The relationship of mean platelet volume with the risk and prognosis of cardiovascular diseases

Oxidative stress and autonomic nervous system functions in restless legs syndrome

BACKGROUND

Oxidative stress has been implicated in over 100 disorders in recent years; however, the situation in restless legs syndrome (RLS) has not been studied yet.

METHODS

Fifty patients with RLS not medicated for RLS and 50 sex- and age-matched, healthy controls and controls with no pathology except mild iron deficiency or iron deficiency anaemia were enrolled. Patients with secondary RLS other than iron deficiency were excluded. Total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), arylesterase (ARE), paraoxonase (PON), stimulated paraoxonase (stim-PON), lipid hydroperoxides (LOOHs), acetyl cholinesterase (AChE) and butyryl cholinesterase (BuChE) were measured. Heart rate variability (HRV) analysis was performed.

RESULTS

TOS, ARE and AChE were increased (P = 0·018, P < 0·001 and P < 0·001, respectively), whereas LOOHs were decreased (P < 0·001) in RLS group. TAS, OSI, PON and stim-PON were comparable. Erythrocyte sedimentation rate (ESR) and mean platelet volume (MPV) were increased (P = 0·021 and P = 0·037, respectively) in RLS group. HRV triangular index (HRVi) was lower (P = 0·012) in RLS group. Other HRV parameters were similar.

CONCLUSIONS

Increased AChE and decreased LOOHs, which were influenced by increased PON1, were considered as indicators of efforts towards the protection of dopaminergic activity in central nervous system in RLS group. Increased ESR, MPV and low HRVi indicate elevated sympathetic activity in RLS group. Elevated sympathetic activity might be beneficial in relieving RLS symptoms, also causing increases in TOS. The evidence we found regarding oxidative stress and autonomic nervous system might be seminal in RLS treatment.

The effects of continuous positive airway pressure therapy on mean platelet volume in patients with obstructive sleep apnea

Previous studies have reported increased platelet activation and aggregation in patients with obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) treatment has been shown to decrease platelet activation. We aimed to study the effects of nasal CPAP therapy has on MPV values in patients with severe OSA. Thirty-one patients (21 men; mean age 53.8 ± 9.2 years) with severe OSA (AHI > 30 events/hour) constituted the study group. An age, gender and body mass index (BMI) matched control group was composed 25 subjects (14 men; mean age 49.6 ± 8.5 years) without OSA (AHI < 5 events/hour). We measured MPV values in patients with severe OSA and control subjects and we measured MPV values after 6 months of CPAP therapy in severe OS patients. The median (IQR) MPV values were significantly higher in patients with severe OSA than in control group (8.5 [8.3-9.1] vs. 8.3 [7.5-8.8] fL; p = 0.03). The platelet counts were significantly lower in patients with severe OSA than in control group (217.8 ± 45.9 vs. 265.4 ± 64.0 × 10⁹/L; p = 0.002). The six months of CPAP therapy caused significant reductions in median (IQR) MPV values in patients with severe OSA (8.5 [8.3-9.1] to 7.9 [7.4-8.2] fL; p < 0.001). Six months of CPAP therapy caused significant increase in platelet counts when compared with baseline values (217.8 ± 45.9 to 233.7 ± 60.6 × 10⁹/L; p < 0.001). We have found that the MPV values of patients with severe OSA were significantly higher than those of the control subjects and 6 months CPAP therapy caused significant reductions in the MPV values in patients with severe OSA.

Platelet Indices in Patients With Pulmonary Arterial Hypertension

Background: Pulmonary arterial hypertension (PAH) is a chronic progressive disease characterized by persistent elevation of pulmonary artery pressure. Vasoconstriction, remodeling, and thrombosis cause increased pulmonary vascular resistance and pressure. Previous studies have demonstrated that platelet activation occurs in patients with PAH. Our aim was to assess the mean platelet volume (MPV), an indicator of platelet activation in patients with PAH. Patients and Method: The study group consisted of 22 patients with PAH. An age-, gender-, and body mass index–matched control group was composed of 25 healthy volunteers. All patients underwent physical examination, echocardiography, and diagnostic cardiac catheterization. We measured serum MPV values and platelet counts in patients with PAH and control participant. Results: MPV was significantly higher among the patients with PAH when compared with control group (8.68 ± 0.87 vs 8.02 ± 0.68 fl, respectively; P = .006). Conclusion: We have shown that MPV was elevated in patients with PAH.

Haemostatic system in inflammatory bowel diseases: New players in gut inflammation

Inflammation and coagulation constantly influence each other and are constantly in balance. Emerging evidence supports this statement in acute inflammatory diseases, such as sepsis, but it also seems to be very important in chronic inflammatory settings, such as inflammatory bowel disease (IBD). Patients with Crohn’s disease and ulcerative colitis have an increased risk of thromboembolic events, and several abnormalities concerning coagulation components occur in the endothelial cells of intestinal vessels, where most severe inflammatory abnormalities occur. The aims of this review are to update and classify the type of coagulation system abnormalities in IBD, and analyze the strict and delicate balance between coagulation and inflammation at the mucosal level. Recent studies on possible therapeutic applications arising from investigations on coagulation abnormalities associated with IBD pathogenesis will also be briefly presented and critically reviewed.

Mean platelet volume in patients with subclinical hypothyroidism

Subclinical hypothyroidism (SCH) is frequently encountered in the general population. Since it is generally asymptomatic, these patients are mostly identified through routine screening or evaluation of non-specific symptoms. It has been suggested as a risk factor for cardiovascular disease. On the other hand, mean platelet volume (MPV), which is a determinant of platelet function, is an independent risk factor for cardiovascular disease. The aim of this study was to evaluate MPV values in subclinical hypothyroidic patients when they were subclinical hypothyroidic and became euthyroidic after 12 weeks of levothyroxine replacement therapy. Sixty patients with subclinical hypothyroidism and 78 euthyroid healthy subjects matched for age, gender and body mass index were enrolled in the study. None of the study subject had diabetes, hypertension or dyslipidemia. All the study subjects were evaluated by biochemical and platelet parameters. Subclinical hypothyroidic patients were then reevaluated with the same parameters when they became euthyroid after 12 weeks of levothyroxine treatment. Platelet counts and metabolic parameters, except serum triglyceride and high density lipoprotein cholesterol (HDLC) levels, were similar between the two groups. Serum triglyceride and MPV values were significantly higher (pTG=0.007 and pMPV<0.001) while HDLC levels were lower (pHDLC=0.008) in the subclinical hypothyroidic group. MPV was found to be correlated with only antithyroid peroxidase (anti-TPO) antibody levels (P<0.001). MPV values were decreased after subclinical hypothyroidic patients became eythyroid. However, post-treatment MPV values were still higher (p=0.035) in the patient group than in control group. These results suggest that subjects with SCH are susceptible to increased platelet activation and increased MPV values which contribute to increased risk of cardiovascular complications.

Platelet indices in patients with acute pulmonary embolism

Previous studies have demonstrated that platelet activation occurs in patients with acute pulmonary embolism (PE). The aim of this study was to assess the mean platelet volume (MPV), an indicator of platelet activation in patients with acute PE. The study group consisted of 107 patients with acute PE. Seventy subjects matched for age, gender, body mass index (BMI) and frequency of concomitant diseases served as control group. All patients and control subjects underwent physical examination and echocardiography. We measured MPV values and platelet counts on admission. MPV was significantly higher among patients with acute PE when compared with control group (9.6 ± 1.0 vs. 8.1 ± 0.8 fL respectively; < 0.001). Platelet count was significantly lower among acute PE patients when compared with control group (227.1 ± 77.0 vs. 268.7 ± 58.4 × 10(9)/L, respectively; < 0.001). MPV was correlated with right ventricular (RV) diameter (p < 0.001, r = 0.33) in correlation analysis. In linear regression analysis, MPV was independently correlated with RV dimension (β = 0.29, p = 0.001). We have shown that MPV, an indicator of platelet activation, was increased in patients with acute PE and it was correlated with RV diameter. Platelet count was decreased in patients with acute PE.

Platelet abnormalities in diabetes mellitus

Patients with diabetes mellitus (DM) have accelerated atherosclerosis, which is the main underlying factor contributing to the high risk of atherothrombotic events in these patients. Atherothrombotic complications are the leading cause of morbidity and mortality in patients with DM. Among factors contributing to the prothrombotic condition which characterise patients with DM, platelet hyperreactivity plays a pivotal role. Platelets of DM patients are characterised by dysregulation of several signalling pathways leading to intensified adhesion, activation and aggregation. Multiple mechanisms are involved in platelet dysfunction of patients with DM, which can be categorised as follows: a) hyperglycaemia, b) insulin deficiency and resistance, c) associated metabolic conditions, and d) other cellular abnormalities.The present manuscript aims to provide an overview on the current status of knowledge on platelet abnormalities that characterise patients with DM.

Mean platelet volume is increased in patients with severe obstructive sleep apnea

Increased platelet activation and aggregation which are closely related to cardiovascular complications have been reported in patients with obstructive sleep apnea (OSA). The aim of this study was to assess the mean platelet volume (MPV), an indicator of platelet activation in patients with OSA. The 95 subjects referred for evaluation of OSA underwent overnight polysomnography. Blood samples were taken for MPV determination. According to the apnea-hypopnea index (AHI), subjects were divided into three groups; group 1: control subjects without OSA (AHI < 5, n = 24), group 2: patients with mild to moderate OSA (AHI: 5-30, n = 42), and group 3: severe OSA (AHI > 30, n = 29). Body mass index (BMI) of patients with severe OSA was significantly higher than control subjects (31.5 ± 4.0 vs. 28.2 ± 5.0; p = 0.02). The MPV was significantly higher in patients with severe OSA than in the control group (8.9 ± 1.0 vs. 8.2 ± 0.7 fl; p = 0.01). Correlation analysis within 71 patients with OSA indicated that MPV was correlated with AHI (p < 0.001, r = 0.44) and DI (p = 0.001, r = 0.37). In multivariate regression analysis, when MPV was taken as independent with other study variables which are potential confounders such as age, gender and BMI, MPV was independently correlated with both AHI (β = 0.44, p < 0.001) and DI (β = 0.38, p < 0.001). We have shown that MPV was significantly higher in patients with severe OSA when compared with control subjects and MPV was correlated with AHI and DI.

Adipocytokines in atherothrombosis: focus on platelets and vascular smooth muscle cells

Visceral obesity is a relevant pathological condition closely associated with high risk of atherosclerotic vascular disease including myocardial infarction and stroke. The increased vascular risk is related also to peculiar dysfunction in the endocrine activity of adipose tissue responsible of vascular impairment (including endothelial dysfunction), prothrombotic tendency, and low-grade chronic inflammation. In particular, increased synthesis and release of different cytokines, including interleukins and tumor necrosis factor-α (TNF-α), and adipokines—such as leptin—have been reported as associated with future cardiovascular events. Since vascular cell dysfunction plays a major role in the atherothrombotic complications in central obesity, this paper aims at focusing, in particular, on the relationship between platelets and vascular smooth muscle cells, and the impaired secretory pattern of adipose tissue.

Mean platelet volume is associated with insulin resistance in non-obese, non-diabetic patients with coronary artery disease

BACKGROUND AND PURPOSE

Mean platelet volume (MPV), an indicator of platelet activation, has been shown to be elevated in patients with coronary artery disease (CAD) in some studies. Insulin resistance contributes to increased platelet activation and it is one of the risk factors for CAD. The aim of this study was to assess the relationship between insulin resistance and MPV in non-obese, non-diabetic patients with CAD.

METHODS AND SUBJECTS

Seventy-seven non-obese, non-diabetic CAD patients were divided into two groups, insulin resistant and insulin sensitive according to the homeostasis model assessment insulin resistance index (HOMA-IR). The insulin-resistant group was composed of 45 patients (30 males/15 females; mean age 59.8±11.1 years). The insulin-sensitive group was composed of 32 patients (17 males/15 females; mean age 58.9±12.2 years).

RESULTS

Insulin and HOMA-IR values were significantly higher in insulin-resistant CAD patients than in insulin-sensitive CAD patients. The MPV values were significantly higher in insulin-resistant CAD patients than in insulin-sensitive CAD patients (8.6±1.0 fl vs. 8.0±0.7 fl; respectively, p=0.01). The MPV was poorly correlated with HOMA-IR (r=0.30, p=0.054) and insulin (r=0.22, p=0.053).

CONCLUSIONS

We have shown that MPV was significantly elevated in insulin-resistant non-obese, non-diabetic CAD patients when compared to insulin-sensitive non-obese, non-diabetic CAD patients.