Envolvimento da inflamação subclínica e do estresse oxidativo na resistência à insulina associada a obesidade / Involvement of the subclinical inflammation and oxidative stress in the obesity-associated insulin resistance

A epidemia global da obesidade é um dos mais importantes problemas de saúde pública. Excessiva adiposidade é um crucial fator de risco no surgimento de várias doenças metabólicas, incluindo hipertensão, diabetes mellitus do tipo 2 e doença do fígado gorduroso não alcoólico. Essas condições patológicas estão estritamente associadas com a resistência à insulina. Baseado nos esforços das últimas décadas, ocorreu marcante desenvolvimento na investigação sobre resistência à insulina induzida pela obesidade, especialmente em termos do mecanismo envolvido neste processo. Dentre esses, a inflamação subclínica ou crônica de baixo grau é o mais aceito atualmente. Este estado inflamatório é caracterizado por altos níveis circulantes de citocinas inflamatórias, incluindo TNFα e ILß, e aumentado infiltração de macrófagos em tecidos periféricos. No entanto, tem ocorrido grande interesse no papel que o estresse oxidativo desempenha na indução da resistência à insulina. Sob ativação, muitas células imunes geram radicais livres e, da mesma maneira, a síntese de espécies reativas de oxigênio promovem um status inflamatório. Estudos têm mostrado níveis elevados de espécies reativas e estresse oxidativo em indivíduos e animais obesos e/ou resistentes a insulina; isso parece estar associado a redução da função e da atividade e biogênese mitocondrial causada pelo aumento de lipídeos circulantes e maior deposição de gordura ectópica. Essa revisão discorre sobre o mecanismo fisiopatológico de como a inflamação subclínica induz resistência à insulina na obesidade. Ainda, descreve o papel que o estresse oxidativo desempenha neste processo, bem como a produção de radicais livres na obesidade

The global epidemic of obesity is a major public health problem. Excess adiposity is a major risk factor in the progress of various metabolic disorders including dyslipedima, hypertension, type 2 diabetes, and nonalcoholic fatty liver disease. These pathological states are strongly associated with insulin resistance. On the basis of efforts over the last decades, there have been remarkable developments in the investigation of obesity-induced insulin resistance, especially in terms of the mechanisms involved in this process. Among these, low-grade chronic inflammation is the most accepted actually. This inflammation state is characterized by high circulating levels of inflammatory cytokines, including TNFα and ILß, and increased macrophage infiltration in peripheral tissues. However, there has been a profound interest in the role that oxidative stress plays to induce insulin resistance. Upon activation, many immune cells generate free radicals, and in the same way, the synthesis of reactive oxygen species promotes an inflammatory status. Studies have shown high levels of reactive species and oxidative stress in obese and / or insulin resistant people and animals; it appears to be associated with reduced function and mitochondrial activity and biogenesis caused by increased circulating lipids and increased deposition of ectopic fat. This review discourse on the pathophysiological mechanism of how the subclinical inflammation induce obesity-associated insulin resistance. Also discuss the role that oxidative stress plays to induce insulin resistance, as well as the relation of the free radicals and cytokines in the obesity.

Acquired Bilateral Dyspigmentation on Face and Neck: Clinically Appropriate Approaches

Facial dyspigmentation in Asian women often poses diagnostic and therapeutic challenges. Recently, a distinctive bilateral hyperpigmentation of face and neck has occasionally been observed. This study was performed to investigate the clinico-pathological features of this dyspigmentation as well as proper treatment approaches. We retrospectively investigated the medical records including photographs, routine laboratory tests, histopathologic studies of both lesional and peri-lesional normal skin and patch test of thirty-one patients presented acquired bizarre hyperpigmentation on face and neck. The mean age of patients was 52.3 years and the mean duration of dyspigmentation was 24.2 months. In histologic evaluations of lesional skin, a significantly increased liquefactive degeneration of basal layer, pigmentary incontinence and lymphocytic infiltration were noted, whereas epidermal melanin or solar elastosis showed no statistical differences. Among 19 patients managed with a step-by-step approach, seven improved with using only topical anti-inflammatory agents and moisturizer, and 12 patients gained clinical benefit after laser therapy without clinical aggravation. Both clinical and histopathologic findings of the cases suggest a distinctive acquired hyperpigmentary disorder related with subclinical inflammation. Proper step-by-step evaluation and management of underlying subclinical inflammation would provide clinical benefit.

Inflamacion subclinica en diabetes tipo 1 infanto-juvenil / Subclinical inflammation in children and adolescents with type 1 diabetes / Inflamação subclínica em crianças e adolescentes com diabetes tipo 1

En ninos y adolescentes con diabetes tipo 1 (DT1) puede aparecer precozmente un estado de inflamacion subclinica. El objetivo del trabajo fue determinar los niveles plasmaticos de moleculas proinflamatorias en una poblacion infanto-juvenil con DT1, sin evidencias clinicas de complicaciones vasculares y correlacionar estos parametros entre si y con el grado de control glucemico y tiempo de evolucion de la enfermedad. Se estudiaron 42 pacientes con DT1 (21M/21F), de 10 a 13 anos, que se compararon con un grupo control. Se evaluaron: recuento de leucocitos, formas solubles de E-selectina (sE-S) y molecula de adhesion celular vascular 1 (VCAM-1), mieloperoxidasa (MPO), TNF-á, Fibrinogeno (Fg) y uPCR. Los datos se expresaron como mediana y rango intercuartil. Los diabeticos presentaron niveles aumentados de: sE-S [108 (69-150) vs. 68 (52-86) ng/mL, p=0,003], VCAM-1 [785 (732-835) vs 712 (658-758) ng/mL, p=0,04], uPCR [1,00 (0,67-1,70) vs. 0,20 (0,18-0,87) mg/L, p=0,01]. No se observaron diferencias en las moleculas estudiadas segun el grado de control glucemico y tiempo de evolucion de la enfermedad. La uPCR se correlaciono con glucemia en ayunas, HbA1c, sE-S y VCAM1. Los niveles elevados de uPCR, sE-S y VCAM-1 sugieren un estado proinflamatorio asociado a activacion endotelial en ninos con DT1, potenciando el riesgo de enfermedad vascular.

In children and adolescents with type 1 diabetes (T1D), clinical manifestations of vascular complications are uncommon; however, endothelial disturbance and a pro-inflammatory state can emerge early. The objectives of this work were: I) to determine plasma levels of proinflammatory molecules in a T1D pediatric population with no clinical evidence of vascular complications; II) to correlate these parameters with each other, and with glycemic control degree and disease duration. Forty-two patients with T1D (21 M/21W), aged 10 and 13 years and an evolution time not more than 6 years were compared with a control group. The biochemical parameters evaluated were: WBC, sE-S and VCAM-1, MPO, TNF-á, hsCRP and plasma Fg. Glycemic control was performed by determining fasting glucose and HbA1c. Data were expressed as the median and interquartile range. Increased levels of sE-S [108 (69-150) vs. 68 (52-86) ng/mL, p=0.003], VCAM-1 [785 (732-835) vs. 712 (658-758) ng/mL, p=0.04], hsCRP [1.00 (0.67-1.70) vs. 0.20 (0.18- 0.87) mg/L, p=0.01] were found in diabetic patients compared with the control group. No differences in the studied molecules were observed when diabetic patients were grouped according to glycemic control degree and evolution of the disease. hsCRP correlated with fasting glucose, HbA1c, sE-S and VCAM-1. High hsCRP, sE-S and VCAM-1 levels suggest a proinflammatory state associated with endothelial activation in children and adolescents with T1D, potentiating the risk of vascular disease.

Em crianças e adolescentes com diabetes tipo 1 (DT1), um estado de inflamação subclínica pode aparecer de forma precoce. O objetivo do trabalho foi determinar os níveis plasmáticos de moléculas pró-inflamatórias em uma população infanto-juvenil com DM1 sem evidências clínicas de complicações vasculares e correlacionar estes parâmetros, entre si com o grau de controle glicêmico e tempo de evolução da doença. Foram estudados 42 pacientes com DM1 (21M/21F), de 10 a 13 anos, que foram comparados com um grupo controle. Foram avaliadas a contagem de leucócitos, formas solúveis de E-selectina (sE-S) e molécula de adesão celular vascular 1 (VCAM-1), mieloperoxidase (MPO), TNF-á, fibrinogênio (Fg) e PCRus. Os dados foram expressos como mediana e intervalo interquartil. Os pacientes diabéticos apresentaram níveis aumentados de SE-S [108 (69-150) vs. 68 (52-86) ng/mL, p=0,003], VCAM-1 [785 (732-835) vs. 712 (658-758) ng/mL, p=0,04], PCRus [1,00 (0,67-1,70) vs. 0,20 (0,18-0,87) mg/L, p=0,01]. Não foram observadas diferenças nas moléculas estudadas segundo o grau de controle glicêmico e tempo de evolução da doença. O PCRus foi correlacionado com glicemia em jejum, HbA1c, sES e VCAM1. Os níveis elevados de PCRus, sE-S e VCAM-1 sugerem um estado pró-inflamatório associado com a ativação do endotélio em crianças com DM1, aumentando o risco de doença vascular.

Lipid Accumulation Product Is Associated with Insulin Resistance, Lipid Peroxidation, and Systemic Inflammation in Type 2 Diabetic Patients

BACKGROUND: Lipid accumulation product (LAP) is a novel biomarker of central lipid accumulation related to risk of diabetes and cardiovascular disease. In this study, we assessed the association of LAP with glucose homeostasis, lipid and lipid peroxidation, and subclinical systemic inflammation in diabetic patients. METHODS: Thirty-nine male and 47 female type 2 diabetic patients were assessed for anthropometrics and biochemical measurements. LAP was calculated as [waist circumference (cm)-65]x[triglycerides (mmol/L)] in men, and [waist circumference (cm)-58]x[triglycerides (mmol/L)] in women. Associations of LAP with fasting glucose, insulin, insulin resistance index, lipid and lipoprotein levels, malondialdehyde, and high-sensitive C-reactive protein (hs-CRP) were assessed. RESULTS: Mean age and LAP index were 53.6+/-9.6 and 51.9+/-31.2 years, respectively. After adjustments for age, sex and body mass index status, a significant positive correlation was observed between LAP index and fasting glucose (r=0.39, P<0.001), and homeostasis model assessment of insulin resistance (r=0.31, P<0.05). After additional adjustment for fasting glucose levels, antidiabetic and antilipidemic drugs, the LAP index was also correlated to total cholesterol (r=0.45, P<0.001), high density lipoprotein cholesterol (HDL-C) levels (r=-0.29, P<0.05), triglycerides to HDL-C ratio (r=0.89, P<0.001), malondialdehyde (r=0.65, P<0.001), and hs-CRP levels (r=0.27, P<0.05). CONCLUSION: Higher central lipid accumulation in diabetic patients was related to higher insulin resistance, oxidative stress and systemic inflammation.