Coffee, nutritional status, and renal artery resistive index

The relationship between nutrition and atherosclerosis is known, even dissociated from protein malnutrition. Cardiovascular impact of several nutrients is known; among them the action of coffee is still debated and cardiovascular effect of caffeine has been investigated without definite results.

The aim of this study is to investigate whether coffee habits, and/or quantity of coffee consumption, have any relationship with renal resistive index (RRI), a hallmark of arterial stiffness (AS). The relationship of AS with nutritional status assessed by body composition and serum albumin, insulin resistance (assessed by HOMA), and renal function assessed by glomerular filtration rate (GFR) is concurrently investigated.

This study was done with 221 consecutive patients, without diabetes, cancer, liver, renal, and heart disease, referred for clinical noninvasive assessment and nutritional counseling: 124 essential hypertensive and 97 nonhypertensive patients were eligible. Personalized Mediterranean diet, physical activity increase, and smoking withdrawal counseling were provided.

By multiple linear regression, fat-free mass (FFM), HOMA (positive relationship), and number of cups of coffee/day (negative relationship) account for 17.2% of the variance to RRI. By odds ratios lower risk to increased RRI is associated with higher serum albumin, higher hemoglobin, and FFM; greater risk is associated with hypertension, insulin resistance (HOMA ≥ 3.0), and renal insufficiency (GFR ≤ 90); coffee, assessed by number of cups/day, reduces risk.

Coffee use is inversely associated with RRI. Habitual coffee users have risk protection to higher RRI; lower serum albumin, insulin resistance, and renal insufficiency are associated with greater RRI.