Repeated assessments of physical activity and risk of incident venous thromboembolism

Cardiorespiratory fitness and future risk of venous thromboembolism

BACKGROUND

Cardiorespiratory fitness (CRF) is a strong predictor of future arterial cardiovascular disease and premature mortality. However, there are limited data on the association between CRF and the risk of incident venous thromboembolism (VTE).

OBJECTIVES

To investigate whether estimated CRF (eCRF) was associated with the risk of incident VTE in a cohort recruited from the general population.

METHODS

Participants (n = 10 393) from the sixth survey of the Tromsø Study (2007-08) were included, and incident VTEs were recorded up to 31 December 2016. CRF was estimated in sex-specific algorithms based on age, waist circumference, resting heart rate, and self-reported physical activity. Hazard ratios (HRs) with 95% confidence intervals (CIs) of VTE according to categories of eCRF were estimated in Cox regression models adjusted for sex with age as timescale. The impact of weight status was evaluated in analyses stratified by weight category.

RESULTS

There were 176 incident VTEs during follow-up. Compared with individuals with eCRF < 85% of age-predicted, those with eCRF of 85% to 100% and >100% of age-predicted had 46% (HR 0.54; 95% CI 0.39-0.77) and 67% (HR 0.33; 95% CI 0.20-0.54) lower VTE risk, respectively. Compared with overweight/obese individuals with eCRF < 85% of age-predicted, overweight/obese individuals with eCRF ≥ 85% had 50% (HR 0.50, 95% CI 0.35-0.74) lower risk, and normal weight individuals with eCRF ≥ 85% had 55% (HR 0.45, 95% CI 0.30-0.68) lower risk.

CONCLUSIONS

Higher eCRF was associated with lower risk of incident VTE. The association was independent of weight categories, suggesting that higher eCRF may modify the association between obesity and VTE.

Physical activity and risk of venous thromboembolism: systematic review and meta-analysis of prospective cohort studies

The inverse association between physical activity and arterial thrombotic disease is well established. Evidence on the association between physical activity and venous thromboembolism (VTE) is divergent. We conducted a systematic review and meta-analysis of published observational prospective cohort studies evaluating the associations of physical activity with VTE risk. MEDLINE, Embase, Web of Science, and manual search of relevant bibliographies were systematically searched until 26 February 2019. Extracted relative risks (RRs) with 95% confidence intervals (CIs) for the maximum versus minimal amount of physical activity groups were pooled using random effects meta-analysis. Twelve articles based on 14 unique prospective cohort studies comprising of 1,286,295 participants and 23,753 VTE events were eligible. The pooled fully-adjusted RR (95% CI) of VTE comparing the most physically active versus the least physically active groups was 0.87 (0.79–0.95). In pooled analysis of 10 studies (288,043 participants and 7069 VTE events) that reported risk estimates not adjusted for body mass index (BMI), the RR (95% CI) of VTE was 0.81 (0.70–0.93). The associations did not vary by geographical location, age, sex, BMI, and methodological quality of studies. There was no evidence of publication bias among contributing studies. Pooled observational prospective cohort studies support an association between regular physical activity and low incidence of VTE. The relationship does not appear to be mediated or confounded by BMI.

Physical activity and risk of recurrence and mortality after incident venous thromboembolism

BACKGROUND

Limited data exist on the relationship between physical activity and major complications after incident venous thromboembolism (VTE).

OBJECTIVES

To investigate whether physical activity was associated with risk of recurrence and mortality in patients with VTE recruited from the general population.

METHODS

Patients with incident VTE (n = 786) derived from the Tromsø Study surveys 4-6 (1994-1995, 2001-2002, and 2007-2008) were included, and data on physical activity were dichotomized according to the activity level reported in the survey preceding the incident VTE (inactive: <1 hour per week, active: ≥1 hour per week). Recurrent VTE and all-cause mortality were registered up to December 31, 2015. Hazard ratios (HRs) for recurrence and all-cause mortality were calculated using Cox regression models with the inactive group as reference.

RESULTS

There were 139 recurrences and 395 deaths during follow-up. Physical activity was not associated with the risk of recurrence in men (HR model 2: 1.48, 95% confidence interval [CI] 0.83-2.65) or in women (HR model 2: 0.95, 95% CI 0.52-1.74). In contrast, physical activity was associated with a 28% lower risk of mortality during 10 years of follow up (HR model 3: 0.72, 95% CI 0.57-0.91). The inverse association was stronger in patients with a first deep vein thrombosis ( HR model 2: 0.59, 95% CI 0.44-0.79) than a pulmonary embolism (HR model 3: 0.87, 95% CI 0.61-1.26).

CONCLUSION

Our results suggest that habitual physical activity prior to incident VTE does not influence the risk of recurrence. In contrast, active individuals were at lower risk of mortality, particularly following deep vein thrombosis.

Physical activity and risk of first-time venous thromboembolism

BACKGROUND

Physical activity may have a protective effect against venous thromboembolism (VTE). The aim of this study was to investigate the association between leisure time physical activity, occupational physical activity, and the risk of VTE in men and women separately.

METHODS

The population-based, prospective Venous thromboEmbolism In Northern Sweden (VEINS) cohort study included 108,025 participants of health examinations between 1985 and 2014. Physical activity data were collected by questionnaire. Participants were followed from health examination to first-time VTE event, death, emigration or the end of the study. All VTE events were validated by reviewing medical records and radiology reports.

RESULTS

During 1,496,669 person-years, 2054 participants experienced VTE. Women who performed leisure time physical activity at least once a week had a lower risk of first-time VTE (hazard ratio (HR) 0.83; 95% confidence interval (CI) 0.71-0.98 after adjustments) compared with women with less or no physical activity. Furthermore, women with high occupational physical activity also had a lower risk of VTE (HR 0.85; 95% CI 0.74-0.98). In men, there was no consistent association between either measure of physical activity and the risk of VTE.

CONCLUSION

We found an association between increased physical activity and a lower risk of first-time VTE in women.