Biomarkers for abdominal aortic aneurysms from a sex perspective.
BACKGROUND
Abdominal aortic aneurysms (AAAs) differ in men and women. Women are older at diagnosis, have a higher risk of rupture, and worse outcome after surgery compared with men. The higher occurrence of AAAs in men accounts for the dominance of men in biomarker analyses.


OBJECTIVE
The primary aim of this study was to investigate levels of established biomarkers for AAA in men and women, and the secondary aim was to compare biomarker levels in women with and without AAAs.


METHODS
In this prospective case-control study, blood samples were collected from 16 women and 18 men with AAAs ≥5.5 cm, from 20 women with AAAs <5.5 cm, and from 18 women with peripheral artery disease (PAD). Plasma concentrations of matrix metalloproteinase (MMP) -2, -9, and -13; tissue inhibitor of MMP-1 (TIMP-1); plasminogen activator inhibitor 1 (PAI-1); high-sensitivity C-reactive protein (hsCRP); and estradiol levels were analyzed by ELISA. An ultrasound examination was performed in women with PAD to exclude an AAA.


RESULTS
Age and other comorbid conditions were similar between men and women with AAAs. Women with AAAs had higher levels of MMP-9 compared with men with equally large AAAs (42.8 ng/mL vs 36.2 ng/mL, P = 0.036) and lower levels of estradiol (30.0 pmoL vs 86.5 pmol/L, P < 0.001). Women with AAAs had lower levels of MMP-9 compared with women without (59.5 ng/mL vs 132.6 ng/mL, P = 0.010). There was no significant difference in the plasma levels of MMP-2, MMP-13, hsCRP, PAI-1, TIMP-1, and estradiol between women with and without AAAs.


CONCLUSIONS
The higher levels of MMP-9 in women compared with men with equally large AAAs could suggest that MMP-9 is a biomarker related to the sex differences in aneurysm development. The lower levels of estradiol in women with AAAs compared with men suggest that the possible protective effect of endogenous estrogen cannot be explained by a difference in circulating levels of estradiol.
Department of Vascular Surgery, Karolinska University Hospital, Stockholm, Sweden. christina.villard@karolinska.se
Christina
C
Villard
Dick
D
Wågsäter
Jesper
J
Swedenborg
Per
P
Eriksson
Rebecka
R
Hultgren
D000328:Adult; D000367:Age Factors; D017544:Aortic Aneurysm, Abdominal / Q000097:blood* / Q000201:enzymology*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000097:blood; D020778:Matrix Metalloproteinase 2 / Q000097:blood; D020780:Matrix Metalloproteinase 9 / Q000097:blood; D053505:Matrix Metalloproteinases, Secreted / Q000097:blood*; D008875:Middle Aged; D010960:Plasminogen Activators / Q000097:blood*; D011446:Prospective Studies; D012727:Sex Characteristics; D012737:Sex Factors; D010959:Tissue Plasminogen Activator / Q000097:blood
D015415:Biomarkers; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; D053509:Matrix Metalloproteinase 13; D053505:Matrix Metalloproteinases, Secreted; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9