A Nutritional Questionnaire in an Adult Italian Hypertensive Population: Effects on Sodium and Potassium Intake (MINISAL-SIIA STUDY)

High salt consumption is an important determinant of high blood pressure (BP) and cardiovascular diseases. Several intervention studies showed that a reduction in salt consumption reduces BP and can reduce cardiovascular risk beyond the beneficial effect on BP in people with and without hypertension. The World Health Organization (WHO) recommends that adults should consume no more than 5 g of salt daily. However, the mean daily intake of salt in the majority of countries worldwide exceeds this recommendation. In contrast to salt, epidemiological and intervention studies suggest beneficial effects of dietary potassium on BP and cardiovascular risk. This effect seems more pronounced during high salt consumption. The WHO currently also recommends that adults should consume not less than 90 mmol of potassium daily. However, also for potassium the WHO recommendations are not generally met.

Several countries have made some progress towards reducing habitual salt intake through a voluntary or regulatory approach, achieving a reduction of BP and cardiovascular disease in the young population. Our previous observational data detected that Italian general population samples consumed high dietary salt and low dietary potassium, far from the WHO guidelines recommendation. Excess dietary salt intake in the hypertensive patients' population was observed in all age categories and there were no differences in salt intake among different regions. Likewise, in the same hypertensive population the adequate potassium intake in both men and women, in all age categories, and in all the regions surveyed was much below the recommendation. These results point out the potential target to improve BP and cardiovascular risk, in particular in hypertensive patients. An Italian survey of a large cohort of the general population showed that the degree of knowledge and behaviour about salt was directly interrelated. These data suggested that educational approach is crucial to improve the level of salt consumption. The reduction of salt intake has been recommended by WHO as a cost-effective action that should be undertaken. Hence, an intervention study targeted to reduce dietary salt intake and also to increase dietary potassium consumption by an educational intervention is needed.

Given these premises, the aim of the present intervention study will be to evaluate the effect of a brief educational intervention "MINIMAL-ADVICE" for improving dietary salt and potassium intake in a hypertensive population. In addition, the effect of the educational intervention on BP in relation to the potential variation of salt and potassium intake will be also evaluated.