Longer legs are associated with greater risk of incident venous thromboembolism independent of total body height. The Longitudinal Study of Thromboembolism Etiology (LITE)

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.

Diagnosis, Management of, and Return to Play Guidance for Venous Thromboembolism in Athletes

ABSTRACT

Venous thromboembolism (VTE) is not rare and is becoming more recognized in our athletic population. This diagnosis can be elusive. A provider must have a high clinical suspicion and use pretest probabilities to order the appropriate studies and accurately diagnose a VTE. Treatment using direct oral anticoagulants for 3 months is recommended in most cases. Gradual return to play can be achieved after treatment is complete. Some athletes, however, may require lifelong anticoagulation. Return to collision sports may be possible using a timed dose strategy if long-term anticoagulation is needed. The management of an athlete with a VTE should include an individualized treatment plan and involve shared decision making with the athlete, team physicians, and hematologic specialists.

In-Season Nutrition Strategies and Recovery Modalities to Enhance Recovery for Basketball Players: A Narrative Review

Basketball players face multiple challenges to in-season recovery. The purpose of this article is to review the literature on recovery modalities and nutritional strategies for basketball players and practical applications that can be incorporated throughout the season at various levels of competition. Sleep, protein, carbohydrate, and fluids should be the foundational components emphasized throughout the season for home and away games to promote recovery. Travel, whether by air or bus, poses nutritional and sleep challenges, therefore teams should be strategic about packing snacks and fluid options while on the road. Practitioners should also plan for meals at hotels and during air travel for their players. Basketball players should aim for a minimum of 8 h of sleep per night and be encouraged to get extra sleep during congested schedules since back-to back games, high workloads, and travel may negatively influence night-time sleep. Regular sleep monitoring, education, and feedback may aid in optimizing sleep in basketball players. In addition, incorporating consistent training times may be beneficial to reduce bed and wake time variability. Hydrotherapy, compression garments, and massage may also provide an effective recovery modality to incorporate post-competition. Future research, however, is warranted to understand the influence these modalities have on enhancing recovery in basketball players. Overall, a strategic well-rounded approach, encompassing both nutrition and recovery modality strategies, should be carefully considered and implemented with teams to support basketball players' recovery for training and competition throughout the season.

Association between greater leg length and increased incidence of colorectal cancer: the atherosclerosis risk in communities (ARIC) study

PURPOSE

Previous studies have reported that taller people have an increased risk of colorectal cancer (CRC). We examined the association of two height components-leg length and sitting height-with CRC risk in 14,532 individuals aged 45-64 years in the Atherosclerosis Risk in Communities study.

METHODS

Anthropometrics were measured at baseline (1987-1989). Incident CRC cases (n = 382) were ascertained from 1987 to 2012. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard ratios for CRC and colon cancer across quintiles of sex-specific leg length and sitting height.

RESULTS

The highest (versus the lowest) quintile of leg length was associated with a 36% greater CRC risk (p-trend = 0.04), and 51% greater colon cancer risk (p-trend = 0.01). For the top four quintiles combined, risk was increased by 34% for CRC and by 45% for colon cancer versus the lowest quintile. Total height and sitting height were not significantly associated with CRC or colon cancer risk. A small number of cases (n = 57) limited our ability to conduct subgroup analyses for rectal cancer.

CONCLUSIONS

A positive association of leg length with CRC and colon cancer risk suggests that biological mechanisms leading to greater leg length during puberty may explain the association between taller height and CRC.

Body Height and Incident Risk of Venous Thromboembolism: A Cosibling Design

BACKGROUND

Body height has been associated with an increased risk of venous thromboembolism (VTE), but the association can be confounded with shared familial factors (genetic/environmental). A cosibling design is useful for deeper understanding about the relationship between VTE and height.

METHODS AND RESULTS

From Swedish national registry databases, we used a corelative design with full siblings alongside a general Swedish population sample. A cohort of male conscripts (n=1 610 870), born in 1951 to 1992 without previous VTE, was followed from enlistment (1969-2010) until 2012. Another cohort of first-time pregnant women (n=1 093 342) from the medical birth register, without previous VTE, was followed from first pregnancy (1982-2012) until 2012. Using the Multi-Generation Register, we identified all full-sibling pairs discordant for height. This cosibling design allowed for adjustment for familial factors (genetic/environmental). Compared with the tallest women (>185 cm) and men (>190 cm), there was a graded decreased risk by lower height for both men and women. The risk was lowest in women and men with the shortest stature (<155 and <160 cm, respectively): hazard ratios=0.31 (95% confidence interval, 0.22-0.42) and 0.35 (95% confidence interval, 0.22-0.55), respectively. There was a graded association also in the cosibling design comparing siblings with varying degree of discordance for height (reference was the taller sibling): ≥10 cm difference between brothers hazard ratios=0.69 (95% confidence interval, 0.61-0.78) and sisters hazard ratios=0.65 (95% confidence interval, 0.52-0.80), respectively.

CONCLUSIONS

Height is an independent predictor of VTE. The use of sibling pairs reduces the likelihood that familial confounding explains the results. The findings are important for the understanding of the pathogenesis of VTE.

Taller height as a risk factor for venous thromboembolism: a Mendelian randomization meta-analysis

Essentials Observational data suggest taller people have a higher risk of venous thromboembolism (VTE). We used Mendelian randomization techniques to further explore this association in three studies. Risk of VTE increased by 30-40% for each 10 cm increment in height. Height was more strongly associated with deep vein thrombosis than with pulmonary embolism.

SUMMARY

Background Taller height is associated with a greater risk of venous thromboembolism (VTE). Objectives To use instrumental variable (IV) techniques (Mendelian randomization) to further explore this relationship. Methods Participants of European ancestry were included from two cohort studies (Atherosclerosis Risk in Communities [ARIC] study and Cardiovascular Health Study [CHS]) and one case-control study (Mayo Clinic VTE Study [Mayo]). We created two weighted genetic risk scores (GRSs) for height; the full GRS included 668 single-nucleotide polymorphisms (SNPs) from a previously published meta-analysis, and the restricted GRS included a subset of 362 SNPs not associated with weight independently of height. Standard logistic regression and IV models were used to estimate odds ratios (ORs) for VTE per 10-cm increment in height. ORs were pooled across the three studies by the use of inverse variance-weighted random effects meta-analysis. Results Among 9143 ARIC and 3180 CHS participants free of VTE at baseline, there were 367 and 109 incident VTE events. There were 1143 VTE cases and 1292 controls included from Mayo. The pooled ORs from non-IV models and models using the full and restricted GRSs as IVs were 1.27 (95% confidence interval [CI] 1.11-1.46), 1.34 (95% CI 1.04-1.73) and 1.45 (95% CI 1.04-2.01) per 10-cm greater height, respectively. Conclusions Taller height is associated with an increased risk of VTE in adults of European ancestry. Possible explanations for this association, including taller people having a greater venous surface area, a higher number of venous valves, or greater hydrostatic pressure, need to be explored further.

Thrombosis Related ABO, F5, MTHFR, and FGG Gene Polymorphisms in Morbidly Obese Patients

Objective. Obesity is a well-known risk factor for thrombotic complications. The aim of the present study was to determine the frequency of thrombosis related ABO, F5, MTHFR, and FGG gene polymorphisms in morbidly obese patients and compare them with the group of nonobese individuals. Methods. Gene polymorphisms were analyzed in 320 morbidly obese patients (BMI > 40 kg/m²) and 303 control individuals (BMI < 30 kg/m²) of European descent. ABO C>T (rs505922), F5 C>G (rs6427196), MTHFR C>T (rs1801133), and FGG C>T (rs6536024) SNPs were genotyped by RT-PCR. Results. We observed a tendency for MTHFR rs1801133 TT genotype to be linked with morbid obesity when compared to CC genotype; however, the difference did not reach the significant P value (OR 1.84, 95% CI 0.83–4.05, P = 0.129). Overall, the genotypes and alleles of rs505922, rs6427196, rs1801133, and rs6536024 SNPs had similar distribution between morbidly obese and nonobese control individuals. Distribution of height and weight means among individuals carrying different rs505922, rs6427196, rs1801133, and rs6536024 genotypes did not differ significantly. Conclusions. Gene polymorphisms ABO C>T (rs505922), F5 C>G (rs6427196), MTHFR C>T (rs1801133), and FGG C>T (rs6536024) were not associated with height, weight, or morbid obesity among European subjects.

Guidance for the evaluation and treatment of hereditary and acquired thrombophilia

Thrombophilias are hereditary and/or acquired conditions that predispose patients to thrombosis. Testing for thrombophilia is commonly performed in patients with venous thrombosis and their relatives; however such testing usually does not provide information that impacts management and may result in harm. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance for thrombophilia testing in five clinical situations: following 1) provoked venous thromboembolism, 2) unprovoked venous thromboembolism; 3) in relatives of patients with thrombosis, 4) in female relatives of patients with thrombosis considering estrogen use; and 5) in female relatives of patients with thrombosis who are considering pregnancy. Additionally, guidance is provided regarding the timing of thrombophilia testing. The role of thrombophilia testing in arterial thrombosis and for evaluation of recurrent pregnancy loss is not addressed. Statements are based on existing guidelines and consensus expert opinion where guidelines are lacking. We recommend that thrombophilia testing not be performed in most situations. When performed, it should be used in a highly selective manner, and only in circumstances where the information obtained will influence a decision important to the patient, and outweigh the potential risks of testing. Testing should not be performed during acute thrombosis or during the initial (3-month) period of anticoagulation.

Body size measures, hemostatic and inflammatory markers and risk of venous thrombosis: The Longitudinal Investigation of Thromboembolism Etiology

OBJECTIVE

Obesity is an important venous thrombosis (VT) risk factor but the reasons for this are unclear.

MATERIALS AND METHODS

In a cohort of 20,914 individuals aged 45 and older without prior VT, we calculated the relative risk (RR) of VT over 12.6years follow-up according to baseline body size measures, and studied whether associations were mediated by biomarkers of hemostasis and inflammation that are related to adiposity.

RESULTS

Greater levels of all body size measures (weight, height, waist, hip circumference, calf circumference, body-mass index, waist-hip ratio, fat mass and fat-free mass) were associated with increased risk of VT, with 4th versus 1st quartile RRs of 1.5-3.0. There were no multiplicative interactions of biomarkers with obesity status. Adjustment for biomarkers associated with VT risk and body size (factors VII and VIII, von Willebrand factor, partial thromboplastin time, D-dimer, C-reactive protein and factor XI) only marginally lowered, or did not impact, the RRs associated with body size measures.

CONCLUSIONS

Greater body size, by multiple measures, is a risk factor for VT. Associations were not mediated by circulating levels of studied biomarkers suggesting that body size relates to VT because of physical factors associated with blood flow, not the hypercoagulability or inflammation associated with adiposity.

Orthostatic Hypotension and Risk of Venous Thromboembolism in 2 Cohort Studies

BACKGROUND

Although venous stasis is a risk factor for venous thromboembolism (VTE) and orthostatic hypotension (OH) can cause venous stasis, to our knowledge no study has examined the relationship between OH and VTE risk. We sought to quantify the association between OH and VTE (deep vein thrombosis or pulmonary embolism) using data from 2 large, prospective cohort studies: the Cardiovascular Health Study (CHS) and the Atherosclerosis Risk in Communities (ARIC) Study. We hypothesized that OH was positively associated with incident VTE.

METHODS

We measured OH-defined as a drop in systolic blood pressure (SBP) of at least 20 mm Hg or diastolic blood pressure (DBP) of at least 10 mm Hg within 3 minutes of standing-in participants aged 45-64 years in ARIC (n = 12,480) and ≥65 years in CHS (n = 5,027) at baseline visits (1987-1989 in ARIC; 1989-1990 and 1992-1993 in CHS), and followed participants for incident VTE (n = 568 in ARIC through 2011 and n = 148 in CHS through 2001). We calculated adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs) for incident VTE in relation to OH status.

RESULTS

In CHS, there was a positive association between OH status and incident VTE (HR for VTE = 1.74 (95% CI: 1.20-2.51)). In contrast, there was no association between OH and VTE in the ARIC study (HR for VTE = 0.97 (95% CI: 0.70-1.33)).

CONCLUSIONS

Community-dwelling older adults with OH had a moderately increased risk of VTE. These results were not seen in a population-based middle-aged cohort.

Sex difference in the risk of recurrent venous thrombosis: a detailed analysis in four European cohorts

BACKGROUND

Previous analyses reported a higher risk of recurrent venous thrombosis in men than women.

OBJECTIVES

We aimed to assess the risk of recurrence in men compared with women whilst taking female reproductive risk factors (oral contraception, postmenopausal hormone therapy and pregnancy) into account. In addition, we hypothesized that the sex difference in venous thrombosis was related to F9 Malmö, an X-linked prothrombotic factor.

METHODS

In four pooled European cohorts (CARROT study, Glasgow, UK; CVTE study, Cambridge, UK; AUREC study, Vienna, Austria; and LETS follow-up study, Leiden, the Netherlands), the risk of recurrent venous thrombosis was calculated in men, women with reproductive risk factors and women without reproductive risk factors at the time of their first venous thrombosis. F9 Malmö was genotyped and carriers and non-carriers contrasted.

RESULTS

In total, 2185 patients with a first venous thrombosis, 1043 men and 1142 women, were included. Overall, men had a 2.8-fold (95% confidence interval [CI], 2.2-3.4) higher risk of recurrent venous thrombosis than women. This risk was 5.2-fold (95% CI, 3.5-7.7) higher in men than in women with reproductive risk factors, and 2.3-fold (95% CI, 1.7-3.2) higher in men than in women without reproductive risk factors. No difference in risk of recurrence was found for carriers vs. non-carriers of F9 Malmö.

CONCLUSION

Men experienced a recurrent venous thrombosis twice as often as women without reproductive risk factors. These findings indicate that men have a higher intrinsic risk of venous thrombosis than women, which is partly masked by female reproductive risk factors. The sex difference cannot be explained by F9 Malmö.

Body height, mobility, and risk of first and recurrent venous thrombosis

BACKGROUND

Tall people have an increased risk of a first venous thrombosis. Sedentary lifestyle has been shown to act synergistically with body height, especially during long-haul flights.

OBJECTIVE

To estimate the relation between height and risk of a first and recurrent venous thrombosis and a possible additional association with a mobile or an immobile lifestyle.

METHODS

Patients with a first venous thrombosis and control subjects were included between 1999 and 2004 (MEGA case-control study). Patients were followed for recurrence for an average time of 5.1 years (MEGA follow-up study). Odds ratios and hazard ratios (HRs) per increase of 5 cm were calculated compared with a height of 165-170 cm, separately and in combination with (im)mobility.

RESULTS

In 4464 patients who reported their height, we found an increasing risk of a first and recurrent event with height. For men, a 2.9-fold (95% confidence interval [CI] 1.9-4.4) increased risk for first venous thrombosis was found for those between 195 and 200 cm and a 3.8-fold (95% CI 1.5-9.8) higher risk for those > 200 cm compared with the reference category. For recurrence risk, the HRs were 1.7 (95% CI 0.8-3.3) and 3.7 (95% CI 1.4-10.0), respectively. For women, a 1.5-fold (95% CI 0.7-3.4) and 3-fold (95% CI 0.9-9.4) increased risk was found for those > 185 cm for first and recurrent venous thrombosis, respectively. For the tallest men and women, a slight additionally increased risk was observed for sedentary lifestyle.

CONCLUSIONS

Tall men and women have an increased risk of first and recurrent venous thrombosis, possibly higher in combination with a sedentary lifestyle.

Differential risks in men and women for first and recurrent venous thrombosis: the role of genes and environment

Men have a higher risk of first and recurrent venous thrombosis than do women. However, the pathophysiology underlying this phenomenon is as yet unknown. In this review article, we assessed the prevalence and strength of genetic and acquired risk factors for venous thrombosis for men and women separately, because it is likely that either a difference in effect or distribution of a risk factor explains the risk difference between the sexes. We also summarized the sex-specific results of previous studies on the risk of first and recurrent venous thrombosis. Few explanations for the sex difference were found. The major factor, explaining about 20% difference in population-attributable fraction, was body height. No difference in prevalence or strength for other venous thrombosis risk factors was observed, such as plaster cast immobilization, hospitalization, surgery, trauma, malignancy, hyperhomocysteinemia, factor V Leiden, prothrombin G20210A, or blood group non-O. Alternative explanations for the sex difference are hypothesized in this review, including X- or Y-linked mutations or a mutation on a gene with a sex-specific effect. Future studies should focus on the sex-specific risk of venous thrombosis to unravel the pathophysiology and thereby improve sex-specific treatment and prevention strategies. Even so, male sex can be used as a tool through which individuals at increased risk of first or recurrent venous thrombosis may be identified.

Taller women are at greater risk of recurrent venous thromboembolism: the Iowa Women's Health Study

Venous thromboembolism (VTE) recurs frequently. Greater height is associated with increased risk of incident VTE, but it is unclear whether height is related to risk of VTE recurrence. Recurrent VTE is associated with substantial morbidity and mortality, thus identifying individuals at greatest risk of experiencing a recurrent event, who may benefit from extended anticoagulant therapy, is vitally important. Using data from the Iowa Women,s Health Study, we explored whether greater height was associated with increased risk of VTE recurrence.Among 1,691 women who experienced an initial VTE event, 286(16.9%) experienced a recurrent event. Risk of recurrence was 76%(95% CI: 16% -186%) higher among women >66 inches [168 cm] tall relative to those ≤62 inches [158 cm] tall, after adjustment for age and waist circumference. Future research should evaluate whether body height improves clinical prediction of VTE recurrence risk.