Weight change, glycemic control, and sulfonylurea use are determinants of either preservation or decline in microvascular function in patients with type 2 diabetes, according to study results published in Diabetologia.
Microvascular complications of diabetes have a substantial effect on the quality of life in affected individuals. Using data from participants recruited to the Surrogate Markers for Micro- and Macro-Vascular Hard Endpoints for Innovative Diabetes Tools (SUMMIT) program, researchers aimed to examine the determinants of endothelial-dependent and -independent microvascular function in people with diabetes.
The endothelial-dependent response to acetylcholine and the endothelial-independent response to sodium nitroprusside were measured in 154 individuals with type 2 diabetes (72.7% women) and 99 control patients without type 2 diabetes (58.6% women) using laser Doppler fluximetry. Follow-up assessments were repeated 3 years later (mean, 3.14±0.21 years).
Compared with control individuals, participants with type 2 diabetes had impaired endothelial-dependent (93.9 vs 111.9 for area under the response curve [AUC; arbitrary units × minute]; P <.001) and -independent responses (63.2 vs 75.1 AUC; P <.05) at baseline. The mean decline in microvascular function over follow-up was similar between groups, but there was significant heterogeneity within the groups with regard to magnitude and direction of change in function.
The strongest determinant of change in microvascular function in patients with and without type 2 diabetes was weight change over follow-up. A weight loss of ≥5% was associated with an attenuation of the decline in both endothelial-dependent and -independent microvascular function observed in individuals who maintained a stable weight (endothelial-dependent function: 1.2 AUC with weight loss vs -15.8 AUC with stable weight; endothelial-independent function: -4.5 AUC with weight loss vs -16.6 AUC with stable weight). In addition, patients who gained weight over follow-up had a greater decline in microvascular function (endothelial-dependent function: -37.8 AUC; P <.001 for trend). This trend was significant in participants with diabetes but not control participants.
Improvement of glycemic control was also associated with less decline in endothelial-dependent microvascular function (P =.03), such that a decrease in hemoglobin A1c was linked to better functioning, independent of weight change. In participants with diabetes, sulfonylurea use was associated with a greater decline in microvascular function compared with use of other therapies, after adjustment for the effect of hemoglobin A1c (adjusted P =.022).
The investigators noted that the observational nature of the study prevented the identification of a causal relationship.
“In conclusion, we have demonstrated that modest weight loss and good [glycemic] control are associated with less 3 year decline in microvascular function in people with diabetes,” the study authors wrote. “[W]e have demonstrated that a modest weight loss of only 5% attenuated the time-dependent decline of endothelial-dependent microvascular function over 3 years.”
Casanova F, Gooding KM, Shore AC, et al. Weight change and sulfonylurea therapy are related to 3 year change in microvascular function in people with type 2 diabetes [published online March 17, 2020]. Diabetologia. doi: 10.1007/s00125-020-05125-4