The Association of Potassium Status with Parameters of Glucose Metabolism is influenced by Age in Adults.

Abstract

Potassium status has been found to affect glucose homeostasis. This study therefore aimed at investigating relationships between potassium status or dietary intake and fasting plasma glucose (FPG) or glycated haemoglobin (HbA1c) in a sample of Austrian adults (18-80 years, n = 421, 61% women) from the Austrian Study on Nutritional Status 2012. Dietary potassium intake was obtained by two 24 h recalls. FPG, plasma K+, and urinary K+ were determined photometrically, HbA1c by HPLC. Associations between the parameters were studied using multiple regression analysis after controlling for confounders and after age stratification of the sample (18-64 y vs. 65-80 y). Most of the participants had a potassium intake of less than the estimated adequate daily intake of 4000 mg/d. In the multiple regression analyses in the whole sample plasma K+ had a statistically significant positive effect on FPG only in the crude model (ß = 0.128, p < 0.01) and on HbA1c also in the fully adjusted model (ß = 0.129, p < 0.05). The small effects on HbA1c were also detected in the younger age group but were absent in the older population. However, in this latter, a reverse association of urinary K+ on HbA1c was observed as well as of dietary potassium intake on FPG with no effects in the younger sample. We suggest that age dependent differences in the association between parameters of potassium status and blood glucose regulation should also be taken into account.