Caloric Restriction or Aerobic Exercise Training on Peak Oxygen Consumption and Quality of Life in Obese Older Patients With HFpEF

See Also: Improving Fitness by Losing Fatness

Editor's Note: Commentary based on Kitzman DW, Brubaker P, Morgan T et al. Effect of Caloric Restriction or Aerobic Exercise Training on Peak Oxygen Consumption and Quality of Life in Obese Older Patients With Heart Failure With Preserved Ejection Fraction: A Randomized Clinical Trial. JAMA 2016;315:36-46.

Background: Only recently has it been determined that being overweight or obese is a risk factor for heart failure with preserved ejection fraction (HFpEF). Prior work in HFpEF has addressed the use of medications, hypertension control, along with diet and exercise individually. None have examined the combined effects of diet and exercise on older obese adults with HFpEF.

Funding: Federally funded (National Institute of Aging).

Methods: Single center (Wake Forest School of Medicine, Winston-Salem, NC), single blind, attention controlled trial.

Inclusion Criteria: Study participants were identified by using the medical records. Age ≥ 60 years, body mass index ≥30, left ventricular ejection fraction ≥ 50%, with predefined symptoms and signs of heart failure (NHANES criteria score of ≥32 or criteria of Rich et al3).

Exclusion Criteria: Left ventricular segmental wall motion abnormalities and significant ischemic or valvular heart disease, pulmonary disease, anemia, or other disorder that can be attributed towards patients symptoms.

Intervention:

Diet (hypocaloric diet with meals provided by the research center with deficits of 400kcal for diet group and 450 kcal for diet + exercise group).

Exercise (progressive increase in exercise intensity level (walking) with a one hour supervised session performed 3 times a week).

Primary outcome(s):

  1. Average of 3 measurements of peak oxygen consumption (mL/kg body mass/min) from last 30 seconds during peak exercise.
  2. Disease specific quality of life using the Minnesota Living with Heart Failure (MLHF) Questionnaire.

Secondary outcomes: Numerous secondary exploratory outcomes.

Blinding: All study investigators and personnel were blinded except for the biostatistician. Supervisory physician and staff were blinded to baseline results of cardiopulmonary testing. To minimize bias, standard protocol was used for obtaining maximal exercise performance.

Randomization: Computer generated, maintained by study statistician, stratified by beta-blocker medication and sex to one of four groups: exercise only (n=26), diet only (n=24), exercise + diet (n=25), or attention control (true control, n=25). Total in primary analysis from each group was slightly lower than above due to discontinuation, protocol violation, etc.

Statistical Analysis: 2x2 factorial; goal of estimating main effect of 2 interventions on 2 outcomes.

Results

1,586 patients screened. A total of 100 patients were randomly assigned to each of the 4 groups and factorial group subsequently assigned.

 

Exercise

No Exercise

Diet

Diet and exercise

Diet only

No Diet

Exercise only

No diet and no exercise

There were minimal variations in baseline covariate distribution among the 4 randomized groups.

Primary Outcome:

 

Peak oxygen consumption   
(ml/kg/minute)

      Difference  
Baseline Diet No Diet (95% CI) p-value

14.5 16.1 14.8 1.3 (0.8-1.8) <0.001

Peak oxygen consumption   
(ml/kg/minute)

      Difference  
Baseline Exercise No Exercise (95% CI) p-value

14.5 16.0 14.8 1.2 (0.7-1.7) <0.001

The combination of diet and exercise had a significant 2.5 ml/kg/minute increase in exercise capacity as measured by peak oxygen consumption when compare to baseline. This increase is suggested to be greater than the clinically meaningful increase in exercise capacity of 1.0 mL/kg/min.

The co-primary outcome of a change in MLHF as a measure of quality of life was not different between the diet and exercise arms. There were also no significant interactions noted between diet and exercise.

Conclusion: In older, obese patients, caloric restriction or exercise increased peak oxygen consumption with the possibility that the combination of diet and exercise had an incremental increase in exercise capacity.

Commentary/Perspective: The current randomized clinical trial is further evidence of the fundamental concept that non-cardiac care (diet and exercise) in the older adult with HFPEF can improve exercise capacity as measured by peak oxygen consumption. However, its lack of utility in improving the primary quality of life endpoint (MLHF score) in the older HFpEF patient needs further research.

References

  1. Kitzman DW, Brubaker P, Morgan T, et al. Effect of Caloric Restriction or Aerobic Exercise Training on Peak Oxygen Consumption and Quality of Life in Obese Older Patients With Heart Failure With Preserved Ejection Fraction: A Randomized Clinical Trial. JAMA 2016;315:36-46.
  2. Schocken DD, Arrieta MI, Leaverton PE, Ross EA. Prevalence and mortality rate of congestive heart failure in the United States. J Am Coll Cardiol 1992;20:301-6.
  3. Rich MW, Beckham V, Wittenberg C, Leven CL, Freedland KE, Carney RM. A multidisciplinary intervention to prevent the readmission of elderly patients with congestive heart failure. N Engl J Med 1995;333:1190-5.

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