Protective Effect of Myo-Inositol Hexaphosphate (Phytate) on Abdominal Aortic Calcification in Patients With Chronic Kidney Disease.

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the relationship between physiological levels of myo-inositol hexaphosphate (phytate) and cardiovascular (CV) calcification in patients with chronic kidney disease (CKD). DESIGN AND METHODS: This was a prospective cross-sectional study conducted from December 2012 to June 2013. SUBJECTS: Sixty-nine consecutive patients with CKD who were not undergoing renal replacement therapy. INTERVENTION All subjects were given lateral lumbar X-rays to quantify abdominal aortic calcification (AAC). Clinical laboratory analyses and phytate food frequency questionnaires were also performed. MAIN OUTCOME MEASURE: Phytate urinary excretion, estimated phytate consumption (based on food frequency questionnaire) and AAC score. Patients were divided into two groups based on median abdominal aortic calcification (AAC) score no/mild AAC (AAC ≤ 6, n = 35) and moderate/severe AAC (AAC > 6, n = 34). RESULTS: Patients with no/mild AAC were younger, had lower pulse pressure, greater dietary intake of phytate, greater urinary phytate and the prevalence of prior CV disease was significantly lower compared to patients with moderate/severe AAC. Among the top 10 phytate-rich foods, lentil consumption was significantly greater in patients with no/mild AAC than in those with moderate/severe AAC. Multivariate logistic regression analysis indicated that age, prior CV disease, urinary phytate (or lentil consumption) were independently associated to AAC. CONCLUSION: Our results suggest that adequate consumption of phytate can prevent AAC in patients with CKD. Further prospective studies must be performed to elucidate the benefits of a phytate-rich diet and the associated risk of phosphorus bioavailability in these patients.