Effect of smoking on platelet count and platelet parameters: an observation

Comparative assessment of individual RONS in serum of smokers compared with non-smokers and their correlation with the lipid profile and antioxidant status

Objective

Cigarette smoking generates free radicals, such as reactive oxygen and nitrogen species (RONS) that contribute to many diseases. The aim of this study was to compare the levels of individual RONS in serum from smokers and non-smokers, and to examine their impact on lipid profiles and the endogenous antioxidant status, which is represented by vitamins C and E.

Methods

Ninety-four healthy Egyptian volunteers (48 smokers and 46 non-smokers) were enrolled. Blood samples were collected and analysed for common haematological tests, lipid profiles, and serum antioxidants. Six reactive oxygen species and three reactive nitrogen species were measured.

Results

A significant increase in radical levels was observed, as well as significant increases in haemoglobin (Hb), haematocrit, platelet count, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol in smokers compared with non-smokers. In contrast, high-density lipoprotein cholesterol was significantly reduced in smokers compared with non-smokers. A moderate negative correlation was found between serum levels of vitamins C and E and O₂^–•, HO^•, H₂O₂, NO^•, and ONO^•, reflecting a negative impact of elevated RONS levels on the endogenous antioxidant status.

Conclusion

These results may increase our understanding of the pathological role of smoking in several diseases.

Smoking and Increased White and Red Blood Cells

Objective—

Whether tobacco smoking causally affects white and red blood cells and thrombocyte counts is unknown. Using a Mendelian randomization approach, we tested the hypothesis that smoking causes increases in these blood cell indices.

Approach and Results—

We included 104 607 white Danes aged 20 to 100 years from the Copenhagen General Population Study with information on blood cell indices, smoking habits, and CHRNA3 (alpha 3 nicotinic cholinergic receptor) rs1051730 genotype, where the T allele causes higher tobacco consumption; 41 759 were former smokers and 17 852 current smokers. In multivariable adjusted observational analyses and compared with never smokers, white blood cells were associated with up to 19% increases, thrombocytes with up to 4.7% increases, and red blood cell indices with up to 2.3% increases in former and current smokers. All associations were dose dependent, with tobacco consumption but for white blood cells and thrombocytes also dependent on smoking cessation time in former smokers; highest increases were for <1-year smoking cessation and lowest increases for >10-year smoking cessation. In age- and sex-adjusted genetic analyses, percent differences per T allele increase in current smokers were 1.15% (95% CI, 0.61%–1.68%) for leukocytes, 1.07% (0.38%–1.76%) for neutrophils, 1.34% (0.66%–2.02%) for lymphocytes, 1.50% (0.83%–2.18%) for monocytes, −0.60% (−1.91% to 0.74%) for eosinophils, 0.17% (−0.94% to 1.29%) for basophils, 0.38% (−0.17% to 0.93%) for thrombocytes, 0.04% (−0.14% to 0.23%) for erythrocytes, 0.34% (0.17% to 0.50%) for hematocrit, 0.26% (0.09% to 0.43%) for hemoglobin, and 0.29% (0.18% to 0.41%) for mean corpuscular volume.

Conclusions—

Smoking causes increased blood leukocytes, neutrophils, lymphocytes, and monocytes, as well as increased hematocrit, hemoglobin, and mean corpuscular volume. The observational smoking relationships were long term for white blood cells and short term for red blood cell indices.

Chronic Obstructive Pulmonary Disease and Platelet Count

Recently, it has been shown in the murine model that platelet maturation takes place, to some extent, in the lungs. The extrapolation of these findings to humans leads to the possibility that chronic lung diseases could affect platelet maturation and, consequently, the platelet count. The aim of this study was to investigate whether there are changes in the platelet count in patients with chronic obstructive disease (COPD). The study included 44 patients, aged 66.5 ± 5.5 years, in stage II-IV COPD. The control group consisted of 48 age- and gender-matched patients without any respiratory diseases. We failed to find a significant difference in the platelet count between the two groups: 231 ± 80 vs. 223 ± 63 x 10³/μL, respectively (p = 0.61). However, the number of platelets in the COPD patients was inversely associated with hemoglobin content (r = -0.57; p < 0.001), hematocrit (r = -0.40; p = 0.006), and the red cell count (r = -0.51; p < 0.001); the blood morphology indices that are typically increased in severe COPD. Such associations were absent in the control non-COPD group. We conclude that COPD has no influence on the platelet count in humans.

Short-Term E-Cigarette Exposure Increases the Risk of Thrombogenesis and Enhances Platelet Function in Mice

Background

Cardiovascular disease is the main cause of death in the United States, with smoking being the primary preventable cause of premature death, and thrombosis being the main mechanism of cardiovascular mortality in smokers. Due to the perception that electronic/e‐cigarettes are “safer/less harmful” than conventional cigarettes, their usage—among a variety of ages—has increased tremendously during the past decade. Notably, there are limited studies regarding the negative effects of e‐cigarettes on the cardiovascular system, which is also the subject of significant debate.

Methods and Results

We employed a passive e‐Vape^TM vapor inhalation system and developed an in vivo whole‐body e‐cigarette mouse exposure protocol that mimics real‐life human exposure scenarios/conditions and investigated the effects of e‐cigarettes and clean air on platelet function and thrombogenesis. Our results show that platelets from e‐cigarette–exposed mice are hyperactive, with enhanced aggregation, dense and α granule secretion, activation of the αIIbβ3 integrin, phosphatidylserine expression, and Akt and ERK activation, when compared with clean air–exposed platelets. E‐cigarette–exposed platelets were also found to be resistant to inhibition by prostacyclin, relative to clean air. Furthermore, the e‐cigarette–exposed mice exhibited a shortened thrombosis occlusion and bleeding times.

Conclusions

Taken together, our data demonstrate for the first time that e‐cigarettes alter physiological hemostasis and increase the risk of thrombogenic events. This is attributable, at least in part, to the hyperactive state of platelets. Thus, the negative health consequences of e‐cigarette exposure should not be underestimated and warrant further investigation.

Lead exposure is associated with risk of impaired coagulation in preschool children from an e-waste recycling area

Environmental lead exposure leads to various deleterious effects on multiple organs and systems, including the hematopoietic system. To explore the effects of lead exposure on platelet indices in preschool children from an informal, lead-contaminated electronic waste (e-waste) recycling area, we collected venous blood samples from 466 preschool children (331 from an e-waste area (Guiyu) and 135 from a non-e-waste area (Haojiang)). Child blood lead levels (BLLs) were determined by graphite furnace atomic absorption spectrophotometry, while platelet indices were quantified using a Sysmex XT-1800i hematology analyzer. Higher blood lead levels are observed in e-waste lead-exposed preschool children. Significant relationships between high blood lead levels (exceeding current health limits) and elevated platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV), and platelet large cell ratio (P-LCR) were also uncovered. Furthermore, the median PLT and PCT levels of children from the exposed group both exceeded the respective recommended maximum reference range value, whereas the reference group did not. Location of child residence in Guiyu and BLLs were both risk factors related to platelet indices. These results suggest that high blood lead exposure from e-waste recycling may increase the risk of an amplified coagulation process through the activation of platelets in preschool children.

Association of thrombocytosis with COPD morbidity: the SPIROMICS and COPDGene cohorts

BACKGROUND

Thrombocytosis has been associated with COPD prevalence and increased all-cause mortality in patients with acute exacerbation of COPD (AECOPD); but whether it is associated with morbidity in stable COPD is unknown. This study aims to determine the association of thrombocytosis with COPD morbidity including reported AECOPD, respiratory symptoms and exercise capacity.

METHODS

Participants with COPD were included from two multi-center observational studies (SPIROMICS and COPDGene). Cross-sectional associations of thrombocytosis (platelet count ≥350 × 10⁹/L) with AECOPD during prior year (none vs. any), exertional dyspnea (modified Medical Research Council (mMRC) score ≥ 2), COPD Assessment Test (CAT) score ≥ 10, six-minute-walk distance (6MWD), and St. George Respiratory questionnaire (SGRQ) were modeled using multivariable logistic or linear regression. A pooled effect estimate for thrombocytosis was produced using meta-analysis of data from both studies.

RESULTS

Thrombocytosis was present in 124/1820 (6.8%) SPIROMICS participants and 111/2185 (5.1%) COPDGene participants. In meta-analysis thrombocytosis was associated with any AECOPD (adjusted odds ratio [aOR] 1.5; 95% confidence interval [95% CI]: 1.1-2.0), severe AECOPD (aOR 1.5; 95% CI: 1.1-2.2), dyspnea (mMRC ≥ 2 aOR 1.4; 95% CI: 1.0-1.9), respiratory symptoms (CAT ≥ 10 aOR 1.6; 95% CI: 1.1-2.4), and higher SGRQ score (β 2.7; 95% CI: 0.5, 5). Thrombocytosis was also associated with classification into Global Initiative for Chronic Obstructive Lung Disease (GOLD) group D (aOR 1.7 95% CI: 1.2-2.4).

CONCLUSIONS

Thrombocytosis was associated with higher likelihood of prior exacerbation and worse symptoms. Platelet count, a commonly measured clinical assay, may be a biomarker for moderate-severe COPD symptoms, guide disease classification and intensity of treatment. Future longitudinal studies investigating the role of platelets in COPD progression may be warranted.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01969344 (SPIROMICS) and NCT00608764 (COPDGene).

Causes of variation in the neutrophil-lymphocyte and platelet-lymphocyte ratios: a twin-family study

AIM

Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are biomarkers for disease development, for whom little is known about causes of variation in the general population.

MATERIALS & METHODS

We estimated the heritability of PLR and NLR and examined their association with gender, demographic, lifestyle and environmental factors in a Dutch nonpatient twin family population (n = 8108).

RESULTS

Heritability was estimated at 64% for PLR and 36% for NLR. Men had on average higher NLR, but lower PLR levels than women. PLR and NLR increased significantly with age, decreased in colder months and showed small but significant sex- and age-specific associations with body composition and smoking.

CONCLUSION

NLR and PLR levels are heritable and influenced by age, sex and environmental factors, such as seasonal conditions and lifestyle.

Do circulating blood cell types correlate with modifiable risk factors and outcomes in patients with acute coronary syndrome (ACS)?

AIMS

Atherosclerosis is an inflammatory process with different cardiovascular risk factors (CVRFs) contributing to its pathogenesis. We aimed to evaluate the specific relationship between circulating blood leukocytes, troponin I and CVRFs.

METHODS

We prospectively enrolled 959 patients with evidence of acute coronary syndrome either in form of unstable angina or STEMI or NSTEMI. Details demographic characteristics, CVRF and biochemical parameters such as total white blood cells (WBC), neutrophil, lymphocytes, platelet, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and troponin I were collected.

RESULTS

The results indicated that patients having either hypertension, diabetes or smoking habit had significantly higher levels of total WBC (p=0.013), neutrophil (p=0.029), NLR (p=0.029) and PLR (p=0.009). The level of troponin I was unaffected by these risk factors. Significant association of hypertension was found with total WBC (p=0.0392), lymphocytes (p=0.0384) and PLR (p=0.0027), whereas in diabetes and females all other leukocyte subtypes were significantly altered except for platelet and troponin I. Smokers had higher level of total WBC count (p=0.0033) and PLR (p=0.0464). No relationship between CVRFs and leukocytes was observed in males. The age independent effect was observed with PLR, whereas association with total WBC, lymphocytes, NLR, platelet was specific in older population. In younger patients NLR (p=0.0453) is more likely to be elevated. Mortality was significantly associated with changes in the leukocytes but not with the CVRF presence.

CONCLUSION

We demonstrate that the neutrophils, lymphocytes and total WBC along with its ratios predict mortality and are more likely to be elevated in presence of CVRFs.

Cardiovascular correlates of platelet count and volume in the Framingham Heart Study

PURPOSE

Platelet count and volume are inexpensive, routinely assayed biomarkers associated with cardiovascular health, but specific relationships among platelet indices, cardiovascular risk factors, and disease warrant further investigation. The purpose of this study was to understand associations among platelet count, volume, and 20 cardiovascular health-related variables in the Framingham Heart Study (FHS).

METHODS

Cross-sectional analyses were performed on platelet count and volume associations with cardiovascular health indicators in three FHS cohorts (original n = 964, offspring n = 2699, and third generation n = 2419) using multivariate linear regression analysis. Time-to-event analysis was used for cardiovascular disease-related event incidences using Kaplan-Meier plots and Cox proportional hazards regression adjusted for age and sex.

RESULTS

Results were concordant with the hypothesis that higher platelet counts are associated with less favorable cardiovascular risk profiles, although mean platelet volume associations were weaker. In our analysis, increased platelet count across FHS cohorts was consistently associated with smoking, triglycerides, low-density lipoprotein, and total cholesterol levels. Some associations with platelet count appeared sex dependent.

CONCLUSIONS

Significant associations of common blood platelet measurements are observed with sex and cardiovascular risk factors, namely smoking and lipids. Research is warranted to confirm these relationships in other cohorts, evaluate differences by ethnicity, and examine longitudinal effects on disease risk.

"Smoker's Paradox" in Patients Treated for Severe Injuries: Lower Risk of Mortality After Trauma Observed in Current Smokers

BACKGROUND

Studies evaluating the effect of smoking status on mortality outcomes in trauma patients have been limited, despite the fact that survival benefits of smoking have been reported in other critical care settings. The phenomenon "smoker's paradox" refers to the observation that following acute cardiovascular events, such as acute myocardial infarction and cardiac arrest, smokers often experience decreased mortality in the hospital setting. The objective of our study was to determine whether smoking imparts a survival benefit in patients with traumatic injuries.

METHODS

We performed a retrospective cohort study that analyzed cases included in the National Trauma Data Bank research dataset. Hierarchical logistic regression analyses were used to determine whether smoking alters the risk of mortality and complications in patients who smoke.

RESULTS

The percentage of patients experiencing mortality differed significantly between smokers (n = 38,564) and nonsmokers (n = 319,249) (1.8% vs. 4.3%, P < .001); however, the percentage experiencing a major complication did not (9.7% vs. 9.6%, P = .763). Regression analyses indicated that smokers were significantly less likely to die during the hospital stay compared to nonsmokers after adjusting for individual and hospital factors (OR = 0.15; CI = 0.10, 0.22). Additionally, smokers were also less likely to develop a major complication than nonsmokers (OR = 0.73, CI = 0.59-0.91).

CONCLUSIONS

Patients who smoke appear to have a much lower risk of in-hospital mortality than nonsmokers. Further investigation into biological mechanisms responsible for this effect should be carried out in order to potentially develop therapeutic applications.

Effects of lead exposure on the status of platelet indices in workers involved in a lead-acid battery manufacturing plant

This study was carried out to determine the effect of Pb exposure on the status of platelet indices in workers exposed to Pb during lead-acid battery plant process. Platelet indices and blood lead levels (BLLs) were determined in 429 male workers. BLLs were determined by using an atomic absorption spectrophotometer. Platelet indices in the samples were quantified by using the Sysmex KX-21 hematology analyzer. The levels of platelet count (PLT), plateletcrit (PCT) and mean platelet mass (MPM) were significantly decreased and platelet distribution width (PDW), platelet large cell ratio (P-LCR) and mean platelet volume were increased with an increase in BLLs. The results of linear multiple regression analysis showed that the platelet count (β -0.143, P=0.005), PCT (β -0.115, P=0.023) and MPM (β -0.110, P=0.030) were negatively associated with BLLs and P-LCR (β 0.122, P=0.016) was positively associated with BLLs. The variable of body mass index showed a positive association with PCT (β 0.105, P=0.032) and MPM (β 0.101, P=0.039). The results of the study may indicate that lead exposure may impair coagulation function through endothelial tissue injury and reduction of nitric oxide.

A disease-specific activity score for Thromboangiitis obliterans

INTRODUCTION

The aim of this study was to find a disease-specific activity score for Thromboangiitis obliterans (TAO).

METHODS

About 173 admission records from 125 patients with TAO over the period 2005-2011 were evaluated. The outcome of the patients was categorized as saved-limb or limb-loss. The risk of limb loss associated with each clinical sign or symptom and complete blood count (CBC) data were then assessed. This risk assessment value was multiplied by 100 to obtain the percentage risk, which was then considered to be the risk score. The receiver operating characteristic (ROC) curve was used for demonstrating cut-offs for each score. The reliability of the risk score was evaluated using a split-half reliability test. The divergent validity of the risk score was tested using the Pearson correlation coefficient between the total scores of the patients with and without limb loss.

RESULTS

The maximum possible clinical and CBC scores were 221 and 180, respectively, giving a maximum total score of 401. The cut-offs for clinical, laboratory and total score were 115, 75 and 213, respectively.

CONCLUSION

Further cohort studies for evaluating the efficacy of different treatments for limb salvage of TAO patients based on these score are suggested.

Diagnostic accuracy of mean platelet volume in thromboangiitis obliterans

Thromboangiitis obliterans (TAO) affects small- and medium-sized vessels of the extremities via a non-atherosclerotic inflammatory process in the elderly. Although diagnostic criteria have been determined, only a few studies have been described in the laboratory features. Diagnostic biomarkers are important for reducing disruptions caused by TAO. The diagnostic importance of mean platelet volume (MPV) was investigated in TAO patients. Forty-four patients diagnosed with TAO (study group) and 45 healthy individuals (control group) were included in the study. The age, gender and complete blood parameters obtained via peripheral venous blood samples were compared between the two groups. A receiver operating characteristic (ROC) curve was used for determining the diagnostic accuracy of the MPV variable. All the variables were statistically similar in each group except MPV and platelet counts. MPV was significantly higher and platelet count was significantly lower in the TAO group ( P < 0.05). In addition, diagnostic accuracy was measured by the area under the ROC curve (Figure  1 ), and MPV differs significantly ( P < 0.001), with a value of 0.783 (95% CI: 0.711–0.854). This study indicates that MPV is probably an important diagnostic predictor in TAO patients. Detection of blood parameters such as platelet properties is important for meticulous care of these patients. [Figure: see text]

Clustered components of the metabolic syndrome and platelet counts in Japanese females

BACKGROUND

Blood platelet counts (PCs) play a role in the development of cardiovascular disease (CVD). The metabolic syndrome (MS) is also associated with high CVD risk. However, the connection between PCs and MS has not yet been thoroughly investigated in relation to various biosocial factors that can affect both PCs and the pathophysiology of MS.

METHODS

A total of 152 asymptomatic female subjects (mean age 50 years) with almost normal levels of hemoglobin and white blood cell counts were recruited. MS was diagnosed according to the NCEP-ATP III criteria with a minor modification. The relationships between PCs and MS were analyzed according to the number of MS components (0, 1-2, > or =3). Biosocial factors including age and some lifestyle factors (smoking, alcohol intake and physical activity) were included in the analyses.

RESULTS

PCs in subjects with > or =3 MS components (233+/-43 [SD]x10(9) /L) were strikingly and significantly higher than in subjects with 0 (194+/-34 x 10(9)/L) or 1-2 MS components (207+/-38 x 10(9)/L). General linear model analysis for PCs, adjusted for all biosocial factors and number of MS components, revealed a significant and positive correlation between PCs and number of MS components (p<0.0001).

CONCLUSIONS

The results suggest that PCs may be a potential marker associated with clustered MS components, independent of some biosocial factors, in Japanese females.