Table 3.
Relative composition of major sphingolipid classes in meibum and tears grouped by meibum quality.
| Sphingolipid Species |
Good Quality (N=25) Mole Percent |
Poor Quality (N=25) Mole Percent |
P-Value | ||
|---|---|---|---|---|---|
| Median | IQR | Median | IQR | ||
| Meibum | |||||
| Cer | 17.1 | 8.6 | 15.1 | 6.7 | 0.09 |
| Hex-Cer | 4.9 | 3.8 | 3.8 | 1.0 | 0.02 |
| SM | 65.8 | 13.2 | 75.9 | 6.3 | <0.005 |
| Sph | 8.2 | 6.2 | 4.3 | 2.7 | <0.005 |
| Sa | 3.3 | 3.1 | 1.8 | 1.7 | 0.006 |
| Cer/SM* | 0.25 | 0.18 | 0.20 | 0.10 | 0.02 |
| Hex-Cer/SM* | 0.07 | 0.09 | 0.05 | 0.02 | 0.007 |
| Cer:Hex-Cer* | 3.45 | 2.02 | 3.90 | 2.97 | 0.11 |
| Tears | |||||
| Cer | 11.9 | 7.2 | 12.6 | 6.6 | 0.98 |
| Hex-Cer | 2.5 | 2.6 | 3.6 | 2.8 | 0.049 |
| SM | 75.0 | 8.1 | 77.4 | 10.0 | 0.07 |
| Sph | 3.4 | 2 | 4.5 | 5 | 0.07 |
| S1P | 4.6 | 3.9 | 2.0 | 5.6 | 0.02 |
| Cer/SM* | 0.17 | 0.10 | 0.16 | 0.09 | 0.48 |
| Hex-Cer/SM* | 0.03 | 0.03 | 0.05 | 0.04 | 0.09 |
| Cer:Hex-Cer* | 4.76 | 5.39 | 3.86 | 2.64 | 0.19 |
SPL=total sphingolipid; Cer=ceramide; Hex-Cer=hexosyl ceramide; SM=sphingomyelin; Sph=sphingosine; Sa=sphinganine; S1P=sphingosine 1-phosphate; IQR=interquartile range. Bioactive SPL.
*
Ratios were first calculated for each individual and then mean ratios were compared between groups