Open Access Original investigation

Leptin is associated with vascular endothelial function in overweight patients with type 2 diabetes

Tomoaki Morioka1*, Masanori Emoto1, Yuko Yamazaki1, Naoya Kawano1, Satoshi Imamura1, Ryutaro Numaguchi1, Hiromi Urata1, Koka Motoyama1, Katsuhito Mori1, Shinya Fukumoto1, Hidenori Koyama2, Tetsuo Shoji3 and Masaaki Inaba1

Author Affiliations

1 Departments of Metabolism, Endocrinology and Molecular Medicine, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan

2 Department of Internal Medicine, Division of Endocrinology and Metabolism, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan

3 Department of Geriatrics and Vascular Medicine, Osaka City University Graduate School of Medicine, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan

For all author emails, please log on.

Cardiovascular Diabetology 2014, 13:10  doi:10.1186/1475-2840-13-10

Published: 10 January 2014

Abstract

Background

The adipocyte-derived hormone leptin plays a key role in the regulation of appetite and body weight. Recent studies have suggested that leptin is also involved in the pathogenesis of obesity-related atherosclerosis and cardiovascular disease. In this study, we investigated the association of plasma leptin levels with vascular endothelial function in lean and overweight patients with type 2 diabetes.

Methods

One hundred seventy-one type 2 diabetic patients, of which 85 were overweight (body mass index (BMI) ≥ 25 kg/m2), were enrolled in this cross-sectional study. Plasma leptin concentrations were measured by enzyme-linked immunosorbent assay. Flow-mediated dilatation (FMD) of the brachial artery was measured to evaluate vascular endothelial function using ultrasound.

Results

No significant difference in FMD was found between the lean and overweight groups (7.0 ± 3.8% and 6.5 ± 3.6%, respectively; p = 0.354). FMD was negatively correlated with age (r = −0.371, p < 0.001) and serum creatinine levels (r = −0.236, p = 0.030), but positively correlated with BMI (r = 0.330, p = 0.002) and plasma leptin levels (r = 0.290, p = 0.007) in the overweight group. FMD was not associated with any parameters in the lean group. Multiple regression analysis including possible atherosclerotic risk factors revealed that the plasma leptin level (β = 0.427, p = 0.013) was independently associated with FMD in the overweight group (R2 = 0.310, p = 0.025), but not the lean group.

Conclusion

Plasma leptin levels are associated with vascular endothelial function in overweight patients with type 2 diabetes.

Keywords:
Leptin; Endothelial function; Overweight; Type 2 diabetes