Table 2:
Analyses of Body Mass Index at Enrollment and ALS Death in Men and Women
| Continuous BMI per 5 kg/m2 Increment | World Health Organization Categories of BMI (kg/m2) | ||||||
|---|---|---|---|---|---|---|---|
| 14–<18.5ǂ | 18.5–<23 (reference) | 23–<25 | 25–<30 | 30+ | |||
| All | No. of cases | 616 | 14 | 178 | 127 | 214 | 67 |
| RR (95% CI) | 0.85 (0.76 – 0.95) | 2.56 (1.38 – 4.77) | 1.00 | 0.74 (0.58 – 0.95) | 0.75 (0.58 – 0.95) | 0.73 (0.53 – 1.00) | |
| p-value | 0.005 | 0.003 | 0.016 | 0.017 | 0.053 | ||
| p-H between studies | 0.486 | 0.411 | 0.533 | 0.294 | 0.368 | ||
| p-H due to sex | 0.417 | 0.285 | 0.179 | 0.172 | 0.662 | ||
| Three year lag | No. of cases | 556 | 8 | 161 | 112 | 196 | 64 |
| RR (95% CI) | 0.90 (0.80 – 1.01) | 1.81 (0.87 – 3.77) | 1.00 | 0.74 (0.57 – 0.95) | 0.79 (0.63 – 0.98) | 0.79 (0.58 – 1.09) | |
| p-value | 0.081 | 0.112 | 0.020 | 0.035 | 0.146 | ||
| p-H between studies | 0.617 | 0.621 | 0.705 | 0.731 | 0.629 | ||
| p-H due to sex | 0.978 | 0.566 | 0.201 | 0.336 | 0.965 | ||
| Five year lag | No. of cases | 497 | 8 | 142 | 103 | 173 | 56 |
| RR (95% CI) | 0.89 (0.79 – 1.01) | 2.16 (1.03 – 4.52) | 1.00 | 0.76 (0.58 – 1.00) | 0.79 (0.62 – 1.00) | 0.79 (0.56 – 1.11) | |
| p-value | 0.06 | 0.042 | 0.047 | 0.05 | 0.176 | ||
| p-H between studies | 0.680 | 0.616 | 0.645 | 0.689 | 0.504 | ||
| p-H due to sex | 0.872 | 0.666 | 0.201 | 0.211 | 0.915 | ||
| Seven year lag | No. of cases | 414 | 7 | 117 | 86 | 145 | 47 |
| RR (95% CI) | 0.89 (0.78 – 1.02) | 2.24 (1.02 – 4.93) | 1.00 | 0.80 (0.58 – 1.10) | 0.78 (0.60 – 1.02) | 0.83 (0.57 – 1.20) | |
| p-value | 0.091 | 0.045 | 0.168 | 0.07 | 0.320 | ||
| p-H between studies | 0.872 | 0.700 | 0.393 | 0.662 | 0.608 | ||
| p-H due to sex | 0.966 | 0.534 | 0.238 | 0.359 | 0.836 | ||
| Non-smokers | No. of cases | 486 | 11 | 137 | 96 | 177 | 65 |
| RR (95% CI) | 0.87 (0.76 – 1.00) | 2.91 (1.19 – 7.14) | 1.00 | 0.69 (0.52 – 0.91) | 0.73 (0.55 – 0.95) | 0.74 (0.50 – 1.10) | |
| p-value | 0.05 | 0.020 | 0.009 | 0.020 | 0.140 | ||
| p-H between studies | 0.292 | 0.187 | 0.675 | 0.269 | 0.185 | ||
| p-H due to sex | 0.327 | 0.091 | 0.111 | 0.069 | 0.478 | ||
Multivariable RRs were further adjusted for smoking status (ever smoking and smoking pack years <10, 10–<20, 20–<30, 30–<40, 40+), level of education attained (<high-school, high-school, >high-school), physical activity (low, moderate, high), and race (if appropriate to the cohort); age in years and year of questionnaire return were included as stratification variables.
MCCS-females are not part of the categorical analyses because no cases occurred among participants in the reference range of BMI 18.5 to <25 kg/m2. COSM, CTS, IOWA, NLCS-females, SMC, WHS are included in the analyses of BMI <18.5kg/m2; no cases occurred in the remaining cohorts. Including the non-cases in these cohorts (1.5% of overall populations) with BMI<18.5kg/m2 in the reference category did not change the results.
Abbreviations: P value for the test for between-studies heterogeneity (p-H between studies); P value for the test for between-studies heterogeneity due to sex (p-H due to sex).