Kidney Function and Aortic Valve and Mitral Annular Calcification in the Multi-Ethnic Study of Atherosclerosis (MESA)

Ix, Joachim H.; Shlipak, Michael G.; Katz, Ronit; Budoff, Matthew J.; Shavelle, David M.; Probstfield, Jeffrey L.; Takasu, Junichiro; Detrano, Robert; O’Brien, Kevin D.

doi:10.1053/j.ajkd.2007.05.020

« Previous Next »American Journal of Kidney Diseases
Volume 50, Issue 3 , Pages 412-420, September 2007

Kidney Function and Aortic Valve and Mitral Annular Calcification in the Multi-Ethnic Study of Atherosclerosis (MESA)

Joachim H. Ix, MD, MAS
- Department of Medicine, University of California, San Francisco, CA
- Department of Nephrology, University of California, San Francisco, CA
- Address correspondence to Joachim H. Ix, MD, Division of Nephrology, Department of Medicine, Box 0532, HSE 672, University of California, San Francisco, San Francisco, CA 94143-0532.
Michael G. Shlipak, MD, MPH
- Department of Medicine, University of California, San Francisco, CA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA
- VA Medical Center, San Francisco, CA
Ronit Katz, PhD
- Department of Biostatistics, Collaborative Health Studies Coordinating Center, University of Washington, Seattle, WA
Matthew J. Budoff, MD
- Department of Medicine (Cardiology), Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
David M. Shavelle, MD
- Department of Medicine (Cardiology), Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
Jeffrey L. Probstfield, MD
- Department of Medicine (Cardiology), University of Washington, Seattle, WA.
Junichiro Takasu, MD
- Department of Medicine (Cardiology), Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
Robert Detrano, MD
- Department of Medicine (Cardiology), Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
Kevin D. O’Brien, MD
- Department of Medicine (Cardiology), University of Washington, Seattle, WA.

Received 29 January 2007; accepted 29 May 2007. published online 28 July 2007.

Background

Aortic valve calcification (AVC) and mitral annular calcification (MAC) are highly prevalent and predictive of mortality in end-stage renal disease populations. Whether less severe kidney dysfunction is associated with AVC and MAC is uncertain.

Study Design

Cross-sectional study.

Setting & Participants

Ethnically diverse middle-aged adults without clinically apparent cardiovascular disease who participated in the Multi-Ethnic Study of Atherosclerosis.

Predictor

Estimated glomerular filtration rate (eGFR), cystatin C, and microalbuminuria.

Outcomes & Measurements

AVC and MAC were determined by means of computed tomography. Multivariable logistic regression evaluated the association of kidney function with AVC and MAC.

Results

Of 6,785 participants, 10% had an eGFR less than 60 mL/min/1.73 m² (<1.0 mL/s/1.73 m²), mean cystatin C level was 0.9 ± 0.2 mg/L, 7% had microalbuminuria (albumin ≥ 30 mg/g), 15% had diabetes, 13% had AVC, and 9% had MAC. In adjusted analyses for AVC, eGFR less than 60 mL/min/1.73 m² (adjusted odds ratio, 1.23; 95% confidence interval, 0.99 to 1.14) and greater cystatin C concentrations (per SD increase; adjusted odds ratio, 1.06; 95% confidence interval, 0.99 to 1.14) had modest associations. Microalbuminuria was not associated independently with AVC (adjusted odds ratio, 1.11; 95% confidence interval, 0.89 to 1.40). For the MAC end point, associations of eGFR less than 60 mL/min/1.73 m² and greater cystatin C level differed by diabetes status (P for interaction = 0.1 and 0.02, respectively). In persons with diabetes, eGFR less than 60 mL/min/1.73 m² (adjusted odds ratio, 2.03; 95% confidence interval, 1.26 to 3.25) and greater cystatin C level (adjusted odds ratio, 1.38; 95% confidence interval, 1.14 to 1.68) were associated strongly, whereas no association was observed in subjects without diabetes (eGFR < 60 mL/min/1.73 m²: adjusted odds ratio, 1.13; 95% confidence interval, 0.86 to 1.49; cystatin C: adjusted odds ratio, 1.03; 95% confidence interval, 0.93 to 1.13). The association of microalbuminuria with MAC (adjusted odds ratio, 1.37; 95% confidence interval, 1.06 to 1.76) did not differ by diabetes status (P for interaction = 0.2).

Limitations

There were few participants with severe kidney disease.

Conclusions

Impaired kidney function had only a modest association with AVC, whereas its association with MAC was observed only in persons with diabetes. Future studies should evaluate whether associations of kidney impairment with dystrophic calcification differ by diabetes status in other clinical settings and vascular beds.

Index Words: Calcium, kidney disease, heart valve, computed tomography, cystatin C, albuminuria