The purpose of the study was to analyze data from the INTERMAP Study, an international, cooperative, 17-sample population study of 4,706 men and women ages 40-59 in four countries including the United States, the United Kingdom, China, and Japan. Analyses assessed the following: whether, independent of multiple possible confounding variables, there were significant relationships of dietary protein (total, animal, vegetable) and of dietary specific amino acids (AA) to 24-hour urinary excretion of total and individual AA and related compounds; systolic and diastolic blood pressure (BP) of individuals were related to their 24-hour urinary excretion of taurine -- a possible marker of fish protein intake; 1-methylhistidine, 3-methylhistidine, histidine, lysine, anserine (1-methylhistidine-B-alanine dipeptide) -- reflecting meat protein intake; arginine -- source in cells for nitric oxide (NO), implicated in vasodilation; other urinary amino acids.