Low Plasma Lysophosphatidylcholine Levels Are Associated With Reduced Handgrip Strength in Older Outpatients

To examine the association between plasma phospholipid profiles and diagnostic elements of sarcopenia, namely muscle mass and strength, in older outpatients.

We conducted a cross-sectional study of patients aged 65 years or older at a frailty clinic in Japan. Fasting plasma phospholipids (phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol) and lysophospholipids (lysophosphatidylcholine [LPC] and lysophosphatidylethanolamine [LPE]) were quantified. Muscle mass was assessed using bioelectrical impedance, while handgrip strength (HGS) was measured using a dynamometer. Sarcopenia was classified using cut-off values established for Asian populations. Group differences were analyzed using unpaired t tests. Logistic regression-estimated odds ratios (ORs) for lipid tertiles (highest as reference) were adjusted for age, sex, comorbidity, total cholesterol level, and C-reactive protein level.

We analyzed data from 185 participants (mean age 79.5 ± 6.7 years; 61.6% women). Sarcopenia was identified in 26.5% of the patients. However, the LPC tertiles were not independently associated with sarcopenia. No phospholipid class was associated with low muscle mass. Conversely, the low HGS group demonstrated significantly lower levels of total LPC and LPE, as well as individual species LPC (16:0, 18:0, and 18:2) compared to the normal HGS group. In adjusted models, the lowest tertile exhibited higher odds of low HGS for total LPC (OR: 2.46; 95% confidence interval [CI]: 1.02-5.94; p = 0.045), LPC 18:0 (2.73; 1.13-6.62; p = 0.026), and LPC 18:2 (2.57; 1.07-6.19; p = 0.035).

Lower plasma LPC, particularly 18:0 and 18:2, was independently associated with reduced HGS, supporting its role as a potential biomarker and nutritional target in older outpatients.