Effects of High-Protein Versus High-Carbohydrate Diets on Markers of β-Cell Function, Oxidative Stress, Lipid Peroxidation, Proinflammatory Cytokines, and Adipokines in Obese, Premenopausal Women Without Diabetes

Abstract

OBJECTIVETo study the effects of high-protein versus high-carbohydrate diets on various metabolic end points (glucoregulation, oxidative stress [dichlorofluorescein], lipid peroxidation [malondialdehyde], proinflammatory cytokines [tumor necrosis factor-α and interleukin-6], adipokines, and resting energy expenditure [REE]) with high protein–low carbohydrate (HP) and high carbohydrate–low protein (HC) diets at baseline and after 6 months of dietary intervention.RESEARCH DESIGN AND METHODSWe recruited obese, premenopausal women aged 20–50 years with no diabetes or prediabetes who were randomized to HC (55% carbohydrates, 30% fat, and 15% protein) or HP (40% carbohydrates, 30% fat, and 30% protein) diets for 6 months. The diets were provided in prepackaged food, which provided 500 kcal restrictions per day. The above metabolic end points were measured with HP and HC diet at baseline and after 6 months of dietary intervention.RESULTSAfter 6 months of the HP versus HC diet (12 in each group), the following changes were significantly different by Wilcoxon rank sum test for the following parameters: dichlorofluorescein (−0.8 vs. −0.3 µmol/L, P < 0.0001), malondialdehyde (−0.4 vs. −0.2 μmol/L, P = 0.0004), C-reactive protein (−2.1 vs. −0.8 mg/L, P = 0.0003), E-selectin (−8.6 vs. −3.7 ng/mL, P = 0.0007), adiponectin (1,284 vs. 504 ng/mL, P = 0.0011), tumor necrosis factor-α (−1.8 vs. −0.9 pg/mL, P < 0.0001), IL-6 (−1.3 vs. −0.4 pg/mL, P < 0.0001), free fatty acid (−0.12 vs. 0.16 mmol/L, P = 0.0002), REE (259 vs. 26 kcal, P < 0.0001), insulin sensitivity (4 vs. 0.9, P < 0.0001), and β-cell function (7.4 vs. 2.1, P < 0.0001).CONCLUSIONSTo our knowledge, this is the first report on the significant advantages of a 6-month hypocaloric HP diet versus hypocaloric HC diet on markers of β-cell function, oxidative stress, lipid peroxidation, proinflammatory cytokines, and adipokines in normal, obese females without diabetes.

Effects of a high-protein/low carbohydrate versus a standard hypocaloric diet on adipocytokine levels and insulin resistance in obese patients along 9months

“…4 on weight control, cardiovascular parameters, and adipokine levels (9)(10), similar to those of the Mediterranean diet (11,(12)(13)(14)(15), although the association has been less clear in studies of high-carbohydrate diets (16)(17)(18).…”

Benefits of a Paleolithic diet with and without supervised exercise on fat mass, insulin sensitivity, and glycemic control: a randomized controlled trial in individuals with type 2 diabetes

“…The increased adiponectin levels in the PD group may relate to weight loss, with increased protein intake as a contributing factor [44,45]. The unaltered hormone levels in the PD-EX group may indicate the increased plasma volume because of physical activity [46].…”

Remission of pre-diabetes to normal glucose tolerance in obese adults with high protein versus high carbohydrate diet: randomized control trial

“…Body composition, LM composition, FM, and bone mineral content were assessed. 7 The DXA Quality Assurance manual for the GCRC was used to standardize patient positioning and scan analysis.…”

“…26 Another important aspect of a HP diet is the antiinflammatory effect and decreased glucose area under the curve (AUC) compared with a HC diet as was shown in our previous study. 7 Other studies have demonstrated that hyperglycemia during glucose challenge or elevation of FFA 27 leads to activation of leukocytes and reactive oxygen species (ROS). We have also shown that hyperglycemia in vivo and in vitro activates T cells, increases inflammatory cytokines, lipid peroxidation, and ROS.…”