Does prior acute exercise affect postexercise substrate oxidation in response to a high carbohydrate meal?

<p>Abstract</p> <p>Background</p> <p>Consumption of a mixed meal increases postprandial carbohydrate utilization and decreases fat oxidation. On the other hand, acute endurance exercise increases fat oxidation and decreases carbohydrate utilization during the post-exercise recovery period. It is possible that the resulting post-exercise increase in circulating nonesterified fatty acids could attenuate the ability of ingested carbohydrate to inhibit lipid oxidation. The purpose of this study was to determine whether prior exercise attenuates the usual meal-induced decline in lipid oxidation.</p> <p>Methods</p> <p>Six healthy, physically active young subjects (x age = 26.3 years, 4 males, 2 females) completed three treatments in random order after a ~10 h fast: (a) Exercise/Carbohydrate (Ex/CHO) – subjects completed a bout of exercise at 70% VO_2peak(targeted net energy cost of 400 kcals), followed by consumption of a carbohydrate-rich meal; (b) Exercise/Placebo (Ex/Placebo) – subjects completed an identical bout of exercise followed by consumption of a placebo; and (c) No Exercise/Carbohydrate (NoEx/CHO) – subjects sat quietly rather than exercising and then consumed the carbohydrate-rich meal. Blood samples were obtained before and during the postprandial period to determine plasma glucose, insulin, and non-esterified fatty acids (NEFA). Respiratory gas exchange measures were used to estimate rates of fat and carbohydrate oxidation.</p> <p>Results</p> <p>Plasma NEFA were approximately two-fold higher immediately following the two exercise conditions compared to the no-exercise condition, while meal consumption significantly increased insulin and glucose in both Ex/CHO and NoEx/CHO. NEFA concentrations fell rapidly during the 2-h postprandial period, but remained higher compared to the NoEx/CHO treatment. Carbohydrate oxidation increased rapidly and fat oxidation decreased in response to the meal, with no differences in the rates of carbohydrate and fat oxidation during recovery between the Ex/CHO and NoEx/CHO conditions.</p> <p>Conclusion</p> <p>The plasma NEFA concentration is increased during the post exercise period, which is associated with elevated fat oxidation when no meal is consumed. However, when a mixed meal is consumed immediately following exercise, the initially elevated plasma NEFA concentration decreases rapidly, and postexercise fat oxidation during this 2-h postexercise, postprandial period is no higher than that of the 2-h postprandial period without prior exercise.</p

Closed-loop insulin delivery for treatment of type 1 diabetes

Type 1 diabetes is one of the most common endocrine problems in childhood and adolescence, and remains a serious chronic disorder with increased morbidity and mortality, and reduced quality of life. Technological innovations positively affect the management of type 1 diabetes. Closed-loop insulin delivery (artificial pancreas) is a recent medical innovation, aiming to reduce the risk of hypoglycemia while achieving tight control of glucose. Characterized by real-time glucose-responsive insulin administration, closed-loop systems combine glucose-sensing and insulin-delivery components. In the most viable and researched configuration, a disposable sensor measures interstitial glucose levels, which are fed into a control algorithm controlling delivery of a rapid-acting insulin analog into the subcutaneous tissue by an insulin pump. Research progress builds on an increasing use of insulin pumps and availability of glucose monitors. We review the current status of insulin delivery, focusing on clinical evaluations of closed-loop systems. Future goals are outlined, and benefits and limitations of closed-loop therapy contrasted. The clinical utility of these systems is constrained by inaccuracies in glucose sensing, inter- and intra-patient variability, and delays due to absorption of insulin from the subcutaneous tissue, all of which are being gradually addressed.Supported by the Juvenile Diabetes Research Foundation (#22-2006-1113, #22-2007-1801, #22-2009-801), Diabetes UK (BDA07/0003549, BDA07/0003551), European Commission Framework Programme 7 (247138), NIDDK (DK085621), and NIHR Cambridge Biomedical Research Centre

The Complete Designers' Lights II

The private collection of Galerie kreo's founders Clémence and Didier Krzentowski, featuring some 500 light -- now in an expanded & updated new edition Clémence and Didier Krzentowski – the founders and directors of the leading contemporary design Galerie kreo – have been collecting lights for 30 years. Focusing particularly on Italian and French design, their collection is the most important of its kind today, spanning creations from the 1950s to the 1990s. It includes large groups of works by Paulin, Guariche, Castiglioni, and the biggest collection of Sarfatti. Conceived as a catalogue raisonné of nearly 500 lights, this book also includes a discussion between Didier Krzentowski, the design historian and Director of the Bordeaux Musée des Arts décoratifs et du Design, Constance Rubini, and the journalist and design critic Pierre Doze. Also featured is an essay by the design and art critic Alex Coles focusing on the relationship between light design and light art, mainly through a parallel study of Gino Sarfatti’s and Dan Flavin’s work

Another look at the implications of the DCCT study

The fundamental role of good metabolic control has been demonstrated in type 1 and type 2 diabetes. Nevertheless, clinicians often wonder why some patients under good metabolic control develop complications while others remain free of such complications, despite a poorly controlled disease. The present study revisited material from the DCCT database, by classifying the 1441 patients as being under good or poor metabolic control if their HbA(1c) mean level fell in the lower (HbA(1c)less than or equal to56.9%) or upper (HbA(1c)greater than or equal to9.5%) quintile of the overall distribution of mean HbA(1c) levels observed in the DCCT population. The impact of metabolic control and of other potential factors related to the patient and his/her disease on the development and/or deterioration of complications, in particular diabetic retinopathy and nephropathy, was assessed. Although metabolic control is the major determinant of the risk of developing diabetic retinopathy and nephropathy, the study also emphasizes the significant role of other risk factors, in particularly BMI, disease duration, micro-albuminuria, HbA(1c) at baseline, gender and age on such complications. It is concluded that early control of the metabolic and clinical status of diabetic patients has major consequences on the evolution of the disease. Nomograms have been proposed to help the clinician in this task

Factors predictive of nephropathy in DCCT Type 1 diabetic patients with good or poor metabolic control

peer reviewedAims The study aim was to assess the time-related risk of developing diabetic nephropathy [albumin excretion rate (AER) greater than or equal to 40 mg/24 h] from baseline covariates in Type 1 diabetic patients with either good or poor metabolic control (MC). Methods Based on material from the Diabetes Control and Complications Trial study (n = 1441), patients were considered as under good or poor MC if their HbA(1c) mean level up to last visit fell in the lowest (less than or equal to 6.9%) or highest (greater than or equal to 9.5%) quintile of the overall HbA(1c) distribution, respectively. Prevalence cases of nephropathy were excluded from the study. Survival analysis and Cox regression were applied to the data. Results Among patients with good MC (n = 277), 15% had developed nephropathy at the end of the study. Conversely, among patients with poor MC (n = 268), the proportion without the complication was 52%. When adjusting for MC, time to diabetic nephropathy was related to age (P < 0.0001), AER (P < 0.001), duration of diabetes (P < 0.005), body mass index (BMI) (P < 0.005), all at baseline, and to gender (P < 0.01). Patients with upper normal range AER levels, longer duration of diabetes and lower BMI were at higher risk, regardless of MC. The adverse effect of younger age on diabetic nephropathy was more marked in good than in poor MC. Although women tended to develop the complication more often under good MC, they appeared to be better protected under poor MC. Conclusions This study confirms occurrence of diabetic nephropathy under good MC and non-occurrence of the complication despite poor MC. It also demonstrates that some baseline covariates can affect, in a differential manner, time to diabetic nephropathy depending on MC

Lack of benefit from the intermittent administration of insulin in treatment using subcutaneous perfusion pump in type 1 diabetes

Our study is based on two constatations: 1) Hyperinsulinaemia, a possible atherogenic factor, is frequent under continuous subcutaneous insulin infusion. 2) Pulsatile intravenous insulin delivery improve the insulin's hypoglycaemic activity. To test if equivalent metabolic control can be obtained with a reduced intermittent subcutaneous infused insulin dose, we compared nocturnal metabolic control of 8 c-peptide negative type 1 diabetic patients under three experimental conditions: Continuous usual dose test (1.0 +/- 0.1 u/h); Intermittent half dose test (1.0 +/- 0.1 u/h, 30 min/h); Continuous half dose test (0.5 +/- 0.05 u/h) Five parameters were monitored: blood glucose, plasma free insulin and beta-hydroxy-butyrate, free fatty acid and glycerol plasma level. No significant differences were found between intermittent and continuous half-dose tests. We conclude that, in our experimental conditions, intermittent subcutaneous insulin infusion does not reduce the metabolic degradation induced by insulin dose reduction

A 6-hour nocturnal interruption of a continuous subcutaneous insulin infusion: 1. Metabolic and hormonal consequences and scheme for a prompt return to adequate control.

Interruption of a continuous subcutaneous insulin infusion, most often due to technical problems occurring during the night, is a not uncommon event whose metabolic consequences have received relatively little attention until now. We have therefore investigated the changes in blood glucose, plasma non-esterified fatty acids, 3-hydroxybutyrate, glucagon and free insulin in eight C-peptide negative Type 1 diabetic patients whose pumps were deliberately stopped between 23.00 h and 05.00 h. A control test with the pump functioning normally was carried out in each patient and the studies were randomized. Considering the values at 23.00 h as reference, interruption of the insulin infusion resulted in (1) a rapid decrease in plasma free insulin significant after 1 h and reaching a nadir of 6 +/- 2 mU/l after 6 h; (2) a rise in blood glucose which was significant at hour 3 and reached 17.4 +/- 1.9 mmol/l at hour 6; (3) a moderate increase in plasma nonesterified fatty acids which remained in the range of 700-800 mumol/l; (4) an early and linear rise in plasma 3-hydroxybutyrate, significant after 1 h and averaging 1290 +/- 140 mumol/l after 6 h; (5) a late increase (hour 5) in plasma glucagon. The second aim of our study was to provide for the patient a precise scheme of insulin supplements administered via the pump and based on blood glucose monitoring (Dextrostix - Glucometer) and semi-quantitative evaluation of ketonuria (Acetest). Resetting the pump at its basal rate at 05.00 h and giving insulin supplements (2-8 U) at 06.45 h (with the usual breakfast dose) and again at 10.00 h have proved efficacious in restoring satisfactory metabolic control by noon the day after starting the experiment. These results form practical recommendations to patients undergoing this type of accident