Skin autofluorescence as a measure of advanced glycation endproduct deposition: a novel risk marker in chronic kidney disease

Diabetes-induced alterations in the extracellular matrix and their impact on myocardial function

Diabetes is an increasing public health problem that is expected to escalate in the future due to the growing incidence of obesity in the western world. While this disease is well known for its devastating effects on the kidneys and vascular system, diabetic individuals can develop cardiac dysfunction, termed diabetic cardiomyopathy, in the absence of other cardiovascular risk factors such as hypertension or atherosclerosis. While much effort has gone into understanding the effects of elevated glucose or altered insulin sensitivity on cellular components within the heart, significant changes in the cardiac extracellular matrix (ECM) have also been noted. In this review article we highlight what is currently known regarding the effects diabetes has on both the expression and chemical modification of proteins within the ECM and how the fibrotic response often observed as a consequence of this disease can contribute to reduced cardiac function.

Skin autofluorescence and the association with renal and cardiovascular risk factors in chronic kidney disease stage 3

BACKGROUND AND OBJECTIVES

Tissue advanced glycation end products (AGE) accumulation is a measure of cumulative metabolic stress. Assessment of tissue AGE by skin autofluorescence (SAF) correlates well with cardiovascular (CV) outcomes in diabetic, transplant, and dialysis patients, and may be a useful marker of CV risk in earlier stages of chronic kidney disease (CKD).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

1707 patients with estimated GFR 59 to 30 ml/min per 1.73 m(2) were recruited from primary care practices for the Renal Risk In Derby (RRID) study. Detailed medical history was obtained, and each participant underwent clinical assessment as well as urine and serum biochemistry tests. SAF was assessed (mean of three readings) as a measure of skin AGE deposition using a cutaneous AF device (AGE Reader™, DiagnOptics, Groningen, The Netherlands).

RESULTS

Univariate analysis revealed significant correlations between AF readings and several potential risk factors for cardiovascular disease (CVD) and progression of CKD. SAF readings (arbitrary units) were also significantly higher among males (2.8 ± 0.7 versus 2.7 ± 0.6), diabetics (3.0 ± 0.7 versus 2.7 ± 0.6), patients with evidence of self-reported CVD (2.9 ± 0.7 versus 2.7 ± 0.6), and those with no formal educational qualifications (2.8 ± 0.6 versus 2.6 ± 0.6; P < 0.01 for all). Multivariable linear regression analysis identified hemoglobin, diabetes, age, and eGFR as the most significant independent determinants of higher SAF (standardized coefficients -0.16, 0.13, 0.12, and -0.10, respectively; R(2) = 0.17 for equation).

CONCLUSION

Increased SAF is independently associated with multiple CV and renal risk factors in CKD 3. Long-term follow-up will assess the value of SAF as a predictor of CV and renal risk in this population.