The acute effects of dietary carbohydrate reduction on postprandial responses of non-esterified fatty acids and triglycerides: a randomized trial

Amirsalar Samkani,Christian Anholm,Thure Krarup,Mads J Skytte,Carolyn F Deacon,Ray Boston,Arne Astrup,Sten Madsbad,Steen B Haugaard,Jens J Holst

doi:10.1186/s12944-018-0953-8

Abstract

BackgroundPostprandial non-esterified fatty acid (NEFA) and triglyceride (TG) responses are increased in subjects with type 2 diabetes mellitus (T2DM) and may impair insulin action and increase risk of cardiovascular disease and death. Dietary carbohydrate reduction has been suggested as non-pharmacological therapy for T2DM, but the acute effects on NEFA and TG during subsequent meals remain to be investigated.MethodsPostprandial NEFA and TG responses were assessed in subjects with T2DM by comparing a carbohydrate-reduced high-protein (CRHP) diet with a conventional diabetes (CD) diet in an open-label, randomized, cross-over study. Each diet was consumed on two consecutive days, separated by a wash-out period. The iso-caloric CRHP/CD diets contained 31/54 E% from carbohydrate, 29/16 E% energy from protein and 40/30 E% from fat, respectively. Sixteen subjects with well-controlled T2DM (median HbA1c 47 mmol/mol, (37–67 mmol/mol) and BMI 30 ± 4.4 kg/m2) participated in the study. NEFA and TG were evaluated following breakfast and lunch.ResultsNEFA net area under curve (AUC) was increased by 97 ± 38 μmol/Lx270 min (p = 0.024) after breakfast but reduced by 141 ± 33 μmol/Lx180 min (p < 0.001) after lunch on the CRHP compared with CD diet. Likewise, TG net AUC was increased by 80 ± 28 μmol/Lx270 min (p = 0.012) after breakfast but reduced by 320 ± 60 μmol/Lx180 min (p < 0.001) after lunch on the CRHP compared with CD diet.ConclusionsIn well-controlled T2DM a modest reduction of dietary carbohydrate with a corresponding increase in protein and fat acutely reduced postprandial serum NEFA suppression and increased serum TG responses after a breakfast meal but had the opposite effect after a lunch meal. The mechanism behind this second-meal phenomenon of CRHP diet on important risk factors for aggravating T2DM and cardiovascular disease awaits further investigation.Trial registrationThe study was registered at clinicaltrials.gov ID: NCT02472951. https://clinicaltrials.gov/ct2/show/NCT02472951. Registered June 16, 2015.

Highlights

Postprandial non-esterified fatty acid (NEFA) and triglyceride (TG) responses are increased in subjects with type 2 diabetes mellitus (T2DM) and may impair insulin action and increase risk of cardiovascular disease and death
Postprandial glucose and insulin area under curve (AUC) were reduced by 14 and 22%, respectively, by the carbohydrate-reduced high-protein (CRHP) compared with the conventional diabetes (CD) diet
Suppression of NEFA was more pronounced on CD resulting in a less total AUC of NEFA compared with CRHP diet (Fig. 1, Table 2)

Summary

Introduction

Postprandial non-esterified fatty acid (NEFA) and triglyceride (TG) responses are increased in subjects with type 2 diabetes mellitus (T2DM) and may impair insulin action and increase risk of cardiovascular disease and death. Non-esterified fatty acids (NEFAs) and triglycerides are present in the circulation in varying quantities dependent on food - and body composition, insulin resistance and glucose tolerance [1,2,3]. In T2DM, dietary management with concomitant body weight loss is suggested to be the basis of prevention and treatment to reduce comorbidities such as cardiovascular disease [10, 11]. The higher content of fat in carbohydrate-reduced diets could in theory induce higher postprandial concentrations of NEFA and triglycerides (TG)

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