Improved Nocturnal Glycaemia and Reduced Insulin Use Following Clinical Exercise Trial Participation in Individuals With Type 1 Diabetes

Aim: To explore the influence of clinical exercise trial participation on glycaemia and insulin therapy use in adults with type 1 diabetes (T1D).

Research Design and Methods: This study involved a secondary analysis of data collected from 16 individuals with T1D who completed a randomized clinical trial consisting of 23-h in-patient phases with a 45-min evening bout of moderate intensity continuous exercise. Participants were switched from their usual basal-bolus therapy to ultra-long acting insulin degludec and rapid-acting insulin aspart as well as provided with unblinded interstitial flash-glucose monitoring systems. To assess the impact of clinical trial participation, weekly data obtained at the screening visit (pre-study involvement) were compared against those collated on the last experimental visit (post-study involvement). Interstitial glucose [iG] data were split into distinct glycaemic ranges and stratified into day (06:00–23:59) and night (00:00–05:59) time periods. A p-value of ≤ 0.05 was accepted for significance.

Results: Following study completion, there were significant decreases in both the mean nocturnal iG concentration (Δ-0.9 ± 4.5 mmol.L⁻¹, p < 0.001) and the time spent in severe hyperglycaemia (Δ-7.2 ± 9.8%, p = 0.028) during the night-time period. The total daily (Δ-7.3 ± 8.4 IU, p = 0.003) and basal only (Δ-2.3 ± 3.8 IU, p = 0.033) insulin dose requirements were reduced over the course of study involvement.

Conclusions: Participation in clinical research may foster improved nocturnal glycaemia and reduced insulin therapy use in people with T1D. Recognition of these outcomes may help encourage volunteers to partake in clinical research opportunities for improved diabetes-related health outcomes.

Clinical Trial Registration:DRKS.de; DRKS00013509.

Impact of survey length and compensation on validity, reliability, and sample characteristics for Ultrashort-, Short-, and Long-Research Participant Perception Surveys

INTRODUCTION

The validated Research Participant Perception Survey (RPPS-Long) elicits valuable data at modest response rates.

METHODS

To address this limitation, we developed shorter RPPS-Ultrashort and RPPS-Short versions, fielded them with the RPPS-Long to a random sample of a national research volunteer registry, and assessed response and completion rates, test/retest reliability, and demographics.

RESULTS

2228 eligible registry members received survey links. Response rates were 64% (RPPS-Ultrashort), 63% (RPPS-Short), and 51% (RPPS-Long), respectively (P<0.001). Completion rates were 63%, 54%, and 37%, respectively (p<0.001). All surveys were reliable with Cronbach's alpha = 0.81, 0.84, and 0.87, respectively. Retest reliability was highest for RPPS-Short (Kappa=0.85). Provision of compensation increased RPPS-Short completion rate from 54% to 71% (p<0.001). Compensated respondents were younger (p<0.001), with greater minority representation (p=0.03).

CONCLUSIONS

Shorter surveys were reliable and produced higher response and completion rates then long surveys. Compensation further increased completion rates and shifted sample age and race profiles.