Gender-specific Predicted Normal Aortic Size and Its Consequences of the Population-Based Prevalence of Abdominal Aortic Aneurysms.

BACKGROUND: To investigate if a relative-size-index of the abdominal aortic diameter influences the prevalence estimates of abdominal aortic dilatations compared to absolute diameters. METHODS: Cross-sectional study. Participants from the Viborg Vascular Screening Trial, Viborg Women Cohort, and the Viborg Screening Program. Through multivariate linear regression analyses, 2 gender-specific prediction-equations were developed based upon body-surface area and age. The definitions of absolute and relative size of aortic ectasies were 25-29 mm and 1.25-1.49× individual-predicted size (IPS), abdominal aortic aneurysm (AAA) 30 mm and 1.5× IPS, and large repair-recommendable AAA ≥55 mm or ≥ 2.75× IPS, respectively. RESULTS: Nineteen thousand two hundred and sixty nine males (69.6 years) and 2,426 females (67.1 years) attended the population- and ultrasound-based screening studies for AAA. The mean peak systolic abdominal anterior-posterior inner to inner diameter was 19.1 mm (±5.3 mm) and 16.6 mm (±2.8 mm) (P < 0.001) in males and females, respectively. Body surface area showed the strongest correlation with aortic diameters in both males (r = 0.19, P < 0.001) and females (r = 0.17, P < 0.001). Age correlated significantly with size, but only in males (r = 0.03, P < 0.001). The prevalence in men of absolute size-defined and relative size index-defined screening-detected aortic ectasies, AAAs and repair-recommendable AAAs were: 5.9% and 9.5% (P < 0.001), 3.3% and 4.2% (P < 0.001) and 9.9% and 15.2% (P = 0.004), respectively. Prevalence in females of absolute-size-defined and relative-size-index-defined screening-detected aortic ectasies, AAAs and repair-recommendable AAAs were 1.2% and 5.8% (P < 0.001), 0.5% and 1.3% (P = 0.003) and 0.0% and 23.1% (P = 0.553), respectively. CONCLUSIONS: Despite statistical differences, ultrasound-based absolute diameters to detect AAA seem acceptable in men. In females, poor agreements were noticed concerning all 3 categories of aneurysms, indicating that the current absolute diagnostic cut-points do not reflect female anatomy.

Vitamin K2 Dependent Matrix Gla Protein Relating to Abdominal Aortic Aneurysm and Overall Mortality: A Combined Case Control and Cohort Study.

OBJECTIVE: Inactivation of matrix Gla protein (MGP), using vitamin K antagonists or vitamin K deficiency results in increased vascular calcification, which has been associated with increased risk of symptomatic or ruptured abdominal aortic aneurysm (AAA). Insufficient activation of MGP leads to increased levels of undercarboxylated forms of MGP, measured as a dephosphorylated, undercarboxylated MGP (dp-ucMGP) in plasma. This study aimed to investigate whether the level of inactivated MGP influenced the risk of having an AAA, the risk of AAA progression, and overall mortality. METHODS: This combined case control and cohort study was based on data from the randomised, clinically controlled Viborg Vascular (VIVA) screening trial. Cases (n = 487) with an AAA and controls (n = 189) with neither peripheral artery disease nor AAA, had their plasma quantified for dp-ucMGP. Plasma levels were compared with the presence of an AAA, AAA growth rate, need for repair, and overall mortality. dp-ucMGP was divided into tertiles in regression analyses. RESULTS: The plasma levels of dp-ucMGP were higher for AAA cases compared with controls (median of 517 pmol/L vs. 495 pmol/L, p = .036). Adjusted analyses regarding dp-ucMGP being predictive of AAA, AAA growth rate, and need for repair all failed to show correlation. Overall mortality for AAA cases exhibited a significant association for the third tertile of dp-ucMGP with a hazard ratio of 2.55 (95% CI 1.29 - 5.05) compared with the first tertile. Overall mortality for controls was not correlated with dp-ucMGP plasma levels. CONCLUSION: dp-ucMGP did not correlate with the risk of having an AAA, AAA growth rate, or risk of surgery. For people with an AAA, dp-ucMGP was correlated with an increased mortality risk for the highest tertile of dp-ucMGP. This could suggest a role for prophylactic measures with vitamin K2 supplements to people at risk of AAA.