No detectable effect of a type 2 diabetes-associated TCF7L2 genotype on the incretin effect.

The T allele of TCF7L2 rs7903146 is a common genetic variant associated with type 2 diabetes (T2D), possibly by modulation of incretin action. In this study, we evaluated the effect of the TCF7L2 rs7903146 T allele on the incretin effect and other glucometabolic parameters in normal glucose tolerant individuals (NGT) and participants with T2D. The rs7903146 variant was genotyped in cohorts of 61 NGT individuals (23 were heterozygous (CT) or homozygous (TT) T allele carriers) and 43 participants with T2D (20 with CT/TT). Participants were previously examined by an oral glucose tolerance test (OGTT) and a subsequent isoglycemic intravenous glucose infusion (IIGI). The incretin effect was assessed by quantification of the difference in integrated beta cell secretory responses during the OGTT and IIGI. Glucose and hormonal levels were measured during experimental days, and from these, indices of beta cell function and insulin sensitivity were calculated. No genotype-specific differences in the incretin effect were observed in the NGT group (P = 0.70) or the T2D group (P = 0.68). NGT T allele carriers displayed diminished glucose-dependent insulinotropic polypeptide response during OGTT (P = 0.01) while T allele carriers with T2D were characterized by lower C-peptide AUC after OGTT (P = 0.04) and elevated glucose AUC after OGTT (P = 0.04). In conclusion, our findings do not exclude that this specific TCF7L2 variant increases the risk of developing T2D via diminished incretin effect, but genotype-related defects were not detectable in these cohorts.

Semaglutide improves health-related quality of life versus placebo when added to standard of care in patients with type 2 diabetes at high cardiovascular risk (SUSTAIN 6).

AIM: To assess what drives change in health-related quality of life (HRQoL) in type 2 diabetes in the SUSTAIN 6 trial and identify potential mediators of the treatment effect of semaglutide on HRQoL scores. MATERIALS AND METHODS: The Short Form (SF)-36v2® questionnaire [comprising physical component summary (PCS) and mental component summary (MCS)] was used to assess changes in HRQoL from baseline to week 104, by treatment, in a prespecified analysis. This post-hoc analysis assessed change in PCS and MCS using the following factors as parameter/covariate, using descriptive statistics and linear regressions: major adverse cardiac events, hypoglycaemia, gastrointestinal adverse events, at least one episode of nausea, vomiting or diarrhoea, and change in glycated haemoglobin (HbA1c), body weight, blood pressure, heart rate and estimated glomerular filtration rate. RESULTS: Mean change in overall PCS score was +1.0 with semaglutide versus +0.4 with placebo, and +0.5 versus -0.2 for MCS. The treatment effect of semaglutide versus placebo (unadjusted estimate) was 0.7 [(95% confidence interval 0.1, 1.2); P = 0.018] on PCS and this was reduced when adjusted for change in HbA1c [0.4 (-0.2, 1.0), P = .167] and body weight [0.3 (-0.3, 0.9), P = .314]. The unadjusted treatment effect on MCS [0.7 (-0.0, 1.5), P = .054] was only reduced when adjusted for change in HbA1c [0.3 (-0.4, 1.1), P = .397]. When adjusting for all other parameters separately, the estimated effect of semaglutide on PCS and MCS qualitatively did not change. CONCLUSIONS: Semaglutide improved HRQoL versus placebo; greater improvements with semaglutide versus placebo were possibly mediated, in part, by change in HbA1c and body weight. Clinicaltrials.gov: NCT01720446 (SUSTAIN 6).

The relationship between HbA1c and hypoglycaemia in patients with diabetes treated with insulin degludec versus insulin glargine 100 units/mL.

AIM: Treat-to-target, randomized controlled trials have confirmed lower rates of hypoglycaemia at equivalent glycaemic control with insulin degludec (degludec) versus insulin glargine 100 units/mL (glargine U100) in patients with type 1 (T1D) or type 2 diabetes (T2D). Treat-to-target trials are designed to enable comparisons of safety and tolerability at a similar HbA1c level. In this post hoc analysis of the SWITCH 1 and 2 trials, we utilised a patient-level modelling approach to compare how glycaemic control might differ between basal insulins at a similar rate of hypoglycaemia. MATERIALS AND METHODS: Data for HbA1c and symptomatic hypoglycaemia from the SWITCH 1 and SWITCH 2 trials were analyzed separately for patients with type 1 diabetes and type 2 diabetes, respectively. The association between the individual patient-level risk of hypoglycaemia and HbA1c was investigated using a Poisson regression model and used to estimate potential differences in glycaemic control with degludec versus glargine U100, at the same rate of hypoglycaemia. RESULTS: Improvements in glycaemic control increased the incidence of hypoglycaemia with both basal insulins across diabetes types. Our analysis suggests that patients could achieve a mean HbA1c reduction of 0.70 [0.05; 2.20]95% CI (for type 1 diabetes) or 0.96 [0.39; 1.99]95% CI (for type 2 diabetes) percentage points (8 [1; 24]95% CI or 10 [4; 22]95% CI mmol/mol, respectively) further with degludec than with glargine U100 before incurring an equivalent risk of hypoglycaemia. CONCLUSION: Our findings suggest that patients in clinical practice may be able to achieve lower glycaemia targets with degludec versus glargine U100, before incurring an equivalent risk of hypoglycaemia.