The relationship between serum pregnancy-associated plasma protein-A level in patients with aortic valve stenosis: a case-control study

OBJECTIVE

Calcific aortic stenosis (AS) is the most common form of calcific aortic valve disease. Many matrix metalloproteinase (MMP) have been shown to be expressed in aortic sclerosis and contribute to valve fibrosis and calcification. We investigated the relationship between Pregnancy-Associated Plasma Protein-A (PAPP-A) and AS.

METHODS

Sixty-one patients who referred to our cardiology clinic having AS diagnosed with transthoracic echocardiography and thirty control subjects were included in this study. The patient group was divided into two groups as mild and moderate-severe AS in terms of echocardiography results. Levels of C-reactive protein (CRP), insulin-like growth factor-1 (IGF-1) and PAPP-A were measured.

RESULTS

There was statistically significant difference between the patient and control group for PAPP-A (p = 0.009). In addition, the difference between MPV, IGF-1 and PAPP-A levels of control and AS groups was found. We found that serum PAPP-A level was an independent predictor of AS (B = 0.107, p = 0.01) by logistic regression analysis. In linear regression analysis, a significant correlation was found for AS severity with MPV, IGF-1 and PAPP-A levels, respectively (p = 0.025, p = 0.004, p = 0.035). It was revealed that PAPP-A and IGF-1 were negatively correlated (r = -0.327, p = 0.002). Correlation of serum PAPP-A level with echocardiographic parameters was no observed.

CONCLUSION

The level of PAPP-A may be a marker used in diagnosis rather than a marker used to determine the severity of AS. Studies with larger patient populations may further explain the role of PAPP-A in the diagnosis and treatment of AS.

Regular exercise training prevents aortic valve disease in low-density lipoprotein-receptor-deficient mice

BACKGROUND

Regular exercise training (ET) slows the progression of atherosclerotic lesions, reduces oxidative stress, and increases nitric oxide bioavailability, all of which may be expected to improve degenerative aortic valve disease.

METHODS AND RESULTS

Four-week-old low-density lipoprotein-receptor-deficient mice (n=94) were randomly divided into 4 groups: Group 1 (control group), normal diet plus sedentary activity; group 2 (cholesterol group), cholesterol diet plus sedentary activity; group 3 (regular ET group), cholesterol diet plus regular ET (60 min/day, 5 days/week) for 16 weeks; and group 4 (occasional exercise group), cholesterol diet plus occasional ET (1 day/week) for 16 weeks. At 20 weeks of age, histological analysis was performed. A significant increase in aortic valve thickness was evident in the cholesterol group compared with the control group. Importantly, regular but not occasional ET significantly reduced aortic valve thickness compared with the cholesterol group (control 31.3+/-3.0 mum, cholesterol 50.1+/-3.4 mum, regular exercise 30.4+/-1.2 mum, and occasional exercise 48.9+/-3.2 mum). Immunohistochemistry revealed that a cholesterol diet disrupted and regular ET preserved endothelial integrity on the aortic valve surface. Furthermore, serum myeloperoxidase, accumulation of macrophages and oxidized low-density lipoprotein, in situ superoxide, activated myofibroblasts/osteoblast phenotypes, and mineralization were increased in the cholesterol group but were decreased by regular ET. Polymerase chain reaction revealed increased messenger RNA expression for alpha-smooth muscle actin, bone morphogenetic protein-2, runt-related transcription factor-2, and alkaline phosphatase in the cholesterol group, whereas these were diminished by regular ET. Moreover, regular ET significantly increased circulating levels of fetuin-A compared with the cholesterol group.

CONCLUSIONS

In the low-density lipoprotein-receptor-deficient mouse, regular ET prevents aortic valve sclerosis by numerous mechanisms, including preservation of endothelial integrity, reduction in inflammation and oxidative stress, and inhibition of the osteogenic pathway.