Associations of sodium, potassium and protein intake with blood pressure and hypertension in Switzerland.
Nutritional factors play an important role in the regulation of blood pressure and in the development of hypertension. In this analysis, we explored the associations of 24-hour urinary Na+, K+ and urea excretion with blood pressure levels and the risk of hypertension in the Swiss population, taking regional linguistic differences into account.



The Swiss Survey on Salt is a population based cross-sectional study that included 1336 subjects from the three main linguistic regions (French, German and Italian) of Switzerland. Blood pressure was measured with a validated oscillometric Omron HEM 907 device. Hypertension was defined as current antihypertensive treatment or a mean systolic blood pressure >140 mm Hg and/or diastolic >90 mm Hg, based on eight blood pressure measurements performed at two visits. Na+, K+ and urea excretion were assessed in 24-hour urine collections. We use multiple logistic/linear regressions to explore the associations of urine Na+, K+ and urea with blood pressure / hypertension, taking into account potential confounders and effect modifiers.



The prevalence of hypertension was 30%, 26% and 17% in the German-, French- and Italian- speaking regions respectively, (p-value across regions <0.001). In the Swiss adult population, besides age, sex, and body mass index, urinary Na+ excretion was positively associated with systolic blood pressure and hypertension. Urinary K+ excretion tended to be negatively associated with blood pressure but this was not significant (p = 0.08). Hypertensive people had a higher 24-hour urinary Na+/K+ ratio than normotensive people (p = 0.003). Urinary urea excretion was associated with neither blood pressure nor hypertension. Participants from the German-speaking region had a higher likelihood of having a high systolic blood pressure.



We confirm a high prevalence of elevated blood pressure in Swiss adults, including regional differences. In Switzerland, urinary Na+ excretion is associated positively with blood pressure and hypertension, independently of urinary K+ and urea excretion. The observed differences in blood pressure levels across linguistic regions are independent of the urinary Na+, K+ and urea excretion.
Service of Nephrology and Hypertension, Department of Medicine, Lausanne University Hospital, Switzerland.
Nicolas
N
Glatz
Community Prevention Unit, Institute of Social and Preventive Medicine, Lausanne University Hospital, Switzerland.
Aline
A
Chappuis
Department of Medicine, University Hospital, Basel, Switzerland.
David
D
Conen
Hypertension Centre, Luzerner Kantonsspital, Luzern, Switzerland.
Paul
P
Erne
Unit of Hypertension, Departments of Specialties of Medicine and Community Medicine and Primary Care and Emergency Medicine, Geneva University Hospitals, Switzerland.
Antoinette
A
Péchère-Bertschi
Unit of Population Epidemiology, Division of Primary Care Medicine, Department of Community Medicine, Primary Care and Emergency Medicine, Geneva University Hospitals, Switzerland.
Idris
I
Guessous
Service of Nephrology and Hypertension, Department of Medicine, Lausanne University Hospital, Switzerland.
Valentina
V
Forni
Division of Nephrology, Ospedale Carità, Locarno, Switzerland.
Luca
L
Gabutti
Praxis für Innere Medizin, Vezia, Switzerland.
Franco
F
Muggli
Cardiology Deptartment, Ospedale San Giovanni, Bellinzona, Switzerland.
Augusto
A
Gallino
Department of Internal Medicine and Angiology, Hôpital Cantonal de Fribourg, Switzerland.
Daniel
D
Hayoz
Nephrology/Transplantation Medicine, Kantonsspital, St Gallen, Switzerland.
Isabelle
I
Binet
Clinic and Policlinic of Internal Medicine, University Hospital of Zurich, Switzerland.
Paolo
P
Suter
Community Prevention Unit, Institute of Social and Preventive Medicine, Lausanne University Hospital, Switzerland.
Fred
F
Paccaud
Community Prevention Unit, Institute of Social and Preventive Medicine, Lausanne University Hospital, Switzerland.
Murielle
M
Bochud
Service of Nephrology and Hypertension, Department of Medicine, Lausanne University Hospital, Switzerland.
Michel
M
Burnier
D000293:Adolescent; D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure / Q000502:physiology*; D003430:Cross-Sectional Studies; D004044:Dietary Proteins / Q000652:urine; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000652:urine; D015995:Prevalence; D012982:Sodium, Dietary / Q000652:urine; D011795:Surveys and Questionnaires; D013557:Switzerland
D000959:Antihypertensive Agents; D004044:Dietary Proteins; D012982:Sodium, Dietary; D011188:Potassium