Dietary carbohydrate restriction improves insulin sensitivity, blood pressure, microvascular function, and cellular adhesion markers in individuals taking statins

Abstract

Statins positively impact plasma low-density lipoprotein cholesterol, inflammation and vascular endothelial function (VEF). Carbohydrate restricted diets (CRD) improve atherogenic dyslipidemia, and similar to statins, have been shown to favorably affect markers of inflammation and VEF. No studies have examined whether a CRD provides additional benefit beyond that achieved by habitual statin use. We hypothesized that a CRD (<50 g carbohydrate/d) for 6 weeks would improve lipid profiles and insulin sensitivity, reduce blood pressure, decrease cellular adhesion and inflammatory biomarkers, and augment VEF (flow-mediated dilation and forearm blood flow) in statin users. Participants (n = 21; 59.3 ± 9.3 y, 29.5 ± 3.0 kg/m(2)) decreased total caloric intake by approximately 415 kcal at 6 weeks (P < .001). Daily nutrient intakes at baseline (46/36/17% carb/fat/pro) and averaged across the intervention (11/58/28% carb/fat/pro) demonstrated dietary compliance, with carbohydrate intake at baseline nearly 5-fold greater than during the intervention (P < .001). Compared to baseline, both systolic and diastolic blood pressure decreased after 3 and 6 weeks (P < .01). Peak forearm blood flow, but not flow-mediated dilation, increased at week 6 compared to baseline and week 3 (P ≤ .03). Serum triglyceride, insulin, soluble E-Selectin and intracellular adhesion molecule-1 decreased (P < .01) from baseline at week 3, and this effect was maintained at week 6. In conclusion, these findings demonstrate that individuals undergoing statin therapy experience additional improvements in metabolic and vascular health from a 6 weeks CRD as evidenced by increased insulin sensitivity and resistance vessel endothelial function, and decreased blood pressure, triglycerides, and adhesion molecules.

Keywords: C-reactive protein; CRD; CRP; CVD; DBP; FMD; Flow mediated dilation; HDL-C; HOMA-IR; Human; IL; Inflammation; Insulin resistance; LDL-C; Low-carbohydrate diets; MCP-1; R-FBF; RH-FBF; SBP; TNF-α; VEF; Vascular endothelial function; carbohydrate restricted diet; cardiovascular disease; diastolic blood pressure; flow mediated dilation; high-density lipoprotein cholesterol; homeostatic model of assessment-insulin resistance; interleukin; low-density lipoprotein cholesterol; monocyte chemotactic protein-1; reactive hyperemia forearm blood flow; resting forearm blood flow; sE-Selectin; sICAM-1; sVCAM-1; soluble E-selectin; soluble intracellular adhesion molecule-1; soluble vascular cell adhesion molecule-1; systolic blood pressure; tumor necrosis factor-α; vascular endothelial function.