Gregson J, et al. - In this analysis of individual-level data on several established cardiovascular risk factors from > 1.1 million participants in 76 cohorts, researchers evaluated the associations of major cardiovascular risk factors with venous thromboembolism (VTE), consisting of deep vein thrombosis or pulmonary embolism. According to findings, older age, smoking, and higher levels of adiposity were clearly linked to higher risk of VTE.

Methods

• This investigation included data from individual participants mainly from population-based cohort studies from the Emerging Risk Factors Collaboration (ERFC; 75 cohorts; n=731,728; years of baseline surveys, February 1960 to June 2008; latest date of follow-up, December 2015) and the UK Biobank (n=421,537; years of baseline surveys, March 2006 to September 2010; latest date of follow-up, February 2016).
• Participants without cardiovascular disease at baseline were also eligible for inclusion.
• From June 2017 to September 2018, data were analyzed.
• Exposures included a panel of several established cardiovascular risk factors.
• Main outcomes and measures included HRs per 1-SD higher usual risk factor levels (or presence/absence).
• The investigators analyzed incident fatal outcomes among those in the ERFC (VTE, n=1,041; coronary heart disease [CHD], n=25,131) and incident fatal/nonfatal outcomes among those in the UK Biobank (VTE, n=2,321; CHD, n=3,385).
• For age, sex, smoking status, diabetes, and BMI, HRs were adjusted.

Results

• Of the ERFC participants, 55.1% were female and the mean (SD) age at the time of the survey was 51.9 (9.0) years; of the participants from the UK Biobank, 55.4% were female and the mean (SD) age was 56.4 (8.1) years at the time of the survey.
• Older age (ERFC: HR per decade, 2.67; 95% CI, 2.45-2.91; UK Biobank: HR, 1.81; 95% CI, 1.71-1.92), current smoking (ERFC: HR, 1.38; 95% CI, 1.20-1.58; UK Biobank: HR, 1.23; 95% CI, 1.08-1.40), and BMI (ERFC: HR per 1-SD higher BMI, 1.43; 95% CI, 1.35-1.50; UK Biobank: HR, 1.37; 95% CI, 1.32-1.41) were included risk factors for VTE.
• Similar HRs for pulmonary embolism and deep vein thrombosis were found in the UK Biobank participants for these factors (except adiposity was more strongly associated with pulmonary embolism) and similar HRs for unprovoked vs provoked VTE.
• These risk factors, apart from adiposity, were less closely related to VTE than CHD.
• Inconsistent associations of VTEs with diabetes and blood pressure were note across ERFC and UK Biobank participants, and the ability to study lipid and inflammation markers was limited.