Table 2.
Separate analyses based on control group for comparing biochemical indicator levels in blood and CSF
| Biochemical indicator | vs HC | vs ONDsa | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of studies | No. of ALS/controls | WMD | Lower 95%CI | High 95% CI | p value | No. of studies | No. of ALS/controls | WMD | Lower 95%CI | High 95% CI | p value | |
| Total cholesterol | 16 | 2762/4479 | 3.98 | −3.48 | 11.44 | 0.30 | 1 | 39/66 | 10.87 | −1.22 | 22.96 | 0.08 |
| LDL-C | 13 | 2677/4347 | 0.46 | −6.56 | 7.47 | 0.90 | 0 | NA | NA | NA | NA | NA |
| HDL-C | 14 | 2707/4376 | 1.67 | −0.89 | 4.24 | 0.20 | 0 | NA | NA | NA | NA | NA |
| TG | 11 | 2366/2261 | 0.11 | −9.15 | 9.37 | 0.98 | 0 | NA | NA | NA | NA | NA |
| Fasting blood glucose | 8 | 220/204 | 0.13 | 0.05 | 0.21 | 0.001 | 1 | 81/37 | 0.20 | −0.23 | 0.63 | 0.37 |
| Fasting insulin | 6 | 94/88 | −6.79 | −29.27 | 15.70 | 0.55 | 0 | NA | NA | NA | NA | NA |
| CSF glucose | 1 | 20/20 | −0.05 | −0.37 | 0.27 | 0.76 | 2 | 112/71 | 0.06 | −0.10 | 0.21 | 0.45 |
| CSF total proteinb | 0 | NA | NA | NA | NA | NA | 5 | 312/153 | −1.45 | −5.13 | 2.24 | 0.44 |
| Qalb | 1 | 14/20 | 2.00 | −2.94 | 6.94 | 0.43 | 5 | 508/180 | 0.46 | −0.55 | 1.47 | 0.37 |
| Serum albumin | 3 | 630/611 | −1.52 | −5.53 | 2.48 | 0.46 | 0 | NA | NA | NA | NA | NA |
| Serum total protein | 3 | 705/690 | −0.44 | −1.03 | 0.14 | 0.14 | 0 | NA | NA | NA | NA | NA |
| Serum ferritin | 9 | 1638/1217 | 63.43 | 48.12 | 78.73 | < 0.001 | 2 | 572/255 | 58.72 | 29.23 | 88.21 | < 0.001 |
| Serum transferrinc | 6 | 974/659 | −0.13 | −0.17 | −0.08 | < 0.001a | 2 | 184/83 | 0.81 | −1.34 | 2.96 | 0.46 |
| Serum iron | 6 | 974/659 | 0.34 | −0.68 | 1.37 | 0.51 | 1 | 72/38 | −0.49 | −2.70 | 1.71 | 0.66 |
| TIBC | 3 | 236/304 | −2.42 | −3.93 | −0.90 | 0.002 | 1 | 72/38 | −1.74 | −5.39 | 1.91 | 0.35 |
| TSC % | 3 | 858/486 | 2.79 | 1.52 | 4.05 | < 0.001 | 0 | NA | NA | NA | NA | NA |
| Creatine kinase | 5 | 229/1843 | 80.29 | 32.90 | 127.67 | 0.001 | 0 | NA | NA | NA | NA | NA |
Abbreviations: ALS amyotrophic lateral sclerosis, CI confidence interval, CSF cerebrospinal fluid, HC healthy control, HDL-C high-density lipoprotein cholesterol, LDL-C low-density lipoprotein cholesterol, NA not available, OND other neurological disease, Qalb CSF/serum albumin quotient, TG triglyceride, TIBC total iron-binding capacity, TSC% transferrin saturation coefficient, WMD weighted mean difference
a: ONDs are other neurological diseases excluding ALS-related disease. Note: only one study compared ALS with lower motor neuron disease on total protein in CSF [Süssmuth. S. 2010]
b: Süssmuth. S et al. compared total protein in CSF and Qalb between ALS patients and lower motor neuron disease but the results did not have statistical significance (CSF total protein: WMD = −6.90, 95% CI [− 36.23–22.43], p = 0.65; Qalb: WMD = 2.00, 95% CI [−2.94–6.94], p = 0.47)
c: By performing a separate analysis based on control group, serum transferrin showed a significant decrease in ALS patients compared with healthy controls other than ONDs