Substitution of parts of aerobic training by resistance training lowers fasting hyperglycemia in individuals with metabolic syndrome

Acute Statin Withdrawal Does not Interfere With the Improvements of a Session of Exercise in Postprandial Metabolism

BACKGROUND

The risk for atherogenic plaque formation is high after ingestion of meals in individuals with high blood lipid levels (ie, dyslipidemia). Statins and exercise reduce the rise of blood triglyceride concentrations after a meal, but the effect of their combination is unclear.

METHODS

In a randomized crossover design, 11 individuals with dyslipidemia and metabolic syndrome treated with statins underwent a mixed-meal (970 ± 111 kcal, 24% fat, and 34% carbohydrate) tolerance test. Plasma lipid concentrations, fat oxidation, glucose, and glycerol kinetics were monitored immediately prior and during the meal test. Trials were conducted with participants under their habitual statin treatment and 96 hours after blinded statin withdrawal. Trials were duplicated after a prolonged bout of low-intensity exercise (75 minutes at 53 ± 4% maximal oxygen consumption) to study the interactions between exercise and statins.

RESULTS

Statins reduced postprandial plasma triglycerides from 3.03 ± 0.85 to 2.52 ± 0.86 mmol·L-1 (17%; P = .015) and plasma glycerol concentrations (ie, surrogate of whole-body lipolysis) without reducing plasma free fatty acid concentration or fat oxidation. Prior exercise increased postprandial plasma glycerol levels (P = .029) and fat oxidation rates (P = .024). Exercise decreased postprandial plasma insulin levels (241 ± 116 vs 301 ± 172 ρmol·L-1; P = .026) but not enough to increase insulin sensitivity (P = .614). Neither statins nor exercise affected plasma glucose appearance rates from exogenous or endogenous sources.

CONCLUSIONS

In dyslipidemic individuals, statins reduce blood triglyceride concentrations after a meal, but without limiting fat oxidation. Statins do not interfere with exercise lowering the postprandial insulin that likely promotes fat oxidation. Last, statins do not restrict the rates of plasma incorporation or oxidation of the ingested glucose.

Insulin resistance, lipids and body composition in patients with coronary artery disease after combined aerobic training and resistance training: a randomised, controlled trial

BACKGROUND

The effect of resistance training (RT) in cardiac rehabilitation (CR) on insulin resistance remains elusive. We examined whether the addition of high-load (HL) or low loads (LL) RT has any effect on the levels of insulin resistance and lipids versus aerobic training (AT) alone in patients with coronary artery disease (CAD).

METHODS

Seventy-nine CAD patients were randomised to HL-RT [70-80% of one repetition maximum (1-RM)] and AT, LL-RT (35-40% of 1-RM) and AT or AT (50-80% of maximal power output), and 59 patients [75% males, 15% diabetics, age: 61 (8) years, left ventricular ejection fraction: 53 (9) %] completed the study. Plasma levels of glucose, insulin, blood lipids [total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL)] cholesterol and body composition were measured at baseline and post-training (36 training sessions).

RESULTS

Training intervention had only time effect on lean mass (p = 0.002), total and LDL cholesterol levels (both p < 0.001), and no effects on levels of glucose and insulin resistance (homeostatic assessment 2-insulin resistance). Total and LDL cholesterols levels decreased following AT [mean difference (95% confidence interval); total cholesterol: - 0.4 mmol/l (- 0.7 mmol/l, - 0.1 mmol/l), p = 0.013; LDL: - 0.4 mmol/l (- 0.7 mmol/l, - 0.1 mmol/l), p = 0.006] and HL-RT [total cholesterol: - 0.5 mmol/l (- 0.8 mmol/l, - 0.2 mmol/l), p = 0.002; LDL: - 0.5 mol/l (- 0.7 mmol/l, - 0.2 mmol/l), p = 0.002]. No associations were observed between post-training change in body composition and post-training change in blood biomarkers.

CONCLUSIONS

RT when combined with AT had no additional effect beyond AT alone on fasting glucose metabolism, blood lipids and body composition in patients with CAD. Trial registration number NCT04638764.

Effect of Yearly Exercise on Medication Expense and Benefit-Cost Ratio in Individuals with Metabolic Syndrome: A Randomized Clinical Trial

INTRODUCTION

Lifestyle modification through incorporation of exercise training could improve metabolic syndrome (MetS) clinical components (hypertension, dyslipidemia, hyperglycemia, and visceral abdominal obesity). We aimed to assess if long-term exercise training could restrain the increased pharmacological cost of the clinical management of the MetS.

METHODS

Medicine cost during a 5-yr-long randomized controlled exercise intervention trial was analyzed. After a per-protocol analysis, a group of 64 individuals 53 ± 2 yr old, with overweight (body mass index, 33.4 ± 0.9 kg·m -2 ) and MetS (3.6 ± 0.2 factors) were randomized to a training (4 months·yr -1 for 5 yr; EXERCISE, n = 25) or to a control group (CONTROL, n = 26). Subjects were studied on three occasions during the 5-yr follow-up. Participants continued their routine medication managed by their general practitioner. The main outcome is the 5-yr evolution of medication cost to treat MetS (hyperglycemia, hypertension, and hyperlipidemia). A secondary outcome is the benefit-cost ratio of the exercise intervention.

RESULTS

In CONTROL, medicine cost increased 160% from baseline ( P < 0.001), whereas in EXERCISE, it remained unchanged (33%; P = 0.25). After the 5-yr follow-up, medicine use was 60% and medicine cost 74% higher in CONTROL than EXERCISE ( P < 0.05 in both cases). However, MetS z score was similarly reduced over time in both groups ( P = 0.244 for group-time interaction). The number of prescribed medications increased after 5 yr in CONTROL (89%; P < 0.001), whereas it remained stable with yearly training (17%; P = 0.72 in EXERCISE). Ten-year atherosclerotic cardiovascular disease risk estimation increased only in CONTROL (15%; P = 0.05 for group-time interaction). The benefit in medicine savings (€153 per year and patient) triplicated the estimated cost (€50.8 per year and patient) of the exercise intervention.

CONCLUSIONS

A 5-yr-long supervised exercise training program in middle-age individuals with MetS prevents the need for increasing medicine use. The savings in pharmacological therapy outweighs the estimated costs of implementing the exercise program.

Chronic Statin Treatment Does Not Impair Exercise Lipolysis or Fat Oxidation in Exercise-Trained Individuals With Obesity and Dyslipidemia

OBJECTIVE

To determine whether statin medication in individuals with obesity, dyslipidemia, and metabolic syndrome affects their capacity to mobilize and oxidize fat during exercise.

METHODS

Twelve individuals with metabolic syndrome pedaled during 75 min at 54 ± 13% V˙O2max (5.7 ± 0.5 metabolic equivalents) while taking statins (STATs) or after 96-hr statin withdrawal (PLAC) in a randomized double-blind fashion.

RESULTS

At rest, PLAC increased low-density lipoprotein cholesterol (i.e., STAT 2.55 ± 0.96 vs. PLAC 3.16 ± 0.76 mmol/L; p = .004) and total cholesterol blood levels (i.e., STAT 4.39 ± 1.16 vs. PLAC 4.98 ± 0.97 mmol/L; p = .008). At rest, fat oxidation (0.99 ± 0.34 vs. 0.76 ± 0.37 μmol·kg-1·min-1 for STAT vs. PLAC; p = .068) and the rates of plasma appearance of glucose and glycerol (i.e., Ra glucose-glycerol) were not affected by PLAC. After 70 min of exercise, fat oxidation was similar between trials (2.94 ± 1.56 vs. 3.06 ± 1.94 μmol·kg-1·min-1, STA vs. PLAC; p = .875). PLAC did not alter the rates of disappearance of glucose in plasma during exercise (i.e., 23.9 ± 6.9 vs. 24.5 ± 8.2 μmol·kg-1·min-1 for STAT vs. PLAC; p = .611) or the rate of plasma appearance of glycerol (i.e., 8.5 ± 1.9 vs. 7.9 ± 1.8 μmol·kg-1·min-1 for STAT vs. PLAC; p = .262).

CONCLUSIONS

In patients with obesity, dyslipidemia, and metabolic syndrome, statins do not compromise their ability to mobilize and oxidize fat at rest or during prolonged, moderately intense exercise (i.e., equivalent to brisk walking). In these patients, the combination of statins and exercise could help to better manage their dyslipidemia.

One Bout of Resistance Training Does Not Enhance Metformin Actions in Prediabetic and Diabetic Individuals

PURPOSE

This study aimed to determine the separated and combined effects of metformin and resistance exercise on glycemic control, insulin sensitivity, and insulin-like growth factor 1 (IGF-1) in overweight/obese individuals with prediabetes and type 2 diabetes mellitus.

METHODS

Fourteen adults with a body mass index of 32.1 ± 4.1 kg·m-2, insulin resistance (HOMA-2 1.6 ± 0.6), and poor glycemic control (glycated hemoglobin, 6.9% ± 0.9%; 51.9 ± 10.7 mmol·mol-1) while taking metformin (1561 ± 470 g·d-1) were recruited. Participants underwent four 72-h long experimental trials in a randomized counterbalanced order, either 1) taking metformin (MET), 2) replacing metformin by placebo pills (PLAC), 3) taking placebo and undergoing a resistance training bout (RT + PLAC), and 4) taking metformin and undergoing the same RT bout (RT + MET). Interstitial fluid glucose concentration was frequently sampled to obtain 72-h glucose area under the curve (GAUC) and the percentage hyperglycemic glucose readings (>180 mg·dL-1; GPEAKS). Insulin sensitivity (i.e., HOMA-2) and IGF-1 were also assessed.

RESULTS

HOMA-2 was not affected by treatments. GAUC and GPEAKS were similarly reduced below PLAC during RT + MET and MET (all P < 0.05). In contrast, RT + PLAC did not affect glucose concentration. Metformin decreased serum IGF-1 concentrations (P = 0.006), and RT did not reverse this reduction.

CONCLUSIONS

A bout of full-body RT does not interfere or aid on metformin's blood glucose-lowering actions in individuals with prediabetes and type 2 diabetes mellitus.

Effects of metabolic syndrome on fuel utilization during exercise on middle-aged moderately trained individuals

People with the metabolic syndrome (MetS) may have blunted exercise stimulation of metabolism explaining their resistance to lower blood glucose and triglycerides with exercise training. Glycerol and glucose rate of appearance (Ra) in plasma and substrate oxidation were determined at rest and during cycle ergometer exercise at three increasing intensities (55, 80 and 95% of maximal heart rate) in 9 middle-aged (61±7 yr) individuals with MetS. Data were compared to 8 healthy-younger (29±10 yr) individuals matched for habitual exercise training and fat free mass (Healthy-young). At rest, fasting plasma triglycerides (TG), blood glucose and insulin were higher in MetS than in Healthy-young (38%, 42% and 85%, respectively; all p<0.05). At rest, and during low intensity exercise (32-43% VO2MAX), plasma glycerol Ra (index of whole-body lipolysis) and glucose Ra and Rd (index of glucose appearance and disposal) were similar in MetS and Healthy-young. Fat oxidation peaked at low intensity exercise similarly in MetS and Healthy-young (0.273±0.082 vs 0.272±0.078 g·min-1, respectively; p = 0.961). Ra glycerol increased with exercise intensity but was lower in MetS at moderate and high exercise intensities (i.e., 60-100% VO2MAX; p<0.05). Metabolic clearance rate of glucose at high intensity (85-100% VO2MAX) was lower in MetS compared to Healthy-young (p = 0.029). The MetS that develops in middle adulthood, reduces exercise lipolysis and plasma glucose clearance at high exercise intensities, but does not blunt fat or carbohydrate metabolism at low exercise intensity.

Exercise Reduces Medication for Metabolic Syndrome Management: A 5-Year Follow-up Study

PURPOSE

This study aimed to determine the effects of a 5-yr exercise intervention on metabolic syndrome (MetS) and health-related variables and medication use for MetS management.

METHODS

Participants were randomly assigned to an exercise intervention (n = 25, 54 ± 2 yr, 20% women) or control group (n = 26, 54 ± 2 yr, 38% women). The intervention lasted 4 months per year and consisted of high-intensity interval training on a cycloergometer thrice a week. Outcomes were MetS z-score and medication use score, MetS-related variables (including blood pressure, blood glucose homeostasis, and lipid profile), and cardiorespiratory fitness (CRF, as determined by maximal oxygen uptake).

RESULTS

MetS z-score was similarly reduced over time in both groups (P = 0.244 for group-time interaction). A quasi-significant and significant group-time interaction was found for MetS number of factors (P = 0.004) and CRF (P < 0.001), respectively. Thus, MetS factors tended to decrease over time only in the exercise group with no change in the control group, whereas CRF increased from baseline to 5-yr assessment in the exercise group (by 1.1 MET, P < 0.001) but decreased in the control group (-0.5 MET, P = 0.025). Medicine use score increased twofold from baseline to 5-yr follow-up in the control group (P < 0.001) but did not significantly change (10%, P = 0.52) in the exercise group (P < 0.001 for group-time interaction). The proportion of medicated patients who had to increase antihypertensive (P < 0.001), glucose-lowering (P = 0.036), or total medication (P < 0.0001) over the 5-yr period was lower in the exercise than that in the control group.

CONCLUSIONS

Exercise training can attenuate the increase in medication that would be otherwise required to manage MetS over a 5-yr period.

Considerations for Maximizing the Exercise "Drug" to Combat Insulin Resistance: Role of Nutrition, Sleep, and Alcohol

Insulin resistance is a key etiological factor in promoting not only type 2 diabetes mellitus but also cardiovascular disease (CVD). Exercise is a first-line therapy for combating chronic disease by improving insulin action through, in part, reducing hepatic glucose production and lipolysis as well as increasing skeletal muscle glucose uptake and vasodilation. Just like a pharmaceutical agent, exercise can be viewed as a "drug" such that identifying an optimal prescription requires a determination of mode, intensity, and timing as well as consideration of how much exercise is done relative to sitting for prolonged periods (e.g., desk job at work). Furthermore, proximal nutrition (nutrient timing, carbohydrate intake, etc.), sleep (or lack thereof), as well as alcohol consumption are likely important considerations for enhancing adaptations to exercise. Thus, identifying the maximal exercise "drug" for reducing insulin resistance will require a multi-health behavior approach to optimize type 2 diabetes and CVD care.

Concurrent endurance and resistance training enhances muscular adaptations in individuals with metabolic syndrome

The purpose of the study was to determine if concurrent training (endurance and resistance in a single session) elicits leg muscular adaptations beyond the ones obtained by endurance training alone in sedentary individuals with metabolic syndrome (MetS). Sixty-six MetS individuals (37% women, age 56 ± 7 years, BMI 32 ± 5 kg m^-2 and 3.8 ± 0.8 MetS factors) were randomized to undergo one of the following 16-week isocaloric exercise programs: (i) 4 + 1 bouts of 4 min at 90% of HR_MAX of intense aerobic cycling (IAC + IAC group; n = 33), (ii) 4 IAC bouts followed by 3 sets of 12 repetitions of 3 lower-limb free-weight exercises (IAC + RT group; n = 33). We measured the effects of training on maximal cycling power, leg press maximum strength (1RM), countermovement jump height (CMJ), and mean propulsive velocity (MPV) at workloads ranging from 10% to 100% of baseline 1RM leg press. After intervention, MetS components (Z-score) improved similarly in both groups (p = 0.002). Likewise, maximal cycling power during a ramp test improved similarly in both groups (time effect p < 0.001). However, leg press 1RM improved more in IAC + RT than in IAC + IAC (47 ± 5 vs 13 ± 5 kg, respectively, interaction p < 0.001). CMJ only improved with IAC + RT (0.8 ± 0.2 cm, p = 0.001). Leg press MPV at heavy loads (ie, 80%-100% 1RM) improved more with concurrent training (0.12 ± 0.01 vs 0.06 ± 0.02 m s^-1 , interaction p = 0.013). In conclusion, in unconditioned MetS individuals, intense aerobic cycling alone improves leg muscle performance. However, substituting 20% of intense aerobic cycling by resistance training further improves 1RM leg press, MPV at high loads, and jumping ability while providing similar improvement in MetS components.