Effect of Bariatric Surgery-Induced Weight Loss on Platelet Count and Mean Platelet Volume: a 12-Month Follow-Up Study

Role of Platelets in Rheumatic Chronic Autoimmune Inflammatory Diseases

Platelets are essential in maintaining blood homeostasis and regulating several inflammatory processes. They constantly interact with immune cells, have immunoregulatory functions, and can affect, through immunologically active substances, endothelium, leukocytes, and other immune response components. In reverse, inflammatory and immune processes can activate platelets, which might be significant in autoimmune disease progression and arising complications. Thus, considering this interplay, targeting platelet activity may represent a new approach to treatment of autoimmune diseases. This review aims to highlight the role of platelets in the pathogenic mechanisms of the most frequent chronic autoimmune inflammatory diseases to identify gaps in current knowledge and to provide potential new targets for medical interventions.

Effect of laparoscopic sleeve gastrectomy on platelet count and mean platelet volume

Objective

Several studies have reported an increase in platelet (PLT) count with chronic inflammation in the presence of obesity. Mean platelet volume (MPV) is an important marker for PLT activity. Our study aims to demonstrate if laparoscopic sleeve gastrectomy (LSG) has any effect on PLT, MPV and white blood cells (WBCs).

Methods

A total of 202 patients undergoing LSG for morbid obesity between January 2019 and March 2020 who completed at least 1 year of follow-up were included in the study. Patients' characteristics and laboratory parameters were recorded preoperatively and were compared in the 6th and 12th months.

Results

Two hundred and two patients (50% - female) with a mean age of 37.5 ± 12.2 years and mean pre-operative body mass index (BMI) of 43 (34.1-62.5) kg/m2 underwent LSG. BMI regressed to 28.2 ± 4.5 kg/m2 at 1 year after LSG (P < 0.001). The mean PLT count, MPV and WBC during the pre-operative period were 293.2 ± 70.3 103 cells/μL, 10.22 ± 0.9 fL and 7.8 ± 1.9 103 cells/μL, respectively. A significant decrease was seen in mean PLT count, with 257.3 ± 54.2 103cell/μL (P < 0.001) at 1 year post-LSG. The mean MPV was increased at 6 months 10.5 ± 1.2 fL (P < 0.001) and remained unchanged at 1 year 10.3 ± 1.3 fL (P = 0.9). The mean WBC levels were significantly decreased with 6.5 ± 1.7 103 cells/μL (P < 0.001) at 1 year. At the end of the follow-up, weight loss showed no correlation with PLT and MPV (P = 0.42, P = 0.32).

Conclusion

Our study has shown a significant decrease in circulating PLT and WBC levels while MPV remained unchanged after LSG.

Impact of Physical Exercise on Platelets: Focus on Its Effects in Metabolic Chronic Diseases

Chronic disorders are strongly linked to cardiovascular (CV) diseases, and it is unanimously accepted that regular exercise training is a key tool to improving CV risk factors, including diabetes, dyslipidemia, and obesity. Increased oxidative stress due to an imbalance between reactive oxygen species production and their scavenging by endogenous antioxidant capacity is the common ground among these metabolic disorders, and each of them affects platelet function. However, the correction of hyperglycemia in diabetes and lipid profile in dyslipidemia as well as the lowering of body weight in obesity all correlate with amelioration of platelet function. Habitual physical exercise triggers important mechanisms related to the exercise benefits for health improvement and protects against CV events. Platelets play an important role in many physiological and pathophysiological processes, including the development of arterial thrombosis, and physical (in)activity has been shown to interfere with platelet function. Although data reported by studies carried out on this topic show discrepancies, the current knowledge on platelet function affected by exercise mainly depends on the type of applied exercise intensity and whether acute or habitual, strenuous or moderate, thus suggesting that physical activity and exercise intensity may interfere with platelet function differently. Thus, this review is designed to cover the aspects of the relationship between physical exercise and vascular benefits, with an emphasis on the modulation of platelet function, especially in some metabolic diseases.

Effectiveness, safety, and costs of thromboprophylaxis with enoxaparin or unfractionated heparin in inpatients with obesity

Background

Obesity is a frequent and significant risk factor for venous thromboembolism (VTE) among hospitalized adults. Pharmacologic thromboprophylaxis can help prevent VTE, but real-world effectiveness, safety, and costs among inpatients with obesity are unknown.

Objective

This study aims to compare clinical and economic outcomes among adult medical inpatients with obesity who received thromboprophylaxis with enoxaparin or unfractionated heparin (UFH).

Methods

A retrospective cohort study was performed using the PINC AI™ Healthcare Database, which covers more than 850 hospitals in the United States. Patients included were ≥18 years old, had a primary or secondary discharge diagnosis of obesity [International Classification of Diseases (ICD)-9 diagnosis codes 278.01, 278.02, and 278.03; ICD-10 diagnosis codes E66.0x, E66.1, E66.2, E66.8, and E66.9], received ≥1 thromboprophylactic dose of enoxaparin (≤40 mg/day) or UFH (≤15,000 IU/day) during the index hospitalization, stayed ≥6 days in the hospital, and were discharged between 01 January 2010, and 30 September 2016. We excluded surgical patients, patients with pre-existing VTE, and those who received higher (treatment-level) doses or multiple types of anticoagulants. Multivariable regression models were constructed to compare enoxaparin with UFH based on the incidence of VTE, pulmonary embolism (PE)---------related mortality, overall in-hospital mortality, major bleeding, treatment costs, and total hospitalization costs during the index hospitalization and the 90 days after index discharge (readmission period).

Results

Among 67,193 inpatients who met the selection criteria, 44,367 (66%) and 22,826 (34%) received enoxaparin and UFH, respectively, during their index hospitalization. Demographic, visit-related, clinical, and hospital characteristics differed significantly between groups. Enoxaparin during index hospitalization was associated with 29%, 73%, 30%, and 39% decreases in the adjusted odds of VTE, PE-related mortality, in-hospital mortality, and major bleeding, respectively, compared with UFH (all p < 0.002). Compared with UFH, enoxaparin was associated with significantly lower total hospitalization costs during the index hospitalization and readmission periods.

Conclusions

Among adult inpatients with obesity, primary thromboprophylaxis with enoxaparin compared with UFH was associated with significantly lower risks of in-hospital VTE, major bleeding, PE-related mortality, overall in-hospital mortality, and hospitalization costs.

High visceral fat-to-muscle ratio is an independent factor that predicts worse overall survival in patients with primary epithelial ovarian, fallopian tube, and peritoneal cancer

BACKGROUND

The intra-abdominal cavity, surrounded by adipocytes, is the main metastatic site of epithelial ovarian, fallopian tube, and peritoneal cancer. Epidemiological and molecular studies have demonstrated a link between adipose tissue and ovarian cancer. However, the clinical significance of fatty tissue has not been elucidated. Thus, we investigated the clinical significance of body composition in patients with epithelial ovarian, fallopian tube, and peritoneal cancer.

METHODS

Fat and skeletal muscle areas were measured using software based on pretreatment computed tomography scans at the third lumbar vertebra. Fat-to-muscle ratios were calculated using the total (visceral and subcutaneous) fat area or visceral fat area. High fat-to-muscle ratios were defined by values greater than the mean. Sarcopenia was defined as a skeletal muscle index < 38.7 cm²/m². The clinicopathological parameters and survival of 153 patients were analyzed.

RESULTS

High visceral fat-to-muscle ratios and sarcopenia at the time of diagnosis were observed in 43.8% and 33.3% of the patients, respectively. Multivariate analysis showed that high visceral fat-to-muscle ratio (p = 0.014), advanced Federation of Gynecology and Obstetrics stage (p = 0.008), and chemoresistance (p = 0.027) were independent factors for worse overall survival. Patients with high visceral fat-to-muscle ratios were older, had higher body mass indexes, and were more likely to have diabetes/hypertension, serous cancer subtypes, and implementation of neoadjuvant chemotherapy than those with low visceral fat-to-muscle ratios. The platelet count was significantly higher in the high visceral fat-to-muscle ratio group than in the low visceral fat-to-muscle ratio group (p = 0.011).

CONCLUSIONS

Pretreatment visceral fat area could be an independent predictive factor of overall survival in patients with epithelial ovarian, fallopian tube, and peritoneal cancer and may be significantly associated with thrombocytosis.

Transcriptional, epigenetic and metabolic signatures in cardiometabolic syndrome defined by extreme phenotypes

BACKGROUND

This work is aimed at improving the understanding of cardiometabolic syndrome pathophysiology and its relationship with thrombosis by generating a multi-omic disease signature.

METHODS/RESULTS

We combined classic plasma biochemistry and plasma biomarkers with the transcriptional and epigenetic characterisation of cell types involved in thrombosis, obtained from two extreme phenotype groups (morbidly obese and lipodystrophy) and lean individuals to identify the molecular mechanisms at play, highlighting patterns of abnormal activation in innate immune phagocytic cells. Our analyses showed that extreme phenotype groups could be distinguished from lean individuals, and from each other, across all data layers. The characterisation of the same obese group, 6 months after bariatric surgery, revealed the loss of the abnormal activation of innate immune cells previously observed. However, rather than reverting to the gene expression landscape of lean individuals, this occurred via the establishment of novel gene expression landscapes. NETosis and its control mechanisms emerge amongst the pathways that show an improvement after surgical intervention.

CONCLUSIONS

We showed that the morbidly obese and lipodystrophy groups, despite some differences, shared a common cardiometabolic syndrome signature. We also showed that this could be used to discriminate, amongst the normal population, those individuals with a higher likelihood of presenting with the disease, even when not displaying the classic features.

Associations of urinary dichloroacetic acid and trichloroacetic acid exposure with platelet indices: Exploring the mediating role of blood pressure in the general population

Human exposure to drinking water disinfection by-products (DBPs) is potentially linked to high blood pressure (BP), which may be associated with abnormal platelet activation. This study investigated whether the relationship between DBP exposure with platelet change was mediated by BP. DBP biomarkers, such as urinary dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), BP and platelet indices from 505 adults from a hospital in Shijiazhuang, China were measured. The cross-sectional associations among DCAA and TCAA exposure, BP and platelet indices were explored through multivariable linear regressions, and the mediation effect of BP was evaluated using the Sobel-Goodman test. We observed that DCAA and TCAA were positively associated with systolic BP (all p for trends < 0.01), which was positively associated with platelet count (PLC) (p for trend < 0.05). Mediation analysis indicated that systolic BP fully mediated the associations of DCAA and TCAA with PLC. When BP was controlled, a previously inverse significant relation between DCAA and platelet distribution width (PDW) remained significant (p < 0.05). Obtained results suggested that exposure to DCAA may contribute to decreased PDW in humans. Systolic BP is a possible mediator of the association between DCAA exposure and PLC. TCAA may indirectly positively affect PLC by increasing systolic BP.

The hematologic consequences of obesity

The prevalence of obesity is increasing and progressively influencing physician-patient interactions. While there is a sizable amount of data demonstrating that obesity is a state of low-grade inflammation, to our knowledge, there is no single review summarizing its effects on hematologic parameters and thrombotic risk. We performed a literature search which largely surfaced observational studies, with a few systematic reviews and meta-analyses of these studies. We took care to review the mechanisms driving an inflammatory state and obesity's effect on white blood cells, red blood cells, platelets, and thrombotic risk. There is an observed relative, and sometimes absolute leukocytosis driven by this inflammatory state. Obesity is also associated with increased platelet counts and an increased risk for venous thromboembolism (VTE). Lastly, the association between obesity, iron deficiency (ID), and red blood cell counts may be present but remains uncertain. Recognizing the above associations may provide clinicians with reassurance regarding otherwise unexplained hematologic abnormalities in obese individuals. We hope this review will prompt future studies to further understand the underlying mechanisms driving these abnormalities and identify modifiable risk factors and potential therapeutic targets to prevent the development of probable obesity-associated conditions with significant morbidity and mortality, such as ID and VTE.

Short-term multiorgan metabolic benefits of rapid weight loss after sleeve gastrectomy in severely obese patients

BACKGROUND

Sleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective.

OBJECTIVE

Comprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG.

SETTING

Academic hospital, United States.

METHODS

We retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up.

RESULTS

A total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein.

CONCLUSION

There are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy.

Analysis of platelets from a diet-induced obesity rat model: elucidating platelet dysfunction in obesity

Obesity is one of the main health problems in industrialized countries. The contribution of multiple factors developed in obesity can hardly be modeled in vitro. In this context, the development of animal models mimicking human obesity could be essential. The aim of the present study was to compare platelets from a diet-induced obesity (DIO) rat model with their lean control group in order to elucidate platelet dysfunction mechanisms in obesity and correlate the results with previous data from morbid obese patients. In parallel, we also established a blood collection and platelet isolation methodology to study the DIO rat model at biochemical and functional level. Optimal blood collection was obtained from vena cava and platelet isolation was based on a serial of centrifugations avoiding platelet activation. Our results show that the DIO rat model simulate obesity pathologically since weight gain, fasting glucose and platelet counts are increased in obese rats. Interestingly, platelet levels of the active form of Src (pTyr⁴¹⁹) showed a tendency to increase in DIO rats pointing towards a potential dysfunction in Src family kinases-related signalling pathways in obesity. Moreover, platelets from DIO rats adhere more to collagen compared with the control group, pointing towards Glycoprotein VI (GPVI) as one of the dysregulated receptors in obesity, in agreement with our recent studies in humans. These results confirm that obesity, in line with human studies, present a platelet dysregulation, and highlight the relevance of considering novel antithrombotic drug targets in these patients, such as GPVI.

Influence of Cardiometabolic Risk Factors on Platelet Function

Platelets are key players in the thrombotic processes. The alterations of platelet function due to the occurrence of metabolic disorders contribute to an increased trend to thrombus formation and arterial occlusion, thus playing a major role in the increased risk of atherothrombotic events in patients with cardiometabolic risk factors. Several lines of evidence strongly correlate metabolic disorders such as obesity, a classical condition of insulin resistance, dyslipidemia, and impaired glucose homeostasis with cardiovascular diseases. The presence of these clinical features together with hypertension and disturbed microhemorrheology are responsible for the prothrombotic tendency due, at least partially, to platelet hyperaggregability and hyperactivation. A number of clinical platelet markers are elevated in obese and type 2 diabetes (T2DM) patients, including the mean platelet volume, circulating levels of platelet microparticles, oxidation products, platelet-derived soluble P-selectin and CD40L, thus contributing to an intersection between obesity, inflammation, and thrombosis. In subjects with insulin resistance and T2DM some defects depend on a reduced sensitivity to mediators—such as nitric oxide and prostacyclin—playing a physiological role in the control of platelet aggregability. Furthermore, other alterations occur only in relation to hyperglycemia. In this review, the main cardiometabolic risk factors, all components of metabolic syndrome involved in the prothrombotic tendency, will be taken into account considering some of the mechanisms involved in the alterations of platelet function resulting in platelet hyperactivation.

Platelet-to-lymphocyte ratio (PLR) and Plateletcrit (PCT) in young patients with morbid obesity

OBJECTIVE

To compare the complete blood counts, namely the plateletcrit (PCT) and Platelet-To-Lymphocyte Ratio (PLR) of healthy subjects and those with morbid obesity in the young population.

METHODS

We included 45 patients with morbid obesity (body mass index -BMI - greater than or equal to 45 kg/m2) and 45 healthy subjects (BMI less than or equal to 25 kg/m2) in our study. Blood samples were obtained from the participants following a 12-hour fasting period. Then we evaluated the levels of hemoglobin (Hb), hematocrit (HCT), red cell distribution width (RDW), mean platelet volume (MPV), white blood cell (WBC), PLR, platelet counts, and PCT in the complete blood count.

RESULTS

The morbid obesity group had significantly higher platelet counts and PCT values (p<0.001), and PLR values (p=0.033). The value of WBC was also higher in the obese group (p=0.001). MPV was lower in the obesity group but not statistically significant (p=0.815). No significant difference was found between hemoglobin and hematocrit values in these groups; but RDW valuewere higher and statistically significant in the obese group (p=0.001).

CONCLUSION

PLR or PCT may be more useful as a marker in determining an increased thrombotic state and inflammatory response in morbid obesity.

Platelet Counts and Liver Enzymes After Gastric Bypass Surgery

Background

Obesity is associated with chronic inflammation, liver steatosis and increased liver enzymes such as gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT), markers for non-alcoholic fatty liver disease (NAFLD) and liver fat content. Increased platelet counts (PCs) are a biomarker reflecting inflammation and the degree of fibrosis in NAFLD. We investigated alterations in PCs, GGT, ALT, C-reactive protein (CRP) and ferritin after Roux-en-Y gastric bypass (RYGBP).

Methods

One hundred twenty-four morbidly obese non-diabetic patients were evaluated before (baseline) and 12 months after (follow-up) RYGBP.

Results

Body mass index (BMI) was reduced from 43.5 kg/m² (baseline) to 31.1 kg/m² (follow-up), and p < 0.001 and weight declined from 126.2 to 89.0 kg. PCs decreased from 303 × 10⁹ to 260 × 10⁹/l, p < 0.001. GGT was reduced from 0.63 to 0.38 μkat/l, p < 0.001. ALT decreased from 0.69 to 0.59 μkat/l, p = 0.006. CRP was lowered from 7.3 to 5.4 mg/l p < 0.001 and ferritin from 106 to 84 μg/l p < 0.001. The alterations in PCs correlated with the changes in CRP (r = 0.38, p = 0.001), BMI (r = 0.25, p = 0.012), weight (r = 0.24, p = 0.015) and inversely correlated with ferritin (r = 21, p = 0.036).

Conclusions

PCs, GGT and ALT (markers for NAFLD), and CRP and ferritin (markers for inflammation) decreased in morbidly obese after RYGBP. The decrease in PCs correlated with alterations in CRP, BMI, weight and ferritin. The lowering of liver enzymes may reflect a lowered liver fat content and decreased general inflammation.

Associations of Platelet Indices with Body Fat Mass and Fat Distribution

OBJECTIVE

This study was undertaken to investigate the associations of platelet indices with body fat, including body fat mass and fat distribution.

METHODS

A total of 3,327 individuals aged 18 to 80 were enrolled. Body fat was assessed by dual-energy x-ray absorptiometry. Blood samples were collected to measure platelet indices (platelet count [PLT], plateletcrit [PCT], mean platelet volume, platelet distribution width, and platelet large cell ratio). Adjusted multivariate linear regression models were used to identify the associations of platelet indices with body fat.

RESULTS

PLT was positively associated with BMI, waist circumference, waist-hip ratio, total fat mass percentage, trunk fat mass percentage, android fat mass percentage, and android to gynoid fat ratio but negatively associated with gynoid fat mass percentage, total lean mass percentage, and skeletal muscle mass index. Similar associations were found between PCT and body fat. However, no significant associations were found between the other three platelet indices and body fat.

CONCLUSIONS

Both PLT and PCT were associated with body fat, and the associations depended on fat location. Because PCT is mainly influenced by PLT, these associations suggest that platelet quantity is more closely related to body fat mass and fat distribution.