Effects Of A Low-carbohydrate Diet And Walking Exercise On Inflammation In Type 2 Diabetes.

Abstract

Low-carbohydrate high-fat (LCHF) diets are regaining popularity for improving glucose control in patients with type 2 diabetes (T2D). However, largely based on studies in rodents and findings from cell culture models, concern still remains over the possible pro-inflammatory and cardiovascular risk consequences of consuming a diet high in fat. The well-recognized anti-inflammatory and cardioprotective properties of exercise makes it a potential adjuvant to therapeutic LCHF diets. PURPOSE: To determine the impact of a short-term 1) LCHF diet, 2) LCHF diet with daily post-meal walking (LCHF+PW) and 3) low-fat, low glycemic index “guidelines” (G) diet on glucose control, markers of cellular inflammation, and cardiovascular risk factors in patients with T2D. METHODS: Nine individuals with T2D (age: 63±9, HbA1c: 6.7±0.9, means±SD) completed three isocaloric 4-day controlled diet conditions in a randomized crossover design. The LCHF+PW diet included three daily 15-min post meal walks at a light-to-moderate intensity. Glucose profiles were assessed by continuous glucose monitoring. Fasting blood samples were obtained before and after each intervention to measure glucose and lipids. Cellular markers implicated in the pro-inflammatory effects of excess lipids, including monocyte toll-like receptor 2 (TLR2) and 4 (TLR4) and platelet-monocyte aggregates (PMA), were measured by flow cytometry. RESULTS: When compared to G (7.3±1.2 mmol/l), both the LCHF (6.6±1.3 mmol/l) and LCHF+PW (6.4±1.1 mmol/l) diets decreased the 4-day mean glucose concentrations (p<0.001). PMA count per ml increased significantly after G (+27±16%, p=0.02) but was not significantly altered after LCHF (+21±68%, p=0.06) or LCHF+PW (-0.1±42.5%; p=0.99). Median fluorescence intensity of TLR4 on CD16+ monocytes decreased by ~4.3% (p= 0.05) after the LCHF diet. No other significant changes were seen in monocyte TLR2 or TLR4 (all p≥0.106). CONCLUSIONS: As compared to a G diet, four days of a LCHF diet reduced hyperglycemia and improved some inflammatory markers in people with T2D. The addition of three daily post meal walks did not appear to further improve glycemic or inflammatory status. Funding from Canadian Institutes of Health Research (MSH-141980) and Medtronic Diabetes.