Association of serum phosphorus with subclinical atherosclerosis in chronic kidney disease. Sex makes a difference.
BACKGROUND
Cardiovascular disease is the leading cause of mortality in chronic kidney disease (CKD). Serum phosphate has been associated to cardiovascular disease in the general population and this effect seems to be different according to sex. In the present study we analyze the effect of phosphate on subclinical atherosclerosis in the NEFRONA population and its effect depending on sex.


METHODS
Carotid ultrasound assessing the presence of plaques was performed by an itinerant team in 1687 CKD patients not in dialysis without previous cardiovascular events. Standard blood test and anthropometrical parameters were also recorded.


RESULTS
Multivariate linear regression to model phosphate levels in patients with CKD showed an interaction of sex with age. Thus, among men, serum phosphate levels declined significantly with age almost linearly. Serum phosphate levels in women under the age of 40-45 years overlapped with those in men and then stayed above, showing and overall constant relationship. Multivariate logistic regression analysis showed that higher phosphate levels associated with a higher risk of presenting atheromatous plaque. This risk however was different according to sex. In men, phosphate levels within the normal range associated with an increased risk of subclinical atheromatosis whereas in women this risk only increased with serum levels over the normal range.


CONCLUSIONS
This study demonstrates that phosphate levels are associated with the presence of subclinical atheromatosis in a large CKD population. This effect of phosphate on subclinical atheromatosis was different according to sex, suggesting that a recommended serum phosphate levels could be different for male than for female CKD patients.
Nephrology Service and Unit for the Detection and Treatment of Atherothrombotic Diseases (UDETMA), Hospital Universitari Arnau de Vilanova, IRBLLEIDA. Av. Rovira Roure 80, 25198 Lleida, Spain. Electronic address: mmartinconde@gmail.com.
Marisa
M
Martín
Biostatistics Unit, IRBLLEIDA. Av. Rovira Roure 80, 25198 Lleida, Spain.
Joan
J
Valls
Nephrology Service and Unit for the Detection and Treatment of Atherothrombotic Diseases (UDETMA), Hospital Universitari Arnau de Vilanova, IRBLLEIDA. Av. Rovira Roure 80, 25198 Lleida, Spain.
Angels
A
Betriu
Nephrology Service and Unit for the Detection and Treatment of Atherothrombotic Diseases (UDETMA), Hospital Universitari Arnau de Vilanova, IRBLLEIDA. Av. Rovira Roure 80, 25198 Lleida, Spain.
Elvira
E
Fernández
Experimental Nephrology Laboratory, IRBLLEIDA. Av. Rovira Roure 80, 25198 Lleida, Spain. Electronic address: Valdivielso@medicina.udl.es.
Jose M
JM
Valdivielso
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D015415:Biomarkers / Q000097:blood; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D002340:Carotid Artery Diseases / Q000097:blood* / Q000000981:diagnostic imaging / Q000453:epidemiology; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010758:Phosphorus / Q000097:blood*; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology; D014463:Ultrasonography; D055815:Young Adult
D015415:Biomarkers; D010758:Phosphorus
Atheromatosis; Chronic kidney disease; Phosphate; Sex differences