ORLANDO, Fla.—Higher serum phosphorus is associated with lower pulse pressure in women, but not men with nondialysis-dependent CKD, according to researchers.
Elevated serum phosphorus has been linked to vascular calcification, cardiovascular events, and higher all-cause mortality among individials with and without CKD, the investigators explained. Furthermore, the association may be stronger in men than in women. Pulse pressure—defined as mean systolic pressure minus mean diastolic pressure—is a reflection of vascular stiffness and therefore may be related to vascular calcification associated with hyperphosphatemia. Previously, it was unknown whether phosphorus was associated with pulse pressure in nondialysis-dependent CKD.
Researchers led by Georges Saab, MD, of Washington University School of Medicine in Saint Louis, studied 6335 participants in the Kidney Early Evaluation Program (KEEP) who had CKD (defined as an estimated glomerular filtration rate below 60 mL/min/1.73 m2). After adjusting for age, race, body mass index, smoking, and other potential confounders, women in the highest phosphorus quartile (greater than 4.2 mg/dL) had a pulse pressure approximately 1.5 mm Hg lower than those in the lowest quartile (3.4 mg/dL or less). There was no difference in pulse pressure across phosphorus quartiles in men.
“The mechanisms behind the gender differences and whether such a small reduction in pulse pressure leads to these differences is unknown and warrants further study,” Dr. Saab said.
The investigators presented their study findings here at the National Kidney Foundation’s 2010 Spring Clinical Meetings.