Interactive calculator to estimate insulin sensitivity in type 1 diabetes.

The gold standard for measuring insulin sensitivity (IS) is the hyperinsulinemic-euglycemic clamp, a time, costly, and labor-intensive research tool. A low insulin sensitivity is associated with a complication-risk in type 1 diabetes. Various formulae using clinical data have been developed and correlated with measured IS in type 1 diabetes. We consolidated multiple formulae into an online calculator (bit.ly/estimated-GDR), enabling comparison of IS and its probability of IS <4.45 mg/kg/min (low) or >6.50 mg/kg/min (high), as measured in a validation set of clamps in 104 adults with type 1 diabetes. Insulin sensitivity calculations using different formulae varied significantly, with correlations (R2) ranging 0.005-0.87 with agreement in detecting low and high glucose disposal rates in the range 49-93% and 89-100%, respectively. We demonstrate that although the calculated IS varies between formulae, their interpretation remains consistent. Our free online calculator offers a user-friendly tool for individual IS calculations and also offers efficient batch processing of data for research.

An online tool using clinical factors to estimate the probability of partial clinical remission of adult-onset Type 1 diabetes.

A type 1 diabetes (T1D) diagnosis is often followed by a period of reduced exogenous insulin requirement, with acceptable glucose control, called partial clinical remission (pCR). Various criteria exist to define pCR, which is associated with better clinical outcomes. We aimed to develop formulae and a related online calculator to predict the probability of pCR at 3- and 12-months post-T1D diagnosis. We analysed data from 133 adults at their T1D diagnosis (mean ± SD age: 27 ± 6 yrs., HbA1c 11.1 ± 2.0 %, 98 ± 22 mmol/mol), 3- and 12-months later. All patients were enrolled in the prospective observational InLipoDiab1 study (NCT02306005). We compared four definitions of pCR: 1) stimulated C-peptide >300 pmol/l; 2) insulin dose-adjusted HbA1c ≤9 %; 3) insulin dose <0.3 IU/kg/24 h; and HbA1c ≤6.4 % (46 mmol/mol); and 4) insulin dose <0.5 IU/kg/24 h and HbA1c <7 % (53 mmol/mol). Using readily available demographics and clinical chemistry data exhaustive search methodology was used to model pCR probability. There was low concordance between pCR definitions (kappa 0.10). The combination of age, HbA1c, diastolic blood pressure, triglycerides and smoking at T1D onset predicted pCR at 12-months with an area under the curve (AUC) = 0.87. HbA1c, triglycerides and insulin dose 3-mths post-diagnosis had an AUC = 0.89. A related calculator for pCR in adult-onset T1D is available at http://www.bit.ly/T1D-partial-remission.

Independent euglycaemic hyperinsulinaemic clamp studies validate clinically applicable formulae to estimate insulin sensitivity in people with type 1 diabetes.

BACKGROUND AND AIM: Low insulin sensitivity (IS) increases Type 1 diabetes (T1D) complication risk and can be estimated by simple formulae developed from complex euglycemic hyperinsulinaemic clamp studies. We aimed to validate these formulae using independent clamp data. METHODS: Clamps were performed in 104 T1D adults. Measured glucose disposal rate (GDR) was correlated with eGDR and eLog10 M/I calculated by five IS formulae. RESULTS: Correlations ranged between 0.23-0.40. Two IS formulae (by the authors), using age, sex, HDL-C, HbA1c, pulse pressure, BMI, and waist-hip-ratio had the highest correlation with measured GDR and the best performance in detecting low IS.