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Background: Although insulin secretion after carbohydrate ingestion is severely impaired in patients with type 2 diabetes, amino acid and protein co-ingestion can substantially increase plasma insulin responses. Objective: We investigated insulin responses and the subsequent plasma glucose disposal rates after the ingestion of carbohydrate alone (CHO) or with a protein hydrolysate and amino acid mixture (CHO+PRO) in patients with a long-term diagnosis of type 2 diabetes. Design: Ten type 2 diabetic patients [mean ([+ or -]SEM) age: 62 [+ or -] 2 y; body mass index (kg/[m.sup.2]): 27 [+ or -] 1] and 9 healthy control subjects (age: 58 [+ or -] 1 y; body mass index: 27 [+ or -] 1) participated in 2 trials in which the plasma insulin response was measured after the ingestion of 0.7 g carbohydrate x [kg.sup.-1] x [h.sup.-1] with or without 0.35 g. [kg.sup.-1] [h.sup.-1] of a mixture that contained a protein hydrolysate, leucine, and phenylalanine. Continuous infusions with [6,[6-.sup.2][H.sub.2]]glucose were then given to investigate plasma glucose disposal. Results: Plasma insulin responses were higher by 299 [+ or -] 64% and 132 + 63% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The subsequent plasma glucose responses were reduced by 28 [+ or -] 6% and 33 [+ or -] 3% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The reduced plasma glucose response in the diabetic patients was attributed to a 13 [+ or -] 3% increase in glucose disposal (P < 0.01). Conclusions: The combined ingestion of carbohydrate with a protein hydrolysate and amino acid mixture significantly increases de novo insulin production in patients with a long-term diagnosis of type 2 diabetes. The increased insulin response stimulates plasma glucose disposal and reduces postprandial glucose concentrations. KEY WORDS Glucose disposal, protein hydrolysate, leucine, phenylalanine, metabolism, type 2 diabetes

OBJECTIVE -- Insulin secretion in response to carbohydrate intake is blunted in type 2 diabetic patients. However, it is not clear whether the insulin response to other stimuli, such as [...]

Results demonstrate that physical activity performance improves with the intake of propranolol and caffeine than with propanolol alone. However, the improvement is not linked to increases in lipolytic activity or lowering of plasma potassium concentration.

Background: Little is known about physical activity and mortality risk in the elderly. Therefore, we describe the associations between the physical activity pattern of elderly men and the mortality from cardiovascular diseases (CVDs), particularly coronary heart disease (CHD) and stroke, and all causes. Methods: Self-reported physical activity was assessed with a validated questionnaire for retired men in a population-based sample of 802 Dutch men, aged 64 to 84 years at baseline. Relative risks were estimated for 10-year mortality from CVD (199 deaths), CHD (90), stroke (47), and all causes (373) for tertiles of time spent: on physical activity (reference, lowest tertile). Adjustments were made for baseline age, relevant major chronic diseases, cigarette smoking, and alcohol consumption. Results: Mortality risks from CVD and all causes decreased with increasing physical activity (P for trend = .04) with adjusted relative risks of 0.70 (95% confidence interval, 0.48-1.01) and 0.77 (95% confidence interval, 0.591.00) in the highest tertile of total physical activity, respectively. Except for CHD, time spent in more intense activities ([is greater than or equal to] 4 kcal/kg per hour) was more strongly associated with all mortality outcomes than less intense activities, but no single type of activity was particularly protective. Walking or cycling at least 3 times per week for 20 minutes (our definition of activity based on general health recommendations) was associated with reduced mortality from CVD (adjusted relative risk, 0.69; 95% confidence interval, 0.50-0.88) and all causes (relative risk, 0.71; 95% confidence interval, 0.58-0.88). Additional adjustment for biological cardiovascular risk factors did not affect the strength of any association. Conclusion: In a general population of elderly men, physical activity may protect against mortality from CVDs and all causes. Arch Intern Med. 1998; 158:1499-1505

The aim of this study was to investigate the effect of medium-chain triacylglycerol (MCT) ingestion during exercise on subsequent time-trial cycling performance. Seven well-trained cyclists performed four exercise trials consisting of 2 h at 60% of maximal oxygen uptake followed by a simulated time trial (ie, completion of a preset amount of work as fast as possible) of [approximately equals] 15 min duration. During the trials, subjects ingested 1) a 10% carbohydrate solution (CHO; 170 [+ or -] 6 g glucose), 2) a 10% carbohydrate electrolyte with 5% MCT solution (CHO + MCT; 85 [+ or -] 3 g MCT), 3) a 5% MCT solution, or 4) artificially colored and flavored water (placebo). Neither CHO nor CHO + MCT ingestion had any effect on performance compared with placebo ingestion, whereas ingestion of MCT had a negative effect on performance. Average work rates during the time trial were 314 [+ or -] 19, 314 [+ or -] 13, and 312 [+ or -] 18 with CHO, CHO + MCT, and placebo, respectively, and was 17-18% lower in the MCT trial (263 [+ or -] 22 W). In addition, compared with placebo ingestion, MCT ingestion had no effect on total rates of fat or carbohydrate oxidation, nor did it affect exogenous or endogenous carbohydrate utilization. The negative effect of MCT ingestion was associated with increased gastrointestinal complaints (ie, intestinal cramping). These data suggest that large amounts of MCTs (85 g) ingested during prolonged submaximal exercise may provoke gastrointestinal problems leading to decreased exercise performance. Am J Clin Nutr 1998;67:397-404.

Intervention studies have shown that the adaptation of fat oxidation to fat intake, when the dietary fat content is changed, is not abrupt. This study was conducted to measure the time course of adaptation of oxidation rates to increases in the fat content of the diet while subjects were fed at energy balance. Twelve healthy, nonobese males and females [age: 26 [+ or -] 2 y, body mass index (in k g/[m.sup.2]): 21.4 [+ or -] 0.5; and habitual fat intake: 29 [+ or -] 1% of energy] consumed a low-fat diet for 6 d (days 1-6) followed by a high-fat diet for 7 d (days 7-13). Days 5-9 and 13 were spent in a respiration chamber. After adjustment for energy intake to 24-h energy expenditure on day 5, subjects were in energy balance (range: -0.15 to 0.23 kJ/d) on days 6-9 and 13. Fat balance was zero on day 6 but became positive after subjects changed to the high-fat diet (1.06 [+ or -] 0.15, 0.75 [+ or -] 0.15, and 0.55 [+ or -] 0.14 MJ/d for days 7, 8, and 9, respectively, P [is less than] 0.05), reaching a new balance on day 13, 7 d afterward. In conclusion, when in energy balance, lean subjects are capable of adjusting fat oxidation to fat intake within 7 d of when dietary fat content is increased. Am J Clin Nutr 1997;66:276-82.

The relationship between sleeping metabolic rate (SMR) measured from 0300 to 0600 h in a respiration chamber and body composition was studied in 47 healthy adult subjects (23 men and 24 women). The effect of the menstrual cycle on SMR was examined in 16 to the 24 women. SMR increased in the postovulation phase of the menstrual cycle (estimated as days 18-29 after last menstruation) 7.7% on average (P < 0.001). A stepwise regression showed that both fat-free mass (FFM), fat mass (FM), and the phase of the menstrual cycle contributed significantly to SMR. After adjustment for FFM and FM, no sex differences in SMR (men vs preovulation women) remained. The inclusion of FM in this model is an improvement that eliminates the sex difference in SMR/FFM that is usually found. A prediction equation is given that explains 85% of the variance in SMR among individuals.

A 12-wk weight-management program was conducted to test the effectiveness of a combined very-low-calorie diet (VLCD) [2.0 MJ/d (470 kcal/d)] (week 1-5) and exercise (E) program supervised by each patient's general practitioner and dietitian. Throughout the program, patients [body mass index measured in kg/[m.sup.2] (BMI) 27-351 were encouraged to take part in an individually graded E program of walking (W), cycling (C), running (R), or swimming (S) (Van Baak and Binkhorst 1981). Ninety-four patients (65 female and 29 male, weight: 87.7 kg, BMI: 30.7, age: 39.8 y) completed the program ([delta]: - 10.6 kg). At the start, 46% were not involved in any type of physical exercise. After 12 wk only 8% were inactive (Drop out group (n = 14): 47%). Weight loss over 12 wk was significantly (P < 0.0 1) related to participation rate in the E program. Also, 24-wk follow-up showed a significantly better (P < 0.05) weight maintenance for patients who continued the E program (+O.4 vs + 1.8 kg). These data demonstrate the effectiveness of a weight-management program including exercise in primary health care. Am J Clin Nutr 1992;56:294S-6S.