Association of serum phosphorus with left ventricular mass in men and women with stable cardiovascular disease: data from the Heart and Soul Study.

Background: Higher serum phosphorus levels are associated with cardiovascular disease (CVD) events in the general population, an association that may be stronger in men. Estradiol has phosphaturic properties. Whether higher serum phosphorus levels are associated with left ventricular (LV) mass in persons without end-stage renal disease and whether the association is modified by sex is unknown.

Study Design: Cross-sectional observational study.

Setting & Participants: 978 outpatients with stable CVD.

Predictor: The primary predictor variable was serum phosphorus level. Sex was evaluated as an effect modifier.

Outcome & Measurements: LV mass using transthoracic echocardiography.

Results: The association of serum phosphorus level with LV mass differed by sex (interaction P=0.04). In models adjusted for age, race, kidney function, smoking, diabetes, blood pressure, cholesterol level, C-reactive protein level, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use, each 1-mg/dL higher serum phosphorus level was associated with 4.52-g/m2 greater LV mass (95% CI, 1.04-8.01; P=0.01) in men. Conversely, in women, no statistically significant association was found between serum phosphorus level and LV mass.

Limitations: Older adult population with stable CVD; 19% were women.

Conclusions: In outpatients with stable CVD, higher serum phosphorus levels are associated with greater LV mass in men, but not women. Whether sex hormones may account for these differences requires future study.