Table 1.
Characteristics of patients with ALS (cases) and controls at the time of metabolic assessment
| Characteristic at time of metabolic assessment | Case/control comparison | Within-case comparison | ||||||
| ALS (n=58) | Control (n=58) | Standardised difference | P values | Hypermetabolic (n=24) | Normometabolic (n=34) | Standardised difference | P values* | |
| Demographics | ||||||||
| Age (years) | 61 (8) | 59 (8) | 0.30 | 0.11 | 60 (8) | 62 (9) | 0.33 | 0.21 |
| Sex (female) | 20 (34%) | 21 (36%) | 0.03 | 1.00 | 7 (29%) | 13 (38%) | 0.19 | 0.66 |
| BMI | 26 (4) | 27 (4) | 0.16 | 0.40 | 27 (4) | 26 (4) | 0.28 | 0.31 |
| Fat mass (%) | 36 (12) | 32 (9) | 0.36 | 0.06 | 38 (11) | 34 (12) | 0.40 | 0.13 |
| Fat-free mass (kg) | 50 (11) | 55 (12) | 0.41 | 0.03 | 49 (11) | 50 (11) | 0.08 | 0.76 |
| Metabolic index | 115 (21) | 107 (13) | 0.45 | 0.02 | 133 (9) | 102 (16) | 2.34 | <0.01 |
| Hypermetabolic (MI≥120%) | 24 (41%) | 7 (12%) | 0.70 | <0.01 | ||||
| Time since onset (months)† | 20 (2) | 17 (2) | 22 (2) | 0.38 | 0.17 | |||
| Diagnostic delay (months) | 15 (11) | 15 (10) | 15 (11) | 0.01 | 0.97 | |||
| Bulbar, yes | 15 (26%) | 5 (21%) | 10 (29%) | 0.20 | 0.67 | |||
| Clinical phenotype | ||||||||
| ALSFRS-R | 38 (4) | 38 (4) | 39 (5) | 0.30 | 0.27 | |||
| ΔFRS† | −0.5 (1.6) | −0.6 (1.5) | −0.4 (1.7) | 0.57 | 0.03 | |||
| FVC, % of predicted | 89 (19) | 88 (18) | 90 (21) | 0.10 | 0.72 | |||
| UMN score | 6 (3) | 6 (3) | 6 (3) | 0.02 | 0.94 | |||
| LMN score† | 3 (0.6) | 4 (0.3) | 3 (0.7) | 0.56 | 0.04 | |||
| King’s stage | 0.51 | 0.07 | ||||||
| 1 | 17 (29%) | 3 (12%) | 14 (41%) | |||||
| 2 | 28 (48%) | 14 (58%) | 14 (41%) | |||||
| 3 | 12 (21%) | 7 (29%) | 5 (15%) | |||||
| 4 | 1 (2%) | 0 (0%) | 1 (3%) | |||||
| Cognitive indices | ||||||||
| ECAS total score | 111 (17) | 111 (15) | 111 (14) | 0.00 | 0.99 | |||
| ECAS<105 | 9 (16%) | 3 (12%) | 6 (18%) | 0.30 | 0.67 | |||
| ACE III total score | 89 (7) | 90 (6) | 89 (6) | 0.23 | 0.33 | |||
| ACE≤82 | 2 (3%) | 0 (0%) | 2 (6%) | 0.36 | 1.00 | |||
| Familial/genetic genotype | ||||||||
| Familial | 8 (14%) | 7 (29%) | 1 (3%) | 0.76 | 0.01 | |||
| C9orf72 | ||||||||
| Missing | 10 (17%) | 4 (17%) | 6 (18%) | 0.03 | 1.00 | |||
| Repeat expansion | 5 (10%‡) | 3 (15%‡) | 2 (7%‡) | 0.25 | 0.69 | |||
| UNC13A (rs12608932) | ||||||||
| Missing | 13 (22%) | 7 (29%) | 6 (18%) | 0.27 | 0.47 | |||
| Homozygosity C allele | 5 (11%‡) | 2 (12%‡) | 3 (11%‡) | 0.03 | 1.00 | |||
Data presented as mean (SD) or n (%).
*P value is based on a two-sided Student’s t-test with Welch’s correction when comparing means and the Χ2 test with Yates’s continuity correction when comparing proportions.
†Geometric means.
‡% is based on the number of cases with genotype data. Genotyping was completed for cases and controls.
ACE III, Addenbrooke’s Cognitive Examination III; ALS, amyotrophic lateral sclerosis; ALSFRS-R, ALS Functional Rating Scale-Revised; BMI, body mass index; ECAS, Edinburgh Cognitive and Behavioural ALS Screen; ΔFRS, (ALSFRS-R—48)/disease duration from symptom onset; FVC, forced vital capacity; LMN, lower motor neuron; UMN, upper motor neuron.