We read with interest the article by Vaibhaw et al.1 which has described a high post–liver transplant morbidity in recipients with sarcopenia on the basis of skeletal muscle index (SMI) cutoffs of <52.4 cm2/m2 for men and <38.5 cm2/m2 for women. They demonstrated that almost half (48%) of the patients who underwent liver transplant (LT) at their center over a period of two years had sarcopenia.
Bejamin et al. have reiterated the importance of ethnicity and gender specific reference standards for an accurate diagnosis of sarcopenia because of fundamental differences in the diet, body habitus, and physical activity of different populations.2 They have derived a lower cutoff of 36.54 and 30.21 cm2/m2 from healthy men and women, respectively.2 Using these cutoffs in patients with alcoholic liver cirrhosis of north-Indian descent, the prevalence of sarcopenia was reported to be 12.8%. This is similar to the cutoffs (28.15 cm2/m2 in men and 26.0 cm2/m2 in women by taking below the 5th percentile) of SMI derived by us after analyzing the preoperative computerized tomography (CT) scans of 110 healthy Indian liver donors. We believe that using these cutoffs, the prevalence of sarcopenia among Indian patients with end stage liver disease (ESLD) presenting for LT would be much lower than the 48% described by Vaibhaw et al.1 Because of the use of higher cutoffs, they found no difference in mortality between sarcopenic and non-sarcopenic patients although SMI stood out as an independent predictor of post-transplant mortality on multivariate analysis in their study.
The cutoffs of SMI, used by Vaibhaw et al.1 (52.4 cm2/m2 for men; 38.5 cm2/m2 for women), were described by Prado3 to study the impact of sarcopenic obesity on mortality in cancer patients in Canadian population which differs significantly in terms of ethnicity and nutritional status from the Indian population. Similarly the use of SMI cutoffs endorsed by the North American expert panel to define sarcopenia in liver transplantation,4 (SMI <50 cm2/m2 for men and <39 cm2/m2 for women) derived by its impact on mortality in North American Caucasian patient population would also not be applicable to our population for the same reasons.
Sidhu et al.5 have derived the cutoff values of sarcopenic parameters—muscle mass, strength, and performance from North Indian population to identify high risk of mortality in sarcopenic patients with ESLD. They too have reported a lower mean SMI value among non-survivors, 24.12 (3.86) cm2/m2, than the western literature emphasizing the need to derive and use cutoffs.5 Thus we wish to submit that prevalence of sarcopenia in our patients can be reported accurately only when the cutoffs are derived from the Indian population.
CRediT authorship contribution statement
Shweta A. Singh: Methodology, Resources, Writing - original draft, Visualization, Writing - review & editing. Kaushal Madan: Conceptualization, Supervision. Ruchi Rastogi: Software, Validation, Formal analysis, Data curation, Investigation. Abhishek R. Agarwal: Software, Validation, Formal analysis, Data curation, Investigation. Subhash Gupta: Writing - review & editing, Supervision, Validation, Resources. Ruchika Thakur: Formal analysis, Data curation.
Conflicts of interest
The authors have no conflicts of interest to declare.
References
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