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

Kitzman DW, Brubaker P, Morgan T, et al.
JAMA. 2016;315(1):36-46

Background

Obesity is an independent heart failure risk factor [1,2]. A recent study reported that older patients with heart failure with preserved ejection fraction (HFpEF) have more thigh intermuscular fat and a higher intermuscular fat to skeletal muscle ratio compared with healthy volunteers [3]. These parameters were significantly related to impaired peak Vo₂ in HFpEF patients [3], a strong determinant of prognosis and reduced quality of life (QOL) in these patients [4].
The value of weight loss with diet for patients with heart failure is controversial [5], and current guidelines do not include diet recommendations [6], although in obese older individuals without heart failure, weight loss improves diastolic function and exercise capacity [7,8].
The objective of this study was to examine the effects of diet, or physical exercise, or both, on exercise capacity and quality of life, in obese older patients with HFpEF.

Main results

• Peak VO₂ was increased significantly by both interventions:
  - Exercise: 1.2 mL/kg body mass/min (95%CI: 0.7-1.7), P < .001
  - Diet: 1.3 mL/kg body mass/min (95%CI: 0.8-1.8), P < .001
• The effect of the combination of exercise and diet was additive. (Peak VO₂ joint effect: 2.5 mL/kg/min).
• The change in peak VO₂was positively correlated with
  - the change in percent lean body mass (r = 0.32; P = .003)
  - the change in thigh muscle to intermuscular fat ratio (r = 0.27; P = .02):
• Bodyweight decreased by
  - 7% (7 kg [SD: 1]) in the diet group
  - 3%(4 kg [SD: 1]) in the exercise group,
  - 10% (11 kg [SD: 1] in the exercise + diet group, and
  - 1% (1 kg [SD: 1]) in the control group
• There was no statistically significant change in the Minnesota Living With Heart Failure total score with exercise and with diet:
  - Exercise: −1 unit [95%CI: −8 to 5], P = .70
  - Diet: −6 units [95%CI: −12 to 1], P = .08
• Other quality of life measures: Diet significantly improved
  - the KCCQ score, a heart failure–specific QOL measure, by 7 units (95% CI: 2.6-12.3, P = .004)
  - the general QOL SF-36 physical component score by 4 units (95% CI: 1-7), P = .02

Conclusion

Diet or physical exercise lead to improved exercise capacity in older obese patients with HFpEF. The combination of diet and exercise may have an additive benefit. Neither diet, nor exercise improved the quality of life according to the Minnesota Living with Heart Failure questionnaire, however, diet significantly improved the outcomes of the KCCQ and the SF-36 scores.

Editorial comment [9]

In HFpEF patients cardiovascular pathophysiology is impaired both centrally, as well as in the periphery. The latter has not been addressed as therapeutic targets is these patients.
Dietary interventions in HFpEF are currently related mainly to sodium restriction, although there is evidence supporting a beneficial effect of caloric restriction.
This report provides additional evidence that a more comprehensive dietary intervention with or without exercise training improves exercise capacity in older and obese HFpEF patients, and that the combination of both interventions has an additive effect. The hypothesis is very interesting and should be tested in a larger population. The future implementation of dietary intervention and exercise training in HFpEF patients could include the use of modern and high-tech approaches, like for example digital technologies (smartphone applications, wrist-worn exercise monitors, etc.). Financial aspects and the integration of these methods into heart failure management programs should also be addressed.

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References

1. Morkedal B, Vatten LJ, Romundstad PR, et al. Risk of myocardial infarction and heart failure among metabolically healthy but obese individuals. J AmColl Cardiol.2014;63(11):1071-1078.
2. Kenchaiah S, Evans JC, Levy D, et al. Obesity and the risk of heart failure. N Engl J Med. 2002;347(5):305-313.
3. Haykowsky MJ, Kouba EJ, Brubaker PH, et al. Skeletal muscle composition and its relation to exercise intolerance in older patients with heart failure and preserved ejection fraction. Am J Cardiol. 2014;113(7):1211-1216.
4. Upadhya B, Haykowsky MJ, Eggebeen J, et al. Exercise intolerance in heart failure with preserved ejection fraction: more than a heart problem. J Geriatr Cardiol. 2015 May; 12(3): 294–304.
5. Haass M, Kitzman DW, Anand IS, et al. Body mass index and adverse cardiovascular outcomes in heart failure patients with preserved ejection fraction. Circ Heart Fail. 2011;4(3):324-331.
6. Yancy CW, Jessup M, Bozkurt B, et al. 2013 ACCF/AHA guideline for the management of heart failure. J AmColl Cardiol. 2013;62(16):e147-e239.
7. Normandin E, Houston DK, Nicklas BJ. Caloric restriction for treatment of geriatric obesity. Curr Nutr Rep. 2015;4(2):143-155.
8. Villareal DT, Chode S, Parimi N, et al. Weight loss, exercise, or both and physical function in obese older adults. N Engl J Med. 2011;364(13):1218-1229.
9. Wenger NK. Lifestyle Interventions to Improve Exercise Tolerance in Obese Older Patients With Heart Failure and Preserved Ejection Fraction. JAMA. 2016;315(1):31-33.