TABLE 2.
Adjusted least-square means of change in inflammation and oxidative stress score per averaged dietary protein in quartile categories of intake in 2061 participants of the Framingham Heart Study Offspring cohort1
| Quartile category of protein intake2 | ||||||
|---|---|---|---|---|---|---|
| Dietary intake | Model3 | Q1 | Q2 | Q3 | Q4 | P-trend |
| Protein, g/d | 1 | 0.766 ± 0.172 | 0.575 ± 0.176 | 0.369 ± 0.179 | 0.310 ± 0.185 | 0.02 |
| 2 | 0.839 ± 0.258 | 0.598 ± 0.252 | 0.362 ± 0.254 | 0.284 ± 0.252 | 0.007 | |
| 3 | 0.813 ± 0.261 | 0.583 ± 0.253 | 0.362 ± 0.254 | 0.313 ± 0.255 | 0.02 | |
| Animal protein, g/d | 1 | 0.624 ± 0.176 | 0.655 ± 0.175 | 0.410 ± 0.176 | 0.402 ± 0.184 | 0.19 |
| 2 | 0.651 ± 0.258 | 0.644 ± 0.251 | 0.389 ± 0.253 | 0.360 ± 0.254 | 0.11 | |
| 3 | 0.702 ± 0.261 | 0.642 ± 0.251 | 0.362 ± 0.253 | 0.313 ± 0.258 | 0.05 | |
| Plant protein, g/d | 1 | 0.784 ± 0.170 | 0.473 ± 0.178 | 0.524 ± 0.180 | 0.227 ± 0.183 | 0.01 |
| 2 | 0.822 ± 0.252 | 0.479 ± 0.257 | 0.513 ± 0.253 | 0.196 ± 0.253 | 0.006 | |
| 3 | 0.891 ± 0.254 | 0.508 ± 0.257 | 0.519 ± 0.252 | 0.141 ± 0.254 | 0.001 | |
Values are least-square adjusted means ± SEs of the outcome, the change in the inflammation and oxidative stress score, modeled as the difference in the score between examination 8 and examination 7. The score is the sum of rank-normalized values of CRP, OPG, ICAM-1, IL-6, MCP-1, LPL-A2 mass and activity, P-selectin, and TNFRII. A higher value of the outcome indicates a larger change (increase) in inflammation/oxidative stress, whereas a lower value indicates a smaller change (increase if positive, decrease if negative), and thus less inflammation/oxidative stress. CRP, C-reactive protein; CVD, cardiovascular disease; ICAM-1, soluble intracellular adhesion molecule 1; LPL-A2, lipoprotein phospholipase A2; MCP-1, monocyte chemoattractant protein 1; NSAID, nonsteroidal anti-inflammatory drug; OPG, osteoprotegerin; TNFRII, tumor necrosis factor receptor II.
Median values in quartile categories of intake were as follows: for total protein, 67.4, 77.3, 85.0, and 95.9 g/d; for animal protein, 42.6, 52.5, 60.3, and 71.6 g/d; and for plant protein, 19.8, 22.9, 25.5, and 29.9 g/d.
Models were adjusted as follows: 1) age, sex, energy intake, smoking status, and the baseline (examination 7) value of the score; 2) baseline physical activity, NSAID use, BMI, cardiovascular disease history, treatment for hypertension, diabetes, or dyslipidemia, and alcohol intake; 3) glycemic index, and the PUFA:SFA ratio. For animal and plant protein, model 3 was also adjusted for the other protein source (e.g., animal protein adjusted for plant protein as well as glycemic index and the PUFA:SFA ratio).