The Influence of Body Mass Index and Hypoglycaemic Drugs on the Circulating and Excreted Levels of Chromium Following an Oral Glucose Challenge, in Subjects with and without Diabetes Mellitus

Abstract

The possibility of an altered chromium metabolism in subjects with diabetes has been a topic of discussion for many years. The aims of this study were (a) measure the plasma chromium profile and excretion following a glucose challenge in controls, non-insulin dependent (NIDD) and insulin dependent diabetics (IDD), (b) observe the effect of obesity, (c) assess the effect of hypoglycaemic drugs on chromium. Subjects included 34 controls, 22 NIDD’s and 23 IDD’s. Groups subdivided by BMI; BMI 30 as obese. Food and drugs were withdrawn overnight and fasting urine was collected prior to the test. 75g glucose were given and blood collected every 30 mins. for 3 hrs. Urine was collected for 4 hrs. post glucose. Chromium was analysed by EAAS. Lean controls had significantly lower plasma chromium and insulin than oljese controls at all time points except zero (1hr; 0.66±0.35 vs 1.16±0.69ng.m1−1, p<0.020). No significant differences were seen between lean and obese NIDD’s and IDD’s. Lean controls pad lower chromium than lean NIDD’s (fasting; 0.68±0.30 vs 1.08±0.44ng.ml−1, p<0.01) but were not different from lean IDD’s No differences were seen in the chromium response of the obese groups. After subdivision of NIDD ‘s (i) medication, (ii) diet only; those taking dugs had higher chromium than lean controls (0.68±0.03 vs 1.16±0.26ng.ml−1, p<0.05), whereas lean NIDD’s diet only, were not different from lean controls. Mean chromium conc. of oral drugs was 22.4ng/tablet; the soluble insulins had 0.012±.003ng.U−1. No significant differences in chromium excretion either between or within groups. Results suggest chromium metabolism is influenced by BMI in controls; this was not seen in diabetics. Higher chromium was recorded in diabetics on hypoglycaemic drugs.