Mean platelet volume is increased in hyperthyroidism

Safety of Aesthetic Medicine Procedures in Patients with Autoimmune Thyroid Disease: A Literature Review

Autoimmune thyroid diseases are the most common organ-specific autoimmune diseases, affecting 2–5% of the world’s population. Due to the autoimmune background of thyroid diseases, we analyzed a wide range of cosmetic procedures, from minimally invasive cosmetic injections (mesotherapy) to highly invasive procedures, such as lifting threads. Out of the seven categories of treatments in aesthetic medicine analyzed by us—hyaluronic acid, botulinum toxin, autologous platelet-rich plasma, autologous fat grafting, lifting threads, IPL and laser treatment and mesotherapy—only two, mesotherapy and lifting threads, are not recommended. This is due to the lack of safety studies and the potential possibility of a higher frequency of side effects in patients with autoimmune thyroid diseases.

Early onset preeclampsia is associated with an elevated mean platelet volume (MPV) and a greater rise in MPV from time of booking compared with pregnant controls: results of the CAPE study

OBJECTIVE

To characterise Mean platelet volume (MPV) in patients with early onset preeclampsia (EOPE) and unaffected controls from time of first antenatal visit until the postpartum.

MATERIALS AND METHODS

Retrospective secondary analysis of an observational study in an Irish tertiary referral centre with 9000 deliveries annually. The MPV of 27 women with EOPE was compared to 19 unaffected controls. The inclusion criteria for the disease state was the development of EOPE defined by the National Institute for Health and Care Excellence (NICE) guideline, as new onset hypertension presenting after 20 weeks and prior to 34 weeks with significant proteinuria. Between October 2013 and July 2015 we recruited 27 women with EOPE and 19 pregnant controls. Statistical analysis was performed using paired T-test of Mann-Whitney test where appropriate and a P-value <0.05 was deemed significant.

RESULTS

At time of diagnosis and late in the third trimester MPV was significantly increased to 9.0 (±0.3) fL in cases of EOPE in comparison to 8.5 (±0.6) fL in normotensive controls (P<0.05). There was no significant difference during the first trimester or postpartum when comparing the MPV in EOPE to controls.

CONCLUSION

Despite an increased MPV at time of diagnosis of EOPE this study did not demonstrate a potential use for increased MPV as a first trimester screening tool.

Relationship Between Thyroid Hormone Levels and Mean Platelet Count and Volume: Quantitative Assessment

Background

The hormones of the hypophysis-thyroid axis (HTA), thyroid stimulating hormone (TSH), and thyroid hormones, L-thyroxine (T4) and 3, 3′, 5-L-triiodothyronine (T3), modulate the metabolism, differentiation, and proliferation of almost every cell in the body. Several studies have examined the effect of HTA hormones on platelet count and mean platelet volume (MPV), but have reported inconsistent results. Our aim was to examine the association between HTA hormones and platelet count and MPV in a large cohort of the adult population of the United States.

Methods 

We used the continuous National Health and Nutritional Examination Survey (NHANES) which made available data on HTA hormones (1999-2000, 2001-2002, 2007-2008, 2009-2010, and 2011-2012) to examine the association between HTA hormones and platelet count and MPV. Analyses were performed with adjustments for the complex survey sampling methods of NHANES data. Unadjusted and adjusted generalized linear regressions were performed to examine the relationship between HTA hormones and platelet count and MPV. Regression models were adjusted for age, sex, race, alcohol use, smoking status, serum c-reactive protein, red blood cell folate, diabetes mellitus, glomerular filtration rate, body mass index, and hypertension.

Results

Of the 10,619 individuals eligible for inclusion in the analyses, 5,267 (49.6%) were females and 2,132 (20.08%) were African Americans. The mean ± standard deviation of platelet count was 256.4 ± 67.1 10⁹/L, MPV 8.04 ± 0.92 fL, serum T4 7.92 ± 1.68 mg/dL, and serum T3 114.08 ± 24.6 ng/dL. In unadjusted analyses, an increase in the serum levels of T4 or T3 was associated with a significant increase in the platelet count and MPV (all p-values < 0.05). In contrast, an increase in serum TSH level was associated with a significant decrease in the platelet count (p-value = 0.05) but had no effect on MPV. After adjustment for potential confounders, serum T4 levels were significantly associated with platelet count but not with MPV. Individuals in the lowest quartile of T4 had 18.73 x 10⁹/L lower platelet count than individuals in the upper-most quartile (p-value = 0.03). Serum TSH and serum T3 levels had no effect on platelet count or MPV after adjusting for potential confounding variables.

Conclusions

We report that only serum T4 levels, and not TSH or T3 levels, are independently associated with platelet count and there is no independent association between HTA hormones and MPV. Our findings suggest a possible role of serum T4 on thrombopoiesis or on platelet lifespan.

No associations exist between mean platelet volume or platelet distribution width and thyroid function in Chinese

Mean platelet volume (MPV) and platelet distribution width (PDW) are morphometric indices of size distribution and variability of platelet. We aimed to explore the associations between MPV or PDW and thyroid function in a large Chinese cohort.This was a cross-sectional study with a recruitment of 13,622 self-reported healthy Chinese (8424 males, 5198 females). Clinical data of the participants comprised of anthropometric measurements, hepatic function, renal function, serum levels of lipid, glucose, C-reactive protein, erythrocyte sedimentation rate, platelet, MPV, PDW, and thyroid hormones. Database was sorted by sex, and the associations between MPV or PDW and thyroid function were analyzed by quartiles of MPV or PDW. Levels of MPV and PDW were compared in different thyroid function subgroups by 1-way analysis of variance and independent sample's t test. Receiver-operating characteristic (ROC) curve was adopted to determine diagnostic values of MPV and PDW for thyroid dysfunction. Crude and adjusted odds ratios of MPV and PDW for thyroid dysfunction with 95% confidence intervals were analyzed by binary logistic regression models.MPV, PDW, and thyroid stimulation hormone were significantly higher in females than in males. Females showed significantly higher incidence of hypothyroidism and hyperthyroidism than males. However, there were no significant differences of MPV and PDW among different thyroid function subgroups in both sexes, and no obvious correlations were revealed between MPV or PDW and thyroid function. From ROC analysis, we demonstrated no diagnostic values of MPV and PDW for thyroid dysfunction. From binary logistic regression models, no risks of different MPV and PDW quartiles were identified for thyroid dysfunction in both sexes.We could not show any association between MPV or PDW and thyroid function. Prospective studies with better defined risk groups should be performed in the future for further verification and validation.

Mean platelet volume is significantly associated with serum levels of thyroid-stimulating hormone in a cohort of older euthyroid subjects

PURPOSE

This retrospective and observational study aimed to establish whether any relationship exists between the values of serum thyroid-stimulating hormone (TSH) and those of the mean platelet volume (MPV) in a large cohort of older euthyroid Italian subjects.

MATERIALS AND METHOD

The study population was represented by a cohort of 1,050 ostensibly healthy and euthyroid patients aged 50 years and older, who were referred for screening of thyroid disorders over a 1-year period.

RESULTS

A significant association was found between MPV and TSH values in both simple (r = 0.12; p < 0.001) and multivariable regression analysis (beta coefficient, 0.07; p < 0.001) after adjustment for age, sex, free thyroxin values and platelet count. After stratification of the study population according to quartiles of serum TSH levels, a graded increase of MPV values was found from the first to the fourth quartile of TSH (p = 0.013). The odds ratio for an increased MPV value of the fourth versus the first quartile of TSH was 1.54 (95% CI, 1.08-2.20; p = 0.017).

CONCLUSIONS

The results of this investigation demonstrate that a significant, positive and independent association exists between MPV and serum TSH values in a large cohort of older euthyroid Italian subjects.

Red cell distribution width is associated with long-term prognosis in patients with stable coronary artery disease

Background

Data regarding the association between red cell distribution width (RDW) values and mortality in patients with stable coronary artery disease are scarce. We aimed to investigate the link between mortality and RDW in patients with stable coronary artery disease undergoing percutaneous coronary intervention (PCI).

Methods

We analyzed 2550 consecutive patients with stable coronary artery disease who underwent PCI between 2007 and 2011 at our institution. The patients were divided into four groups according to RDW quartiles. The association between the RDW values and the outcomes was assessed using Cox proportional regression analysis after adjusting for clinical, echocardiographic, hemodynamic and laboratory data in the whole population and in subgroups stratified by gender, presence of diabetes, anemia or heart failure.

Results

In the entire population, there was a stepwise relationship between RDW intervals and comorbidities. Patients with the highest RDW values were older and more often burdened with diabetes, heart failure and chronic kidney disease. There was an almost 4-fold increase in mortality during an average of 2.5 years of follow-up between the group of patients with RDW values lower than 13.1% (25^th percentile) and the group with RDW values higher than 14.1% (75^th percentile), (4.3% vs. 17.1%, p < 0.0001). After adjusting for the covariates, RDW remained significantly associated with mortality in the whole cohort (HR-1.23 [95% CI (1.13-1.35), p < 0.0001]) and in the subgroups stratified by gender, age (over and under 75 years), presence of anemia, diabetes, heart failure and chronic kidney disease.

Conclusion

Higher RDW values correspond to higher comorbidity burdens and higher mortality. RDW is an independent predictor of mortality in patients with stable coronary artery disease.

Relationship between placental grade and mean platelet volume

This study was performed to investigate the correlation between mean platelet volume, as an indicator of thrombocyte function, and placental grade classified by the Grannum scoring system. Placental sonographic images were graded according to the Grannum scoring system, and synchronous haemogram samples were taken from patients who attended foetal assessments during the second and third trimesters. A total of 75 patients were in their second trimester, and 40 patients were in their third trimester. The relation between week of pregnancy and placental Grannum score was significant (p<0.001); i.e. placental Grannum score increased with gestational age. The association between Grannum score and mean platelet volume was analysed, including trimester and mean platelet volume, by linear regression analysis. The results indicated a distinct trimester-independent correlation between mean platelet volume and Grannum score (partial correlation coefficient=0.455; p<0.001). However, no correlation was observed between Grannum score and gravity (r=0.87; p=0.356), parity (r=0.97; p=0.302) or abortion (r=0.011; p=0.91). The correlation between mean platelet volume and placental calcification was investigated, and mean platelet volume in patients with a calcified placenta was 8.23 ± 1.14, whereas mean platelet volume in placentas with no calcification was 7.92 ± 1.18 (p=0.233). Mean platelet volume was an independent indicator of Grannum score, which is an indicator of placental grade, in women in the second and third trimester of pregnancy. Assessing mean platelet volume during routine screening may identify functional placental disorders.

Thyroid, hemostasis and thrombosis

The aim of this paper is to briefly review some practical aspects of the relationship between thyroid function and several disorders of the hemostatic system in terms of bleeding and thrombosis. Thrombocytopenia, acquired hemophilia, hypercoagulability, cardioembolism and other biochemical coagulative and fibrinolytic abnormalities have been described in the past years both in hyper- and hypothyroidism. Since most of hyper- and hypothyroid conditions are the consequence of autoimmune thyroid disease (1), either deranged immune function, altered circulating thyroid hormone concentration, or both may concur in the pathogenesis of hemostatic disorders of potential crucial clinical impact. These aspects will be outlined and discussed in an attempt to give answers to some questions, often arising in the clinical approach.

Elevated numbers of reticulated platelets in hyperthyroidism: direct evidence for an increase of thrombopoiesis

We studied thrombopoietic activity in hyperthyroidism by determination of reticulated platelet counts. At the time of hyperthyroidism 14/15 patients had higher reticulated platelets than after achievement of euthyroidism (P<0.001). There was no difference in peripheral platelet counts and mean platelet volumes at the time of hyperthyroidism when compared to euthyroidism. Three patients had pan- and auto-reactive platelet antibodies during hyperthyroidism. These antibodies were directed against GPIIb/IIIa in two patients and against GPIb/IX in one patient. Our findings provide direct evidence that hyperthyroidism is associated with increased platelet production, as reflected by an increase in reticulated platelets.

Platelet volume: laboratory measurement and clinical application

Modern cell analyzers routinely produce platelet indices, but many clinicians do not utilize them in clinical decision-making. In part this can be attributed to difficulties with their laboratory measurement. The mean platelet volume is dependent on a number of variables, including time of analysis after venepuncture, method of analysis, anticoagulant used and specimen storage temperature. The influence of these laboratory variables is significant and reproducible mean platelet volumes are dependent on standardized laboratory methodology. When pre-analysis factors are controlled, alterations in platelet volume can be demonstrated in a number of disease states and assessment of platelet volume can be useful in the monitoring and diagnosis of patients. An understanding of the pathophysiology of alterations in platelet volume and of the inverse relationship between platelet volume and count is a prerequisite for the successful clinical application of platelet volume measurements.

Familial association of autoimmune thrombocytopenia and hyperthyroidism

An association between thrombocytopenia and thyrotoxicosis in a single individual is well documented, and the theories for this event include a common immunologic cause or a thyrotoxic-induced decrease in platelet survival. We report the first description of the coexistence of autoimmune thrombocytopenic purpura (AITP) and Graves' disease in several members of the same family, in which four females were thrombocytopenic and two of these were also hyperthyroid. All four patients had high titers of antiplatelet antibodies, and the two hyperthyroid cases were positive for thyroid-stimulating immunoglobulins (TSI). The familial occurrence of two autoimmune disorders is very uncommon, and suggests a genetic etiology. The HLA phenotype was determined and the antigens B8 and DR3, which are reported with high frequency in both diseases, were present in three patients. Although the etiologic cause is still unknown, our findings further support the theory that a genetic predisposition underlies autoimmune disease.

Haemostasis in hypothyroidism

Abnormalities that have been reported for platelet indices and function, coagulation factors and tests, and the fibrinolytic system in hypothyroidism are reviewed. These abnormalities, although usually of limited importance clinically, may occasionally lead to major bleeding episodes and to diagnostic confusion.