Mean platelet volume: a predictor of mortality in diabetic and non-diabetic patients with STEMI?

Specificities of primary and secondary prevention of lower extremity artery disease in patients with diabetes mellitus

Diabetes mellitus (DM) is a major risk factor for lower extremity arterial disease (LEAD) and about 20% of symptomatic patients with LEAD have DM. In subjects with DM, LEAD is a cause of morbidity and mortality. DM typically causes complications in the form of macro- and microangiopathy. In these patients, macroangiopathy manifests as atherosclerosis like in non-diabetic patients. However, its course is accelerated due to accompanying risk factors like hyperlipidemia and hypertension, with cumulative effects. Other factors are also relevant such as inflammation, endothelial dysfunction, platelet activation, blood rheological properties, hypercoagulability, and factors stimulating vascular smooth muscle cell proliferation. Additionally, DM is a risk factor for restenosis and amputation. DM is strongly associated with femoral-popliteal and tibial LEAD, which manifests earlier in patients with DM and may progress more rapidly to critical limb ischemia. Diabetic microangiopathy is characterized by arteriolosclerosis and interstitial fibrosis which additionally affects progression and outcomes of angiopathy of lower limbs. Glycemic control particularly decreases microangiopathic complications, while prevention of macrovascular complications requires treatment of accompanying risk factors like hypertension and dyslipidemia.

Effect of metformin on reducing platelet dysfunction in gestational diabetes mellitus: a randomized controlled trial

OBJECTIVES

To evaluate the effect of metformin in improving platelet dysfunction in women with gestational diabetes mellitus (GDM).

PATIENTS AND METHODS

A randomized controlled trial was conducted on pregnant women diagnosed with GDM. Singleton low-risk pregnancies meeting the inclusion criteria were randomly allocated at 27-31 weeks to receive metformin and placebo through the rest of pregnancy. Thirty-seven and 39 cases were recruited into the metformin group and the placebo group, respectively. MPVs, P-selectin, and 8-isoprostane levels were determined at the time of allocation and 6 weeks after treatment. Obstetric and neonatal outcomes were also assessed.

RESULTS

Most baseline characteristics of the two groups were comparable. The levels of P-selectin after 6 weeks of treatment were significantly higher in the metformin group (68.9 ± 14.4 vs 60.6 ± 11.3; P-value = 0.006), indicating more platelet activation. All of the obstetric and neonatal outcomes were comparable except that birth weight was significantly lower in the metformin group (3018 ± 364 g vs 3204 ± 393 g; P-value = 0.037).

CONCLUSION

Metformin, in addition to diet and lifestyle modifications, does not improve or worsen oxidative stress and platelet dysfunction in women with GDM. Nevertheless, metformin significantly reduces fetal weight in women with GDM, theoretically preventing macrosomia.

The relationship between mean platelet volume and resistant hypertension

OBJECTIVE

Resistant hypertension (RH) is associated with an increased risk of cardiovascular events.Mean platelet volume (MPV) has been shown to indicate platelet activation and is associated with increased cardiovascular disease risk. In our study, we aimed to evaluate the relationship between mean platelet volume and resistant hypertension.

METHOD

A total of 279 patientswere included in our study and divided into three groups (GroupI: seventy-eight patients with resistant hypertension, group II: seventy-nine patients with controlled hypertension and group III: one-hundred-five patients without hypertension). Routine laboratory tests and ambulatory blood pressure measurement (ABPM) were followed up in all patients.

RESULTS

Of the patients in the study, 25% were female while 75% were male, and the mean age was 56.5 ± 11.8 years. The mean MPV values were found to be 9.34 ± 1.49 fL in the RHT group, 8.82 ± 0.83 fLin the controlled HT group, and 8.5 ± 0.85 fL in the normotensive individuals, and there was a significant correlation between the RHT group and the other groups (RHT versus controlled HT p1 = 0.008, RHT versus normotensive individuals p2 < 0,001). When we compared controlled HT and normotensive individuals, no significant relationship was found between MPV values (p3 = 0,157).

CONCLUSION

The MPV value was found to be higher in resistant hypertensive patients compared to controlled hypertensive and normotensive patients. MPV values can be used to predict adverse cardiovascular events in RHT patients.

Platelet Distribution Width and Mortality in Hemodialysis Patients

Objectives

The association between platelet distribution width (PDW) and mortality in hemodialysis (HD) patients has received little attention.

Methods

We retrospectively enrolled HD patients in a single center from January 1, 2008, to December 30, 2011. The primary and secondary endpoints were all-cause and cardiovascular mortality, respectively. The association between PDW and mortality was estimated by Cox regression model.

Results

Of 496 patients, the mean age was 52.5 ± 16.6 years, and the Charlson comorbidity index was 4.39 ± 1.71. During the follow-up period of 48.8 ± 6.7 months, 145 patients (29.2%) died, including 74 (14.9%) cardiovascular deaths. 258 (52.0%) with PDW < 16.31% were in the low group and 238 (48.0%) in those with PDW ≥ 16.31% according to cut-off for all-cause mortality by receiving-operator characteristics. After adjusting for confounding factors, high PDW values were independently associated with higher risk of all-cause (hazards ratio (HR) = 1.49, 95% confidence interval (CI) 1.15-6.82) and cardiovascular deaths (HR = 2.26, 95% CI 1.44-3.63) in HD patients. When comparing with quartile 1 of PDW, quartile 4 of PDW was independently associated with a higher risk of all-cause (HR = 1.59, 95% CI 1.18-5.30) and cardiovascular deaths (HR = 2.71, 95% CI 1.49-3.76) in HD patients.

Conclusions

Baseline PDW was independently associated with all-cause and cardiovascular mortality in HD patients.

Mean platelet volume and coronary artery disease

PURPOSE OF REVIEW

To critically review the literature describing links between mean platelet volume (MPV) and cardiovascular disease (CVD). We will focus on coronary artery disease (CAD). The MPV is measured routinely as part of a routine blood count.

RECENT FINDINGS

There is accumulating evidence showing that the MPV may predict CVD, as well as outcomes in patients with CAD. There is also evidence linking MPV and comorbidities (e.g. diabetes mellitus and impaired glycaemic control) that are expected in patients with CAD. The effect on MPV of drugs commonly used to treat CAD has not been clarified, but there is some evidence that they may exert a beneficial effect on the MPV. More specifically, the MPV may predict the effect of antiplatelet drugs (e.g. clopidogrel). There is also evidence relating MPV to stroke, atrial fibrillation, coronary artery ectasia and periprocedural outcomes after percutaneous coronary intervention (PCI).

SUMMARY

Measuring the MPV may prove useful in CVD risk assessment in patients with established CAD or at risk of developing CAD. Overall, there is evidence pointing to the role of MPV as a contributor rather than simple marker of CVD.

Mean platelet volume-to-lymphocyte ratio: a novel marker of poor short- and long-term prognosis in patients with diabetes mellitus and acute myocardial infarction

INTRODUCTION

Platelet activation and hyperreactivity plays a pivotal role in developing intravascular thrombus in ST elevation myocardial infarction (STEMI). Mean platelet volume (MPV), which is readily available in clinical settings, has been linked to poor prognosis following STEMI. Recently, platelet-to-lymphocyte ratio (PLR) has emerged as a new marker of worse outcomes linking inflammation and thrombosis. We investigated the prognostic significance of the new marker, MPVLR, in diabetic patients with STEMI undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 623 patients with diabetes mellitus and STEMI undergoing primary PCI were enrolled and divided based on the median MPVLR on admission into two groups: group 1 (N=266) with an MPVLR ≤4.46 and group 2 (N=257) with an MPVLR >4,46.

RESULTS

Despite similar clinical features patients with elevated MPVLR (group 2) had worse angiographic characteristic suggestive of a higher thrombus burden. In-hospital and one-year mortality was higher in group 2. ROC analysis revealed moderate diagnostic value in predicting in-hospital mortality (adjusted HR 1.13; 95% CI 1.04-1.23; P=0.003; MPVLR cut-off >6.13) similar to that of PLR a good diagnostic value in predicting long-term mortality (adjusted HR 1.52; 95% CI 1.42-1.63; P<0.0001; MPVLR cut-off >5.88) better than that of PLR. MPVLR remained an independent risk factor of early and late mortality.

CONCLUSIONS

To the best of our knowledge, this is the first ever study that has investigated MPVLR. Despite similar clinical characteristics, patients with elevated MPVLR had worse angiographic features which may indicate a greater thrombus burden. Elevated MPVLR is an independent risk factor of early and late mortality following STEMI. In addition, it has similar value to PLR in predicting in-hospital mortality, and a better value than PLR in predicting long-term mortality.

Mean Platelet Volume as a Surrogate Marker for Platelet Activation in Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is associated with a prothrombotic state.

AIM

To study mean platelet volume (MPV) and Platelet Distribution Width (PDW) as markers of platelet activation and their potential association with lung function in patients with recently diagnosed IPF.

MATERIALS AND METHODS

This study included 56 patients with IPF (age 64.9±7.4 years) and 79 controls (age 64.2 ± 5.9 years).

RESULTS

An inverse relation was demonstrated between platelet count and MPV in the control group but not among patients with IPF. Platelet count was significantly lower in patients with IPF compared with controls (230 ± 60 vs 256 ± 75 × 10(3)/μL, P = .038). Conversely, MPV was higher in patients versus controls (10.3 ± 1.2 vs 9.8 ± 1.2 fl, P = .024), while there was no difference between the groups in PDW. Respiratory function was, as expected, significantly impaired in patients with IPF versus controls in terms of forced expiratory volume in first second (FEV1; 67.2 ± 23.1 vs 102.6 ± 15.9% of predicted value, P < .001), forced vital capacity (FVC; 65.3 ± 21 vs 95.2 ± 16.1% of predicted value, P < .001), FEV1/FVC (83.1 ± 15 vs 87.5 ± 6.4%, P = .041) and partial pressure of oxygen in arterial blood (PaO2; 67.1 ± 10.3 vs 81.5 ± 15.2 mm Hg, P < .001). No significant correlation was seen between MPV and FVC (r = -.1497, P = .275), MPV and lung diffusion capacity for carbon monoxide (r = .035, P = .798) and total lung capacity (r = .032, P = .820).

CONCLUSIONS

Patients with IPF exhibit higher MPV values and lower platelet count. Further studies are needed to assess the clinical implications of these findings.

Effects of oral hypoglycemic agents on platelet function

Platelet dysfunction plays a role in diabetic macrovascular complications. Several studies have assessed the effect of oral hypoglycemic agents (OHAs) on platelet function. Data from both in vivo and in vitro studies show a favorable effect for most of the traditional glucose-lowering therapies, while evidence is limited for the newer ones. Metformin, sulfonylureas, glitazones and acarbose exert a favorable effect on platelet function. Among incretin therapies, only sitagliptin has so far been demonstrated to have a beneficial effect on platelet aggregation. More in vivo and in vitro evidence is required to increase our knowledge on any potential beneficial effects of OHAs on platelet function. Any such effect may have implications for the reduction of cardiovascular risk in type 2 diabetes mellitus.