ZINC, BIOCHEMICAL MARKERS OF NUTRITION, AND TYPE-I OSTEOPOROSIS

Having observed previously that the reduction of levels of biological markers of nutrition in postmenopausal osteoporosis may be related to zinc deficiency, we measured plasma and urinary zinc concentrations in 30 women with postmenopausal osteoporosis and in 30 healthy postmenop ausal women who served as controls. Plasma zinc levels did not differ between groups, but urinary zinc excretion was significantly higher in the women with postmenopausal osteoporosis (p = 0.002). The relation between total body bone mineral content corrected for body weight (TBB MC/W) and markers of nutrition was significant (multiple regression an alysis: p < 0.0001) in the women with postmenopausal osteoporosis but not in the healthy postmenopausal controls. Likewise, the relation bet ween TBBMC/W and plasma and urinary zinc levels also was significant i n the women with postmenopausal osteoporosis but not in the controls ( multiple regression analysis: p = 0.0022). Neither group showed any co rrelation between plasma or urinary zinc concentrations and levels of biological markers of nutrition. Urinary zinc concentration correlated significantly with serum tartrate-resistant acid phosphatase level (s imple linear regression analysis: r = 0.583, p < 0.001) in the women w ith postmenopausal osteoporosis but not in controls. TBBMC correlated with urinary zinc concentration significantly in the women with postme nopausal osteoporosis (simple linear regression: r = 0.567, p = 0.0015 ), but the correlation was nonsignificant in healthy postmenopausal co ntrols. These findings indicate that the elevation of urinary zinc eli mination in osteoporosis is dependent on bone resorption.