P2-9 Amino acids and incidence of hypertension in a Dutch older population: the Rotterdam Study

Abstract

Introduction: Epidemiological studies have shown an association between dietary protein and hypertension, which may be attributed to specific amino acids (AAs). Objectives: We examined the relation of dietary arginine, cysteine, lysine, proline and tyrosine with incident hypertension in 1958 men and women from the Rotterdam Study, aged ≥55 years, who were not treated with antihypertensive medication and were normotensive at baseline. Method/Design: Hazard ratios (95%CI) were calculated in tertiles of AA intake (expressed as percentage of total protein intake), using a Cox proportional model with adjustment for age, gender, BMI, smoking, alcohol intake, education, and intake of energy and several nutrients. Results: Mean systolic and diastolic blood pressure levels were 122±12 mmHg and 69±9 mmHg and dietary protein intake was 82±20 g/day (∼17 en%). Arginine (with nuts being the main source) contributed 5.3±0.4% of total protein intake, cysteine contributed 1.4±0.1% (main source: grain), lysine 6.8±0.4% (main source: meat), proline 7.4±0.6% (main source: dairy and grain), and tyrosine 3.7±0.1% (main source: dairy). Intake of these AAs was not significantly associated with incident hypertension (HRs ranging from 0.84 - 1.15; ptrend>0.15). We observed, however, a tendency towards an increased risk for lysine (HR upper tertile versus lower tertile 1.15; ptrend=0.21) and towards a decreased risk for tyrosine (HR 0.86; ptrend=0.15). Conclusions: We found no significant associations between AAs, and incidence of hypertension in this older population. There was, however, a tendency towards an adverse effect of lysine and a beneficial effect of tyrosine, which warrants further investigation in larger prospective studies.