The effect of intensive lifestyle intervention (ILI) on A1C in real-world clinical practice is inconsistent and is frequently underestimated. It is also presumed that the magnitude of A1C improvement is solely dependent on the amount of weight loss. In this study we report the magnitude of A1C change in a large cohort of patients with diabetes who underwent ILI over 13 years in relation to their baseline A1C and the amount of weight loss.

We evaluated 590 diabetic patients (age 52.5±11 years, 58.6% females, A1C 7.7±1.4%, weight 105.54±18.6 Kg, BMI 36.7±5.1 Kg/m2, diabetes duration 10.9±9.8 years, 83.7% with type 2 diabetes), who enrolled in the Weight Achievement and Intensive Treatment (Why WAIT) program, a 12-week multidisciplinary ILI designed for real-world clinical practice between September 2005 and May 2018. We stratified patients based on baseline A1C into three groups: group A with A1C 9% (16.95% of participants), group B with A1C from 8 to <9% (19.15% of participants), and group C with A1C <8% (63.9% of participants). After 12 weeks of intervention, body weight decreased by 8.5±4.6 Kg in group A, 8.0±4.6 Kg in group B, and 7.6±5.8 Kg in group C (p=0.22 between groups). A1C decreased by 2.5±1.3% in group A, 1.2±0.8% in group B and 0.5±0.6% in group C (p<0.001 between groups). Pairwise comparisons of A1C changes between groups showed that: group A had 1.3% greater A1C reduction than group B (p=0.0001) and 2% greater A1C reduction than group C (p=0.0001), while group B had 0.7% greater A1C reduction than group C (p=0.0001).

Conclusion: ILI may decrease A1C by up to 2.5% in patients with diabetes. In patients with a similar magnitude of weight loss, A1C reduction was more prominent in those with higher baseline A1C levels. This may be valuable for clinicians to set realistic expectations of A1C reduction for their patients in response to ILI, which is usually the primary step in diabetes management.


A.H. Eldib: None. S. Tomah: Stock/Shareholder; Self; Amarin Corporation. A. Mottalib: None. S. Ashrafzadeh: None. O. Hamdy: Advisory Panel; Self; AstraZeneca, Sanofi-Aventis. Consultant; Self; Abbott, Merck & Co., Inc. Research Support; Self; National Dairy Council. Stock/Shareholder; Self; Healthimation, LLC.

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