Tasuku Terada

Feasibility and preliminary efficacy of high intensity interval training in type 2 diabetes.

AIMS To compare the feasibility of high intensity interval exercise (HI-IE) versus moderate intensity continuous exercise (MI-CE) in patients with type 2 diabetes (T2D), and to investigate the preliminary efficacy of HI-IE and MI-CE for improving glycated hemoglobin A1c (HbA1c) and body composition. METHODS Individuals with T2D were recruited and randomly assigned to HI-IE and MI-CE. Exercise training was performed 5 days per week for 12 weeks. Recruitment, retention, adherence, feeling states and self-efficacy were analyzed for feasibility. Changes in HbA1c and percent body fat from baseline were investigated at 12 weeks to determine the preliminary efficacy. RESULTS Of 126 participants showing interest to join the study, 15 individuals were randomized and completed the program. No participants dropped out from the study after enrollment. Adherence rates were high and did not differ between HI-IE and MI-CE (p>0.05; >97.2% of the eligible exercise sessions for both groups). Feeling states and self-efficacy did not differ between the groups. Percent trunk fat decreased in both HI-IE and MI-CE (p=0.007 and 0.085, respectively). Total percent body fat, percent leg fat, and subcutaneous fat width were significantly reduced in both groups (p<0.05), whereas HbA1c did not change from baseline (p>0.05). The degree of improvement was similar between the interventions (p>0.05). CONCLUSION In individuals with T2D, implementing a 12-week structured HI-IE training can be as feasible as MI-CE training. Both interventions are equally effective in lowering total body fat but have little impact on HbA1c in relatively well controlled participants with T2D.

Exercise lowers postprandial glucose but not fasting glucose in type 2 diabetes: a meta-analysis of studies using continuous glucose monitoring

Exercise has repeatedly been shown to improve glycemic control as assessed by glycated hemoglobin. However, changes in glycated hemoglobin do not provide information regarding which aspects of glycemic control have been altered. The purpose of this systematic review was to examine the effect of exercise as assessed by continuous glucose monitoring systems (CGMS) in type 2 diabetes.

Exploring the Variability in Acute Glycemic Responses to Exercise in Type 2 Diabetes

Aim. To explore the factors associated with exercise-induced acute capillary glucose (CapBG) changes in individuals with type 2 diabetes (T2D). Methods. Fifteen individuals with T2D were randomly assigned to energy-matched high intensity interval exercise (HI-IE) and moderate intensity continuous exercise (MI-CE) interventions and performed a designated exercise protocol 5 days per week for 12 weeks. The duration of exercise progressed from 30 to 60 minutes. CapBG was measured immediately before and after each exercise session. Timing of food and antihyperglycemic medication intake prior to exercise was recorded. Results. Overall, the mean CapBG was lowered by 1.9 mmol/L (P < 0.001) with the change ranging from −8.9 to +2.7 mmol/L. Preexercise CapBG (44%; P < 0.001), medication (5%; P < 0.001), food intake (4%; P = 0.043), exercise duration (5%; P < 0.001), and exercise intensity (1%; P = 0.007) were all associated with CapBG changes, explaining 59% of the variability. Conclusion. The greater reduction in CapBG seen in individuals with higher preexercise CapBG may suggest the importance of exercise in the population with elevated glycemia. Lower blood glucose can be achieved with moderate intensity exercise, but prolonging exercise duration and/or including brief bouts of intense exercise accentuate the reduction, which can further be magnified by performing exercise after meals and antihyperglycemic medication. This trial is registered with ClinicalTrial.gov NCT01144078.

Targeting specific interstitial glycemic parameters with high-intensity interval exercise and fasted-state exercise in type 2 diabetes.

AIMS To compare the acute glycemic responses to a bout of high-intensity interval exercise (HIIE) and energy-matched moderate-intensity continuous exercise (MICE) performed under fasted and postprandial conditions. METHODS A randomized, controlled, crossover design was used. Ten individuals with type 2 diabetes were each tested in five experimental conditions after an overnight fast: 1) fasted-state HIIE (HIIEfast); 2) post-breakfast HIIE (HIIEfed); 3) fasted-state MICE (MICEfast); 4) post-breakfast MICE (MICEfed); and 5) no exercise (control). MICE was performed at workload corresponding to 55% of V.V̇O2peak, whereas HIIE was composed of repetitions of three minutes at workload corresponding to 40% followed by one minute at workload corresponding to 100% V.V̇̇O2peak. Interstitial glucose was monitored by continuous glucose monitoring over 24h under standardized diet and medication. RESULTS Fasted-state exercise attenuated postprandial glycemic increments (p<0.05) to a greater extent than post-breakfast exercise did. HIIE reduced nocturnal and fasting glycemia on the day following exercise more than MICE did (main effect: both p<0.05). Compared to the control condition, HIIEfast lowered most interstitial glycemic parameters, i.e., 24-h mean glucose (-1.5mmol·l(-1); p<0.05), fasting glucose (-1.0mmol·l(-1); p<0.05), overall postprandial glycemic increment (-257mmol·360min·l(-1); p<0.05), glycemic variability (-1.79mmol·l(-1); p<0.05), and time spent in hyperglycemia (-283min; p<0.05). CONCLUSION This study showed that HIIE is more effective than MICE in lowering nocturnal/fasting glycemia. Exercise performed in the fasted state reduces postprandial glycemic increments to a greater extent than post-breakfast exercise does. Performing HIIE under fasted condition may be most advantageous as it lowered most aspects of glycemia.

The Effect of Exercise with or Without Metformin on Glucose Profiles in Type 2 Diabetes: A Pilot Study.

The studys goals were 1) to confirm the previously observed increase in postprandial glucose levels immediately after exercise in people with type 2 diabetes who are being treated with metformin; 2) to determine how long the increased glucose persists; 3) to examine the effect of skipping a dose of metformin before or after exercise. We recruited 10 participants with type 2 diabetes who were taking metformin. They completed 4 experimental conditions in random order: 1) morning and evening metformin doses, without exercise (M-M); 2) morning and evening metformin doses, with exercise (M-Ex-M); 3) exercise with evening metformin dose only (Ex-M); and 4) morning metformin dose only, with exercise (M-Ex). Exercise consisted of walking for 50 minutes at a moderate intensity at 11 am on the first day of each condition. Glucose was measured for 72 hours using continuous glucose monitoring systems. Standardized breakfasts were provided for 3 days in each condition, and standardized lunches and dinners were provided on the first day. Compared to M-M, M-Ex-M increased the average 2-hour incremental postprandial area under the curve following the 5 standardized meals (p<0.01) but did not affect daily mean glucose or fasting glucose concentrations. M-Ex (p<0.05), but not Ex-M (p=0.08) increased mean glucose concentrations compared to M-Ex-M on day 1. There were no differences among the 3 exercise conditions for fasting or postprandial glucose concentrations. The addition of a bout of exercise to metformin led to an increase in postprandial glucose levels without affecting mean glucose concentrations. Removing a metformin dose before or after exercise did not attenuate this negative effect.

Severe Obesity Is Associated With Increased Risk of Early Complications and Extended Length of Stay Following Coronary Artery Bypass Grafting Surgery

Background Better understanding of the relationship between obesity and postsurgical adverse outcomes is needed to provide quality and efficient care. We examined the relationship of obesity with the incidence of early adverse outcomes and in‐hospital length of stay following coronary artery bypass grafting surgery. Methods and Results We analyzed data from 7560 patients who underwent coronary artery bypass grafting. Using body mass index (BMI; in kg/m2) of 18.5 to 24.9 as a reference, the associations of 4 BMI categories (25.0–29.9, 30.0–34.9, 35.0–39.9, and ≥40.0) with rates of operative mortality, overall early complications, subgroups of early complications (ie, infection, renal and pulmonary complications), and length of stay were assessed while adjusting for clinical covariates. There was no difference in operative mortality; however, higher risks of overall complications were observed for patients with BMI 35.0 to 39.9 (adjusted odds ratio 1.35, 95% CI 1.11–1.63) and ≥40.0 (adjusted odds ratio 1.56, 95% CI 1.21–2.01). Subgroup analyses identified obesity as an independent risk factor for infection (BMI 30.0–34.9: adjusted odds ratio 1.60, 95% CI 1.24–2.05; BMI 35.0–39.9: adjusted odds ratio 2.34, 95% CI 1.73–3.17; BMI ≥40.0: adjusted odds ratio 3.29, 95% CI 2.30–4.71). Median length of stay was longer with BMI ≥40.0 than with BMI 18.5 to 24.9 (median 7.0 days [interquartile range 5 to 10] versus 6.0 days [interquartile range 5 to 9], P=0.026). Conclusions BMI ≥40.0 was an independent risk factor for longer length of stay, and infection was a potentially modifiable risk factor. Greater perioperative attention and intervention to control the risks associated with infection and length of stay in patients with BMI ≥40.0 may improve patient care quality and efficiency.

Cardiometabolic risk factors in type 2 diabetes with high fat and low muscle mass: At baseline and in response to exercise

To examine the interplay between high fat and low muscle mass on cardiometabolic risk factors at baseline and in response to exercise in type 2 diabetes.

Body Mass Index Is Associated With Differential Rates of Coronary Revascularization After Cardiac Catheterization

BACKGROUND The association of obesity with coronary revascularization procedures is not clear. We examined rates of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) associated with obesity while accounting for the severity of coronary disease and diabetes status. METHODS Patients who underwent cardiac catheterization were stratified according to coronary anatomy risks and diabetes status. Within each stratum, using normal body mass index (BMI) (18.5-24.9 kg/m2) as a reference, the associations of overweight (25.0-29.9 kg/m2), obese class I (30.0-34.9 kg/m2), obese class II (35.0-39.9 kg/m2), and obese class III (≥ 40.0 kg/m2) with the likelihood of receiving CABG and PCI were assessed while adjusting for clinical covariates. RESULTS Of 56,722 patients analyzed, overall use of revascularization was higher in the overweight, obese class I, and obese class II groups (overweight: adjusted hazard ratio [aHR], 1.10; 95% confidence interval [CI], 1.06-1.13; obese class I: aHR, 1.08; 95% CI, 1.05-1.12; obese class II: aHR,1.05; 95% CI, 1.01-1.10), whereas it was lower in the obese class III group (aHR, 0.91; 95% CI, 0.85-0.97) compared with normal BMI. In the subgroup with high-risk coronary anatomy and diabetes, all obese classes had higher rates of PCI (obese class I: aHR,1.24; 95% CI, 1.08-1.42; obese class II: aHR,1.27; 95% CI, 1.07-1.49, obese class III: aHR,1.37; 95% CI, 1.12-1.67) than the normal BMI group. CONCLUSIONS Our results showed that BMI is associated with differential rates of coronary revascularization. In patients with high-risk coronary anatomy and diabetes, clinical appropriateness of higher rates of PCI associated with obesity warrants further investigation.

Reply to Elsamma Chacko: "Timing, intensity and frequency of exercise for glucose control".

We thank Dr. Chacko [1] for her interest in our article and her constructive discussion. We agree that the timing of exercise, in relation to meals for example, may influence the effect of exercise on glycemic control or insulin sensitivity. Unfortunately, we were unable to examine this issue in our meta-analyses since none of the eight included studies had attempted to control exercise timing [2]. We did, however, indirectly examine this issue in a secondary publication [3] from one of the trials included in our metaanalysis. In this study, participants were allowed to exercise at a time of their convenience, but the interval between the individual exercise bout and the most recent meal intake was noted. We observed greater reductions in glucose when exercise was performed within 2 h after a meal. This is perhaps not surprising as one may expect glucose to have declined even in the absence of exercise (i.e. peak glucose concentrations are often obtained within 2 h of a meal). In an attempt to more clearly examine the effect of exercise intensity as well as meal timing on glycemia, we recently conducted a study comparing five conditions: (1) fasted-state high-intensity interval exercise (HIIEfast); (2) post-breakfast HIIE (HIIEfed); (3) fasted-state moderateintensity continuous exercise (MICEfast); (4) post-breakfast MICE (MICEfed) and (5) no exercise (control) [4]. While there were some small differences among the four exercise conditions, the main finding was that all exercise conditions led to improvements in 24 h glucose profiles compared to the control condition [4]. As argued by Dr. Chacko, even though exercise timing can affect acute glycemic responses, there is a particular need for longerterm studies on outcomes such as HbA1c. Dr. Chacko also mentions ‘‘I cannot think of any reason why exercise timing is left out from the methods section of studies exploring glycemic response to exercise’’ [1]. We would suggest that glycemic responses often represent only one of several outcomes of interest in exercise studies. There are many other benefits of exercise (e.g. changes in fitness or quality of life) which may not be as profoundly affected by exercise timing. Furthermore, there is a desire to minimize barriers to exercise when designing trials. Adding further restrictions regarding when exercise should be performed would likely accentuate challenges surrounding recruitment of participants and adherence to exercise interventions. Another interesting point by Dr. Chacko was concerning the issue of exercise frequency. She noted that in the studies from our review, the higher intensity exercise interventions with lower exercise frequency (i.e. three times per week) had greater improvement in HbA1c compared to those with higher exercise frequency (i.e. five times per week). While this is an interesting observation, we believe caution should be applied to this interpretation from six studies with small sample sizes. Recent metaregression analyses by Umpierre et al. (based on a much greater number of studies) suggested that greater exercise frequency is one of the strongest predictors of improvements in HbA1c [5]. Furthermore, participants in the studies from our meta-analyses were not randomly assigned to lower versus higher frequency, so other Managed by Antonio Secchi.

Differences in Short‐ and Long‐Term Mortality Associated With BMI Following Coronary Revascularization

Background The association between obesity and mortality risks following coronary revascularization is not clear. We examined the associations of BMI (kg/m2) with short‐, intermediate‐, and long‐term mortality following coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) in patients with different coronary anatomy risks and diabetes mellitus status. Methods and Results Data from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) registry were analyzed. Using normal BMI (18.5–24.9) as a reference, multivariable‐adjusted hazard ratios for all‐cause mortality within 6 months, 1 year, 5 years, and 10 years were individually calculated for CABG and PCI with 4 prespecified BMI categories: overweight (25.0–29.9), obese class I (30.0–34.9), obese class II (35.0–39.9), and obese class III (≥40.0). The analyses were repeated after stratifying for coronary risks and diabetes mellitus status. The cohorts included 7560 and 30 258 patients for CABG and PCI, respectively. Following PCI, overall mortality was lower in patients with overweight and obese class I compared to those with normal BMI; however, 5‐ and 10‐year mortality rates were significantly higher in patients with obese class III with high‐risk coronary anatomy, which was primarily driven by higher mortality rates in patients without diabetes mellitus (5‐year adjusted hazard ratio, 1.78 [95% CI, 1.11–2.85] and 10‐year adjusted hazard ratio, 1.57 [95% CI, 1.02–2.43]). Following CABG, overweight was associated with lower mortality risks compared with normal BMI. Conclusions Overweight was associated with lower mortality following CABG and PCI. Greater long‐term mortality in patients with obese class III following PCI, especially in those with high‐risk coronary anatomy without diabetes mellitus, warrants further investigation.