SYNERGISM OR COMPETITION BETWEEN ZINC AND CHROMIUM DIETARY LEVELS ON INSULIN ACTION MECHANISM. A METHOD TO INVESTIGATE

VINCENZO MONDA¹, ERSILIA NIGRO², MARIA RUBERTO³, GIUSEPPE MONDA¹, ANNA VALENZANO⁴, ANTONIO I. TRIGGIANI⁴, FIORENZO MOSCATELLI⁴, EMANUELE MONDA¹, INES VILLANO¹, MICHELE ROCCELLA⁵, LUCIA PARISI⁵, ANTONIETTA MESSINA^1,*

¹Department of Experimental Medicine, Università degli Studi della Campania-Luigi Vanvitelli, Italy - ²CEINGE-Biotecnologie Avanzate Scarl, Napoli, Italy - ³Department of Medical-Surgical and Dental Specialties; Università degli Studi della Campania-Luigi Vanvitelli, Italy, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy - ⁴Department of Psychological, Pedagogical and Educational Sciences, University of Palermo, Italy

Introduction: The action of zinc and chromium on the metabolism of carbohydrates and, consequently, on lipids and protein metabolism improves, on the one hand, the receptor membrane efficiency and, on the other hand, plays an important role in the regu- lation of secretion and insulin activity. Aim of the study is to gather preliminary data on the efficacy of treatment with zinc or chro- mium on impairment glucose tolerance.

Materials and methods: Subjects: All patients from a dietician examination had levels of blood sugar limits (35 men and 58 women; age 39-61 years). Diet food: intake of all nutrients was measured in weekly diary. The supplementation of chromium or zinc has been carried out - in a random way.

Statistical analysis: Data are expressed as mean ± SD or percentage changes from baseline.

Results: Blood glucose trigger levels of our patients (especially the elderly) was closely linked to the intake of chromium with diet rather than to zinc intake. The effect of dietary supplementation of chromium based on the contribution of some foods has a beneficial effect on the glucose tolerance test (0.5 g glucose / kg body weight) (Fig. 1-A) and on the basal blood glucose levels (Fig . 1-B). In particular, the basal level of glucose in the serum decreases after 1 month of treatment, and this is still true after 6 months.

Discussion: The effect of dietary chromium supplementation has a beneficial effect on the glucose tolerance test and fasting plasma glucose. The presence of zinc was less than chromium, but competes with the same chromium to the glucose tolerance test. The baseline serum glucose level decreases although it is still less than the amount detected in subjects treated with chromium.

We can speculate that zinc and chromium may present a competitive effect on the absorption of insulin secretion and insulin receptor.