Table 1.
Baseline Characteristics of the Population According to Quintiles of Total, Animal, or Plant Protein Intake as % of Energy From Protein in the InCHIANTI Study
| Total Protein | Animal Protein | Plant Protein | |||||||
|---|---|---|---|---|---|---|---|---|---|
| (n = 1 139) | Q1 (227) | Q3 (228) | Q5 (227) | Q1 (228) | Q3 (229) | Q5 (228) | Q1 (227) | Q3 (227) | Q5 (227) |
| Clinical characteristics | |||||||||
| Age (years) | 75 ± 7 | 75 ± 8 | 76 ± 7 | 74 ± 7 | 75 ± 8 | 76 ± 8† | 77 ± 8 | 76 ± 8 | 75 ± 7 |
| Women (%) | 42 | 52 | 70* | 38 | 55 | 72* | 64 | 59 | 51* |
| BMI (kg/m²)* | 27 ± 4 | 27 ± 4 | 27 ± 4 | 27 ± 4 | 27 ± 4 | 27 ± 4 | 27 ± 4 | 27 ± 4 | 27 ± 4 |
| Education (years) | 6 ± 3 | 5 ± 3 | 5 ± 3† | 6 ± 3 | 5 ± 3 | 5 ± 3 | 6 ± 4 | 5 ± 3 | 5 ± 3* |
| Economic situation (%) | |||||||||
| Cannot say | 2 | 4 | 2 | 3 | 2 | 3 | 3 | 5 | 4 |
| Bad | 34 | 31 | 27 | 30 | 34 | 31 | 39 | 28 | 23 |
| Satisfactory | 54 | 55 | 59 | 57 | 54 | 54 | 48 | 57 | 59 |
| Good | 9 | 10 | 11 | 10 | 9 | 11 | 10 | 9 | 14† |
| Current smoking (%) | 33 | 27 | 21 | 35 | 25 | 24 | 31 | 24 | 31 |
| ADL disability (%) | 6 | 11 | 12 | 3 | 11 | 15† | 13 | 12 | 6‡ |
| Physical activity (%) | |||||||||
| Sedentary | 21 | 23 | 30 | 20 | 20 | 31 | 27 | 29 | 20 |
| Light | 37 | 42 | 44 | 37 | 45 | 43 | 41 | 40 | 45 |
| Mod–high | 41 | 35 | 26 | 43 | 35 | 25 | 30 | 31 | 35 |
| Hypertension (%) | 55 | 56 | 56 | 56 | 59 | 56 | 52 | 56 | 57‡ |
| Diabetes (%) | 7 | 15 | 22* | 6 | 13 | 18* | 8 | 16 | 16† |
| IRF (%)* | |||||||||
| Mild | 27 | 32 | 33 | 25 | 33 | 33 | 34 | 33 | 27 |
| Severe | 3 | 1 | 2 | 3 | 3 | 0 | 2 | 1 | 3 |
| IHD (%) | 6 | 7 | 11‡ | 5 | 7 | 9 | 5 | 8 | 8 |
| Cerebrovascular disease (%) | 5 | 8 | 6 | 6 | 8 | 7 | 5 | 7 | 8 |
| PAD (%) | 11 | 11 | 8 | 10 | 10 | 9 | 10 | 12 | 12 |
| CHF (%) | 4 | 4 | 7‡ | 4 | 6 | 6 | 2 | 8 | 6 |
| COPD (%) | 11 | 7 | 7 | 11 | 7 | 7 | 7 | 11 | 6 |
| Cancer (%) | 5 | 3 | 7 | 4 | 7 | 8 | 5 | 5 | 3 |
| Dementia (%) | 5 | 7 | 7 | 4 | 4 | 10 | 7 | 9 | 5 |
| Cognitive impairment (%) | 23 | 31 | 38† | 21 | 31 | 40† | 35 | 32 | 31 |
| Parkinson’s disease (%) | 1 | 1 | 1 | 1 | 2 | 2 | 1 | 2 | 2 |
| Dietary characteristics | |||||||||
| Energy (103 kcal/day) | 2.1 ± 0.6 | 1.9 ± 0.5 | 1.6 ± 0.4* | 2.1 ± 0.7 | 1.9 ± 0.5 | 1.7 ± 0.5* | 1.8 ± 0.6 | 1.8 ± 0.6 | 1.9 ± 0.6 |
| Total protein (% E) | 13 ± 1 | 16 ± 1 | 19 ± 1* | 13 ± 1 | 16 ± 1 | 19 ± 1* | 16 ± 2 | 16 ± 2 | 16 ± 2 |
| Animal protein (% E) | 7 ± 1 | 10 ± 1 | 13 ± 2* | 7 ± 1 | 10 ± 1 | 14 ± 1* | 12 ± 2 | 10 ± 2 | 8 ± 2* |
| Plant protein (% E) | 5.6 ± 1.0 | 5.9 ± 1.0 | 5.7 ± 1.0 | 6.4 ± 1.0 | 5.8 ± 0.8 | 5.1 ± 0.9* | 4.3 ± 0.5 | 5.8 ± 0.1 | 7.2 ± 0.5* |
| SFA (% E) | 10 ± 2 | 10 ± 2 | 11 ± 2* | 9 ± 2 | 10 ± 2 | 12 ± 2* | 12 ± 2 | 11 ± 2 | 8 ± 2* |
| MUFA (% E) | 14 ± 3 | 15 ± 3 | 16 ± 3* | 14 ± 3 | 15 ± 3 | 17 ± 3* | 16 ± 3 | 15 ± 3 | 14 ± 3* |
| PUFA (% E) | 3.1 ± 0.7 | 3.3 ± 0.7 | 3.6 ± 0.6* | 3.0 ± 0.7 | 3.3 ± 0.6 | 3.7 ± 0.6* | 3.4 ± 0.6 | 3.4 ± 0.7 | 3.3 ± 0.7 |
| Carbohydrates (% E) | 52 ± 7 | 52 ± 6 | 47 ± 6* | 54 ± 7 | 51 ± 5 | 46 ± 6* | 46 ± 7 | 50 ± 5 | 56 ± 5* |
| Alcohol (% E) | 6 (10) | 3 (5) | 0 (3)* | 5 (10) | 3 (7) | 0 (5)* | 5 (10) | 2 (7) | 1 (4)* |
Notes: BMI = body mass index; ADL = activities of daily life; PA = physical activity; IHD = ischemic heart disease; PAD = peripheral artery disease; CHF = congestive heart failure; COPD = chronic obstructive pulmonary disease; SFA = saturated fatty acid; MUFA = monounsaturated fatty acid; PUFA = polyunsaturated fatty acid. Data for continuous variables are shown as mean ± SD or median (interquartile range). Cutoff points of intake category (percentage of total energy) for total protein were Quintile 1, <14.1%; Quintile 2, 14.1% to <15.2%; Quintile 3, 15.2% to <16.3%; Quintile 4, 16.3% to <17.6%; and Quintile 5, ≥17.6%. For animal protein were Quintile 1, <8.1%; Quintile 2, 8.1% to <9.3%; Quintile 3, 9.3% to <10.5%; Quintile 4, 10.5% to <12.0%; and Quintile 5, ≥12.0%. For plant protein were Quintile 1, <4.9%; Quintile 2, 4.9% to <5.5%; Quintile 3, 5.5% to <6.0%; Quintile 4, 6.0% to <6.6%; and Quintile 5, ≥6.6%.
*Data available in 973 subjects.
*p for trend <.001, †p for trend <.01, ‡p for trend <.05 using age- and sex-adjusted generalized linear models.