SERUM ZINC AND PLASMA-LIPOPROTEINS IN ELDERLY WOMEN - FINDINGS FROM THE NUN STUDY

Supplementation with zinc has been associated with changes in lipoprot ein levels in prior studies. The purpose of this study was to define f urther the relationship between serum zinc and plasma total cholestero l, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, and triglycerides. This study was conducted in a h omogeneous population of elderly women who were not taking zinc supple ments. Fasting blood samples were drawn from 87 women, 77-99 years old . Serum zinc concentrations were significantly positively correlated w ith total cholesterol (r = 0.37, P = < 0.01) and with LDL-cholesterol (r = 0.41, P = < 0.001). In 77-84-year-old women (N = 47), a normal se rum zinc level (70-150 mu g/dl) was associated with a 27 mg/dl higher mean LDL-cholesterol (P = 0.06) compared to low serum zinc (<70 mu g/d l). In 85-99-year-old women (N = 40), a normal serum zinc was associat ed with a 49 mg/dl higher mean LDL-cholesterol (P = 0.002) compared to low serum zinc. These associations were not materially affected by th e potential confounding effects of weight weight change over 8 years, triceps skinfold, or serum C-reactive protein. Overall, serum zinc con centration had a strong positive association with plasma LDL-cholester ol and to a lesser extent, with total plasma cholesterol in this popul ation. The association between serum zinc and plasma cholesterol may b e due to a third factor, such as red meat consumption, which is a sign ificant source of zinc and saturated fat. Alternatively, zinc may play a role in cholesterol metabolism. (C) 1996 Wiley-Liss, Inc.