Comment on: Tsiakou et al. Arterial stiffness is inversely related to plasma adiponectin levels in young normotensive patients with type 1 diabetes. Diabetes Care 2013;36:734-736.

We read the article by Tsiakou et al. (1) with great interest. This study showed a negative association between plasma adiponectin concentrations and arterial stiffness in young type 1 diabetic patients without complications. However, we recently showed a positive association between plasma adiponectin concentrations and arterial stiffness in patients with type 2 diabetes (2). Adiponectin has anti-inflammatory and anti-atherosclerotic effects, and reduction of plasma adiponectin has been reported to contribute to atherogenesis (3). There are controversial debates on the association between adiponectin and arterial stiffness.

Aso et al. (4) showed that serum adiponectin levels were positively correlated with brachial-ankle pulse wave velocity in patients with type 2 diabetes, which is consistent with our study. In our study, plasma adiponectin concentrations were also positively associated with urine albumin-to-creatinine ratio (2). The subjects studied by Aso et al. and us were elderly, slightly obese, with some diabetes complications, and most of them also had other atherogenic diseases such as hypertension and dyslipidemia. However, in the study by Tsiakou et al. (1), subjects with cardiovascular disease, overt nephropathy, hypertension, and dyslipidemia were excluded. Further, their subjects were young, with normal BMI, and had fewer diabetes complications as compared with the subjects of Aso et al. and ours (2,4).

The severity of angiopathy, including macro- and microangiopathy due to diabetes and other atherogenic diseases, may affect the association between adiponectin and arterial stiffness. The inverse relationship between plasma adiponectin concentrations and arterial stiffness may not be observed in diabetic patients with advanced angiopathy. Increased plasma adiponectin concentration has been reported to be independently associated with major adverse cardiovascular events in type 2 diabetic patients with coronary artery disease (5), supporting our hypothesis. To understand the association between adiponectin and arterial stiffness more precisely, we should perform studies investigating adiponectin and pulse wave velocity in diabetic patients and evaluating severity of angiopathy in the future.