Effectiveness of screening for diabetes mellitus in dental health care.

AIMS: The aim of the present study was to test the effectiveness of opportunistic blood glucose screening in a cooperational framework between dental and primary health care. METHODS: Altogether, 1568 subjects, age 20-75 years, with no previous history of diabetes, who came for a regular dental examination, had their non-fasting blood glucose measured with a portable blood glucose meter. Subjects with a concentration of ≥ 6.7 mmol/l (121 mg dl(-1) ) were referred to their primary healthcare centre for follow-up. The outcome, a diagnosis of diabetes mellitus, was obtained from primary healthcare centre and hospital patient records, during 3 years after screening. RESULTS: Of the 155 (9.9%) subjects who screened positive, 139 (89.7%) came to their primary healthcare centre within the 3-year follow-up period and nine (5.8%) were diagnosed as having diabetes mellitus according to the World Health Organization criteria. Of the 1413 subjects who screened negative, 1137 (80.5%) came to the primary healthcare centre and eight (0.6%) were found to have diabetes mellitus. Screening sensitivity was 52.9%, specificity 90.6% and positive predictive value 5.8%. The number of subjects needed to screen to find one case of diabetes was 196. Delineating the study population to those 40- to 75-year-olds with a BMI ≥ 25 kg/m(2) , and 30-to 75-year-olds with a BMI ≥ 30 kg/m(2) , the numbers needed to screen was reduced to 96. CONCLUSIONS: Cooperation between dental and primary care for high blood glucose screening and follow-up appears to be a feasible method for early diagnosis of diabetes.

The role of obesity-related genetic loci in insulin sensitivity.

AIMS: Despite rapid advancements and many new diabetes susceptibility loci found in the past few years, few genetic variants associated with insulin sensitivity have been described, potentially attributable to the lack of larger cohorts examined with gold standard methods for insulin sensitivity assessment. There is a strong link between obesity and insulin sensitivity, and we hypothesized that known obesity susceptibility loci may act via effects on insulin sensitivity. METHODS: A cohort of 71-year-old men without diabetes (Uppsala Longitudinal Study of Adult Men) underwent a euglycaemic-hyperinsulinaemic clamp and genotyping for genetic variants representing 32 loci recently reported to be associated with BMI (n = 926). The effect of these loci on the insulin sensitivity index (M/I ratio) was examined using linear regression. An in silico replication was performed in publically available data for the three top single-nucleotide polymorphisms from the Meta-Analyses of Glucose and Insulin-related traits Consortium analyses of homeostasis model assessment of insulin resistance (n = 37,037). RESULTS: Three loci (SH2B1, MTCH2 and NEGR1) were associated with decreased insulin sensitivity at a nominal significance (P ≤ 0.05) after adjustment for BMI, but did not hold for multiple comparison correction. SH2B1 rs7359397 was also associated with homeostasis model assessment of insulin resistance in the Meta-Analyses of Glucose and Insulin-related traits Consortium data set (P = 3.9 × 10(-3)). CONCLUSIONS: Our study supports earlier reports of SH2B1 to be of importance in insulin sensitivity and, in addition, suggests potential roles of NEGR1 and MTCH2.

Organization of trauma management in French level-1 pediatric trauma centers: A cross-sectional survey.

BACKGROUND: Due to the lack of available evidence on pediatric trauma care organization, no French national guideline has been developed. This survey aimed to describe the management of pediatric trauma patients in France. METHODS: In this cross-sectional survey, an electronic questionnaire (previously validated) was distributed to intensive care physicians from tertiary hospitals via the GFRUP (Groupe Francophone de Réanimation et Urgences Pédiatriques) mailing list. RESULTS: We collected 37 responses from 28 centers with available data, representing 100% of French level-1 pediatric trauma centers. Most of the pediatric centers (n = 21, 75%) had a written local protocol on pediatric trauma care. In most centers (n = 17, 61%), patients with severe trauma could be admitted in various locations, including the adult or pediatric emergency department or the intensive care unit. Usually, the location of the trauma room depended on the patients' age and/or severity of trauma. In 12 centers in which trauma could be managed by adult physicians (n = 12/18, 70%), a physician with pediatric expertise (anesthesiologist or intensive care physician) could be called according to the patient's age or severity of trauma. The cut-off patient age for considering pediatric expertise was mainly 3-5 years (n = 10, 83%). CONCLUSION: Although most French level-1 pediatric trauma centers have a local protocol for pediatric trauma management, organization is very heterogeneous in France. Guidelines should focus on collaboration between professionals and hospital facilities in order to improve outcomes of children with trauma.

Diabetes and impaired glucose tolerance in patients with polycystic ovary syndrome--a long term follow-up.

BACKGROUND: The overall risk of developing diabetes mellitus and glucose intolerance seems to be higher in women with polycystic ovary syndrome (PCOS) than in healthy women. The aim of this long-term follow-up study was to examine glucose tolerance and insulin sensitivity in middle-aged women previously diagnosed with PCOS in comparison with age-matched healthy controls. METHODS: Women diagnosed with PCOS between 1987 and 1995 were invited to participate in the study. A total of 84 PCOS patients and 87 control subjects participated. Anthropometric (BMI, waist/hip ratio) and metabolic parameters (oral glucose tolerance test) were measured. Insulin sensitivity was expressed by the Matsuda index and beta cell function by the insulinogenic index. PCOS women were subgrouped according to phenotype at the index assessment (with or without hyperandrogenism) and persistence of PCOS symptoms at the follow-up (persisting or resolved PCOS). RESULTS: Eighteen (21.4%) PCOS patients and four (4.5%) controls had developed type 1 or type 2 diabetes or impaired glucose tolerance (IGT) at the follow-up investigation (P < 0.05). Matsuda insulin sensitivity index was lower and the insulinogenic index was increased in women with previously diagnosed PCOS compared with control subjects. In addition, PCOS patients with or without hyperandrogenism, and PCOS patients with persisting and resolved PCOS all had lower Matsuda insulin sensitivity index and increased insulinogenic index in comparison with controls. CONCLUSIONS: IGT and type 2 diabetes occurred more often in PCOS patients. Independent on PCOS phenotype at index assessment and persistence of PCOS symptoms at the follow-up investigation, women with PCOS had lower insulin sensitivity but a well-preserved beta cell function in comparison with control subjects.

Proinsulin/C-peptide ratio, glucagon and remission in new-onset Type 1 diabetes mellitus in young adults.

AIMS: After initiation of treatment in Type 1 diabetes, a period with lower insulin requirement often follows, reflecting increased insulin sensitivity and improved insulin secretion. We explored if efficiency of proinsulin processing is associated with the remission phenomenon. METHODS: Seventy-eight patients with new-onset Type 1 diabetes were followed prospectively for 3 years. Daily insulin dosage, HbA(1c) , plasma glucose, proinsulin, C-peptide, glucagon concentrations and islet antibodies were determined at diagnosis and after 3, 6, 9, 12, 18, 24, 30 and 36 months. We studied remission, defined as an insulin dose ≤ 0.3 U kg(-1) 24 h(-1) and HbA(1c) within the normal range, in relation to the above-mentioned variables. RESULTS: A rise and subsequent decline in plasma proinsulin and C-peptide concentrations was observed. Forty-five per cent of the patients experienced remission at one or more times, characterized by higher proinsulin and C-peptide levels, and lower proinsulin/C-peptide ratios, indicating more efficient proinsulin processing, compared with those not in remission. Non-remission also tended to be associated with higher glucagon values. Patients entering remission were more often men, had higher BMI at diagnosis, but did not differ at baseline with respect to islet antibody titres compared with patients with no remission. CONCLUSIONS: Remissions after diagnosis of Type 1 diabetes were associated with lower proinsulin/C-peptide ratios, suggesting more efficient proinsulin processing, and tended to have lower glucagon release than non-remissions. This indicates that, in remission, the residual islets maintain a secretion of insulin and glucagon of benefit for control of hepatic glucose production.

Plasma levels of glucagon like peptide-1 associate with diastolic function in elderly men.

AIMS: Congestive heart failure is a major cause of morbidity and mortality in diabetes. Besides the glycaemic effects of glucagon-like peptide 1 (GLP-1) mimetics, their effects on the heart are of interest. METHODS: We aimed to investigate longitudinal relationships between plasma levels of fasting GLP-1 (fGLP-1), 60-min oral glucose tolerance test-stimulated GLP-1 levels (60GLP-1), and the dynamic GLP-1 response after oral glucose tolerance test (ΔGLP-1 = 60GLP-1 - fGLP-1) and incidence of hospitalized congestive heart failure, during a follow-up time of a maximum of 9.8 years in 71-year-old men. We also investigated, cross-sectionally, the association between GLP-1 and left ventricular function as estimated by echocardiography. R: During the follow-up period, 16 of 290 participants with normal glucose tolerance experienced a congestive heart failure event (rate 0.7/100 person-years at risk), as did eight of 136 participants (rate 0.8/100 person-years at risk) with impaired glucose tolerance and nine of 72 participants (rate 1.7/100 person-years at risk) with Type 2 diabetes mellitus. Although GLP-1 concentrations did not predict congestive heart failure (fGLP-1: HR 0.98, 95% CI 0.4-2.4; 60GLP-1: HR 1.1, 95% CI 0.4-2.6; ΔGLP-1: HR 0.9, 95% CI 0.3-2.3), there was an association between left ventricular diastolic function (E/A ratio) and fGLP-1 (r = 0.19, P = 0.001), 60GLP-1 (r = 0.20, P < 0.001) and ΔGLP-1 (r = 0.18, P = 0.004). There was a lack of differences in plasma levels of GLP-1 between the groups with Type 2 diabetes and normal glucose tolerance. CONCLUSIONS: There were no longitudinal associations between GLP-1 levels and incidence of hospitalization for congestive heart failure. However, without any causality proven, GLP-1 levels did correlate, cross-sectionally, with left ventricular diastolic function in this cohort, suggesting that pathways including GLP-1 might be involved in the regulation of cardiac diastolic function.

Reduced plasma levels of glucagon-like peptide-1 in elderly men are associated with impaired glucose tolerance but not with coronary heart disease.

AIMS/HYPOTHESIS: Besides the insulinotropic effects of glucagon-like peptide-1 (GLP-1) mimetics, their effects on endothelial dysfunction and myocardial ischaemia are of interest. No previous study has investigated associations between plasma levels of GLP-1 and CHD. METHODS: We investigated longitudinal relationships of fasting GLP-1 with the dynamic GLP-1 response after OGTT (difference between 60 min OGTT-stimulated and fasting GLP-1 levels [DeltaGLP-1]) and CHD in a population-based cohort of 71-year-old men. In the same cohort, we also cross-sectionally investigated the association between stimulated GLP-1 levels and: (1) cardiovascular risk factors (blood pressure, lipids, urinary albumin, waist circumference and insulin sensitivity index [M/I] assessed by euglycaemic-hyperinsulinaemic clamp); and (2) impaired glucose tolerance (IGT) and type 2 diabetes mellitus. RESULTS: During the follow-up period (maximum 13.8 years), of 294 participants with normal glucose tolerance (NGT), 69 experienced a CHD event (13.8 years), as did 42 of 141 with IGT and 32 of 74 with type 2 diabetes mellitus. DeltaGLP-1 did not predict CHD (HR 1.0, 95% CI 0.52-2.28). The prevalence of IGT was associated with DeltaGLP-1, lowest vs highest quartile (OR 0.3, 95% CI 0.12-0.58), with no such association for type 2 diabetes mellitus (OR 1.0, 95% CI 0.38-2.86). M/I was significantly associated with DeltaGLP-1 in the type 2 diabetes mellitus group (r = 0.38, p < 0.01), but not in the IGT (r = 0.11, p = 0.28) or NGT (r = 0.10, p = 0.16) groups. CONCLUSIONS/INTERPRETATION: Impaired GLP-1 secretion is associated with IGT, but not with type 2 diabetes mellitus. This finding in the latter group might be confounded by oral glucose-lowering treatment. GLP-1 does not predict CHD. Although DeltaGLP-1 was associated with insulin sensitivity in the type 2 diabetes mellitus group, GLP-1 does not seem to be a predictor of CHD in insulin-resistant patients.

Serum and dietary beta-carotene and alpha-tocopherol and incidence of type 2 diabetes mellitus in a community-based study of Swedish men: report from the Uppsala Longitudinal Study of Adult Men (ULSAM) study.

AIMS/HYPOTHESIS: To investigate the association of serum concentrations and dietary intake of beta-carotene and alpha-tocopherol with type 2 diabetes incidence. METHODS: Serum beta-carotene, alpha-tocopherol, lifestyle factors (BMI, physical activity and smoking) and metabolic factors (insulin sensitivity [homeostasis model assessment], acute insulin response and impaired fasting glucose) were analysed in 846 50-year-old non-diabetic Swedish men (participants in the Uppsala Longitudinal Study of Adult Men). Diabetes was identified in 245 participants at reinvestigations after 10, 20 and 27 years. At the 20 year reinvestigation, dietary intake of beta-carotene and alpha-tocopherol, insulin sensitivity (euglycaemic-hyperinsulinaemic clamp) and insulin secretion (early insulin response in OGTT) were determined. RESULTS: The highest tertile of serum beta-carotene at age 50 (>0.335 mumol/l) was associated with 59% lower risk of diabetes during follow-up compared with the lowest tertile (<0.210 mumol/l) after adjustment for lifestyle and metabolic factors (p < 0.01). The highest tertile of lipid-corrected serum alpha-tocopherol at age 50 (>3.67 mumol/mmol) was associated with 46% lower risk of diabetes compared with the lowest tertile (<3.25 mumol/mmol) independently of metabolic factors (p < 0.05). Moreover, lower serum beta-carotene and alpha-tocopherol concentrations were independently associated with impaired insulin sensitivity (p < 0.001), but not with early insulin response, in a subsample of non-diabetic individuals 20 years later. Dietary intake of beta-carotene and alpha-tocopherol independently predicted type 2 diabetes during 7 years of follow-up. CONCLUSIONS/INTERPRETATION: Serum concentrations and dietary intakes of beta-carotene and alpha-tocopherol independently predicted insulin resistance and type 2 diabetes incidence during 27 years of follow-up in a community-based study of men. This result supports the importance of impaired antioxidant status for the development of insulin resistance and type 2 diabetes.

Glucose metabolism and the risk of Alzheimer's disease and dementia: a population-based 12 year follow-up study in 71-year-old men.

AIMS/HYPOTHESIS: Accumulating evidence suggests that diabetes increases the risk of dementia, but few studies have addressed possible mechanisms underlying this relationship. The aim of our study was to investigate the longitudinal association of glucose metabolism, insulin secretion and insulin action with the development of Alzheimer's disease and vascular dementia. METHODS: The Uppsala Longitudinal Study of Adult Men is an ongoing observational study in Sweden in which 1,125 men aged 71 years and free from dementia underwent an OGTT and a euglycaemic insulin clamp between 1990 and 1995. During a median follow-up of 12 years, 257 persons developed dementia or cognitive impairment, of whom 81 had Alzheimer's disease and 26 vascular dementia. Associations were analysed with the Cox proportional hazards method. RESULTS: Low early insulin response to oral glucose challenge, but not low insulin sensitivity, was associated with a higher risk of Alzheimer's disease (HR for 1 SD decrease 1.32; 95% CI 1.02, 1.69) after adjustment for diabetes, blood pressure, body mass index, cholesterol, smoking and educational level. Low insulin sensitivity was associated with a higher risk of vascular dementia (HR for 1 SD decrease 1.55; 95% CI 1.02, 2.35), but not after multiple adjustments. Diabetes increased the risk of any dementia and cognitive impairment by 63%. CONCLUSIONS/INTERPRETATION: In this community-based study, low early insulin response was associated with increased risk of subsequent Alzheimer's disease, whereas low insulin sensitivity was not. Vascular dementia was not related to early insulin response. We suggest that glucometabolic disturbances are linked differentially to the pathogenesis of these two main dementia subtypes.

Obstructive sleep apnoea is associated with decreased insulin sensitivity in females.

The aim of the present study was to assess associations between obstructive sleep apnoea and insulin sensitivity in a population-based sample of females. In total, 400 females aged 20-70 yrs underwent a full-night polysomnography, fasting blood sampling, measurement of anthropometric variables and oral glucose tolerance test with measurement of the insulin response (n = 358). The apnoea/hypopnoea index (AHI) was calculated from the results of the polysomnography. From the results of the oral glucose tolerance test, an insulin sensitivity index (ISI) was calculated. Females with an AHI < 5 (n = 119) had a mean+/-SD ISI of 8.3+/-3.8, whereas females with an AHI > or = 30 (n = 34) had an ISI of 6.2+/-4.0. Nocturnal minimal saturation was independently associated with decreased insulin sensitivity when controlling for age, waist/hip ratio, level of physical activity, smoking and alcohol consumption (95% confidence interval (CI) 0.004-0.14). When adjusting for confounders, the AHI was associated with increased fasting and 2-h insulin levels (95% CI 0.14-0.99 and 95% CI 0.28-6.47, respectively). Obstructive sleep apnoea was found to be independently associated with decreased insulin sensitivity in the present population-based sample of females.

Sympathetic response to oral carbohydrate administration. Evidence from microelectrode nerve recordings.

Microneurography was used to measure sympathetic outflow in human muscle nerves (MSA) for up to 90 min after the ingestion of 100 g D-glucose, 75.8 g D-xylose, intravenous D-glucose (0.35 g/kg), and 300 ml water. 19 healthy subjects were examined using a microelectrode positioned in the right peroneal nerve. MSA increased from 21 +/- 0.9 bursts/min at rest to 36.9 +/- 4.3 bursts/min 30 min after ingestion of D-glucose and from 18.9 +/- 2.9 to 26.3 +/- 3.4 bursts/min 30 min after D-xylose. The increase in MSA was already significant by 15 min. MSA had not returned to the basal level after 90 min. Neither intravenous D-glucose nor water intake enhanced MSA. MSA increased in parallel with plasma norepinephrine, and a significant correlation (r = 0.55; P less than 0.001) was observed between the plasma insulin concentration and MSA after D-glucose ingestion. In three subjects the outflow of sympathetic nerve activity to the skin was examined after oral D-glucose and no change was observed, emphasizing the differentiated nature of the sympathetic nerve response to carbohydrate. Multiple factors such as insulin alone, hemodynamic adjustment to splanchnic vasodilation, and gastrointestinal distension are probably involved in the increased muscle nerve sympathetic outflow after carbohydrate ingestion.

The influence of glucose self-monitoring on glycaemic control in patients with diabetes mellitus in Sudan.

OBJECTIVE: To investigate the influence of self-monitoring of glucose on the glycaemic control in Sudanese diabetic subjects. SUBJECTS AND METHODS: A group of 193 consecutive type 2 and type 1 diabetic subjects (95 men, 98 women) were studied. In 104 subjects with type 2 diabetes fasting blood glucose was measured using a glucose meter and blood was obtained for serum glucose measurement in the laboratory. In the remaining 89 diabetic subjects random blood glucose was measured using the same glucose meter and a whole blood sample was drawn for laboratory assessment of HbA1c. Data on self-monitoring and other clinical and personal characteristics were recorded. RESULTS: More than 75% of either type 1 and type 2 diabetic patients never self-monitored blood or urine glucose. In type 2 diabetic subjects self-monitoring of blood or urine glucose was not related to glycaemic control. In type 1 diabetic subjects, however, self-monitoring of blood glucose was significantly associated with better glycaemic control, as assessed by HbA1c (P=0.02) and blood glucose at clinic visits (P< or =0.0001), and similar associations were found for urine glucose self-monitoring (P=0.04 and 0.02) respectively. Neither glycaemic control nor glucose self-monitoring was associated with education level. CONCLUSIONS: Self-monitoring of blood glucose was not found to be associated to better glycaemic control in Sudanese subjects with type 2 diabetes. In contrast, self-monitoring of both blood and urine glucose was significantly associated with glycaemic control in subjects with type 1 diabetes. Self-monitoring of urine glucose could be useful where measurement of blood glucose is not available or affordable.

Excess risk of primary liver cancer in patients with diabetes mellitus.

BACKGROUND: Chronic infection with hepatitis B virus, alcohol consumption, and cirrhosis of the liver are recognized risk factors for primary liver cancer. A few, but not all, studies have suggested that diabetes mellitus also increases risk for this cancer. PURPOSE: We conducted a population-based cohort study to analyze the risk of developing primary liver cancer and biliary tract (gallbladder, extrahepatic bile ducts, and ampulla of Vater) cancers among patients with diabetes. METHODS: A cohort of 153 852 patients with a hospital discharge diagnosis of diabetes in the period from 1965 through 1983 was identified by use of the Swedish In-patient Register. Follow-up for these patients extended from the date of cohort entry through December 31, 1989. Incident cases of cancer during follow-up were identified through the Swedish Cancer Registry. To minimize the impact of selection bias, we excluded from the analysis patients who were diagnosed with liver and biliary tract cancers during the first year of follow-up. Standardized incidence ratios (SIRs) and their 95% confidence intervals (CIs) were computed by use of nationwide rates of liver and biliary tract cancers, adjusted for age, sex, and calendar year, for comparison. RESULTS: During 1-24 years of follow-up, 819 incident cancers in the combined category of primary liver (n = 533) and biliary tract (n = 286) were identified in the cohort, yielding an overall SIR of 2.5 (95% CI = 2.3-2.6). The risk was higher in men (SIR = 3.2; 95% CI = 2.9-3.6) than in women (SIR = 2.0; 95% CI = 1.8-2.2). The incidence of primary liver cancer alone was increased fourfold (SIR = 4.1; 95% CI = 3.8-4.5); again, the risk was higher in men (SIR = 4.7; 95% CI = 4.2-5.2) than in women (SIR = 3.4; 95% CI = 2.9-3.9). Smaller increases in risk were seen for cancers of the gallbladder, the extrahepatic bile ducts, and the ampulla of Vater. After exclusion of diabetic patients with concomitant diseases that predispose to primary liver cancer, such as alcoholism, cirrhosis, and hepatitis, the persistence of an approximately threefold excess risk was observed. CONCLUSIONS: Our findings suggest that patients with diabetes are at increased risk of developing primary liver cancer and perhaps cancers of the biliary tract. The mechanisms involved in the association of diabetes and liver cancer remain to be clarified. Additional studies are needed to determine whether patients with insulin-dependent diabetes mellitus and those with non-insulin-dependent diabetes mellitus differ in their risk for primary liver cancer or whether the risk is affected by the type of diabetes treatment.

Sympathetic outflow in human muscle nerves increases during hypoglycemia.

The normal response to insulin-induced hypoglycemia bears many characteristics of activation of the sympathetic nervous system. In this study, the impulse pattern of muscle nerve sympathetic activity (MSA) involved in cardiovascular homeostasis was identified by microneurography in the peroneal nerve of seven healthy and two adrenalectomized subjects. After recordings at rest and an intravenous injection of 0.15 IU insulin/kg body wt (0.10 IU insulin/kg body wt in adrenalectomized subjects), MSA was followed for 90 min. Nadir of hypoglycemia (2.0 +/- 0.1 mM) was reached at 30 min. All subjects, including the two adrenalectomized subjects, exhibited an increase of MSA, which peaked at the glucose nadir. The time course of MSA increase was a mirror image of the blood glucose curve. This directly measured increase of MSA may be part of the hemodynamic adjustment to the fall in plasma volume known to occur in hypoglycemia. Another possible cause is direct stimulation of central sympathetic motoneurons.

Diazoxide treatment at onset preserves residual insulin secretion in adults with autoimmune diabetes.

Twenty islet cell antibody (ICA)-positive patients, aged 19-38 years, with IDDM were randomized at onset to treatment with either diazoxide, a K+ channel opener that inhibits the release of insulin, or placebo for 3 months, in addition to multiple insulin injection therapy. The patients who were given diazoxide displayed higher residual insulin secretion than the placebo group after 1 year (basal C-peptide level, 0.40 +/- 0.04 vs. 0.25 +/- 0.04 [mean +/- SE] nmol/l; P < 0.021) and at an 18-month follow-up (0.37 +/- 0.06 vs. 0.20 +/- 0.01 nmol/l, P < 0.033). Metabolic control did not differ between the two groups. During the course of the study, no differences in islet cell or GAD autoantibodies were detected between the two groups. The results of this study warrant further trials to explore the potential of inducing target cell rest in order to halt the loss of insulin-producing cells during the early course of the disease.

In vitro and in vivo studies of a naturally occurring variant of the human p85alpha regulatory subunit of the phosphoinositide 3-kinase: inhibition of protein kinase B and relationships with type 2 diabetes, insulin secretion, glucose disappearance constant, and insulin sensitivity.

In humans, the Met326Ile missense variant of the p85alpha regulatory subunit of the phosphoinositide 3-kinase (PI3K) has been associated with either significant reductions in glucose effectiveness and intravenous glucose tolerance in Caucasians or a significantly higher insulin secretory response in Pima Indians. In the present study, we genotyped 1,190 Caucasian males to evaluate the impact in vivo of the Met326Ile variant of the p85alpha subunit of PI3K on the acute insulin response, intravenous glucose tolerance, insulin-mediated glucose uptake, and the prevalence of type 2 diabetes after 20 years of follow-up. We also expressed the variant in vitro to evaluate the impact on insulin-stimulated activation of protein kinase B (PKB). The Met326Ile variant of p85alpha was not associated with type 2 diabetes or with alterations in insulin secretion, insulin sensitivity, or intravenous glucose tolerance in vivo. Expressed in vitro, the Ile326 and the Met326 variant acted equally as a dominant-negative and prevented (60-70% inhibition) insulin-mediated activation of PKB by inhibiting the phosphorylation of PKB at Thr308. We conclude that the Met326Ile variant of the p85alpha regulatory subunit of PI3K is likely to be as functionally normal in vivo as in vitro.

Current status of clinical islet transplantation.

Islet transplantation is currently being explored as a treatment for patients with type 1 diabetes. At present, the number of patients becoming insulin-independent is rapidly increasing world-wide applying the transplantation protocol originally described by the group in Edmonton. A hallmark in this procedure is repeated infusions of islets obtained from 2 to 4 donors until normoglycemia is achieved. In order to establish islet transplantation as a widely accepted treatment modality, and make tolerance induction regimes applicable, it is essential that the donor:recipient ratio is brought down to 1:1. A conceivable strategy to achieve this goal in clinical islet transplantation is discussed.

How accurate are insulin mixtures prepared by the patient?

The accuracy of mixing two types of insulin in one syringe was studied in 41 insulin-dependent diabetic patients who prepared a mixture of two fluids (saline and sterile water) with either a disposable, 1-ml plastic syringe with a fixed needle, i.e., with a small dead space, or one equipped with a separate needle. Syringes with fixed needles delivered the two components very accurately and were associated with only slight wastage of insulin of 0.011 ml per injection. The syringe with a separate needle delivered 0.033-0.065 ml more than the intended dose of the "first insulin" and correspondingly less of the intended dose of the "second insulin," since the total dose delivered was approximately correct. The magnitude of the insulin wastage of two daily injections was calculated to be 64 ml per patient annually, which could be reduced to 8 ml per patient if fixed needles were used. It is therefore recommended that patients preparing mixtures of two insulins in the same syringe abandon syringes with separate needles.

Effects of antihypertensive treatment on insulin sensitivity with special reference to ACE inhibitors.

In 1984, the suspicion that pharmacological treatment may worsen the insulin resistance and associated metabolic abnormalities in lipid and carbohydrate metabolism and contribute to the relative failure of antihypertensive treatment to produce more than marginal reductions in cardiovascular morbidity and mortality led us to start a series of trials aimed at elucidating how antihypertensive drugs affect insulin sensitivity. These trials, which included assessment of insulin sensitivity by the euglycemic insulin clamp, showed that beta-adrenergic blockade and thiazide diuretic treatment (hydrochlorothiazide) increase insulin resistance and basal plasma insulin, whereas Ca(2+)-channel antagonists (verapamil and diltiazem), with the exception of the negative effect of nifedipine, are metabolically neutral. alpha-Adrenergic blockade with prazosin and angiotensin-converting enzyme (ACE) inhibition with captopril enhance insulin sensitivity. The mechanisms underlying the positive effects of ACE inhibition and beta-adrenergic blockade are largely unknown, but hemodynamic factors (vasodilation) may contribute by improving the access of glucose and insulin to skeletal muscle. The drugs, which were favorable or neutral with respect to insulin sensitivity, caused no changes in lipids or glucose homeostasis. In contrast, beta-blockers, except pindolol, had negative effects on triglycerides and high-density lipoprotein cholesterol, and thiazide diuretics caused adverse effects on total serum cholesterol, low-density lipoprotein cholesterol, and total and very-low-density lipoprotein triglyceride. The metabolic action of antihypertensive drugs is an important factor to consider in the choice of a proper treatment strategy in both diabetic and nondiabetic patients with hypertension.

Lack of cutaneous hyperemia in response to insulin-induced hypoglycemia in IDDM.

Cutaneous blood flow was measured with the laser Doppler technique and by recording cutaneous O2 tension on the forearm and forehead in nine young adult patients with insulin-dependent diabetes mellitus (IDDM) and nine sex- and age-matched healthy control subjects after induction of hypoglycemia. In the healthy subjects, cutaneous blood flow measured with the laser Doppler technique was increased by 120 +/- 26% in the forehead (P less than 0.01) and 196 +/- 50% in the forearm (P less than 0.01) at the glucose nadir (blood glucose 1.8 +/- 0.2 mM) compared with basal blood flow. In contrast, in diabetic patients, cutaneous blood flow was unchanged. The corresponding changes, at the glucose nadir, with cutaneous O2 tension recordings were 286 +/- 131% (P less than 0.05) in control subjects and -22 +/- 15% (NS) in diabetic patients. An impairment of sympathetic nervous function, not detectable by simple cardiovascular tests, could be responsible for the lack of cutaneous hyperemia and sweating and could contribute to unawareness of hypoglycemia in diabetic patients.