The effect of intensified diet counseling on the diet of hypertensive subjects in primary health care: a 2-year open randomized controlled trial of lifestyle intervention against hypertension in eastern Finland

BACKGROUND: Diet is an essential part of the nonpharmacological management of hypertension. The aim of this study was to investigate in a primary health care setting the effect of intensified diet counseling on the diet of hypertensive subjects. METHODS: A total of 715 free-living subjects, ages 25-74 years, with systolic blood pressure 140-179 mm Hg and/or diastolic blood pressure 90-109 mm Hg and/or drug treatment for hypertension participated in an open randomized trial with a 2-year follow-up at health centers in eastern Finland. The intervention group (n = 360) was advised to reduce their total fat, saturated fat, and salt intake and to increase monounsaturated and polyunsaturated fat intake as well as to reduce weight and to use alcohol in moderation if at all. The usual care group (n = 355) continued with their usual primary health care. The subjects filled out a 4-day food record, and 24-h urine samples were collected at baseline and at 1- and 2-year examinations. RESULTS: The 2-year net changes (change in intervention minus change occurring in usual care group) in total fat intake -2.7 E% (95% CI -4.0, -1.6; P < 0.0005)], in saturated fatty acid intake -1.7 E% (95% CI -2.3, -1.1; P < 0.0005)], and in body weight -1.4 kg (95% CI -2.0, -0.8; P < 0.0005)] were significant. Furthermore, the 2-year net change in daily sodium intake was significant, -9 mmol (95% CI -17, -2; P = 0.021), but the 24-h urinary sodium excretion showed no difference between the study groups. CONCLUSION: The intensified diet counseling in primary health care resulted in dietary changes interpreted as being of benefit in the long-term treatment of hypertension and prevention of atherosclerotic vascular diseases.