Introduction: The importance of insulin clearance (CLins) on insulin dynamics and the role exerted in controlling glucose in type 2 subjects has recently been appreciated. Moreover, evidence in mice showed that CLins is reduced by incretin hormones at physiological levels.

Aim: To evaluate in 29 young (19±1 years) multi-ethnic Asian type 2 subjects (T2D) the contribution of CLins to insulin dynamics and if an association exists with GLP-1.

Methods: T2D (15F/14M; BMI=30.2±0.9 kg/m2; HbA1c=8.8±0.4% [73±4.4 mmol/mol]; mean duration of disease 2.5 years) had fasting glucose Gb=192±14 mg/mL and insulin Ib=19±3 µU/mL. They were compared to 17 (8F/9M) age-matched nondiabetic overweight (BMI=27.8±1.0, p=0.1) control subjects (CT, Gb=82±1, p<0.0001; Ib=12±2, p=0.09). All underwent a 75g 2h OGTT with measurements of glucose, insulin, C-peptide and GLP-1. Insulin secretion (ISR) was assessed by deconvolution from peripheral C-peptide; CLins) by ISR/AUCinsulin; beta cell function (BCF) by AUCC-peptide/AUCglucose; insulin sensitivity by OGIS model. GLP-1 effect on BCF (GLPE) was empirically calculated as BCF/AUCGLP-1.

Results: T2D were insulin resistant (OGIS=277±16 mL/min m2 vs. 424±14) and had low BCF (82±11 pmolC-peptide/mmolglucose vs. 123±10), both p<0.0001. Lower total AUCinsulin was observed in T2D (4.7±0.7 U/L 2h vs. 11.0±1.4, p<0.0001), with higher CLins (2.06±0.19 L/min) than in CT (1.46±0.10, p=0.023). CLins directly correlated with OGIS in CT (R=0.55, p=0.02), but not in T2D (p=0.98). Despite no difference was observed in AUCGLP-1 (1.6±0.1 nmol/L 2h vs. 1.7±0.1 in CT, p=0.63), which did not correlate with CLins (p>0.2), GLPE was lower in T2D (6.2±0.9 vs. 23.4±2.3, p<0.0001).

Conclusion: Reduced peripheral insulin availability in obese young Asian T2D is due not only to a markedly impaired beta cell function and reduced GLP-1 effect, but also to an increased insulin clearance, which however shows no association to GLP-1 response.

Disclosure

G. Pacini: None. A. Tura: None. C. Hor: None. S. Lim: None. F. Tan: None. C. Tong: None. J.Y.H. Hong: None. F. Md Zain: None. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. Board Member; Self; Zealand Pharma A/S. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., AstraZeneca. Research Support; Self; Danish Diabetes Academy, Novo Nordisk Foundation. Other Relationship; Self; Antag Therapeutics. Other Relationship; Spouse/Partner; Antag Therapeutics. W. Mohamud: None. T. Yeow: None.

© 2018 by the American Diabetes Association.
2018
Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at http://www.diabetesjournals.org/content/license.