Uncomplicated human type 2 diabetes is associated with meal-induced blood pressure lowering and cardiac output increase Mark M. Smits a, * , Marcel H.A. Muskiet a , Maarten E. Tushuizen a , Kelly A.A. Kwa a , John M. Karemaker b , Danie ¨l H. van Raalte a , Michaela Diamant a,1 a Diabetes Center/Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands b Department of Systems Physiology, Academic Medical Center, Amsterdam, The Netherlands 1. Introduction The postprandial state is associated with changes in systemic hemodynamics, including a decrease in blood pressure (BP) and an increase in heart rate (HR) [1–5]. When systolic BP (SBP) drops 20 mmHg, the term ‘postprandial hypotension’ (PPH) is used [6]. Severe reductions in BP can lead to dizziness, light- headedness and syncope [7] following a meal. Populations vulnerable to PPH include elderly subjects, patients with d i a b e t e s r e s e a r c h a n d c l i n i c a l p r a c t i c e 1 0 6 ( 2 0 1 4 ) 6 1 7 – 6 2 6 a r t i c l e i n f o Article history: Received 2 May 2014 Received in revised form 11 August 2014 Accepted 15 September 2014 Available online 7 October 2014 Keywords: Type 2 diabetes Metabolic syndrome Postprandial hemodynamics Autonomic nervous system a b s t r a c t Aims: Since many type 2 diabetes patients experience postprandial hypotension, the aim of this study was to unravel meal-related changes in systemic hemodynamics and autonomic nervous system (ANS)-balance. Methods: Forty-two age-matched males (15 type 2 diabetes; 12 metabolic syndrome; 15 controls) without overt autonomic neuropathy received a standardized high-fat mixed meal after an overnight fast. Hemodynamic variables were measured by finger plethysmography. Fourier analysis was used to calculate the low-/high-frequency (LF/HF)-ratio, a marker of autonomic nervous system-balance, and baroreceptor reflex sensitivity (BRS). Results: Following the meal, diastolic blood pressure (DBP) decreased in type 2 diabetes patients only, paralleled by a significant decrement in systemic vascular resistance (SVR) and an increase in cardiac index. All groups showed an increase in postprandial heart rate. Controls, but not metabolic syndrome or type 2 diabetes patients, showed a meal-related increase in LF/HF-ratio. When combining all study subjects, homeostatic model assess- ment-insulin resistance (HOMA-IR) was inversely correlated with changes in DBP, SVR, LF/ HF-ratio and BRS. Conclusions: Based on these data, we hypothesize that in patients with uncomplicated type 2 diabetes, insulin resistance hampers adequate meal-induced sympathetic activation, lead- ing to a decrease in SVR and resulting in a postprandial drop in DBP. # 2014 Elsevier Ireland Ltd. All rights reserved. * Corresponding author. Tel.:+31 20 444 0541; fax: +31 20 444 0542. E-mail address: mm.smits1@vumc.nl (M.M. Smits). 1 Deceased. Contents available at ScienceDirect Diabetes Research and Clinical Practice journal homepage: www.elsevier.com/locate/diabres http://dx.doi.org/10.1016/j.diabres.2014.09.044 0168-8227/# 2014 Elsevier Ireland Ltd. All rights reserved.