Serum concentrations of zinc and selenium in elderly people: results in healthy nonagenarians/centenarians

Trace elements such as zinc (Zn) and selenium (Se) play an important role i n maintaining the metabolic homeostasis in elderly people and the risk of d eficiency seems to increase in proportion to the age. Zn and Se concentrati ons, as indices of the micronutrient status in healthy subjects over 90 yea rs, are scarcely analyzed and could represent a model for studying the phys iology of successful aging. Our aim was to investigate Zn and Se concentrat ions in the healthy persons over the age of 90 years. One hundred and fifty two subjects volunteered for the study. They were divided into two groups: 90 non-institutionalized nonagenarians/centenarians (91-110 years) (group A) and 62 elderly subjects (60-90 years) used for comparison (group B). Ser um concentrations of Zn and Se were determined, respectively by flame atomi c absorption spectrophotometry (FAAS) and electrothermal atomic absorption spectrophotometry (ETAAS). The effect of age and sex on ion concentrations was investigated. Mean values + standard deviation of Zn and Se concentrati ons in the group A were 11.97 +/- 2.00 and 0.87 +/- 0.28 mu mol/l, respecti vely. A significant decrease of Se and Zn values was demonstrated in group A, when compared with group B, in both males and females. However, 84.4% of the 'healthy' nonagenarians/centerians had both Zn and Se concentrations e qual to or greater than the lowest values of the elderly group and only 3.3 % of cases showed both Zn and Se deficiencies. Consequently, a prospective and follow-up evaluation of Zn and Se could be proposed as a good index for a correct monitoring of the micronutrient deficiencies, that could represe nt an early sign of disease. (C) 2001 Elsevier Science Inc. All rights rese rved.