Feasibility of Using a Factory-Calibrated Continuous Glucose Monitoring System to Diagnose Type 2 Diabetes.

Plasma glucose or A1C criteria can be used to establish the diagnosis of type 2 diabetes (T2D). We examined whether continuous glucose monitoring (CGM) data from a single 10-day wear period could form the basis of an alternative diagnostic test for T2D. We developed a binary classification diagnostic CGM (dCGM) algorithm using a dataset of 716 individual CGM sensor sessions from 563 participants with associated A1C measurements from seven clinical trials.

Adipocyte Proteins and Storage of Endogenous Fatty Acids in Visceral and Subcutaneous Adipose Tissue in Severe Obesity.

Objective: This study tested whether substrate concentrations or fatty acid storage proteins predict storage of endogenous lipids in visceral adipose tissue (VAT) and upper body subcutaneous adipose tissue (UBSQ) fat.

Methods: The day prior to surgery, 25 patients undergoing bariatric procedures received an infusion of autologous [1- C]triolein-labeled very low-density lipoprotein (VLDL) particles, and during surgery, they received a continuous [U- C]palmitate infusion/bolus [9,10- H]palmitate tracer. VAT and UBSQ fat were collected to measure VLDL-triglyceride (TG) storage, direct free fatty acid (FFA) storage rates, CD36 content, lipoprotein lipase (LPL), acyl-CoA synthetase, diacylglycerol acetyl-transferase, and glycerol-3-phosphate acyltransferase activities.

Regulation of direct adipose tissue free fatty acid storage during mixed meal ingestion and high free fatty acid concentration conditions.

We found that direct free fatty acid (FFA) storage (fatty acid cycling back into adipose tissue) in leg vs. abdominal subcutaneous fat is related to regional differences in adipose tissue diacylglycerol acyltransferase (DGAT) activity under high-FFA conditions and to differences in adipose tissue acyl-CoA synthetase (ACS)activity under meal ingestion conditions. We also found that direct FFA storage rates in leg fat were significantly less in physically active than sedentary adults.

Hepatic Fatty Acid Balance and Hepatic Fat Content in Humans With Severe Obesity.

Objective: Nonalcoholic fatty liver disease can lead to hepatic inflammation/damage. Understanding the physiological mechanisms that contribute to excess hepatic lipid accumulation may help identify effective treatments.

Design: We recruited 25 nondiabetic patients with severe obesity scheduled for bariatric surgery.

Effects of meal ingestion on intramyocellular ceramide concentrations and fractional de novo synthesis in humans.

We investigated the effects of meal ingestion on intramyofibrillar (IMF) and subsarcolemmal (SS) ceramide metabolism in volunteers ranging from lean to obese. Thirty-eight women and men underwent a steady-state meal ingestion protocol that included a 6.5-h infusion of [U-C]palmitate and muscle biopsies 1.

Randomized trial reveals that physical activity and energy expenditure are associated with weight and body composition after RYGB.

Objective: This study investigated the associations of both physical activity time (PA) and energy expenditure (EE) with weight and fat mass (FM) loss in patients following Roux-en-Y gastric bypass (RYGB) surgery.

Methods: Ninety-six nondiabetic patients were included in this analysis. Post-RYGB patients were randomized in one of two treatments: A 6-month exercise training program (RYBG+EX) or lifestyle educational classes (RYGB).

Intramyocellular Ceramides: Subcellular Concentrations and Fractional De Novo Synthesis in Postabsorptive Humans.

We investigated the relationship between insulin resistance markers and subsarcolemmal (SS) and intramyofibrillar (IMF) ceramide concentrations, as well as the contribution of plasma palmitate (6.5-h infusion of [U-C]palmitate) to intramyocellular ceramides. Seventy-six postabsorptive men and women had muscle biopsies 1.

Very-long-chain -3 fatty acid supplements and adipose tissue functions: a randomized controlled trial.

Increased omega-3 (n-3) fatty acid consumption is reported to benefit patients with metabolic syndrome, possibly due to improved adipose tissue function. We tested the effects of high-dose, very-long-chain ω-3 fatty acids on adipose tissue inflammation and insulin regulation of lipolysis. A double-blind, placebo-controlled study compared 6 mo of 3.

Resting and exercise energy metabolism in weight-reduced adults with severe obesity.

Objective: To determine effects of physical activity (PA) with diet-induced weight loss on energy metabolism in adults with severe obesity.

Methods: Adults with severe obesity (n = 11) were studied across 6 months of intervention, then compared with controls with less severe obesity (n = 7) or normal weight (n = 9). Indirect calorimetry measured energy metabolism during exercise and rest.

Effects of Dietary n-3 Fatty Acids on Hepatic and Peripheral Insulin Sensitivity in Insulin-Resistant Humans.

Objective: Dietary n-3 polyunsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), prevent insulin resistance and stimulate mitochondrial biogenesis in rodents, but the findings of translational studies in humans are thus far ambiguous. The aim of this study was to evaluate the influence of EPA and DHA on insulin sensitivity, insulin secretion, and muscle mitochondrial function in insulin-resistant, nondiabetic humans using a robust study design and gold-standard measurements.

Research Design And Methods: Thirty-one insulin-resistant adults received 3.

Clinical trial demonstrates exercise following bariatric surgery improves insulin sensitivity.

Background: Roux-en-Y gastric bypass (RYGB) surgery causes profound weight loss and improves insulin sensitivity (S(I)) in obese patients. Regular exercise can also improve S(I) in obese individuals; however, it is unknown whether exercise and RYGB surgery-induced weight loss would additively improve S(I) and other cardiometabolic factors.

Methods: We conducted a single-blind, prospective, randomized trial with 128 men and women who recently underwent RYGB surgery (within 1-3 months).

Effects of acute lipid overload on skeletal muscle insulin resistance, metabolic flexibility, and mitochondrial performance.

We hypothesized that acute lipid-induced insulin resistance would be attenuated in high-oxidative muscle of lean trained (LT) endurance athletes due to their enhanced metabolic flexibility and mitochondrial capacity. Lean sedentary (LS), obese sedentary (OS), and LT participants completed two hyperinsulinemic euglycemic clamp studies with and without (glycerol control) the coinfusion of Intralipid. Metabolic flexibility was measured by indirect calorimetry as the oxidation of fatty acids and glucose during fasted and insulin-stimulated conditions, the latter with and without lipid oversupply.

Free fatty acid uptake in humans with CD36 deficiency.

Animal models have demonstrated that CD36 facilitates cell membrane free fatty acid (FFA) transport, but its role in human metabolism is not well understood. We measured heart, liver, adipose (three depots), and muscle (truncal postural and thigh locomotive) FFA uptake using [(11)C]palmitate positron emission tomography (PET) scans in a family of five carrying the Pro90Ser CD36 mutation (2 homozygotes had no CD36) and matched control volunteers. PET scans were done under conditions of suppressed and slightly increased palmitate concentrations.

Body composition analysis by air displacement plethysmography in normal weight to extremely obese adults.

Objective: To compare body composition parameters estimated by air displacement plethysmography (ADP) to dual X-ray absorptiometry (DXA) in body mass index (BMI) classifications that include extremely obese (BMI ≥ 40.0 kg/m(2) ), and to examine if differences between analyses were influenced by BMI.

Methods: Fat-free mass (FFM, kg), fat mass (FM, kg), and body fat (BF, %) were analyzed with both technologies.

Contribution of very low-density lipoprotein triglyceride fatty acids to postabsorptive free fatty acid flux in obese humans.

Objective: In the fasting state, plasma free fatty acids (FFA) are thought to derive almost exclusively from adipose tissue lipolysis. However, there are mixed reports as to whether the spillover of fatty acids (FA) from very low-density lipoprotein triglyceride (VLDL-TG) hydrolysis contributes significantly to the plasma FFA pool. Because substantial VLDL-TG fatty acid spillover into the plasma FFA pool would profoundly impact the interpretation of isotope dilution measures of FFA flux, we investigated the contribution of VLDL-TG spillover to plasma FFA appearance.

Effect of physical activity on weight loss, energy expenditure, and energy intake during diet induced weight loss.

Objective: Objective measurements of physical activity (PA), energy expenditure (EE) and energy intake can provide valuable information regarding appropriate strategies for successful sustained weight loss.

Design And Methods: The total EE was examined by doubly labeled water, resting metabolic rate by indirect calorimetry, PA with activity monitors, and energy intake by the intake/balance technique in 116 severely obese undergoing intervention with diet alone (DO) or diet plus PA (D-PA).

Results: Weight loss of 9.

Effects of diet and physical activity interventions on weight loss and cardiometabolic risk factors in severely obese adults: a randomized trial.

Context: The prevalence of severe obesity is increasing markedly, as is prevalence of comorbid conditions such as hypertension and type 2 diabetes mellitus; however, apart from bariatric surgery and pharmacotherapy, few clinical trials have evaluated the treatment of severe obesity.

Objective: To determine the efficacy of a weight loss and physical activity intervention on the adverse health risks of severe obesity.

Design, Setting, And Participants: Single-blind randomized trial conducted from February 2007 through April 2010 at the University of Pittsburgh.