[Intracellular electrolytes and serum lipids in relation to dietary fatty acid intake]

In 12 moderately obese female probands without metabolic abnormalities, intracellular Mg++ activity, Na+ activity and Na+ concentration, and serum triglycerides, total cholesterol and HDL cholesterol were measured under a diet with fatty acids varying in the degree of saturation. During the diet with mainly saturated fatty acids the intracellular Na+ activity and concentration fell from 7.34 +/- 2.02 to 6.37 +/- 1.43 (p less than 0.05) and from 5.28 +/- 0.57 to 4.98 +/- 0.80 mmol/l respectively (mean values +/- SD). Intracellular Mg++ activity fell from 1.36 +/- 0.23 to 1.20 +/- 0.17 mmol/l (p less than 0.05). During the subsequent diet consisting of mainly polyunsaturated fatty acids, intracellular Na+ activity and concentration rose to 7.95 +/- 2.81 and 5.17 +/- 0.91 mmol/l respectively (p less than 0.05). The intracellular Mg++ activity showed a further decrease to 1.04 +/- 0.14 mmol/l (p less than 0.01). During the diet consisting of mainly saturated fatty acids there was a significant correlation between the changes in HDL cholesterol and intracellular Na+ activity (r = -0,78; p less than 0.01). The initial values of intracellular Mg++ correlated with HDL cholesterol (r = 0.53; p less than 0.05). Thus, moderate obesity at any rate was not associated with intracellular electrolyte disturbances. The composition of dietary fatty acids affects intracellular electrolyte composition. This may be caused on the one hand by modified membrane function due to the uptake of the various fatty acids into the membrane, and on the other hand by changes in the synthesis of prostaglandins depending on the intake of precursors.