Alterations in pro- and anti-inflammatory mediators are involved in microvascular dysfunction in postmenopausal women with type 2 diabetes mellitus

Evidence has shown that women with type 2 diabetes mellitus (T2DM) have a greater risk of cardiovascular complications compared with men, but this sex difference is not clearly understood. This study assessed the microvascular function and circulatory biomarkers in postmenopausal women (PMW) with T2DM compared with diabetic men and their non-diabetic counterparts. Sixty participants were divided into nondiabetic PMW, PMW with T2DM, non-diabetic men, and diabetic men. Microvascular function was assessed using non-invasive equipment (EndoPAT^®) and reported as reactive hyperemia index (RHI). Anthropometric and cardiovascular parameters were also measured. Two-way ANOVA was performed using sex (women or men) and T2DM (non-diabetic and diabetic) as the two factors. RHI impairment (1.97±0.14) was detected in diabetic PMW compared with women without T2DM (2.5±0.13) accompanied by lower adiponectin levels (T2DM: 9.3±1.2 and CTL: 13.8±1.8 ug/mL, P<0.05). An increase in the Nε-carboxymethyllysine (CML), nitrate/nitrite, and C-reactive protein (CRP) levels were observed in diabetic PMW compared to the other groups. Although a poor glycemia control was seen in diabetic men, neither RHI nor circulatory biomarkers were affected by T2DM. Multiple linear regression stratified by sex and T2DM identified some variables with RHI only in PMW with T2DM: HbA1c (P=0.003), body mass index (P=0.029), CML (P=0.032), and CRP (P=0.006). Diabetic PMW were more susceptible to the deleterious effects of hyperglycemia than men, showing microvascular dysfunction with high levels of pro-inflammatory mediators (CML and CRP) and a lower adiponectin concentration.

Exercise training reduces pulmonary ischaemia-reperfusion-induced inflammatory responses

Physical exercise reduces the deleterious effects of cardiovascular and inflammatory disorders. The purpose of the present study was to evaluate the beneficial effects of physical training on the inflammatory responses following lung ischaemia-reperfusion (IR) in rats. Male Wistar rats were divided into sham-operated animals and sedentary and trained animals submitted to lung IR. The run training programme consisted of 5 sessions.week(-1), each lasting 60 min.day(-1), at 66% of maximal oxygen consumption for 8 weeks. The left pulmonary artery, bronchus and pulmonary vein were occluded for 90 min and reperfused for 2 h. Lung protein extravasation was measured as (125)I-human albumin accumulation, whereas lung neutrophil infiltration was measured as myeloperoxidase activity. Lung IR in sedentary rats resulted in marked increases in protein extravasation and neutrophil influx, and in significant elevations of serum tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels. Physical preconditioning attenuated the increased IR-induced protein leakage without affecting neutrophil influx. It also reduced serum TNF-alpha (and IL-1beta) levels, but had no effect on IL-10 levels. Plasma superoxide dismutase activity was significantly increased in trained IR rats. The present data show that physical preconditioning protects the rat lung from ischaemia-reperfusion injury by attenuating the pulmonary vascular permeability that may be a consequence of reduced levels of tumour necrosis factor-alpha and interleukin-1beta and elevated superoxide dismutase activity.