Efficacy of L-carnitine supplementation on frailty status and its biomarkers, nutritional status, and physical and cognitive function among prefrail older adults: a double-blind, randomized, placebo-controlled clinical trial

Abstract

Background

Frailty is a biological syndrome of decreased reserve and resistance to stressors due to decline in multiple physiological systems. Amino acid deficiency, including L-carnitine, has been proposed to be associated with its pathophysiology. Nevertheless, the efficacy of L-carnitine supplementation on frailty status has not been documented. Thus, this study aimed to determine the effect of 10-week L-carnitine supplement (1.5 g/day) on frailty status and its biomarkers and also physical function, cognition, and nutritional status among prefrail older adults in Klang Valley, Malaysia.

Methodology

This study is a randomized, double-blind, placebo-controlled clinical trial conducted among 50 prefrail subjects randomized into two groups (26 in L-carnitine group and 24 in placebo group). Outcome measures include frailty status using Fried criteria and Frailty Index accumulation of deficit, selected frailty biomarkers (interleukin-6, tumor necrosis factor-alpha, and insulin-like growth factor-1), physical function, cognitive function, nutritional status and biochemical profile.

Results

The results indicated that the mean scores of Frailty Index score and hand grip test were significantly improved in subjects supplemented with L-carnitine (P<0.05 for both parameters) as compared to no change in the placebo group. Based on Fried criteria, four subjects (three from the L-carnitine group and one from the control group) transited from prefrail status to robust after the intervention.

Conclusion

L-carnitine supplementation has a favorable effect on the functional status and fatigue in prefrail older adults.

Keywords:

• frailty
• Fried criteria
• Frailty Index accumulation of deficit
• L-carnitine supplementation
• prefrail elderly
• physical function
• frailty biomarkers
• randomized controlled clinical trial

Acknowledgments

We would like to acknowledge the financial support from the Ministry of Education in the Long Term Research Grant Scheme (LRGS/BU/2012/UKM-UKM/K/01) and also the direct and indirect input from the research team toward the study. We would like to extend special acknowledgments to the Malaysian older adults who agreed to participate in the study, cooperated with us during the data collection and assessment, and showed good compliance and interest to finish the study.

Disclosure

The authors report no conflicts of interest in this work.