Association Between Self-reported Physical Activity and Skin Autofluorescence, a Marker of Tissue Accumulation of Advanced Glycation End Products in Adults With Type 1 Diabetes: A Cross-sectional Study

Abstract

Purpose: The accumulation of advanced glycation end products (AGEs) in local tissue is an important cause of low-grade inflammation and oxidative stress and is linked to late diabetic complications. Physical activity has various beneficial cardiometabolic effects in type 1 diabetes (T1D) and is associated with lower frequency of chronic complications of diabetes, although the specific mechanisms still remain unclear. The present study determines the association between self-reported physical activity and skin autofluorescence (AF), a marker of tissue accumulation of AGEs in adults with T1D.

Methods: We enrolled 119 patients (63 women), aged 34 years (interquartile range [IQR], 26-41 years), with T1D duration of 17 years (IQR, 12-25 years), glycosylated hemoglobin (HbA_1c) of 7.9% (IQR, 7.1%-8.9%) referred to an outpatient diabetes clinic. Patients with diabetes duration of <5 years, age >65 years, concomitant diabetic ketoacidosis, and severe complications that restrict physical activity (eg, diabetic foot, diabetic proliferative retinopathy, blindness) were excluded. Physical activity was measured with the short version of the International Physical Activity Questionnaire (IPAQ-SF), and raw scores were then log-transformed because of non-normality. The accumulation of AGEs in the skin was assessed on the basis of skin AF. Correlations between AF and various laboratory and clinical findings were assessed, and multivariate linear regression analysis was used to examine factors that influenced AGEs.

Findings: Skin AF correlated positively with age (Spearman's coefficient [Rs] = 0.47; P < 0.0001), HbA_1c (Rs = 0.30; P = 0.001), waist-to-hip ratio (WHR; Rs = 0.23; P = 0.02), and negatively with logIPAQ-SF (Rs = -0.28; P = 0.002). A stepwise multivariable linear regression analysis indicated age (β = 0.46; P < 0.0001), HbA_1c (β = 0.21; P = 0.01), and logIPAQ-SF score (β = -0.17; P = 0.04) as predictors of the skin AF after adjustment for sex and WHR (R² = 0.36; P < 0.0001).

Implications: Higher physical activity is related to lower accumulation of AGEs in patients with T1D. Our study provides new insight into the beneficial effects of physical activity in T1D according to tissue accumulation of AGEs.

Keywords: chronic complications; physical activity; skin autofluorescence; type 1 diabetes.