Exercise Periodization over the Year Improves Metabolic Syndrome and Medication Use

Pulmonary function, genetic predisposition, and the risk of cirrhosis: A prospective cohort study

OBJECTIVE

Pulmonary function is associated with the development of chronic liver disease. However, evidence of the association between pulmonary function and cirrhosis risk is still lacking. This study aimed to investigate the longitudinal associations of pulmonary function with the development of cirrhosis, and to explore whether genetic predisposition to cirrhosis could modify these associations.

METHODS

Of 294,835 participants free of cirrhosis and had undergone spirometry at baseline from the UK Biobank were included. Cirrhosis diagnoses were ascertained through linked hospital records and death registries. Cox proportional hazard models were employed to investigate the longitudinal associations between pulmonary function, genetic predisposition, and cirrhosis risk.

RESULTS

During a median follow-up of 12.0 years, 2598 incident cirrhosis cases were documented. Compared to individuals with normal spirometry findings, those with preserved ratio impaired spirometry (PRISm) findings (hazard ratio [HR] and 95% confidence interval [CI]: 1.32 [1.18, 1.48]) and airflow obstruction (HR [95%CI]: 1.19 [1.07, 1.31]) had a higher risk of developing cirrhosis after adjustments. These associations were consistent across all categories of genetic predisposition, with no observed modifying effect of genetic predisposition. In joint exposure analyses, the highest risk was observed in individuals with both a high genetic predisposition for cirrhosis and PRISm findings (HR [95% CI]: 1.74 [1.45, 2.08]).

CONCLUSIONS

Our findings indicate that worse pulmonary function is a significant risk factor of cirrhosis, irrespective of genetic predisposition. Early identification and appropriate intervention for pulmonary function may lead to more effective healthcare resource utilization and reduce the burden associated with cirrhosis.

Metabolic Syndrome, Modifiable Lifestyle Factors, and Sleep-Disordered Breathing: The Hispanic Community Health Study

BACKGROUND

US Hispanics/Latinos are disproportionately susceptible to metabolic syndrome (MetS), attributed in part to systemic inequities related to health and lifestyle factors such as low physical activity (PA) levels, diet quality, alcohol use, tobacco use, and sleep disorder. Gender and heritage group differences are vastly understudied and need to be examined in this heterogeneous population.

PURPOSE

To examine the relationships between select health and lifestyle factors and MetS among Hispanic gender and heritage subgroups (Hypothesis 1) and determine whether gender and heritage moderate those relationships (Hypothesis 2).

METHODS

Participants included 14,155 Hispanic Americans aged 18-76 (59% female, mean age 45.92 ± 13.97) from seven heritage subgroups. This secondary analysis of cross-sectional data from the observational Hispanic Community Health Study/Study of Latinos (HCHS/SOL) dataset used hierarchical multinomial logistic regression to test Hypothesis 1; the dependent variable, MetS, included three categories delineating absence of MetS and presence of MetS with or without related medication use. Hayes' PROCESS macro tested Hypothesis 2.

RESULTS

Low PA and sleep-disordered breathing (SDB) each had significant (p < .001) predictive value of MetS group membership, whereas both low and high alcohol use (p < .001) were associated with decreased MetS risk. Cigarette pack-years were not significantly associated with MetS outcomes. Gender moderated the association between MetS and alcohol use (p < .001), cigarette pack-years (p < .001), and SDB (p < .001) such that the effects on MetS were higher in females than males. The association between MetS and diet quality (p < .001) was stronger among males than in females.

CONCLUSIONS

Gender and heritage differences were prominent among study variables.

Effects of statins on fat oxidation improvements after aerobic exercise training

BACKGROUND

Statin blunts cardiorespiratory fitness improvements after exercise training and may affect fat oxidation adaptations to training.

METHODS

One hundred and six metabolic syndrome individuals either chronically medicated with statins (i.e., STATIN group; n = 46) or statin naïve (i.e., CONTROL group; n = 60) completed a 16-week supervised high-intensity interval training (HIIT) program. Maximal rates of oxygen consumption (V̇O2MAX), fat oxidation (FOMAX), and the shape of the workload-fat oxidation curve were assessed before and 48 h after training in an overnight fasted state.

RESULTS

Starting from a similar value at baseline, both groups increased V̇O2MAX after training, but the increase was larger in the CONTROL than in the STATIN group (19.4% vs. 12.6%; P = 0.013). Before training, FOMAX in the STATIN group was lower (0.19 ± 0.08 vs. 0.23 ± 0.07 g·min-1; P = 0.023) and took place at a lower workload (33 ± 21 vs. 37 ± 19 W; P = 0.015) than in CONTROL. After training, FOMAX improved similarly in both groups (0.06 ± 0.08; 95% CI, 0.03 to 0.08 g·min-1 and 0.05 ± 0.09; 95% CI, 0.03 to 0.07 g·min-1, for STATIN and CONTROL respectively; P < 0.001). Still, after training, FOMAX occurred at a 28% lower workload in the STATIN group (38 ± 26 vs. 53 ± 32 W, P = 0.048).V̇O2 -workload slope decreased after training in both groups (both P < 0.001) along with reductions in the respiratory exchange ratio - workload slope. Fat oxidation increased at all workloads after training regardless of the use of statins.

CONCLUSION

Long-term statin treatment is associated with blunted exercise fat oxidation before exercise training. However, statin use does not blunt the improvements in exercise fat oxidation (FOMAX) derived from intense aerobic exercise training. This finding should encourage statin users to exercise-train to benefit from increased fat oxidation once their fitness level improves.

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.

Exercise Training Adaptations in Metabolic Syndrome Individuals on Chronic Statin Treatment

BACKGROUND

Statins reduce atherogenic dyslipidemia and cardiovascular disease (CVD) risk in metabolic syndrome (MetS) individuals. Exercise training could also contribute to reduce CVD by improving cardiorespiratory fitness and fat oxidation. However, statin use could interfere with training adaptations.

METHODS

A total of 106 MetS individuals were divided into statin users (statin group, n = 46) and statin-naïve (control group, n = 60). Groups were matched by age, weight, and MetS components. Subjects completed 16 weeks of high intensity interval training (HIIT). Before and after HIIT, muscle biopsies were collected to assess mitochondrial content (citrate synthase [CS] activity) and the activity of the rate limiting β-oxidation enzyme (3-hydroxyacyl-CoA-dehydrogenase [HAD]). Fasting plasma glucose, insulin, TG, HDL-c, and LDL-c concentrations were measured. Exercise maximal fat oxidation (FOMAX) and oxygen uptake (VO2PEAK) were determined.

RESULTS

Training improved MetS similarly in both groups (MetS z-score -0.26 ± 0.38 vs. -0.22 ± 0.31; P < 0.001 for time and P = 0.60 for time x group). Before training, the statin group had reduced muscle HAD activity and whole body FOMAX compared to the control group. However, 16 weeks of HIIT increased HAD and FOMAX in both groups (P < 0.03, time-effect). The statin group did not prevent the increases in CS with HIIT observed in the control group (38% vs 64%, respectively; P < 0.001, time-effect). Conversely, with training VO2PEAK improved less in the statin than in the control group (12% vs. 19%, respectively; P = 0.013, time × group effect).

CONCLUSION

Chronic statin use in MetS does not interfere with exercise training improvements in MetS components, FOMAX, or mitochondrial muscle enzymes (ie, CS and HAD). However, the statin group attenuated the improvements in VO2PEAK with training.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov identifier no. NCT03019796, January 13, 2017.

High-intensity interval training improves metabolic syndrome and body composition in outpatient cardiac rehabilitation patients with myocardial infarction

BACKGROUND

To examine the effect of high-intensity interval training (HIIT) on metabolic syndrome (MetS) and body composition in cardiac rehabilitation (CR) patients with myocardial infarction (MI).

METHODS

We retrospectively screened 174 consecutive patients with MetS enrolled in CR following MI between 2015 and 2018. We included 56 patients who completed 36 CR sessions and pre-post dual-energy X-ray absorptiometry. Of these patients, 42 engaged in HIIT and 14 in moderate-intensity continuous training (MICT). HIIT included 4-8 intervals of high-intensity (30-60 s at RPE 15-17 [Borg 6-20]) and low-intensity (1-5 min at RPE < 14), and MICT included 20-45 min of exercise at RPE 12-14. MetS and body composition variables were compared between MICT and HIIT groups.

RESULTS

Compared to MICT, HIIT demonstrated greater reductions in MetS (relative risk = 0.5, 95% CI 0.33-0.75, P < .001), MetS z-score (- 3.6 ± 2.9 vs. - 0.8 ± 3.8, P < .001) and improved MetS components: waist circumference (- 3 ± 5 vs. 1 ± 5 cm, P = .01), fasting blood glucose (- 25.8 ± 34.8 vs. - 3.9 ± 25.8 mg/dl, P < .001), triglycerides (- 67.8 ± 86.7 vs. - 10.4 ± 105.3 mg/dl, P < .001), and diastolic blood pressure (- 7 ± 11 vs. 0 ± 13 mmHg, P = .001). HIIT group demonstrated greater reductions in body fat mass (- 2.1 ± 2.1 vs. 0 ± 2.2 kg, P = .002), with increased body lean mass (0.9 ± 1.9 vs. - 0.9 ± 3.2 kg, P = .01) than the MICT. After matching for exercise energy expenditure, HIIT-induced improvements persisted for MetS z-score (P < .001), MetS components (P < .05), body fat mass (P = .002), body fat (P = .01), and lean mass (P = .03).

CONCLUSIONS

Our data suggest that, compared to MICT, supervised HIIT results in greater improvements in MetS and body composition in MI patients with MetS undergoing CR.

Training intensity relative to ventilatory thresholds determines cardiorespiratory fitness improvements in sedentary adults with obesity

The aim of the present study was to study if training intensity relative to ventilatory thresholds (VTs) determines the improvements in cardiorespiratory fitness (CRF) in middle-aged sedentary individuals with obesity. Before and after 16-weeks of HIIT (43-min alternating bouts at 70/90% of HR_MAX), oxygen consumption ( V˙ O₂) and heart rate (HR) at ventilatory threshold 1 ( V˙ O_2VT1, HR_VT1), ventilatory threshold 2 ( V˙ O_2VT2, HR_VT2) and at maximal effort ( V˙ O_2MAX, HR_MAX) were assessed during a graded cycle-ergometer exercise test. Retrospectively, participants were divided into two groups based on whether training intensities were under (UNDER; n = 39) or over (OVER; n = 37) VT₁ and VT₂. At baseline, age, body composition, V˙ O_2VT1, V˙ O_2VT2, and HR_MAX were similar in both groups. However, V˙ O_2MAX was higher in OVER (P = 0.033), whereas HR_VT1 and HR_VT2 were higher in UNDER (P < 0.05). V˙ O_2MAX (9.0%) and HR_MAX (2.2%) improved similarly in both groups. V˙ O_2VT1 and V˙ O_2VT2 improved with training in both groups (P < 0.001) but the improvement was larger in OVER versus UNDER in V˙ O_2VT1 (P = 0.013) and tended to be higher in V˙ O_2VT2 (P = 0.068). HR_VT1 increased only in OVER (P < 0.001), whereas HR_VT2 did not change in any group (P = 0.248). A 16-week programme of HIIT improves V˙ O_2MAX similarly in individuals training at intensities over or under their VTs. However, individuals training over their VTs showed a larger improvements in V˙ O_2VT1 expanding exercise workloads fuelled by oxidative metabolism.