Effect of Low-Energy Diets Differing in Fiber, Red Meat, and Coffee Intake on Cardiac Autonomic Function in Obese Individuals With Type 2 Diabetes

Abstract

OBJECTIVEThe autonomic nervous system (ANS) regulates both the cardiovascular system and energy balance and is disturbed in diabetes and obesity. The effect of different approaches of caloric restriction on ANS function has not been assessed in individuals with diabetes. Thus, we sought to determine whether low-energy diets differing in fiber, red meat, and coffee intake exert differential effects on cardiac autonomic function. RESEARCH DESIGN AND METHODSIn this randomized parallel-group pilot trial, obese patients with type 2 diabetes were randomly allocated to consume either a diet high in cereal fiber, free of red meat, and high in coffee (n = 13) or a diet low in fiber, high in red meat, and coffee free (n = 15) over 8 weeks. Eight measures of heart rate variability (HRV) indicating vagal and/or sympathetic modulation over 3 h and inflammatory markers were determined during a hyperinsulinemic-euglycemic clamp. RESULTSAfter 8 weeks, both dietary interventions resulted in a mean weight loss of 5-6 kg, a mean decline in heart rate of 4-6 bpm, and improvement in vagally mediated HRV. However, the changes in HRV parameters from baseline to 8 weeks did not differ between the groups. In the entire study cohort, incremental HRV from baseline to 8 weeks was associated with enhanced oxidative glucose utilization (P < 0.05), but not with insulin sensitivity and inflammatory markers. CONCLUSIONSIn obese patients with type 2 diabetes, energy restriction per se over 8 weeks contributed to improved cardiac vagal function in relation to improved oxidative glucose utilization. This preliminary finding should be verified in a confirmatory trial. Cardiovascular autonomic neuropathy detected by reduced heart rate variability (HRV) affects ;20% of individuals with diabetes (1). HRV measures the fluctuations in autonomic inputs to the heart (2) and is considered a prognostic marker in various conditions including diabetes (1), metabolic syndrome (3), and cardiovascular disease (2). Spectral analysis of HRV indicates that efferent vagal activity is a major contributor to the high-frequency component, while the low-frequency component

Equivalent reductions in body weight during the Beef WISE Study: beef's role in weight improvement, satisfaction and energy

“…According to the 2015 Dietary Guidelines for Americans, eating patterns that include lower intake of red meats are associated with reduced risk of obesity . However, findings from randomized controlled trials largely find no detrimental impact of lean red meat consumption on markers of cardiometabolic health during weight loss and weight maintenance . Red meat is a major contributor to overall protein intake and represents 58% of all meat consumption in the United States .…”

“…Previous randomized clinical studies demonstrated that lean beef and pork can be effectively incorporated into dietary patterns for improving cardiometabolic health during weight maintenance conditions. At least two randomized clinical trials found that including red meat in energy‐restricted diets does not negatively influence weight loss or improvements in cardiometabolic health . However, previous weight loss intervention trials were limited by relatively small sample sizes, absence of a HP control diet with no red meat and the manipulation of multiple dietary components .…”

“…At least two randomized clinical trials found that including red meat in energy‐restricted diets does not negatively influence weight loss or improvements in cardiometabolic health . However, previous weight loss intervention trials were limited by relatively small sample sizes, absence of a HP control diet with no red meat and the manipulation of multiple dietary components . Therefore, this randomized equivalence trial in 120 adults with overweight/obesity was conducted to determine the impact of consuming two HP diets (1: ≥4 weekly servings of lean beef [B] vs. 2: no red meat consumption [NB]) on weight loss, body composition and cardiometabolic health during a 16‐week weight loss intervention.…”

Cardiac Autonomic Neuropathy in Diabetes: A Predictor of Cardiometabolic Events

“…ANS dysfunction and increased sympathetic activity have been directly correlated with obesity (Piestrzeniewicz et al, 2008; Straznicky et al, 2009; Lambert E. et al, 2010; Lambert G. W. et al, 2010). Moreover, weight reduction significantly improves HRV and reduces ANS imbalances (Karason et al, 1999; Maser et al, 2007; Nault et al, 2007; Perugini et al, 2010; Ravussin, 2010; Casellini et al, 2015, 2016; Ziegler et al, 2015a). To evaluate the ability to reverse autonomic imbalance, we examined sudomotor function and HRV measurements in obese patients undergoing bariatric surgery.…”

Cardiovascular autonomic neuropathy in the course of diabetes – the review of actual knowledge.

“…Zastosowanie diety ubogokalorycznej u otyłych pacjentów z T2DM przez 8 tygodni wiąże się z poprawą parasympatycznej regulacji rytmu serca niezależnie od konsumpcji czerwonego mięsa czy zawartości błonnika [30]. Z drugiej strony jednak nie można wykluczyć, że poszczególne składniki diety nie wywierają wpływu na układ autonomiczny a obserwowany efekt wynika jedynie ze zmniejszenia masy ciała pacjentów [31][32].…”