Objective: To find the prevalence of excessive salt intake among hypertensive patients in hypertension (HT) clinic at Siriraj Hospital. In addition, to correlate the epidemiologic characteristics of the studied group with high salt diet.
Material and Method: A cross-sectional study was conducted among 320 hypertensive patients in HT clinic at Siriraj Hospital from September 2010 to January 2011. Epidemiologic data, e.g., age, sex, body mass index, duration of treatment, education level, salary, frequency of salty food consumed/week and clinical data, e.g., renal function, (creatinine clearance, CCr) and anti-hypertensive drug(s) received were collected using pre-defined questionnaires. All volunteers were asked to collect 24-hour urine for 2 days to determine average daily amount of urine sodium (UNa). Those 24-hour UNa > 100 mmol/day were considered high salt intake. Correlations of high daily salt intake with all data collected were done.
Results: The prevalence of high salt intake was 73.4%. The mean total daily Na intake was 148 mmol/day i.e. 3.4 g of Na/day. When the influence of clinical characteristics on the risks of high salt intake was carried out, there were 2.42, 4.00 and 2.88 fold increases among those who have higher education level, those who have CCr > 60 ml/min/1.73 m2, and those who knew that salt could increase blood pressure (BP), respectively. About three-quarters (76.3%) of those patients who knew the effect of salt on BP consumed high salt diet.
Conclusion: The present study revealed that nearly three-quarters of hypertensive patients who attended the HT clinic still consumed high salt diet. Most patients who knew the effect of dietary salt on BP level ignored restriction about salt intake. In
addition, those patients with higher education and CCr > 60 ml/min/1.73 m2 also consumed high Na diet.

Keywords: High sodium intake, Hypertension