Differential effects of lifestyle interventions on continuous glucose monitoring metrics in persons with type 2 diabetes: a randomized cross-over trial

Background The effects of lifestyle on glucose metabolism significantly differ between individuals. Hyperglycemia in type 2 diabetes is driven by tissue-specific insulin resistance and reduced beta-cell capacity, whose relative contribution varies between persons, potentially affecting the impact of lifestyle interventions. We quantified effects of lifestyle on continuously measured glucose (CGM) metrics and evaluated how these differ between type 2 diabetes phenotypes. Methods Forty persons with type 2 diabetes wore a CGM for 11 periods of 4 days, of which 3 control and 4 duplicated intervention periods (2x low carbohydrate diet, 2x Mediterranean diet, 2x walking after each meal and 2x ‘active day’ (hourly 5-minute exercise bouts)). Tissue-specific insulin resistance and beta-cell function were quantified using an OGTT. A linear mixed effects model quantified lifestyle impact on CGM metrics. Results On overage, low carbohydrate diet, walking after meal and active day, but not the Mediterranean diet, resulted in lower mean glucose (7.74, 8.37, 8.40 and 8.70 mmol/L, respectively) as compared to control (8.66 mmol/L) in participants who did not restrict carbohydrate intake at baseline. Notably, the magnitude and direction of effects varied between individuals. For instance, the low carbohydrate diet had more beneficial effects for persons who had liver- or combined insulin resistance with poor beta-cell function than for individuals who only had poor beta-cell function. Conclusions On average, traditional lifestyle interventions improved CGM metrics within 4 days. Importantly, the effects appear to vary depending on the diabetes phenotype, thus pointing to the need for personalized lifestyle treatment. Dutch Trial Register : NL7848.