An Observational Study Suggests That Natural HAdV-36 Infection Decreases Blood Glucose Levels without Affecting Insulin Levels in Obese Young Subjects.

Human adenovirus-36 (HAdV-36) infection has been linked to obesity, low lipid levels, and improvements in blood glucose levels and insulin sensitivity in animal models and humans, although epidemiological studies remain controversial. Therefore, this study investigated the relationship between HAdV-36 seropositivity and glycemic control in youths. This observational study examined 460 youths (246 with normal weight and 214 obese subjects). All participants underwent assessments for anthropometry, blood pressure, circulating fasting levels of glucose, lipids, insulin, and anti-HAdV-36 antibodies; additionally, the homeostatic model assessment of insulin resistance (HOMA-IR) was calculated. In all, 57.17% of the subjects were HAdV-36 seropositive. Moreover, HAdV-36 seroprevalence was higher in obese subjects compared to their normal weight counterparts (59% vs. 55%). BMI (33.1 vs. 32.3 kg/m2, p = 0.03), and waist circumference (107 vs. 104 cm, p = 0.02), insulin levels (21 vs. 16.3 µU/mL, p = 0.003), and HOMA-IR (4.6 vs. 3.9, p = 0.02) were higher in HAdV-36-positive subjects with obesity compared to seronegative subjects. In the obese group, HAdV-36 seropositivity was associated with a reducing effect in blood glucose levels in a model adjusted for total cholesterol, triglyceride levels, age and sex (ß = -10.44, p = 0.014). Furthermore, a statistically significant positive relationship was observed between HAdV-36 seropositivity and insulin levels in the obesity group. These findings suggest that natural HAdV-36 infection improves glycemic control but does not ameliorate hyperinsulinemia in obese subjects.

Presence of Adenovirus-36 DNA in Adipose Tissue of Women: Relationship with Adipocyte Morphology and the Expression of C/EBPß and HIF-1α.

BACKGROUND: Human adenovirus 36 (HAd36) infection has been associated with obesity. Experiments using 3T3-L1 adipocyte cultured cells and human adipose stem cells (hASCc) have shown that HAd36 stimulates the expression of genes implicated in cell differentiation and increased lipid accumulation. The presence of HAd36 in adipose tissue of overweight and obese women has also been confirmed. This study aims to analyze the presence of HAd36 DNA in the adipose tissue of women undergoing surgery for weight reduction and its relationship with obesity through changes in adipocyte morphology as well as the expression of C/EBPß and HIF-1α. METHODS: Fifty-two subcutaneous adipose tissue biopsies were collected. The anthropometric parameters measured were weight, height, skin folds, body circumferences, and body fat percentage. Biochemical measures were performed for glucose, cholesterol, triglycerides, cholesterol HDL-c, and LDL-c. The presence of HAd36 DNA was performed by conventional PCR. Adipocyte morphology was analyzed in H&E-stained sections using ImageJ/Fiji software. The expression of genes C/EBPß, HIF-1α and ß-actin was determined using TaqMan probes. RESULTS: HAd36 DNA was detected in 31% of adipose tissue samples. The presence of viral DNA was not significantly associated with anthropometric, clinical, or metabolic measurements, or with changes in adipose tissue morphology. The levels of mRNA expression for C/EBPß and HIF-1α did not show significant differences between positive and negative samples for HAd36 (p>0.05). CONCLUSION: The presence of HAd36 DNA in adipose tissue was identified, but it was not related to morphological changes of adipocytes, or the expression of C/EBPß and HIF-1α. Further studies are needed to confirm these findings.

A possible association between the -2518 A>G MCP-1 polymorphism and insulin resistance in school children

ABSTRACT Objective Monocyte chemoattractant protein 1 (MCP-1) has been suggested to be involved in the pathophysiology of insulin resistance (IR); therefore, variants in the MCP-1 gene may contribute to the development of this disease. The aim of this study was to analyze the relationship of the -2518 A>G MCP-1 (rs1024611) gene polymorphism with insulin resistance in Mexican children. Subjects and methods A cross-sectional study was performed in 174 children, including 117 children without insulin resistance and 57 children with IR, with an age range of 6-11 years. Levels for serum insulin and high-sensitivity C-reactive protein were determined. The -2518 A>G MCP-1 polymorphism was identified by the polymerase chain reaction-restriction fragment length polymorphism method. Insulin resistance was defined as a HOMA-IR in the upper 75th percentile, which was ≥ 2.4 for all children. Results Genotype frequencies of the rs1024611 polymorphism for the insulin-sensitive group were 17% AA, 48% AG and 35% GG, and the frequency of G allele was 59%, whereas frequencies for the insulin-resistant group were 12% AA, 37% AG and 51% GG, and the frequency of G allele was 69%. The genotype and allele frequencies between groups did not show significant differences. However, the GG genotype was the most frequent in children with IR. The GG genotype was associated with insulin resistance (OR = 2.2, P = 0.03) in a genetic model. Conclusion The -2518 A>G MCP-1 gene polymorphism may be related to the development of insulin resistance in Mexican children.

El factor inhibidor de la migración de macrófagos y su relación con la obesidad y la diabetes / Macrophage migration inhibitory factor and its relationship with obesity and diabetes

En diversos estudios se ha identificado que la obesidad y principalmente el aumento de adiposidad en la región abdominal, se asocia con inflamación de grado bajo, resistencia a la insulina (RI), homeostasis alterada de la glucosa y con sus comorbilidades tales como la diabetes mellitus tipo 2 (DMT2), la hipertensión, las dislipidemias y las enfermedades cardiovasculares. El factor inhibidor de la migración de macrófagos (MIF) es una citocina proinflamatoria involucrada en enfermedades autoinmunes e inflamatorias. Sin embargo, actualmente, se sugiere que el MIF está involucrado en el proceso inflamatorio que acompaña a la obesidad, así como en el control metabólico de las complicaciones asociadas a la obesidad. Los diferentes estudios muestran de manera consistente, el aumento en los niveles séricos del MIF en personas con obesidad, diabetes tipo 2 y en los diabéticos que presentan complicaciones microvasculares (la nefropatía, la retinopatía y el síndrome de pie diabético). La relación del MIF con la regulación del metabolismo de la glucosa y la apoptosis de las células β pancreáticas, así como la asociación de algunos polimorfismos funcionales en el promotor del gen del MIF con la obesidad y la diabetes. Esta revisión resume conocimientos basados en estudios clínicos y epidemiológicos sobre el papel del MIF en la obesidad y la diabetes tipo 2.

Several studies have found that obesity and increased adiposity mainly in the abdominal region, are associated with low-grade inflammation, insulin resistance (IR), impaired glucose homeostasis and comorbidities such as type 2 diabetes mellitus (T2D) and cardiovascular disease. The macrophage migration inhibitory factor (MIF), is a proinflammatory cytokine involved in autoimmune and inflammatory diseases. However, currently it is suggested that MIF is involved in the inflammatory process associated with obesity and the metabolic control of the complications associated with obesity. Different studies show consistently, increased serum levels of MIF in subjects with obesity, type 2 diabetes and diabetics with microvascular complications (nephropathy, retinopathy and diabetic foot syndrome). The relationship of the MIF to the regulation of glucose metabolism and apoptosis of pancreatic β cells, and the association of some functional polymorphisms in the promoter of the MIF gene with obesity and diabetes.This review summarizes, the knowledge based on clinical and epidemiological studies on the role of MIF in obesity and type 2 diabetes.