Normative values of skeletal muscle indices for nutritional assessment and implications on definition of sarcopenia in Indian adult population.

Abstract

Sarcopenia is defined as both low muscle function (performance or strength) and low muscle mass. Although aging is the main cause of sarcopenia, it can also occur due to poor nutrition and chronic diseases like liver cirrhosis, chronic kidney disease, and diabetes. To do the quantitative analysis of various normative skeletal muscle indices (to define sarcopenia) in the Indian population. Sex-specific means, standard deviations (SD), and sarcopenia cutoffs (mean-2SD) of psoas muscle thickness (PMTH), psoas muscle area (PMA), psoas muscle index (PMI), erector spinae muscle area (ESMA), skeletal muscle radiation attenuation (SMRA), total skeletal muscle area (SMA), and total skeletal muscle index (SMI) were computed. A total of 2002 individuals (1308 males and 694 females) underwent CT evaluation. PMTH (mm/m) was observed to be 15.87±2.67 in males vs. 12.61±2.46 in females (p=0.0001); PMA (cm2) was 18.55±3.45 in males vs.13.52±2.80 in females (p=0.0001); PMI (cm2/m2) was 6.69±1.40 in males vs. 5.57±1.18 in females (p=0.0001); ESMA (cm2) was 45.74±6.01 in males vs. 35.37±5.63 in females (p=0.0001); ESMI (cm2/m2) was 16.5±2.55 in males vs. 14.62±2.6 in females (p=0.0001); SMRA was 55.80±3.91 Hounsfield unit (HU) in males vs. 52.36±3.67 HU in females (p=0.0001); SMA (cm2) was 147.73±11.77 in males vs. 106.33±12.00 in females (p=0.0001); and SMI (cm2/m2) was estimated to be 51.00±5.70 in males vs. 43.93±6.05 in females (p=0.0001). PMTH, PMI, ESMI, SMI, and SMRA cutoffs for sarcopenia at L3 were observed to be 10.53 mm/m, 3.89 cm2/m2, 11.40 cm2/m2, 39.59 cm2/m2, and 47.98 HU among males and 7.69, 3.20, 9.42, 31.83, and 45.01 among females, respectively; these values wereconsistent with previously reported cutoffs in Indian studies but not consistent with the cutoffs reported in other countries. Normative values of skeletal muscle indices for either sex among the Indian adult population would enable future studies on sarcopenia in various medical conditions.