Weight Change and Risk of Venous Thromboembolism: The Tromsø Study

Venous thrombosis and obesity: from clinical needs to therapeutic challenges

Weight bias and stigma have limited the awareness of the systemic consequences related to obesity. As the narrative evolves, obesity is emerging as a driver and enhancer of many pathological conditions. Among these, the risk of venous thromboembolism (VTE) is a critical concern linked to obesity, ranking as the third most common cardiovascular condition. Obesity is recognized as a multifactorial risk factor for VTE, influenced by genetic, demographic, behavioral, and socio-economic conditions. Despite established links, the exact incidence of obesity related VTE in the general population remains largely unknown. The complexity of distinguishing between provoked and unprovoked VTE, coupled with gaps in obesity definition and assessment still complicates a tailored risk assessment of VTE risk. Obesity reactivity, hypercoagulability, and endothelial dysfunction are driven by the so-called 'adiposopathy'. This state of chronic inflammation and metabolic disturbance amplifies thrombin generation and alters endothelial function, promoting a pro-thrombotic environment. Additionally, the inflammation-induced clot formation-also referred to as 'immunothrombosis' further exacerbates VTE risk in people living with obesity. Furthermore, current evidence highlights significant gaps in the management of obesity related VTE, particularly concerning prophylaxis and treatment efficacy of anticoagulants in people living with obesity. This review underscores the need for tailored therapeutic approaches and well-designed clinical trials to address the unique challenges posed by obesity in VTE prevention and management. Advanced research and innovative strategies are imperative to improve outcomes and reduce the burden of VTE in people living with obesity.

Incidence of Venous Thromboembolism Among Commonly Prescribed Second-Generation Antipsychotics

Background: Second-generation antipsychotics (SGAs) are commonly prescribed medications used to treat a variety of mental health conditions. Recent data has correlated antipsychotic medications with venous thromboembolism (VTE). SGAs have diverse side effect profiles, which may contribute to differences in incidence of VTE. It is unknown which SGAs confer the most risk, and what the mechanism of increased risk is. Objective: Determine incidence of VTE in Veterans at Veterans Affairs North Texas Health Care System (VA-NTX HCS) between SGAs aripiprazole, olanzapine and risperidone. Methods: Retrospective chart review of adult Veterans at VA-NTX HCS between October 2015 to December 2019 prescribed aripiprazole, olanzapine, or risperidone. Results: Of 823 Veterans, incidence of VTE was lowest in aripiprazole group at .4%, increased to 1.7% in the olanzapine group, and was highest at 2.5% in the risperidone group. However, differences in incidence of VTE between SGAs were not statistically different, indicating no between-group differences. Conclusion: There was no difference in the incidence of VTE between risperidone, olanzapine, or aripiprazole. Given multiple limitations with this study, higher-powered studies should be conducted to investigate the possibility of differences in the incidence of VTE between the SGAs.

How I treat the co-occurrence of venous and arterial thromboembolism: anticoagulation, antiplatelet therapy, or both?

ABSTRACT

Arterial and venous thromboses are classically considered distinct disease states, with arterial thrombosis mediated predominantly by platelets and therefore, treated with antiplatelet therapy, and venous thrombosis mediated by the plasmatic coagulation system and treated with anticoagulation. However, co-occurrence of arterial and venous events is common, and there is increasing evidence of shared risk factors and pathophysiologic overlap. This presents a management challenge: does the patient with venous and arterial thrombosis, require anticoagulation, antiplatelet therapy, or both? Herein, we present a structured approach to the evaluation and management of patients with venous thrombosis who are also at risk for or have a history of an arterial thromboembolic event. We emphasize the importance of defining the indications for antithrombotic therapy, as well as the evaluation of factors that influence both thrombotic and bleeding risk, including disorder-specific and patient-specific factors, as well as the inherent risk balance of antithrombotic therapy regimens. We illustrate this approach in 4 cases, discussing the unique considerations and recent updates in the management of venous thrombosis, acute noncardioembolic ischemic stroke, coronary artery disease and acute myocardial infarction, and peripheral artery disease after revascularization.

The Risk of Incident Venous Thromboembolism Attributed to Overweight and Obesity: The Tromsø Study

BACKGROUND

 Obesity is a well-established risk factor for venous thromboembolism (VTE). However, data on the proportion of incident VTEs attributed to overweight and obesity in the general population are limited.

OBJECTIVE

 To investigate the population attributable fraction (PAF) of VTE due to overweight and obesity in a population-based cohort with repeated measurements of body mass index (BMI).

METHODS

 Participants from the fourth to seventh surveys of the Tromsø Study (enrolment: 1994-2016) were followed through 2020, and all incident VTEs were recorded. In total, 36,341 unique participants were included, and BMI measurements were updated for those attending more than one survey. BMI was categorized as <25 kg/m2, 25-30 kg/m2 (overweight), and ≥30 kg/m2 (obesity). Time-varying Cox regression models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). The PAF was estimated based on age- and sex-adjusted HRs and the prevalence of BMI categories in VTE cases.

RESULTS

 At baseline, the prevalence of overweight and obesity was 37.9 and 13.8%, respectively. During a median follow-up of 13.9 years, 1,051 VTEs occurred. The age- and sex-adjusted HRs of VTE were 1.40 (95% CI: 1.21-1.61) for overweight and 1.86 (95% CI: 1.58-2.20) for obesity compared with subjects with BMI <25 kg/m2. The PAF of VTE due to overweight and obesity was 24.6% (95% CI: 16.6-32.9), with 12.9% (95% CI: 6.6-19.0) being attributed to overweight and 11.7% (95% CI: 8.5-14.9) to obesity. Similar PAFs were obtained in analyses stratified by sex and VTE subtypes (provoked/unprovoked events, deep vein thrombosis, pulmonary embolism).

CONCLUSION

 Our findings indicate that almost 25% of all VTE events can be attributed to overweight and obesity in a general population from Norway.

Epidemiology and prevention of venous thromboembolism

Venous thromboembolism, that consists of the interrelated conditions deep-vein thrombosis and pulmonary embolism, is an under-appreciated vascular disease. In Western regions, approximately 1 in 12 individuals will be diagnosed with venous thromboembolism in their lifetime. Rates of venous thromboembolism are lower in Asia, but data from other regions are sparse. Numerous risk factors for venous thromboembolism have been identified, which can be classified as acute or subacute triggers (provoking factors that increase the risk of venous thromboembolism) and basal or acquired risk factors (which can be modifiable or static). Approximately 20% of individuals who have a venous thromboembolism event die within 1 year (although often from the provoking condition), and complications are common among survivors. Fortunately, opportunities exist for primordial prevention (prevention of the development of underlying risk factors), primary prevention (management of risk factors among individuals at high risk of the condition) and secondary prevention (prevention of recurrent events) of venous thromboembolism. In this Review, we describe the epidemiology of venous thromboembolism, including the incidence, risk factors, outcomes and opportunities for prevention. Meaningful health disparities exist in both the incidence and outcomes of venous thromboembolism. We also discuss these disparities as well as opportunities to reduce them.

Fertility, pregnancy and post partum management after bariatric surgery: a narrative review

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Of the women who gave birth in Australia in 2018, 47% had overweight or obesity, with obesity being associated with both maternal and fetal complications.

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Bariatric surgery improves fertility and some pregnancy‐related outcomes.

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Following bariatric surgery, pregnancy should be delayed by at least 12–18 months due to adverse pregnancy outcomes associated with rapid weight loss.

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Contraception should be prescribed after bariatric surgery, although the effectiveness of the oral contraceptive pill may be reduced due to malabsorption and contraceptive devices such as intrauterine devices should be considered as first line therapy.

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After bariatric surgery, women should undergo close monitoring for nutritional insufficiencies before, during and after pregnancy. Expert opinion recommends these women undergo dietary assessment and supplementation to prevent micronutrient deficiencies.

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Bariatric surgeons, bariatric medical practitioners, bariatric dieticians, the patient’s usual general practitioner, obstetricians, and maternity specialists should be involved to assist in the multidisciplinary management of these complex patients.

Risk Factors in Hospitalized Patients for Heparin-Induced Thrombocytopenia by Real World Database: A New Role for Primary Hypercoagulable States

Background

The aims of the study were to identify predictors of heparin-induced thrombocytopenia (HIT) in hospitalized adults, and to find additional factors associated with higher odds of HIT in primary hypercoagulable states.

Methods

A retrospective matched case-control study using discharge data from National Inpatient Sample database (2012 - 2014) was conducted. In primary outcome analysis, hospitalized patients with and without HIT were included as cases and controls, both matched for age and gender. In secondary outcome analysis, hospitalized patients with primary hypercoagulable states with and without HIT were included as cases and controls, both matched for age and gender. The statistical analyses were performed using Statistical Package for Social Sciences version 25.

Results

There are several predictors of HIT in hospitalized patients, such as obesity, malignancy, diabetes, renal failure, major surgery, congestive heart failure, and autoimmune diseases. In patients with primary hypercoagulable states, the presence of renal failure (odds ratio (OR) 2.955, 95% confidence interval (CI) 1.994 - 4.380), major surgery (OR 1.735, 95% CI 1.275 - 2.361), congestive heart failure (OR 4.497, 95% CI 2.466 - 8.202), or autoimmune diseases (OR 1.712, 95% CI 1.120 - 2.618) further increases the odds of HIT.

Conclusions

In hospitalized patients with primary hypercoagulable states, especially in association with renal failure, major surgery, congestive heart failure, or autoimmune diseases, unfractionated heparin should be used with caution.

An investigation of sickle cell trait, body mass index, and fitness in relation to venous thromboembolism among African American adults

BACKGROUND

The relationships of sickle cell trait (SCT), body mass index (BMI), and physical fitness to venous thromboembolism (VTE) in young adults have received little attention.

OBJECTIVES

To test for associations among SCT, BMI, fitness, and VTE.

PATIENTS/METHODS

We conducted a retrospective cohort study of 48,316 SCT-tested, African American individuals in the US Army during 2011-14. We used Cox proportional hazards models to compute adjusted hazards of deep vein thrombosis (DVT) and pulmonary embolism (PE) associated with selected factors.

RESULTS

Incidence rates of DVT and PE were 1.09 and 0.91 cases per 1000 person-years, respectively. Adjusted hazard ratios (aHRs) for DVT for men and women with SCT were 0.9 (95% confidence interval [CI]: 0.4-2.0; P = .711) and 1.51 (CI: 0.7-3.2; P = .274), respectively. aHRs for PE for SCT+ men and women were 1.1 (CI: 0.5-2.4; P = .773) and 1.2 (CI: 0.5-3.1; P = .650), respectively. Low physical fitness was associated with DVT and PE in women (DVT aHR =3.1; CI: 1.4-6.5; P = .004; PE aHR =4.6; CI: 2.1-9.9; P < .001) and DVT in men (aHR =2.2; CI: 1.0-4.6; P = .048). Recent weight gain of 1 or more BMI points was associated with DVT in men (aHR =1.8; CI: 1.1-2.8; P = .017).

CONCLUSIONS

We found no evidence of increased VTE risk associated with SCT in this population. However, lower fitness levels and BMI increases were so associated.

Plasma Levels of Leptin and Risk of Future Incident Venous Thromboembolism

BACKGROUND

 Circulating levels of leptin, an adipocyte-derived hormone, are frequently elevated in obesity. Leptin has been reported to upregulate prothrombotic hemostatic factors in vitro and could potentially mediate venous thromboembolism (VTE) risk in obesity. However, whether leptin is associated with VTE remains uncertain.

OBJECTIVE

 This article investigates the association between plasma leptin and risk of incident VTE, and the potential of leptin to mediate VTE risk in obesity.

METHODS

 A population-based nested case-control study with 416 VTE cases and 848 age- and sex-matched controls was derived from the Tromsø Study. Logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for VTE across leptin quartiles. Analyses were performed separately in men and women using sex-specific quartile cut-offs determined in controls.

RESULTS

 In the age-adjusted model, the VTE risk increased across leptin quartiles, particularly in men. Compared with the lowest quartile, the ORs for VTE in the highest quartile were 1.70 (95% CI 1.04-2.79) in men and 1.36 (95% CI 0.85-2.17) in women. However, with additional adjustment for body mass index (BMI), risk estimates were markedly attenuated in men (OR 1.03, 95% CI 0.55-1.93) and women (OR 0.82, 95% CI 0.45-1.48). The ORs for VTE were increased in obese men and women (BMI ≥ 30 kg/m²) and were only marginally affected after adjustment for leptin.

CONCLUSION

 Our results indicate that the apparent association between plasma leptin levels and VTE risk is confounded by BMI and that leptin is not a relevant mediator for VTE risk in obesity.

Joint Effect of Multiple Prothrombotic Genotypes and Obesity on the Risk of Incident Venous Thromboembolism

BACKGROUND

 The impact of the combination of obesity and multiple prothrombotic genotypes on venous thromboembolism (VTE) risk remains unclear.

OBJECTIVE

 To investigate the joint effect of obesity and a genetic risk score (GRS) composed of established prothrombotic single nucleotide polymorphisms (SNPs) on VTE risk using a population-based case-cohort.

METHODS

 Cases with incident VTE (n = 1,470) and a subcohort (n = 12,826) were derived from the Tromsø Study (1994-2012) and the Trøndelag Health Study (HUNT) (1995-2008). Participants were genotyped for ABO (rs8176719), F5 (rs6025), F2 (rs1799963), FGG (rs2066865), and F11 (rs2036914) SNPs. Age- and sex-adjusted hazard ratios (HRs) were estimated according to body mass index (BMI) categories and number of risk alleles for individual SNPs and the GRS (0-1, 2, 3, ≥4 alleles).

RESULTS

 The combination of obesity (BMI ≥ 30kg/m²) and risk alleles, either as individual SNPs or as a GRS, had an additive effect on VTE risk (i.e., no biological interaction). Obese subjects who were carriers of ≥4 risk alleles had a 2.85-fold (95% confidence interval [CI]: 2.05-3.96) increased risk of overall VTE compared with those with BMI <25 kg/m² and 0 to 1 risk allele. However, in subgroups, the combination of obesity and ≥4 risk alleles was more pronounced for deep vein thrombosis (DVT) (HR: 3.20; 95% CI: 2.09-4.90) and unprovoked VTE (HR: 3.82; 95% CI: 2.25-6.47), suggesting a supra-additive effect.

CONCLUSION

 Our findings indicate that the combination of obesity and GRS has an additive effect on the risk of overall VTE. However, it may have a supra-additive effect on the risk of DVT and unprovoked VTE.

Exploring Opportunities for Primary Prevention of Unprovoked Venous Thromboembolism: Ready for Prime Time?

Venous thromboembolism (VTE) is an important vascular disease and public health problem. Prevention of VTE has focused mainly on using thromboprophylaxis to avoid provoked VTE or recurrent VTE, with little attention paid to the possibility of preventing the one third to one half of VTEs that are unprovoked. We review growing research suggesting that unhealthy lifestyle risk factors may cause a considerable proportion of unprovoked VTE. Using epidemiologic data to calculate population attributable risks, we estimate that in the United States obesity may contribute to 30% of VTEs, physical inactivity to 4%, current smoking to 3%, and Western dietary pattern to 11%. We also review possibilities for VTE primary prevention either through a high-risk individual approach or a population-wide approach. Interventions for outpatients at high VTE risk but without VTE provoking factors have not been fully tested; yet, improving patient awareness of risk and symptoms, lifestyle counseling, and possibly statins or direct oral anticoagulants may prove useful in primary prevention of unprovoked VTE. A population approach to prevention would bolster awareness of VTE and aim to shift lifestyle risk factors downward in the whole population using education, environmental changes, and policy. Assuming the epidemiological associations are accurate, causal, and independent of each other, a reduction of obesity, physical inactivity, current smoking, and Western diet by 25% in the general population might reduce the incidence of unprovoked VTE by 12%. We urge further research and consideration that primary prevention of unprovoked VTE may be a worthwhile public health aim.

Weight change over 9 years and subsequent risk of venous thromboembolism in the ARIC cohort

BACKGROUND/OBJECTIVES

Weight gain increases risk of cardiovascular disease, but has not been examined extensively in relationship to venous thromboembolism (VTE). The association between weight change over 9 years and subsequent VTE among participants in the Atherosclerosis Risk in Communities (ARIC) study was examined, with a hypothesis that excess weight gain is a risk factor for VTE, relative to no weight change.

SUBJECTS/METHODS

Quintiles of 9-year weight change were calculated (visit 4 1996-1998 weight minus visit 1 1987-1989 weight in kg: Quintile 1: ≥-1.81 kg; Quintile 2: <-1.81 to ≤1.36 kg; Quintile 3: >1.36 to ≤4.08 kg; Quintile 4: >4.08 to ≤7.71 kg; Quintile 5: >7.71 kg). Incident VTEs from visit 4 (1996-1998) through 2015 were identified and adjudicated using medical records. Hazard ratios (HRs) were calculated using Cox models.

RESULTS

529 incident VTEs were identified during an average of 19 years of follow up. Compared to Quintile 2, participants in Quintile 5 of weight change had 1.46 times the rate of incident VTE (HR = 1.46 (95% CI 1.09, 1.95), adjusted for age, race, sex, income, physical activity, smoking, and prevalent CVD). The HR for Quintile 5 was modestly attenuated to 1.38 (95% CI 1.03, 1.84) when visit 1 BMI was included in the model. When examined separately, results were significant for unprovoked VTE, but not for provoked VTE. Among those obese at visit 1, both weight gain (HR 1.86 95% CI 1.27, 2.71) and weight loss (HR 2.11 95% CI 1.39, 3.19) were associated with incident VTE, compared with normal-weight participants with no weight change.

CONCLUSIONS

Weight gain later life was associated with increased risk for unprovoked VTE. Among those with obesity, both weight gain and weight loss were associated with increased risk for VTE.

Pulmonary embolism in obesity-hypoventilation syndrome

INTRODUCTION

Obesity-hypoventilation syndrome occurs with alveolar hypoventilation during sleeping and daytime. Obesity may be a risk factor for venous thromboembolism. However, the venous thromboembolism in the obesity-hypoventilation syndrome is not well characterized.

OBJECTIVE

This case series aimed to investigate the presence and clinical features of venous thromboembolism in patients with the obesity-hypoventilation syndrome.

METHODS

Data of eight case reports were collected. Ages ranged from 36 to 73 years.

RESULTS

All patients had mosaic perfusion and enlarged main pulmonary artery, two had signs of infarction and mostly segmental and subsegmental filling defects. On the basis of this information some conclusions can be drawn carefully.

CONCLUSION

Present cases indicate that pulmonary embolism are also very common in patients with obesity-hypoventilation syndrome, anticoagulant therapy is at least as important as the treatment of the current disease. Clinicians will frequently be faced with patients with obesity-hypoventilation syndrome suspected of PE.

Changes in Childhood Body-Mass Index and Risk of Venous Thromboembolism in Adulthood

Background Childhood weight trajectories may influence cardiometabolic traits and thereby the risk of venous thromboembolism ( VTE ) later in life. We examined whether overweight and changes in weight status during childhood were associated with risk of VTE in adulthood. Methods and Results We used Danish medical registries to conduct a population-based cohort study of Danish schoolchildren aged 7 to 13 years and born during 1930-1989. We calculated body-mass index ( BMI ) z-scores based on weight and height measurements. We estimated hazard ratios using Cox regressions to examine associations between changes in BMI z-scores from 7 to 13 years of age and the subsequent risk of VTE . Among 313 998 children, 5007 girls and 5397 boys were diagnosed with VTE as adults. Compared with children with a normal BMI (25th to 75th percentile category) at both ages, children with a BMI persistently above the 75th percentile had a 1.30- to 1.50-fold increased risk of VTE in adulthood. Children who experienced a BMI increase from the 25th to 75th or >75th to 90th percentile to a higher percentile category had a 1.35- to 1.70-fold increased risk of adulthood VTE . Children whose BMI percentile category decreased between 7 and 13 years of age had a VTE risk similar to that of children with a persistently normal BMI . Conclusions Risk of VTE in adulthood was higher in children with a persistently above-average BMI . Whereas weight gain from 7 to 13 years of age additionally increased VTE risk, remission from overweight by 13 years of age completely reverted the risk.

Weight Change and Mortality from Cardiovascular Diseases: The Japan Collaborative Cohort Study

Aim: The aim of this study was to assess the association between weight change and mortality due to cardiovascular diseases (CVDs) in a Japanese population.

Methods: We used the data of a population-based prospective cohort study that was conducted from 1988 to 1990 in 45 areas throughout Japan. Among a total of 69,681 men and women aged 40–79 with no history of CVD or cancer at baseline, the association between weight change from 20 years of age to baseline and CVD-related mortality was evaluated.

Results: During a median follow-up period of 19.1 years, we observed 4,274 deaths from total CVD. After adjusting for age, sex, and other potential confounding factors, compared with participants with a weight change of < 2.5 kg (stable weight), participants with a greater weight change (either loss or gain) had an increased risk of mortality from total CVD (U-shaped association). The hazard ratios for the total CVD risk in participants with a weight loss and a weight gain of ≥ 12.5 kg were 1.50 (95% confidence interval [CI], 1.30–1.72) and 1.21 (95% CI, 1.07–1.36), respectively. The associations between weight change and risk of mortality from ischemic heart disease or stroke showed similar trends. The risk of intracerebral hemorrhage was associated with weight loss only. Weight change was not associated with mortality from subarachnoid hemorrhage.

Conclusions: Weight loss or gain could be a risk factor for mortality from total or ischemic CVD, while weight loss could be a risk factor for intracerebral hemorrhage.

Association of Preoperative Body Weight and Weight Loss With Risk of Death After Bariatric Surgery

IMPORTANCE

Perception of weight loss requirements before bariatric surgery varies among patients, physicians, and health insurance payers. Current clinical guidelines do not require preoperative weight loss because of a lack of scientific support regarding its benefits.

OBJECTIVE

To examine the association of preoperative body mass index (BMI) and weight loss with 30-day mortality after bariatric surgery.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from 480 075 patients who underwent bariatric surgery from 2015 to 2017 in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, which covers more than 90% of all bariatric surgery programs in the United States and Canada. Clinical and demographic data were collected at all participating institutions using a standardized protocol. Data analysis was performed from December 2018 to November 2019.

EXPOSURES

Preoperative BMI and weight loss.

MAIN OUTCOMES AND MEASURES

30-day mortality after bariatric surgery.

RESULTS

Of the 480 075 patients (mean [SD] age 45.1 [12.0] years; 383 265 [79.8%] women), 511 deaths (0.1%) occurred within 30 days of bariatric surgery. Compared with patients with a preoperative BMI of 35.0 to 39.9, the multivariable-adjusted odds ratios for 30-day mortality for patients with preoperative BMI of 40.0 to 44.9, 45.0 to 49.9, 50.0 to 54.9, and 55.0 and greater were 1.37 (95% CI, 1.02-1.83), 2.19 (95% CI, 1.64-2.92), 2.61 (95% CI, 1.90-3.58), and 5.03 (95% CI, 3.78-6.68), respectively (P for trend < .001). Moreover, compared with no preoperative weight loss, the multivariable-adjusted odds ratios for 30-day mortality for patients with weight loss of more than 0% to less than 5.0%, 5.0% to 9.9%, and 10.0% and greater were 0.76 (95% CI, 0.60-0.96), 0.69 (95% CI, 0.53-0.90), and 0.58 (95% CI, 0.41-0.82), respectively (P for trend = .003).

CONCLUSIONS AND RELEVANCE

In this study, even moderate weight loss (ie, >0% to <5%) before bariatric surgery was associated with a lower risk of 30-day mortality. These findings may help inform future updates of clinical guidelines regarding bariatric surgery.

Repeated assessments of physical activity and risk of incident venous thromboembolism

Essentials It is debated whether physical activity influences the risk of venous thromboembolism. The association was explored accounting for fluctuations in physical activity over time. Overall and in the elderly, physical activity was associated with 23% and 30% lower risk. A moderate proportion of the association (14-36%) was mediated via body mass index. SUMMARY: Background Whether physical activity influences the risk of incident venous thromboembolism (VTE) remains controversial, potentially because of methodological challenges, such as regression dilution bias. Objectives To investigate whether physical activity was associated with VTE risk, and explore the role of body mass index (BMI) as a mediator in a population-based cohort with repeated assessments of physical activity. Methods Participants (n = 30 002) attending one or more surveys of the Tromsø Study 4-6 (1994-1995, 2001-2002, and 2007-2008) were included and categorized on the basis of weekly physical activity. Incident VTE was registered until 31 December 2016. Hazard ratios (HRs) were calculated by the use of time-varying Cox regression models. The Aalen additive hazard model was used to quantify the total, direct and indirect effects of physical activity. Results There were 531 incident VTEs during follow-up. Physical activity (≥ 1 per week) was associated with a lower risk of VTE (HR 0.77, 95% confidence interval [CI] 0.64-0.92) than being inactive. The effect was most pronounced for those aged ≥ 65 years (HR 0.70, 95% CI 0.55-0.88) and for provoked events (HR 0.66, 95% CI 0.50-0.89). The differences in absolute risk between active and inactive individuals were - 0.42 (95% CI - 0.73 to - 0.14) and - 1.59 (95% CI - 2.74 to - 0.52) events annually per 1000 individuals in the total and elderly populations, respectively. A moderate proportion of the association (14-36%) was mediated via BMI. Conclusion Our findings suggest that regular physical activity is associated with a lower risk of VTE, particularly in the elderly. The association occurred at a low weekly amount of physical activity, and was only partly mediated by BMI.

Adiposity throughout the life course and risk of venous thromboembolism

OBJECTIVE

Adult body mass index (BMI) is strongly associated with venous thromboembolism (VTE), however whether earlier-life adiposity or other measures of adult adiposity are associated with VTE risk remains largely unknown.

MATERIALS AND METHODS

We evaluated associations of childhood somatotype, BMI in early adulthood, adult adiposity, and change in weight since early adulthood with incident VTE risk over ≥20 years of follow-up among 205,935 participants from Nurses' Health Studies (NHS/NHS II) and Health Professionals Follow-Up Study (HPFS), ages 29-76 at baseline. We estimated multivariable-adjusted hazard ratios for VTE using Cox proportional hazards models.

RESULTS AND CONCLUSIONS

Somatotype in childhood and young adulthood BMI were not significantly associated with VTE risk, after accounting for adult BMI. Adult BMI was strongly associated with VTE in all three cohorts (e.g., multivariable-adjusted HRs comparing ≥35 kg/m² vs. <22.5 kg/m²: NHS:3.03[95% CI: 2.58, 3.56], NHS II:3.82[95% CI: 3.24, 4.51], HPFS:2.81 [95% CI: 2.08, 3.80]; all p-trends < 0.01). Adult waist circumference was associated with greater VTE risk, even after adjusting for adult BMI (all p-trends < 0.01). Increasing weight gain from young adulthood was significantly associated with VTE after adjusting for current BMI among women (HR comparing gain ≥20 kg vs. no change: NHS:1.36[95% CI: 1.13, 1.65], NHS II:1.48[95% CI: 1.17, 1.87]) and not men (HPFS:1.20[95% CI: 0.97, 1.50]). These results indicate that BMI and adiposity are likely more important acutely than cumulatively over time in the etiology and prevention of VTE. Clinically, encouraging weight loss in individuals who are overweight or obese could help reduce VTE risk.

Managing Care of Critically Ill Bariatric Patients

Nearly 160 million Americans are overweight, obese, or morbidly obese. Morbid obesity and its numerous comorbidities are threats to a person's health. Moreover, hospitalized individuals living with adiposity-based chronic conditions are at risk for certain immobility hazards. Many individuals who are morbidly obese look to metabolic surgery as a means for achieving sustainable weight loss. This article addresses critical care needs of people living with excess weight or weight maldistribution, along with specific needs of those undergoing metabolic surgery.