 6q24, and 14 patients with ATP-sensitive K+ channel (K(ATP) channel) gene mutations have been reported. We determined the 6q24 status in 97 patients with TNDM. In patients in whom no abnormality was identified, the KCNJ11 gene and/or ABCC8 gene, which encode the Kir6.2 and SUR1 subunits of the pancreatic beta-cell K(ATP) channel, were sequenced. K(ATP) channel mutations were found in 25 of 97 (26%) TNDM probands (12 KCNJ11 and 13 ABCC8), while 69 of 97 (71%) had chromosome 6q24 abnormalities. The phenotype associated with KCNJ11 and ABCC8 mutations was similar but markedly different from 6q24 patients who had a lower birth weight and who were diagnosed and remitted earlier (all P < 0.001). K(ATP) channel mutations were identified in 26 additional family members, 17 of whom had diabetes. Of 42 diabetic patients, 91% diagnosed before 6 months remitted, but those diagnosed after 6 months had permanent diabetes (P < 0.0001). K(ATP) channel mutations account for 89% of patients with non-6q24 TNDM and result in a discrete clinical subtype that includes biphasic diabetes that can be treated with sulfonylureas. Remitting neonatal diabetes was observed in two of three mutation carriers, and permanent diabetes occurred after 6 months of age in subjects without an initial diagnosis of neonatal diabetes.