A 16-week randomized controlled trial of a fish oil and whey protein-derived supplement to improve physical performance in older adults losing autonomy-A pilot study.

Background: Low functional capacity may lead to the loss of independence and institutionalization of older adults. A nutritional intervention within a rehabilitation program may attenuate loss of muscle function in this understudied population.

Objective: This pilot study assessed the feasibility for a larger RCT of a nutritional supplementation in older adults referred to an outpatient assessment and rehabilitation program.

Acute hyperaminoacidemia does not suppress insulin-mediated glucose turnover in healthy young men.

Elevated circulating amino acids (AA) concentrations are purported to cause insulin resistance (IR) in humans. To quantify hyperaminoacidemia effects on insulin-mediated glucose turnover in healthy men, we performed 2-stage pancreatic clamps using octreotide with glucagon and growth hormone replacement. In the basal stage, insulin was infused to maintain euglycemia at postabsorptive levels.

Leucine Supplementation Does Not Alter Insulin Sensitivity in Prefrail and Frail Older Women following a Resistance Training Protocol.

Background: Frailty is a clinical condition associated with loss of muscle mass and strength (sarcopenia). Although sarcopenia has multifactorial causes, it might be partly attributed to a blunted response to anabolic stimuli. Leucine acutely increases muscle protein synthesis, and resistance training (RT) is the strongest stimuli to counteract sarcopenia and was recently shown to improve insulin sensitivity (IS) in frail older women.

Neurocognitive and Hormonal Correlates of Voluntary Weight Loss in Humans.

Insufficient responses to hypocaloric diets have been attributed to hormonal adaptations that override self-control of food intake. We tested this hypothesis by measuring circulating energy-balance hormones and brain functional magnetic resonance imaging reactivity to food cues in 24 overweight/obese participants before, and 1 and 3 months after starting a calorie restriction diet. Increased activity and functional connectivity in prefrontal regions at month 1 correlated with weight loss at months 1 and 3.

Academic stress and personality interact to increase the neural response to high-calorie food cues.

Psychosocial stress is associated with an increased intake of palatable foods and weight gain in stress-reactive individuals. Personality traits have been shown to predict stress-reactivity. However, it is not known if personality traits influence brain activity in regions implicated in appetite control during psychosocial stress.

Insulin resistance of protein anabolism accompanies that of glucose metabolism in lean, glucose-tolerant offspring of persons with type 2 diabetes.

Objective: To test whether protein anabolic resistance is an early defect in type 2 diabetes (T2D).

Research Design And Methods: Seven lean, normoglycemic T2D offspring (T2D-O) and eight matched participants without family history (controls; C) underwent a 3-hour hyperinsulinemic (40 mU/m/min), euglycemic (5.5 mmol/L) and isoaminoacidemic clamp.

Adiponectin-SOGA Dissociation in Type 1 Diabetes.

Context: Circulating adiponectin is elevated in human type 1 diabetes (T1D) and nonobese diabetic (NOD) mice without the expected indications of adiponectin action, consistent with tissue resistance.

Objective: Adiponectin stimulates hepatocyte production of the suppressor of glucose from autophagy (SOGA), a protein that inhibits glucose production. We postulated that due to tissue resistance, the elevation of adiponectin in T1D should fail to increase the levels of a surrogate marker for liver SOGA, the circulating C-terminal SOGA fragment.

Protein and glucose metabolic responses to hyperinsulinemia, hyperglycemia, and hyperaminoacidemia in obese men.

Objective: In insulin-resistant states, resistance of protein anabolism occurs concurrently with that of glucose, but can be compensated for by abundant amino acid (AA) provision. This effect and its mechanism were sought in obesity.

Methods: Pancreatic clamps were performed in 8 lean and 11 obese men, following 5-h postabsorptive, 3-h infusions of octreotide, basal glucagon, and growth hormone, with clamped postprandial-level insulin, glucose, and AA.

Malignant transformation of a solitary fibrous tumor of the liver and intractable hypoglycemia.

Sarcomas of the liver are rare. We report a case of intractable hypoglycemia secondary to a solitary fibrous tumor that underwent malignant transformation into a fibrosarcoma. A 70-year-old man presented with a hepatic mass and tumor-associated hypoglycemia which was resistant to medical management.

Determinants of whole-body protein metabolism in subjects with and without type 2 diabetes.

Objective: Whole-body protein metabolism is abnormal in suboptimally controlled type 2 diabetes and obesity. We hypothesized that glycemia, insulin resistance, and waist circumference modulate these alterations in type 2 diabetes and, to a lesser extent, in individuals without type 2 diabetes.

Research Design And Methods: In 88 lean and obese subjects without and 40 with type 2 diabetes on an inpatient protein-controlled isoenergetic diet for 7 days, whole-body protein turnover was measured using the fed-fasted 60-h oral (15)N-glycine method.

Influence of adiposity in the blunted whole-body protein anabolic response to insulin with aging.

Background: Although insulin resistance of glucose is often reported with aging, that of protein metabolism is still debated. We tested if the insulin sensitivity of protein metabolism parallels that of glucose and is altered with aging.

Methods: Whole-body (13)C-leucine and (3)H-glucose kinetics were measured in the postabsorptive state and during an hyperinsulinemic, euglycemic, isoaminoacidemic clamp in 12 young men (age: 27 +/- 1 years; body mass index [BMI]: 23 +/- 1 kg/m(2)), 11 young women (age: 25 +/- 1 years; BMI: 21 +/- 1 kg/m(2)), 9 elderly men (age: 70 +/- 1 years; BMI: 26 +/- 1 kg/m(2)), and 10 elderly women (age: 69 +/- 2 years; BMI: 23 +/- 1 kg/m(2)).

The influence of sex on the protein anabolic response to insulin.

We hypothesize that sex influences whole-body protein anabolism in the postabsorptive state and in response to hyperinsulinemia. Kinetics of 3-(3)H-glucose and (13)C-leucine were studied in 16 men and 15 women after energy- and protein-controlled diets, before and during a hyperinsulinemic, euglycemic, isoaminoacidemic clamp. In the postabsorptive state, women had 20% higher rates of leucine Ra (protein breakdown) and nonoxidative Rd (synthesis) adjusted for fat-free mass than men but net leucine balance was as negative.

Whole-body protein anabolic response is resistant to the action of insulin in obese women.

Background: Obesity is associated with insulin resistance of glucose and lipid metabolism.

Objective: We sought to determine the effects of obesity on the insulin sensitivity of protein metabolism.

Design: Whole-body [(13)C]leucine and [(3)H]glucose kinetics were measured in 9 lean and 10 obese women in the postabsorptive state and during a hyperinsulinemic, euglycemic, isoaminoacidemic clamp.

Increase in the thermic effect of food in women by adrenergic amines extracted from citrus aurantium.

Objective: To compare the thermic response to a meal between men and women of varied body composition and to determine whether adrenergic amines extracted from citrus aurantium (CA) induce an increase in metabolic rate and enhance the thermic response to the meal.

Research Methods And Procedures: In 30 healthy weight-stable subjects (17 women, 13 men; BMI: 20 to 42 kg/m2), body composition was determined by bioimpedance analysis followed by resting energy expenditure for 20 minutes, and the thermic effect of food (TEF) of a 1.7-MJ, 30-gram protein meal was determined intermittently for 300 minutes by indirect calorimetry.