A cross-sectional study of the correlation between diabetic therapy and serum zinc concentrations.

ABSTRACT

AIM: Zinc, an essential trace element, has various functions in humans. Zinc deficiency is associated with the elderly, patients with diabetes, and patients with frailty, a common geriatric syndrome. As few studies have reported the effects of anti-diabetic medication on zinc levels, we examined serum zinc concentrations in patients with diabetes and their correlation with anti-diabetic medications, especially in the elderly and patients with frailty, in Japan. METHODS: This cross-sectional study was conducted in 2014 and included 1033 patients with diabetes. Blood samples were taken, and a survey for the 8-item Short Form Health Survey of the Medical Outcomes Study was conducted. RESULTS: Because of renal dysfunction (with an estimated glomerular filtration rate of < 60 mL/min/1.73 m2), 337 patients out of 1033 were excluded. Hypozincemia was observed in 43.8% of the patients with diabetes. In 177 elderly patients with a low physical component summary score, multivariable logistic regression analysis revealed two anti-diabetic medications associated with hypozincemia GLP-1RA (multivariable-adjusted odds ratio [OR] 0.08, 95% confidence interval [CI] 0.010-0.657, p = 0.019) and metformin (OR 0.415, 95% CI 0.222-0.774, p = 0.006). In addition, metformin had a dose-dependent correlation with zinc levels (R = 0.3067, p < 0.0001). CONCLUSIONS: Oral administration of metformin in the elderly with diabetes and non-progressive renal dysfunction was not associated with hypozincemia, even at high doses. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13340-021-00521-6.