No abstract

A low-sodium diet is an essential part of the treatment of hypertension. However, some concerns have been raised with regard to the possible reduction of iodine intake during salt restriction. We obtained 24-h urine collections for the evaluation of iodine (UIE) and sodium excretion (UNaV) from 136 hypertensive patients, before and after 9 ± 1 weeks of a simple low-sodium diet. Body mass index (BMI), blood pressure (BP), and drug consumption (DDD) were recorded. Data are average ± SEM. Age was 63.6 ± 1.09 year. BMI was 25.86 ± 0.40 kg/m2 before the diet and 25.38 ± 0.37 kg/m2 after the diet (p < 0.05). UNaV decreased from 150.3 ± 4.01 mEq/24-h to 122.8 ± 3.92 mEq/24-h (p < 0.001); UIE decreased from 186.1 ± 7.95 µg/24-h to 175.0 ± 7.74 µg/24-h (p = NS); both systolic and diastolic BP values decreased (by 6.15 ± 1.32 mmHg and by 3.75 ± 0.84 mmHg, respectively, p < 0.001); DDD decreased (ΔDDD 0.29 ± 0.06, p < 0.05). UNaV and UIE were related both before (r = 0.246, p = 0.0040) and after the diet (r = 0.238, p = 0.0050). UNaV and UIE were significantly associated both before and after the diet (p < 0.0001 for both). After salt restriction UIE showed a non-significant decrease remaining in an adequate range. Our dietary suggestions were aimed at avoiding preserved foods, whereas the cautious use of table salt was permitted, an approach which seems safe in terms of iodine intake.

The official guidelines for hypertension recommend a low sodium diet as a basic approach. Sodium should be restricted to 100 mEq a day. Such tight diets are seldom paralleled by an adequate compliance. Methods: we studied the effects of a reasonable and realistic low sodium diet on the BP values in 196 pts. (157 pts. completed the study). The patients had to avoid ice creams, cheese and salt-preserved (cured) meat. They were switched from regular to salt-free bread. Otherwise they were free to follow their usual mediterranean diet. Urinary output of Na and K, weight, number of antihypertensive drugs taken, and office BP/HR were measured before diet started (Value 1 in the table) and after 9±1 weeks on diet (Value 2 in the table) (all values are mean ± SD). The BP was recorded with the patient alone, in a seated position, with automatic repeated measures, by means of Omron 907 HEM monitors. At the end of the study 88 patients showed a reduction in the urinary sodium (compliant pts.), whereas 69 did not (noncompliant pts.). In those compliant to the low salt approach (88 out of 157 pts. i.e. 56%), a substantial improvement was attained in terms of BP control and body weight with a simultaneous significant reduction in the daily drug requirement. The responders increased from 47 to 69 (i.e. from 53% to 78%). In the noncompliant group the BP values, the responder rate (35 to 32, i.e. 50% to 46%), the weight, and the drug consumption were stable. Conclusion: even a limited dietary salt reduction may be beneficial in terms of BP control, with a decrease of the BP levels and an increase in the responder rate, paralleled by a reduction of the drug requirement. Take home message: even a bit of diet is better than no diet.