Effects of Glutamine on Gastric Emptying of Low- and High-Nutrient Drinks in Healthy Young Subjects—Impact on Glycaemia

Abstract

Glutamine is a potent stimulus for the release of glucagon-like peptide-1, which increases postprandial insulin and slows gastric emptying (GE). We determined the effects of glutamine on GE of, and glycaemic responses to, low- and high-nutrient drinks in eight healthy males (mean age 21.6 ± 0.7 years and BMI 22.9 ± 0.7 kg/m2). Participants were studied on four occasions on which they consumed either a low-nutrient (beef soup; 18 kcal) or high-nutrient (75 g dextrose; 255 kcal) drink, each with or without 30 g of glutamine (120 kcal), in a randomised, crossover design. GE (2D ultrasound), blood glucose and plasma insulin concentrations were measured concurrently. Glutamine slowed GE (half emptying time (T50)) of both low- (45 ± 3 min vs. 26 ± 2 min, p < 0.001), and high-nutrient, (100 ± 5 min vs. 77 ± 5 min, p = 0.03) drinks, however, there was no effect on GE of the high nutrient drinks when expressed as kcal/min (3.39 ± 0.21 kcal/min vs. 3.81 ± 0.20 kcal/min, p = 0.25). There was no change in blood glucose after the low-nutrient drinks with or without glutamine, despite a slight increase in plasma insulin with glutamine (p = 0.007). The rise in blood glucose following the high-nutrient drink (p = 0.0001) was attenuated during the first 60 min by glutamine (p = 0.007). We conclude that in healthy subjects, glutamine slows GE of both low- and high-nutrient drinks comparably and attenuates the rise in blood glucose after the high-nutrient glucose drink.

Does glutamine supplementation have favorable effects on glucose control and insulin sensitivity?

“…Mean duration of the interventions were 19 days. Three studies were performed in women (Dock-Nascimento et al, 2012a, 2012bLaviano et al, 2014), five on men (Caris et al, 2014;Krzywkowski et al, 2001;Letellier et al, 2013;Du et al, 2018;Torres-Santiago et al, 2017) and nine trials involved both sexes (Mansour et al, 2015;Torres-Santiago et al, 2017;Cavalcante et al, 2012;Cui et al, 2014;Darmaun et al, 2004;Duska et al, 2008;Lomivorotov et al, 2013;Rotovnik Kozjek et al, 2011;Rotovnik Kozjek et al, 2017;Singh et al, 2015). The mean FBS, insulin level and HOMA-IR at baseline were 92.61 mg/dl, 11.93 units and 1.81 units, respectively, in the intervention group, and 94.08 mg/dl, 14.95 units and 1.87 units, respectively, in the placebo group.…”

“…The mean FBS, insulin level and HOMA-IR at baseline were 92.61 mg/dl, 11.93 units and 1.81 units, respectively, in the intervention group, and 94.08 mg/dl, 14.95 units and 1.87 units, respectively, in the placebo group. Studies were conducted in: Asia (three studies) (Mansour et al, 2015;Cui et al, 2014;Singh et al, 2015), America (six studies) (Dock-Nascimento et al, 2012a, 2012bCaris et al, 2014;Torres-Santiago et al, 2017;Cavalcante et al, 2012), Australia (two studies) (Du et al, 2018) and Europe (eight studies) (Laviano et al, 2014;Letellier et al, 2013;Krzywkowski et al, 2001;Darmaun et al, 2004;Duska et al, 2008;Lomivorotov et al, 2013; Rotovnik NFS 50,1 Kozjek et al, 2011). Six studies were performed in a cross-over manner (Laviano et al, 2014;Krzywkowski et al, 2001;Letellier et al, 2013;Du et al, 2018;Torres-Santiago et al, 2017;Darmaun et al, 2004).…”

“…Studies were conducted in: Asia (three studies) (Mansour et al, 2015;Cui et al, 2014;Singh et al, 2015), America (six studies) (Dock-Nascimento et al, 2012a, 2012bCaris et al, 2014;Torres-Santiago et al, 2017;Cavalcante et al, 2012), Australia (two studies) (Du et al, 2018) and Europe (eight studies) (Laviano et al, 2014;Letellier et al, 2013;Krzywkowski et al, 2001;Darmaun et al, 2004;Duska et al, 2008;Lomivorotov et al, 2013; Rotovnik NFS 50,1 Kozjek et al, 2011). Six studies were performed in a cross-over manner (Laviano et al, 2014;Krzywkowski et al, 2001;Letellier et al, 2013;Du et al, 2018;Torres-Santiago et al, 2017;Darmaun et al, 2004). Studies were conducted between 2001 and 2018.The selected trials included population with diverse health status.…”

“…Studies were conducted between 2001 and 2018.The selected trials included population with diverse health status. They included patients with Type 2 diabetes (Mansour et al, 2015;Lomivorotov et al, 2013), rectal cancer (Rotovnik Kozjek et al, 2011;Rotovnik Kozjek et al, 2017), healthy, obese and overweight patients (Laviano et al, 2014;Caris et al, 2014;Krzywkowski et al, 2001;Du et al, 2018), cystic fibrosis patients (Darmaun et al, 2004), patients who were candidates for elective laparoscopic cholecystectomy (Dock-Nascimento et al, 2012a, 2012b, multiple trauma patients (Duska et al, 2008), patients with systemic inflammatory response syndrome (Cavalcante et al, 2012), patients with Type 1 diabetes (Torres-Santiago et al, 2017), patients undergoing maxillofacial surgery and colonic resection (Cui et al, 2014;Singh et al, 2015) and children with Duchenne muscular dystrophy (Letellier et al, 2013). The quality of eligible studies is provided in Table I.…”

“…The results of quality assessment are provided in Table I Laviano et al, 2014;Du et al, 2018;Cui et al, 2014;Lomivorotov et al, 2013;Rotovnik Kozjek et al, 2017;Singh et al, 2015). Allocation concealment has been described in all trials except four trials which were unknown (Du et al, 2018;Cui et al, 2014;Lomivorotov et al, 2013;Singh et al, 2015).…”