Influence of dietary sodium restriction on lipid metabolism

The possible increase in total and low-density lipoprotein cholesterol following severe restriction of dietary NaCl was reported in 1990 and and 1991 from three experiments, one in the United States and two in Germany. Each of these experiments lasted only 1 week. To evaluate the clinical side effects we analyzed data collected from patients who completed a course of NaCl-restricted weight reduction at the Duke Diet and Fitness Center. Observations of lipid changes are not available for periods of less than 3 weeks; however, we were able to collect data on lipid and lipoprotein changes from 556 participants 25 days after they were referred for weight reduction. Total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels returned to normal in the majority of obese patients. In our slightly longer observation period in patients on a 1000 mg NaCl restricted diet we found no evidence of hyperlipidemic side effects. We believe that the hyperlipidemia resulting from severe sodium restriction in non-hypertensive, normal-weight individuals is not relevant to the problem of nonpharmacological and diuretic treatment of obese hypertensive patients. In clinically healthy, normal-weight, normotensive individuals severe salt restriction serves no practical or therapeutic purpose.