Graziella Bruno

Comment on:Management of Hyperglycemia in Type 2 Diabetes: APatient-Centered Approach. Position Statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

Glycemic management in type 2 diabetes mellitus has become increasingly complex and, to some extent, controversial, with a widening array of pharmacological agents now available (1–5), mounting concerns about their potential adverse effects and new uncertainties regarding the benefits of intensive glycemic control on macrovascular complications (6–9). Many clinicians are therefore perplexed as to the optimal strategies for their patients. As a consequence, the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) convened a joint task force to examine the evidence and develop recommendations for antihyperglycemic therapy in nonpregnant adults with type 2 diabetes. Several guideline documents have been developed by members of these two organizations (10) and by other societies and federations (2,11–15). However, an update was deemed necessary because of contemporary information on the benefits/risks of glycemic control, recent evidence concerning efficacy and safety of several new drug classes (16,17), the withdrawal/restriction of others, and increasing calls for a move toward more patient-centered care (18,19). This statement has been written incorporating the best available evidence and, where solid support does not exist, using the experience and insight of the writing group, incorporating an extensive review by additional experts (acknowledged below). The document refers to glycemic control; yet this clearly needs to be pursued within a multifactorial risk reduction framework. This stems from the fact that patients with type 2 diabetes are at increased risk of cardiovascular morbidity and mortality; the aggressive management of cardiovascular …

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3–19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8–144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries. DOI: http://dx.doi.org/10.7554/eLife.13410.001

CD8+ T-Cell Responses Identify β-Cell Autoimmunity in Human Type 1 Diabetes

Despite the understanding that type 1 diabetes pathogenesis is mediated by T-cells, detection of these rare lymphocytes remains largely elusive. Suitable T-cell assays are highly needed, since they could offer preclinical diagnoses and immune surrogate end points for clinical trials. Although CD4+ T-cell assays have met with limited success, CD8+ T-cells are increasingly recognized as key actors in the diabetes of the NOD mouse. CD8+ T-cells are likely to play a role also in humans and may provide new markers of β-cell autoimmunity. Taking advantage of a panel of HLA-A2–restricted β-cell epitopes derived from preproinsulin, GAD, and islet glucose-6-phosphatase catalytic subunit-related protein (IGRP), we have implemented an islet-specific CD8+ T-cell interferon-γ enzyme-linked immunospot (ISL8Spot) assay. The ISL8Spot assay is capable of detecting and quantifying β-cell–reactive CD8+ T-cells directly ex vivo, without any preliminary expansion, using either fresh or frozen samples. Positive ISL8Spot responses separate new-onset diabetic and healthy samples with high accuracy (86% sensitivity, 91% specificity), using as few as five immunodominant epitopes. Moreover, sensitivity reaches 100% when the ISL8Spot assay is complemented by antibody determinations. Combination of CD8+ T-cell measurements with immune intervention strategies may open new avenues toward type 1 diabetes prediction and prevention.

Urinary Exosomal MicroRNAs in Incipient Diabetic Nephropathy

MicroRNAs (miRNAs), a class of small non-protein-encoding RNAs, regulate gene expression via suppression of target mRNAs. MiRNAs are present in body fluids in a remarkable stable form as packaged in microvesicles of endocytic origin, named exosomes. In the present study, we have assessed miRNA expression in urinary exosomes from type 1 diabetic patients with and without incipient diabetic nephropathy. Results showed that miR-130a and miR-145 were enriched, while miR-155 and miR-424 reduced in urinary exosomes from patients with microalbuminuria. Similarly, in an animal model of early experimental diabetic nephropathy, urinary exosomal miR-145 levels were increased and this was paralleled by miR-145 overexpression within the glomeruli. Exposure of cultured mesangial cells to high glucose increased miR-145 content in both mesangial cells and mesangial cells-derived exosomes, providing a potential mechanism for diabetes-induced miR-145 overexpression. In conclusion, urinary exosomal miRNA content is altered in type 1 diabetic patients with incipient diabetic nephropathy and miR-145 may represent a novel candidate biomarker/player in the complication.

Counting diabetes in the next millennium. Application of capture-recapture technology.

Monitoring diabetes is critical for our understanding of the etiology and natural history of disease and for public health actions. However, traditional methods for monitoring are either too expensive (e.g., IDDM registries, NIDDM-OGTT prevalence surveys) or too inaccurate (routinely collected data or passive surveillance) for broad accurate, national programs for monitoring the incidence and prevalence of disease. We suggest that one technology called capture-recapture would considerably increase our ability to “count” diabetes, both nationally and globally. Implementation of this approach could lead to accurate inter- and intracountry data on rates of disease. Moreover, such tracking of diabetes could serve as the model for the monitoring of all disease in the 21st century and beyond.

Prevalence and Risk Factors for Micro- and Macroalbuminuria in an Italian Population-Based Cohort of NIDDM Subjects

OBJECTIVE To determine the prevalence of micro- and macroalbuminuria in NIDDM and their relationship with some known and putative risk factors. RESEARCH DESIGN AND METHODS Out of a population-based cohort of 1,967 NIDDM subjects, 1,574 were investigated (80%). Albumin excretion rate (AER) was evaluated on an overnight urine collection, and plasma and urine determinations were centralized. RESULTS The prevalences of microalbuminuria (AER 20–200 μg/min), macroalbuminuria (AER > 200 μg/min), and hypertension were 32.1% (95% CI 29.8–34.4), 17.6% (15.7–19.5), and 67% (64.6–69.3), respectively. Apart from prevalence of hypertension, which after adjustment for age, BMI, and duration of diabetes was 2.3 times higher in women, rates were higher in men (odds ratio [OR] 1.31, 95% CI 1.04–1.66 for microalbuminuria and OR 1.63, 1.22–2.17 for macroalbuminuria). In comparison with normoalbuminuric subjects, both micro- and macroalbuminuric diabetic subjects had significantly longer duration of diabetes, higher levels of systolic blood pressure, fasting plasma glucose, HbA1c, triglycerides, and uric acid; in macroalbuminuric subjects only, levels of apolipoprotein B and HDL cholesterol were, respectively, higher and lower than in normo- and microalbuminuric subjects. In logistic regression, variables independently related to both micro- and macroalbuminuria were age, HbA1c, cigarette smoking habits, plasma uric acid, and diastolic blood pressure, after adjustment for plasma creatinine and diabetic treatment. In addition, duration of diabetes and HDL cholesterol levels were associated with macroalbuminuria. CONCLUSIONS This population-based study showed high prevalence of micro- and macroalbuminuria in NIDDM subjects, who were characterized by a more adverse pattern of cardiovascular risk factors.

The Frequency and Immunodominance of Islet-specific CD8+ T-cell Responses Change after Type 1 Diabetes Diagnosis and Treatment

OBJECTIVE—Islet-reactive CD8+ T-cells play a key role in the pathogenesis of type 1 diabetes in the NOD mouse. The predominant T-cell specificities change over time, but whether similar shifts also occur after clinical diagnosis and insulin treatment in type 1 diabetic patients is unknown. RESEARCH DESIGN AND METHODS—We took advantage of a recently validated islet-specific CD8+ T-cell γ-interferon enzyme-linked immunospot (ISL8Spot) assay to follow responses against preproinsulin (PPI), GAD, insulinoma-associated protein 2 (IA-2), and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) epitopes in 15 HLA-A2+ adult type 1 diabetic patients close to diagnosis and at a second time point 7–16 months later. RESULTS—CD8+ T-cell reactivities were less frequent at follow-up, as 28.6% of responses tested positive at type 1 diabetes diagnosis vs. 13.2% after a median of 11 months (P = 0.003). While GAD and IA-2 autoantibody (aAb) titers were unchanged in 75% of cases, the fraction of patients responding to PPI and/or GAD epitopes by ISL8Spot decreased from 60–67 to 20% (P < 0.02). The previously subdominant IA-2206–214 and IGRP265–273 peptides were newly targeted, thus becoming the immunodominant epitopes. CONCLUSIONS—Shifts both in frequency and in immunodominance of CD8+ T-cell responses occur more rapidly than do changes in aAb titers. These different kinetics may suggest complementary clinical applications for T-cell and aAb measurements.

National Diabetes Programs: Application of capture-recapture to count diabetes?

OBJECTIVE To evaluate the utility of capture-recapture methods using multiple, routinely collected, computerized data sources to estimate the numbers and prevalence of diabetes. Methods employed for regional and national monitoring of diabetes have been too inaccurate or too expensive. RESEARCH DESIGN AND METHODS A survey was undertaken that used four sources of ascertainment to identify prevalent cases of known diabetes in a community of Northern Italy: diabetic clinic and family physicians, hospital discharges, prescriptions, and reagent strips and insulin syringes. Capture-recapture methods were employed to estimate the number of missing cases and to adjust for undercount to accurately estimate the number of people who had diabetes. RESULTS We identified 2,069 unique prevalent cases of known diabetes with the intensive case-finding procedure. The diabetic clinic and family physicians data source identified the largest number of cases. The evaluation of the two sample capture-recapture estimates showed that they were all biased downward because of dependencies between sources. Log-linear modeling was employed to take into account the dependence among all data sources and the heterogeneity of diabetic patients. This method estimated that 2,586 cases existed, resulting in an ascertainment-adjusted prevalence of 2.77% (95% confidence interval, 2.44–3.10). Thus, despite the active case identification, ∼20% could not be identified. However, the number of cases and rates could easily be adjusted using capture-recapture. CONCLUSIONS The study shows that a two-sample capture-recapture estimate could be very biased if the investigator is not assured that the sources are independent. However, if at least three data sources are employed, log-linear models allow estimation of the number and prevalence rate adjusted for the degree of undercount (in spite of both the dependence of data sources and the heterogeneity of the diabetic population). The critical factor, however, is that the application of multiple sources with capture-recapture methods could be applied across broad geographical areas and across time to have cost-effective monitoring of diabetes at local and national level.

Fasting plasma C-peptide and micro- and macrovascular complications in a large clinic-based cohort of type 1 diabetic patients.

OBJECTIVE—A protective effect of residual β-cell function on microvascular complications of type 1 diabetes has been suggested. Our aim was to retrospectively evaluate the association of fasting plasma C-peptide values with micro- and macrovascular complications. RESEARCH DESIGN AND METHODS—We recruited a clinic-based cohort of 471 type 1 diabetic patients born after 1945 and cared for in the period 1994–2004. Centralized measurements and standardized procedures of ascertainment of micro- and macrovascular complications were employed. Individual cumulative averages of A1C up to 2007 were calculated. RESULTS—Residual β-cell secretion was detected even many years after diabetes diagnosis. In multivariate linear regression analysis, fasting plasma C-peptide values were positively associated with age at diagnosis (β = 0.02; P < 0.0001) and triglycerides (β = 0.20; P = 0.05) and inversely associated with diabetes duration (β = −0.03; P < 0.0001) and HDL cholesterol (β = −0.006; P = 0.03). The final model explained 21% of fasting C-peptide variability. With respect to fasting C-peptide values in the lowest tertile (<0.06 nmol/l), higher values were associated with lower prevalence of microvascular complications (odds ratio [OR] 0.59 [95% CI 0.37–0.94]) independently of age, sex, diabetes duration, individual cumulative A1C average during the study period, hypertension, and cardiovascular diseases. No association was evident with macrovascular complications (0.77 [0.38–1.58]). CONCLUSIONS—Our study shows an independent protective effect of residual β-cell function on the development of microvascular complications in type 1 diabetes, suggesting the potential beneficial effect of treatment that allows the preservation of even modest β-cell function over time.

Protective Role of Cannabinoid Receptor Type 2 in a Mouse Model of Diabetic Nephropathy

OBJECTIVE The cannabinoid receptor type 2 (CB2) has protective effects in chronic degenerative diseases. Our aim was to assess the potential relevance of the CB2 receptor in both human and experimental diabetic nephropathy (DN). RESEARCH DESIGN AND METHODS CB2 expression was studied in kidney biopsies from patients with advanced DN, in early experimental diabetes, and in cultured podocytes. Levels of endocannabinoids and related enzymes were measured in the renal cortex from diabetic mice. To assess the functional role of CB2, streptozotocin-induced diabetic mice were treated for 14 weeks with AM1241, a selective CB2 agonist. In these animals, we studied albuminuria, renal function, expression of podocyte proteins (nephrin and zonula occludens-1), and markers of both fibrosis (fibronectin and transforming growth factor-β1) and inflammation (monocyte chemoattractant protein-1 [MCP-1], CC chemokine receptor 2 [CCR2], and monocyte markers). CB2 signaling was assessed in cultured podocytes. RESULTS Podocytes express the CB2 receptor both in vitro and in vivo. CB2 was downregulated in kidney biopsies from patients with advanced DN, and renal levels of the CB2 ligand 2-arachidonoylglycerol were reduced in diabetic mice, suggesting impaired CB2 regulation. In experimental diabetes, AM1241 ameliorated albuminuria, podocyte protein downregulation, and glomerular monocyte infiltration, without affecting early markers of fibrosis. In addition, AM1241 reduced CCR2 expression in both renal cortex and cultured podocytes, suggesting that CB2 activation may interfere with the deleterious effects of MCP-1 signaling. CONCLUSIONS The CB2 receptor is expressed by podocytes, and in experimental diabetes, CB2 activation ameliorates both albuminuria and podocyte protein loss, suggesting a protective effect of signaling through CB2 in DN.