Determinants of serum zinc concentrations in a population of French middle-age subjects (SU.VI.MAX cohort).

ABSTRACT

BACKGROUND/OBJECTIVES: Few studies have been conducted on determinants of serum zinc concentration, especially in France. The aim of this study was to investigate the relationships between serum zinc concentrations, and age, education, living area and life style in a large sample cohort of French adults. SUBJECTS/METHODS: Blood samples were collected after 12-h fasting in French adults (7448 women, 35-65 years old and 4926 men, 45-65 years old) participating to the SUpplementation in AntioXidant VItamins and Minerals cohort at enrolment. Serum zinc was determined by flame atomic absorption. RESULTS: Serum zinc concentration was lower in women (mean 12.9 µmol/l, 95% confidence interval 9.2-16.6 µmol/l) compared with men (mean 13.4 µmol/l, 95% confidence interval 9.7-17.1 µmol/l, P<0.0001). In total, 10% of the women showed serum zinc values <10.7 µmol/l and 10% of the men showed serum zinc values <11.3 µmol/l. Age was negatively associated with serum zinc only in men (P=0.001). In women, a positive association between smoking and serum zinc concentration (P=0.0003), and a negative relationship between highest education level and serum zinc concentration (P=0.01) were observed. With regard to geographical areas, the highest serum zinc concentrations were found in the Center, and the lowest in the Southwest of France for both men and women. The association between serum zinc concentrations and food categories or macronutrient intake disappeared after stratifying by gender. CONCLUSIONS: Age, gender and geographic area seem the main determinants of serum zinc concentrations in this study.