Accelerated whole-body protein catabolism in subjects with type 2 Diabetes Mellitus and albuminuria

Abstract

Background Albuminuria develops in ~40% of subjects with Type 2 Diabetes Mellitus (T2DM), and is often associated with malnutrition, severe comorbidities and decreased life expectancy. The association between albuminuria and altered whole body protein turnover in T2DM is currently unknown. Objective To assess whole body protein degradation and synthesis in type 2 diabetes with and without albuminuria. Methods Fourteen T2DM male subjects, with either increased [AER+] or normal [AER-] urinary albumin excretion rate, and eleven age-matched male healthy controls, were infused with phenylalanine [Phe] and tyrosine [Tyr] tracers. Post-absorptive rates of appearance (Ra) of Phe (= protein degradation) and Tyr, Phe hydroxylation to Tyr (Hy) (catabolic pathway), and Phe disposal to protein synthesis [PS], were determined. Results Phe and Tyr Ra were not different among the groups. However, in T2DM [AER+], the fraction of Phe disposal to hydroxylation was ~50% and ~25% greater than that of both controls and T2DM [AER-] (p<0.006 and p = 0.17, respectively). Conversely, as compared to controls, the fractional Phe disposal to PS was ~10% lower in T2DM [AER+] (p<0.006), and not different from that in T2DM [AER-]. As a consequence, in T2DM [AER+], the ratio between the fractional Phe disposal to hydroxylation and that to PS was ~70% greater (p = 0.005) than that in healthy controls, whereas in the T2DM [AER-] this ratio was ~30% greater than in controls (p = 0.19). Conclusions On the basis of the kinetics of the essential amino acid phenylalanine, T2DM subjects with increased AER exhibit a catabolic pattern of whole body protein turnover.

How to Overcome Anabolic Resistance in Dialysis-Treated Patients?

“…However, this seems not to be the case for diabetic kidney disease. In a recent study Zanetti et al ( 84 ) observed that patients with diabetic kidney disease have a catabolic pattern of whole body protein turnover, associated with a 10% decrease in MPS ( 84 ). Therefore, multiple changes in protein metabolism, including an increase in protein degradation not associated with an adequately-matched change in protein synthesis account for accelerated wasting in patients with type 2 diabetic nephropathy.…”

Influence of Lemongrass Essential Oil (Cymbopogon flexuosus) Supplementation on Diabetes in Rat Model

“…All the groups of animals experienced body weight loss over the course of the experiment. This is associated with the chronic implications of type 1 diabetes, indicating lipid and protein catabolism, accompanied by polyuria and glucosuria [ 40 , 41 ]. Rats supplemented with EOCF at doses of 32 and 64 mg/kg and citral did not attenuate weight loss when compared to the control group (TW 80).…”

Evaluation of Antidiabetic and Antihyperlipidemic Activity of 80% Methanolic Extract of the Root of Solanum incanum Linnaeus (Solanaceae) in Mice

“…When STZ-induced diabetic mice were compared with normal mice, they lost a significant amount of body weight ( P < 0.01). The weight loss in diabetic mice might be linked to insulin insufficiency, which causes tissue protein breakdown and fat catabolism in adipose tissues [ 52 ]. However, the body weight of mice was significantly increased at 200 and 400 mg/kg of plant extract.…”