Arsenic exposure during pregnancy and postpartum maternal glucose tolerance: evidence from Bangladesh

Background Arsenic exposure has been associated with gestational diabetes mellitus. However, the extent to which arsenic exposure during pregnancy is associated with postpartum glucose intolerance is unknown. Methods We studied 323 women in Bangladesh. We assessed arsenic exposure in early pregnancy via toenail and water samples. We measured fasting glucose and insulin in serum at a mean (SD) of 4.0 (3.5) weeks post-delivery. We ran covariate-adjusted, linear regression models to examine associations of arsenic concentrations with HOMA-IR, a marker of insulin resistance, and HOMA-β, a marker of beta cell function. Results Median (IQR) arsenic concentration was 0.45 (0.67) μg/g in toenails and 2.0 (6.5) μg/L in drinking water. Arsenic concentrations during pregnancy were not associated with insulin resistance or beta cell function postpartum. HOMA-IR was 0.07% (− 3.13, 3.37) higher and HOMA-β was 0.96% (− 3.83, 1.99) lower per IQR increment in toenail arsenic, but effect estimates were small and confidence intervals crossed the null. Conclusions Although arsenic exposure during pregnancy has been consistently associated with gestational diabetes mellitus, we found no clear evidence for an adverse effect on postpartum insulin resistance or beta cell function.

Association of Serum Ferritin with Risk of Anemia in Non-Diabetic Adolescents with Family History of Type 2 Diabetes Mellitus

Background: Controversy occurs in the relationship between serum ferritin levels, insulin resistance and risk of developing anemia in adolescents with family history of diabetes. Aims & Objectives: This study was designed to find out the association between serum ferritin levels with risk of developing anemia in non-diabetic adolescents with family history of type 2 diabetes mellitus (T2DM). Materials & Methods: A descriptive cross-sectional was conducted in a local medical institute of Lahore. Study included 50 non-diabetic, non-obese male / female adolescent with family history of type 2 diabetes mellitus and 50 healthy male/female non-obese adolescents without family history of T2DM considered as controls. Level of serum ferritin and serum insulin was estimated by Enzyme Linked Immunosorbent Assay. Blood glucose was estimated by auto-analyzer. Insulin resistance was calculated by HOMA-IR index and beta cell function was assessed by HOMA- beta index. Results: Levels of fasting blood sugar, insulin resistance were found to be increased with decreased level of serum ferritin and decrease beta cell function in both male as well as female cases as compared to controls. Negative correlation was found between serum ferritin and insulin resistance while a positive correlation was found between serum ferritin and beta cell function. Conclusions: Low level of serum ferritin is associated with reduced beta cell function and increased insulin resistance. This may increase the risk of developing iron deficiency anemia that can affect both immune system as well as increase susceptibility to infections.

The Current State of Beta-Cell-Mass PET Imaging for Diabetes Research and Therapies

Diabetes is a chronic metabolic disease affecting over 400 million people worldwide and one of the leading causes of death, especially in developing nations. The disease is characterized by chronic hyperglycemia, caused by defects in the insulin secretion or action pathway. Current diagnostic methods measure metabolic byproducts of the disease such as glucose level, glycated hemoglobin (HbA1c), insulin or C-peptide levels, which are indicators of the beta-cell function. However, they inaccurately reflect the disease progression and provide poor longitudinal information. Beta-cell mass has been suggested as an alternative approach to study disease progression in correlation to beta-cell function, as it behaves differently in the diabetes physiopathology. Study of the beta-cell mass, however, requires highly invasive and potentially harmful procedures such as pancreatic biopsies, making diagnosis and monitoring of the disease tedious. Nuclear medical imaging techniques using radiation emitting tracers have been suggested as strong non-invasive tools for beta-cell mass. A highly sensitive and high-resolution technique, such as positron emission tomography, provides an ideal solution for the visualization of beta-cell mass, which is particularly essential for better characterization of a disease such as diabetes, and for estimating treatment effects towards regeneration of the beta-cell mass. Development of novel, validated biomarkers that are aimed at beta-cell mass imaging are thus highly necessary and would contribute to invaluable breakthroughs in the field of diabetes research and therapies. This review aims to describe the various biomarkers and radioactive probes currently available for positron emission tomography imaging of beta-cell mass, as well as highlight the need for precise quantification and visualization of the beta-cell mass for designing new therapy strategies and monitoring changes in the beta-cell mass during the progression of diabetes.

Heterogeneity of beta-cell function in subjects with multiple islet autoantibodies in the TEDDY family prevention study - TEFA

Background Individuals with multiple islet autoantibodies are at increased risk for clinical type 1 diabetes and may proceed gradually from stage to stage complicating the recruitment to secondary prevention studies. We evaluated multiple islet autoantibody positive subjects before randomisation for a clinical trial 1 month apart for beta-cell function, glucose metabolism and continuous glucose monitoring (CGM). We hypothesized that the number and type of islet autoantibodies in combination with different measures of glucose metabolism including fasting glucose, HbA1c, oral glucose tolerance test (OGTT), intra venous glucose tolerance test (IvGTT) and CGM allows for more precise staging of autoimmune type 1 diabetes than the number of islet autoantibodies alone. Methods Subjects (n = 57) at 2–50 years of age, positive for two or more islet autoantibodies were assessed by fasting plasma insulin, glucose, HbA1c as well as First Phase Insulin Response (FPIR) in IvGTT, followed 1 month later by OGTT, and 1 week of CGM (n = 24). Results Autoantibodies against GAD65 (GADA; n = 52), ZnT8 (ZnT8A; n = 40), IA-2 (IA-2A; n = 38) and insulin (IAA; n = 28) were present in 9 different combinations of 2–4 autoantibodies. Fasting glucose and HbA1c did not differ between the two visits. The estimate of the linear relationship between log2-transformed FPIR as the outcome and log2-transformed area under the OGTT glucose curve (AUC) as the predictor, adjusting for age and sex was − 1.88 (− 2.71, − 1.05) p = 3.49 × 10–5. The direction of the estimates for all glucose metabolism measures was positive except for FPIR, which was negative. FPIR was associated with higher blood glucose. Both the median and the spread of the CGM glucose data were significantly associated with higher glucose values based on OGTT, higher HbA1c, and lower FPIR. There was no association between glucose metabolism, autoantibody number and type except that there was an indication that the presence of at least one of ZnT8(Q/R/W) A was associated with a lower log2-transformed FPIR (− 0.80 (− 1.58, − 0.02), p = 0.046). Conclusions The sole use of two or more islet autoantibodies as inclusion criterion for Stage 1 diabetes in prevention trials is unsatisfactory. Staging type 1 diabetes needs to take the heterogeneity in beta-cell function and glucose metabolism into account. Trial registration ClinicalTrials.gov identifier: NCT02605148, November 16, 2015