JMIR Publications

ABSTRACT

Background:

One in four Veterans who receive care within the Veterans Health Administration (VHA) has type 2 diabetes (T2D). Dietary carbohydrate restriction is one evidence-based strategy to support weight loss and blood glucose control among Veterans with T2D. Yet, little is known about how to tailor the degree of carbohydrate restriction to individual patients’ metabolic needs while mitigating risk of hypoglycemia among patients on certain anti-hyperglycemic medications (e.g., insulin). Continuous glucose monitoring (CGM) may support safe and effective use of carbohydrate restriction among Veterans with T2D.

Objective:

To develop and pilot test a low-carbohydrate (LC) nutrition counseling program guided by CGM for Veterans with T2D receiving insulin (i.e., LC-CGM).

Methods:

This is a pragmatic, non-randomized, pre-post quality improvement (QI) pilot to examine the feasibility and effectiveness of LC-CGM among Veterans with T2D using ≥ 3 daily injections of insulin at baseline. The 24-week intervention consists of virtual visits with a registered dietitian (RD) who provided individually tailored dietary advice and with a clinical pharmacy practitioner (CPP) who adjusted glucose-lowering medications with a focus on reducing or stopping insulin. The primary outcomes are program feasibility and acceptability including program uptake and engagement. Secondary outcomes are measures of clinical effectiveness including changes in weight, HbA1c, use of glucose-lowering medication, and achievement of clinically relevant weight change thresholds of ≥ 5% and ≥ 10%.

Results:

The program evaluation was conducted from March 19, 2021, to May 3, 2024. Among 43 Veterans referred to the LC-CGM program, 38 (88%) enrolled. Most were men (37/38, 97%), white (29/38, 76%), and the average age was 63.7 years. Mean BMI was 38.1 kg/m2 (SD 5.8). Mean HbA1c was 7.8% (SD 1.3). Of 38 enrollees, 27 (71%) completed the 24-week program. Enrollees averaged 9.5 RD visits and 12.9 CPP visits. In intention to treat analyses, mean weight change was -11.5 kilograms (SD 8.7), corresponding to 9.5% weight loss (SD 7.2), with 58% (22/38) achieving ≥ 5% weight loss and 32% (12/38) achieving ≥ 10% weight loss. Overall, use of glucose-lowering medications decreased from 3.5 per patient (SD 0.8) at baseline to 2.4 per patient (SD 0.9) at 24-weeks, with 72% (26/36) of Veterans discontinuing short-acting insulin and 50% (18/36) discontinuing of long-acting insulin. Use of Glucagon-like peptide-1 receptor agonists (GLP-1 RA) increased during the program period, with 39% (15/38) using at baseline and 61% (23/38) using at 24-weeks (p=0.02). Among program completers (n=27), mean percent weight loss was -11.8% (SD 6.5) and median HbA1c decreased by 0.7%, from 7.7% to 7.0%.

Conclusions:

A LC-CGM program is feasible, acceptable, and clinically effective among Veterans with T2D. Additional research is needed to rigorously test the program’s effectiveness among a larger cohort of eligible Veterans and evaluate longer-term outcomes.