Table 2. Associations Between Low-Carbohydrate-Diet Scores and Total Mortality.
| Characteristic | Quintiles of Low-Carbohydrate-Diet Scores | P for Trend | Per 20-Percentile Increase | ||||
|---|---|---|---|---|---|---|---|
| Quintile 1 | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 | |||
| Overall low-carbohydrate-diet scorea | |||||||
| Median score (IQR) | 4 (3-6) | 10 (9-11) | 15 (14-16) | 20 (19-21) | 26 (24-28) | NA | NA |
| Person-years of follow-up | 61 565 | 61 327 | 64 482 | 55 298 | 55 097 | NA | NA |
| Deaths, No. | 936 | 1047 | 1024 | 935 | 924 | NA | NA |
| Age- and sex-adjusted HR (95% CI) | 1 [Reference] | 1.00 (0.89-1.11) | 0.95 (0.83-1.08) | 1.00 (0.89-1.12) | 1.02 (0.90-1.16) | .76 | 1.01 (0.98-1.04) |
| Multivariable-adjusted HR (95% CI)b | 1 [Reference] | 0.95 (0.84-1.09) | 0.88 (0.76-1.02) | 0.90 (0.80-1.02) | 0.88 (0.76-1.02) | .06 | 0.97 (0.93-1.00) |
| Unhealthy low-carbohydrate-diet scorec | |||||||
| Median score (IQR) | 7 (4-8) | 12 (11-13) | 15 (14-16) | 18 (17-19) | 23 (22-25) | NA | NA |
| Person-years of follow-up | 58 890 | 61 281 | 51 158 | 63 288 | 63 152 | NA | NA |
| Deaths, No. | 1253 | 1181 | 845 | 918 | 669 | NA | NA |
| Age- and sex-adjusted HR (95% CI) | 1 [Reference] | 1.14 (1.01-1.27) | 1.18 (1.03-1.35) | 1.35 (1.16-1.56) | 1.36 (1.17-1.58) | <.001 | 1.13 (1.08-1.18) |
| Multivariable-adjusted HR (95% CI)b | 1 [Reference] | 1.07 (0.94-1.21) | 1.07 (0.93-1.23) | 1.18 (1.03-1.35) | 1.16 (1.00-1.34) | .01 | 1.07 (1.02-1.11) |
| Healthy low-carbohydrate-diet scored | |||||||
| Median score (IQR) | 5 (3-7) | 11 (10-12) | 16 (15-17) | 19 (18-20) | 24 (23-26) | NA | NA |
| Person-years of follow-up | 68 065 | 66 193 | 57 140 | 52 513 | 53 858 | NA | NA |
| Deaths, No. | 697 | 960 | 1096 | 1022 | 1091 | NA | NA |
| Age- and sex-adjusted HR (95% CI) | 1 [Reference] | 0.79 (0.68-0.92) | 0.83 (0.71-0.98) | 0.76 (0.65-0.89) | 0.74 (0.65-0.85) | <.001 | 0.92 (0.88-0.96) |
| Multivariable-adjusted HR (95% CI)b | 1 [Reference] | 0.83 (0.71-0.96) | 0.86 (0.73-1.01) | 0.73 (0.63-0.84) | 0.73 (0.63-0.85) | <.001 | 0.91 (0.87-0.95) |
Abbreviations: HR, hazard ratio; IQR, interquartile range; NA, not applicable.
Low total carbohydrates and high total protein and fat.
Adjusted for age (20-34, 35-49, 50-64, and ≥65 years), sex (male or female), race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, and other), educational level (less than high school, high school graduate or General Educational Development, and some college or above), ratio of family income to poverty (<1.30, 1.30-3.49, or ≥3.5), family history of diabetes mellitus (yes or no), family history of heart disease (yes or no), history of diabetes (yes or no), history of heart disease (yes or no), history of cancer (yes or no), physical activity (0, 0.1-0.9, 1.0-3.4, 3.5-5.9, or ≥6 hours per week), alcohol consumption (0, 0.1-4.9, 5-14.9, 15-29.9, or ≥30 g/d), smoking status (never smoker, former smoker, or current smoker [1-14, 15-24, or ≥25 cigarettes per day]), cholesterol (quintiles), and body mass index (calculated as weight in kilograms divided by height in meters squared) (<21, 21-24.9, 25-29.9, 30-35, and >35).
Low high-quality carbohydrate and high animal protein and saturated fat.
Low low-quality carbohydrate and high plant protein and unsaturated fat.