The Resistance Exercise in Already Active Diabetic Individuals (READI) Randomized Clinical Trial.

CONTEXT: Resistance exercise training (strength training) and aerobic exercise training are both recommended for people with type 1 diabetes, but it is unknown whether adding resistance exercise provides incremental benefits in people with this condition who already perform aerobic exercise regularly. OBJECTIVE: This work aimed to evaluate the incremental effect of resistance training on glycated hemoglobin A1c (HbA1c), fitness, body composition, and cardiometabolic risk factors in aerobically active people with type 1 diabetes. METHODS: The Resistance Exercise in Already-active Diabetic Individuals (READI) trial (NCT00410436) was a 4-center, randomized, parallel-group trial. After a 5-week run-in period with diabetes management optimization, 131 aerobically active individuals with type 1 diabetes were randomly assigned to resistance exercise (n = 71, intervention-INT) or control (n = 60, CON) for 22 additional weeks. Both groups maintained their aerobic activities and were provided dietary counseling throughout. Exercise training was 3 times per week at community-based facilities. The primary outcome was HbA1c, and secondary outcomes included fitness (peak oxygen consumption, muscle strength), body composition (anthropometrics, dual-energy x-ray absorptiometry, computed tomography), and cardiometabolic risk markers (lipids, apolipoproteins). Assessors were blinded to group allocation. RESULTS: There were no significant differences in HbA1c change between INT and CON. Declines in HbA1c (INT: 7.75 ± 0.10% [61.2 ± 1.1 mmol/mol] to 7.55 ± 0.10% [59 ± 1.1 mmol/mol]; CON: 7.70 ± 0.11% [60.7 ± 1.2 mmol/mol] to 7.57 ± 0.11% [59.6 ± 1.3 mmol/mol]; intergroup difference in change -0.07 [95% CI, -0.31 to 0.18]). Waist circumference decreased more in INT than CON after 6 months (P = .02). Muscular strength increased more in INT than in CON (P < .001). There were no intergroup differences in hypoglycemia or any other variables. CONCLUSION: Adding resistance training did not affect glycemia, but it increased strength and reduced waist circumference, in aerobically active individuals with type 1 diabetes.

Glucose and protein metabolic responses to an energy- but not protein- restricted diet in type 2 diabetes.

AIMS: To test the effect of energy restriction with maintained protein intake on body composition and on insulin sensitivity of glucose and protein metabolism in adults with type 2 diabetes (T2D). MATERIALS AND METHODS: After 3 days of an isoenergetic diet with 1.2 g/kg/d protein, obese adults with T2D (three women, two men) followed a 5-week diet providing 60% of energy requirements with 45% carbohydrate, and with protein maintained at pre-intervention level. Isotopic tracers were used to quantify whole-body glucose (3-3 H-glucose) and protein (13 C-leucine) metabolism pre- (day 4) and post-intervention (day 39), in the postabsorptive state and during a hyperinsulinaemic, isoglycaemic, isoaminoacidaemic clamp. Body composition was measured using dual-energy x-ray absorptiometry. RESULTS: After energy restriction, 6% weight loss occurred via total body (11%) and visceral fat losses (25%), but lean mass was preserved. Fasting glucose level, serum insulin level, homeostatic model assessment of insulin resistance index and C-peptide level decreased significantly (29%, 38%, 54% and 38%, respectively) as did other cardiometabolic risk factors. Between clamp studies, postabsorptive protein turnover and oxidation rates decreased (12% and 32%), resulting in less negative net balance, consistent with protein conservation. The rates of glucose turnover decreased, and glucose metabolic clearance rate improved (24%). During the clamp, protein flux was lower (9%) and breakdown suppressed (12%), and net balance became less negative but not different. Although glucose turnover did not differ, metabolic clearance improved by 47%. CONCLUSIONS: In obese adults with T2D, an energy-restricted diet with maintained protein intake of ~1.2 g/kg/d improved the kinetics of protein metabolism (particularly in the postabsorptive state), and preserved lean body mass and increased glucose metabolic clearance rate.

Plasma Amino Acids vs Conventional Predictors of Insulin Resistance Measured by the Hyperinsulinemic Clamp.

CONTEXT: Specific plasma amino acid (AA) profiles including elevated postabsorptive branched-chain amino acids (BCAAs) have been associated with insulin resistance (IR), mostly estimated by homeostatic model assessment. This study assessed the associations of postabsorptive AAs with IR directly measured by insulin-mediated glucose disposal and determined the quantitative value of AAs and conventional IR predictors. DESIGN: Fifty-one healthy, 31 overweight or obese (Ow/Ob), and 52 men and women with type 2 diabetes (T2D) were studied retrospectively. The main outcome measures were the glucose disposal (M/I) index (using 3-[3H]-glucose) during a hyperinsulinemic-euglycemic clamp and whole-body protein turnover (using 1-[13C]-leucine). RESULTS: Compared with healthy participants, M/I was lower in Ow/Ob participants and lowest in those with T2D. BCAAs, glutamate, and lysine were higher in the Ow/Ob and T2D groups than in healthy participants; glycine and threonine were lower. Most AAs were higher in men. Principal component analysis identified component 1 (C1: BCAAs, methionine) and C3 (glycine, threonine, serine). Glutamate, C1, ornithine, lysine, methionine, and tyrosine correlated negatively with M/I; C3 and glycine correlated positively. Waist circumference and sex strongly influenced AA-IR relationships; only glutamate correlated after these factors were controlled for. From regression analysis, waist circumference, fasting glucose, insulin, and free fatty acids (FFAs) negatively predicted 64% of the M/I variance; glutamate added 2% more. In nondiabetic participants, IR was predicted by waist circumference, insulin, and FFAs, without contribution from AAs. CONCLUSION: Several postabsorptive AAs correlated with IR but added limited predictive value to conventional markers because levels were determined largely by abdominal adiposity. Data suggest a sex-specific regulation of AA metabolism by excess adiposity, particularly the BCAAs, warranting investigation.

Does exercise training affect resting metabolic rate in adolescents with obesity?

We evaluated the hypothesis that resistance exercise training performed alone or in combination with aerobic exercise training would increase resting metabolic rate (RMR) relative to aerobic-only and nonexercising control groups. Postpubertal adolescents (N = 304) aged 14-18 years with obesity (body mass index (BMI) ≥ 95th percentile) or overweight (BMI ≥ 85th percentile + additional diabetes risk factor(s)) were randomized to 4 groups for 22 weeks: Aerobic exercise training, Resistance exercise training, Combined aerobic and resistance exercise training, or Control. All participants received dietary counselling targeting a daily energy deficit of 250 kcal. RMR was measured by indirect calorimetry and body composition by magnetic resonance imaging. There was no significant change in RMR in any group, in spite of significant within-group increases in fat-free mass in the Aerobic, Resistance, and Combined exercise training groups. RMR at baseline and 6 months were Aerobic: 1972 ± 38 and 1990 ± 41; Resistance: 2024 ± 37 and 1992 ± 41; Combined: 2023 ± 38 and 1995 ± 38; Control: 2075 ± 38 and 2073 ± 39 kcal/day (p > 0.05). There were no between-group differences in RMR after adjustment for total body weight or fat-free mass between groups over time. Per-protocol analyses including only participants with ≥70% adherence, and analyses stratified by sex, also showed no within- or between-group differences in RMR. In conclusion, despite an increase in fat-free mass in all exercise groups, 6 months of aerobic, resistance, or combined training with modest dietary restriction did not increase RMR compared with diet only in adolescents with obesity.

Effects of aerobic training, resistance training, or both on cardiorespiratory and musculoskeletal fitness in adolescents with obesity: the HEARTY trial.

The purpose of this study was to examine the effects of aerobic, resistance, and combined exercise training on cardiorespiratory and musculoskeletal fitness in postpubertal adolescents with obesity. After a 4-week supervised moderate-intensity exercise run-in, 304 adolescents aged 14-18 years with body mass index ≥85th percentile were randomized to 4 groups for 22 weeks of aerobic training, resistance training, combined training, or a nonexercising control. All participants received dietary counselling with a maximum daily energy deficit of 250 kcal. Cardiorespiratory fitness (peak oxygen consumption) was measured by indirect calorimetry using a graded treadmill exercise test. Musculoskeletal fitness was measured using the 2003 Canadian Physical Activity Fitness and Lifestyle Appraisal tests (hand grip, push-ups, partial curl-ups, sit and reach, and vertical jump). Muscular strength was assessed using an 8-repetition maximum test on the bench press, seated row, and leg press machines. A greater increase in peak oxygen consumption in the aerobic exercise group (30.6 ± 0.6 to 33.4 ± 0.7 mLO2/kg/min) was measured relative to the control group (30.6 ± 0.5 to 30.9 ± 0.7 mLO2/kg/min) (p = 0.002). Similarly, the number of partial curl-ups increased in the aerobic group (19 ± 1 to 23 ± 1) while no differences were measured in the control group (19 ± 1 to 20 ± 1) (p = 0.015). Increases in muscular strength and number of push-ups were greatest in the resistance group versus the control and combined groups versus the aerobic group (p < 0.05). In conclusion, aerobic training had the strongest effect on cardiorespiratory fitness, while resistance and combined training improved both muscular strength and endurance more than control and aerobic training alone, respectively, in adolescents with obesity.

Effects of aerobic training, resistance training, or both on psychological health in adolescents with obesity: The HEARTY randomized controlled trial.

OBJECTIVE: To determine the effects of aerobic training, resistance training, and combined training on mood, body image, and self-esteem in adolescents with obesity. METHOD: After a 4-week prerandomization treatment, 304 postpubertal adolescents (91 males, 213 females) with obesity ages 14-18 years were randomized to 1 of 4 groups for 22 weeks: aerobic training (n = 75), resistance training (n = 78), combined aerobic and resistance training (n = 75), or nonexercising control (n = 76). All participants received dietary counseling, with a daily energy deficit of 250 kcal. Mood was measured using the Brunel Mood Scale. Body image was assessed using the Multiple Body Self-Relations Questionnaire, and physical self-perceptions and global self-esteem were measured using the Harter Physical Self-Perceptions Questionnaire. RESULTS: Median adherence was 62%, 56%, and 64% in aerobic, resistance, and combined training, respectively. Resistance and combined training produced greater improvements than control on vigor, and resistance training reduced depressive symptoms. All groups improved on body image and physical self-perceptions, but combined showed greater increases than control on perceived physical conditioning, while only resistance training showed greater increases than controls on global self-esteem. Both combined and resistance training demonstrated greater increases in perceived strength than control. Psychological benefits were more related to better adherence and reductions in body fat than changes in strength or fitness. CONCLUSION: Resistance training, alone or in combination with aerobic training, may provide psychological benefits in adolescents with overweight or obesity, and therefore could be an alternative to aerobic training for some individuals in the biological and psychological management of adolescent obesity.

Effect of obesity and type 2 diabetes on protein anabolic response to insulin in elderly women.

Obesity and type 2 diabetes have been shown to alter the insulin sensitivity of glucose and protein metabolism in middle-aged women. We aimed to determine whether these findings translate to the elderly who are at increased risk of muscle loss. We assessed whole-body protein (1-(13)C-leucine) and glucose (3-(3)H-glucose) kinetics in 10 healthy (age: 71.6±1.8years; BMI: 23.2±0.8kg/m(2)), 8 obese (age: 72.9±1.3; BMI: 33.1±1.0) and 8 obese well-controlled type 2 diabetic (age: 69.8±1.6; BMI: 34.4±1.5) elderly women in the postabsorptive state and during a hyperinsulinemic, euglycemic, isoaminoacidemic clamp. All subjects followed an isoenergetic, protein-controlled diet for 6days preceding the clamp. The net protein anabolic response to hyperinsulinemia was similarly blunted in obese (0.08±0.06) and obese type 2 diabetic women (0.06±0.04) compared to healthy women (0.24±0.05µmol·kg fat free mass(-1)·min(-1); ANOVA p=0.018). In contrast, the insulin-mediated glucose disposal (healthy: 9.72±0.67) was decreased with obesity (6.96±0.86) and further with diabetes (5.23±0.27mg·kg fat free mass(-1)·min(-1); ANOVA p<0.001). Endogenous glucose production was not completely suppressed during the clamp only in diabetic women. Thus, the glucose infusion rate was the lowest in this group. Obese elderly women with and without type 2 diabetes have a similar degree of insulin resistance of protein anabolism, despite worse glucose metabolism in type 2 diabetes. Similar to previous findings in middle-aged women, obesity exerted a blunting effect on protein anabolism, which may contribute to the development of sarcopenic obesity. Our results suggest that the presence of type 2 diabetes at an advancing age does not further aggravate this effect.

Effect of 10% dietary protein intake on whole body protein kinetics in type 2 diabetic adults.

BACKGROUND & AIMS: Insulin resistance of protein metabolism occurs in obesity and type 2 diabetes (T2D). Hyperaminoacidemia during a simulated fed steady-state clamp compensates for this resistance. We tested whether decreasing protein intake affects the response to insulin with or without added amino acids, and if this response differs by sex. METHODS: Protein intake was reduced from usual (15%) to 10% of an isoenergetic diet energy for 11 days, in T2D obese men (n = 8) and women (n = 10). Whole-body leucine kinetics (1-(13)C-leucine, surrogate for protein) were determined postabsorptive and during a hyperinsulinemic (∼600 pmol/L), hyperglycemic (8 mmol/L), isoaminoacidemic, followed by hyperaminoacidemic clamp and compared to those of T2D men on a 17% protein diet. RESULTS: Initial negative nitrogen balance approached equilibrium by day 10 but remained lower than with the 17% protein diet. During the hyperinsulinemic, isoaminoacidemic clamp, total leucine flux was less, with both lower endogenous rates of appearance (catabolism) and nonoxidative rates of disposal (synthesis), resulting in net balance at zero. With hyperaminoacidemia, net balance increased to 0.39 ± 0.09 µmol/kgLBM⋅min in men, significantly less than in men on 17% protein (0.98 ± 0.09, p < 0.01). There were no sex differences in clamp responses with 10% protein. CONCLUSIONS: After 11 days of 10% protein diet, there was a slight improvement in insulin sensitivity, but a blunted anabolic response to hyperaminoacidemia. Longer-term consequences of lesser anabolic efficiency at reduced protein intakes require study and may contribute to increased risk of sarcopenia in persons with T2D with aging.

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. Whole-body [1-(13) C]-leucine and [3-(3) H]-glucose kinetics, skeletal muscle protein ((2) H5 -phenylalanine) fractional synthesis rates, and insulin signaling were determined. RESULTS: Clamp Δ insulin and Δ branched-chain AA did not differ; fasting glucagon and growth hormone were maintained. Glucose uptake was 20% less in obese concurrent with less Akt(Ser473) , but also less IRS-1(Ser636/639) phosphorylation. Stimulation of whole-body, myofibrillar, and sarcoplasmic protein synthesis was similar. Whole-body protein catabolism suppression tended to be less (P=0.06), resulting in lesser net balance (1.09 ± 0.07 vs. 1.31 ± 0.08 µmol [kg FFM(-1) ] min(-1) , P=0.048). Increments in muscle S6K1(Thr389) phosphorylation were less in the obese, but 4E-BP1(Ser65) did not differ. CONCLUSIONS: Hyperaminoacidemia with hyperinsulinemia stimulated protein synthesis (possibly via nutrient signaling) normally in obesity, but suppression of proteolysis may be compromised. Whether long-term high protein intakes could compensate for the insulin resistance of protein anabolism remains to be determined.

Participants' perceptions of a group based program incorporating hands-on meal preparation and pedometer-based self-monitoring in type 2 diabetes.

BACKGROUND: Nutrition education (portion sizes, balanced meals) is a cornerstone of diabetes management; however, moving from information to behavior change is challenging. Through a single arm intervention study, we recently demonstrated that combining education with group-based meal preparation training has measureable effects on weight, eating behaviour, and glycemic control in adults with type 2 diabetes. In the present study, we conducted an in-depth examination of participants' perceptions of this strategy, through focus group discussion, to delineate effective elements of the strategy from participants' perspectives. METHODS: Participants who had completed the nutrition education/meal preparation training program were invited to attend one of four focus group discussions. These were led by experienced facilitators and guided by questions addressing experiences during the intervention and their perceived impact. Audiotapes were transcribed and qualitative content analysis of transcripts was performed. We report herein themes that achieved saturation across the four discussions. RESULTS: Twenty-nine (80.6%, 29/36) attended a focus group discussion. The program elements perceived as effective by participants included the hands-on interactive learning approach to meal preparation, the grocery store tour, pedometer-based self-monitoring, experiencing the link between food consumption/physical activity and glucose changes during the program, and peer support. Discussants reported changes in eating and walking behaviour, greater confidence in ability to self-manage diabetes, reductions in glucose levels and/or need for glucose-lowering medications, and, in some cases, weight loss. Family members and friends were facilitators for some and barriers for others in terms of achieving health behavior changes. CONCLUSIONS: Among adults with type 2 diabetes, a group based program that included hands-on meal preparation and pedometer-based self-monitoring was perceived as effective in conveying information, developing skills, building confidence, and changing health behaviors.

Effects of aerobic training, resistance training, or both on percentage body fat and cardiometabolic risk markers in obese adolescents: the healthy eating aerobic and resistance training in youth randomized clinical trial.

IMPORTANCE: Little evidence exists on which exercise modality is optimal for obese adolescents. OBJECTIVE: To determine the effects of aerobic training, resistance training, and combined training on percentage body fat in overweight and obese adolescents. DESIGN, SETTING, AND PARTICIPANTS: Randomized, parallel-group clinical trial at community-based exercise facilities in Ottawa (Ontario) and Gatineau (Quebec), Canada, among previously inactive postpubertal adolescents aged 14 to 18 years (Tanner stage IV or V) with body mass index at or above the 95th percentile for age and sex or at or above the 85th percentile plus an additional diabetes mellitus or cardiovascular risk factor. INTERVENTIONS: After a 4-week run-in period, 304 participants were randomized to the following 4 groups for 22 weeks: aerobic training (n = 75), resistance training (n = 78), combined aerobic and resistance training (n = 75), or nonexercising control (n = 76). All participants received dietary counseling, with a daily energy deficit of 250 kcal. MAIN OUTCOMES AND MEASURES: The primary outcome was percentage body fat measured by magnetic resonance imaging at baseline and 6 months. We hypothesized that aerobic training and resistance training would each yield greater decreases than the control and that combined training would cause greater decreases than aerobic or resistance training alone. RESULTS: Decreases in percentage body fat were -0.3 (95% CI, -0.9 to 0.3) in the control group, -1.1 (95% CI, -1.7 to -0.5) in the aerobic training group (P = .06 vs controls), and -1.6 (95% CI, -2.2 to -1.0) in the resistance training group (P = .002 vs controls). The -1.4 (95% CI, -2.0 to -0.8) decrease in the combined training group did not differ significantly from that in the aerobic or resistance training group. Waist circumference changes were -0.2 (95% CI, -1.7 to 1.2) cm in the control group, -3.0 (95% CI, -4.4 to -1.6) cm in the aerobic group (P = .006 vs controls), -2.2 (95% CI -3.7 to -0.8) cm in the resistance training group (P = .048 vs controls), and -4.1 (95% CI, -5.5 to -2.7) cm in the combined training group. In per-protocol analyses (≥ 70% adherence), the combined training group had greater changes in percentage body fat (-2.4, 95% CI, -3.2 to -1.6) vs the aerobic group (-1.2; 95% CI, -2.0 to -0.5; P = .04 vs the combined group) but not the resistance group (-1.6; 95% CI, -2.5 to -0.8). CONCLUSIONS AND RELEVANCE: Aerobic, resistance, and combined training reduced total body fat and waist circumference in obese adolescents. In more adherent participants, combined training may cause greater decreases than aerobic or resistance training alone. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00195858.

The transcultural diabetes nutrition algorithm: a canadian perspective.

The Transcultural Diabetes Nutrition Algorithm (tDNA) is a clinical tool designed to facilitate implementation of therapeutic lifestyle recommendations for people with or at risk for type 2 diabetes. Cultural adaptation of evidence-based clinical practice guidelines (CPG) recommendations is essential to address varied patient populations within and among diverse regions worldwide. The Canadian version of tDNA supports and targets behavioural changes to improve nutritional quality and to promote regular daily physical activity consistent with Canadian Diabetes Association CPG, as well as channelling the concomitant management of obesity, hypertension, dyslipidemia, and dysglycaemia in primary care. Assessing glycaemic index (GI) (the ranking of foods by effects on postprandial blood glucose levels) and glycaemic load (GL) (the product of mean GI and the total carbohydrate content of a meal) will be a central part of the Canadian tDNA and complement nutrition therapy by facilitating glycaemic control using specific food selections. This component can also enhance other metabolic interventions, such as reducing the need for antihyperglycaemic medication and improving the effectiveness of weight loss programs. This tDNA strategy will be adapted to the cultural specificities of the Canadian population and incorporated into the tDNA validation methodology.

Nutritional education through internet-delivered menu plans among adults with type 2 diabetes mellitus: pilot study.

BACKGROUND: A potential barrier to weight loss and vascular risk reduction is difficulty in operationalizing dietary education into a concrete plan. Although a variety of Internet-based software tools are now available to address this issue, there has been little formal evaluation of these tools. OBJECTIVE: The aim of this single-arm pilot study is to determine the effect of a 24-week Internet-based menu-planning program, by examining pre- to postintervention changes in the body weight, blood pressure, and glycemia, specifically among overweight adults with type 2 diabetes mellitus (DM2), a clinical population at high risk for vascular diseases. METHODS: A total of 33 adults with DM2 were recruited by collaborating registered dietitians to a 24-week Internet-based menu-planning program. Individualized dietary prescriptions were operationalized into weekly Internet-delivered menu plans through an adapted version of a commercially available service. Adherence was defined as logging into the program at least once per week for a minimum of 18 of the 24 weeks. Multiple imputations were used for missing data. Using baseline and postintervention assessments, we calculated the weight changes (mean, 95% CI) and investigated the corresponding effects (linear regression models) on blood pressure (systolic, diastolic) and hemoglobin A1C (ie, glycemia). RESULTS: The mean age was 58 (SD 7) years and the mean baseline body mass index was 34.4 (SD 4.6) kg/m(2). The results of this study showed that ≥5% weight reduction was achieved by 6/33 participants (18%) and by 5/18 adherent participants (28%). A mean weight change of -2.0% (95% CI -2.6 to -1.4) was observed, with changes occurring in the adherent (-3.6%, 95% CI -4.5 to -2.8) but not in the nonadherent (0%, 95% CI -0.6 to 0.7). It was found that each 1% reduction in body weight was associated with a -2.4 mmHg change in systolic (95% CI -3.5 to -1.2) and a -0.8 mmHg change in diastolic blood pressure (95% CI -1.4 to -0.2). Percent weight change was not found to be related to changes in A1C. CONCLUSIONS: In adults with DM2, an Internet-based menu-planning program has the potential to lead to clinically important weight reductions in more than one quarter of those who adhere, with corresponding improvements in blood pressure.

Insulin resistance of protein metabolism in type 2 diabetes and impact on dietary needs: a review.

Evidence shows that the metabolism of protein is altered in type 2 diabetes mellitus and insulin resistance not only applies to glucose and lipid but protein metabolism as well. Population surveys report greater susceptibility to loss of lean tissue and muscle strength with aging in diabetes. Prevention of sarcopenia requires that protein receives more attention in dietary prescriptions. Protein intake of 1-1.2 g/kg of body weight (with weight at a body mass index of 25 kg/m(2))/day may be distributed equally among 3 meals a day, including breakfast, to optimize anabolism. Adopting a dietary pattern that provides a high plant-to-animal ratio and greater food volume favouring consumption of vegetables, legumes, fruits, complemented with fish, low fat dairy and meat (preferably cooked slowly in moisture), soy and nuts may assist with metabolic and weight control. Depending on the magnitude of energy restriction, usual protein intake should be maintained or increased, and the caloric deficit taken from fat and carbohydrate foods. Exercise before protein-rich meals improves skeletal muscle protein anabolism. Because high levels of amino acids lower glucose uptake in individuals without diabetes, the challenge remains to define the optimal protein intake and exercise regimen to protect from losses of muscle mass and strength while maintaining adequate glucose control in type 2 diabetes.

Strategies to optimize participation in diabetes prevention programs following gestational diabetes: a focus group study.

OBJECTIVE: We performed a qualitative study among women within 5 years of Gestational Diabetes (GDM) diagnosis. Our aim was to identify the key elements that would enhance participation in a type 2 diabetes (DM2) prevention program. RESEARCH DESIGN AND METHODS: Potential participants received up to three invitation letters from their GDM physician. Four focus groups were held. Discussants were invited to comment on potential facilitators/barriers to participation and were probed on attitudes towards meal replacement and Internet/social media tools. Recurring themes were identified through qualitative content analysis of discussion transcripts. RESULTS: Among the 1,201 contacted and 79 eligible/interested, 29 women attended a focus group discussion. More than half of discussants were overweight/obese, and less than half were physically active. For DM2 prevention, a strong need for social support to achieve changes in dietary and physical activity habits was expressed. In this regard, face-to-face interactions with peers and professionals were preferred, with adjunctive roles for Internet/social media. Further, direct participation of partners/spouses in a DM2 prevention program was viewed as important to enhance support for behavioural change at home. Discussants highlighted work and child-related responsibilities as potential barriers to participation, and emphasized the importance of childcare support to allow attendance. Meal replacements were viewed with little interest, with concerns that their use would provide a poor example of eating behaviour to children. CONCLUSIONS: Among women within 5 years of a GDM diagnosis who participated in a focus group discussion, participation in a DM2 prevention program would be enhanced by face-to-face interactions with professionals and peers, provision of childcare support, and inclusion of spouses/partners.

Muscle protein anabolism in type 2 diabetes.

PURPOSE OF REVIEW: Protein anabolism is abnormal in human type 2 diabetes (T2DM). We review studies of anabolic stimuli that identify potential causes. If uncorrected, and combined with aging effects, they will compromise muscle function and mass. Knowing causes can guide studies of preventive and treatment measures. RECENT FINDINGS: T2DM accelerates age-related decreases in muscle mass. This could be related to insulin resistance of whole-body protein anabolism demonstrated in hyperglycemic obese men. In contrast, their protein anabolic response to hyperaminoacidemia suggested that ample amino acid administration, especially branched chain amino acids might overcome such insulin resistance. One study of chronic leucine supplementation in elderly T2DM patients did not increase muscle mass. However, they lacked sarcopenia and had adequate dietary protein intake, so may be atypical. Exercise induced similar increases in muscle protein synthesis, mass and strength in healthy and T2DM patients suggesting that physical activity might also overcome insulin resistance of protein anabolism. SUMMARY: Muscle protein anabolism in T2DM is resistant to the action of insulin but perhaps not to amino acid supply or exercise. Whether leucine supplementation improves muscle mass and function in persons with T2DM (especially elderly) with reduced protein intake or muscle mass needs to be determined.

Effects of meal preparation training on body weight, glycemia, and blood pressure: results of a phase 2 trial in type 2 diabetes.

BACKGROUND: Modest reductions in weight and small increases in step- related activity (e.g., walking) can improve glycemic and blood pressure control in type 2 diabetes mellitus (DM2). We examined changes in these parameters following training in time- efficient preparation of balanced, low- energy meals combined with pedometer- based step count monitoring. METHODS: Seventy- two adults with DM2 were enrolled in a 24- week program (i.e., 15 three- hour group sessions). They prepared meals under a chef's supervision, and discussed eating behaviours/nutrition with a registered dietitian. They maintained a record of pedometer- assessed step counts. We evaluated changes from baseline to 24 weeks in terms of weight, step counts, hemoglobin A1c (HbA1c, glycemic control), blood pressure, and eating control ability (Weight Efficacy Lifestyle WEL Questionnaire). 53 participants (73.6%) completed assessments. RESULTS: There were improvements in eating control (11.2 point WEL score change, 95% CI 4.7 to 17.8), step counts (mean change 869 steps/day, 95% CI 198 to 1,540), weight (mean change -2.2%; 95% CI -3.6 to -0.8), and HbA1c (mean change -0.3% HbA1c, 95% CI -0.6 to -0.1), as well as suggestion of systolic blood pressure reduction (mean change -3.5 mm Hg, 95% CI -7.8 to 0.9). Findings were not attributable to medication changes. In linear regression models (adjusted for age, sex, ethnicity, insulin use, season), a -2.5% weight change was associated with a -0.3% HbA1c change (95% CI -0.4 to -0.2) and a -3.5% systolic blood pressure change (95% CI -5.5 to -1.4). CONCLUSIONS: In this 'proof of concept' study, persistence with the program led to improvements in eating and physical activity habits, glycemia reductions, and suggestion of blood pressure lowering effects. The strategy thus merits further study and development to expand the range of options for vascular risk reduction in DM2.

Video game playing is independently associated with blood pressure and lipids in overweight and obese adolescents.

OBJECTIVE: To examine the association between duration and type of screen time (TV, video games, computer time) and blood pressure (BP) and lipids in overweight and obese adolescents. DESIGN: This is a cross-sectional study of 282 overweight or obese adolescents aged 14-18 years (86 males, 196 females) assessed at baseline prior to beginning a lifestyle intervention study for weight control. Sedentary behaviours, defined as hours per day spent watching TV, playing video games, recreational computer use and total screen time were measured by self-report. We examined the associations between sedentary behaviours and BP and lipids using multiple linear regression. RESULTS: Seated video gaming was the only sedentary behaviour associated with elevated BP and lipids before and after adjustment for age, sex, pubertal stage, parental education, body mass index (BMI), caloric intake, percent intake in dietary fat, physical activity (PA) duration, and PA intensity. Specifically, video gaming remained positively associated with systolic BP (adjusted r = 0.13, ß = 1.1, p<0.05) and total cholesterol/HDL ratio (adjusted r = 0.12, ß = 0.14, p<0.05). CONCLUSIONS: Playing video games was the only form of sedentary behaviour that was independently associated with increased BP and lipids. Our findings provide support for reducing time spent playing seated video games as a possible means to promote health and prevent the incidence of cardiovascular disease (CVD) risk factors in this high risk group of overweight and obese adolescents. Future research is needed to first replicate these findings and subsequently aim to elucidate the mechanisms linking seated video gaming and elevated BP and lipids in this high risk population. TRIAL REGISTRATION: Clinicaltrials.gov NCT00195858.

Differences in food intake among obese and nonobese women and men with type 2 diabetes.

OBJECTIVE: Weight reduction is a key goal for the prevention of vascular complications in obese individuals with type 2 diabetes, but a nutritionally balanced intake is also important in this regard. We compared dietary intakes and vitamin supplement use between obese and nonobese women and men with type 2 diabetes to identify gaps in adherence to nutritional management guidelines. METHODS: We analyzed data from a longitudinal study of adults with type 2 diabetes, wherein participants were assessed once per season over 1 year. Dietary data were collected using a validated semiquantitative, self-administered food-frequency questionnaire. Given the absence of seasonal variations in anthropometric variables and dietary intake, data from multiple visits were averaged for each individual. Associations of both intake of fruit and vegetables and nutrients related to cardiovascular disease risk were compared between obese (body mass index ≥ 30 kg/m²) and nonobese individuals through multivariable linear regression with adjustments for age, education, and energy intake. RESULTS: Among the 200 participants (93 women and 107 men), 53% of women and 43% of men were obese. Compared with nonobese women, obese women consumed more saturated fat (mean difference, 1.2% of total energy intake; 95% confidence interval [CI], 3% to 2.2%) and sodium (mean difference, 0.3 g; 95% CI, 0.04 to 0.5 g), and they had a lower intake of fiber (mean difference, -2.7 g; 95% CI, -4.4 to -0.9 g) and magnesium (mean difference, -33.6 mg; 95% CI, -55.2 to -12.0 g). No differences in dietary intake were observed between obese and nonobese men, but the intakes of men overall were similar to those of obese women. Compared with nonobese participants, fewer obese individuals used vitamin/mineral supplements (women: 37% vs 48%, men: 26% vs 38%). CONCLUSIONS: Obese women and both obese and nonobese men appeared to have poorer dietary quality compared with nonobese women. Our findings support the need to emphasize dietary composition in addition to weight control in diabetes.