Relationship between the nutritional status of zinc and cholesterol concentration of serum lipoproteins in adult male rats.

The effect of zinc status on the distribution of serum cholesterol among the major serum lipoproteins was assessed in adult male rats fed a zinc-deficient diet (0.37 ppm Zn) as compared with those of pair-fed and ad libitum-fed zinc-supplemented controls (41 ppm Zn). All data were collected within the first 4 wk of dietary treatment before the manifestation of any external symptoms of zinc deficiency. The acute zinc depletion produced a significant reduction in total serum cholesterol; the reduction was primarily due to the selective decline in high-density lipoprotein-cholesterol. Zinc depletion per se produced no significant alterations in very low-density lipoprotein- or low-density lipoprotein-cholesterol level. In addition, linear regression analysis based on the 36 pairs of serum zinc and high-density lipoprotein-cholesterol values showed a significant positive correlation (r = + 0.81; p less than 0.01) between these two parameters. The data also indicated a significant correlation between the ratio of zinc/copper and total serum cholesterol. This relationship was, however, solely dependent upon serum zinc status rather than serum copper. The serum levels of copper were not affected by zinc depletion over the period of 4 wk. These results present new evidence for the close association between the nutritional status of zinc and high-density lipoprotein concentration in adult male rats and draw attention to the potential significance of zinc nutriture in relation to cardiovascular health.